Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 2

[Srain]

Discuss...at the suggestion of Ian, I'll add New Mexico to our discussions as well...

[Srain]

EWX aleady hinting at major changes ahead...

AREA FORECAST DISCUSSION...UPDATED

NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX

1025 AM CST SUN FEB 6 2011

.UPDATE...

HAVE UPDATED THE 1ST PERIOD TEMP/DEWPOINT/WIND/SKY GRIDS BASED ON

THE CURRENT OBSERVATIONS AND ANTICIPATED TRENDS BASED ON THE 12Z

NAM SOLUTION.

&&

.DISCUSSION...

LATE THIS MORNING WEST TO SOUTHWEST WINDS WERE MIXING TO THE SFC

IN ADVANCE OF THE PACIFIC COLD FRONT. THE WEST TO SOUTHWEST

TRAJECTORY IN THE BOUNDARY LAYER WILL LEAD TO A PLEASANT AND DRY

AFTERNOON. THE WINDSHIFT ASSOCIATED WITH THE PACIFIC FRONT HAS

OCCURRED AT OZONA AND COMANCHE. THUS EXPECT THE PACIFIC FRONT

TO ENTER THE HILL COUNTRY THIS AFTERNOON.

THE UPCOMING WINTER PCPN EVENT. THE 12Z NAM HAS THE ARCTIC FRONT

MOVING INTO THE HILL COUNTRY AROUND 12Z WEDNESDAY. IF OTHER MODEL

SOLUTIONS AGREE WITH THIS TIMING...WE WILL HAVE TO DO A MAJOR

REVISION OF THE FCST FOR TUESDAY NIGHT AND WEDNESDAY IN REGARDS TO

TEMPS AND PCPN TYPE.

[Srain]

HPC:

...WAVE DROPPING THROUGH THE WESTERN STATES EARLY DAY 2...

PRELIMINARY PREFERENCE: PENDING 12Z/06 ECMWF

THE NAM...GFS...GEM GLOBAL...AND UKMET ARE ALL LESS SHARP WITH

THIS WAVE ONCE IT TRANSLATES TO THE SOUTHERN PLAINS EARLY DAY 3

THAN THE 00Z/06 ECMWF. CONSIDERING THE TRENDING THE MODELS HAVE

SHOWN WITH THE HANDLING OF THIS SYSTEM...WILL WAIT FOR THE 12Z/06

ECMWF TO MAKE A CALL HERE.

...ARCTIC FRONT DIPPING INTO THE UPPER MIDWEST DAY 3...

PRELIMINARY PREFERENCE: PENDING 12Z/06 ECMWF

THE NAM AND UKMET ARE SLIGHTLY LESS AMPLIFIED WITH THIS WAVE THAN

THE 00Z/06 ECMWF...WITH THE GFS AND GEM GLOBAL OFFERING THE

FLATTEST OF THE SOLUTIONS. WITH THE ONGOING SPREAD IN THE

MODELS...WILL WAIT FOR THE 12Z/06 ECMWF TO MAKE A CALL HERE.

[Srain]

Euro looks a tad slower, but N TX and the Panhandle look likely for wintry weather...

[msp]

already 66F here, shooting past the forecast high

[David Reimer]

already 66F here, shooting past the forecast high

Why don't you send some of that up this way? I'd love to have a day of T-Shirt weather before I have to go back into the snow.

[David Reimer]

Euro looks a tad slower, but N TX and the Panhandle look likely for wintry weather...

Something about that look makes me weary of another ice storm here in North Texas. Assuming the surface temperatures outrun model guidance like last Tuesday, I might as well just go buy a generator.

[Srain]

Why don't you send some of that up this way? I'd love to have a day of T-Shirt weather before I have to go back into the snow.

66 down here as well. Pool season is nearing after this week...

[bubba hotep]

EURO qpf courtesy of SEMIweather in the OK/MO/Arky thread:

DFW: 0.35" ...likely 0.12" of rain then 0.23" of snow

12z Canadian

[bubba hotep]

The GFS Ens is starting to make me nervous. I am really ready for Spring and hope that cold air stays locked up in the far North!

[DFWWeather]

EURO qpf courtesy of SEMIweather in the OK/MO/Arky thread:

DFW: 0.35" ...likely 0.12" of rain then 0.23" of snow

12z Canadian

Rain will likely be frozen as the surface temperatures will be at or below freezing way ahead of the 0°C H85 line in this setup. Again, think there will be more sleet with this system as is always the case in these wedge Arctic airmasses initially. The NAM was on to this this morning. Also, this upper system may move slower than the one last week which would change a whole lot of things in terms of accumulation. Wouldn't be surprised to see a Winter Storm Watch go up at DFW by tomorrow afternoon, if trends hold.

[Srain]

15Z SREF will raise an eyebrow or two.

[Srain]

Not much, if any change with the HGX afternoon update...

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX

302 PM CST SUN FEB 6 2011

.DISCUSSION...

COLD FRONT EXTENDING FROM JUST NORTHWEST OF ACT TO THE HILL

COUNTRY. FRONT EXPECTED TO PUSH ACROSS NW ZONES LATE THIS

AFTERNOON TO EARLY EVENING...TO HOUSTON METRO AREA MID EVENING

AND SHOULD APPROACH GALVESTON LATE EVENING. WE SHOULD SEE A RATHER

THIN LINE OF CONVECTIVE ACTIVITY NEAR/ALONG BOUNDARY AS IT MOVES

TO THE SOUTHEAST WITH ACTIVITY MAINLY OCCURRING OVER EASTERN

SECTIONS OF CWFA THIS EVENING. WEAK ISOLATED THUNDERSTORMS

POSSIBLE CONSIDERING MODEL VERTICAL PROFILES. SURFACE ANALYSIS

THIS MID AFTERNOON INDICATE A CONVERGING FLOW FROM JUST WEST OF

GLS TO WESTERN LIBERTY COUNTY WITH RELATIVELY COOL SE FLOW OVER

THE FAR SE COUNTIES DUE TO WINDS TRAVERSING COOL SHELF COASTAL

WATERS. NEAR 70 TO THE MID 70S WERE NOTED OVER REST OF CWFA WITH

THE HIGHER READINGS OVER THE SW ZONES WITH BREEZY SW FLOW. LOW

CLOUDS WILL OVERSPREAD REGION BEHIND THE FRONT LATER TONIGHT BUT

SHOULD BREAK UP DURING MORNING HOURS MONDAY. SURFACE HIGH WILL

OVER REGION MONDAY AND THEN MOVE EAST MONDAY NIGHT AND TUESDAY

USHERING RETURN OF ONSHORE FLOW. THIS WILL BE FOLLOWED WITH

INCREASING MOISTURE LEVELS. A STRONG COLD FRONT IS INDICATED TO

PUSH ACROSS OUR REGION WEDNESDAY WITH FRONT EXPECTED TO MOVE

ACROSS NW ZONES MID DAY TO EARLY AFTERNOON...REACHING THE COAST

NEAR SUNSET. TEMPERATURES WILL START TO DURING AFTERNOON HOURS

WEDNESDAY ONCE FRONT PASSES THROUGH. MODELS INDICATE PWATS

INCREASING TO AROUND 1.1 INCHES SW PORTIONS OF CWFA AHEAD OF

FRONT. SURFACE DEWPOINTS NOT REACHING 60 EXCEPT SW PORTIONS AND

ONLY FOR A SHORT PERIOD. VERTICAL PROFILES INDICATE LIFTED INDEX

VALUES REMAINING POSITIVE. WE SHALL SEE WHAT LATER MODEL RUNS

WOULD INDICATE. FOR NOW WE CONTINUED WITH CHANCE OF RAIN WEDNESDAY

WITH POSSIBLE FREEZING LIGHT DRIZZLE FAR NORTHERN ZONES LATE IN

THE AFTERNOON/EARLY EVENING. IT SHOULD DRY QUICKLY AT MID/UPPER

LEVELS DURING THE EVENING HOURS. EARLY THURSDAY MORNING WILL SEE

TEMPERATURES DROPPING TO THE MID 20S NORTHERN PORTIONS OF CWFA

WITH REMAINDER OF CWFA PROBABLY HAVING MINS IN THE UPPER 20S TO

THE LOWER 30S. SURFACE HIGH WILL PREVAIL OVER REGION LATE IN THE

WEEK WITH ONSHORE FLOW RETURNING SATURDAY AS HIGH SHIFTS TO THE

EAST. WARMING TREND AND INCREASE IN LOW LEVEL MOISTURE CAN BE

EXPECTED THEN.

[msp]

was 74F here... so gorgeous outside

[Witness Protection Program]

Looks like any rain won't reach the Super Bowl until around kickoff, keeping fans dry. But what the hell is wrong with the DFW office of the NWS? Just seem to mail it in lately. Webpage page had the forecast hi at 42 before noon while it showed a current temp of 50, while at 4pm again showing a current temp of 50 they had updated their forecast hi to...45. Way to pay attention. And of course it is taking an average of 5 or 6 refreshes to even get the local webpage to load. As it often has for months.

[bubba hotep]

18z GFS spits out about the same amount of qpf as 12z up this way but looks to have a better temp profile with more of that qpf possibly falling as snow. Looks like it is going to be a really tight gradient as you head south into the metroplex. For the most part this winter the far NE burbs have been in the jackpot zone and it looks like we could close out the winter that way

Either way, I'll be glad to push into some warmer weather and get back to a regular training schedule.

[bubba hotep]

Looks like any rain won't reach the Super Bowl until around kickoff, keeping fans dry. But what the hell is wrong with the DFW office of the NWS? Just seem to mail it in lately. Webpage page had the forecast hi at 42 before noon while it showed a current temp of 50, while at 4pm again showing a current temp of 50 they had updated their forecast hi to...45. Way to pay attention. And of course it is taking an average of 5 or 6 refreshes to even get the local webpage to load. As it often has for months.

Really? I think they have been pretty good through what has been a pretty wild winter. This last snow was really hard to predict and none of the models caught on until the NAM started trending hard towards a big snow over the last 12 to 18 hours. I think their daily discussions have been right on and they have done a good job of highlighting the threats without being overly conservative or going overboard.

[Srain]

A lot of reports of small hail tonight in SE TX...

SPECIAL WEATHER STATEMENT

NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX

756 PM CST SUN FEB 6 2011

TXZ178-179-200-070300-

LIBERTY-POLK-SAN JACINTO-

756 PM CST SUN FEB 6 2011

...SIGNIFICANT WEATHER ADVISORY...

AT 748 PM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED

STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 30 MILES NORTHEAST

OF CLEVELAND TO CLEVELAND...MOVING EAST AT 25 MPH.

UP TO DIME SIZE HAIL...ARE POSSIBLE WITH THESE STORMS.

LOCATIONS IN THE PATH OF THESE STORMS INCLUDE...TARKINGTON PRAIRIE...

SEGNO...ROMAYOR...MOSS HILL...LIBERTY...KENEFICK...HARDIN...DAYTON

LAKES AND CLEVELAND.

[bubba hotep]

00z GFS continues the slow shift back towards the south trend but also comes in as one of the driest GFS runs in a while. Pretty wild differences b/w the NAM and GFS esp. for our friends from Fayetteville up into NE Ok.

[David Reimer]

00z GFS continues the slow shift back towards the south trend but also comes in as one of the driest GFS runs in a while. Pretty wild differences b/w the NAM and GFS esp. for our friends from Fayetteville up into NE Ok.

The 0Z NAM keeps all snow north of the red river while the GFS gives a few inches to the metroplex. At this point, I'm leaning towards the GFS/SREF solution which seems to be on a more consistent track basis as this point. Fort Worth seems to be agreeing, while maintaining the wording for a winter weather event. Luckily, I've promised myself I won't even try to go in depth with this system until tomorrow. There is simply no way to forecast what its going to do yet, we're still 2 days out. I'll make my first call after the 12Z data comes in and we get the upper air grid to sample some of this system, even though that didn't help for the past two storms. They still surprised North Texas anyway.

[bubba hotep]

The 0Z NAM keeps all snow north of the red river while the GFS gives a few inches to the metroplex. At this point, I'm leaning towards the GFS/SREF solution which seems to be on a more consistent track basis as this point. Fort Worth seems to be agreeing, while maintaining the wording for a winter weather event. Luckily, I've promised myself I won't even try to go in depth with this system until tomorrow. There is simply no way to forecast what its going to do yet, we're still 2 days out. I'll make my first call after the 12Z data comes in and we get the upper air grid to sample some of this system, even though that didn't help for the past two storms. They still surprised North Texas anyway.

Yeah, its been a wild week. I think we will continue to see a south trend with the GFS but any additional snow will just be gravy at this point. This last system ranks up there in my Top 5 all-time with Feb 2003 in DC and the storms last year in DC. I need to brush up on my Texas weather history but it has to be pretty rare to get a snow storm going in this part of the country that starts out in the low 20s and has such high ratios.

[bubba hotep]

One last comment on the 00z GFS, while it does decrease our qpf it appears to come in with a better temperature profile and I think we see more qpf as snow.

[bubba hotep]

Watches are up for the Metroplex!

[Srain]

The 00Z Euro does raise an eyebrow for folks in W/Central and even parts of SE TX as well...this could well be a very close call...

[Srain]

Morning e-mail from Jeff:

Impressive warm up over the weekend as old arctic high moved eastward.

Temperatures rebounded some 40 degrees between Friday and Sunday afternoon with highs in many areas topping out in the 70’s. Overnight a weak cold front crossed the region returning the area to what would be considered normal for this time of year. Main items of interest this morning the winds for today and then rain chances along and behind the next arctic front on Wednesday.

Pressure gradient is fairly tight this morning and once the sun is up and low level mixing begins expect winds to come up. Will likely see sustained winds of 15-25mph with gust to 30mph late this morning and early this afternoon before the gradient begins to relax this evening. Clear and cold night is on tap for the region with low sin the upper 20’s and lower 30’s.

Surface high pressure moves eastward Tuesday allowing onshore flow to develop and a return of low level moisture into the region along with warmer temperatures. PWS climb toward .8-1.0 inches by late Tuesday ahead of a strong cold front that will be dropping into NW TX. Combination of strong frontal lift and increasing moisture will set the stage for a round of showers/thunderstorms with the front and some post frontal light rain. Incoming arctic dome will be extremely shallow and expect this cold air mass to undercut the near surface moist layer. Frontal timing is still debatable from the early morning Wed over our NW counties to early afternoon around the coast. High temperatures will be prior to the boundary crossing a location with a rapid fall into the 40’s behind the front and then the 30’s.

Temperatures by Wednesday afternoon look to fall to freezing over parts of our northern counties with the threat for light rain turning to light freezing rain or freezing drizzle mainly north of a line from Livingston to Huntsville to College Station to Giddings. At this time precipitation should be light with any icing mainly on bridges and overpasses. Travel to the Austin and Dallas areas on Wednesday will likely be extremely hazardous with a greater threat of freezing rain and sleet producing icy road conditions.

Very cold once again behind the Wednesday front with low temperatures back into the 20’s for most locations Thursday-Saturday mornings. Return flow begins on Saturday and it appears an upper level pattern change will begin allowing the amplified pattern of late to become more zonal helping cut off the supply of cold air from Canada. Should see a warming trend for multiple days into next week.

So how did this past Arctic Outbreak compare with others:

For south Texas it was the coldest temperatures since the outbreak of December 1989 and the first ice/snow since December 2004. Record lows were set at Brownsville on the 4th (29) and McAllen on both the 4th and 5th (28 and 27). Temperatures were below freezing at Hebbronville for 60 hours and 31 hours at Brownsville.

At Austin temperatures were below freezing for 69.5 hours (record 140 hours) and San Antonio 65 hours (record 108 hours). This was the first snowfall for the city of San Antonio since Feb 13/14, 2004. The .9 of an inch of snow at Austin broke the daily snowfall record of .5 of an inch in 1906.

The first 4 days of February have been some of the coldest on record for Houston Galveston and College Station. Each climate site had their second coldest average lows for this period with only 1951 being colder. Galveston recorded 5 straight days with lows at or below freezing including 4 days in the 20’s (the average is 50). BUSH IAH recorded 5 straight mornings below freezing (in the 20’s) and only recorded at high of 31 on Friday the 4th. The 1/8th to 1/4th of an inch of ice accumulation across the area was the most significant icing event since January 1997 when 1.0-1.5 inches of ice accumulated over the region.

[Ed Lizard]

GFS verbatin in Dallas, a few tenth or two of liquid rain, followed by ballpark 2 or 3 inches of snow, and then a hard freeze for over a say, perhaps another snow day for the happy children of the Metroplex.

[Srain]

12Z Canadian is trending toward the 00Z Euro solution...

[David Reimer]

GFS verbatin in Dallas, a few tenth or two of liquid rain, followed by ballpark 2 or 3 inches of snow, and then a hard freeze for over a say, perhaps another snow day for the happy children of the Metroplex.

Considering temperatures that night will fall into the teens, I'm already betting on one if not two days of missed school this week.

[wxmx]

Rollercoaster February, after the freeze, 86F yesterday, and back to freezing lows Thu. Oh joy!

[Srain]

HPC:

...WAVE CROSSING THE GULF STATES DAY 3...

PRELIMINARY PREFERENCE: PENDING 12Z/07 ECMWF

THE NAM IS LESS SUPPRESSED WITH THE TRACK OF THIS SYSTEM THAN THE

00Z/07 ECMWF...WITH THE GFS SLIGHTLY MORE SUPPRESSED. THE GEM

GLOBAL IS CLOSEST TO THE ECMWF...WITH THE UKMET CLOSEST TO THE

NAM. CONSIDERING THE TRENDING OF THE GUIDANCE WITH THIS ENERGETIC

FEATURE...WILL WAIT FOR THE 12Z/07 TO MAKE A CALL HERE.