Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 3

[wxmx]

If the strong S/W energy embedded in the long wave trough along the W coast doesn't cutoff around Baja, it could get very interesting in around 8-9 days... another Winter storm for the S/C Plains?

[Ed Lizard]

If the strong S/W energy embedded in the long wave trough along the W coast doesn't cutoff around Baja, it could get very interesting in around 8-9 days... another Winter storm for the S/C Plains?

Tomorrow is the 3rd anniversary of the 2008 Houston Snow Miracle.

PUBLIC INFORMATION STATEMENT…CORRECTED

NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX

1158 AM CST THU DEC 11 2008

…SNOW FALL TOTALS FOR 10 DECEMBER 2008…

A COLD UPPER LEVEL LOW PRESSURE SYSTEM MOVED ACROSS SOUTHEAST

TEXAS YESTERDAY AND HAS PRODUCED A BROAD AREA OF SNOWFALL FOR

EARLY DECEMBER. THIS TIES THE MARK FOR THE EARLIEST SNOW FALL IN

THE HOUSTON AREA FOR DECEMBER. IT HAD ALSO SNOWED ON DECEMBER 10

IN 1944. LIGHT SNOW FELL DURING THE MORNING OVER PARTS OF

WASHINGTON…BURLESON AND BRAZOS COUNTIES ON DECEMBER 10TH. SNOW

REDEVELOPED DURING AFTERNOON AS THE UPPER LEVEL LOW PRESSURE

MOVED INTO THE HOUSTON AREA. SOME AREAS ACROSS THE REGION SAW A

CHANGE OF RAIN AND SLEET TO SNOW BY THE EVENING HOURS. SNOWFALL

WAS AT ITS HEAVIEST BETWEEN 5 PM AND 10 PM LAST NIGHT MAINLY EAST

OF AN INTERSTATE 45 LINE. SNOW FALL AMOUNTS RANGED FROM A TRACE

OVER PARTS OF WESTERN BRAZORIA…HARRIS AND MONTGOMERY COUNTIES

TO AS MUCH 2 TO 3 INCHES IN EASTERN HARRIS COUNTY. TRACE TO ONE

INCH AMOUNTS FELL ON GALVESTON ISLAND WITH GENERALLY AN INCH TO

TWO INCHES OF SNOW FALL FOR GALVESTON COUNTY. THE HEAVIEST SNOW

FALL WAS IN A BAND FROM CHAMBERS COUNTY TO POLK COUNTY WHERE

SOME AREAS SAW AS MUCH AS 4 TO 5 INCHES OF SNOW.

WHEN DID IT SNOW LAST? SNOW FLURRIES FELL ACROSS THE EXTREME

NORTHERN PARTS OF THE REGION ON MARCH 7TH 2008 BUT THE LAST

MEASURABLE SNOW OCCURRED ON APRIL 7TH 2007 NORTH OF A CALDWELL TO

LIVINGSTON LINE. ONE TO TWO INCHES OF SNOW FELL ON THAT SATURDAY

BEFORE EASTER.

THE LAST MEASURABLE SNOW TO FALL IN THE HOUSTON AREA FELL ON

CHRISTMAS EVE IN 2004. SNOW AMOUNTS WERE A TRACE AT

INTERCONTINENTAL AIRPORT…BUT SOUTHERN SUBURBS LIKE PEARLAND…

WEBSTER AND CLEAR LAKE RECEIVED 2 TO 3 INCHES OF SNOW. FURTHER

SOUTH A BAND OF HEAVY SNOW AFFECTED WHARTON…FORT BEND AND

BRAZORIA COUNTIES.

[Quixotic1]

I had to post the TwisterData.com's or whatever the name of the site is snow accumulation on my FB page. Ian appreciated it.

I fear great boredom except for random craziness from the GFS beyond the wave number truncation for a while, 8 days of existential unexcitement until the first hint of relief, Temple versus Wyoming in the Gildan New Mexico Bowl.

That and a stormy pattern for Northern Europe.

It's nice to see that TwisterData stuck with my rudimentary 10/1 snow ratio. 2" for Houston area ain't bad.

[DoctorMu]

It's nice to see that TwisterData stuck with my rudimentary 10/1 snow ratio. 2" for Houston area ain't bad.

3-4 in in CLL. The kids would freak.

[Quixotic1]

If the strong S/W energy embedded in the long wave trough along the W coast doesn't cutoff around Baja, it could get very interesting in around 8-9 days... another Winter storm for the S/C Plains?

3-4 in in CLL. The kids would freak.

While shuffling with placement, that storm has been there in some form or another for 4 runs now. Somebody give me a reason not to get excited. I'm about to weenie out.

[Srain]

I'll say one thing. The GFS continues to be persistent regarding wintry mischief chances for Texas next weekend. If the other guidance begins to 'bite', we may have something to watch early next week…

[andyhb]

18z GFS's moisture/instability advection off of the Gulf made me bat an eyelash or two...

[wxmx]

Interesting the rain pattern this year IMBY...it's either all or nothing, there have been no normal quarter, half or even one inch precipitation events... it's either 2", 4", 5"... I have received almost nil since the 5" rain a few months ago and now it looks like it will be close to 2", which is a freak event for met winter (DJF)...last time I remember of 2"+ was.... well, I don't remember there has been one since I moved here Jan '94...

[Srain]

The front has pushed to the Coastal Counties this morning and cloudy and cool conditions with a slight chance of very light rain/drizzle possible down near Matagorda Bay. There is a weak short wave to our W that should pass later today into tonight with perhaps some very light drizzle as the noisy STJ remains close by. A warming trend should begin early next week bring us back to seasonal temps. The next chance of rain appears to be on Thursday as a storm system begins to track E from the W Coast trough. The storm track appears to be across the TX Panhandle into the Southern/Central Plains. The best chances for heavier rains/storms look to be up in N TX, but rain chance should increase as a Pacific front swings through. As the storm system tracks across the Plains, a potent winter storm looks to tap into the northern stream and much colder air and a reinforcing cold front dives S next Saturday. Guidance continues to struggle with the pattern as yet another upper low digs S into Arizona and sets the stage for yet another over running event. We'll need to monitor this situation early next week as we could see a similar situation as we saw last weekend with very chilly temps, over running precip and even wintry mischief for W TX, the Panhandle and possibly as far S as N Central TX. Sound familiar? We are stuck in this type of pattern and once again expect changes in the forecast. High pressure ridging across the Gulf of Alaska (+PNA) as well as deep troughing across the West and Central CONUS and upper air storms dropping into CA/AZ/Baja Region look to persist.

[Srain]

Some might chilly air is poised to spill S next weekend with a shallow sharp Arctic front. The 12Z guidance suggests that once the storm system tracks NE across the Plains mid week, that cold air will be pulled S along the lee side of the Rockies. Now we'll have to see what happens with the upper air disturbance forecast to drop S into the SW. The 12Z Euro raises an eyebrow and if the guidance is under estimating the strength of that cold air, then things could become interesting for parts of N MX/Texas/N LA and points to the N and E.

[Ed Lizard]

Haven't seen any way near as many sleet/freezing rain events in Houston during the over a decade I lived here as my much shorter time in Austin, but what I used to look at, fairly shallow cold air, such that the 0ºC 850 mb line is South of the 1000-500 mb 5400 thickness line, with magic (I don't need to remember it, PSU e-Wall colors it if it displays it) 700 mb thickness line in between, and the trough axis still West of Houston, well, the Euro map above bears some resemblance.

[David Reimer]

This afternoon's discussion from Fort Worth hints at winter mischief next weekend. I should also point out we may be dealing with some severe weather on Wednesday. A busy weather week ahead for Texas!

THERE IS GOOD AGREEMENT AMONG THE MODELS WITH THE SYNOPTIC UPPER LEVEL PATTERN AT 144 HRS. A LARGE/BROAD POSITIVE TILTED 200MB TROUGH EXISTS FROM THE HUDSON BAY TO LAS VEGAS. THE 500 MB TROUGH IS ANCHORED BY A SLOW MOVING UPPER LEVEL LOW OVER THE SW US...WITH THE NORTHERN PART OF THE 500MB TROUGH DETACHED AND PROGRESSIVE ACROSS THE NORTHERN PLAINS. THIS UPPER PATTERN RAISES RED FLAGS FOR THE POTENTIAL OF WINTER WEATHER...BECAUSE IT SIGNALS THAT MAIN INGREDIENTS...COLD AIR AND LIFT...WILL BE GIVEN THE CHANCE TO MINGLE IN OUR REGION. MODELS BECOME UNTRUSTWORTHY REGARDING THE SPECIFICS BY DAY 7-10...AND WE HAVE SEEN THE GFS BOUNCE AROUND WITH ITS HANDLING OF THE WESTERN LOW. THE NORTHERN PIECE OF THE TROUGH IS NOT QUITE AS STRONG/DEFINED AS I WOULD LIKE TO SEE...SO THIS SUGGESTS COLD AIR MAY BE THE LIMITING FACTOR FOR ANY WINTER WEATHER. THIS LIKELY SIGNALS MORE ICE THAN SNOW...WITH THE NW PART OF THE CWA FAVORED SOMETIME BETWEEN SATURDAY AND NEXT MONDAY. OBVIOUSLY WITHOUT GOOD MODEL CONSISTENCY AT THIS TIME RANGE WILL KEEP FORECAST ALL RAIN SATURDAY AND CONTINUE TO WATCH.

[andyhb]

This afternoon's discussion from Fort Worth hints at winter mischief next weekend. I should also point out we may be dealing with some severe weather on Wednesday. A busy weather week ahead for Texas!

Yeah, I read the discussion on your website.

Pretty far out, but the dewpoints and wind profiles look solid.

[David Reimer]

Yeah, I read the discussion on your website.

Pretty far out, but the dewpoints and wind profiles look solid.

Thanks!

The 12Z GFS has come in with higher instability values so my confidence in some severe weather has increased, but we're still several days out. It seems that OUN is confident on the severe weather chances as they're already putting headlines out.

[andyhb]

Thanks!

The 12Z GFS has come in with higher instability values so my confidence in some severe weather has increased, but we're still several days out. It seems that OUN is confident on the severe weather chances as they're already putting headlines out.

Yeah, just checked that out, LLJ nicely developed across these areas on Wednesday.

[Srain]

The 00Z operational GFS flipped to a much warmer solution regarding next weekend. In fact it would suggest temps in the 70's. The GFS ensembles paint a much different picture with colder temps. The Euro/Canadian remain rather 'chilly' but suggest the upper air disturbance (5H) lingers longer to our W with over running conditions, for what it's worth. But as it has been mentioned many times during this current pattern, the guidance is struggling beyond the 3-5 day range and there is little confidence in any forecast in the medium/long range. On another note, I see that many S Texas locations reported over 2 inches of rain yesterday. That is great news regarding the drought. An active week appears to be ahead with warming temps, severe weather chances to our N in the Panhandle/OK and N Central TX with a couple of fronts for the week ahead. The pattern looks to remain very active with no real change on the horizon.

[andyhb]

In-depth Day 4-8 regarding next week's systems from SPC:

DAY 4-8 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0355 AM CST SUN DEC 11 2011

VALID 141200Z - 191200Z

...PREDICTABILITY TOO LOW TO DELINEATE A REGIONAL SVR RISK AREA...

MEDIUM RANGE MODELS INDICATE THAT A VIGOROUS UPPER IMPULSE LIFTING

OUT OF THE SOUTHWESTERN STATES BY MIDWEEK WILL CONTRIBUTE TO

SIGNIFICANT SURFACE CYCLOGENESIS FROM THE CENTRAL PLAINS INTO THE

UPPER MIDWEST WEDNESDAY AND WEDNESDAY NIGHT. WITH THIS EXPECTED TO

COINCIDE WITH A SUBSTANTIVE INFLUX OF MOISTURE FROM THE WESTERN GULF

OF MEXICO...AN INCREASE IN CONVECTIVE POTENTIAL CERTAINLY SEEMS

LIKELY. SOME GUIDANCE...THE 11/00Z ECMWF IN PARTICULAR... SUGGESTS

THAT A DRY LINE OR DRY LINE TYPE STRUCTURE COULD FORM BENEATH A

MID-LEVEL DRY SLOT ACROSS PARTS OF CENTRAL INTO EASTERN OKLAHOMA AND

KANSAS BY LATE WEDNESDAY AFTERNOON...PROVIDING A POSSIBLE FOCUS FOR

SUPERCELL DEVELOPMENT IN THE PRESENCE OF STRONG VERTICAL SHEAR.

HOWEVER...EVEN IN THIS CASE...BOUNDARY LAYER DESTABILIZATION ALONG

AND AHEAD OF THE SURFACE FEATURE INTO PARTS OF ARKANSAS AND MISSOURI

REMAINS UNCLEAR. IT SEEMS MORE LIKELY THAN NOT THAT MOISTURE RETURN

ABOVE A RESIDUAL COOL BOUNDARY LAYER WILL PROMOTE CONSIDERABLE LOW

CLOUD COVER AND PRECIPITATION... MAINTAINING STABLE NEAR SURFACE

CONDITIONS. GIVEN THIS UNCERTAINTY...ALONG WITH LINGERING

DISCREPANCIES/SPREAD AMONG THE MODELS AND MODEL

ENSEMBLES...PREDICTABILITY REMAINS TOO LOW TO CONFIDENTLY ASSESS THE

POTENTIAL FOR A REGIONAL SEVERE WEATHER OUTBREAK. THIS UNCERTAINTY

GROWS THROUGH THE REMAINDER OF THE PERIOD...AS SHORT WAVE

DEVELOPMENTS WITHIN THE PREVAILING SPLIT UPPER FLOW PATTERN BECOME

INCREASINGLY UNCLEAR.

..KERR.. 12/11/2011

[DFWWeather]

Around DFW, there will be no severe weather on Wednesday of this week. The boundary layer will remain too stable for that. There could be some strong storms, but let's not overplay that. The severe weather button is just triggered too much for this area. I would be more concerned with a heavy rain event, especially with the abnormal PWAT values for December.

What is more likely for this time of year, and something to watch for, is the possibility of winter precip the weekend of the 17th. Nearly all of the GFS ensembles are entrenching Texas in modified Arctic air that weekend. However, I will note the ECMWF and GFS has suddenly shifted warmer that weekend as of 0z this morning, an odd, sudden shift. The mean upper pattern, as discussed yesterday by NWS, shows an elongated trough from the Hudson bay down into the desert southwest. Pattern recognition alone points to mischief in this area. The only thing I would say about this whole scenario is the ingredient of cold air. I mean how much is there really to tap into? Typically, I would like to see a stronger source of cold air.

[Srain]

The big issue arising from the 12Z guidance is the potential for precip, and perhaps a lot of it. With a zonal upper air pattern and a slow moving cut off low to our W in S CA/AZ, copious moisture appears to be on tap from the Gulf as ridging develops near FL creating an onshore flow. The Wednesday night/Thursday front appears to stall across Central and SE TX. This could be a big focal point for some moderate rains. The front appears to hang across the area throughout next weekend before the upper air disturbance and attending multiple short wave energy begins to move to the E early in the week before Christmas. There is still some uncertainty, but areas N of the boundary could get rather chilly and as the upper air (cold core) low slowly drags E, colder temps should finally push the front with a re-inforcing shot of modified arctic air S into the NW Gulf. We have an active pattern ahead and expect changes and 'fine tuning' throughout the week.

[andyhb]

That system from 126 to 192 hrs on the 12z GFS bears watching as well.

[Ed Lizard]

What happened to the cold on today's models. I will note (as I saw on FB and on a main forum page) that JB, LC and DT, the Three Hoarsemen of the Apocalypse, had all been on the strat warming/mondo cold bandwagon, for reasons I don't know.

[Quixotic1]

What happened to the cold on today's models. I will note (as I saw on FB and on a main forum page) that JB, LC and DT, the Three Hoarsemen of the Apocalypse, had all been on the strat warming/mondo cold bandwagon, for reasons I don't know.

Ugh. I think it's safe to say the current pattern is giving the models fits. It was looking so consistent for awhile.

If there's an SSW going on, I'll be darned if I can see it.

[wxmx]

There's no SSW going on...and not in the near future. There's some slight warming, but nothing dramatic...not even moderate on sight....yet

[Ed Lizard]

Just saw from a red tagger on the main forum strato warm (which may degrade to a climate change discussion) that KNYC had its first freeze today.

Not sure what is bigger, IAH beating DC for snow or NYC for the first freeze...

[Srain]

A very unsettled pattern is shaping up in a very un La Nina like weather regime creating a lot of havoc in forecasting. Clouds and possible light rain/drizzle look to be in order before a warm front retreats N on Tuesday. To our W, another upper air disturbance is taking shape near S CA. This feature should begin to head N and E into the Upper Mid West on Wedensday/Thursday allowing a frontal boundary to sag S into our area. Shower and even some rumbles of thunder may be possble as the front/trough approaches. The fly in the ointment is where does this boundary stall? Guidance is in good agreement that a much stronger upper low will drop S into CA/AZ and possibly as far S as the Baja Region. SW flow aloft will likely allow over running conditions to become established and rain chances look to remain in the picture throughout the weekend. Early indications are the upper low will remain stationary or move extremly slowly E next Monday and Tuesday. There are some indications that a potent storm system will develop as moisture stream E along the noisy sub tropical jet with multiple disturbances. All in all after a bit of moderation in temps the next couple of days, a return cloudy/cool and dreary conditions appears to be in the works. This is still a very volatile forecast and further 'fine tuning' can be expected.

[DoctorMu]

^Yeah, I hope this La Nina remains a cross-dresser. Bring on the dreary, rainy day and then some insect-killing cold!

[DFWWeather]

12z ECMWF painting a very interesting scenario next Monday/Tuesday for DFW and surrounding North Texas. Given the much talked about elongated positively tilted trough extending from Hudson Bay into the Great Basin, would not be surprised for some type of wintry precipitation associated with this next massive storm system, especially if the upper-low digs as far south as depicted by the ECMWF. GFS may be too fast with this next system. Gonna be a interesting forecast week!

[bubba hotep]

Yeah, Euro wouldn't take too much tweaking to get the good stuff over in DFW. Wonder if the gfs will come back around to what it what is was smoking a few days ago.

[Quixotic1]

The problem with any upcoming wintry scenario, is the lack of cold. Don't see much of it NA.

[Srain]

We have an active period ahead and today will be the quiet one for most of the next 7 days. The SPC has a Slight Risk for severe storms for parts of Central and NE TX on Wednesday. An upper air disturbance will begin moving NE from S CA/AZ tonight bringing mountain snows to the higher elevations with rain/freezing rain chances into the Central Plains. Further S, thunderstorms with damaging winds and even some hail across portions of Central/NE TX are possible. A Pacific front should slide S and stall near the coast on Thursday allowing for over running rain chances through Saturday.

Another more potent upper air disturbance will dive S into the Desert SW and meander over the weekend before ejecting E. The timing of this second disturbance is in question, but all guidance suggest a closed cold core low will trek across N MX into TX. At the same time a powerful northern stream storm system will trek E near the Canadian/US border dropping some arctic air S. As the SW storm wraps up and begins to slowly move E, that cold air will spill S through the Plains. Wintry mischief is looking likely for the Southern Rockies. As the system enters TX, rains and evn some heavy storms are possible in the warm sector. Wintry mischief looks possihble for parts of W/The Panhandle/N Central And N TX as the upper low passes to the E. While it is still diffiicult to determine the track of this feature, early indications are it may be a bit further S. Cold air with a strong front will be associated with this storm and as of now it appears that we are once again moving into a rather cold pattern.

The sub tropical jet remains noisy as well as srorms moving across the N Pacific. The pattern shows no real sign of relaxing, so it appears we will remain in an unsettled situation for some time on into the Christmas Holiday period.