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

[Srain]

Morning e-mail from Jeff:

 

Widespread severe weather outbreak likely today over the MS valley into east-central TX.
 
Usually warm air mass has spread very far northward for late January with 600am temperature of 59 degrees at Chicago. In fact the low so far this morning at BUSH IAH has been 72 which is about 10 degrees above our normal daytime high! With such a warm air mass over much of the nation east of the Rockies and a powerful storm system edging into the plains state, severe weather is likely. Locally southerly winds have remained gusty overnight and this continues to help break up or at least mitigate widespread sea fog conditions along the coast even though dewpoints are well above nearshore water temperatures. Have seen a better fetch of “chilled” wind over the extreme SE TX/SW LA coast where sea fog bank has maintained better definition over the past 24 hours. Will continue to deal with the sea fog threat for the next 12 hours or prior to the arrival of a fast moving cold front this evening.
 
Next item is the severe weather threat and chances for thunderstorms with the cold front this evening. Main dynamics and strongest lift will be focused NE of the region over AR where SPC moderate risk outline is in place. Best moisture is overhead now and will steadily shift eastward during the day well before the lift and slightly cooling arrive aloft. With afternoon surface temperatures likely filtering with 90 or better over NE MX in the slightly higher terrain and increasing SW winds in the mid level transporting this warm nose over the region…the dreaded cap looks to increase through the day. Highs in the upper 70’s will not be enough to break through the warm layer aloft especially given the deck of stratus. However some slight cooling of the mid levels may be possible as the trough axis approaches and combines with strong surface convergence with the cold front. While SPC slight risk takes in about the NE ½ of the region, feel the severe threat will be limited to the Lake Livingston area where capping is weakest and tail end of stronger dynamics aloft reside. Main threat in this area will be damaging winds to 60mph. For the rest of the area a broken band of showers and possibly a thunderstorm will be possible and this is supported by the TEXAS TECH meso model showing a thin line of showers/storms with the front. Think capping will hold strong over the southern and southwestern parts of the area keeping thunder out of the picture.
 
Front will quickly sweep offshore this evening with temperatures Wednesday morning 25 degrees cooler than today. Little weather is expected for the rest of the week into the weekend with lows in the 40’s and highs in the 60’s to near 70 under mostly sunny skies.
 
Severe Weather Outlook (Day 1):

[wxmx]

i think the mmw at the beginning off the month flipped a great pattern for us, though i freely admit to not knowing enough about the dynamics of it. maybe wxmx could chime in on it.

Yep, it helped break the pattern of higher than normal heights in both coasts. It displaced the vortex to SE Canada, but it was a rather tight PV, with a big gradient. It also made the pattern more volatile, very progressive. We need a looser PV and better west coast ridging. Things look so so  to bad for winter weather the next 10 days.

[Ed Lizard]

4 km ARW NAM depressing locally, but has potential to potentially destroy somewhere between Georgetown and Temple.  13Z HRRR also suggests some brief I-35 area fun.

[Ed Lizard]

 TEXAS COUNTIES INCLUDED ARE
    
     BOWIE                CAMP                CASS               
     COLLIN               DELTA               FANNIN             
     FRANKLIN             GRAYSON             GREGG              
     HARRISON             HOPKINS             HUNT               
     KAUFMAN              LAMAR               MARION             
     MORRIS               RAINS               RED RIVER          
     ROCKWALL             SMITH               TITUS              
     UPSHUR               VAN ZANDT           WOOD               
    
    
     ATTN...WFO...TSA...SHV...FWD...OUN...LZK...
 

[msp]

severe t-storm watch hoisted for much of cTX.  winds gusting to 45 here.

[DoctorMu]

This is a familiar scenario, although early.  83° record high in CLL, winds up to 40 mph, and a dry line/front with most of the energy and sever stuff well north.  I least my backyard had over 7 inches or rain in the past month.  don't anticipate much...

[CranberryWX]

Today you should get an introduction to the classic West Texas wind!  Enjoy ... and maybe wear a mask to keep the dust out.

No kidding! I feel like I have dust or grit everywhere, my ears, eyes, hair.... This can't be good for the lungs. You can smell the dust even inside.

On I-20 you could see clouds of dust hugging the ground like smoke. I can now relate to how it was like in the dust bowl days.

[DoctorMu]

Nice line forming N of Bryan

 

[DoctorMu]

We just had some pea size hail in CLL from a passing cell. A little nature surprise

http://imageshack.us/a/img585/8421/hailyeah.jpg

[Ed Lizard]

Depressing, only a tenth at local airports.  Stupid cap.

[Srain]

The overnight ensembles continue to advertise a moist Pacific zonal flow regime will become established as well as embedded short wave activity streaming in from the W. While rainfall across our region is not all that impressive, areas to our West and North that have been enduring a long term drought appear to benefit from such a pattern.

 

The latest updates from the GEFS/Euro Ensembles continue to suggest a phase/octant 8 MJO and that tends to favor a wet pattern as tropical forcing moved closer to the dateline.

 

Also of note are the increasing trends of a +WPO and a more neutral EPO as well as minor indications of a AO trend back toward a negative phase. Typically with tropical forcing we see a rise of a PNA Ridge across the Eastern/NE Pacific, but that remains to be seen. February tends to be a stormy month, climo wise and we will need to follow the trends to see if such a pattern will bring moisture across much of the areas that need rainfall and higher elevation snow.

 

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
1030 AM EST WED JAN 30 2013

VALID 12Z SAT FEB 02 2013 - 12Z WED FEB 06 2013

...GENERAL FLOW PATTERN...

A SHORT WAVELENGTH TROUGH/RIDGE PATTERN WILL GENERALLY HOLD IN THE
PAC NW/ROCKIES IN THE MEDIUM RANGE WHILE BROAD TROUGHING
ENCOMPASSES THE CENTRAL/EASTERN STATES. THE CANADIAN VORTEX SHOULD
STAY CENTERED JUST NORTH OF HUDSON BAY WITH INDICATIONS IT MAY
EVEN RETREAT FARTHER NORTH AND WEST BY MIDWEEK NEXT WEEK. THIS
PATTERN IS SUPPORTED BY DOWNSTREAM RIDGING OVER THE NORTH ATLANTIC
TO THE SE OF GREENLAND. THE NORTHWEST FLOW SHOULD KEEP MAINLY WEAK
CLIPPER SYSTEMS DOMINANT IN THE EAST WITH A MODEST SYSTEM PUSHING
INTO THE PAC NW BY TUE/D6.


...MODEL PREFERENCES...

THE MODELS SHOW GOOD AGREEMENT OVERALL WITH EXPECTED/MINOR RUN TO
RUN SHIFTS IN CONTINUITY... ESPECIALLY IN THE EAST. THE 00Z GFS
CORRELATES FAIRLY WELL WITH THE 00Z ECMWF AND ITS ENSEMBLE MEAN
THOUGH DOES TEND TO STRAY FARTHER FROM THE BEST ENSEMBLE
CLUSTERING OVER THE MIDWEST AND NORTHEAST EARLY NEXT WEEK.  USED A
COMBINATION OF THE 00Z/30 AND 12Z/29 ECMWF WITH SOME OF THE 00Z
ECMWF ENSEMBLE MEAN TO GET A GOOD CONSENSUS BASE OF THE AVAILABLE
GUIDANCE.

IN THE EASTERN PACIFIC... THE GUIDANCE HAS ALL COME AROUND TO
CUTTING OFF AN UPPER LOW WELL SW OF CALIFORNIA THIS WEEKEND NEAR
20N/135W. THE 06Z GFS CHANGED COURSE FROM ITS 00Z RUN AND BROUGHT
THE UPPER LOW INTO SOUTHERN CALIFORNIA TUE/D6... BUT THIS SCENARIO
HAS LOST FAVOR WITH THE BULK OF ENSEMBLE MEMBERS. QUESTIONS REMAIN
AS TO HOW MUCH MID-LEVEL ENERGY WORKS THROUGH CA/AZ EARLY NEXT
WEEK FROM THE NORTHERN PORTION OF THE TROUGH. THE 00Z ECMWF IS
LIKELY TOO STRONG WITH ITS VORT MAX AND EVEN CLOSES IT OFF OVER NW
MEXICO. BY WED/D7... THE MODELS RAPIDLY DIVERGE SOUTH OF THE GULF
OF ALASKA WITH POSSIBLE SFC WAVE DEVELOPMENT ALONG THE APPROACHING
COLD FRONT. FORECASTING/TIMING THESE ARE CHALLENGING TO SAY THE
LEAST SO TRENDED TOWARD THE 00Z ECMWF ENSEMBLE MEAN BY
TUE-WED/D6-7. THE 06Z GEFS MEAN WAS NOT AS DEFINED IN ITS PRESSURE
FIELD WITH COMPARATIVELY MORE ENSEMBLE SPREAD THAN THE ECMWF
ENSEMBLE HAD.


...SENSIBLE WEATHER IMPACTS...

A GENERALLY QUIET SEVERAL DAYS IS EXPECTED WITH THE NW FLOW
FAVORING LAKE EFFECT/ENHANCED PRECIPITATION AND ALSO OVER UPSLOPE
AREAS OF THE APPALACHIANS. BY NEXT WEEK MORE WIDESPREAD
PRECIPITATION IS LIKELY OVER THE PAC NW INTO NORTHERN CALIFORNIA.
TEMPERATURES SHOULD GENERALLY MODERATE FROM THE SHORT TERM BACK TO
NEAR NORMAL CONUS-WIDE.



FRACASSO
 

[DoctorMu]

Depressing, only a tenth at local airports.  Stupid cap.

0.25 in in the backyard. Kewl wind and hail though. Just enough for fun, but not enough for damage.

[Portastorm]

For those of us wanting to see a return (or just some) winter in the Southern Plains/Texas/northeastern Mexico ... the 0z and 6z GFS op runs are highly encouraging on or around Feb. 12-14.  Considering the GFS has suggested something like this for 5-6 straight runs, I think it shouldn't be dismissed outright just because we're talking "la-la land."

[Quixotic1]

For those of us wanting to see a return (or just some) winter in the Southern Plains/Texas/northeastern Mexico ... the 0z and 6z GFS op runs are highly encouraging on or around Feb. 12-14. Considering the GFS has suggested something like this for 5-6 straight runs, I think it shouldn't be dismissed outright just because we're talking "la-la land."

Saw that. Havent looked at any other models lately due to a busy schedule. 6z op is warmer but basically it snows in NOrth Texas for two days straight. if only.

[wxmx]

Looks like a colder pattern is brewing past the 10th...a good pattern for wintry precip in TX, with a positive tilted trough, an active STJ and strong W coast ridging (E coast ridging as a plus).

[wxmx]

BTW, this pattern change to colder is supported by teleconnections, with the AO dipping back below 0 and the MJO favoring an active STJ and colder pattern. It also fits nicely with the dates I sent to Portastorm in a PM about the return of winter.

[Portastorm]

BTW, this pattern change to colder is supported by teleconnections, with the AO dipping back below 0 and the MJO favoring an active STJ and colder pattern. It also fits nicely with the dates I sent to Portastorm in a PM about the return of winter.

 

Indeed it does sir, indeed it does! 

 

Here's to a large cold-core upper low bringing late-season wintry "fun" from NE Mexico up into Texas. That 8-1-2 MJO octant path is generally favorable to us for colder/wetter.

[bubba hotep]

BTW, this pattern change to colder is supported by teleconnections, with the AO dipping back below 0 and the MJO favoring an active STJ and colder pattern. It also fits nicely with the dates I sent to Portastorm in a PM about the return of winter.

 

Do share

[Srain]

A pleasant warm weekend is on tap for our Region as a NW aloft continues and a couple of weak boundaries or back door fronts move in and quickly wash out as a deep trough over the East continue to drop Clipper systems into the Great Lakes and the Mid Atlantic/NE.

Changes begin to appear late Sunday as a weak short wave traverses the Region with increasing clouds and a slight chance of showers late Monday into early Tuesday. Meanwhile to our West, the upper Ridge will break down and a series of short wave disturbance drop S into the Great Basin and a deepening trough begins to form along the California/Arizona/Mexico border. As the week progresses, clouds and returning moisture from an onshore flow and pressures falls to our West suggest warm and windy conditions with streamer showers may well return in earnest by Thursday into Friday.

Next weekend may offer a stormy period as a potent Winter Storm develops to our W and very slowly meanders E. There are still strong indications that a very noisy sub tropical jet and cool Canadian air will become an issue in the medium range and beyond. The long range GFS/Euro and their ensembles are hinting that a series of upper air disturbance will become entrenched across the Great Basin/Central/Southern Rockies and the Southern Plains lending to a chilly stormy pattern that may linger for several days. The MJO has entered phase/octant 8 and the latest Global ensemble data suggest the MJO will enter phase/octant 1 near the mid February time frame. The fly in the ointment develops across the Northern Hemisphere as a +PNA Pacific Ridge develops as well as a tanking AO and indications of a blocking W based -NAO pattern develops lending to a general troughy pattern over much of North America and a reloading of very chilly air across E Alaska/W Canada. We'll need to watch the mid February time frame for a return to a Winter like pattern which would fit well climo wise for our Region.

 

 

Euro Ensembles:

 

GEFS:

[wxmx]

Part 5 now available at:

http://www.americanwx.com/bb/index.php/topic/39149-texasnew-mexicolouisianamexico-obs-and-discussion-thread-part-5/