Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 5

[bubba hotep]

Folks, don't put away your winter coats just yet! Old Man Winter doesn't appear to be quite done with us yet...

 

test8.gif

 

I've been watching that but tend to favor the glancing blow scenarios over the direct dump.  However, there is plenty of time for the details to get worked out.   It does look like the Great Lakes will be frozen solid before spring gets here

[DFWWeather]

I've been watching that but tend to favor the glancing blow scenarios over the direct dump.  However, there is plenty of time for the details to get worked out.   It does look like the Great Lakes will be frozen solid before spring gets here

 

Yeah, I was reading where Superior was over 90% frozen and that it would be August before total thaw, when usually May/June the lakes warm. This might spell cooler than normal summer for areas downwind. Also, wondering with weak El Nino developing whether this summer is going to be wetter and not quite so hot for DFW, maybe even tad below normal? Be interesting to see trends. I definitely don't think we will be near as hot as last couple of summers.

[Quixotic1]

I've been watching that but tend to favor the glancing blow scenarios over the direct dump.  However, there is plenty of time for the details to get worked out.   It does look like the Great Lakes will be frozen solid before spring gets here

 

I'm up in MO and the rivers are frozen pretty well.  First time I've seen it this way. 

[bubba hotep]

00z & 12z GFS are offering up a lol ice storm for DFW in early March. Has a major ice storm ever hit in March?

[DoctorMu]

00z & 12z GFS are offering up a lol ice storm for DFW in early March. Has a major ice storm ever hit in March?

 

lol  Way out in Fantasyland:

 

[DoctorMu]

I'm up in MO and the rivers are frozen pretty well.  First time I've seen it this way. 

 

 

Well to the east is the Ohio River frozen?  Haven't seen that since the late 70s...?

[DFWWeather]

00z & 12z GFS are offering up a lol ice storm for DFW in early March. Has a major ice storm ever hit in March?

 

Yes, on several occasions. However, March usually tends to be more snow than ice, but given the track record this year, snow or ice wouldn't be out of the question. Some noteworthy examples are March 13, 1924 6 inches of snow fell, March 1, 1942 4.5 inches of snow fell (coincidentally on March 8, 1942 1.6 inches fell again), March 15, 1900 0.6 inches of sleet/ice fell. March 17, 1934 0.9 inches of sleet/ice fell, March 7, 1947 almost 4 inches of snow fell.

[NTXYankee]

lol  Way out in Fantasyland:

 

Ok yuck, especially after the last several days of nice weather. However if fantasyland comes true, we need the precip so take what we can get.

[Srain]

Drought Update from Jeff:

 

After a brief relaxing of drought conditions toward the end of 2013, conditions have rapidly deteriorated again in early 2014 with nearly all of SE TX now in some form of drought.

 

In fact January 2014 was the 5^th driest January on record for the state of state with an average precipitation of only .39 of an inch statewide making January 2014 the driest January since 1971! Rainfall has been sorely lacking across much of the state since early December 2013. The last significant rainfall to occur in SE TX happened the weekend before Thanksgiving and since then rainfall deficits have increased into the 4-8 inch range since January 1^st across SE TX. This is on top of the rainfall deficits of 10-15 inches in 2013. Colder than normal temperatures have made the increasing dryness less noticeable along with the frequent bouts of cloudy and drizzly weather…however meaningful rainfall has been scarce in what is traditionally our wetter period of the year and when statewide water supplies tend to build for the coming warm season month drawdowns.

 

US Drought Monitor:

The latest drought Monitor map dated February 11, 2014 (see bottom map) shows all of SE TX in some form of drought. Locations mainly along and north of HWY 105 are considered in D0 or abnormally dry conditions. D1, moderate drought, is found for most locations south of HWY 105 with D2 severe drought found across Brazoria County and surrounding Matagorda Bay. A total of 89% of the state of Texas is currently in some form of drought compared to only 10% a year ago at the same time.

 

Historical Statistics:

 

I was preparing a presentation on the status of the drought in mid-January for a speaking engagement and took a look at the last 6 years of rainfall for the following climate sites of Houston (IAH), Victoria, and Corpus Christi, and Austin. I was absolutely stunned at some of the numbers! The following is the 6-year rainfall departures for the following locations through December 31, 2013 (2008-2013):  

 

Houston IAH: -50.16

 

Victoria: -81.41

 

Corpus Christi: -43.71

 

Austin: -25.73

 

The incredible lack of rainfall at Victoria is simply amazing…put in another way the -81.41 inch rainfall deficit is equal to two entire years’ worth of rainfall missing from the climate record at this location! For Houston IAH over an entire years’ worth of rainfall is missing from the climate record and rainfall has been below average each year since 2009 or since the landfall of Hurricane Ike. Since the landfalls of hurricanes Dolly and Ike in 2008 the state has been suffering one of its driest periods ever rivaling that of the decade long drought of record of the 1950’s. It is interesting to note that if you remove the total rainfall from hurricane Ike at BUSH IAH, 2008 would have ended with below normal rainfall…with Ike’s total added in 2008 only ended 3.23 inches above normal. This shows both the power of the tropics to bring summer and early fall rainfall and just how significant the dryness has been as the combined rainfall from Dolly and Ike in 2008 just barely pushed the 2008 yearly total slightly above average. It is also interesting to note that both of the 2008 tropical systems failed to produce rainfall in a swath from near Victoria to Austin and both ended 2008 with significant rainfall departures of -19.51 (Victoria) and -16.17 (Austin). See attached PPT side.  

 

Water Supply/Lake Levels:

 

The winter and spring months tend to be the re-charge time period for water supply reservoirs across the state, but the end of 2013 and the start of 2014 has not produced much significant inflow into our lakes. In fact streamflow conditions are running below base flow across much of the state and in portions of central and northwest TX even a significant rainfall event might not generate much run-off into rivers and streams given how dry conditions have become. Current statewide storage is at 64.0% down from 66.9% a year ago. Interestingly the statewide storage going into spring of 2013 was about 2% higher than current. Also of note has been a complete lack of statewide recovery in levels since the past summer lows around 62%...which gives an indication of just how dry the area has been over the winter months.

 

Lake level Departures and (Percent of Capacity):

 

Lake Buchanan: -30.62 (38%)

Lake Conroe: -1.18 (94%)

Lake Houston: 0.00 (100%)

EV Spence: -69.29 (3.2%)

Falcon: -24.72 (39%)

Lake Livingston: +.28 (100%)

OC Fisher: -59.12 (0.6%)

Sam Rayburn: -3.57 (87%)

Lake Somerville: -2.71 (81%)

Lake Texana: -3.41 (81%)

Lake Travis: -53.25 (36%)

Toledo Bend: -2.91 (89%)

Choke Canyon: -23.54 (33%)

 

While water supply levels across SE TX are doing well especially east of I-45 locations across central TX especially in the drought stricken Colorado River basin are much more dire. The multi-year drought has had severe impacts on the Highland lakes water supply. LCRA indicates the current combined total storage of the highland lakes chain is 38% or 762,456 acre feet of water. The inflow into the Highland lakes in January 2014 was only 11,763 acre-feet or roughly 18% of normal….this is the lowest January inflow since the decade long drought from 1947-1957 which is also the drought of record for the Highland lakes chain. Of the top 10 lowest inflows on record into the Highland lakes, 5 have been since 2008. 2011 was the lowest amount of inflow ever record at 127,802 acre-feet for the entire year and 2013 is ranked as the second lowest amount of inflow of 216,353 acre-feet. The past 5-year period of inflows into the Highland lakes has been the worst ever recorded surpassing the historic drought of record from the 1950’s.

 

Of even more interest is that the total January inflow for the past 3 years equals 62,058 acre-feet which does not even equal 1 year of January average inflow of 62,858 acre-feet…indicating just how dry the previous winters have also been and why there has been such little recovery on the Highland lakes system.

 

It appears likely that emergency action will have to be taken in 2014 which includes completely cutting off releases to downstream farmers and potentially limiting FIRM customers in central Texas.

 

Per TCEQ a total of 382 jurisdictions currently have voluntary water restrictions in place across the state and 752 have mandatory restrictions with a total of 1137 systems currently being affect and requesting some form of public action (see map below).

 

 

Fire Weather:

61 out of 254 TX counties are currently under outdoor burn bans. The only County in SE TX under a burn ban is Galveston County. Thus far strong cold frontal passages this winter have been accompanied by post frontal drizzle and cloud cover helping keep fire weather concerns at a minimum. However recent warming temperatures and gusty winds along with dead fine fuels from hard winter freezes are setting the stage for a more robust period of fire weather concerns over the next month if wetting rainfall does not occur. KBDI values which indicate the amount of dryness in the top layer of soil and equate to vegetation health are running in the 0-200 range across most of SE TX with 0 being wet and 800 being completely void of moisture to a depth of 8 inches. KBDI values are higher around Matagorda Bay and range from 400-500. Large fuel health is doing much better than the finer fuel grasses.  

 

The big concern over the next few weeks will be dry, warm, and windy afternoons prior to green up of dead grasses which could promote rapid and uncontrolled grass fire spread. Conditions later this week look fairly ripe for near critical fire weather conditions along and west of I-35 with RH values in the teens and gusty NW winds on Friday. Given this area has seen even less rainfall development the spread of large scale wild/grass fires will be possible. 

 

Tree Cover Impact:

Statistics have been compiled by the Texas Forest Service indicating the total losses from the 2011 drought which continue to this date. A staggering 301 million trees have been lost as a result of the 2011 drought with one of the worst affected areas being in the Brazos Valley area where nearly 10% of the tree canopy was killed. In addition to the 301 million rural and forest trees that died a total of 5.6 million urban trees were also lost including over 80% of the entire canopy of Memorial Park. Extensive efforts have been ongoing since early 2012 to attempt to replant some of the lost canopy in the urban areas.  

 

Agriculture Impacts:

Winter wheat production across Texas has suffered from both the lack of rainfall and colder than normal temperatures.  The greatest soil moisture departures are noted around Victoria and Matagorda Bay and range from -60 to -80 mm. While soil moisture departures are not overly dry they are not wet either and there is much concern that spring planting which is imminent may face some issues if wetting rainfall does not occur in the next 2-3 weeks. Cattle continue to decline across the state a result of poor water supply in stock ponds and feeder streams and poor vegetation health.

 

Supplements of hay are being required across the portions of central and west Texas where drought has ravaged winter supplies of cold season forage. Additionally, multi-year drought has resulted in poor field production in many areas. 

 

Spring Outlook:

Global weather patterns that favor southern plains and Texas drought have been in place for the last 5-10 year and closely mimic that of the 1950’s which brought Texas its drought of record….thus it is no big surprise that the last several years have been exceedingly dry across the state. There is little indication that these temperature patterns over the Pacific and Atlantic Oceans are changing and if they did it would be slow or on the course of years not months. Thus the overall trend will continue to be a dry trend for the state until there is a change within the decadal oscillations that have brought us to this point.

 

On a shorter term climate picture…the next 3 months…there appears to be little change from the current dry pattern. ENSO neutral conditions in the central Pacific does not support either above or below normal rainfall for Texas, but with the overall background climate patterns supporting below normal rainfall and the fact that the last month was extremely dry…I am leaning toward a drier than average spring. March is typically one of our driest months and the weather pattern appears to be looking similar to past springs where weather producing systems are just too far north and east of TX to produce much wetting rainfall. Not saying there will not be a couple good soaking rains…but steady and frequent rainfall looks doubtful as we head toward summer.

 

Dry grounds will result in increasing surface temperatures as the sun angle rises higher in the sky which will increase evaporation rates which in turn dries the ground more and we get into the nonstop cycle which is very difficult to break…the old saying drought begets drought. The amount of wind will also play an important part in those evaporation rates especially across water supply lakes…the windier it is the more evaporation and loss. As we move toward summer, fronts that might bring rainfall in the spring will cease and our only hope for widespread wetting rains will come from the tropics.

 

There is some hope toward next fall as there appears to be growing support in the long range model community for the development of at least low end El Nino conditions in the central Pacific (warming of the central Pacific water) which usually results in wetter and cooler than normal conditions for the state of Texas. However this will not help prior to next fall and between now and then lies a potentially hot and dry summer.    

[Quixotic1]

Well to the east is the Ohio River frozen?  Haven't seen that since the late 70s...?

I just saw something on Yahoo about someone being rescued from the Ohio River. 

 

My sister lives in Cincy and they said the rivers are frozen.  The big ones not solidly.  Said it has been decades since that's happened. 

[Ed Lizard]

Still have a few scattered green leaves on the water oak.  Not many.  But I will hold out as long as it has one green leaf.

 

 

Hoping we get lucky...

[Chinook]

Texas loves us

 

 

 

 

 

[bubba hotep]

Drought Update from Jeff:

 

After a brief relaxing of drought conditions toward the end of 2013, conditions have rapidly deteriorated again in early 2014 with nearly all of SE TX now in some form of drought.

 

In fact January 2014 was the 5^th driest January on record for the state of state with an average precipitation of only .39 of an inch statewide making January 2014 the driest January since 1971! Rainfall has been sorely lacking across much of the state since early December 2013. The last significant rainfall to occur in SE TX happened the weekend before Thanksgiving and since then rainfall deficits have increased into the 4-8 inch range since January 1^st across SE TX. This is on top of the rainfall deficits of 10-15 inches in 2013. Colder than normal temperatures have made the increasing dryness less noticeable along with the frequent bouts of cloudy and drizzly weather…however meaningful rainfall has been scarce in what is traditionally our wetter period of the year and when statewide water supplies tend to build for the coming warm season month drawdowns.

 

US Drought Monitor:

The latest drought Monitor map dated February 11, 2014 (see bottom map) shows all of SE TX in some form of drought. Locations mainly along and north of HWY 105 are considered in D0 or abnormally dry conditions. D1, moderate drought, is found for most locations south of HWY 105 with D2 severe drought found across Brazoria County and surrounding Matagorda Bay. A total of 89% of the state of Texas is currently in some form of drought compared to only 10% a year ago at the same time.

 

Historical Statistics:

 

I was preparing a presentation on the status of the drought in mid-January for a speaking engagement and took a look at the last 6 years of rainfall for the following climate sites of Houston (IAH), Victoria, and Corpus Christi, and Austin. I was absolutely stunned at some of the numbers! The following is the 6-year rainfall departures for the following locations through December 31, 2013 (2008-2013):  

 

Houston IAH: -50.16

 

Victoria: -81.41

 

Corpus Christi: -43.71

 

Austin: -25.73

 

The incredible lack of rainfall at Victoria is simply amazing…put in another way the -81.41 inch rainfall deficit is equal to two entire years’ worth of rainfall missing from the climate record at this location! For Houston IAH over an entire years’ worth of rainfall is missing from the climate record and rainfall has been below average each year since 2009 or since the landfall of Hurricane Ike. Since the landfalls of hurricanes Dolly and Ike in 2008 the state has been suffering one of its driest periods ever rivaling that of the decade long drought of record of the 1950’s. It is interesting to note that if you remove the total rainfall from hurricane Ike at BUSH IAH, 2008 would have ended with below normal rainfall…with Ike’s total added in 2008 only ended 3.23 inches above normal. This shows both the power of the tropics to bring summer and early fall rainfall and just how significant the dryness has been as the combined rainfall from Dolly and Ike in 2008 just barely pushed the 2008 yearly total slightly above average. It is also interesting to note that both of the 2008 tropical systems failed to produce rainfall in a swath from near Victoria to Austin and both ended 2008 with significant rainfall departures of -19.51 (Victoria) and -16.17 (Austin). See attached PPT side.  

 

Water Supply/Lake Levels:

 

The winter and spring months tend to be the re-charge time period for water supply reservoirs across the state, but the end of 2013 and the start of 2014 has not produced much significant inflow into our lakes. In fact streamflow conditions are running below base flow across much of the state and in portions of central and northwest TX even a significant rainfall event might not generate much run-off into rivers and streams given how dry conditions have become. Current statewide storage is at 64.0% down from 66.9% a year ago. Interestingly the statewide storage going into spring of 2013 was about 2% higher than current. Also of note has been a complete lack of statewide recovery in levels since the past summer lows around 62%...which gives an indication of just how dry the area has been over the winter months.

 

Lake level Departures and (Percent of Capacity):

 

Lake Buchanan: -30.62 (38%)

Lake Conroe: -1.18 (94%)

Lake Houston: 0.00 (100%)

EV Spence: -69.29 (3.2%)

Falcon: -24.72 (39%)

Lake Livingston: +.28 (100%)

OC Fisher: -59.12 (0.6%)

Sam Rayburn: -3.57 (87%)

Lake Somerville: -2.71 (81%)

Lake Texana: -3.41 (81%)

Lake Travis: -53.25 (36%)

Toledo Bend: -2.91 (89%)

Choke Canyon: -23.54 (33%)

 

While water supply levels across SE TX are doing well especially east of I-45 locations across central TX especially in the drought stricken Colorado River basin are much more dire. The multi-year drought has had severe impacts on the Highland lakes water supply. LCRA indicates the current combined total storage of the highland lakes chain is 38% or 762,456 acre feet of water. The inflow into the Highland lakes in January 2014 was only 11,763 acre-feet or roughly 18% of normal….this is the lowest January inflow since the decade long drought from 1947-1957 which is also the drought of record for the Highland lakes chain. Of the top 10 lowest inflows on record into the Highland lakes, 5 have been since 2008. 2011 was the lowest amount of inflow ever record at 127,802 acre-feet for the entire year and 2013 is ranked as the second lowest amount of inflow of 216,353 acre-feet. The past 5-year period of inflows into the Highland lakes has been the worst ever recorded surpassing the historic drought of record from the 1950’s.

 

Of even more interest is that the total January inflow for the past 3 years equals 62,058 acre-feet which does not even equal 1 year of January average inflow of 62,858 acre-feet…indicating just how dry the previous winters have also been and why there has been such little recovery on the Highland lakes system.

 

It appears likely that emergency action will have to be taken in 2014 which includes completely cutting off releases to downstream farmers and potentially limiting FIRM customers in central Texas.

 

Per TCEQ a total of 382 jurisdictions currently have voluntary water restrictions in place across the state and 752 have mandatory restrictions with a total of 1137 systems currently being affect and requesting some form of public action (see map below).

 

 

Fire Weather:

61 out of 254 TX counties are currently under outdoor burn bans. The only County in SE TX under a burn ban is Galveston County. Thus far strong cold frontal passages this winter have been accompanied by post frontal drizzle and cloud cover helping keep fire weather concerns at a minimum. However recent warming temperatures and gusty winds along with dead fine fuels from hard winter freezes are setting the stage for a more robust period of fire weather concerns over the next month if wetting rainfall does not occur. KBDI values which indicate the amount of dryness in the top layer of soil and equate to vegetation health are running in the 0-200 range across most of SE TX with 0 being wet and 800 being completely void of moisture to a depth of 8 inches. KBDI values are higher around Matagorda Bay and range from 400-500. Large fuel health is doing much better than the finer fuel grasses.  

 

The big concern over the next few weeks will be dry, warm, and windy afternoons prior to green up of dead grasses which could promote rapid and uncontrolled grass fire spread. Conditions later this week look fairly ripe for near critical fire weather conditions along and west of I-35 with RH values in the teens and gusty NW winds on Friday. Given this area has seen even less rainfall development the spread of large scale wild/grass fires will be possible. 

 

Tree Cover Impact:

Statistics have been compiled by the Texas Forest Service indicating the total losses from the 2011 drought which continue to this date. A staggering 301 million trees have been lost as a result of the 2011 drought with one of the worst affected areas being in the Brazos Valley area where nearly 10% of the tree canopy was killed. In addition to the 301 million rural and forest trees that died a total of 5.6 million urban trees were also lost including over 80% of the entire canopy of Memorial Park. Extensive efforts have been ongoing since early 2012 to attempt to replant some of the lost canopy in the urban areas.  

 

Agriculture Impacts:

Winter wheat production across Texas has suffered from both the lack of rainfall and colder than normal temperatures.  The greatest soil moisture departures are noted around Victoria and Matagorda Bay and range from -60 to -80 mm. While soil moisture departures are not overly dry they are not wet either and there is much concern that spring planting which is imminent may face some issues if wetting rainfall does not occur in the next 2-3 weeks. Cattle continue to decline across the state a result of poor water supply in stock ponds and feeder streams and poor vegetation health.

 

Supplements of hay are being required across the portions of central and west Texas where drought has ravaged winter supplies of cold season forage. Additionally, multi-year drought has resulted in poor field production in many areas. 

 

Spring Outlook:

Global weather patterns that favor southern plains and Texas drought have been in place for the last 5-10 year and closely mimic that of the 1950’s which brought Texas its drought of record….thus it is no big surprise that the last several years have been exceedingly dry across the state. There is little indication that these temperature patterns over the Pacific and Atlantic Oceans are changing and if they did it would be slow or on the course of years not months. Thus the overall trend will continue to be a dry trend for the state until there is a change within the decadal oscillations that have brought us to this point.

 

On a shorter term climate picture…the next 3 months…there appears to be little change from the current dry pattern. ENSO neutral conditions in the central Pacific does not support either above or below normal rainfall for Texas, but with the overall background climate patterns supporting below normal rainfall and the fact that the last month was extremely dry…I am leaning toward a drier than average spring. March is typically one of our driest months and the weather pattern appears to be looking similar to past springs where weather producing systems are just too far north and east of TX to produce much wetting rainfall. Not saying there will not be a couple good soaking rains…but steady and frequent rainfall looks doubtful as we head toward summer.

 

Dry grounds will result in increasing surface temperatures as the sun angle rises higher in the sky which will increase evaporation rates which in turn dries the ground more and we get into the nonstop cycle which is very difficult to break…the old saying drought begets drought. The amount of wind will also play an important part in those evaporation rates especially across water supply lakes…the windier it is the more evaporation and loss. As we move toward summer, fronts that might bring rainfall in the spring will cease and our only hope for widespread wetting rains will come from the tropics.

 

There is some hope toward next fall as there appears to be growing support in the long range model community for the development of at least low end El Nino conditions in the central Pacific (warming of the central Pacific water) which usually results in wetter and cooler than normal conditions for the state of Texas. However this will not help prior to next fall and between now and then lies a potentially hot and dry summer.    

 

We need rain up this way as well:

 

[Srain]

Morning Update from Jeff:

 

Strong cold front will bring much colder air and high rain chances to the region.

 

Current ill defined frontal boundary lying across the area with dense sea fog once again in place along the coast and spreading inland to I-10. Boundary appeared to have moved through the I-10 corridor around 400am and now appears to have backed northward allowing sea fog to spread back inland. Visibilities have been going down most of the morning from US 59 southward. Think it may be hard to clear out the sea fog on the coast today unless a better push of drier air moves down from the NNE and this is looking suspect at the moment.

 

Bigger item of interest is the incoming strong frontal boundary Tuesday and potential for some decent wetting rainfall. Shorter term models have trended wetter overnight with amounts adding some hope that the incoming system may in fact generate some short term drought relief over the region. Strong frontal boundary will arrive into the region Tuesday afternoon and cross the area Tuesday evening with showers and possibly a thunderstorm developing ahead of the boundary and then potentially widespread rainfall behind the boundary in the cold air. Temperatures will quickly fall from the humid 70’s into the 40’s behind this front as the area receives a glancing blow of arctic air. Advancing cold air will end the sea fog threat for the rest of the week after Tuesday.

 

Looks like rains will continue into Wednesday morning as moisture is brought up and over the surface cold dome. Current model QPF fields along with HPC progs suggest a solid .50 of an inch across the area with isolated totals of 1.0-1.5 inches possible especially toward the coast where rains may linger the longest. Would not rule out a period of cell training of heavier elevation convection at some point Tuesday night which could push totals a little higher in a few narrow bands.

 

Rains look to end on Wednesday but front stalls not far off the coast and cloud cover will linger. Expect cold temperatures with highs likely in the low 50’s under gusty north winds. Not overly sure the area will see much sun on Thursday or Friday either as SW flow aloft looks to push Pacific moisture toward the area…but will keep rain chances on the low side (20%) for now. Could see a couple of disturbances ride up and out of MX in this flow helping to generate a few showers if there is enough moisture around near the surface. Temperatures will remain below normal for this time of year into Friday before winds turn back to the south.

 

Active flow pattern aloft continues into next week with some additional rain chances helping to ease some of the building drought across the area.

 

Next 7-Day Rainfall Amounts: 

[Srain]

EWX reports sleet falling in Georgetown (I-35 @ HWY 29)

[DoctorMu]

EWX reports sleet falling in Georgetown (I-35 @ HWY 29)

 

 

Yeah, we're headed up to Temple and the DP is 19 (temp = 36°) with a chance of some kind of precip.  Models underestimating the cold surge not surprisingly.

[1900hurricane]

I'm sick of winter. It's overstayed its welcome. At least there could be some decent warm sector thunderstorms Sunday...

[1900hurricane]

ZCZC SPCSWOD48 ALL
ACUS48 KWNS 270947
SPC AC 270947

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0347 AM CST THU FEB 27 2014

VALID 021200Z - 071200Z

...DISCUSSION...
SUNDAY /DAY 4/ MODELS HAVE TRENDED TOWARD THE ECMWF REGARDING THE
TIMING AND AMPLITUDE OF A SHORTWAVE TROUGH THAT WILL MOVE THROUGH
THE SRN PLAINS AND LOWER MS VALLEY AREA. PRECEDING THIS FEATURE AN
ARCTIC FRONT WILL ADVANCE SWD INTO A PORTION OF THE SRN PLAINS AND
LOWER MS VALLEY. LOWER VERTICAL RESOLUTION SPECTRAL MODELS TEND TO
BE A BIT SLOWER WITH SHALLOW ARCTIC SURGES...SO THE SOMEWHAT FASTER
NAM SOLUTION MAY BE REASONABLE. BY 12Z SUNDAY THIS BOUNDARY WILL
LIKELY EXTEND FROM NRN AR SWWD INTO NWRN TX AND ADVANCE TO SCNTRL TX
INTO NRN LA EARLY SUNDAY EVENING.

DEWPOINTS IN THE UPPER-MID 60S WILL HAVE ADVECTED THROUGH THE TX
PRE-FRONTAL WARM SECTOR WITH LOW-MID 60S EXPECTED FARTHER EAST INTO
THE LOWER MS VALLEY. MODERATE INSTABILITY MAY RESIDE OVER NWRN AND
NCNTRL TX WED MORNING WHERE RICHER MOISTURE WILL HAVE ADVECTED
BENEATH STEEPER LAPSE RATES...BUT ATMOSPHERE IN THIS REGION MAY
REMAIN CAPPED. STORMS MAY INITIATE ALONG THE FRONT OVER NCNTRL TX
DURING THE MORNING AND SUBSEQUENTLY DEVELOP SEWD THROUGH ERN
TX...REACHING THE LOWER MS VALLEY BY EVENING. WINDS IN THE SFC-700
MB LAYER ARE INITIALLY EXPECTED TO BE MODEST...BUT WITH VERTICAL
SHEAR THROUGH A DEEPER LAYER OF 40+ KT. A FEW STORMS FROM NCNTRL
THROUGH ERN TX MAY POSE A THREAT FOR ISOLATED LARGE HAIL AND
DAMAGING WIND...THOUGH THERE MAY BE SOME TENDENCY FOR ANY STORMS
DEVELOPING ON THE FRONT TO BE UNDERCUT WHICH WOULD MITIGATE THE WIND
THREAT.

OVERNIGHT...THE LLJ IS FORECAST TO STRENGTHEN OVER THE LOWER MS
VALLEY WHERE INSTABILITY WILL BE SOMEWHAT WEAKER. SOME THREAT WILL
PERSIST FOR ISOLATED DAMAGING WIND GUSTS ALONG WITH A CONDITIONAL
THREAT FOR A TORNADO...BEFORE ACTIVITY BEGINS TO OUTRUN MOIST AXIS
LATER SUNDAY NIGHT.

WHILE AN INTRODUCTION OF AT LEAST A LOWER END SLIGHT RISK AREA IS
PROBABLE IN LATER UPDATES...CONFIDENCE IS NOT SUFFICIENT AT THIS
TIME TO DELINEATE A 30% OR GREATER COVERAGE AREA. BEYOND DAY 4
OVERALL SEVERE POTENTIAL APPEARS LOW UNTIL POSSIBLY DAY 8 ACROSS FL.

..DIAL.. 02/27/2014

[Srain]

The over night guidance is slowly trending toward a solution that may offer a bout of strong to possibly severe storms Sunday afternoon/evening as disturbance moves E across the Southern Plains and a strong Polar front drops S into Texas. The big question is how much capping issues will play in inhibiting storm development during peak heating on Sunday in advance of the cold front and if the greatest threat for a severe potential would extend from Central Texas on NE into Arkansas. The SPC is mentioning the potential but the uncertainties preclude a mention of any real Risk in the Day 4 to 8 Outlook. We may see the SPC introduce a Slight Risk sometime over night into tomorrow night if the data suggests a Slight Risk is warranted.

 

[1900hurricane]

With an arctic front adjacent to the warm sector, this is one of those times that I'm slightly worried about the undercutting of any surface based storms. Models have been trending away from burying the arctic high down the spine of the Rockies though, so it might not end up being a problem, but it'll be something to watch.

[aggiegeog]

Made it into the teens at my place this morning. Sunday should be an interesting forecast, the line between strong storms and ice will be fairly close.

[1900hurricane]

 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
351 PM CST THU FEB 27 2014

.DISCUSSION...
HIGH PRESSURE OVER THE AREA SLIDING EAST WHICH HAS GIVEN THE AREA
A NICE COOL AND DRY AFTERNOON. THE HIGH CONTINUES EAST ON FRIDAY
AND AN UPPER LEVEL DISTURBANCE OVER THE FOUR CORNERS AREA THIS
AFTERNOON SWINGS EAST ALONG THE RED RIVER. THIS SHOULD PUSH A
PACIFIC FRONT INTO THE HILL COUNTRY WITH MOST IF NOT ALL OF SETX
CAPPED. PERHAPS THE FAR NORTHEAST AREAS MAY GET SOMETHING OTHER
THAN SPITS OR SPRINKLES ON FRIDAY BUT LIGHT NONETHELESS WITH THE
WARMING TREND CONTINUING. SEA FOG THREAT RETURNING LATE FRIDAY
AND SATURDAY. SATURDAY SHOULD BE VERY WARM WITH STRONG INVERSION
ALOFT AND SHALLOW LAYER BELOW THAT SHOULD WARM INTO THE MID TO
UPPER 70S FOR MOST AREAS. NEXT TROUGH IN THE SEQUENCE DEEPENING AS
IT MOVES INTO CA AND THEN TOWARD THE 4 CORNERS AREA SUNDAY
MORNING...IT BEGINS TO SHEAR SLOWLY BUT IMPRESSIVE MOISTURE IS
FORECAST TO SURGE BACK INTO THE AREA SUNDAY AND FUEL THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. GFS/ECMWF AND EVEN THE
NAM ALL ARE HIGHLIGHTING AN AREA OF STRONG TO SEVERE THUNDERSTORMS
LATE SUNDAY OVER THE NORTHEASTERN AREAS (MADISONVILLE TO CONROE TO
LIBERTY) FOR TORNADOES OR STRAIGHT LINE DAMAGING WINDS WHERE
STORMS GET AWAY FROM THE NOSE OF THE CAP THAT WILL INTRUDE INTO
THE AREA FROM THE SOUTHWEST (STRONG CAP IN THE SW AREAS). WILL
CONTINUE TO SHOW 30-50 POPS FOR NOW BUT MAY NEED A NUDGE UP AS IT
GETS CLOSER. QPF OF 0.25 TO 0.50 IS LIKELY OVER MUCH OF THE CWA
(EXCEPT PERHAPS SW COUNTIES) AND WOULDN`T BE SHOCKED IF FAST
MOVING STORM DUMP 1-3 INCHES IN THE NE COUNTIES. BLAST OF CANADIAN
AIR SWEEPS THROUGH WITH THE STORMS AND THE AREA SHOULD DRY OUT
MONDAY AND POSSIBLY TUESDAY UNLESS NEXT S/W IS STRONG ENOUGH TO
BRING BACK SOME LIGHT RAIN TO THE SOUTHERN AREA WITH GOOD UPGLIDE.
45

[ams30721us]

Uhm..anyone seen the 00z nam yet? Talk about a fun day of weather Sunday. The Nam would indicate the possibility of storms Sunday and winter precip, Sunday afternoon and evening in same areas. Temps go from upper 60s into 20s quickly in some areas! The 18z GFS also hinted at a chance for wintry precip on the backside of moisture.

[Srain]

A potent storm system currently offshore of California will advance inland on Saturday as it treks E on Sunday ahead of a deepening Central/Eastern US trough setting the stage for a potential severe weather episode on Sunday basically from Austin on E across SE and E Texas mainly N of I-10 where there are growing indications the capping inversion will erode. A very strong RRQ 110kt jet could allow for strong to severe storms to develop and quickly shift E into Louisiana Sunday afternoon/evening as a strong Polar front drops S. The Storm Prediction Center has placed a Day 3 Slight Risk for Severe Storms across potions of the Eastern half of Texas extending E into Louisiana to around Baton Rogue. The primary threat appears to be damaging straight line winds with some hail and a possible quick spin up of a tornado or two with the veering winds aloft.

The main concern is the strong cap and if it can erode and how quickly the Polar front arrives as suggested by the short term meso models. The severe threat looks a bit less S of I-10 this morning, but will need to be monitored as the storm system moves onshore tomorrow. The primary concern appears to be a squall line or linear storms -vs- rotating super cells, but if the cap does erode quicker across E Texas and Western Louisiana then some discrete rotating super cells may be possible Sunday afternoon.

Much colder air will arrive Sunday night with a possible freeze across our Northern zones early Monday. A very active pattern continues into mid next week as a Coastal Low develops Tuesday into Wednesday offering additional rain chances before we settle down and begin a slow warming trend by the end of next week.

[Quixotic1]

FWD AFD growing concerned about Icing potential.

[1900hurricane]

NAM solutions for Sunday look like outliers, but I'm afraid there may be some truth to its faster fropa/undercutting solution. Similar types of systems featuring arctic fronts happened (with notoriety) last April, and the NAM handled those much better than the rest of guidance. I'm not willing to abandon the general consensus at this point in the game, but the NAM solution needs to be watched.

Hopefully I'm just being pessimistic.

Sent from my iPhone using Tapatalk

[bubba hotep]

Ummm.... the 12z NAM would be a pretty significant icing event for some of the northern areas of DFW.  FWD has been leaning on the NAM a lot for this event in their discussions. This could get interesting

[Srain]

The SPC SREF is suggesting the potential of a rather significant ice event, if it is correct. These shallow Arctic air masses tend to give the guidance fits as we have seen all winter.

[1900hurricane]

After being quite optimistic for the past two days, I'm really beginning to sour with respect to tomorrow's severe weather possibilities. Models have tended a little stronger with the arctic cold front to the north, shrinking the warm sector and increasing the chances of undercutting surface-based storms. Additionally, guidance has trended towards the mid-level disturbance being of a lower amplitude, so now instead of being in the exit region of the upper jet streak rounding the base of the trough as well as in close proximity to the right entrance region of the streak traversing the baroclinic zone to the northeast, the two streaks will have merged, leaving east Texas within the cyclonicly curved right entrance region of the merged streaks. This could very well leave the warm sector capped right up until fropa, wasting the best dynamics for severe weather.

 

 

 

[DFWWeather]

Growing concerned of a rather significant icing event in the Metroplex, especially northern areas. Latest NAM suggests frontal passage at 3 am and rapid fall to below freezing by mid morning. NWS mentions QPF to be 1/4 to 1/3 of an inch QPF at DFW. We could be dealing with Winter Storm Warning criteria here. Question remains warm nose aloft at nearly 50°F would ensure most all precipitation to fall as freezing rain. If we could get the warm nose to cool and shrink and more sleet to fall this could be real interesting!