December: Warm Days & Cool-Foggy Nights To End 2011

[srainhoutx]

The theme for today will be warming temps and increasing winds. Pressure is falling at a rate of 3-5 mb every 3 hours in W TX and moisture levels will increase throughout the day. The atmosphere appears to be capped in the SW areas, but rain and storm chances should increase in the Western areas throughout the day into this evening. There may be some streamer showers late afternoon in the Metro Houston area as strengthening S/SE winds bring moisture N from the Gulf. Areas N of I-10 appear to have the greatest threat for severe weather with damaging winds and some hail chances being the primary threat. An isolated tornado or two cannot be ruled out with stronger storms along and just ahead of the squall line late tonight into early on Tuesday. There have been past cold weather Winter Storms that have caught many by surprise with the December 29, 2006 storm as an analog event that produced 22 tornadoes near Dallas/Ft Worth. This storm appears to be a bit further N, but severe weather chances remain rather high with a Slight Risk for parts of Central/N TX and all of SE TX. We'll need to monitor short range meso guidance for any further 'fine tuning' on this active weather day. Stay Tuned!

[wxman57]

I am not buying the 00Z GFS solution for next Sun/Mon. It's far colder than any other model. Euro/Canadian indicate cold rain with temps in the 40s. Ensembles are similar.

[srainhoutx]

Morning e-mail from Jeff:

Highly active weather pattern continues this week with multiple weather systems to impact the area.

Powerful upper level storm system over AZ this morning will move ENE across NM into KS on Tuesday resulting in full blown blizzard conditions across the TX and OK panhandles. While southward over the rest of TX a potential for strong to severe thunderstorms this afternoon-early Tuesday.

Highly dynamic weather event for the region tonight as the potent SW US upper storm moves into the plains. Low level jet of 40kts extending from KBRO to near KFWD this morning will increase to 50kts this afternoon and shift eastward to our western counties (Matagorda Bay to College Station). Surface to 925mb flow remains backed out of the south into this evening with 60-80kt mid level flow out of the southwest and 100-120kt upper level jet carving into the area this evening. Tremendous wind energy will be in place along with favorable backing of the low level wind fields and turning with height to produce strong wind shear across the region this afternoon into tonight. Low level jet will bring a rapid influx of moisture from the western Gulf with dewpoints rising into the low to mid 60’s by this afternoon and PWS increasing from .8 to 1.5 inches this evening. SPC has outlooked the entire area with a slight risk for severe thunderstorms this afternoon/tonight and this seems reasonable. Only current drawback to a widespread severe event appears to be a general lack of instability with CAPE values of 800-1200 J/kg across most of the area late this afternoon. Tremendous shearing environment may not be utilized if instability is low and updrafts are modest.

With all that said, expect thunderstorms to develop quickly along I-35 early this afternoon as strong forcing overspreads the western edge of the low level jet. Initial storm mode looks supercellular with the best chances for any tornadoes and large hail near/along I-35 this afternoon. Linear forcing along developing cold pool/pre-frontal trough should result in isolated cells growing upscale into a large squall line/MCS by late afternoon as it approaches our western counties. Strong mid level winds digging into the backside of this activity will likely result in bowing line segments and the threat for corridors of damaging winds increasing early this evening as the line moves across SE TX. Feel the best threat for damaging winds will be north of I-10 where the best dynamics and lift will be located. Strong low level shear may also produce a few rotating updrafts either in cells that develop ahead of the line or along the line itself producing a few brief tornadoes. Feel the best tornado threat is just north of our area in the region from NE of Austin to near Centerville. Based on the large amounts of wind energy feel the main threat will be wind damage along the leading edge of the main line with winds of 55-65mph possible.

Strong storm system will move into the Midwest Tuesday with rapid clearing and drying over TX. Dry period will be short lived however in our fast active flow with the next storm already digging into the SW US Tuesday. This storm will move across N MX late Tuesday and toward TX Wednesday. Downstream forcing will generate a lower TX coastal trough with moisture quickly flow northward over a surface cool dome. Surface low will form over the Gulf waters and move NE up the coast late Wednesday into early Thursday. Strong sub-tropical jet aloft on the order of 100kts+ will work with the developing coastal system to produce widespread rains late Wednesday into Thursday. While rains may be widespread amounts will be on the lower side as most of what falls will be light to moderate and confined closer to the coast or offshore. This system will be fast moving and expect rainfall to end by midday Thursday.

May see a brief period of clearing Thursday afternoon/Friday before yet another system arrives toward the weekend. Models are nearly completely different in the handling of this system and its potential to produce precipitation in the cold air mass over the region. One thing looks fairly certain….its looks cold Saturday-Monday with highs possibly only in the 40’s and lows in the 30’s and may be below freezing for some areas under mainly cloudy skies. For now until some kind of agreement forms in the models will go with cloudy and cold conditions with highs near 50 and lows in the 30 with a 20-30% chance of light rainfall both Saturday and Sunday. Forecast for this weekend is extremely low confidence and expect some changes in the coming days.

[srainhoutx]

13Z surface analysis suggest the cold front lies from Raton, New Mexico NE to Hays, Kansas. The H5 low is near Carlsbad, New Mexico moving ENE. There sould be some interesting webcam shot from Dumas later today.

[srainhoutx]

I am not buying the 00Z GFS solution for next Sun/Mon. It's far colder than any other model. Euro/Canadian indicate cold rain with temps in the 40s. Ensembles are similar.

You shall make CAPTAIN CAP LOCKS VERY UNHAPPY.


A week out, I don't buy anything, verbatim, but a random run of the 6Z GFS 252 hours before the 2004 Christmas Eve miracle nailed that within a day, so I refuse to follow logic when it doesn't suit my needs.

[MontgomeryCoWx]

so what you're saying is there's a chance....

I'm traveling Christmas Eve Night from Montgomery to Weimar, then from Weimar to Longview on Christmas Day so that snow on twisterdata maps would make for a picturesque drive.

[singlemom]

so what you're saying is there's a chance....

I'm traveling Christmas Eve Night from Montgomery to Weimar, then from Weimar to Longview on Christmas Day so that snow on twisterdata maps would make for a picturesque drive.

I'm planning to head to Kilgore\Longview on that Monday so I'm rather interested in travel conditions North of Houston (if we don't get snow here - boo). If you guys could keep an eye out on conditions into East Texas we'd appreciate it!

[ticka1]

13Z surface analysis suggest the cold front lies from Raton, New Mexico NE to Hays, Kansas. The H5 low is near Carlsbad, New Mexico moving ENE. There sould be some interesting webcam shot from Dumas later today.

do you have a link to a webcam in Dumas?

[srainhoutx]

13Z surface analysis suggest the cold front lies from Raton, New Mexico NE to Hays, Kansas. The H5 low is near Carlsbad, New Mexico moving ENE. There sould be some interesting webcam shot from Dumas later today.

do you have a link to a webcam in Dumas?

Here you go, ticka1. It can be changed to the Amarillo area or any other location that has webcams supported by TX DOT...

http://its.txdot.gov/ITS_WEB/FrontEnd/d ... llo&t=cctv

[JackCruz]

PRESENT

This week’s weather will be wet.

This is because a strong disturbance in the upper levels of the atmosphere is approaching the upper Texas coast, say forecasters with the Houston/Galveston office of the National Weather Service. As a result the region’s rain chances should increase to at least 70 percent coverage after sunset today, with accumulations of one-half to one inch of rain through early tomorrow morning.

At that time a front should push through the area, leading to gradually clearing skies on Tuesday.

As high pressure moves into the area the rest of Tuesday and the daytime on Wednesday should be calm and cool, with highs around 60 degrees and lows rising from around 40 on Tuesday night to 50 by Wednesday night.

By that time another rainmaking system could be moving toward the area, bringing perhaps a half inch of rain on Wednesday night and Thursday. Friday and Saturday should not see rain, but will remain cool, in the 50s.

The forecast for next Sunday, Christmas Day, looks cool but uncertain. The models still differ between a chance of rain, and a lot of rain, with high temperatures in the upper 40s and lows in the mid-30s over Houston.

If it were about 10 degrees colder we might see snow, but as it is, there’s almost no chance.

http://blog.chron.com/sciguy/2011/12/we ... christmas/

I hope it snows...just to prove him wrong. Ugh.

[TexasMetBlake]

Shreveport MFD:

THE CHRISTMAS FORECAST IS STILL SOMEWHAT UNCLEAR WITH SOME MORE
LIGHT RAIN LOOKING SOMEWHAT LIKELY. ALTHOUGH TIMING AS TO WHEN IS
STILL NOT CONCRETE. AND TO MAKE IT INTERESTING...MODEL TEMPS ARE
ALL OVER THE PLACE AND WILL BEAR WATCHING. THE PATTERN WILL LIKELY
TREND COLDER OVER THE NEXT WEEK AS THE DOOR IS WIDE OPEN FOR FRESH
CANADIAN AIR. GFS AND EURO BRINGING IN A NICE COLD HIGH. THIS PLUS
THE CHANCE FOR MORE PRECIP AROUND THAT SPECIAL TIME WOULD BE
NEAT. AFTER ALL...IT IS ABOUT TO BE OFFICIALLY WINTER.

[TexasMetBlake]

Dallas MFD:

EXTENDED FORECAST REMAINS OF VERY LOW CONFIDENCE DUE TO WIDESPREAD
DISAGREEMENT IN HOW SEVERAL VORT LOBES INTERACT WITH EACH OTHER.
REGARDLESS OF THE DETAILS...THE SYNOPTIC PATTERN SUGGESTS WITH
HIGH CONFIDENCE THAT IT WILL BE COLD FOR THE HOLIDAY WEEKEND. WILL
NEED BETTER INTER-MODEL AND RUN-TO-RUN CONSISTENCY BEFORE
ENTERTAINING THE POTENTIAL FOR PRECIPITATION.

[singlemom]

Thanks, Candy Cane. Duh....should've consulted NWS in Shreveport and Dallas. *blush*

[Snowman]

It's awesome that there is even a chance for something interesting this coming weekend! I know it's not probable but you never know maybe we can pull another christmas miracle

[srainhoutx]

Just a quick mention regarding Thursday. The GFS suggests another round of rain with a coastal trough and a fast moving short wave as well as another front passing...

[redneckweather]

As I have said already, the trend is for colder air to settle in for the weekend and the beginning of next week...and I think the models will continue to move in that direction. Maybe some wintry precip? I hardly doubt it. All I have to do for a reality check is go back to this past February where when my heart was mud holed something fierce. Kind of like my Bama boys losing at home to LSU this year. That will NOT happen again. Roll Tide!!

[srainhoutx]

The SPC extends the Slight Risk a bit further N to include the Dallas/Ft Worth Metroplex. All of SE TX remains in the Slight Risk area...

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1025 AM CST MON DEC 19 2011

VALID 191630Z - 201200Z

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON INTO TONIGHT
ACROSS PORTIONS OF NRN/CNTRL/ERN TX...

...SYNOPSIS...

EWD-MOVING UPPER LOW CENTERED NEAR EPZ WILL TURN MORE NEWD THIS
PERIOD IN RESPONSE TO THE PROGRESSION OF 80-90 KT MIDLEVEL JET
STREAK FROM NRN MEXICO INTO NRN TX/ERN OK. THIS EVOLUTION WILL
RESULT IN A CORRIDOR OF 12-HR HEIGHT FALLS /500 MB/ AOA 100 M
SPREADING FROM ERN NM/WRN TX INTO KS/OK. IN THE LOW LEVELS...
SURFACE LOW OVER ERN NM WILL DEVELOP ACROSS THE SRN TX PNHDL THIS
AFTERNOON INTO CNTRL OK BY 20/12Z. THIS LOW PRESSURE WILL BE
ACCOMPANIED BY A PACIFIC FRONT THAT WILL ADVANCE EWD ACROSS
WRN/CNTRL TX AND SWRN/S-CNTRL OK.

...SRN PLAINS...

SCATTERED ELEVATED TSTMS OVER PARTS OF W-CNTRL/NWRN TX INTO
WRN/CNTRL OK WILL MOVE/DEVELOP EWD/NEWD TODAY IN CONJUNCTION WITH A
LEAD VORTICITY MAXIMUM EJECTING NEWD IN ADVANCE OF PRIMARY
UPPER-LEVEL SYSTEM. LIMITED ELEVATED INSTABILITY SHOULD PRECLUDE A
SEVERE HAIL THREAT WITH THIS ACTIVITY.

BY MID/LATE AFTERNOON...LATEST CONVECTION-ALLOWING AND MESOSCALE
MODEL GUIDANCE INDICATES AN INCREASED LIKELIHOOD FOR SURFACE-BASED
TSTM DEVELOPMENT ALONG PACIFIC FRONT INVOF OF THE I-35 CORRIDOR OF
NRN/CNTRL TX. HERE...INCREASING BOUNDARY LAYER MOISTURE CONTENT
WILL BE OFFSET TO A DEGREE BY WIDESPREAD CLOUDS WITH MLCAPE VALUES
RISING TO 500-1000 J/KG. BUT...GIVEN THE STRONG FORCING FOR ASCENT
AND STRENGTHENING LOW- AND DEEP-LAYER SHEAR /I.E. ESRH OF 200-300 M2
PER S2 AND EBS OF 45-55 KT/...THE SETUP WILL FAVOR THE DEVELOPMENT
OF ORGANIZED STORM MODES INCLUDING SUPERCELLS WITH A RISK FOR A FEW
TORNADOES...DAMAGING WINDS AND HAIL.

ELSEWHERE...ISOLATED...LOW-TOPPED TSTMS WILL BE POSSIBLE THIS
AFTERNOON OVER THE SRN TX PNHDL INTO FAR SWRN OK BENEATH MIDLEVEL
COLD CORE AND INVOF OCCLUDING SURFACE LOW. HERE...STEEPENING LAPSE
RATES WILL YIELD WEAK CONVECTIVE INSTABILITY WITH THE STRONGEST
STORMS CAPABLE OF SOME HAIL...POSSIBLY APPROACHING SEVERE LEVELS.

[srainhoutx]

Impressive storm taking shape...

[wxman57]

12Z GFS not as happy as 0Z GFS. Nowhere near as happy out at Christmas.

Yep, here's the latest meteogram for IAH. It was only one goofy run of the GFS that had anything interesting for us next weekend. Don't count in anything but cool/cold and rain.

[ticka1]

I will take the rain. Would rather have snow but rain is good too. How much raintfall we looking at?