Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 4

[bubba hotep]

Still rain in Forney. Snow should mix in here by 3 pm CST.

We are basically due north of Forney up in Collin County and we've got a nice mix flying but are still above freezing.

[Quixotic1]

all snow here in southern dallas. 34 though

[Terpeast]

We are basically due north of Forney up in Collin County and we've got a nice mix flying but are still above freezing.

Actually, it just started sleeting. Seeing a sleet / rain / (maybe)wet snow mix that's melting on contact. I was hoping the arctic air would beat the dry air coming from the SW... looks like it will.

[bubba hotep]

I'm going to call "all snow" here and 33. Temps have been crashing the last couple of hours and it should be magic time here soon

ETA: Turning White

[Terpeast]

Now I can say for sure that it is snowing. Still above freezing so it will be a while before it starts accumulating.

[bubba hotep]

Down to 32.5 and really starting to kick out there

ETA: This is legit. If I didn't now any better, I would think that I was back in Alexandria, VA and the coastal low was just starting to get cranked up

[Terpeast]

All snow and accumulating in grassy areas and rooftops and decks. close to an inch now. White Christmas!

[bubba hotep]

Below freezing! It is amazing how quickly things change once you pass that bench mark. Snow is really blowing around and winds are kicking up.

[Quixotic1]

2" here in southern dallas. bout to head back to frisco.

[bubba hotep]

2" here in southern dallas. bout to head back to frisco.

Be safe out there! Drinking some stouts and watching the snow up here in Collin County

[bubba hotep]

Some of the most impressive snow of the day now

[Terpeast]

Very close to 2 inches... don't think we quite made 2 inches in Forney, but that could be because of compacting. Saw some snow blowing around as well.

[Quixotic1]

Be safe out there! Drinking some stouts and watching the snow up here in Collin County

thanks! as an fyi ndt was shut down.

[bubba hotep]

Not too shabby

[Srain]

Morning e-mail from Jeff:

Progressive weather pattern over the southern US to continue.

Winds still coming down after the powerhouse wind event yesterday afternoon/evening with frequent gust to 40-50mph…for the second time in less than a week. Deep surface cyclone now moving into the OH Valley with skies clearing from WSW to ENE across SE TX under continued cold air advection pattern with temperatures near freezing and wind chills in the lower 20’s. Upstream air mass passing over the snow covered plains of N TX and OK will result in little modification today as solar energy goes into snow melt instead of warming the near surface air. With this in mind and NW winds continuing through much of the day, highs will only climb into the mid to upper 40’s under mainly sunny skies. Cold tonight as winds go nearly calm and skies remain clear…although could see some high level cirrus clouds pass over the region…but these rarely prevent cooling. Most areas will see lows in the 26-32 range except for the typical warmer spots (inside the Beltway and along the coast).

Coastal trough begins to take shape off the coastal bend early Thursday with a rapid increase in cloud cover as moisture is brought northward over top of the retreating cold surface dome. By afternoon isentropic lift may be enough to produce a few showers across the area. Highs will warm into the 50’s as winds turn more ESE on Thursday. Rain chances increase Thursday night into Friday ahead of the next powerful cold front. Surface trough will lift NE along the coast with light to moderate showers streaming northward out of the Gulf. Cold front will cross the region Friday afternoon with a line of showers and thunderstorms. Current thinking is that warm unstable air mass will remain out over the Gulf waters and the warm front will not move inland and this should negate a severe weather threat…however elevated instability may be enough to produce a few strong storms on the frontal boundary.

Once again windy behind this front, but not the kind of winds we saw yesterday. Should see NW 15-25mph Friday night under strong cold air advection. I am tempted to go a little colder than guidance for the weekend with the snow pack lingering to our north and fresh Canadian air pouring down the plains across this snow pack…however some degree of melting will occur between now and Friday night. Will stick with highs in the 50’s on Saturday under sunny skies and a light freeze similar to tonight on Sunday morning.

New Year’s Storm System:

Attention will quickly focus on another potential high impact storm system starting late Sunday and continuing through New Year’s Day. Model are having a tough time with this feature as with the Christmas Day event with the GFS more open and progressive versus the ECMWF and CMC more closed off and stronger. Given the current highly progressive flow across the US, will side toward the GFS, but the system may be somewhat slower than what this model shows. Anyhow the track of the core of the upper low/trough looks to be further south than the Christmas system which brings the threat for winter weather deeper into TX and suppresses the possible warm front closer to the coast. Parameters look to be coming together for another bout of severe weather across the area…possibly more focused deeper into the region than the past event yesterday. Still a ways off and things will no doubt change between now an early next week.

Christmas Day Storm Reports:

***Damage survey will be conducted today over Houston and Trinity Counties to determine tornado intensity and damage paths)***

Madisonville, Madison: numerous trees and roofs blown off along HWY 21 (possible tornado)

9 NW Crockett, Houston: tornado report by public near Houston County Lake

13 SE Crockett, Houston: tornado damage to a building and bank on 287. Large tornado recorded on cell phone relayed to broadcast media.

15 SE Crockett, Trinity: spotter reported a tornado on the ground moving across a pasture.

Lovelady, Houston: Lovelady fire chief report wind gust to 80mph

Tomball, Harris: *1 fatal* Non-Thunderstorm wind gust to 50mph resulted in numerous downed trees. Man was struck and killed by falling tree.

Cleveland, Liberty: Large Pine tree downed 8 miles SE of Cleveland (possible tornado)

Katy, Harris: Grass fire developed late in the afternoon along Katy Hockley Cut-off Rd and Clay Rd. 3 fire departments responded due to the strong winds. No homes were threatened

Corpus Christi, Live Oak: 200 acre wildfire burned 2 homes and 1 vehicle in the Hideaway Hills subdivision. Winds gusting to 50mph forced the evacuation of 90 residents as the fire spread rapidly. TX Forest service crews responded with local FD’s to bring the fire under control and saved over 50 homes

Dallas, Dallas: 2-4 inches of snow recorded across the metro area.

Plano: 3.0 inch snow

Tuesday Wind Gust:

BUSH IAH: 51

College Station: 54

Tomball: 46

Wharton: 45

Conroe: 49

Hobby Airport: 56

Brenham: 46

Bay City: 44

Galveston: 47

Lake Jackson: 46

Pearland: 51

Palacios: 53

Huntsville: 52

Bay City: 39

Victoria: 48

[Ed Lizard]

EF-3 destroyed the feed store in Houston county http://www.srh.noaa.gov/productview.php?pil=HGXPNSHGX736

NOUS44 KHGX 262219 CCA

PNSHGX

TXZ163-164-176>179-195>200-210>214-226-227-235>238-072300-

PUBLIC INFORMATION STATEMENT

NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX

415 PM CST WED DEC 26 2012

...PRELIMINARY STORM REPORT ON EF-3 TORNADO IN HOUSTON COUNTY...

NWS STORM SURVEY TEAM HAS CONFIRMED AT LEAST ONE TORNADO IN HOUSTON

COUNTY NEAR PENNINGTON. THE TORNADO WAS RATED AN EF-3 TORNADO WITH

NUMEROUS TREES DOWN AND SEVERAL BUILDINGS DAMAGED OR DESTROYED NEAR

THE TOWN OF PENNINGTON. THE TORNADO PATH WAS PARALLEL TO HIGHWAY

287 ABOUT 1 MILE NORTH OF PENNINGTON. MORE INFORMATION WILL BE

AVAILABLE AS THE TEAM CONTINUES TO COLLECT INFORMATION ON THIS

TORNADO AND POSSIBLY OTHER TORNADOES IN SOUTHEAST TEXAS.

NNNN

[bubba hotep]

Looks like the 18z GFS takes a pretty big step towards the Euro.

[Srain]

Morning e-mail from Jeff:

Active pattern in place and will continue for the next several days.

Most locations fell to and below freezing before midnight with IAH falling to 31. After midnight clouds rolled in from the SSW and winds increased from the ENE raising temperatures into the upper 30’s and low 40’s currently. Moisture return is in response to the next storm system which will move across TX on Friday. CRP radar shows light echoes already developing over the Gulf waters south of Matagorda Bay and this is likely the start of drizzle and light rain which will spread northward today. Meso scale short term models are in good agreement that light rain will move inland from the Gulf this afternoon as the low levels continue to moisten and moisture increases ahead of a warm front/coastal trough.

Upper level trough will swing quickly across the state on Friday with another strong cold front pushing across the area. Moisture return ahead of this front will be plentiful to produce a round of showers and thunderstorms on Friday along the boundary. Rainfall today through tonight will be mainly light with higher amounts expected on Friday as rainfall becomes slightly more convective in nature. Do not expect severe weather with this system, but a few strong storms will be possible east of I-45 where instability will be highest.

Strong cold air advection will onset behind the front on Friday with temperatures falling quickly into the 40’s after sunset under strong NW winds. Winds will be in the 15-20mph this time around instead of the 40-50mph we saw two days ago. Clear and cold conditions over the weekend with highs in the 50’s and lows near freezing.

New Year’s Storm System:

Main focus is quickly turning to a projected powerful storm system to affect the state from late Sunday through Wednesday of next week. GFS and CMC are the more progressive of the models showing an open trough passing across the state on Wednesday with most of the weather on Monday and Tuesday, while the ECMWF is much slower and cut off with the system and shows an extended period of cold wet weather through much of next week. Pattern of late has been highly progressive and the GFS has a good deal of support from its ensemble members, so will side with the faster models. Moisture begins to return from the western Gulf in earnest late Sunday and the combined effects of the moisture return and lift over a warm front south of the area will support light rain developing and spreading inland from the coastal bend area. Models are suggesting some really tropical type moisture pushes into the area late Monday with PWS values nearing record 2.0 inch levels for early January. Think this is likely overdone to some degree, but a lot of moisture looks to move into the area regardless so the threat for widespread rainfall…some heavy…will be possible starting Monday and continuing into Tuesday. Could see some severe weather also with a warm front over the region, but it is too early for specifics on that considering the event is still about 4-5 days away.

Note:

NWS survey teams investigated the tornado damage in Houston County from Christmas morning and determined the rating as EF-3 damage with estimated winds of 150mph, a path length of 7 miles and path width of 300 yards. The tornado completely destroyed two structures and heavily damaged others in the area. Most of the damage along the path was in the EF-1 and EF-2 range. The tornado was on the ground for roughly 10 minutes.

[Srain]

The 12Z Euro suggests the cold core upper low drops S of the Great Basin and lingers. A strong cold front pushes to Coastal Texas on January 1st and stalls. The upper low is still to our W over Northern Mexico and cold air funnels S as high pressure builds across the Central Plains and a Coastal low develops in the Lower/Middle/Upper Texas Coast and begins to slowly slide ENE late January 1st and 2nd. There appears to be a lot of over running precip developing across the Southern half of Texas into Louisiana as the 500mb low slowly begins to move E. Winter weather breaks out across the Big Bend and possibly W Central Texas late on the 2nd. The wave of low pressure continues to slide S of Louisiana on the 3rd with plenty of moisture at the 700mb level across Coastal Texas. The temp anomalies are very chilly from New Years Day continuing into the days following as the upper low very slowly moves across Texas into Louisiana by the end of the first week of January. It does appear that plentiful snow falls across New Mexico as well with the potent storm system suggested by the Euro. We will see how everything unfolds over the weekend and the short wave trough drops S off/near the California Coast. It should be noted that the forecast remains very uncertain at this range.

[My Weather Today]

URGENT - WINTER WEATHER MESSAGE

NATIONAL WEATHER SERVICE FORT WORTH TX

904 PM CST THU DEC 27 2012

...WINTER WEATHER ADVISORY IN EFFECT FROM 4 AM TO NOON CST

FRIDAY...

THE NATIONAL WEATHER SERVICE IN FORT WORTH HAS ISSUED A WINTER

WEATHER ADVISORY FOR FREEZING DRIZZLE...WHICH IS IN EFFECT FROM 4

AM TO NOON CST FRIDAY.

* TIMING...DRIZZLE IS EXPECTED TO BEGIN OVER THE ADVISORY AREA

WITH ABOVE FREEZING TEMPERATURES AFTER MIDNIGHT. AFTER 4 AM A

COLD FRONT IS EXPECTED TO MOVE INTO THE ADVISORY AREA...BRINGING

SURFACE TEMPERATURES BELOW FREEZING. DRIZZLE IS EXPECTED TO

CONTINUE WHILE TEMPERATURES SLOWLY DROP THROUGH EARLY FRIDAY

MORNING RESULTING IN FREEZING DRIZZLE. FREEZING DRIZZLE IS

EXPECTED TO DIMINISH BY LATE FRIDAY MORNING.

* MAIN IMPACT...FREEZING DRIZZLE WILL LEAVE A LIGHT GLAZE OF

ICE...PRIMARILY ON ELEVATED SURFACES AND ROADWAYS...SUCH AS

BRIDGES AND OVERPASSES. THIS LIGHT GLAZE OF ICE WILL MAKE FOR

VERY DANGEROUS DRIVING CONDITIONS.

* OTHER IMPACTS...DRIZZLE AND FREEZING DRIZZLE MAY REDUCE

VISIBILITIES BELOW ONE MILE AT TIMES THROUGH LATE FRIDAY

MORNING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY MEANS THAT PERIODS OF WINTER

PRECIPITATION MAY CAUSE TRAVEL DIFFICULTIES. BE PREPARED FOR

ICY SPOTS ON ELEVATED ROADWAYS AND PLAN ON SOME TRAVEL DELAYS.

[Srain]

Morning e-mail from Jeff:

Rain is pushing offshore and into Louisiana this morning as the coastal surface trough moves ENE away from SE TX.

Overnight rainfall totals averaged generally less than .50 of an inch over much of the area with higher amounts .50 to 1 inch mainly east of I-45. Fog and low clouds continue to cover the entire region ahead of another strong cold front currently entering C TX. This front will reach the coast by late afternoon bring gusty NW winds and falling temperatures along with clearing of the fog and clouds out of the area.

Cold tonight even with the wind staying gusty with lows in the 30-35 range across the area and highs on Saturday only in the low to mid 50’s under sunny skies. Light freeze most areas Sunday morning 29-32 with highs back into the upper 50’s.

Changes begin to take shape on Sunday afternoon as the next powerful storm system in this progressive split flow pattern enters into the SW US. Moisture will surge northward from S TX on Sunday as a warm front begins to advance northward. Expect a rapid influx of low clouds similar to yesterday with light rain and fog advancing northward ahead of the warm front on Sunday evening. Moisture values really ramp up Sunday night with very healthy PWS forecasted into the region by early Monday…nearing record levels for this time of year. Large scale lift will be increasing late Sunday into most of Monday as the upper trough advances eastward into the southern plains and surface low pressure develops along the warm front and moves up the coast. Still too early to determine if and/or how far inland the warm front may penetrate, but areas along this feature could have a severe weather threat. As suspected yesterday the more progressive GFS model was the correct line of thinking with this system as the ECMWF has trended in that direction. With the more progressive solution, expect widespread rains on Monday followed by a line of thunderstorms Monday night/early Tuesday. Some of the storms could be severe with damaging winds and tornadoes along with very heavy rainfall.

This leading short wave will force a strong cold front through the region on New Year’s Day, but the main upper trough looks to linger back SW of the area into N MX keeping a SW flow aloft over the surface cold dome…an overrunning pattern. Both the GFS and ECMWF generally agree with this thinking, but the ECMWF is more closed off with the main upper trough and colder compared to the GFS. Do not think clouds will clear out much behind the frontal passage early New Year’s Day and it is possible that a very cold rain could develop on Wednesday into Wednesday night. Will need to keep a close eye on low temperatures both Wednesday and Thursday mornings for our N and W counties as they will be nearing freezing with some chance of potential rain.

[bubba hotep]

Interesting discussion by FWD this afternoon:

.PREV DISCUSSION... /ISSUED 303 PM CST FRI DEC 28 2012/

THE UPPER LEVEL SHORTWAVE TROUGH THAT WAS RESPONSIBLE FOR THE FOG

AND DRIZZLE HAS MOVED EAST OF THE AREA. IN ITS WAKE...SURFACE

PRESSURES ARE RISING AND NORTHWESTERLY WINDS ARE INCREASING WHICH

IS HELPING TO ADVECT COOLER AND MUCH DRIER AIR INTO THE REGION.

SKIES SHOULD CLEAR BY EARLY EVENING FOR MOST AREAS...BUT WINDS

SHOULD REMAIN ABOVE 5-10 MPH TONIGHT WHICH WILL LIMIT OPTIMAL

RADIATIVE HEAT LOSS. MODELS HAVE INITIALIZED TOO MUCH SNOW COVER

REMAINING ACROSS THE NORTHERN ZONES...WHEN IN FACT MUCH OF THIS

HAS ALREADY MELTED. THE RESULT IS THAT TEMPERATURES /BOTH PERFECT

PROG AND MOS GUIDANCE/ LOOK TOO COOL IN THIS AREA. WILL FORECAST

TEMPS A FEW DEGREES WARMER THAN GUIDANCE...BUT STILL A VERY COLD

NIGHT IS EXPECTED WITH LOWS IN THE 20S AREA WIDE. LOTS OF SUNSHINE

IS EXPECTED SATURDAY AND WINDS WILL LAY DOWN DURING THE DAY...BUT

HIGH TEMPS WILL REMAIN CHILLY AND IN THE 40S. GOOD RADIATIONAL

COOLING IS EXPECTED SATURDAY NIGHT WITH THE TYPICAL COLDER

LOCATIONS BOTTOMING OUT IN THE UPPER TEENS.

THE WEATHER WILL BE IN TRANSITION DURING THE DAY SUNDAY AS A

STRONG UPPER LEVEL TROUGH DIGS INTO THE DESERT SOUTHWEST AND

BEGINS TO IMPACT OUR REGION. MID-HIGH LEVEL PACIFIC MOISTURE WILL

INCREASE DURING THE DAY AND SKIES SHOULD BE CLOUDY BY SUNSET.

SATURATION WILL OCCUR FROM TOP-DOWN...AND RAIN WILL BEGIN TO

BREAK OUT SUNDAY NIGHT. WITH THE DRY/COOL AIR INITIALLY BELOW THE

PRECIPITATING LAYER...WOULD NOT BE SURPRISED TO SEE SOME SLEET

MIXED WITH THE RAIN INITIALLY. HOWEVER SURFACE TEMPS WOULD BE

SAFELY ABOVE FREEZING WHEN THIS OCCURS. AS THE UPPER LEVEL IMPULSE

MOVES ACROSS THE AREA MONDAY...ISENTROPIC LIFT WILL BE VERY STRONG

AND TAP INTO SOME UNSEASONABLY HIGH AMOUNTS OF GULF MOISTURE.

EXPECT WIDESPREAD RAIN ACROSS THE REGION MONDAY...BUT IT SHOULD

END FROM WEST TO EAST MONDAY EVENING...PERHAPS SALVAGING NEW YEARS

EVE ACTIVITIES. IN THE WAKE OF THIS IMPULSE...WINDS WILL TURN TO

THE NORTH AND REINFORCE THE CHILLY WEATHER TUESDAY AND WEDNESDAY

WITH HIGHS IN THE 40S AND LOWS NEAR FREEZING.

FORECAST REMAINS A BIT UNCERTAIN WEDNESDAY AND THURSDAY AS ALL

MODEL GUIDANCE CONTINUES TO ADVERTISE ANOTHER PIECE OF UPPER LEVEL

ENERGY AT THE BASE OF THE TROUGH IN THE DESERT SOUTHWEST MOVING

IN FROM THE WEST WEDNESDAY NIGHT. THE AIRMASS WILL BE COLD ENOUGH

FOR SOME WINTRY PRECIP AND THE LIFT WILL CERTAINLY BE STRONG

ENOUGH. THE MISSING PIECE OF THE EQUATION IS MOISTURE BELOW 700MB.

IN FACT THERE IS UNANIMOUS AGREEMENT ON SNOW OCCURRING ALOFT OVER

THE AREA...BUT MOST GUIDANCE SHOWS TOO MUCH DRY AIR AT THE SURFACE

FOR THE SNOW TO WORK THROUGH TO REACH THE GROUND. THE ISSUE THAT

IS INHIBITING SNOW IS A VERY STRONG NORTHERN STREAM SHORTWAVE

TROUGH WHICH DROPS SOUTH FROM CANADA INTO THE PLAINS TUESDAY NIGHT

AND WEDNESDAY. THIS PIECE OF ENERGY SERVES TO KEEP/INTENSIFY THE

COLD/DRY AIRMASS IN THE LOW LEVELS WITH STRONGER NORTHERLY WINDS.

TO GET PRECIP WE WILL NEED TO SEE 850MB WINDS OPTIMALLY OUT OF A

SOUTHERLY DIRECTION...OR AT THE LEAST BECOME LIGHT ENOUGH TO LIMIT

THE DRY ADVECTION. A WEAKER NORTHERN STREAM SHORTWAVE TROUGH WOULD

ALLOW THE UPPER SYSTEM TO THE WEST TO TURN 850MB WINDS TO A MORE

FAVORABLE DIRECTION AND WOULD RESULT IN A WINTER EVENT FOR AT

LEAST PART OF OUR AREA. THE PIECE OF ENERGY IN QUESTION IS STILL

ROTATING AROUND AN UPPER LOW IN THE BEARING SEA...BUT SHOULD BE

SAMPLED BY ALASKAN/CANADIAN RAOBS IN 2-3 DAYS. FOR NOW ONLY THE

CANADIAN MODEL SHOWS THIS NORTHERN TROUGH BEING WEAK AND THEREFORE

HAS A SIGNIFICANT WINTER SYSTEM WEDNESDAY AND WEDNESDAY NIGHT.

THE ECMWF OFFERS A GOOD COMPROMISE...HAVING LIGHT QPF OVER THE

SOUTHERN ZONES WHERE THE LOW LEVEL AIRMASS WONT BE QUITE AS

DEEP/DRY. WILL INCLUDE A 20 POP FOR LIGHT RAIN ACROSS THE SOUTHERN

ZONES WEDNESDAY NIGHT...AND AWAIT A LITTLE MORE MODEL AGREEMENT

BEFORE RAISING CONCERNS FOR A WINTER EVENT IN THE OFFICIAL FCST.

TR.92

It seems like the models have been under doing moisture return with the last few systems

I know that in no way ensures that they are doing that again but it has been an interesting model trend as of late. I guess it will be an interesting trend, until it isn't, and a system comes in drier than modeled

[Srain]

The 12Z Euro was spitting out snow for Central Texas including San Antonio/Austin and even heavier amounts further N & W into El Paso and New Mexico. It certainly has the potential to be a high impact event for our Region. My concern is an Ice Storm a bit further S. We will see.

[#NoPoles]

OT, but Feliz Cumpleanos, wxmx!!! (in a few hrs)

[Srain]

A very interesting period appears to be ahead as we enter the New Year with many implications if the ensembles are correct for our Region. What does raise an eyebrow is the consistency being shown via the ensembles and the non American guidance that a more S into Northern Mexico track and a slowly progressing upper trough with embedded short waves rounding the base of that deep trough tapping into the Sub Tropic Jet with plentiful moisture streaming in from the Eastern Pacific. That is a classic winter weather recipe for an over running event and with the hints of waves of low pressure developing along a quasi stationary frontal boundary along the Coast down near the Rio Grande Valley and ripples of the waves riding ENE along that boundary. Past experience tells us it may be time to monitor things a bit closer. The trough continues to dig S along the California Coast this morning and this will be our New Years Eve rain/storm maker and bring the Canadian front through Texas on New Years Day. The second in a series of short waves is nearing British Colombia in Western Canada and will enter the RAOB (balloon radiosonde) network later tonight into tomorrow. That is what we will have to watch a bit more closely as it is that feature that is causing all the concern and chatter about closing off S of the Great Basin where a Ridge of High Pressure will be entrenched. I will say that what concerns me most is any potential ice threat we may have. It has been many years since we have seen a significant ice event across Southern half of Texas. With all the dead trees from the drought of last year and a couple of widespread high wide event this month, we have seen we have some real problems with these dead trees and Pines and Ice do not mix. I see the HPC is monitoring as well as NWS Houston/Galveston lending to credence to the Euro/Canadian ideas of a slower progressing, further S potential as well. Stay Tuned! This is a very low confidence forecast and things will change daily.

EXTENDED FORECAST DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD

120 AM EST SAT DEC 29 2012

VALID 12Z TUE JAN 01 2013 - 12Z SAT JAN 05 2013

...2013 TO START OFF 'COLD' ACROSS MUCH OF THE UNITED STATES...

ALONG THE WEST COAST...2 SYSTEMS TRACK SOUTH-SOUTHEASTWARD INTO

CALIFORNIA IN THE MEDIUM RANGE FORECAST PERIOD THEN MIGRATE

THROUGH THE SOUTHERN ROCKIES AND MIDDLE RIO GRANDE IN THE SOUTHERN

STREAM. TO MAINTAIN SOME CONTINUITY WITH THE PREVIOUS PROGS...USED

PIECES OF THE 28/12Z CANADIAN AND ECMWF RUNS. NOT MUCH OF THE

28/12Z & 29/00Z GFS COULD BE USED IN THE MEDIUM RANGE

GRAPHICS...INCLUDING THE MORE PROGRESSIVE...FASTER...AND FLATTER

GEFS MEANS.

THE PREVIOUS 2 RUNS OF THE CANADIAN (28/00Z & 28/12Z) WOULD BE

AGGRESSIVE SOLUTIONS ON DAY 3 ACROSS CALIFORNIA VS THE 28/18Z GEFS

MEAN...28/12Z ECMWF MEANS AND PREVIOUS 2 RUNS OF THE OPERATIONAL

ECMWF (28/00Z & 28/12Z). INTERESTINGLY...THE TREND OF THE

OPERATIONAL CANADIAN/ECMWF IS MORE OF AN OFFSHORE TRACK...WEST AND

SOUTH OF PT CONCEPCION. AND SLOWER. IN FACT...BOTH OF THESE

OPERATIONAL RUNS ARE SLOWER THAN THEIR CORRESPONDING ENSEMBLE

MEANS EVEN INTO DAY 4.

DAYS 4-5....THE CANADIAN CONTINUES TO BE THE AGGRESSIVE SOLUTION

IN THE NORTHERN GULF OF CALIFORNIA WITH ITS CLOSED H5 SOLUTION.

WITH THE 28/12Z CANADIAN AND ECMWF OPERATIONAL RUNS OFFERING

DECENT DETAILS WITH THIS SOUTHERN STREAM SYSTEM TIL DAY5...BEGAN

BLENDING IN THE 28/12Z ECMWF ENSEMBLE MEAN IN THE EAST

PACIFIC/WEST COAST TO OFFSET THE VERY SLOW 28/12Z CANADIAN

SOLUTION ALONG 130W. IN FACT...THE 28/12Z CANADIAN ENSEMBLE MEANS

LOOK TO BE SLOW OUTLIER IN THE NORTHERN PACIFIC DAY 5 VS THE

28/18Z GEFS MEAN AND 28/12Z ECMWF MEANS. THIS POSED A PROBLEM

AND/OR CHALLENGE INTO DAY 7 FOR MAINTAINING CONTINUITY...WOULD

MAKE THE OPERATIONAL CANADIAN THE PREFERRED SOLUTION. SEEMED OUT

OF PLACE FOR DAYS 6-7 ALTOGETHER FROM DATELINE TO 100W (CENTRAL

CONUS/PLAINS) .

ACROSS THE GREAT BASIN...INTERMOUNTAIN WEST AND THE ROCKIES...NOT

A TON OF CHANGES IN THE NEW PROGS. THE UPPER-LEVEL RIDGE

ESSENTIALLY HOLDS FIRM THROUGH DAY 7. WHAT EROSION THAT DOES OCCUR

LOOKS TO BE IN THE DAY 5-6 TIME FRAME WITH THE 2ND WEST COAST

SYSTEM SPLITTING AND TRACKING SOUTHEASTWARD. ENERGY MOVING ATOP

THE RIDGE AXIS AND INTO SOUTH CENTRAL BRITISH COLUMBIA QUICKLY

TRACKS EAST INTO THE DAKOTAS. THE LAST TWO RUNS OF THE ECMWF ARE

VERY COLD ACROSS THE GREAT BASIN AND COLORADO RIVER BASIN...WITH

SUB-ZERO READINGS IN NORTHERN NEVADA...PARTS OF WYOMING AND

COLORADO. NEAR TO BELOW FREEZING TEMPERATURES WERE AS FAR SOUTH AS

LAS VEGAS AND PHOENIX BY DAY 4-5!!!

FEW ADJUSTMENTS WERE NEEDED DOWNSTREAM IN THE CONFLUENT FLOW

ACROSS THE MIDWEST...GREAT LAKES AND POINTS EASTWARD TO THE

WESTERN ATLANTIC SHORELINE AND GULF COAST. MANUAL SFC/H5 GRAPHICS

BLENDED THE PREVIOUS 2 ECMWF RUNS FOR FINER DETAILS IN TANDEM WITH

THE 28/12Z ECMWF ENSEMBLE MEANS TO TRACK A PROCESSION OF CANADIAN

FRONTAL BOUNDARIES TRACKING THROUGH THE EAST AND SOUTHEAST. THE

NORTHERN GULF COAST AND EASTERN SHORES OF THE CAROLINAS WILL BE

THE WETTER AREAS OF THE COUNTRY TO START OFF THE NEW YEAR.

VOJTESAK

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX

444 AM CST SAT DEC 29 2012

.DISCUSSION...

IN THE SHORT TERM FORECAST LOOKS GOOD WITH HIGH PRESSURE OVER THE

AREA AND CIRRUS. TEMPERATURES WILL STILL BE ON THE COOL SIDE TODAY

WITH HIGHS ONLY STRUGGLING INTO THE LOWER TO MID 50S. THE HIGH

MOVES EAST ON SUNDAY AND EASTERLY FLOW SETS UP WITH A WARM FRONT

MOVING INTO THE COASTAL WATERS LATE IN THE AFTERNOON AND INTO THE

COASTAL COUNTIES MONDAY MORNING. THIS SHOULD LEAD TO LOW

CLOUDS/FOG/LIGHT RAIN WITH THE WARM FRONT GOING STATIONARY. THE

UPPER TROUGH OVER THE 4 CORNERS MONDAY MORNING STARTS TO MOVE EAST

THROUGHOUT THE DAY WITH MODERATE TO STRONG ISENTROPIC UPGLIDE

EXPECTING LIGHT RAIN THEN AS THE PROFILE DESTABILIZES MONDAY

AFTERNOON THE THREAT OF DEEPER CONVECTION DEVELOPS AND EXPECT TO

SEE SHOWERS AND THUNDERSTORMS. STILL EARLY BUT SPC HAS A SEE TEXT

IN PLACE FOR THE COASTAL AREAS AND MAY HAVE SOME BRIEF HEAVY

DOWNPOURS WITH A MODERATE LLJ. COLD FRONT MOVES THROUGH THE REGION

AND INTO THE GULF SLOWING DOWN AND GOING QUASI-STATIONARY

TUESDAY-THURSDAY. MODELS DIVERGING IN THE SOLUTIONS ON WEDNESDAY

WITH ANOTHER STRONG S/W DROPPING INTO THE WEST SIDE OF THE UPPER

TOUGH TO THE WEST...ECMWF IS DEEPER AND MUCH FURTHER SOUTH OVER

SOUTHERN BAJA AND THE GFS IF MORE PROGRESSIVE/NOT AS DEEP AND OVER

WEST TEXAS. EXPECT THAT THE GULF WATERS WILL SEE PLENTY OF UPGLIDE

-RA CLOUDS EXTENDING NORTH AND NORTHEAST OVER THE CWA HELPING TO

KEEP THE AREA COOLER DURING THE DAYTIME AND WARMER AT NIGHT...RAIN

CHANCES HIGHER NEAR THE COAST AND LOW OVER THE NORTH. GOING INTO

THURSDAY THE FORECAST GETS MORE INTERESTING WITH THE COLD AIR IN

PLACE PER THE ECMWF AND A RAPIDLY SATURATING COLUMN THE

POSSIBILITY OF SNOW MAY ARISE FOR THE NORTHWESTERN CWA...GFS IS

WARMER AND MUCH DRIER. NOT QUITE WILLING TO BITE OFF ON THE GFS

YET SO WILL KEEP A SLIGHT CHANCE/CHANCE OF RAIN GOING IN THE

FORECAST BUT IT COULD BUST BIG BOTH WAYS AT THIS POINT GIVEN THE

LOW CONFIDENCE. STAY TUNED.

[bubba hotep]

Looks like the 12z runs are trying to mix things up a bit come mid week. On my phone so it is hard to tell but it looks like temps might support freezing rain across the DFW area or sleet?

[DFWWeather]

From the NWS office in Fort Worth:

.UPDATE...

HIGH CLOUDS ARE INCREASING TO THE SOUTHWEST AND HIGH TEMPS MAY BE

A BIT TOO WARM IN THE SOUTHWEST ZONES. HAVE LOWERED TEMPS A BIT IN

THIS AREA...AND MADE SOME AMENDMENTS TO TONIGHT/S LOWS BASED ON

MORE CLOUD COVER ARRIVING SOONER.

12Z MODEL DATA IS ROLLING IN NOW...AND SOME PRETTY SIGNIFICANT

CHANGES ARE OCCURRING TO THE FORECAST SYNOPTIC PATTERN ACROSS THE

WESTERN HALF OF THE CONTINENT AROUND THE MID-LATE WEEK TIME

FRAME. MAY NEED TO ADD POPS TO THE ENTIRE AREA WEDNESDAY

NIGHT...AND WILL NEED TO INVESTIGATE A POTENTIAL FOR

FREEZING/FROZEN PRECIP AS WELL.

The upper air pattern for this event does not look too different from what occurred around February 24, 2003 where several inches of sleet and ice accumulated. Although current progs would push the system a bit further south.

[Ed Lizard]

Liking the forecasts for needed rain, but last couple of cold fronts, strong North winds over the offshore waters (and even some 'ocean affect' type clouds') makes me fear the NW Gulf will be chilly March-May, causing low clouds that don't want to burn off allowing insolation and cap bustin', and missed Spring fun-derstorm opportunities.

For the hurricane fans (and I'd be very happy with TS and low end Cat 1s the next decade or so until we can full, solid, good return on fun/investment on the rebuilt Popo Party Pad on GLS) even a cold Winter doesn't seem to affect NW Gulf temps in the August-September prime-time.

But I believe if while old weenie can appreciate hurricanes, it is a further level of sophistication to enjoy large hail (we need a new roof in the next few anyway, and the 2007 Impala is paid off, and the Sienna is parked indoors) and winds over 50 knots.

May have finally had a 50 knot wind gust based on an IAH post-frontal Christmas Day gust to 50 mph, but don't think I have had a t-storm related 50 knot gust IMBY since Ike. And, technically, I don't recall any lightning/thunder w/ Ike...

[Srain]

Morning e-mail from Jeff:

Extended period of cold wet weather likely.

Changes underway this morning as large slow moving upper level trough drops southward west of CA toward Baja as lead short wave is starting to move eastward over MX. At the surface, features are starting to respond to the approaching trough over the western US with coastal surface warm front and surface low beginning to take shape off the lower TX coast. ENE winds have increased this morning north of the warm front which is well offshore the upper TX coast. Mid level cloud deck is advancing ENE in the SW flow aloft and this deck will thicken and lower with time today as warm moist air is lifted over the top of the retreat surface cold dome. Moisture return begins in earnest tonight and expect a rapid decline in conditions across the area as the low levels saturate. Will start to see fog and drizzle/light rain develop over the Gulf waters and shift inland tonight as the warm front nears the coast.

On Monday the first short wave ejects across the plains with the surface warm front likely moving just inland from the coast…possibly as far north as I-10 by Monday evening. Numerous showers and thunderstorms will be likely over the region on Monday first along and ahead of the warm front and then along and ahead of the cold front early Tuesday morning. While the warm front will be over the heart of this area, instability is greatly lacking with forecasted values of 200-500 J/kg compared to 1000-2000 J/kg on Christmas and this suggest a smaller severe threat compared to the Christmas event. Cold front cutting into the warm sector early Tuesday morning may result in a few marginal severe storms with the main threats being hail and strong winds.

Another concern will be rainfall as moisture levels will be very high for this time of year and there is a window from Monday afternoon through Tuesday morning for a period of cell training which is shown nicely in the Texas Tech WRF model. Given the high levels of moisture that will be in place this does raise some concern for flooding and this will need close watch on Monday. Widespread rainfall amounts of .50 to 2.0 inches appears likely Monday-Tuesday.

Extended:

Cold front slowly pushes offshore on Tuesday and becomes stationary as the upper flow is out of the SW and parallel to the boundary. Main upper trough remains anchored WSW of the region over N MX with short waves rotating through the trough and then into the southern plains. While the GFS had trended toward the wetter ECMWF over the past 24 hours the latest run is back to its drier pattern while the ECMWF remains firm on a cold wet pattern through the end of the week. With the cold front stalled off the coast and the main trough hanging back to the WSW this provides a good pattern for moisture to overrun the cold surface dome. The question is how much dry air sinks southward in the low levels and/or where does the front stall. Current thinking is that the front will stall close enough to the coast that moisture will remain plentiful over SE TX and the coastal bend with periods of rainfall developing from SW to NE during the entire period from Wed-early Friday. Additional widespread rainfall of 1-2 inches seems possible from Wed-Fri.

Other question to deal with is the threat for any frozen or freezing precipitation in the Wed-Fri period. ECMWF would suggest a chance of rain changing to snow NW of a line from LaGrange to Brenham to Conroe on Thursday as cooling aloft with the upper trough moves into the area. GFS shows a much drier profile and does not support snow in the area, although Thursday morning dewpoints at College Station are in the upper 20’s/low 30’s with air temperatures in the mid 30’s…but this would still suggest rain as there would be little room for evaporative cooling. For now will keep everything rain, as the upstream air mass while cold is not overly cold for this time of year and there is not significant model agreement on moisture or temperature profiles over the northwest 1/3rd of the area for Wed-Thur. Will need to keep a watchful eye on this aspect moving forward over the next 24-36 hours

[Srain]

Some light sleet/rain mix being reported across Central Texas this morning...