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

[patrick7032]

SPC SWODY1

 

I think EWX, as I think MAF covers SJT to a degree, but SJT would better sample upstream from DFW.  I'd like a balloon IMBY (HGX) but that would be close to LCH.  It amazes me how often we're capped when LCH isn't, as close as they are.

I agree with you about MAF covering SJT..and originally thought of EWX too as a site...but then thought as the ballon ascended it would come into approach patterns for AUS and SAT from a pilots perspective...and with SJT having only American Airlines as the commercial airline here...with only 3 flights a day...figured it would be less of an impact to aviation. Either spot would work...and agree with the Houston area needing a site too. Theres a few data void areas that need to be filled...and having launched ballons have thoughts on good spots...but that's another "soapbox" that I won't dive into...lol.

[Srain]

Morning e-mail from Jeff:

 

Windy, warm, and humid for the next 36-48 hours as the next storm system approaches the state.
 
Lower pressures over the central plains will result in gusty southerly winds today and Tuesday and severe weather across the plains mainly north of TX. This is a result of pieces of energy ejecting out of the mean upper level trough over the western US. SE TX will lie too far south and removed from the main thrust of the dynamics aloft to generate any significant deep convection. A few showers may try and develop under the increasing capping inversion, but suspect these will be isolated.
 
Large scale western US upper trough will begin its eastward movement by mid-week while a downstream blizzard develops over the central plains forcing a cold front into TX late Tuesday. This front will reach the region early Wednesday and cross off the coast by late in the afternoon. Still looks like the main dynamics are aimed north of SE TX and capping concerns look likely especially south of I-10. However latest guidance has been trending slightly wetter with the front and suspect a line of showers and thunderstorms will develop just NW of SE TX early Wednesday morning and cross the area during the day. Any severe weather threat appears to be located north of I-10 where the capping stands the best chance of being broken. SPC does bring the slight risk outline into a good portion of our northern counties, but this may be somewhat overdone given the time of day and potential warm mid-levels.
 
Cold front moves off the coast late Wednesday but main upper trough is slower and lags behind the front resulting in the potential for some elevated showers and thunderstorms Wednesday night into Thursday morning in the cold air. Shorter range models are just now starting to run to this time period and are giving some support to the ECMWF over the drier GFS.
 
Dry and cold again Thursday and Friday with well below normal temperatures for April. Lows fall back into the low to mid 40’s by Friday morning with highs on Thursday only in the mid to upper 60’s. Warming trend starts late Friday as winds swing back around to the ESE. 

[Srain]

Morning e-mail from Jeff:

 

Humid and breezy morning in progress will become and warm and windy afternoon as the next storm system approaches the state from the west.
 
An upper level trough over the western US is creeping into the plains with surface low pressure deepening over KS with blizzard conditions developing NE from CO into the central and northern plains. A secondary surface low pressure will be developing over NE NM and the TX panhandle today and will help be response for an outbreak of severe weather over N TX into OK this afternoon and evening. Surface cold front will dive southward into TX late today and into SE TX on Wednesday. Defined and established warm sector will remain capped off by warm air in the mid levels for today and into early Wednesday. While some models are attempting to erode the capping, I think they may be overdoing the cooling in the mid levels. Even so, strong frontal push could be enough to overcome the warm layer and force surface parcels through the cap. Shear and instability will be favorable for strong to severe storms should the cap break. Think the best chances for active weather will be north of I-10 where the capping is weakest and jet stream dynamics strongest and this is where SPC has outlined a slight risk of severe weather on Wednesday. South of I-10, capping may hold back storms to just a thin line of showers as suggested by the TX TECH model. Will review the severe threat again early Wednesday, but at this time it looks like most of the action will be north and east of our region. 
 
A secondary short wave rounding the base of the mean upper trough will move across the area Wednesday night. May see some additional development of showers and thunderstorms in the post frontal cold air mass late Wednesday night into Thursday morning.
 
With decent moisture profiles in place widespread rains of .5 to 1 inch will be possible with isolated totals up to 2 inches especially north of I-10 and east of I-45. Lower rainfall amounts will be found around the Matagorda Bay area southward. 
 
Another cold air mass will drop into the region behind the Wednesday cold front with lows falling back into the 40’s on Thursday and Friday mornings. Highs on Thursday may not reach 70 depending on when clouds clear. Slow warming trend starts Friday on into the weekend.

SPC Day 2 Severe Weather Outlook (Wednesday):

[Ed Lizard]

Someone at NWS HGX has obviously confused "pessimistic" with "optimistic".  I'm glass half full, myself.

 

 

 

WHILE THERE ARE STILL CONCERNS WITH WHETHER OR NOT THE CAP WILL/
CAN BE BROKEN...HAVE OPTED TO REMAIN ON THE PESSIMISTIC SIDE FOR
TODAY/TONIGHT. VERY STRONG DYNAMICS AT THE SFC (WITH THE SHARPLY
DEFINED COLD FRONT)...THE BROAD BUT VERY PRONOUNCED SPLITTING OF
THE UPPER JET AND THE TIMING OF SAID COLD FRONT SHOULD BE ENOUGH
TO BREAK THE CAP AS THESE SYSTEMS CONVERGE OVER SE TX THIS AFTN.
WARM MOIST UNSTABLE AIR ACROSS THE REGION ALONG WITH THE PROGGED
S/WV DO INDICATE AN ACTIVE AFTN/EVE FOR THE CWA.

 

 

[Srain]

Morning e-mail from Jeff:

 

Impressive late season cold front marching through TX this morning.

 

Current temperature at Waco is 45 while Austin is 74. Strong cold front is moving SE at 15-20mph and will be entering our northern counties by mid-morning. Temperatures will rapidly fall from the mid to upper 70’s into the upper 40’s and low 50’s with the frontal passage. This system is very dynamic and cold and this is resulting in rare April winter precipitation across portions of W and NC TX this morning with thunderstorms ongoing in the cold/near freezing air mass. Currently Abilene is 33 with a thunderstorm. This is a result of the warm moist Gulf air being pushed up and over the surface cold dome which is very cold for April. Thus far on the warm side of the front, capping has held strong and there appears to be few signs of it starting to weaken yet. Combined effect of strong surface lift with the sharp front, approaching cooler air in the mid-levels with the upper trough, and broad spreading apart of upper level winds (divergence aloft) all should help to weaken the capping today. However, with that said, still think it will be hard to get strong to severe storms south of I-10 where the cap is strongest with an isolated severe storm north of I-10 possible. Short term forecast models are not overly impressive with thunderstorms today as the main dynamics do not match up with the frontal timing….the front is running ahead of the main thrust of lift due to the slow movement of the upper trough and the fast movement of the dense cold air. Think most of the area will see a line of showers and maybe a thunderstorm move from NW to SE across the region from late morning through late afternoon.
 
Based on upstream trends, think the better chances for showers and thunderstorms may actually come this evening and overnight in the cold air behind the front as the upper trough axis moves across the area lifting the warm Gulf air mass over the surface cold dome. This is supported by the 4km WRF and seems reasonable.
 
Skies should clear on Thursday as the trough moves east of the area, but it will be cool to cold by April standards with highs in the low to mid 60’s. Could see some locations east of I-45 stay in the 50’s if cloud cover hangs around most of the day. Coldest morning will be Friday with lows in the lower 40’s under clear skies and calm winds.
 
Weekend forecast looks to be mainly dry and mild as SE winds begin to return moisture to the area. There is some interest in a strong short wave for Sunday, but meager moisture return should negate rainfall…but this feature will be something to keep an eye on over the next few days.    

[DoctorMu]

Capping (i.e., AggieDome) holding strong in CLL but hoping for overrun this afternoon.  Just planted a Monterrey Oak (Mexican White Oak) in the front after 2 red oaks in a row succumbed to summer drought season.  These puppies allegedly should be able to deal with our alkaline water and weather extremes.  Lawn and garden in central Texas is not for the faint of heart.

[Ed Lizard]

Capping (i.e., AggieDome) holding strong in CLL but hoping for overrun this afternoon.  Just planted a Monterrey Oak (Mexican White Oak) in the front after 2 red oaks in a row succumbed to summer drought season.  These puppies allegedly should be able to deal with our alkaline water and weather extremes.  Lawn and garden in central Texas is not for the faint of heart.

 

 

Not sure cap will break ahead of the front, but FWS/FTW had about 2000 J/Kg elevated CAPE, and CRP sounding, while solidly capped, had a fat CAPE region above that with nice speed and directional shear.  Hail behind the front seems possible.

 

 

Latest NAM seems to suggest some activity on or even a touch ahead of the front towards lunch time in SETX.  9Z SREFs are pessimistic on the HGX area reaching a tenth of an inch in three hours, so only cautiously optimistic.

[Ed Lizard]

I wonder if that little low on the cold front SW of SAT will be our friend today locally...

[DoctorMu]

Bring it.  We got nothing until that warm moist air was shoved upward at the front.  Some nice, winter-like overrun drizzle currently in CLL.  I don't think I've every seen anything like this in April in TX, but then it's part of the same system that brought a tornado and blizzard within an hour to Akron, CO.

 

 

We had a 21° drop in just a handful of min.  The winmap is particularly kewl today

 

http://hint.fm/wind/

[My Weather Today]

Prognostic Discussions Valid: Apr 16 - 20, 2013 (6-10 Day Outlook)
Valid: Apr 18 - 24, 2013 (8-14 Day Outlook)
Issued: Apr 10, 2013

 

 

 

PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD 300 PM EDT WED APRIL 10 2013  6-10 DAY OUTLOOK FOR APR 16 - 20 2013  TODAYS GFS AND ECMWF ENSEMBLE MEANS ARE IN GOOD AGREEMENT ON THE EXPECTED  LONGWAVE PATTERN, FEATURING A SUBTROPICAL RIDGE ACROSS THE SOUTHWEST ATLANTIC,  A BROAD TROUGH CENTERED OVER THE GREAT PLAINS, AND A CLOSED 500-HPA RIDGE  ACROSS THE BERING SEA. THE 0Z CANADIAN ENSEMBLE MEAN REMAINS THE MOST  PROGRESSIVE MODEL SOLUTION WITH THE LONGWAVE TROUGH AXIS ACROSS THE LOWER 48  AND WAS DISCOUNTED AS AN OUTLIER. THE HIGH-RESOLUTION 0Z ECMWF MODEL RUN  REPRESENTS THE OTHER EXTREME WITH LARGE POSITIVE 500-HPA HEIGHT ANOMALIES ALONG  THE EAST COAST.   A BROAD TROUGH WITH BELOW NORMAL 500-HPA HEIGHTS FAVOR BELOW NORMAL  TEMPERATURES ACROSS THE NORTHERN ROCKIES, GREAT PLAINS, AND MIDWEST. THE  HIGHEST ODDS FOR BELOW NORMAL TEMPERATURES ARE FORECAST FOR THE NORTHERN GREAT  PLAINS WHERE DAILY MAXIMUM TEMPERATURES ARE FORECAST TO AVERAGE 10 TO 20  DEGREES F BELOW NORMAL. EXPECTED ABOVE AVERAGE TEMPERATURES AHEAD OF A COLD  FRONT TILT THE ODDS TOWARDS ABOVE NORMAL TEMPERATURES ACROSS THE MID-ATLANTIC  AND SOUTHEAST. ABOVE NORMAL 500-HPA HEIGHTS FAVOR ABOVE NORMAL TEMPERATURES  ACROSS CALIFORNIA AND THE DESERT SOUTHWEST.  ON DAYS 6 AND 7, A COLD FRONT INTERACTING WITH ABUNDANT GULF MOISTURE IS  EXPECTED TO BRING ABOVE MEDIAN PRECIPITATION TO MOST OF THE EASTERN CONUS.  LATER IN THE PERIOD, A FRONTAL BOUNDARY, SEPARATING WELL BELOW NORMAL  TEMPERATURES ACROSS THE UPPER MIDWEST AND NEAR TO ABOVE NORMAL TEMPERATURES  ALONG THE GULF COAST, IS EXPECTED TO FOCUS ADDITIONAL RAINFALL ACROSS THE OHIO  AND TENNESSEE VALLEYS. UPSLOPE FLOW INCREASES CHANCES FOR ABOVE MEDIAN  PRECIPITATION ACROSS THE CENTRAL HIGH PLAINS AT THE BEGINNING OF THE PERIOD.  BELOW MEDIAN PRECIPITATION ACROSS THE LOWER 48 IS EXPECTED TO BE LIMITED TO THE  WESTERN CONUS WITH A RIDGE UPSTREAM ACROSS THE NORTHEAST PACIFIC.  ANOMALOUS NORTHERLY FLOW INCREASES CHANCES FOR BELOW NORMAL TEMPERATURES AND  BELOW MEDIAN PRECIPITATION ACROSS ALASKA.  TODAY'S OFFICIAL 500-HPA BLEND CONSISTS OF 10 PERCENT OF TODAY'S OPERATIONAL 6Z  GFS CENTERED ON DAY 8...30 PERCENT OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON  DAY 8...30 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...AND 30  PERCENT OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8.   MODEL OF THE DAY: 0Z GFS, 6Z GFS, AND 0Z ECMWF ENSEMBLE MEANS (TIED).   FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO  GOOD AGREEMENT AMONG THE GFS AND ECMWF ENSEMBLE MEANS.   8-14 DAY OUTLOOK FOR APR 18 - 24 2013   THE 0Z/6Z GFS AND 0Z ECMWF ENSEMBLE MEANS INDICATE A BROAD TROUGH COVERING MOST  OF THE CONUS BUT ABOVE NORMAL 500-HPA HEIGHTS ARE FORECAST ALONG BOTH COASTS.  THE 500-HPA HEIGHTS, PREDICTED BY THE 0Z ECMWF ENSEMBLE MEAN, ARE SLIGHTLY  LOWER ACROSS THE SOUTHERN GREAT PLAINS THAN THE 0Z/6Z GFS ENSEMBLE MEANS. SINCE  THE HIGH-RESOLUTION 0Z GFS MODEL RUN IS IN GOOD AGREEMENT WITH ITS ENSEMBLE  MEAN SOLUTION, MINOR WEIGHT WAS GIVEN TO THE HIGH-RESOLUTION 0Z GFS MODEL RUN  IN CREATING THE OFFICIAL 500-HPA BLEND. FOR THE SECOND CONSECUTIVE DAY, THE 0Z  CANADIAN ENSEMBLE MEAN INDICATES A HIGHLY AMPLIFIED TROUGH EXTENDING SOUTH TO  THE GULF OF MEXICO WHICH IS NOT SUPPORTED BY THE 0Z/6Z GFS OR 0Z ECMWF ENSEMBLE  MEANS. IN ADDITION, THE 0Z GFS ENSEMBLE MEMBERS INDICATE A POSITIVE NORTH  ATLANTIC OSCILLATION (NAO) INDEX DURING WEEK-2. THEREFORE, THE NAEFS  TEMPERATURE FORECAST OF HIGH PROBABILITIES FOR BELOW NORMAL TEMPERATURES ACROSS  THE SOUTHEASTERN CONUS IS CONSIDERED TO BE OVERDONE.    BELOW NORMAL TEMPERATURES ARE EXPECTED TO PERSIST ACROSS THE NORTHERN GREAT  PLAINS, UPPER MISSISSIPPI VALLEY, AND GREAT LAKES WHERE BELOW NORMAL 500-HPA  HEIGHTS ARE FORECAST. AN UPPER-LEVEL RIDGE WITH ABOVE NORMAL 500-HPA HEIGHTS  ENHANCES ODDS FOR ABOVE NORMAL TEMPERATURES ACROSS CALIFORNIA AND THE  SOUTHWESTERN CONUS. ELSEWHERE, LOWER FORECAST CONFIDENCE EXISTS IN THE  TEMPERATURE OUTLOOK ACROSS THE SOUTHERN AND EASTERN CONUS. FREQUENT TEMPERATURE  CHANGES DURING THE WEEK-2 PERIOD FAVOR NEAR NORMAL TEMPERATURES FOR MOST OF  THESE AREAS.   THE FORECAST POSITION OF THE UPPER-LEVEL TROUGH IS EXPECTED TO INCREASE CHANCES  FOR ABOVE MEDIAN PRECIPITATION FROM THE MISSISSIPPI VALLEY TO THE EAST COAST.  WEAK RIDGING ALONG THE WEST COAST ALONG WITH THE LONGWAVE TROUGH AXIS SHIFTING  AWAY FROM THE WESTERN CONUS ENHANCES ODDS FOR BELOW MEDIAN PRECIPITATION ACROSS  MOST OF THE WESTERN CONUS.  THE TEMPERATURE AND PRECIPITATION OUTLOOKS FOR ALASKA ARE SIMILAR TO YESTERDAY  WITH THE BLOCKING RIDGE OVER THE BERING SEA REMAINING EXTREMELY STRONG.  THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 10 PERCENT OF TODAY'S  OPERATIONAL 0Z GFS CENTERED ON DAY 11...30 PERCENT OF TODAY'S 0Z GFS ENSEMBLE  MEAN CENTERED ON DAY 11...30 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  ON DAY 11...AND 30 PERCENT OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY  11.  FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: AVERAGE, 3 OUT OF 5, DUE TO  GOOD AGREEMENT AMONG THE GFS AND ECMWF ENSEMBLE MEANS OFFSET BY POOR AGREEMENT  BETWEEN THE NAEFS TEMPERATURE TOOL AND OTHER TEMPERATURE TOOLS.  FORECASTER: BRAD PUGH 

 

http://www.cpc.ncep.noaa.gov/products/forecasts/

 

[patrick7032]

I like the sound of this...

   DAY 4-8 CONVECTIVE OUTLOOK     NWS STORM PREDICTION CENTER NORMAN OK   0325 AM CDT WED APR 10 2013      VALID 131200Z - 181200Z      ...DISCUSSION...   AFTER A BRIEF PERIOD OF NEGLIGIBLE SEVERE PROBABILITIES...LOW-END   SEVERE POTENTIAL MAY DEVELOP OVER PARTS OF THE CNTRL/ERN GULF COAST   STATES ON D5-6 IN ASSOCIATION WITH A LOW-AMPLITUDE SRN STREAM   SHORTWAVE IMPULSE ENCOUNTERING AN ADVANCING WARM FRONT. THE   ECMWF/CMC ARE CONSISTENTLY FASTER/WEAKER THAN THE GFS...RESULTING IN   MORE SUBDUED INLAND PENETRATION OF A GULF AIR MASS AND MODEST   KINEMATIC FIELDS.       MORE PROMINENT SEVERE POTENTIAL WILL PROBABLY BE REALIZED TOWARDS   THE MIDDLE OF NEXT WEEK AS MODERATELY HIGH CONFIDENCE EXISTS IN THE   DEVELOPMENT OF A WRN CONUS UPPER-LEVEL TROUGH EARLY IN THE WEEK.   THIS WOULD SETUP RETURN FLOW FROM THE WRN GULF INTO THE CNTRL   CONUS...S OF A RELATIVELY TIGHT BAROCLINIC ZONE FROM THE MIDWEST TO   THE CNTRL/SRN PLAINS. THE COLD FRONT PASSAGE ON D1-2 IS NOT EXPECTED   TO BE AS DETRIMENTAL TO DRYING ACROSS THE GULF BASIN AS THE MOST   RECENT FRONTAL PASSAGE HAD...WHICH POTENTIALLY WILL YIELD A MORE   STRONGLY UNSTABLE WARM SECTOR. HOWEVER...CONFIDENCE IS VERY LOW IN   THE EVOLUTION OF THE WRN CONUS TROUGH WITH IMMENSE SPREAD IN BOTH   AMPLITUDE AND TIMING...WHICH WILL CERTAINLY EFFECT DOWNSTREAM   CYCLOGENESIS AND FRONTAL POSITIONS. AS SUCH...CONSIDERING ANY   HIGHLIGHT FOR A SPECIFIC AREA/DAY WITH 30 PERCENT OR GREATER SEVERE   PROBABILITIES IS PREMATURE ATTM.      ..GRAMS.. 04/10/2013

[cvgram]

As this is also an obs thread, will throw in my having a nice little 15-minute hail event that ended around 2:55 AM. Loud enough where it woke me up and had me running to check the skylight in my apartment....which is located right above the desk with the computers. Ugh. Am going to throw on some clothes and check outside to see if I have any left to get pics of. Not smart in this complex, but maybe the hoodrats will still be asleep.

Oh, location is far southwest houston.

Suz

[Srain]

A nice surprise that an additional upper air disturbance along the main trough axis to our W is producing elevated storms and rainfall. It''s making for a noisy and chilly early Thursday morning across SE Texas/Louisiana and will make for a messy commute this morning. Funny how the cap held prior to the front and now we are getting those heavier and noisy storms in the cold air. That is what make weather so unpredictable at times and why we follow it with great interest.. Stay safe during that morning drive to work.

The guidance is still insisting that this frontal boundary will return N as a warm front over the weekend as yet another upper air disturbance crosses Texas late Saturday into Sunday bringing additional showers and storms. The models are also very instant that another strong push of Canadian air will head S late next week as a trough deepens across the W and chilly air returns once again for the weekend of the 20th.

[Srain]

Morning e-mail from Jeff:

 

Fairly active night across SE TX as the 850mb front and strong short wave combined to produce numerous elevated thunderstorms…many of which contained small hail and a plethora of lightning. 
 
Back edge of the activity is along a line from Huntsville to Katy to Palacios and moving E at 30-40mph. Radar and ground truth reports indicate a solid .5-1.5 inches along and SE of US 59 overnight with a few locations pushing 2.0-2.5 inches over the NW part of Galveston Bay and in eastern Harris County.

In addition to the rainfall, surface temperatures have fallen into the low 40’s for most location which is only a few degrees off the record for the day. Upper trough and clearing line will progress rapidly across the region this morning and afternoon allowing strong April sun to work on this cold low level air mass. Even with the cold start, we should be able to rebound into the upper 60’s by late this afternoon.
 
Cold again Friday morning under clear skies and light winds with lows in the lower to mid 40’s for most areas. Winds swing back to the SE late Friday and a warm front begins to take shape off the coast. Models remain fairly aggressive in bringing a strong short wave into the area on Sunday from the SW. While this seemed a bit of a reach yesterday the agreement in the models over the past 24 hours cannot be ignored and rain chances are now being required on Sunday. There remains some debate on how much moisture will work into the area, but there is some increasing concern that with a warm front lifting northward and strong lift from the short wave, convection will develop near the coast late Saturday and spread rapidly ENE across areas mainly south of I-10 early Sunday. If models continue to show good agreement on this feature, rain chances may need to be increased more on Sunday.
 
Increasingly warm and humid early next week under southerly flow and mostly zonal (west to east) flow aloft. Next potential cold front penciled in for about a week from today.  

 

[Ed Lizard]

I gave up on that disturbance coming around the trough too early and went to bed.  Even commented on it on local KHOU-TV 11 forum, when it became obvious front wouldn't break cap, but I expected to see signs earlier than I should have, I guess.

[DoctorMu]

Most of the "decapitation" was east of CLL - just had a sprinkle here and 0.25 in out of the overrun and disturbance...while precip dance tantalizingly to our east.   Huntsville had 0.52 in just this am.

[Ed Lizard]

Nice little show of semi-well develeoped alto-cu this morning, not quite 'turret' or castle like in appearance, but better developed than garden variety, with some virga beneath. 

Dewpoints generally below 60ºF (about 16º Canadian), SPC meso PWs well below an inch, with better moisture far offshore and local winds (as seen by car dealership flags along the interstate) generally from the East.

I suspect tonights disturbance won't encounter enough moisture to work with until it gets to Louisiana.  But, as an amateur hobbyist who can also be rose colored glasses optimistic, I can still be glass quarter optimistic we can get a few elevated storms and I can skip watering the lawn tomorrow.

[Ed Lizard]

Sure, at 60 hours the NAM is for entertainment purposes only, and the LFC is higher than I'd like.  But it does fire a lone cell up late Wednesday up Highway 6 near the Fighting Farmers, and it is due to have a perfect forecast someday.

[Srain]

Morning e-mail from Jeff:

 

Strong cold front will bring near record cold temperatures by the end of the week.
 
In a pattern that continues to repeat, another strong upper level storm system will cross the state on Thursday ushering in a strong cold front. Ahead of this feature a warm and muggy air mass is noted across much of eastern TX with dewpoints well into the 60’s and at some sites the lower 70’s. Warm layer of air aloft is keeping a cap on any convective chances with some slight potential especially on Wednesday of a showers or two moving inland off the western Gulf in the offshore flow. Onshore flow is also bringing in a large amount of haze/smoke from agriculture fires in Mexico. There will be little change to the pattern until Thursday when a strong cold front sweeps across the area.
 
Models have shown a general slowdown in the frontal timing with the boundary entering our W counties in the mid to late morning and moving off the coast toward the early evening. This paces the boundary across the region during maximum heating and during the greatest amounts of instability. As with the past front past week, the capping inversion held strong along the boundary allowing no development until the lift from the upper trough arrived during the overnight hours. Capping looks to be a problem with the upcoming front also, especially across areas south of I-10. Areas north of I-10 stand at least a decent shot of the cap being broken, and with good instability and strong shear, any storms that develop in this region will likely become severe. Hard to pin down the severe threat still over 48 hours out and will take a closer look tomorrow.
 
Post front air mass will be cold from mid April with lows both Friday and Saturday mornings falling into the upper 30’s and lower 40’s which is near record temperatures. Highs on Friday will only reach the mid to upper 60’s and only 70 on Saturday or roughly 10 degrees below daytime highs. The dry and cold air mass will feel much different than the current air mass in place.

 

[Ed Lizard]

GFS and NAM are very different, but agree Houston area will see a sharp gradient in rainfall Thursday, with Southern areas not getting much.

 

 

But NW Texas has cleared out nicely per vis satellite, and there may be a hint of a poorly defined triple point low near San Angelo.  Maybe a shade South of where the new SWODY1 Slight Risk is.  But it is worth watching as temps approach 80ºF an hour before solar noon...

[DoctorMu]

GFS and NAM are very different, but agree Houston area will see a sharp gradient in rainfall Thursday, with Southern areas not getting much.

 

 

But NW Texas has cleared out nicely per vis satellite, and there may be a hint of a poorly defined triple point low near San Angelo.  Maybe a shade South of where the new SWODY1 Slight Risk is.  But it is worth watching as temps approach 80ºF an hour before solar noon...

 

 

That's my concern that CLL through NW Harris will miss a soaking with the cap hanging on while Hearne to particularly Huntsville then east could seen an inch or more.  Here's to AggieDome busting!

 

 

 

btw, the Monterrey Oak (Mexican White) may turn out to be our best L&G investment ever.  It actually seems to like our alkaline water and is looking more vigorous after 8 days in the ground.

[Ed Lizard]

Seeing some cu where low clouds burned off, still think there is a suggestion of a triple point between humid, dry and cooler air, and new HRRR suggests something may develop near Tom Green county and head Northeast.

[Ed Lizard]

Quitting time, but I still think an isolated, but rambunctious, storm or two may pop soon in 'The Big Country'...

 

 

[Ed Lizard]

Quitting time, but I still think an isolated, but rambunctious, storm or two may pop soon in 'The Big Country'...

[Ed Lizard]

 

Quitting time, but I still think an isolated, but rambunctious, storm or two may pop soon in 'The Big Country'...

 

[Ed Lizard]

Stupid cold Winter.  Miserable, cold, but no winter precip fun.

 

And now I suspect 5 years w/o a severe t-storm IMBY...

 

Look at the satellite loops, Gulf is clear until deep fetch hits the cold shelf waters...

 

 

[My Weather Today]

I hope my neighbors down south get some relief from this ongoing epic drought they are currently experiencing...

 

 

 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
151 PM CDT THU APR 18 2013
 

 

...GFS/ECMWF STILL BRING A SFC FRONTAL BOUNDARY THROUGH AS AN UPPER
TROUGH PUSHES TO THE NORTH ON TUESDAY NIGHT INTO WEDNESDAY MORNING.
ENSEMBLE MEMBERS STILL SHOW SOME UNCERTAINTY AND THERE IS A BIT OF A
DISCREPANCY BETWEEN THE GFS/ECMWF BUT INHERITED FORECAST IS
BASICALLY RIGHT IN THE MIDDLE AND LOOKS TO BE THE BEST ESTIMATION AT
THIS TIME CALLING FOR A EARLY WEDNESDAY AM FRONTAL PASSAGE. AND
COMPARED TO FRONTS SO FAR THIS YEAR AN UNUSUAL FEATURE MAY ACCOMPANY
THIS FRONT...IN THE FORM OF LIQUID PRECIPITATION. AS THE LOWER
BOUNDARY LAYER JUICES UP...LIFTING TOTAL COLUMN PWATS TO 1.7 TO 1.9
INCHES THE FRONTAL BOUNDARY LIFTS AN AREA OF SHOWERS AND STORMS WITH
A SHORT LIVED AREA OF OVERRUNNING PRECIPITATION BEHIND THE FRONT.
WITH THE CONSISTENCY OF THIS SIGNAL OVER THE LAST FEW DAYS DID GO
AHEAD AND INCREASE TO A 30 PERCENT CHANCE OF SHRA/TSRA CENTERED
AROUND WEDNESDAY MORNING. 12Z GFS DID START TO BACK DOWN ON HOW
EFFICIENTLY THE FRONT MOVES THROUGH THOUGH...AND THE MOST DIFFLUENT
FLOW WAS CENTERED A BIT TO OUR EAST...FIGURED THOUGH THAT IF THE
FRONT WERE TO STALL IN THE AREA THAT WOULD STILL KEEP PRECIP IN
PLAY. IT SHOULD BE NOTED THOUGH THAT THE CMC...AN OUTLIER KEEPS THE
FRONT WELL TO THE NORTH OVER CENTRAL TEXAS SO DESPITE THE GFS/ECMWF
CONSISTENCY WE MAY YET END UP HIGH AND DRY. FORECAST ASSUMES A
FRONTAL PASSAGE WITH AT LEAST SOME DEGREE OF COOL ADVECTION LOWERING
MAX TEMPS INTO THE MID 70S TO LOW 80S THROUGH WEDNESDAY AND THURSDAY.
 

 

[Ed Lizard]

Mid week dank cool drizzliness after record cold end of the week.

 

Spring is rather dull this year.

[Srain]

Morning e-mail from Jeff:

 

Summer seems to be having a hard time taking hold this year, unlike the past several as another shot of unseasonably cold air comes down into the area tonight.

 

Cold front over NW TX with sub-freezing temperatures into the TX panhandle and mid 40’s over NW TX will move southward and into the region late this afternoon and off the coast toward Wednesday morning. Air mass ahead of this front is strongly capped by a layer of warm air in the mid-levels…that sounds familiar! Front should progress through the region with only a thin band of showers as capping holds strong. Surface boundary will stall over the northwest Gulf on Wednesday with warm southerly flow surging up and over the surface cold dome resulting in a period of overrunning. Weak short waves in the WSW flow aloft will help encourage the moist flow over the cold dome and help with marginal lift. Expect showers and possibly a few thunderstorms to continue behind the front especially toward the coast on Wednesday.

 

Conditions will be downright cold for late April standards with highs on Wednesday likely not getting much above 60 or some 20 degrees below normal. Gusty winds, clouds, and possible rainfall will make it feel like a winter day instead of late spring. Record low maximum temperatures may fall on Wednesday if the front passes through the area near of shortly before midnight as highs will likely be at that moment. A stronger short wave crosses the area early Thursday and this may end up being the greatest chance of rainfall this week.

 

Warm front will move northward on Friday returning the area to more normal temperatures and humidity. WSW to SW flow aloft remains through the period and this will allow weak ripples of energy to moves across the area every few days. Models are not in good agreement on when such disturbances may move across the region nor how strong they may be, thus will maintain at least 20-30% rain chances each day from Friday through the weekend, but these could go up or down depending on if a stronger disturbance approaches the area at some point.

 

 

 

 

 

[Ed Lizard]

GFS has been more pessimistic on rain last several events than Euro, and has generally been right.

 

Haven't seen 12Z GFS, but assuming it stays with sprinkles behind the front, that is probably what is going to happen.