Southern Storm-January 23-26

[Srain]

The major weather headline will likely be the southern cut off low expect to drop S through the Southern Rockies early next week. The HPC has shown interests in this event and has tasked Winter RECON form HI and possibly from AK. The West continues active with a strong flow off the Pacific and changes across the NE Pacific suggest a deep trough and potent U/L energy developing. What remains to be seen is if we see some phasing of the northern jet and southern cut off low. Severe potential increases and future RECON data should iron out the guidance struggles. This event may well have a wide spread impact as it ejects NE.

NOUS42 KNHC 201815

WEATHER RECONNAISSANCE FLIGHTS

CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.

0115 PM EST FRI 20 JANUARY 2012

SUBJECT: WINTER STORM PLAN OF THE DAY (WSPOD)

VALID 21/1100Z TO 22/1100Z JANUARY 2012

WSPOD NUMBER.....11-051

I. ATLANTIC REQUIREMENTS

1. NEGATIVE RECONNAISSANCE REQUIREMENTS.

2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.

II. PACIFIC REQUIREMENTS

1. FLIGHT ONE -- NOAA 49

A. P56/ DROP 9 (44.3N 151.0W)/ 22/0000Z

B. NOAA9 04WSC TRACK56

C. 21/1930Z

D. 16 DROPS AS PUBLISHED ON TRACK

E. 41,000 TO 45,000 FT/ 22/0600Z

2. SUCCEEDING DAY OUTLOOK: POSSIBLE G-IV MISSION...

P38/ DROP 9 (34.5N 178.3E)/ 23/0000Z.

3. ADDITIONAL DAY OUTLOOK: POSSIBLE C-130J MISSION

FOR 24/0000Z.

SEF

[Srain]

Wet and stormy via the 00Z Canadian...

[Srain]

Concern grows that a heavy multi day rainfall event may be ahead as the cut off 5H low meaders across Texas. The GFS ensembles and HPC QPF progs suggest a very active and wet period is ahead as well as a Coastal Low developing along the Middle Texas Coast and training storms along a stalled boundary, setting the stage for possible flooding as well as severe storms with an isolated tornado or two as well. We'll need to monitor the meso models in the next several days and see just how wide spread the severe potential may be. My hunch is anywhere from Central Texas and points N and E will be under the gun for the severe side of this cyclone with very heavy rainfall potential for the eastern half of Texas extending E along the Central Gulf Coast and Lower Mississippi Valley regions.

[#NoPoles]

i'm one for big storms, but hoping the heavy precip stays in southern NM...if it snows on my work area again (it's just barely melted out enough to collect data on) then it will be another few weeks waiting for it to melt out...and then i won't be looking at a paycheck till March...that would be a huge diaster of epic proportions...but on the other hand, i'd love the ski resorts to get dumped on...and we do need the precip...whatever happens, happens...

[Srain]

The 12Z Canadian and Euro have trended to a slower ejection E of the deep closed core low in Mexico and suggest an very wet and stormy period ahead for Texas and points N and E.

[Ed Lizard]

The slowing of the upper low hints more and a more at a potential flood threat. Which, except for the flood threat itself, is perfect medicine for a state experiencing a major drought.

Utah.edu weather center GFS suggests the severe threat is minimal except the very beginning (and then generally South of I-10) and then when the upper low starts to kick out, and keeps it out of the Gulf South until the upper low starts moving.

Between then, forecast skew-Ts at various times show meager lapse rates but deep layer saturation, and Spring like preciptable water values. I don't know statistics, but PW in excess of 1.5 (near 1.7 inches at times) inches has got to be a lot of SDs above the mean in January for Houston.

[Ed Lizard]

Rough math that 40 mm is ballpark 1.5 inches TPW, one can see where the high forecast TPW could come from...

[baroclinic_instability]

It does seem the big story with this event will be the heavy rain. Much of the early DMC will be elevated above the surface front, and the stalled and even retrograding nature of the upper low will keep shear values on the low side. There may be some change, but it does seem all the global guidance misses the phase with the multiple northern stream shortwaves through day 4, so heavy precip definitely seems to be the story. Another drought buster is only a good thing.

[wxmx]

Drought buster indeed. Looks like most of the eastern half of TX will be out of the exceptional drought status after the event, except for deep S of the state. I can only imagine what would had happened with a 1050hp artic high over WY.

[Ellinwood]

Heavy rain is definitely the biggest concern with this system, but there is also a decent severe risk Tuesday evening into Wednesday morning (24th-25th) in central Texas. There is a cap in place around 750-800mb that will hinder strong warm-sector convection through most of the day on the 24th, but the upper-level vort. max should move in by the evening, providing enough lift to break the cap. The severe threat will go down beyond Wednesday morning once the upper-level low cuts off and the upper-level winds lose their westerly component. There is also some help from the low-level jet that is expected to form over central Texas, but the core of the jet is displaced eastward from the area of greatest instability, so I don't know just how much help it will be able to provide.

There could be some play for severe near the warm front as it lifts north Tuesday, but that's chancey considering the broad areal coverage of clouds and showers just south of the front. Mainly an elevated threat from that as hail tries to push through to the surface.

[Ed Lizard]

TIMING REMAINS VERY UNCERTAIN...AS THE CANADIAN

AND 12Z GFS ENSEMBLE MEANS SUGGEST THE BETTER CHANCE OF CONVECTIVE

RAINS TO BE SHIFTED LATER IN THE WEEK OR THURSDAY INTO FRIDAY.

WILL KEEP WITH A GFS/ECMWF BLEND AND KEEP HIGHEST POPS FOR

WEDNESDAY AS THE BETTER OVERRUNNING SIGNATURE SHOULD GENERATE

MEASURABLE RAINS FOR MOST AREAS...BUT NOT NECESSARILY THE HIGHEST

AMOUNTS SHOULD THE SLOWER MODEL TRACKS VERIFY. THE STORM TOTAL

RAINS COULD AGAIN APPROACH 2 INCHES FOR SOME AREAS...BUT THE RUN-

TO-RUN TRENDS GENERALLY SLOWING DOWN...THERE COULD BE AN

INCREASING POTENTIAL FOR THE CUT-OFF DISTURBANCE TO DRIFT FARTHER

SOUTH AND WEAKEN...LEAVING SOUTH TX DRIER THAN ADVERTISED. THUS A

MORE REASONABLE EXPECTATION OF MID WEEK RAINS SHOULD BE IN THE

NEIGHBORHOOD OF 1/4 TO 1/2 INCH.

The Euro has been on a slow ejection/cut-off scenario, and the 120 hour Euro ensemble means have excellent agreement with the operational. The ensemble Euro misses only the cut-off low, but when various runs are averaged together, a missed final set of closed height contours isn't big, and the surrounding 5760 meter height lne between the ensembles and the operational are almost identically positioned.

That should give some confidence in the Euro solution, over an inch of rain Wednesday alone per the MOS for Austin. Slight later start and end, Wednesday morning to early Thursday morning, but better than an inch and a half for Houston.

EWX may wind up being right, on the low wandering so far West of Texas as it cuts off to be only a trivial rain event, but I'd bet the over on their rainfall.

of course, the EWX CWA extends Westward to the Mexican border, but even Del Rio gets over half an inch per Euro output.

[Ed Lizard]

Holy freaky deep layer saturated soundings, Batman!!!

[Ed Lizard]

Trying to figure out why, at 84 hours, the Canadian nukes West Texas, while the GFS drops the bomb much closer IMBY. The only obvious difference I see if the Canadian is more compact in its closed low.

[My Weather Today]

FWIW, here's the HPC's latest thoughts on this system...

PRELIMINARY EXTENDED FORECAST DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD

305 AM EST SUN JAN 22 2012

VALID 12Z THU JAN 26 2012 - 12Z SUN JAN 29 2012

INCREASED RIDGING ACROSS THE EASTERN PACIFIC SHOULD ALLOW FOR

TROUGHING TO STICK AROUND ACROSS THE PLAINS/MIDWEST THROUGH THE

PERIOD UNDER A PORTION OF THE POLAR VORTEX DEVELOPING ACROSS

CENTRAL CANADA NEXT WEEKEND. THE GUIDANCE AGREES ON THIS IDEA.

HOWEVER...THERE ARE A COUPLE LARGE ISSUES. THE 00Z GFS/00Z GEFS

MEAN AGGRESSIVELY KNOCK DOWN THE TOP OF THE RIDGE ACROSS THE

WESTERN SUBTROPICAL ATLANTIC...WHICH ALLOWS A MUCH QUICKER FRONTAL

PROGRESSION IN THE EAST. THE LONGWAVE TROUGH ACROSS MID-CONTINENT

FAVORS RIDGING IN THE WESTERN ATLANTIC...SO DISCOUNTED THE 00Z

GFS/00Z GEFS MEAN FOR MOST OF THE PERIOD.

THE OTHER BIG ISSUE IS HOW TO HANDLE THE SOUTHERN STREAM CLOSED

LOW NEAR TEXAS ON WEDNESDAY. THE 00Z ECMWF IS NOW THE QUICKEST OF

THE GUIDANCE /SIMILAR TO THE 00Z GFS A COUPLE DAYS AGO/ WHILE THE

00Z GEFS MEAN IS THE SLOWEST /SIMILAR TO THE 00Z ECMWF A COUPLE

DAYS AGO/. THE 12Z GLOBAL ENSEMBLE SPREAD WITH THIS SYSTEM

COVERED A VAST AMOUNT OF REAL ESTATE...WITH SOLUTIONS BETWEEN

CENTRAL BAJA CALIFORNIA AND THE NORTHEAST UNITED STATES ON

FRIDAY...PLACING THE 00Z ECMWF ON THE QUICK SIDE OF THE SPREAD.

THE 00Z GFS/00Z UKMET MAKE FOR A NICE MIDDLE OF THE ROAD SOLUTION

HERE...BUT THE 00Z ECMWF HAS TOO MUCH ENSEMBLE SUPPORT TO BE

IGNORED.

DUE TO THE ABOVE...USED A 00Z UKMET/00Z GFS/00Z ECMWF COMPROMISE

SOLUTION WEDNESDAY BEFORE SWITCHING TO A 00Z UKMET/00Z ECMWF/12Z

ECMWF ENSEMBLE MEAN COMPROMISE THURSDAY AND FRIDAY AND A SIMPLER

00Z ECMWF/12Z ECMWF ENSEMBLE MEAN BLEND NEXT WEEKEND. THIS SHOULD

ACCOUNT FOR SOME OF THE UNCERTAINTY IN THIS LOW CONFIDENCE

FORECAST AND MAINTAIN SOME FORM OF CONTINUITY.

ROTH

[Srain]

Some thoughts this morning before the 12Z suite comes out. The Euro is a bit too progressive and is considered an outlier as is the Canadian. A slower ejection E of the U/L has been the pattern all season. There remain some questions as to the amount of phasing with the northern stream short wave and how that will affect our southern cyclone. The data gain from the RECON mission 22/00Z aided the 00Z GFS/NAM/Euro output and was ingested as that mission covered a large area from HI to AK, W of the Pacific NW/CA Coast. The GFS/UKMet blend with a bit of Euro early on seems like the best solution for now and the HPC mentions that in their very early morning update. I do want to mention the severe potential as well. The day 3 SPC is talking about an isolated tornado or two for S Texas as the Coastal low develops and slowly translates NE up the Coast. As has been mentioned, the atmosphere will be very moist through all levels in a very un January fashion. The Sunday front will slowly retreat N and just where that boundary stalls will be key. We'll look at the operational data for the 12Z suite and hopefully have some more details as to what we can expect. I encourage everyone to follow the weather very closely the next several days as we are likely headed toward a very active couple of days beginning Tuesday through Thursday.

[Srain]

HPC Morning Update:

PRELIMINARY EXTENDED FORECAST DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD

859 AM EST SUN JAN 22 2012

VALID 12Z THU JAN 26 2012 - 12Z SUN JAN 29 2012

INCREASED RIDGING OVER THE ERN PACIFIC THIS WEEK SHOULD ALLOW FOR

MEAN TROUGHING TO STICK AROUND OVER THE PLAINS/MIDWEST UNDER A

PORTION OF THE POLAR VORTEX DEVELOPING OVER CENTRAL CANADA NEXT

WEEKEND. GUIDANCE AGREES ON THIS IDEA...BUT THERE ARE A COUPLE

LARGE ISSUES.

THE 00Z GFS/00Z GEFS MEAN MORE AGGRESSIVELY KNOCK DOWN THE TOP OF

THE RIDGE OVER THE WRN SUBTROPICAL ATLANTIC BY FRI THAN OTHER

GUIDANCE..WHICH ALLOWS A QUICKER FRONTAL PROGRESSION IN THE EAST.

THE LONGWAVE TROF OVER MID-CONTINENT FAVORS GRADUAL WRN ATLANTIC

RIDGE WEAKENING. THE OTHER BIG ISSUE IS HOW TO HANDLE THE

SOUTHERN STREAM CLOSED LOW NEAR TEXAS WED. 00Z ECMWF/ECMWF

ENSEMBLES ARE NOW THE QUICKEST OF THE GUIDANCE WHILE THE 00Z GEFS

MEAN/NOGAPS ARE THE SLOWEST. FORECAST SPREAD WITH THIS SYSTEM IS

SIGNIFICANT...WITH SOLUTIONS RANGING BETWEEN NRN MEXICO AND THE

EAST COAST BY FRIDAY DEPENDING ON THE EXTENT OF NRN STREAM

INTERACTION. THE 00Z GFS/UKMET AND TO A SLIGHTLY LESSER DEGREE

THE 00Z CANADIAN AND 06Z GFS/DGEX ARE ON THE SLOW SIDE OF THE

SOLUTION ENVELOPE...BUT NOT AS SLOW AS THE MOST EXTREME CUTOFF

SOLUTIONS. CLOSED LOWS IN A SEPARATED SRN STREAM TEND TO REMAIN

ON THE SLOW SIDE SO WILL DISCOUNT THE 00Z ECMWF THAT ALSO OFFERS

POOR RUN TO RUN CONSISTENCY. UNCERTAINTY THOUGH PROBABLY MAKES IT

PRUDENT TO NOT GO WITH THE SLOWEST GEFS ENSEMBLES/NOGAPS.

ACCORDINGLY...UPDATED HPC PRELIM PROGS HAVE BEEN PRIMARILY DERIVED

FROM A 50-50 BLEND OF THE 00Z GFS/UKMET DAYS 3-5 WED-FRI BEFORE

LEANING ON THE 00Z GFS NEXT WEEKEND...ALBEIT WITH LESS PRONOUNCED

EAST COAST/WRN ATLANTIC CYCLOGENSIS CONSIDERING UNCERTAIN SUPPORT

ALOFT.

[ohleary]

WSR to directly target the southern stream storm didn't look like a good candidate, as by 1/24 00Z the short wave is already over the west coast. Noting that the evolution of the entire system is dependent on the northern stream feature (and how it evolves for the East US), tasked the C-130 to target this on 24/00Z...it looks to have a positive impact on the northern stream shortwave on 26/00Z.

[Srain]

WSR to directly target the southern stream storm didn't look like a good candidate, as by 1/24 00Z the short wave is already over the west coast. Noting that the evolution of the entire system is dependent on the northern stream feature (and how it evolves for the East US), tasked the C-130 to target this on 24/00Z...it looks to have a positive impact on the northern stream shortwave on 26/00Z.

Thanks for the update, ohleary. The 22/00Z WSR certainly helped with some clarification of the evolution of the southern cyclone and some impressive totals are suggested with that slow moving U/L...

[Srain]

The 12Z Canadian remains slow in ejecting the U/L from Mexico/W Texas and suggests copious rainfall/storms across Texas and point N and E...

[Srain]

DAY 2 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1258 AM CST MON JAN 23 2012

VALID 241200Z - 251200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF CENTRAL AND

SRN TX...

...SYNOPSIS...

AS A NRN STREAM UPPER TROUGH CONTINUES EWD ACROSS ERN CANADA AND THE

NERN U.S. THIS PERIOD...A SECOND TROUGH OVER THE DESERT SW IS

FORECAST TO MOVE SLOWLY EWD ACROSS THE SRN ROCKIES AND INTO THE SRN

PLAINS.

AT THE SURFACE...A COLD FRONT ASSOCIATED WITH THE NERN U.S. TROUGH

SHOULD BE SHIFTING OFF THE NEW ENGLAND AND MID-ATLANTIC COASTS AT

THE START OF THE PERIOD...BUT WILL LAG WSWWD/WWD ACROSS THE GULF

COAST REGION. ALONG THE WRN FRINGE OF THIS BOUNDARY -- I.E. INVOF

THE RIO GRANDE...EXPECT THE UPPER TROUGH APPROACHING THE S CENTRAL

CONUS TO DRIVE FRONTAL CYCLOGENESIS -- WITH A WEAK LOW MOVING

INTO/ACROSS S TX THROUGH THE END OF THE PERIOD.

...CENTRAL AND SRN TX...

SELY LOW-LEVEL FETCH OFF THE GULF OF MEXICO WILL SUPPORT

BOUNDARY-LAYER MOISTENING ACROSS TX THIS PERIOD...WITH 50S DEWPOINTS

REACHING AS FAR NWWD AS THE TRANSPECOS REGION AND TX S PLAINS.

WHILE WEAK ELEVATED INSTABILITY AND LOW-LEVEL WARM ADVECTION WILL

LIKELY SUPPORT CONVECTIVE DEVELOPMENT ACROSS CENTRAL AND N TX

EARLY...LITTLE SEVERE THREAT IS EVIDENT WITHIN THIS REGIME.

HOWEVER...AS COOLING ALOFT ASSOCIATED WITH THE UPPER TROUGH

OVERSPREADS THE MOISTENING BOUNDARY LAYER...AN ENVIRONMENT

THERMODYNAMICALLY SUPPORTIVE OF MORE ROBUST/SURFACE-BASED CONVECTION

WILL EVOLVE. AFTERNOON CONVECTIVE DEVELOPMENT SHOULD OCCUR -- AIDED

BY LARGE-SCALE UVV IN ADVANCE OF THE UPPER SYSTEM -- E OF THE

TRANSPECOS REGION INTO PORTIONS OF CENTRAL TX. WITH SHEAR

SUFFICIENT FOR ORGANIZED/SUPERCELL STORMS...THREAT FOR ISOLATED

DAMAGING WINDS AND HAIL -- AND POSSIBLY A TORNADO -- SUPPORTS

INCLUSION OF SLIGHT RISK ACROSS THIS AREA.

THE SLIGHT RISK WILL ALSO BE EXTENDED EWD TO THE MIDDLE TX

COAST...WHERE EARLIER/SLIGHTLY ELEVATED CONVECTION WHICH WILL LIKELY

HAVE SHIFTED NWD MAY BE REPLACED BY ISOLATED/SURFACE-BASED STORMS AS

THE SURFACE LOW DEVELOPS ESEWD. HERE...ISOLATED STRONG GUSTS AND A

TORNADO OR TWO MAY ACCOMPANY A FEW STRONGER/ROTATING CELLS THROUGH

THE END OF THE PERIOD.

[Srain]

Our storm is approaching the West Coast this morning with Winter Storm Warnings for the Sierra Nevada Range and Winter Storm Watches N Nevada, Utah and for the higher elevations of Arizona...Winter Weather Adivisories may be issued later today for New Mexico as well...

[Srain]

Morning e-mail from Jeff:

Highly active storm system will move into to Texas mid week to produce the threat for severe weather and excessive rainfall.

Short Term (Today-Tuesday AM):

Pacific cold front responsible for the massive western TX wind/dust event yesterday is pushing off the coast this morning with a much drier air mass building into the nearshore waters ending the sea fog that has plagued the area since last Friday. NW winds today will help push drier NC TX air mass into the region, but this will be short lived as the central US high pressure cell moves quickly eastward and low pressure develops in the lee of the southern Rockies. Winds will turn east by late tonight with clouds increasing.

Tuesday Afternoon-Wednesday Afternoon:

Severe weather and heavy rainfall possible.

Powerful upper level trough will drop into northern Mexico which in turn forces downstream pressure falls over southern TX early Tuesday. Surface low pressure will develop across the SW Rio Grande plains and help promote a rapidly intensifying low level jet across TX from the western Gulf toward DFW. Models are in agreement that the low level jet will increase to near 40kts by Tuesday afternoon pumping copious Gulf moisture from the western Gulf into the coastal bend and then northward into central and SE TX. Old frontal boundary offshore from today will retreat northward as a warm front. Combination of this boundary, increasing large scale ascent from the upper level storm, and strong warm air advection regime all point to showers/thunderstorms developing near/north of this boundary on Tuesday. Forecast models show low level winds backing during the afternoon toward the ESE while mid level WSW flow increases…this will begin to create favorable low level turning of winds. Current thinking is that instability will be limited, but given the strong low level shear that will be developing supercell structures may begin to develop within northward moving cells off the Gulf.

Entire area should become warm sectored by Tuesday evening, but showers and thunderstorms will continue to stream northward out of the Gulf of Mexico in SSW to NNE lines. Cold front and main lift will begin to impinge on the area after midnight along with favorable jet dynamics as the upper low wobbles into western TX. Expect a line of strong thunderstorms to move ESE out of central TX into very favorable low level inflow. Main concern overnight into Wednesday morning will be the threat for supercells moving northward out of the Gulf and embedded supercells in the main line approaching from the west. These cells will have the threat to produce low level rotation and possible tornadoes. Low LCL’s and high moisture levels will result in very low cloud bases and any tornadoes will likely be wrapped in rain. Warning lead times in these sort of situations tend to be lower than average and heavily radar based. All severe modes will be possible: large hail, damaging winds, and tornadoes from late Tuesday through early afternoon Wednesday. SPC has outlooked a large part of the coastal bend, SE TX, and central TX for severe thunderstorms (see attached map below).

Surface low stretches out to the northeast Tuesday night while strong low level jet remains anchored off the western Gulf pumping rich moisture northward. PWS increase to 1.46 in on the GFS by early Wednesday morning and near 1.55 in by Wednesday midday which is nearing the 99th percentile and +2 SD for late January moisture levels. This high moisture combined with the threat for storm cells to become parallel to the mean steering wind flow raises an excessive rainfall/flash flood red flag. Other potential will be for large supercells to slow/anchor in the strong low level flow producing extremely high rainfall rates in a very short period of time. Air mass will be capable of some 2-3 inch per hour rainfall rates which can create problems very quickly in urban areas. Expect widespread 1-2 inches of rainfall with isolated totals of 3-5 inches. Main axis of excessive rainfall currently appears to focus along and north of a line from Victoria to Conroe to Lufkin, but any southward shift in this axis would bring the core of the excessive rainfall along the US 59 corridor and into the more urban areas. As noted with the 1-9-12 event high short term rainfall rates can result in significant street flooding in a very short period of time. DO NOT drive into high water!

Long Term (Wednesday night-Friday)

Upper level storm system will slowly progress across the state, but the main trigger for showers and thunderstorms should move eastward into Louisiana by early Wednesday evening. Cold front will move off the coast at this point and while a few showers may linger into Thursday and severe and heavy rainfall threat will be over. Colder air mass will filter southward and the GFS model is showing a period of trapped low level moisture under the frontal inversion leading to possibly an extended period of low level clouds. May not see any sun on Thursday which will keep highs on the colder side. Should see the low level deck break out on Friday, but I am sometimes wary of moisture trapped under the frontal inversion as it can be difficult to scour out the low clouds.

[Srain]

HPC Model Diagnostics Discussion:

...INITIAL WEST COAST TROF/CLOSED LOW OVER TEXAS BY THU...

PREFERENCE: GFS/ECMWF COMPROMISE

THE NAM/GFS AND OTHER OPERATIONAL MODELS HAD PROVIDED DECENT

STRENGTH/TRACK/TIMING AGREEMENT THRU THE PERIOD. HOWEVER THE

UKMET NOW STRAYS FASTER THAN CONSENSUS LATE IN THE PERIOD DUE TO A

MORE AMPLIFIED NRN STREAM TROF THAT BEGINS TO INTERACT WITH THE

SYSTEM OF INTEREST... WHILE THE CANADIAN GLBL TRENDS SWWD OF THE

MAJORITY MODEL CLUSTER BY WED-THU. 06Z GEFS/09Z-12Z SREF MEANS

ALSO REMAIN ON THE SLOW SIDE OF THE ENVELOPE AND TRENDS OVER THE

PAST DAY DO NOT FAVOR THE SLOWER SOLNS. THE 12Z ECMWF ADJUSTS A

LITTLE SLOWER BY THU BUT IS STILL IN DECENT AGREEMENT WITH THE

NAM/GFS. IN SPITE OF REASONABLE COMPARISON OF THE NAM MID LVL

FCST TO OTHER MDLS... ITS SFC SYSTEM BY THE LATTER HALF OF THE

PERIOD IS WEAKER EXCEPT FOR THE CMC AND 09Z SREF/06Z-12Z GEFS

MEANS WHICH ARE QUESTIONABLY WEAKER AND/OR SLOWER ALOFT. PREFER A

GFS/ECMWF COMPROMISE TO REFLECT THE MOST COMMON IDEAS OF

OPERATIONAL GUIDANCE SFC/ALOFT WITH INTERMEDIATE TIMING.

CONFIDENCE IS AVERAGE.

[My Weather Today]

Here's a good discussion out of Austin regarding this event...

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX

320 PM CST MON JAN 23 2012

.DISCUSSION...

ANOTHER CUT-OFF LOW TO PROMOTE EXCELLENT RAIN CHANCES ACROSS MUCH

OF SOUTH CENTRAL TEXAS TUESDAY NIGHT THROUGH WEDNESDAY. SIMILAR TO

THE UPPER LOW PATTERN WHICH OCCURRED ON MONDAY...JAN 9...THIS

UPPER LOW HAS A SURROUNDING ENVIRONMENT OF STABLE AND DRY PACIFIC

AIR EXPECTED TO WRAP AROUND IT AS IT MOVES INTO SOUTH CENTRAL

TEXAS. HOWEVER...COMPARISON OF THE FORECAST UPPER LOW FOR EARLY

WEDNESDAY VERSUS THE ONE THAT MOVED THROUGH ON JAN 9 SHOWS A

SIMILAR SIZE BUT MORE N-S ORIENTATION FOR THE UPCOMING LOW INSTEAD

OF A MORE CIRCULAR AND SLIGHTLY E-W ORIENTATION OF THE JAN 9 LOW.

THUS AM EXPECTING AN INCREASED POTENTIAL FOR A NEAR SOLID COMPLEX OF

RAIN TO DEVELOP EARLY WEDNESDAY MORNING OVER THE WESTERN COUNTIES

AND DRAGGING EASTWARD ACROSS THE EASTERN TWO THIRDS OF THE AREA.

THIS SHOULD HOPEFULLY YEILD A BIT MORE RAIN OVER THE CENTRAL

COUNTIES AS COMPARED TO THE EVENT FROM JAN 9.

ANOTHER DIFFERENCE IS THAT THIS N-S ORIENTED FOCUS FOR RAIN

SHOULD RESULT IN STRONGER CONVERGENCE ALONG THE N-S AXIS TO

PROMOTE STRONGER STORMS AND POSSIBLY SOME WIND DAMAGE OR EVEN A

WEAK TORNADO. HIGHEST HELICITIES SHOLD BE EXPECTED TO OCCUR S/SE

OF SAT SOME SOME MODEL DATA SHOWING VALUES OF 300 M2/S2. THE

THREAT FOR HIGH WINDS SHOULD BE LESS OVER WESTERN COUNTIES...BUT

EVENING TIMING OF CONVECTION AND COLDER AIR ADVECTION ALOFT FROM

THE UPPER LOW COULD SUPPORT A FEW HAIL STORMS. OVERALL THE

OVERNIGHT/DAYBREAK TIMING OF A WINTER EVENT SHOULD MEAN A MARGINAL

SEVERE THREAT ACROSS NEARLY ALL OF SOUTH CENTRAL TX. IN ADDITION

TO THE SEVERE POTENTIAL...CUMULATIVE RAINS ALONG AND EAST OF

HIGHWAY 281 COULD APPROACH 2 INCHES...WITH HIGHER AMOUNTS OVER 3

INCHES POSSIBLE IN THE COUNTIES EAST OF A AUSTIN TO CUERO LINE.

WITH THE HIGHEST CONVECTIVE POTENTIAL EXPECTED TO REACH THE I-35

CORRIDOR AROUND DAYBREAK WEDNESDAY...POPS ARE EXPECTED TO TAPER

QUICKLY FROM WEST TO EAST DURING THE DAY WEDNESDAY...WITH COOLER

AND MORE STABLE AIR LOWERING RAIN POTENTIAL OVER THE AREA DESPITE

THE UPPER LOW BEING OVERHEAD. THE WEATHER IN THIS PERIOD FROM LATE

IN THE DAY WEDNESDAY THROUGH THURSDAY SHOULD BE SIMILAR TO THAT OF

JAN 9-10 WITH COLD AND MOIST AIR MOVING SOUTH WHILE CLOUDS REMAIN

ABUNDANT. MODELS SHOW SOME WRAP-AROUND RAINS TO POSSIBLY AFFECT

OUR NORTHERN COUNTIES THROUGH THURSDAY...BUT WILL DOWNPLAY THIS

EFFECT AND FAVOR THE DRIER NAM OVER THE WETTER GFS.

AFTER THE LOW MOVES WELL TO THE EAST FRIDAY...A MILD DAY WITH

LIGHT WINDS COULD SUPPORT A FOG PATTERN...BUT WILL LEAVE THIS OUT

OF THE FORECAST FOR NOW DUE TO MOSTLY NORTH WINDS FRIDAY MORNING.

ON SATURDAY A STRONG FRONTAL PUSH IS EXPECTED...AND WILL EXPECT TO

SEE A FEW SITES HIT FREEZING SUNDAY MORNING. THE CONSENSUS PATTERN

FOR EARLY NEXT WEEK SHOWS MORE PROGRESSIVE ZONAL FLOW ALOFT WITH

POSSIBLY A RETURN TO MORE NORMAL TO ABOVE NORMAL TEMPERATURES AND

DRY WEATHER.

[Srain]

URGENT - WINTER WEATHER MESSAGE

NATIONAL WEATHER SERVICE ALBUQUERQUE NM

358 PM MST MON JAN 23 2012

...ACCUMULATING SNOW ACROSS PARTS OF NORTHWEST AND WEST CENTRAL NEW

MEXICO LATE THIS EVENING THROUGH TUESDAY...

.A DEVELOPING STORM SYSTEM OVER THE GREAT BASIN LATE THIS

AFTERNOON WILL CROSS NEW MEXICO TONIGHT AND TUESDAY WITH A FEW TO

SEVERAL INCHES OF SNOW ACCUMULATION ACROSS THE NORTHWEST

MOUNTAINS...NORTHWEST HIGHLANDS AND WEST CENTRAL MOUNTAINS.

LIGHTER AMOUNTS ARE EXPECTED AT LOWER ELEVATIONS...ESPECIALLY NEAR

THE COLORADO AND ARIZONA BORDERS. RAIN AND SNOW SHOWERS EARLY THIS

EVENING WILL CHANGE OVER TO ALL SNOW BY LATE EVENING...THEN

SNOWFALL WILL BECOME HEAVIER LATE TONIGHT AND EARLY TUESDAY

MORNING...BEFORE DIMINISHING FROM WEST TO EAST TUESDAY AFTERNOON.

FOR THE LATEST ROAD CONDITIONS IN NEW MEXICO DIAL 511 VIA

TELEPHONE...OR OVER THE INTERNET VISIT M.NMROADS.COM.

NMZ502>504-506-510-511-240600-

/O.NEW.KABQ.WW.Y.0004.120124T0400Z-120125T0000Z/

CHUSKA MOUNTAINS-FAR NORTHWEST HIGHLANDS-NORTHWEST HIGHLANDS-

WEST CENTRAL MOUNTAINS-SAN JUAN MOUNTAINS-JEMEZ MOUNTAINS-

358 PM MST MON JAN 23 2012

...WINTER WEATHER ADVISORY IN EFFECT FROM 9 PM THIS EVENING TO

5 PM MST TUESDAY...

THE NATIONAL WEATHER SERVICE IN ALBUQUERQUE HAS ISSUED A WINTER

WEATHER ADVISORY FOR SNOW...WHICH IS IN EFFECT FROM 9 PM THIS EVENING

TO 5 PM MST TUESDAY.

* SNOW ACCUMULATIONS...2 TO 5 INCHES...EXCEPT 3 TO 6 INCHES ABOVE

7500 FEET. LOCALLY AROUND 8 INCHES WILL BE POSSIBLE IN THE

MOUNTAINS ON WEST AND SOUTHWEST FACING SLOPES.

* TIMING...RAIN AND SNOW SHOWERS EARLY THIS EVENING WILL CHANGE

OVER TO ALL SNOW LATE THIS EVENING AS A COLD FRONT ARRIVES.

PERIODS OF MODERATE TO HEAVY SNOW WILL OCCUR LATE TONIGHT AND

EARLY TUESDAY MORNING. SNOW WILL THEN DIMINISH FROM WEST TO EAST

TUESDAY AFTERNOON.

* WINDS...SOUTH AND SOUTHWEST AT SPEEDS FROM 10 TO 20 MPH ABOVE

7500 FEET THIS EVENING...WITH LIGHTER SPEEDS AT LOWER

ELEVATIONS. DIRECTIONS WILL SHIFT OUT OF THE NORTHWEST BY LATE

TONIGHT...THEN OUT OF THE NORTH WITH SPEEDS FROM 10 TO 15 MPH ON

TUESDAY.

* SNOW LEVELS...DROPPING FROM AROUND 7500 FEET EARLY IN THE

EVENING TO THE LOWEST ELEVATIONS AROUND MIDNIGHT. THEN...LIFTING

TO AROUND 7000 FEET AS THE PRECIPITATION ENDS TUESDAY AFTERNOON.

* LOCAL IMPACTS...ROADS WILL BECOME SNOW PACKED AND ICY. TRAVEL

MAY BECOME HAZARDOUS...ESPECIALLY THROUGH THE MOUNTAINS.

[Ed Lizard]

A lof of the modelling, including the 3Z SREFs, are ok for Houston, but save the build an ark type precip totals North and West of the local HOU area.

Looking at the NAM and 3Z SREFs, yeah, even the GFS, I'd say ballpark 1 inch locally, and better the farther North or West one goes. I-35 being the rough bullseye.

0Z and 0Z GFS similar in that respect.

[Srain]

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0703 AM CST TUE JAN 24 2012

VALID 241300Z - 251200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF SW...S

CNTRL...AND E CNTRL TX...

...SYNOPSIS...

UPR TROUGH NOW ON THE AZ-NM BORDER EXPECTED TO CONTINUE E OR ESE

TODAY...EVOLVING INTO A CLOSED LOW OVER FAR W TX BY EVE. THE SYSTEM

SHOULD BECOME FURTHER REMOVED FROM THE MAIN BELT OF THE WLYS EARLY

WED...AND CONTINUE SLOWLY ESE TO THE TX BIG BEND.

APPROACH OF UPR SYSTEM WILL MAINTAIN/ENHANCE BROAD AREA OF LOW LVL

CYCLOGENESIS ALREADY IN PROGRESS OVER ERN NM/W TX. THIS LOW SHOULD

GRADUALLY REFORM/CONSOLIDATE SEWD ALONG OR JUST S OF THE RIO GRANDE

THROUGH THE PERIOD...MAINTAINING E TO SELY SFC FLOW OVER MUCH OF TX.

INCREASING MOISTURE...LOW LVL CONVERGENCE...AND UPLIFT IN THIS

PATTERN WILL LEAD TO FAIRLY WIDESPREAD SHOWER AND TSTM DEVELOPMENT

LATER TODAY AND TNGT OVER THE SRN PLNS...ALONG AND N OF SLOWLY

ADVANCING W-E WARM FRONT NOW OVER DEEP S TX. SOME OF THE

STORMS...ESPECIALLY THOSE OCCURRING THIS EVE THROUGH EARLY WED FROM

S CNTRL THROUGH E CNTRL TX...COULD BECOME SVR.

...TRANS PECOS/PERMIAN BASIN THROUGH S CNTRL TX/HILL COUNTRY TO THE

TX CSTL PLN TODAY THROUGH EARLY WED...

INCREASING SFC TO 850 MB MOISTURE INFLOW AND UPLIFT ALONG AND N OF

AFOREMENTIONED WARM FRONT SHOULD RESULT IN SCTD AREAS OF MAINLY

ELEVATED STORMS OVER PARTS AND CNTRL AND E TX TODAY...WITH WARM

LAYER ALOFT PROHIBITING DEVELOPMENT IN WARM SECTOR OVER S TX. WHILE

ONE OR TWO OF THE STORMS COULD BECOME STRONG...RELATIVELY MODEST

WIND FIELD AND ELEVATED NATURE OF MOST OF THE ACTIVITY SHOULD LIMIT

SVR THREAT.

A MORE SUBSTANTIAL SVR RISK MAY EVOLVE VERY LATE THIS AFTN OR...MORE

LIKELY...EARLY THIS EVE FROM ERN PARTS OF THE PERMIAN BASIN S/SE TO

THE TX BIG BEND. COMBINATION OF HEIGHT FALLS/MID LVL COOLING

ASSOCIATED WITH APPROACHING UPR LOW...AND DAYTIME HEATING...SHOULD

FOSTER STORM DEVELOPMENT ALONG N-S LEE TROUGH/DRY LINE. WIND

PROFILES AND THERMODYNAMICS COULD SUPPORT A FEW SUPERCELLS CAPABLE

OF LARGE HAIL...LOCALLY DMGG WIND...AND POSSIBLY A COUPLE TORNADOES.

THE DRY LINE/LEE TROUGH STORMS SHOULD INCREASE IN COVERAGE THROUGH

EARLY WED AS UPR SYSTEM CONTINUES EWD. THE STORMS LIKELY WILL

EVOLVE INTO AN EXTENSIVE...LOOSELY-ORGANIZED SSW-NNE SQLN.

INCREASING...NEARLY MERIDIONAL 50-70 KT MID AND UPR LVL

FLOW...STRENGTHENING UPR DIVERGENCE...AND CONTINUED INFLOW OF VERY

MOIST AIR /PW AOA 1.50 INCHES/...WILL ENCOURAGE DEVELOPMENT OF

EMBEDDED LEWPS AND ROTATING STORMS. AT THE SAME TIME...PERSISTENT

ELY COMPONENT TO THE NEAR-SFC WINDS MAY SUPPORT DEVELOPMENT OF

LOW-LVL MESOCYCLONES. THIS ACTIVITY COULD YIELD AN INCREASING RISK

FOR DMGG WIND AND TORNADOES...IN ADDITION TO HEAVY RAIN...THROUGH

12Z WED.

[Srain]

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1023 AM CST TUE JAN 24 2012

VALID 241630Z - 251200Z

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON THROUGH TONIGHT

ACROSS CNTRL AND SRN PARTS OF TX...

...SYNOPSIS...

MID- TO UPPER-LEVEL TROUGH FROM THE CNTRL/SRN ROCKIES INTO NWRN

MEXICO WILL EVOLVE INTO A CLOSED CIRCULATION AS THE SYSTEM

TRANSLATES SLOWLY ESEWD INTO THE LOWER RIO GRANDE VALLEY. AT THE

SURFACE...LOW PRESSURE OVER FAR WRN TX WILL CONCURRENTLY DEVELOP

SEWD...EVENTUALLY JOINING WITH A WARM FRONT LIFTING NWD/NWWD FROM

DEEP S TX INTO THE CNTRL PART OF THE STATE. A DRYLINE WILL ALSO

ATTEND THE MIGRATORY SURFACE CYCLONE AS IT MOVES THROUGH SWRN TX.

...TX...

THE 12Z CRP SOUNDING SHOWED THE PRESENCE OF A DEEP MOIST LAYER

BENEATH AN EML...CHARACTERIZED BY BOUNDARY LAYER DEWPOINTS IN UPPER

60S TO LOWER 70S AND A 100-MB MEAN MIXING RATIO OF 14 G/KG. THE

LOW-LEVEL MASS RESPONSE TO THE APPROACH OF THE ABOVE-MENTIONED

UPPER-LEVEL TROUGH /MANIFEST IN THE DEVELOPMENT OF A 30-40 KT LLJ/

WILL ENHANCE THE NWD FLUX OF THIS MOIST AIR MASS...AND THE NWD

PROGRESSION OF THE SURFACE WARM FRONT. LOW-LEVEL WAA AND ISENTROPIC

ASCENT TO THE N OF WARM FRONT WILL RESULT IN THE DEVELOPMENT OF

SCATTERED TO NUMEROUS ELEVATED TSTMS TODAY...ALONG NRN EDGE OF

STRONGER CAPPING ASSOCIATED WITH THE EML. THE STRONGEST STORMS WILL

BE CAPABLE OF SEVERE HAIL GIVEN THE PRESENCE OF THE STEEP MIDLEVEL

LAPSE RATES AND INCREASING LOW-LEVEL MOISTURE.

MODIFICATION OF 12Z CRP SOUNDING FOR SURFACE TEMPERATURES OF AROUND

80 F SUGGEST THAT THE CAP WILL WEAKEN SUFFICIENTLY SUCH THAT

ISOLATED SURFACE-BASED STORMS WILL BE POSSIBLE BY MID LATE AFTERNOON

INVOF RETREATING WARM FRONT WITHIN AN ENVIRONMENT FEATURING MLCAPE

OF 500-1000 J/KG AND A VERTICALLY VEERING WIND PROFILE WITH 40-50 KT

OF WSWLY DEEP-LAYER SHEAR. SHOULD STORMS DEVELOP AND BECOME

SUSTAINED...A RISK FOR SUPERCELLS CAPABLE OF A TORNADO OR

TWO...DAMAGING WINDS AND SEVERE HAIL WILL EXIST.

A MORE SUBSTANTIAL SEVERE WEATHER THREAT IS NOT EXPECTED TO

MATERIALIZE UNTIL THIS EVENING NEAR THE INTERSECTION OF THE WARM

FRONT AND DRYLINE OVER PORTIONS OF THE CONCHO VALLEY INTO EDWARDS

PLATEAU. HERE...INCREASING HEIGHT FALLS/DYNAMIC FORCING FOR ASCENT

WILL OVERSPREAD THE NWWD-DEVELOPING WARM SECTOR...FOSTERING

SUPERCELLS AND BOWING STRUCTURES CAPABLE OF LARGE HAIL /SOME

POTENTIALLY SIGNIFICANT/...DAMAGING WINDS AND A FEW TORNADOES.

TSTMS ARE EXPECTED TO CONSOLIDATE INTO AN EWD/SEWD-MOVING MCS

OVERNIGHT WITH A RISK FOR DAMAGING WINDS...SEVERE HAIL AND PERHAPS A

TORNADO OR TWO SPREADING ACROSS THE EDWARDS PLATEAU AND HILL COUNTRY

TOWARD THE MIDDLE TX COAST.

[David Reimer]

AREA FORECAST DISCUSSION...UPDATED

NATIONAL WEATHER SERVICE FORT WORTH TX

1115 AM CST TUE JAN 24 2012

.UPDATE...

OVERALL THE CURRENT FORECAST FOR TODAY WAS ON TRACK BUT THE MOST

SIGNIFICANT CHANGE WAS TO INCREASE TEMPERATURES ACROSS THE REGION.

DESPITE LOW CLOUD COVER THIS MORNING...TEMPERATURES ARE WARMING

FASTER THAN WAS EXPECTED AND WILL LIKELY CONTINUE TO WARM INTO THE

AFTERNOON HOURS DESPITE INCREASING RAINFALL AND CONTINUED CLOUD

COVER. INCREASED TEMPERATURES ABOUT 4 TO 5 DEGREES ACROSS THE

BOARD.

SCATTERED SHOWERS CONTINUE TO MOVE NORTH THROUGH THE SOUTHERN

COUNTIES OF NORTH TEXAS THIS MORNING. ADDITIONAL RAIN ACTIVITY IS

INCREASING IN COVERAGE ACROSS THE HILL COUNTRY AND THE TEXAS

COAST...ALSO MOVING NORTH. THE WARM FRONT HAS MADE LITTLE PROGRESS

NORTH SO FAR THIS MORNING BUT THE WESTERN END OF THE FRONT HAS

STARTED TO MOVE NORTH IN RESPONSE TO CYCLOGENESIS OVER WEST TEXAS.

THE OVERALL THINKING OF HOW THE PRECIPITATION WILL TRANSPIRE TODAY

THROUGH TONIGHT IS LARGELY UNCHANGED. WE EXPECT THAT SHOWERS AND

ISOLATED THUNDERSTORMS WILL CONTINUE TO MOVE NORTH ACROSS OUR AREA

WITH THE GREATEST CHANCES FOR RAIN LATER THIS AFTERNOON AND

EVENING. DURING THE EVENING...THIS FIRST ROUND OF RAIN WILL HAVE

PUSHED NORTH TOWARDS THE RED RIVER AND THERE WILL LIKELY BE A DRY

PERIOD DURING THE EVENING AND OVERNIGHT HOURS. HOWEVER...A SQUALL

LINE IS EXPECTED TO DEVELOP WEST OF OUR REGION THIS EVENING AND

MARCH EAST OR SOUTHEAST OVERNIGHT AND WEDNESDAY MORNING. THE

PARTICULARS OF WHEN THIS MCS WILL ARRIVE AND EXACTLY WHAT AREA THE

MCS WILL COVER ARE STILL UNCLEAR BUT WILL MAINTAIN HIGH POPS IN THE

OVERNIGHT PERIOD.

REGARDING THE SEVERE WEATHER THREAT OVER NORTH TEXAS...THE

CONVECTION FOR THE REMAINDER OF THE DAY WILL REMAIN ELEVATED BUT

SMALL HAIL MAY BE POSSIBLE OUT OF STRONGER STORMS THIS EVENING.

THE WARM FRONT IS EXPECTED TO BE OVER OUR SOUTHERN COUNTIES THIS

EVENING AND OVERNIGHT AND THUS THIS AREA PRESENTS THE GREATEST

SEVERE WEATHER THREAT OVERNIGHT. AS THE MCS APPROACHES...STORMS

SOUTH OF THE FRONT WILL LIKELY BECOME SURFACE BASED AND WITH EAST

WINDS AT THE SURFACE...THE WINDS WILL BE FAVORABLE FOR ISOLATED

TORNADO DEVELOPMENT. THE LATEST CONVECTIVE DAY 1 OUTLOOK FROM SPC

LINES UP WELL WITH OUR THINKING THAT SEVERE AND POSSIBLY TORNADIC

STORMS MAY OCCUR SOUTH OF A LINE FROM COMANCHE TO WACO TO

CENTERVILLE. ELSEWHERE... HAIL AND DAMAGING WINDS WILL BE THE

MAIN THREATS DUE TO THE ELEVATED NATURE OF THE STORMS.

HOWEVER...THE ACTUAL LOCATION OF THE WARM FRONT WILL BE A KEY

FACTOR IN WHERE SURFACE BASED STORMS WILL OCCUR.

82/JLD

[Srain]

DAY 2 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1126 AM CST TUE JAN 24 2012

VALID 251200Z - 261200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF E TX INTO LA...

...SYNOPSIS...

A CLOSED UPPER LOW CENTERED OVER FAR W TX AT 12Z WEDNESDAY IS

EXPECTED TO MOVE SLOWLY...BUT STEADY EWD ACROSS TX. MODELS ARE IN

GENERAL AGREEMENT WITH THIS SCENARIO AND SUGGEST A TREND TOWARD THE

ENE LATE IN THE FORECAST PERIOD AS THIS SYSTEM BEGINS TO PHASE WITH

AN AMPLIFYING NRN STREAM TROUGH. AT THE SURFACE...THE PRIMARY

SYNOPTIC LOW SHOULD BE LOCATED IN DEEP S TX EARLY WEDNESDAY

MORNING...WITH THIS LOW TRACKING NEWD ACROSS THE COASTAL

PLAIN...REACHING THE ARKLATEX BY 12Z THURSDAY. A COLD FRONT

TRAILING SWD FROM THE SYNOPTIC LOW WILL ADVANCE EWD AND SHOULD

EXTEND SWD ALONG THE TX/LA BORDER INTO THE WRN GULF OF MEXICO BY THE

END OF THE FORECAST PERIOD. MEANWHILE...MODELS SUGGEST A SECOND

AREA OF LOW PRESSURE...POTENTIALLY ATTENDANT TO A LATE DAY 1/EARLY

DAY 2 MCS...WILL BE LOCATED FARTHER N OVER CENTRAL TX...AND SHOULD

CONCURRENTLY TRACK NEWD.

...E TX AND THE MIDDLE/UPPER TX COAST INTO LA...

A WARM SECTOR WILL SPREAD INLAND WEDNESDAY ACROSS E TX AND THE LOWER

MS VALLEY AS SELY-SLY LOW LEVEL FLOW ADVECTS A FEED OF WRN GULF

MOISTURE NWD AHEAD OF THE APPROACHING W TX UPPER LOW. ALTHOUGH

CLOUDINESS MAY TEND TO LIMIT SURFACE HEATING/GREATER INLAND

DESTABILIZATION ACROSS THE WARM SECTOR...FORECAST SOUNDINGS SUGGEST

LITTLE HEATING WILL BE NEEDED TO WEAKEN INHIBITION FOR TSTMS TO

DEVELOP ALONG THE RETREATING WARM FRONT...WITHIN THE WARM SECTOR AND

ALONG THE EWD ADVANCING COLD FRONT THIS PERIOD. STORMS AND

ASSOCIATED/ISOLATED SEVERE POTENTIAL WILL LIKELY BE ONGOING ACROSS

PARTS OF CENTRAL AND ERN TX AT THE START OF THE PERIOD. AS THE

SURFACE LOW REACHES E TX WEDNESDAY AFTERNOON...AN UPSWING IN TSTM

COVERAGE/INTENSITY IS EXPECTED ALONG THE TRAILING COLD FRONT WITH

THIS ACTIVITY ADVANCING EWD TO THE SABINE RIVER AND LA BY LATE DAY

2.

AS 40 TO 60 KT SSWLY MID LEVEL WINDS SPREAD EWD ATOP THE SURFACE

WARM SECTOR AND SLY/SELY LOW LEVEL FLOW...SHEAR WILL BE SUPPORTIVE

OF ORGANIZED/SUPERCELL STORMS. WHILE CONVECTION ON THE NRN FRINGE

OF THE REGION WILL LIKELY REMAIN SLIGHTLY ELEVATED...SURFACE-BASED

STORMS CAPABLE OF PRODUCING DAMAGING WINDS AND ISOLATED TORNADOES

ARE EXPECTED ACROSS E TX INTO LA.