February-Comfortable Days/Cool Nights To The Month

[Portastorm]

The outlook from this particular weather enthusiast is a bit depressing today. We just saw another frontal passage with minimal precipitation. We received about .08 at the Portastorm Weather Center. That's it.

I am equally disturbed by the change in the operational model runs over the last 36 hours. Five days ago, the last half of February looked like a winter bonanza for all of us. Now ... seasonal temps at best with minimal winter storm chances for anywhere from I-20 south in Texas. Per srainhoutx, recon is being performed in the Pacific with some WSR tasking and maybe that will change things. OR ... that already did change things and this is what we're going to get!

I'm very unclear as to why the models have transitioned to a less amplified, more progressive nature. The only thing I can think of is that this has been the pattern this winter with nothing locking in for very long. Cosgrove mentions this in his latest newsletter. Sadly, perhaps he is right. We shall see.

[srainhoutx]

The outlook from this particular weather enthusiast is a bit depressing today. We just saw another frontal passage with minimal precipitation. We received about .08 at the Portastorm Weather Center. That's it.

I am equally disturbed by the change in the operational model runs over the last 36 hours. Five days ago, the last half of February looked like a winter bonanza for all of us. Now ... seasonal temps at best with minimal winter storm chances for anywhere from I-20 south in Texas. Per srainhoutx, recon is being performed in the Pacific with some WSR tasking and maybe that will change things. OR ... that already did change things and this is what we're going to get!

I'm very unclear as to why the models have transitioned to a less amplified, more progressive nature. The only thing I can think of is that this has been the pattern this winter with nothing locking in for very long. Cosgrove mentions this in his latest newsletter. Sadly, perhaps he is right. We shall see.

I’m not so sure the computer models have a clue, Portastorm and frankly the HPC clearly doesn’t have much faith in any one solution right now other than the fact that a deep Central/Eastern trough appears likely during the upcoming time period heading into the late week/early next week time frame with Ridging across the NE Pacific. As we have seen there is so much run to run volatility even in the day 2-3 range to put too much faith in any medium/long range pattern potential at this point. What I’ve seen via the trends the last 48 hours has been the GFS and ensembles flip back to a less progressive pattern to that of what the Euro had somewhat hinted with energy trending further W into the Intermountain West. Is it the know bias of the European Centre Guidance that appears from time to time or a trend? That remains to be seen. The implications of any short wave dropping further to our W will need to be monitored and that is the reason for WSR (Winter Storm RECON) over the Pacific. The implications of a subtle change in any 500mb short wave phasing will have a major impact on the sensible weather down stream. That said is does appear there will be colder Canadian air dropping S later this week. As we have stated, this is not an Arctic Outbreak pattern that would bring colder temps greater than that we have seen so far the season, but it will bring back a taste of chilly temps. What will need to be monitored are the various upper air disturbance dropping S along the W flank of the deep trough. The RECON missions are scheduled for Monday night and Tuesday night, so we’ll see if the volatility seen in the guidance settles down over the next several days.

MODEL DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
153 PM EST SUN FEB 10 2013

VALID FEB 10/1200 UTC THRU FEB 14/0000 UTC

...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...

==================================================
FINAL 12Z MODEL EVALUATION INCLUDING THE ECMWF

...SYSTEM SWINGING THROUGH THE SOUTHERN TIER...

PREFERENCE: 06Z GFS
CONFIDENCE: AVERAGE

IN THE WAKE OF THE MIDWEST STORM...A LARGE SCALE TROUGH WILL
REMAIN IN PLACE WITH ENERGY CONCENTRATED BACK TOWARD THE SOUTHWEST
STATES. THE BASE OF THE TROUGH WILL SWING EASTWARD...INDUCING A
SURFACE LOW THAT THE GLOBAL MODELS TRACK FROM THE WESTERN GULF
COAST TO THE CAROLINAS. THE NAM AND RELATED SREF OUTPUT NOW MARK
THE SLOW EDGE OF THE GUIDANCE ALOFT...BUT 06Z AND 12Z GUIDANCE
CERTAINLY HAS TRENDED SLOWER. THIS INCLUDES THE UKMET WHICH
SUPPORTS OUR CHOICE OF THE 06Z GFS AS A MIDDLE GROUND. THE ECMWF
SHOWED THE GREATEST RUN TO RUN CHANGE...AS IT HAD BEEN MARKING THE
FAST END OF THE SPECTRUM AND THE 12Z RUN NOW JOINS THE NAM/SREF AT
THE SLOW END.

IT IS THE SURFACE WHERE THE NAM IS A STRONG OUTLIER...IN PRODUCING
A LOW TRACK THAT STAYS WEST OF THE APPALACHIANS AND MUCH FARTHER
INLAND THAN THE GLOBAL MODELS. EVEN THE CANADIAN AND RECENT GFS
RUNS...WHICH SUPPORT THE NAM IN OTHER RESPECTS...KEEP LOW PRESSURE
CONFINED TO THE PRE-EXISTING FRONTAL ZONE THAT WILL BE IN PLACE
ACROSS THE SOUTHERN/SOUTHEASTERN STATES. THE GFS IS THOUGHT TO BE
DEEPENING THE SURFACE LOW SOMEWHAT PREMATURELY...WITH DEEPENING
MORE LIKELY TO WAIT UNTIL THE SYSTEM REACHES THE WESTERN ATLANTIC
ON DAY 4. BUT THE 06Z AND 12Z GFS BETTER REPRESENT THE OVERALL
TREND WITH RESPECT TO TRACK. OVER THE PAST FEW RUNS...THE UKMET
SURFACE LOW TRACK HAS TRENDED CLOSER TO THE GFS AND GEFS
MEAN...AND NOW THE 12Z ECMWF SHARES THIS TREND ALTHOUGH
SIGNIFICANT DIFFERENCES STILL EXIST BEYOND DAY 3. IT IS CURRENTLY
DIFFICULT TO FIND ANY OPERATIONAL MODELS THAT CLOSELY FIT OUR
CONCEPTUAL MODEL...BUT IN COORDINATION WITH THE HPC MEDIUM RANGE
PRESSURE DESK...WE FAVOR THE 06Z GFS SURFACE LOW TRACK WITH JUST A
SLIGHT ADJUSTMENT TOWARD THE SOUTH/EAST AND WITH DELAYED
STRENGTHENING UNTIL REACHING THE WESTERN ATLANTIC.



WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1230 PM EST SUN 10 FEBRUARY 2013
SUBJECT: WINTER STORM PLAN OF THE DAY (WSPOD)
VALID 11/1100Z TO 12/1100Z FEBRUARY 2013
WSPOD NUMBER.....12-072

I. ATLANTIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.

II. PACIFIC REQUIREMENTS
1. FLIGHT ONE --NOAA 49--
A. P10/ DROP 6 (45.0N 159.0W)/ 12/0000Z
B NOAA9 08WSC TRACK10
C. 11/1900Z
D. 13 DROPS ON TRACK AS PUBLISHED
E. 41,000 TO 45,000 FT/ 12/0600Z

2. SUCCEEDING DAY OUTLOOK: POSSIBLE
A. P23/ DROP 8 (47.0N 175.0W)/ 13/0000Z

[weatherguy425]

As Srain mentioned, 12z Euro OP has a deeper trough which only slowly enters the state on Tuesday, before ejecting ENE. This run would mean fun for my local areas. Would Wxman57 mind posting a ECMWF snowfall accumulation image, bu chance?

[SusieinLP]

About .12 here. Meh. But better than nothing at all...hope we get more this week. I see the KHOU weather forecast has 49 as high on Friday. NOAA shows 60s.

[Cromagnum]

The climate here in Houston really has seemed to change. I remember 10 years ago we used to get strong thunderstorms pretty frequently, especially the popcorn kind from afternoon heating in the summer. Now it seems like everytime there is the possibility of thunderstorm activity, there is a cap in place and nothing happens. Our last two winters have been non-existent as well. I think there may have been less than 5 days both years where we actually got below 32 degrees. I'll be glad to move away as I really rather despise both the weather and the traffic here in this city (and I've lived either in Houston or College Station for all 31 years I've been around).

[mckinne63]

What a bust here in Stafford. Just gloomy, little to no rain. At least the temps cooled a bit.

[srainhoutx]

LOL...too bad we can't trust the models beyond the 2-3 time frame. The 00Z GFS now is suggesting light snow late next Friday into early Saturday for parts of Oklahoma/N Central/E Central and the Northern areas of SE TX on E into Louisiana....

[C2G]

It puts a smile on my face to hear the models have backed off any extremely cold temperatures. It warms my heart to know Spring is right around the corner, followed by long Summer days.
You winter weather lovers live at the wrong latitude.

[C2G]

Nice thunderstorm here on the island. Looks to be a very rainy day. Just hope it's not too hard on the way home.

.

[cristina99]

well, there's always next year. At least we'll get some cooler temps late this week.
I guess after living here all my life and enduring the 100+ degree early summers and sweating just about all the time, high electric bills, and such, I like the cold. Surely we all know Texas weather can change in 5 minutes. I just don't like the hot weather. You can't do anything and feel comfortable.

[Portastorm]

LOL...too bad we can't trust the models beyond the 2-3 time frame. The 00Z GFS now is suggesting light snow late next Friday into early Saturday for parts of Oklahoma/N Central/E Central and the Northern areas of SE TX on E into Louisiana....

It appears the models are struggling mightily right now. Dramatic differences in this morning's 8-10 day forecast from both the Euro and GFS. They even didn't grasp the extent of the rainfall (let alone severe storms in south Texas) overnight. Guess I need to go back to the old mental standby of "any model solution past 4 days cannot be believed."

[srainhoutx]

Morning e-mail from Jeff:

Periods of showers and thunderstorms will be likely over the next 24-36 hours.

Weak frontal boundary which passed across the region yesterday has stalled just offshore overnight. A shallow dome of cool air is in place across the region with light N winds. Above the surface strong SW flow is pulling moisture over the top of this surface cold dome resulting in modest lift. Sub-tropical jet stream is anchored across the region and within this flow small disturbances are rippling through the flow resulting in enhanced lift. One such disturbance is currently crossing the area leading to decent coverage of showers and thunderstorms. Both Corpus and Lake Charles soundings show decent mid level instability this morning suggestive of elevate thunderstorms and this is being confirmed on the lightening data maps showing increasing lightening strikes over the region. A few storms could reach strong levels this morning with small hail and gusty winds.

Current shortwave aloft (disturbance) will move east of the region by late morning and a gradual downward trend in rainfall is expected this afternoon. It is interesting to note that some of the short range guidance does redevelop activity this afternoon across the area. A look at water vapor images upstream over Mexico does not reveal any shortwave that I can see in the upper level flow (not saying it is not there). Such patterns tend to produce rounds of rainfall about every 6-12 hours.

Other item which continues to be a problem along the coast is sea fog. As the weak boundary lifts slowly northward today, dewpoints will surge into the mid and upper 60’s over the coastal waters. As this warm air flows across the cool waters it will chill to saturation allowing dense sea fog to form. Think mainly the coastal locations will have the biggest issues with sea fog, but it could spread as far inland as Liberty to Pearland to Bay City this evening depending on how quickly the coastal front backs northward. Visibilities over the coastal waters and bays will average between .50 of and mile and 0.

Tonight into Tuesday much better rain chances are likely as the main upper level trough over the 4 corners area ejects eastward into the central plains. Strong lift will come to bear across the region late tonight through Tuesday morning with widespread showers and thunderstorms likely. A few of these storms could be on the strong side. Rain should end by midday Tuesday as the system progresses to our east and a colder/drier air mass sweeps into the region from the NW.

Rainfall amounts today-Tuesday will average .5 to 1.0 inches across the region with isolated totals up to 2.0 inches especially east of I-45.

Rest of the forecast from Tuesday evening onward looks cool and dry with surface high pressure in control (lows in the 40’s and highs in the 60’s). Stronger cold front looks to arrive late Friday and usher in a colder air mass for the weekend with temperatures possibly near freezing across some of our northern counties Saturday morning. GFS model is trying to generate some post frontal light precipitation, but this is not supported by other guidance and for now will leave a dry forecast for Friday night into Saturday.

[srainhoutx]

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
754 AM CST MON FEB 11 2013

TXZ200-213-111445-
LIBERTY TX-HARRIS TX-
754 AM CST MON FEB 11 2013

...SPECIAL WEATHER STATEMENT...

AT 748 AM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
A STRONG THUNDERSTORM NEAR CROSBY...OR 7 MILES SOUTHEAST OF
KINGWOOD...MOVING NORTHEAST AT 40 MPH.

HAIL UP TO THE SIZE OF PEAS WILL BE POSSIBLE WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
LIBERTY...DAYTON...CROSBY...AMES...HARDIN...KENEFICK AND DAYTON
LAKES.

[srainhoutx]

Impressive QPF bomb via the 12Z 4km NAM for areas near Amarillo on E along the I-40 Corridor tomorrow...

[srainhoutx]

Interesting to see the 12Z GFS continue to suggest some lift as a Clipper type system moves across Eastern Oklahoma/N Central/Central/SE/E Texas on E into Arkansas/Louisiana Friday night into Saturday. WSR (Winter Strom RECON) will fly the N Pacific SW of the Aleutian Islands tonight as scheduled and possibly again tomorrow night as well. The Updated HPC Medium Range Discussion explains well why the operational and ensembles are struggling with the evolving pattern. Hopefully that additional data will settle down the volatility seen in the medium range over the next few days.

WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1110 AM EST MON 11 FEBRUARY 2013
SUBJECT: WINTER STORM PLAN OF THE DAY (WSPOD)
VALID 12/1100Z TO 13/1100Z FEBRUARY 2013
WSPOD NUMBER.....12-073

I. ATLANTIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.

II. PACIFIC REQUIREMENTS
1. FLIGHT ONE --NOAA 49--
A. P23/ DROP 8 (47.0N 175.0W)/ 13/0000Z
B NOAA9 09WSC TRACK23
C. 12/1900Z
D. 18 DROPS ON TRACK AS PUBLISHED
E. 41,000 TO 45,000 FT/ 13/0600Z

2. SUCCEEDING DAY OUTLOOK: POSSIBLE
A. P9/ DROP 7 / 14/0000Z
3. REMARKS: TRACK P10 WILL BE FLOWN TODAY AS
DETAILED ON WSPOD 12-072.


EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
1101 AM EST MON FEB 11 2013

VALID 12Z THU FEB 14 2013 - 12Z MON FEB 18 2013

MODELS SHOW RELATIVELY GOOD LARGE-SCALE EVOLUTION DAYS
3-7/THU-MON...WITH A HIGH AMPLITUDE TROUGH FORMING NEAR THE
MISSISSIPPI RIVER...WHILE PROGRESSIVE FLOW DEVELOPS ALONG THE WEST
COAST. HOWEVER...MODEL DETAILS INCLUDING THE ANTICIPATED
TIMING/STRENGTH OF INDIVIDUAL SHORTWAVE TROUGHS ARE MORE UNCLEAR
THAN USUAL DUE TO THE LARGE NUMBER OF TROUGHS/RIDGES AND APPARENT
SENSITIVITY TO THE FLOW CROSSING JAPAN THAT RESEMBLES A ROSSBY
WAVE PACKET...BOTH OF WHICH CONTAIN ENOUGH ERROR THAT IS DIFFICULT
FOR EVEN THE HIGHEST-RESOLVING ENSEMBLES TO ADDRESS...AND ARE
CONFIRMED BY THE HIGHER THAN USUAL SOLUTION SPREAD THROUGH THE
ENTIRE PERIOD. THEREFORE...CONFIDENCE IN THE DAY-TO-DAY SENSIBLE
WEATHER IS LOWER THAN AVERAGE.

BEGINNING WITH DAY 3/THU...THE UPPER TROUGH SHOULD BEGIN TO TAKE
SHAPE OVER THE PLAINS/MIDWEST IN RESPONSE TO THE WAVE PACKET OVER
JAPAN REACHING NORTH AMERICA...WITH THE 00Z GFS STRONGER THAN THE
00Z ECMWF WITH AN EMBEDDED SHORTWAVE TROUGH AFFECTING THE GREAT
LAKES...AND CLOSER/STRONGER THAN THE 00Z ECMWF WITH A SURFACE LOW
OFF THE NORTHEAST COAST. IN BOTH CASES...THE GLOBAL ENSEMBLE
MEMBERS AND THEIR RESPECTIVE MEANS SUPPORT INTERMEDIATE SOLUTIONS.

BY DAY 5/SAT...HEIGHTS SHOULD LOWER ALONG THE WEST COAST DUE TO
PASSAGE OF A SHORTWAVE TROUGH...WHILE A NEW AREA OF LOW PRESSURE
BEGINS TO DEVELOP ALONG THE NORTHEAST/MID-ATLANTIC COAST. THE
SOLUTION SPREAD BECOME HIGH BY THIS PERIOD...WITH THE 06Z GFS
REPRESENTATIVE OF SOME OF THE MORE EXTREME BUT NOT OUTLYING
ENSEMBLE MEMBERS WITH ITS FASTER SPEED ALONG THE WEST COAST AND
MORE AMPLIFIED/SLOWER PROGRESSION OF THE EASTERN TROUGH.

BY DAY 6/SUN...FOLLOWING THE INTERMEDIATE SCENARIO THAT MOST
CLOSELY RESEMBLES THE 00Z ECMWF ENSEMBLE MEAN...THE WEST COAST
TROUGH IS EXPECTED TO DIG ACROSS THE INTERMOUNTAIN WEST/ROCKIES
BEFORE REACHING THE PLAINS ON DAY 7/MON. THE 00-06Z GEFS MEAN
SHOWS EXCELLENT AGREEMENT WITH THIS APPROACH...WHILE THE 00Z
GFS/ECMWF AGREE WITH THE PHASE BUT SUGGEST VERY DIFFERENT PMSL
FIELDS. ALONG THE EAST COAST...THE 00Z GFS/ECMWF SHOW ACCEPTABLE
AGREEMENT WITH THE ECMWF ENSEMBLE MEAN'S LOW TRACK...BUT ARE
SLIGHTLY MORE OFFSHORE AND FASTER. HAVE EXCLUDED THE 06Z GFS
SCENARIO FOR THE MOMENT WITH ITS MORE EXTREME INLAND AND DEEP LOW
TRACK THAT HAS SUPPORT FROM LESS THAN 10 PERCENT OF THE GLOBAL
ENSEMBLE MEMBERS.

JAMES

[srainhoutx]

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE AMARILLO TX
233 PM CST MON FEB 11 2013

TXZ005-008>010-012>015-017>020-120500-
/O.UPG.KAMA.WS.A.0001.130212T0600Z-130213T0600Z/
/O.NEW.KAMA.WS.W.0001.130212T0900Z-130213T0300Z/
LIPSCOMB-HUTCHINSON-ROBERTS-HEMPHILL-POTTER-CARSON-GRAY-WHEELER-
RANDALL-ARMSTRONG-DONLEY-COLLINGSWORTH-
INCLUDING THE CITIES OF...BOOKER...HIGGINS...FOLLETT...BORGER...
MIAMI...CANADIAN...AMARILLO...PANHANDLE...WHITE DEER...PAMPA...
SHAMROCK...WHEELER...CANYON...CLAUDE...CLARENDON...WELLINGTON
233 PM CST MON FEB 11 2013

...WINTER STORM WARNING IN EFFECT FROM 3 AM TO 9 PM CST TUESDAY...

THE NATIONAL WEATHER SERVICE IN AMARILLO HAS ISSUED A WINTER
STORM WARNING FOR SNOW...WHICH IS IN EFFECT FROM 3 AM TO 9 PM CST
TUESDAY. THE WINTER STORM WATCH IS NO LONGER IN EFFECT.

* EVENT...SNOWFALL ACCUMULATIONS BETWEEN 6 AND 9 INCHES WITH LOCALLY
HIGHER AMOUNTS. THE HEAVIEST SNOWFALL ACCUMULATIONS WILL BE IN
LOCATIONS GENERALLY NORTH OF INTERSTATE 40 AND EAST OF A CANADIAN
TO PAMPA TO CLAUDE LINE.

* TIMING...SNOW WILL BEGIN AFTER 3 AM TUESDAY...INCREASE IN INTENSITY
TUESDAY MORNING THROUGH TUESDAY AFTERNOON...AND END BY TUESDAY
EVENING.

* IMPACTS...ROADS...BRIDGES...AND OVERPASSES IN THE WARNING AREA
WILL BECOME SLICK AND HAZARDOUS MAKING TRAVEL VERY DIFFICULT.

[srainhoutx]

A quick update for the late week time frame. The trends today via the 12Z suite of operational and ensemble guidance suggest that some low end precip chance may be increasing Friday afternoon into the over night hours extending into early Saturday as a 'clipper like' system drops SSE across Oklahoma and Texas before shift E. The European suite of OP/Ensemble mean have trended a tad 'wetter' and a touch further W with an upper air disturbance riding along the NW flow aloft along the W flank of a deepening East Coast trough. This precip is post frontal in nature and should be rather light. The 1000/500 mb thickness suggest a flurry or ice pellet or two may not be out of the question for Oklahoma/N Central/ portions of Central and the Northern areas of SE TX on E into Arkansas and Louisiana as much colder air drops S into the Southern Plains and a 1040mb Canadian High pressure builds in. As mentioned earlier, RECON will fly tonight and tomorrow night S and W of the Gulf of Alaska to sample the upper air pattern near 45,000 ft. That additional data should help to clear up the uncertainty that has been seen via the guidance and offer a sensible forecast solution for our Region and further E.

MODEL DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
149 PM EST MON FEB 11 2013

VALID FEB 11/1200 UTC THRU FEB 15/0000 UTC

...SHORTWAVE AMPLIFYING OVER THE GREAT BASIN THURSDAY...

PREFERENCE: BLEND OF 12Z GFS/ECMWF
CONFIDENCE: AVERAGE

ON THE HEELS OF THE NORTHERN ROCKIES/PLAINS SYSTEM...UPPER
TROUGHING WILL BEGIN TO AMPLIFY OVER THE INTERMOUNTAIN WEST AS
ADDITIONAL ENERGY DROPS DOWN FROM THE NORTHERN PACIFIC. THE 12Z
NAM IMPROVED UPON THE 06Z NAM IN SHOWING BETTER DEFINITION OF THIS
FEATURE. THE NAM IS SIMILAR TO THE 12Z GFS AND ECMWF IN PLACING A
WEST TO EAST ORIENTED TROUGH/VORTICITY MAXIMUM NEAR THE FOUR
CORNERS BY 15/00Z. IT IS WORTH NOTING THAT THE 12Z NAM STAYED
CLOSE TO CONSENSUS OVER THE PACIFIC...AND THIS MAY INCREASE
CONFIDENCE WITH ITS HANDLING OF THE WESTERN U.S. ON DAY 3. ON THE
OTHER HAND...THE NAM APPEARS TO ENHANCE THE MID LEVEL GRADIENT
FLOW OVER THE NORTHERN ROCKIES ON DAY 3 RELATIVE TO THE GFS AND
ECMWF...SUCH THAT THE NAM IS NOT INCLUDED IN THE PREFERENCE. THE
UKMET WAS FAST WITH THIS FEATURE...AND THE CANADIAN DIFFERED BY
REROUTING NORTHERN STREAM ENERGY TOWARD THE INTERMOUNTAIN WEST
RATHER THAN THE NORTHERN PLAINS. THIS IS LIKELY THE REASON FOR THE
CANADIAN BEING MUCH SLOWER THAN CONSENSUS WITH THE SYSTEM
DISCUSSED ABOVE. GIVEN THAT THIS SOLUTION IS CURRENTLY ON ITS
OWN...WE CONTINUE TO RECOMMEND THE CONSENSUS THAT IS BEST
REPRESENTED BY THE GFS AND ECMWF.

02112013 18Z gfs_namer_111_1000_500_thick.gif

02112013 18Z GFS gfs_namer_114_1000_500_thick.gif

[srainhoutx]

A nice snow event unfolding for Amarillo, Dumas, Borger, Canadian on E across the I-40 Corridor with many reports of thunder snow and 2 inch per hour rates and an impressive deformation band developing.

The over night RECON over the N Pacific did make it into the 00Z data ingest (12 high altitude, 4-5 lower altitude drops) and after a some what stormy day things should settle down Wednesday into Thursday before a stronger push of Canadian air moves across the Region overnight Thursday. Friday should be breezy and much cooler. The guidance is still advertising a clipper like system dropping SSE along the W flank of the developing trough to our E bringing some lift and light precip (mostly light rain), some of which may be in the frozen form Friday night. Dallas/Ft Worth, Shreveport and even Houston/Galveston NWS have made mention of this, but are not expecting anything significant as the lower levels appear too warm for much to reach the ground. A stray flurry or ice pellet or two may be possible before the system moves E giving us a chilly Saturday.

[srainhoutx]

MESOSCALE DISCUSSION 0155
NWS STORM PREDICTION CENTER NORMAN OK
0758 AM CST TUE FEB 12 2013

AREAS AFFECTED...TX PANHANDLE TO WESTERN/NORTH-CENTRAL OK

CONCERNING...HEAVY SNOW

VALID 121358Z - 121800Z

SUMMARY...MODERATE/HEAVY SNOW WILL CONTINUE TO DEVELOP
EAST-NORTHEASTWARD FROM THE TX PANHANDLE INTO WESTERN/NORTH-CENTRAL
OK THROUGH 18Z. SNOWFALL RATES SHOULD CONTINUE TO REACH 1 IN/HR
THROUGH EARLY AFTERNOON...WITH LOCALLY HIGHER RATES POSSIBLE FOR
RELATIVELY SHORT DURATIONS.

DISCUSSION...IN ASSOCIATION WITH AN EAST-NORTHEAST ADVANCING UPPER
TROUGH OVER NM/APPROACHING FAR WEST TX EARLY THIS MORNING...DEEP
LAYER ASCENT VIA UPPER JET EXIT REGION/WARM ADVECTION CONTINUES TO
CONTRIBUTE TO AN EAST-NORTHEASTWARD DEVELOPMENT OF PRECIPITATION
ACROSS FAR NORTH TX/TX PANHANDLE INTO WESTERN/SOUTHERN OK. AS OF
13Z...ZERO/SUB-ZERO SURFACE WET BULB TEMPERATURES ARE EVIDENT ACROSS
THE MAJORITY OF THE TX PANHANDLE AND INTO NORTHWEST OK /AREAS NORTH
OF I-40/. THESE COLDER TEMPERATURES CONTINUE TO ROUGHLY COINCIDE
WITH AREAS THAT ARE ALONG AND NORTH-NORTHWEST OF A WEAK SURFACE
INVERTED TROUGH/ZONE OF LOW-LEVEL CONFLUENCE.

ALTHOUGH THE 12Z OBSERVED SOUNDING FROM NORMAN WAS INDICATIVE OF AN
ABOVE-FREEZING WET BULB PROFILE BELOW 850 MB...THE ONSET OF STRONGER
FORCING FOR ASCENT/HIGHER PRECIPITATION RATES AND LOW-LEVEL COLD
ADVECTION SHOULD CONTINUE TO LEAD TO A GENERAL WEST TO EAST
TRANSITION OF RAIN TO SNOW INTO WEST-CENTRAL/NORTH-CENTRAL OK
THROUGH MIDDAY. THIS ASIDE...SOME SLEET WILL BE POSSIBLE WITH
PRECIPITATION ONSET AND/OR EXISTING CONVECTIVE ELEMENTS ACROSS
SOUTH-CENTRAL OK.

DEEP FORCING/SATURATION ASIDE...MID-LEVEL FRONTOGENESIS /800-600
MB/...ALONG WITH WEAK UPRIGHT INSTABILITY AND/OR SLANTWISE
INSTABILITY...WILL LIKELY ENHANCE SNOWFALL WITH RATES OF 1+ IN/HR
POSSIBLE INTO EARLY AFTERNOON. THIS WILL ESPECIALLY BE THE CASE
ACROSS THE EASTERN TX PANHANDLE INTO WEST-CENTRAL OK AND PERHAPS
NORTH-CENTRAL OK BY EARLY AFTERNOON.

..GUYER.. 02/12/2013


ATTN...WFO...OUN...LUB...AMA...

[Portastorm]

I think it is worth nothing that the 12z NAM brings a short wave through the backside of the trough this weekend and that it shows this trough fairly strong as compared to its 0z run. Something to watch ... if that shortwave can squeeze out some moisture this weekend, we could see a few sleet pellets or snowflakes as srain has already highlighted.