Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 3

[#NoPoles]

some kind of a rain/pellet mix here in old town, ABQ...i'm sure it's snow in the higher elevations of the city...there is actually quite a bit of elevation change...i live just west of the courthouse district, so every building on this street is a law office...the law office right next door, the guy must live in the swanky foothills region at the base of sandia peak...he comes to work and parks outside the house and his car has a pile of snow on the roof, when it has only been rain where i live...

[Srain]

Active day ahead across the area as the upper trough near Austin heads E and a possible surface low develops near Matagorda Bay. A warm front may move N creating a large spread in temps across the region. Areas along and S of I-10 will need to be monitored for severe storms and a possible tornado or two as the morning progresses. An active weather pattern is ahead for the week as another trough with shower/storms moves across the region on Wednesday. By Thursday, a potent Upper Low will be developing to our W near CA/AZ and strong front heads S into the Plains on Friday setting the stage for another potential wintry mischief event late Friday/early Saturday for West/Central Texas and possibly the northern areas of SE Texas as well. Winter Storm Recon has been tasked for the late week system, so expect further 'fine tuning' as the week progresses.

[Srain]

Morning e-mail from Jeff:

A series of storm systems will affect the area over the next 5-7 days…the first today!

After a bout of winter weather yesterday across much of the state including sleet locally, warm air advection overnight has greatly warmed the low level air column producing only rainfall. Strong storm system ejecting into the plains this morning will drive strong forcing/lift across the area today. The result will be widespread showers and thunderstorms.

Warm front lies across the NW Gulf this morning with offshore buoys and platforms showing dewpoints in the lower 60’s east of CRP and south of Palacios. In fact dewpoints range from 57 at Palacios to 34 at Cleveland, so there is a strong moisture gradient across the region. Strong forcing aloft will come to bear across the area later this morning which helps to create a frontal wave on the warm front over the NW Gulf. This will keep low level flow backed to the E or ESE greatly increasing low level shear profiles near and south of this boundary. Current indications is that the warm front may move inland as far as I-10 by early afternoon. Have seen before where rain north of the boundary helps delay its northward movement and keeps the near surface cold layer in tact longer. Tough call on how far inland the boundary will get, but areas near/south of the warm front will have a severe threat with low level helicity values of 500-900 m^2/s^2 which is very impressive wind shear. Overall lack of instability (CAPE less than 500 J/kg) would tend to suggest a low severe threat, but surface forcing may compensate for the lack of instability allowing updrafts to realize the low level turning. SPC has not outlooked any of our counties, but think the coastal counties and possibly the US 59 corridor counties could be at a risk for tornadoes from late morning through mid afternoon.

Following the Texas Tech meso model would suggest thunderstorms will erupt by late morning from Victoria to Columbus and push ENE across the region. Rainfall amounts of .5 to 1.0 inch is likely today, fast storm motions of 20-25mph should limit overall storm totals, but setups like this one can produce training storms…so will need to keep an eye on those area for some higher totals (over 2.0 inches).

System will exit quickly to the east tonight, but the break will be short as the trough out west reloads and send the next storm system across TX on Wednesday. Warm front will swing northward on Tuesday with deep moisture returning to the area. Strong forcing and a Pacific cold front will arrive on Wednesday afternoon/evening and this combined with moisture levels approaching the 99th percentile (PWS of 1.5-1.7 inches) and better instability (CAPE of 1000 J/kg) appears to support a better threat of strong to severe storms and heavy rainfall. Best forcing appears to be just NE of our area over northern Louisiana and NE TX and this is where the best severe weather potential may be.

Wednesday system is into Louisiana by early Thursday and then the next system in the series drops into the SW US and ejects eastward this weekend. This final system appears to dig further south keeping much of the state in the cold air mass behind the Thursday morning front. For now will go with increasing clouds Friday with light rainfall developing from SW to NE Friday night into Saturday. If the system digs even more to the south, then much of the rainfall could remain offshore and along the coast.

[wxmx]

Low after low after low...that's the pattern that will be locked in for the region.

[#NoPoles]

Low after low after low...that's the pattern that will be locked in for the region.

that's for sure...only 24hrs between storms...nws through a winter storm watch up and mentioned the possibility of thunder snow...not for the city..but for the higher mesas and mtns...

[Srain]

Morning e-mail from Jeff:

One storm system has passed through the region yesterday only to be followed closely by the next storm. If you are going to end a drought….this is the way to do it!

Dense radiation fog will lift and burn off by mid morning with partly cloudy skies and warm for the afternoon hours…highs reaching into the mid 70’s after a cold period over the weekend. Next upper level storm is loading into the SW US currently and will swing across TX on Wednesday in this highly progressive yet favorable southern storm track…not common during La Nina winters…but we will take the rain! Moisture return ramps up this evening as winds increase from the SE pumping 60 degree dewpoint air mass over the NW Gulf inland. Expect dewpoints to rises above nearshore water temperatures by late afternoon with the formation of dense sea fog along the coast. This sea fog will spread inland after dark and likely persist into midday Wednesday along the coast and in the bays.

Upper level trough ejects over TX on Wednesday with tail end dynamics and cold front moving across SE TX during the mid morning to late afternoon hours. Favroable Gulf inflow will bring strong moisture return late tonight/early Wednesday with PWS peaking in the 1.4-1.6 inch range. Main dynamics are pointed more toward the mid-MS valley area, but enough clip SE TX especially north of I-10 and east of I-45 to get some decent looking storms going. I am a little wary of the 850mb winds showing a SSW to even SW direction on Wednesday which is usually more of a drying and capping direction from NE MX. Local Texas Tech 3km meso model shows a corridor of 1000-1500 J/kg of CAPE along the US 59 corridor tomorrow early afternoon, but shows the strongest storms north of I-10 or in the region of best forcing/lift. This model did very well with the event yesterday and will follow it closely as it matches overall decent with the GFS and the NAM runs.

With this in mind will favor areas north of I-10 and east of I-45 for the best rain chances on Wednesday and also a risk of severe thunderstorms capable of hail and wind damage. SPC slight risk DAY 2 outlook does include our north and eastern counties and this is matching well to what appears to be the SW extent of a larger severe weather outbreak over the mid south into Wednesday night. Activity will become more scattered to isolated toward the southwest where moisture will be the least favorable along with weaker upper level dynamics. Another decent soaking rainfall looks likely especially north of I-10 where amounts of .5-1.0 inch will be possible with a few totals up to 2.5 inches under the stronger storms.

Another quick break on Thursday, before yet another system heads east out of the SW US Friday-Saturday with another chance of wetting rains. This system looks much colder with surface low pressure forming along the Wednesday front over the NW Gulf and this moisture being pushed up and over a cold dome at the surface (overrunning). Timing of the main upper level trough and coastal surface low look out of phase, but once again strong dynamics in the sub-tropical flow aloft may help compensate for an otherwise modest rain setup. Will go with increasing clouds early Friday with light rainfall developing from SW to NE Friday evening. Elevated instability will come into play Friday night/Saturday morning as the Gulf surface low pushes warm moist air up and over the cold dome. Some thunderstorms will be possible at this point. Coastal areas will be favored for the main bulk of this rain event with 1-2 inches possible along the coast and much higher amounts offshore. Should the system move a bit further north and the surface low track closer to the coast, a significant increase in the rainfall amounts will be needed across much of SE TX as current offshore amounts are on the high side.

This system should be east of the area by late Saturday with a break on Sunday before yet another system arrives early next week.

[Ed Lizard]

Happiness and hope abounds as SWODY 2 mid day update adds all of HGX CWA to 'SLIGHT RISK' area.

Waiting on my AccuWx PPV Euro graphics to upgrade, but the 18Z temp of 70ºF, DP 67ºF and 850 mb RH over 90% with rainfall before and after 18Z gives me hope for surface based storms.

GFS has a nice hail look at 18Z tomorrow, TT of 53, and 60 knots speed shear in the juicy part of the CAPE region, although unimpressive low level instability...

[Srain]

Afternoon e-mail from Jeff regarding the drought and its effects across Texas...

Significant improvement made to the ongoing drought across the region as the wet weather pattern that developed in late October brings widespread wetting rainfalls.

As of Feb 7, 2012, only 23% of the state is considered in D4 or exceptional drought (the worst of the drought categories) which is a massive improvement from late summer 2011 when 86% of the state was in D4 conditions. Most of SE TX has transitioned from D 4 to D3 (extreme) and D2 (severe drought). D4 exceptional drought continues to hang on however in the area from Houston and Walker counties WSW across Grimes and Washington counties and then from Jackson across Calhoun counties and southward down the TX coast. Much of the areas west of I-45 remain in extreme drought while areas east of I-45 have moved into severe to moderate drought. Across the central part of the state, drought continues remain significant, while most of N TX has been removed from drought conditions by the recent rainfall.

While short term gains have been large, the longer term averages continue to show very large rainfall deficits of 30-50 inches across SE TX for the past 2 years. In fact this region and especially east TX has been dry since the passage of Hurricane Ike in 2008.

Rainfall has been averaging near to above average east of a line from College Station to Katy to Galveston so far in 2012. In fact Houston IAH has recorded over 9 inches of rainfall in December and January which is more rainfall in those two months than for the entire period from Feb-Sept 2011 when only 7.18 inches of rain fell.

2011 Driest Years:

BUSH IAH ended 2011 as the 3rd direst year on record with a total of 24.57 inches of rainfall (49.77 inches is normal)

Hobby Airport ended the year as the driest year ever with 25.41 inches of rainfall (surpassing the record of 26.65 inches in 1988)

Laredo: driest year ever with 6.66 inches of rainfall (old record was 8.40 inches in 1917)

Lubbock: driest year ever with 5.86 inches of rainfall (old record was 8.73 inches in 1917)

Amarillo: driest year ever with 7.0 inches of rainfall (old record was 9.56 inches in 1970)

Victoria: 2nd driest year ever with 13.08 inches of rainfall (11.15 inches in 1917 is the all-time record)

Corpus Christi: 2nd driest year ever with 12.06 inches of rainfall (5.38 inches in 1917 is the all-time record)

Beaumont: 2nd driest year ever with 31.0 inches of rainfall (30.8 inches in 1954 is the all-time record, only missed that record by .2 of an inch)

To place this in even greater context:

The 7.0 inches of rainfall at Amarillo is less than the 9.1 inches seen in Tehran, Iran. The 5.86 inches at Lubbock is only an inch above Khartoum Sudan (4.8 inches). The period from October 1, 2010 to October 1, 2011 recorded a state average rainfall of about 11 inches or 16 inches below normal and less than that of Morocco and Tunisia!

The rainfall amounts over SE and E TX in 2011 were similar to what one would expect over the corridor from San Angelo to Midland. Effectively the climate of western TX was placed over what is typically a wet eastern TX resulting in severe impacts to water supply and vegetation. Additionally in deep eastern TX, 2012 starts the 3rd year of drought conditions…a longer term drought compared to locations along the coastal bend and central TX which moved into drought conditions during the spring of 2011 (12-15 months). Most of east TX was already running 15-25 inch rainfall deficits at the end of 2010 when most other locations were just starting to enter very dry conditions.

Rainfall Departures from January 1, 2010 – January 31, 2012:

Anahuac: -40.82

Bellville: -36.53

Brenham: -35.91

College Station: -32.83

Columbus: -29.59

Conroe: -38.68

Crockett: -26.23

Danevang: -21.99

Galveston: -46.65

Freeport: -47.61

Houston Hobby: -33.97

Houston IAH: -30.56

Huntsville: -49.49

Katy: -26.38

Livingston: -46.58

Madisonville: -41.32

Matagorda: -16.79

Palacios: -18.30

Somerville: -30.07

Tomball: -54.36

Beaumont: -36.14

Lake Charles: -34.48

October 1, 2019 to Feb 9, 2012 Rainfall Deficits:

Corpus Christi: -23.87

Victoria: -34.92

Laredo: -19.66

Water Supply:

Recent rains over N and E TX have lead to significant run-off into area lakes and rivers especially the Trinity River. Lake Livingston reached full pool capacity in Jan and then exceeded its capacity in early Feb requiring flood gate operations to maintain a steady pool near its conservation level. Lake Houston has also returned to 100% capacity due to the draw down from Lake Conroe ordered by the City of Houston last fall and the return of rains this winter. However, other water supply lakes remain very low with capacities running less than 60% and less than 40% across central TX. Statewide conservation storage is at 67% up from 59% at the end of summer 2011 and up from 62% on 1/15/2012…so some decent gains have been made in the last few weeks, but mainly only in the eastern part of the state. Some lakes remain completely dry in the western part of the state.

Lake Level departures from normal pool and % capacity of Feb 6, 2012:

Lake Conroe: -6.65 (72%)

Lake Houston: 0.00 (100%)

Lake Livingston: +1.30 (+100%)

Lake Somerville: -7.16 (54%)

Lake Texana: -9.29 (54%)

Lake Buchanan: -30.26 (40%)

Lake Travis: -53.99 (35%)

Lake Georgetown: -16.15 (53%)

Toledo Bend: -7.87 (71%)

Sam Rayburn: -9.55 (67%)

Note:

Lake Conroe reached a new record low pool elevation of 192.2 feet on 12/1/11 and has since recovered to around 194.0 feet

Sam Rayburn Reservoir tied its historical low of 150.75 feet on 11/20/11, and has recovered to 155.65 ft

Toledo Bend reached a new record low pool elevation of 159.57 feet on 11/19/11 surpassing its previous record of 161.5 feet in 10/2006, and has recovered to 164.64 ft.

On the Colorado River Basin which contains the highland lakes chain. A total of 127,699 acre-feet of inflow went into the lakes during 2011. In a normal year 1.25 million acre feet of inflow would go into those lakes…so around 10% of their yearly inflow occurred in 2011. Of the top 7 lowest monthly inflows into the Highland Lakes, 4 were established in 2011, the other 3 were held in the drought of the 1950’s including the top 1 and 2 lowest inflows. Note: 1 acre foot = 325,000 gallons of water. As of Feb 1, 2012 the combined storage of the highland lakes was 38% (historical low is 31% on 9/9/1952). LCRA projections show the highlands lakes falling to between 36-37% of capacity by March 1, 2012 and 25-31% of capacity by August 1, 2012 if the current rainfall patterns hold. This will push the lakes to near the drought of record of the 1950’s and trigger water use cuts by 20% for both municipal and industrial customers.

In early November 2011, 1000 out of the state’s 4700 public water systems had imposed voluntary or mandatory restrictions, 55 prohibited all outside watering and 23 were within 180 days of running out of water completely.

Fire Weather:

Luckily, frequent wetting rains have allowed fine fuels (winter grasses) to green and have prevented any major outbreaks of wildfires. Spring green up in 2012 should be much more robust than in 2011 due to the rainfall over the past 3 months allowing vigorous early growth of grasses and shrubs which did not happen in 2011. Lack of harsh winter cold is also allowing an early green up compared to the past 2 years. Burn bans remain in effect for 103 Texas counties across parts of west TX, SW TX, and the panhandle, but the fire weather threat remains low. KBDI is at or below 200 for nearly all of the counties in SE TX except for Jackson County which has values between 400-600. A KDBI of 0 is saturated conditions and 800 is the top 8 inches of soil is completely devoid of water.

A total of 4.1 million acres burned across TX in 2011 making it by far the worst wildfire year ever in state history. This acreage burned equals the land area of Rhode Island, Connecticut, Delaware, and DC combined. 2862 homes were lost (1939 over the Labor weekend alone) along with 2700 other structures such as out buildings and barns. Some other stats:

In State Response (Mutual Aid System):

207 fire departments

1,274 firefighters

329 fire engines

Out of State Response:

16,410 personnel from all 50 states and Puerto Rico deployed to TX

239 dozers used to cut fire lines

954 fire engines used

246 aircraft used (16,912 flight hours logged)

28 million gallons of water dropped

5.9 million gallons of fire retardant dropped

54,192 total aircraft drops.

Tree Mortality

One of the most striking impacts of the drought has been the tremendous loss of trees across the state, but especially in east Texas and around the Houston area. The Texas Forest Service estimates that between 100-500 million trees (2-10% of the entire state canopy coverage) have died due to the drought and another 4 million were killed by wildfire (1.5 million in the Bastrop fire alone). This estimate does not include tree mortality in urban areas and it is estimated that those numbers could be as high as an additional 50-150 million trees. Loblolly Pines and Water Oaks have suffered greatly in eastern TX especially in areas where water typically ponds that dried out during the drought (river bottoms, marsh areas, ect). Many trees went into dormancy in the late summer last year to conserve what little water was still available and the big question is did they survive, this will be determined once the spring green up begins.

There were 3 extensive areas of very heavy loss:

The western fringe corridor of the Piney Woods (from Walker and Madison Counties southward to Waller and Harris Counties including Grimes and Montgomery counties). Heavy losses of pines in this region with some stands of trees in Montgomery and Grimes Counties showing 90-100% mortality.

The second area was across Lee, Caldwell and Bastrop counties where widespread mortality of cedar and post Oak trees have been noted along with heavy losses on pines in Bastrop County both pre and post fire conditions.

The third area was along I-10 in Sutton and Crockett Counties where near total losses of ash juniper were noted.

Memorial Park:

The combination of the extremely hot and dry summer and urban development around Memorial Park likely led to the staggering losses. It appears that at least 90% of the park’s canopy cover died with the City of Houston removing a total of 17,500 trees. Many of the trees were 100+ years old and lived through the droughts of the 1910’s and 1950’s, but were unable to survive the current drought. A total of 200,000 cubic yards of tree debris has been removed from Memorial Park.

The City also estimated that 80% of the pines in MacGregor Park died.

Centerpoint has removed 19,000 dead trees from their Right of Way at a cost of 5.1 million dollars.

Of the 225 school districts in the region, an estimated 225,000 trees have died on their property or a mortality rate of about 50%.

Even with the recent rains, deep rooted trees continue to suffer in areas where the drought has persisted the longest. Even when the drought ends, tree loss will continue due to the added stress of the dryness and the vulnerability of the trees to pests and disease. Additional updates will be available after the spring green up and this summer from the Texas Forest Service as aircraft will be used to survey the losses.

Ag Impacts:

Lack of fresh water supplies and poor vegetation for grazing have resulted in one of the largest cattle reductions ever in the state of Texas. Productions herds are down 600,000 from this time last year and is the lowest in the state since 1961. In addition, the body condition of cattle has deteriorated from poor nutrition and the calving season has progressed. Due to the drought it is estimated that consumer prices have increased 3.5-4.5% with beef being the largest increase at 8-9% along with timber (8%). Hay remains in short supply across much of the state and continues to sell at extremely high prices of 150 dollars per round bale to 13-20 dollars per square bale.

A record 5.2 billion dollars in losses have occurred across the state with an estimated additional indirect losses of 3.5 billion with total losses likely in the 8-11 billion dollars and this is from the fall of 2011.

Outlook:

Some good news appears in the longer range modeling showing a gradual weakening of the La Nina condition in the central Pacific. Even with the current La Nina rainfall patterns across eastern TX have been near to above normal since last November leading to hope that more normal spring rainfall will continue into 2012. Areas across south, west and central TX continue to experience below normal rainfall. While CPC maps for the next 1-3 months continue the trend of below normal rainfall through the spring, it is clear that the upper level pattern thus far this winter has favored more rainfall production than in 2011. Of greater importance is the wetting of the soil and keeping it wet into the warmer months to prevent the strong feedback processes of a dry ground against the lower air mass which helps build and intensify high pressure over the area killing chances for the more typical summer rains especially along the coast. If you are going to break a drought of this magnitude, this is one way to do it without a tropical system…frequent and consistent storm systems with widespread rains.

With that said, will favor the wetter side of things…near to above normal rainfall continuing into the spring for E and SE TX, with near or below normal rainfall over the central, western and southern parts of the state, but not as severe as in 2011. Spring convective events may bring more opportunity of some big totals in short periods of time given the lack of cold events this year over the Gulf and warm water temperatures able to supply greater moisture into the region. Above average temperatures will also continue in phase with the La Nina condition and the active southern jet helping to keep what arctic air there is in Canada well north of TX.

[Ed Lizard]

Euro 18Z skew-T similar to GFS really, more a hail threat than a tornado thread, but I think all modes would be possible.

SREFS hold out the possibility.

Edit to add- that tiny little blue area where all the SREFs have a SigTor greater than 1, that would be Steve's neighborhood if I read that correctly.

[#NoPoles]

every time i read about tree mortality my heart breaks...thanks for sharing those e-mails from Jeff...haunting to realize that some of the mortality trees were over 100yrs old- more than a century of weather, but this past year was just so anomalous they couldn't survive...

hey Srain,

could you forward me that e-mail...i have some friends in the MA Dept of Conservation and Rec program in the forestry division who would be astounded by the tree mortality...

[email protected]

[Srain]

The overnight models have come into much better agreement with Friday/Saturday time frame and it now appears a wide spread flood potential exists and the threat of severe storms also increases. The guidance has shifted the very heavy rainfall potential further inland and an area wide Flash Flood Watch may be needed for the first time since September 2010. 2-4 inches of rain appear possible across the entire region with some possible 5-6+ inch amounts not out of the question should slow moving severe storms with training develop. The exact focus of where the heavy rainfall cannot be known at this time, but with a slow moving Coastal Low and a potent upper level trough/low trekking E from old Mexico along or just N of the I-10 corridor areas from Central and SE TX appear to be the bulls eye for significant weather and extremely heavy rainfall. Our air mass is very moist and primed for such an event and I urge everyone to follow the forecasts and updates closely the next 24 hours as severe weather chances may be introduced and Flash Flood Watches may be hoisted across our entire region.

[Srain]

Morning e-mail from Jeff:

Heavy to excessive rainfall becoming likely over the region Friday-Saturday

Flash Flood Watches may be required

Very weak cool front trying to limp through the area this morning with dense fog south and east of the boundary. Strong sub-tropical jet stream aloft riding nearly parallel to this boundary is already helping to set off an area of widespread thunderstorms over S TX and the adjacent western Gulf waters. Moisture will be on a rapid increase today as ESE to SE winds above the surface begin to bring Gulf moisture back inland over the frontal slope. TX Tech meso model breaks out showers/thunderstorms across the counties counties by this evening in a region of enhanced lift from an approaching upper air disturbance and increasing isentropic lift over the coastal waters frontal boundary.

Will likely see a break in the action early Friday before the onset of the main event Friday afternoon-Saturday morning. Strong upper level trough over S CA this morning will dig SE into MX and then eject across TX early Saturday. This system will force a western Gulf of Mexico surface low with strong isentropic upglide over much of the southern half of TX by midday Friday. Expect widespread rains to quickly develop and spread NE during the day on Friday. NW Gulf surface boundary begins to back northward in response to NW Gulf surface low formation and this will add a surface boundary into the mix to help focus training of heavy rainfall. Current thinking is that this boundary will not move very far inland if at all and the threat for the really big totals may be out over the Gulf water however should this boundary move further north than expected, rainfall totals will need to be raised and the flash flood threat will be even higher. Even with the surface boundary remaining near the coast/offshore, there will be very strong lift coming to bear across the region along with the 850mb boundary in the region and both of these will favor some form of heavy rainfall inland. Could also see some strong elevated thunderstorms Friday night with the main threat being hail. System should clear the area by Saturday evening with another 24-36 hour break before the next system arrives Monday-Tuesday.

Rainfall Amounts/Hydro:

Upstream look at PW values shows a deep pool of 1.6-1.7 inch values over deep S TX into N MX and this moisture will rapidly spread northward over the next 24 hours. These moisture levels will be at or above the 200% levels for this time of year and when combined with some kind of stalled or slow moving boundary (surface front or 850mb front) really raises the warning flags when it comes to excessive rainfall and flooding. Additionally rainfall in the past 3 weeks has been well above average and frequent with little drying of the soil moisture between events. The top layers of soil are now saturated and will result in quicker run-off. Our northern counties are wetter than the coastal and SW counties as this has been where the greatest rainfall has been over the past month and this event looks to focus in the coastal areas.

Will go with widespread 1-3 inches of rainfall south of I-10 with isolated amounts of 4-5 inches possible especially under the strongest storms and where training develops. Locations most at risk for some of the heavier totals appear to be right along the coast northward to US 59 near/just north of the surface front and south of the 850mb front. North of I-10 totals will average .5-2.0 inches.

With grounds saturated or nearing saturation rainfall of this magnitude will result in large amounts of run-off. Significant rises on area creeks, bayous, and rivers will be likely if the rainfall forecast verify as forecasted.

HPC (Day 1-3 rainfall (QPF) Totals)

[Ed Lizard]

SREFs from 9Z were not mega-exciting for even elevated severe, setting the bar low, measureable precip, 500 J/KG MUCAPE and 30 knots deep layer shear, only about 20% of the members even did that.

The heaviest rains may occur South of where the rain fell yesterday, although my lawn was saturated yesterday morning.

EXCESSIVE RAINFALL DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD

158 PM EST THU FEB 16 2012

...VALID 18Z THU FEB 16 2012 - 00Z SAT FEB 18 2012...

...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...

...SOUTHERN TEXAS...

MODELS ARE COMING INTO AGREEMENT ON A MDT-HVY RAINFALL EVENT

ACROSS SRN TX TO ALONG THE GULF COAST INTO NRN FL THIS PERIOD.

DEEP MOISTURE OVERRUNNING A STALLED FRONTAL BNDRY IN COMBINATION

WITH WEAK MID LVL ENERGY MOVING THRU SWLY FLOW OUT AHEAD OF THE

LOW MOVING THRU NRN MEX ALONG WITH AN UPR JET COUPLET IS FORECAST

TO SUPPORT THE DEVELOPMENT OF MDT-HVY RAINS ACROSS PARTS OF THE

SRN TX PLAINS TO THE UPR GULF COAST TONIGHT INTO EARLY TOMORROW

MORNING. GFS/00Z ECMWF WERE IN FAIRLY GOOD AGREEMENT...THE

BIGGEST DIFFERENCE BEING THE GFS WAS A LITTLE MORE BULLISH WITH

AMTS. GIVEN THE FORECAST AVAILABLE MOISTURE AND FAVORABLE

FORCING...WAS INCLINED TO LEAN TWD THE HEAVIER AMTS. WHILE THE

FORECAST AMTS ARE WELL BELOW FFG VALUES...THERE IS THE POTENTIAL

FOR HVY RAINS TO FALL ACROSS AREAS INUNDATED BY HVY RAINS

YESTERDAY. THIS IS ESP A CONCERN ACROSS SERN TX WHERE THE HEAVY

RAINS FALLING YESTERDAY FELL ACROSS A REGION IMPACTED BY MONTHS OF

DROUGHT AND QUICKLY BECOME RUN-OFF...CREATING NUMEROUS FLOODING

PROBLEMS.

PEREIRA

[Srain]

Afternoon e-mail from Jeff:

Flash Flood Watch will be issued from midnight tonight through noon Friday.

Models progging a strong southern stream short wave to cross the area tonight into early Friday ahead of a larger upper level trough/low on Friday night/Saturday. The result is the rapid formation of widespread rainfall and thunderstorm tonight/early Friday across the region as mid level flow backs to the ESE and pumps tremendous Gulf moisture over the top of the stalled front off the coast. Concern is growing that training of excessive rainfall on top of saturated grounds may lead to flooding problems. Additionally, moisture levels will increase to 200% of normal which raises several red flags when dealing with either slow moving or training convection.

Widespread rainfall amounts of .5 to 1.5 inches appear likely by noon of Friday with some isolated totals upwards of 2-3 inches. Flash Flood Guidance for much of the region in the 3 hour time period is on the order of 2.5-3.5 inches with 1 hour guidance of 2.25 to 2.5 inches. Exceedance of these values for their time periods will generate excessive amounts of run-off and likely cause flooding.

Significant rises on area creeks, bayous, and rivers is becoming increasing likely with the forecast rainfall amounts.

Additional heavy rainfall is likely Friday night into Saturday which will only aggravate any ongoing run-off/flooding problems from tonight into Friday morning. May need to bump up total storm rainfall amounts as it is starting to appear the higher end totals may be more in line with what happens.

[Srain]

Morning e-mail from Jeff:

Flash Flood Watch extended until noon Saturday.

Significant rainfall event likely tonight-Saturday for much of SE TX with flooding possible.

Discussion:

Thus far the models have not handled the overnight short wave very well with almost no rainfall at all along the TX coast. Short wave was modeled too far southward and has ejected out of MX toward NC TX with widespread mainly light to moderate rainfall. Surface frontal boundary currently extends from near South Padre Island to off the coast of Matagorda Bay and then ENE toward southern Louisiana. Air mass over the western Gulf shows dewpoints in the 66-72 degree range with PWS of 1.5-1.6 inches. Thus far the moisture transport northward has been rather unimpressive as PWS over SE TX have only increased to just over 1.0 inch.

This afternoon:

Powerful upper level trough/storm digging SE into northern MX will begin to spread strong upper level lift across much of TX from SW to NE. At the surface, low pressure will develop on the offshore frontal boundary and begin the NE track up the coast. Latest model runs are more northward with this low and this raises the risk of the downstream warm front over the NW Gulf moving further inland. Expect showers to start to develop and expand northward from late morning through the afternoon hours as upglide of moisture over the frontal slope increases

Tonight-midday Saturday:

Widespread heavy rainfall likely with flooding.

By early this evening the surface low along the southern TX coast will be moving NE up the coast and then likely inland around Matagorda Bay after midnight. Warm front will surge northward toward the coast and likely inland to US 59 overnight. Strong lift both at the surface from the warm front and surface low combined with a splitting jet stream structure aloft as the upper trough moves into SW TX points to rapid development of bands of intense thunderstorms. While the meso models are more keen on a couple of bands of excessive rainfall, the global models show more of a larger area of heavy rain…neither is likely correct nor wrong with this kind of set up. Expect numerous thunderstorms to rapidly develop from the coastal bend into SE TX starting late this evening and then continuing overnight into Saturday morning. Feel the warm front will move inland due to the surface low being displaced slightly further north. This really places the counties along US 59 under the gun for the greatest rainfall and strongest storms.

Rainfall/Flooding:

Moisture levels are progged to reach 200% above normal and a look upstream over the western Gulf does show such values out there. Expect the formation of a 30-40kt low level jet by afternoon today to help advect the western Gulf moisture into place by this evening. Factors will be in place tonight into Saturday for a flash flood setup across the region. Air mass will likely become almost tropical like near and south of the warm front overnight with soundings showing a nearly saturated air column…leading to efficient rainfall production in thunderstorms. Thunderstorms will be capable of some very intense short term rainfall rates of 2-3 inches per hour which can get locations in to trouble very quickly. With a slow moving warm front in the region, this will help to focus and possibly train these high rainfall rate thunderstorms along a boundary greatly increasing the flash flood threat near the warm front. Current thinking is that the warm front will move inland along a line from Victoria to Wharton to Katy to Cleveland (near of just north of the US 59 corridor). Widespread rainfall amounts of 1-3 inches is likely with isolated amounts of 3-5 inches possible. Bands of training thunderstorms will quickly deliver excessive rainfall in a very short period of time overwhelming primary drainage systems. Significant street flooding is likely along with rises on area creeks, bayous, and rivers due to the already saturated grounds in place.

Severe Threat:

With the warm front looking more likely to move inland, this does increase the severe weather threat along and south of this boundary and then ahead of the cold front as the surface low moves across the area. While shear is favorable, instability is generally lacking, but there is some lurking out over the western Gulf. Meso models have been hinting at bowing line segments near the cold front across the coastal areas Saturday morning and also a fair amount of development ahead of the main line which could pose a weak tornado threat given the favorable shear profiles that will be in place. SPC does not have SE TX in a slight risk (see graphic below). Feel an upgrade to a slight risk for areas south of US 59 may be needed today. Main severe threat appears to be wind damage and large hail with an isolated tornado threat.

Midday Saturday-Saturday night:

Surface low moves into Louisiana with thunderstorms exiting to the east. Main upper trough will move over our northern counties and may produce a period of wrap around rainfall into late Saturday afternoon or evening north of I-10. Clearing and cooler Sunday as surface high moves into the area behind the cold front.

Extended:

Another storm system approaches the area Monday-Tuesday, but moisture looks limited so likely only a few showers. Another more potent looking system may be on tap for the middle to end of next week as this highly active pattern continues.

Day 1 Severe Weather Outlook:

[DoctorMu]

A Damper on the Dampness?

000

FXUS64 KHGX 171555

AFDHGX

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX

955 AM CST FRI FEB 17 2012

.UPDATE...

SEE MORNING UPDATE.

&&

.DISCUSSION...

THINGS NOT GOING TO PLAN THIS MORNING. LAST NIGHT`S S/WV WENT WELL

NORTH OF THE REGION TAKING MOST OF THE RAIN WELL NORTH OF THE REGION.

850 MB MOISTURE IS STILL LACKING AND WATER VAPOR IMAGERY DOES NOT

SHOW ANY S/WV`S MOVING TOWARD THE REGION. OTHER THAN WEAK WARM AIR

ADVECTION...CAN`T REALLY FIND ANY OTHER LIFTING MECHANISM SO HAVE

DECIDED TO LOWER POPS AND DELAY THE FLOOD WATCH TO 00Z. THE 12Z

NAM12 IS SHIFTING MOST OF THE PRECIP NORTH OF THE REGION OVERNIGHT

AND SATURDAY. AFTER LAST NIGHTS FORECAST...CONFIDENCE IS SOMEWHAT

LACKING. NEW ZONES OUT BY 1030 AM.

[DoctorMu]

ULL still spinning in N Mexico and we have the conveyor belt in place when they meet

http://www.goes.noaa.gov/GSSLOOPS/ecwv.html

[baroclinic_instability]

ULL still spinning in N Mexico and we have the conveyor belt in place when they meet

http://www.goes.noaa...LOOPS/ecwv.html

Another great drought buster for portions of TX. Guidance differs on how quickly the deformation band sets on as the upper low deepens Saturday afternoon, but I would bet on a stronger deform band simiar to ECMWF and NAM across portions of N Texas.

[DoctorMu]

Yep - Major drought-busting wetness from midnight to noontime. On and off showers in CLL this afternoon. A warmfront is going to cause some lift. Flash Flooding is a real possibility, but should come during lighter traffic hours here. HOU Sat am could be hazardous driving with saturated ground.

000

FXUS64 KHGX 172349

AFDHGX

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX

549 PM CST FRI FEB 17 2012

.AVIATION...

MESSY WEATHER TONIGHT AND MUCH OF SATURDAY. AREA OF MOSTLY LIGHT

RAIN MOVING THROUGH SOUTHEAST TEXAS CURRENTLY. EXPECT THIS TO MOVE

EAST OF THE REGION BEFORE 04Z WITH VCSH CONTINUING. AS THE WARM

FRONT LIFTS NORTH EXPECT PCPN TO INCREASE WITH TWO AREAS OF PCPN.

ONE AREA NEAR THE COAST AND ANOTHER AREA FURTHER TO NORTH IMPACT

KCLL AND KUTS. THIS PCPN WILL DEVELOP AFTER 06Z AND WILL CONTAIN

SOME TSRA AND WIDESPREAD RAIN. CIGS FOR THE MOST PART WILL BE MVFR

WITH IFR IN AREAS OF PCPN. FRONTAL SYSTEM WILL MOVE OFF THE TX

COAST BEFORE 19/00Z BUT RAP AROUND CLOUDS AND SOME PCPN WILL STILL

PERSIST IN SOME AREAS SO LOW CLOUDS WILL BE SLOW TO CLEAR OUT SAT

AFTERNOON. WINDS WILL BECOME NORTHWEST BEHIND THE FRONT WITH GUSTS

TO 22KNOTS MAINLY AFTER 22Z.

&&

.PREV DISCUSSION... /ISSUED 314 PM CST FRI FEB 17 2012/

DISCUSSION...

AT 20Z...A WARM FRONT EXTENDED FROM CRP TO NEAR PSX AND THEN EAST

ACROSS THE GULF. THE FRONT HAS BEEN MOVING SLOWLY NORTH AND WILL

LIKELY SERVE AS THE FOCUS FOR HEAVY RAIN OVERNIGHT. SHRA/TSRA ARE

BEGINNING TO DEVELOP AND THE CONVECTION WILL INCREASE IN COVERAGE

AND INTENSITY AS THE UPPER LOW OVER NORTHERN MEXICO SHIFTS EAST

TONIGHT AND SATURDAY. SURFACE LOW PRESSURE WILL DEVELOP OVER

NORTHERN MEXICO AND THIS FEATURE WILL MOVE UP THE COAST OVERNIGHT.

STRONG LOW LEVEL CONVERGENCE WILL DEVELOP TONIGHT AND HEAVY RAIN

IS EXPECTED TO FOCUS ALONG AND NORTH OF THE WARM FRONT IN THE

CONVERGENT ZONE. PW VALUES ARE PROGGED TO INCREASE TO 1.7 INCHES

BY 12Z SATURDAY. UPPER LEVEL WINDS WILL BECOME STRONGLY DIVERGENT

BETWEEN 06-12Z AS THE UPPER LOW APPROACHES WITH SOUTHEAST TEXAS

LYING IN A WELL DEFINED JET COUPLET. FURTHER NORTH...ANOTHER AXIS

OF HEAVY RAIN WILL LIKELY DEVELOP ALONG THE TRACK OF THE 850 MB

LOW. WRAP AROUND MOISTURE WILL KEEP RAIN OVER THE NORTHERN ZONES

WHILE DRY SLOTTING FURTHER SOUTH SHOULD ALLOW THE RAIN TO END IN

THE EARLY AFTERNOON. AT THIS TIME...FEEL STRATIFORM RAIN WITH

EMBEDDED THUNDER WILL DEVELOP OVER THE NORTH...AND NUMEROUS

SHOWERS AND THUNDERSTORMS WITH CONVECTIVE BURSTS OF HEAVIER RAIN

WILL PREVAIL SOUTH. CURRENTLY FEEL 1 TO 2 INCHES OF RAIN WILL FALL

OVER THE NORTH AND 2 TO 4 INCHES WILL FALL ALONG AND SOUTH OF U.S.

HIGHWAY 59 TOWARD THE COAST. WILL MAINTAIN THE FLOOD WATCH THROUGH

18Z SATURDAY. HPC HAS OUTLOOKED PARTS OF THE UPPER TEXAS COAST IN

SLIGHT RISK FOR EXCESSIVE RAINFALL. IF WEDNESDAYS RAIN EVENT IS

ANY INDICATION...IT WILL ONLY TAKE 2.0 TO 2.5 INCHES OF RAIN IN 3

HOURS TO PRODUCE RUN-OFF AND FLOODING. STORMS CLOSE TO THE COAST

WILL ALSO HAVE THE POTENTIAL TO PRODUCE SOME GUSTY WINDS BUT FEEL

THE HEAVY RAIN IS THE PRIMARY SEVERE WEATHER HAZARD.

CONDITIONS WILL DRY OUT SUN/MON BEFORE ANOTHER MID LEVEL TROUGH

SWINGS THROUGH THE REGION ON TUESDAY/WEDNESDAY. MOISTURE LOOKS

RATHER LIMITED AT THIS TIME BUT WILL CARRY SLIGHT CHANCE JUST IN

CASE. ECMWF AND GFS DIFFER TOWARD THE END OF NEXT WEEK. TOSSED IN

20S FOR NEXT SATURDAY IN CASE THE ECMWF IDEA OF BRINGING ANOTHER

TROUGH ACROSS PANS OUT. 43

[bubba hotep]

Another great drought buster for portions of TX. Guidance differs on how quickly the deformation band sets on as the upper low deepens Saturday afternoon, but I would bet on a stronger deform band simiar to ECMWF and NAM across portions of N Texas.

Interesting, I was thinking we might see more rain up here but that was just a gut feeling. You've been doing great work over in the mid-Atlantic thread.

[Ed Lizard]

[My Weather Today]

The 02/18 GFS 00Z run appears to be initiating too much precipitation just south of the Mid & Upper Texas coast line for this time range. Current radars are showing most of the rain and thunderstorms to be inland right now.

[Srain]

From Jeff:

Severe line of thunderstorms capable of large hail and winds to 60mph moving rapidly E across the area. Warning is in effect for this line for Montgomery, Harris, Waller, Austin, and northern Fort Bend Counties.

Surface warm front has moved inland to along a line from Victoria to Sugar Land to just south of Hobby Airport with a surface low noted just west of Victoria. Line of strong storms with very heavy rainfall (1-2 inches per hour) will sweep across much of the area in the next 1-3 hours. Watching the southern end of the line very closely near and SW of Victoria to near Wharton as radar trends suggest the line is slowing and may start training greatly raising the flood threat along the US 59 corridor. Storms may intensify as they cross over the warm front into the warm sector in the next hour or so.

[Srain]

MESOSCALE DISCUSSION 0123

NWS STORM PREDICTION CENTER NORMAN OK

0435 AM CST SAT FEB 18 2012

AREAS AFFECTED...SERN TX

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 181035Z - 181130Z

STORMS WILL CONTINUE TO AFFECT SERN TX AND EVENTUALLY SWRN LA LATER

THIS MORNING. A FEW STRONG TO SEVERE WIND GUSTS MAY OCCUR.

STORMS HAVE CONSOLIDATED ACROSS SERN TX ON SURGING OUTFLOW/COLD

FRONT COMPOSITE BOUNDARY. AHEAD OF THIS LINE...WARM ADVECTION

CONVECTION WAS SHIFTING NWD OVER SERN TX INTO WRN LA. THIS

CONVECTION IS A GOOD PROXY FOR THE WARM FRONT...WHICH MAY BE

SLIGHTLY ELEVATED. SURFACE OBSERVATIONS SHOW TEMPERATURES IN THE 60S

S OF THIS BOUNDARY...WITH SIMILAR DEWPOINTS. FORECAST SOUNDINGS

INDICATE THAT DESPITE COOL TEMPERATURES...LITTLE CAPPING

EXISTS...ESPECIALLY IN VICINITY OF THE FORCED LINE OF STORMS.

FURTHER...THERE MAY BE POTENTIAL FOR DOWNWARD MOMENTUM TRANSFER AND

WITH LONG HODOGRAPHS IN PLACE...THIS ACTIVITY MAY PERSIST FOR

SEVERAL HOURS. GIVEN THE MARGINAL BOUNDARY LAYER THOUGH...SEVERE

THREAT IS NOT EXPECTED TO BE WIDESPREAD.

OTHER CELLS WERE DEVELOPING FARTHER S AS WELL ALONG THE COLD FRONT.

CAPPING IS A PROBLEM FROM CRP TO BRO...BUT IT IS POSSIBLE THAT DEEP

FORCING ALONG THE FRONT COULD EVENTUALLY OVERCOME THE

INVERSION...WITH A FEW STORMS DEVELOPING NEAR THE COAST BEFORE

QUICKLY MOVING OFFSHORE. THESE STORMS MAY PRODUCE HAIL IF THEY

REMAIN CELLULAR.

..JEWELL.. 02/18/2012

ATTN...WFO...LCH...HGX...CRP...EWX...BRO...

[Srain]

BULLETIN - IMMEDIATE BROADCAST REQUESTED
  SEVERE THUNDERSTORM WATCH OUTLINE UPDATE FOR WS 27
  NWS STORM PREDICTION CENTER NORMAN OK
  450 AM CST SAT FEB 18 2012

  SEVERE THUNDERSTORM WATCH 27 IS IN EFFECT UNTIL 900 AM CST
  FOR THE FOLLOWING LOCATIONS

  LAC019-023-181500-
  /O.NEW.KWNS.SV.A.0027.120218T1050Z-120218T1500Z/

  LA
  .    LOUISIANA PARISHES INCLUDED ARE

  CALCASIEU		    CAMERON			


  TXC039-071-157-167-199-201-239-245-291-321-339-361-407-481-
  181500-
  /O.NEW.KWNS.SV.A.0027.120218T1050Z-120218T1500Z/

  TX
  .    TEXAS COUNTIES INCLUDED ARE

  BRAZORIA			 CHAMBERS		    FORT BEND		  
  GALVESTON		    HARDIN			  HARRIS			 
  JACKSON			  JEFFERSON		   LIBERTY			
  MATAGORDA		    MONTGOMERY		  ORANGE			 
  SAN JACINTO		  WHARTON			


  GMZ330-335-350-355-430-432-450-181500-
  /O.NEW.KWNS.SV.A.0027.120218T1050Z-120218T1500Z/

  CW

  .    ADJACENT COASTAL WATERS INCLUDED ARE

  MATAGORDA BAY

  GALVESTON BAY

  COASTAL WATERS FROM FREEPORT TO MATAGORDA SHIP CHANNEL TX OUT 20
  NM

  COASTAL WATERS FROM HIGH ISLAND TO FREEPORT TX OUT 20 NM

  SABINE LAKE

  CALCASIEU LAKE

  COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM

  ATTN...WFO...LCH...HGX...

[Ginx snewx]

congrats Steve

[Srain]

congrats Steve

Thanks Steve, in think...

[Ginx snewx]

Thanks Steve, in think...

Just happy you guys are out of the drought stuff.

[Srain]

E-mail update from Jeff:

Excessive rainfall and flooding developing over the region this morning.

Flash Flood Warning is in effect until 930am for Fort Bend, Harris, and Brazoria Counties

Powerful upper level low near Big Bend continues to supply ample lift over SE TX resulting in near continuous development of thunderstorms around Victoria which then train NE across the area. Rainfall in the last 24 hours has averaged 1-2 inches over much of the area with totals nearing 3-3.5 inches over eastern Fort Bend and SW Harris County. There have been numerous reports of flooding this morning mainly limited to roads, however watersheds are running very high and additional rainfall will likely cause some channels to exceed their banks.

Currently these 3 watersheds in Harris County are running very high:

Lower South Madye Creek

Cypress Creek

Carpenters Bayou

Radar continues to show thunderstorms forming in the favorable region of lift on the east side of the upper low from the coastal bend region into SE TX. Additional rainfall amounts of 1-2 inches will be possible which will only worsen ongoing flooding issues.

[Srain]

MESOSCALE DISCUSSION 0125

NWS STORM PREDICTION CENTER NORMAN OK

0931 AM CST SAT FEB 18 2012

AREAS AFFECTED...SRN LA...FAR SRN MS

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 181531Z - 181630Z

ELEVATED TSTMS SHOULD TRANSITION TO BECOMING SURFACE-BASED THROUGH

THE DAY...WITH A CORRESPONDING INCREASE IN DAMAGING WIND AND

EVENTUALLY TORNADO POTENTIAL...ESPECIALLY ACROSS SERN LA THIS

AFTERNOON. A TORNADO WATCH WILL LIKELY BE ISSUED BY 1630Z.

BOWING STRUCTURE HAS BECOME MORE PROMINENT WITH LEAD SQUALL LINE

ACROSS ST LANDRY TO CAMERON PARISHES AS OF 1525Z. ALTHOUGH MODIFIED

12Z LCH RAOB SUGGESTS THIS BOW IS ELEVATED WITH MINIMAL

SURFACE-BASED INSTABILITY...DOWNSTREAM AIR MASS CONTINUES TO

WARM/MOISTEN ACROSS SERN LA. 15Z SURFACE ANALYSIS INDICATES WARM

FRONT APPEARS TO HAVE SURGED NWD ACROSS SRN LA...NOW DRAPED EWD

TOWARDS LK PONTCHARTRAIN. ALTHOUGH THE RICHER MARITIME AIR MASS

REMAINS ALONG/JUST OFF THE SRN LA COAST...MODIFIED RUC/NAM SOUNDINGS

SUGGEST 64-65 F SURFACE DEW POINTS WILL BE SUFFICIENT FOR

SURFACE-BASED PARCELS. GIVEN 0-1 KM SHEAR AOA 30 KT...AN INCREASING

RISK FOR DAMAGING WINDS AND TORNADOES IS ANTICIPATED.

..GRAMS.. 02/18/2012

ATTN...WFO...MOB...LIX...LCH...