Texas winter wx thread#5 - big changes on the way eventually

[teal61]

Take a look at the Great Falls Montana Afd, seems as though the artic air is about to begin entering the US.



AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
450 AM MST WED JAN 10 2007

.DISCUSSION...

TODAY THROUGH FRIDAY...THE ARCTIC SYSTEM IS APPROACHING QUICKLY
THIS MORNING. THE SURFACE LOW PRESSURE AREA IS OVER SOUTHERN
ALBERTA AT THIS TIME AND IT CONTINUES TO MOVE SOUTHEAST INTO THE
FORECAST AREA. THE PACIFIC COLD FRONT IS MOVING THROUGH WESTERN
MONTANA...WHILE THE ARCTIC COLD FRONT IS DRAPED NORTHWEST INTO
SOUTHERN BRITISH COLUMBIA. THIS SYSTEM WILL MOVE SOUTHEAST THROUGH
THE FORECAST AREA DURING THE DAY TODAY FOR GENERALLY FALLING
TEMPERATURES THROUGHOUT THE DAY. STRONG WESTERLY WINDS WILL
CONTINUE THROUGH THE MORNING OVER THE PLAINS OF NORTH CENTRAL
MONTANA UNTIL THE SURFACE LOW MOVES THROUGH...SO WILL CONTINUE THE
HIGH WIND WARNING THROUGH 11 AM MST. SNOW WILL CONTINUE OVER THE
WESTERN MOUNTAINS THROUGH THE DAY...AND AREAS OF LIGHT SNOW WILL
DEVELOP OVER THE PLAINS TODAY AND TONIGHT AS THE SYSTEM
PROGRESSES SOUTHEAST. AREAS OF BLOWING SNOW WILL BE POSSIBLE
THROUGH TONIGHT...AS NORTHERLY WINDS WILL REMAIN AROUND 15 TO 25
MPH BEHIND THE ARCTIC FRONT. WITH TEMPERATURES CONTINUING TO FALL
OVERNIGHT INTO THURSDAY WITH THESE WINDS...HAVE ALSO ISSUED A WIND
CHILL ADVISORY FOR ALL OF NORTH CENTRAL AND CENTRAL MONTANA FROM 8
PM MST THIS EVENING THROUGH 11 AM MST THURSDAY. WIND CHILL
TEMPERATURES WILL FALL INTO THE 20 TO 40 DEGREE BELOW ZERO RANGE.
SNOW WILL ALSO DEVELOP OVER SOUTHWEST MONTANA THROUGHOUT THE DAY
AS THE PACIFIC FRONT MOVES THROUGH THAT AREA. THIS SNOW ACROSS
SOUTHWEST MONTANA WILL PERSIST OVERNIGHT AND INTO THURSDAY
MORNING. HAVE THEREFORE ISSUED A SNOW ADVISORY FOR MADISON AND
GALLATIN COUNTIES FROM 11 AM MST TODAY THROUGH 11 AM MST THURSDAY.
AREAS OF BLOWING SNOW ARE POSSIBLE THERE TODAY...BUT WINDS WILL
DECREASE TONIGHT. THIS SYSTEM WILL EXIT THE AREA THURSDAY NIGHT
INTO FRIDAY...AND PARTIALLY CLEARING SKIES WILL CAUSE TEMPERATURES
TO FALL INTO THE 5 BELOW TO 20 BELOW RANGE FOR THURSDAY NIGHT.
COULSTON

FRIDAY NIGHT THROUGH MONDAY NIGHT...MODELS SUGGEST THAT THE UPPER
LEVEL LOW OVER THE SOUTHWESTERN CONUS WILL GRADUALLY WEAKEN AND
MOVE EAST. ASSOCIATED UPPER TROUGH OVER MONTANA WILL ALSO MOVE
OFF... LEAVING MY FORECAST AREA BENEATH A WEAK NORTHWEST FLOW
ALOFT THROUGH THE WEEKEND. BY EARLY NEXT WEEK THIS WEAK FLOW WILL
TRANSITION TO A STRONGER NORTHERLY FLOW. ANOTHER SURGE OF CANADIAN
AIR WILL PUSH INTO EASTERN MONTANAN SATURDAY NIGHT OR SUNDAY. A
BACKDOOR FRONT SETS UP ACROSS MY CENTRAL ZONES AND COMBINES WITH A
WEAK UPPER LEVEL WAVE FOR AT LEAST A SLIGHT CHANCE OF SNOW ACROSS
MY ENTIRE FORECAST AREA. UPPER WAVE EXITS THE AREA BY LATE MONDAY
ALLOWING A WEAK SURFACE TROUGH TO DEVELOP IN ALBERTA. THE AIRMASS
IS EXPECTED TO BE MAINLY DRY DURING THIS TIME FRAME AND
TEMPERATURES WILL WARM UP A BIT...BUT ARE STILL EXPECTED TO BE
BELOW SEASONAL NORMALS. MPJ

TUESDAY AND WEDNESDAY...LONG RANGE MODELS CONTINUE TO DEPICT A
STRONG RIDGE OF HIGH PRESSURE JUST OFF THE PACIFIC NORTHWEST
COAST. A NORTHERLY FLOW ALOFT OVER MONTANA WITH A DISTURBANCE
FLOWING THROUGH BY MID WEEK WILL PROVIDE A CHANCE FOR SNOW SHOWERS
IN THE MOUNTAINS AND ON THE CENTRAL PLAINS. TEMPERATURES ARE
PROJECTED TO BE SLIGHTLY BELOW NORMAL FOR THE CENTRAL PLAINS.
SAUCIER

&&

.AVIATION...
UPDATED 1150Z.
DEEP ALBERTA CLIPPER SURFACE LOW WILL MOVE ACROSS EASTERN MONTANA
TODAY. CANADIAN COLD FRONT MOVES INTO NORTH CENTRAL MONTANA BY
15Z...REACHING KGTF-KHVR LINE BY 18Z...AND CONTINUING SOUTH AND EAST
TODAY THROUGH TONIGHT. STRONG AND GUSTY SOUTHWEST TO WEST WINDS WILL
BECOME NORTH-NORTHWESTERLY BEHIND THE FRONT. LOW AND MID LEVEL
CLOUDS WILL ALSO MOVE INTO THE REGION WITH AREAS OF SNOW DEVELOPING
...ESPECIALLY IN FAVORED UPSLOPE LOCATIONS. MPJ

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF 34 -8 -1 -12 / 20 40 30 10
CTB 30 -10 -4 -17 / 30 40 20 10
HLN 34 0 2 -9 / 50 40 30 10
BZN 36 2 3 -9 / 80 80 50 30
WEY 29 1 8 -12 / 70 80 60 40
DLN 35 4 6 -9 / 70 50 30 20
HVR 35 -9 -3 -18 / 30 30 20 0
LWT 37 -5 0 -10 / 20 40 30 20

[Jagno]

I know this isn't a TX forecast but it seems to be too close to overlook since we are so close. This is for Lake Charles, Louisiana. Notice the rain chances all the way through Wednesday. If these temps are too warm as mentioned several times and we do get this precip then we are headed towards trouble. Cajuns don't do winter well. LOL

This is copied from http://www.weather.com


10-Day Forecast NEW: Faster Radar Maps & No Ads


High /
Low (°F) Precip. %
Today
Jan 10 Sunny 61°/46° 0 %
Thu
Jan 11 Mostly Cloudy 68°/60° 10 %
Fri
Jan 12 Isolated T-Storms 74°/65° 30 %
Sat
Jan 13 Scattered T-Storms 75°/65° 40 %
Sun
Jan 14 T-Showers 67°/39° 30 %
Mon
Jan 15 Few Showers 51°/36° 30 %
Tue
Jan 16 Showers 48°/35° 60 %
Wed
Jan 17 Mostly Sunny 53°/36° 10 %
Thu
Jan 18 Mostly Cloudy 55°/36° 0 %
Fri
Jan 19 Showers 51°/38° 60 %

[TexasStooge]

The freezing rain is once again taken out of the forecast from DFW, which sems to be good news to those who are going to church on Sunday. Of course, as the day draws near, we may in fact get some wintry precip.

Select Cities Forecast

SHERMAN
Sunday: 34°F | 24°F
_____________________________________________________________

WICHITA FALLS
Sunday: 32°F | 18°F
_____________________________________________________________

AMARILLO
Saturday: 33°F | 15°F
Sunday: 26°F | 11°F

[Portastorm]

Interesting AFD from Montana.

My recollection is that these arctic fronts take 3 days to reach central Texas, when being pushed south by a health high ... which is what we will have. I'm telling you folks, I'm still saying frontal passage through most of Texas on Saturday. Front reaches the coast late Saturday night or early Sunday.

[double D]

What is up the Austin/San Antonio NWS changing the forecast on every single gfs run? Do they have interns in charge right now or what? Instead of changing every forecast up and down, why don't they communicate with other NWS offices before drastically changing their forecast?

[double D]

Interesting AFD from Montana.

My recollection is that these arctic fronts take 3 days to reach central Texas, when being pushed south by a health high ... which is what we will have. I'm telling you folks, I'm still saying frontal passage through most of Texas on Saturday. Front reaches the coast late Saturday night or early Sunday.

Nice find Portastrom...By the way what is the latest from JB? Is he still bullish on the cold air and has he changed his tune about possible winter precip in Texas?

[teal61]

A quick glance at the 6z GFS seem to show a little more moisture than the previous few runs around or just south of SE Texas for the mid week period. It will be interesting to see if the 12z run continues this trend.

[Portastorm]

Interesting AFD from Montana.

My recollection is that these arctic fronts take 3 days to reach central Texas, when being pushed south by a health high ... which is what we will have. I'm telling you folks, I'm still saying frontal passage through most of Texas on Saturday. Front reaches the coast late Saturday night or early Sunday.

Nice find Portastrom...By the way what is the latest from JB? Is he still bullish on the cold air and has he changed his tune about possible winter precip in Texas?

Well, it was actually teal 61 who found that ... not me.

JB is still very bullish on the cold air outbreak and is suggesting some major temp busts on Saturday in the southern Plains.

On the precip front ... no mention in the last few days. I'm kinda curious myself what his take is on that.

[cctxhurricanewatcher]

What is up the Austin/San Antonio NWS changing the forecast on every single gfs run? Do they have interns in charge right now or what? Instead of changing every forecast up and down, why don't they communicate with other NWS offices before drastically changing their forecast?

What say you Portastorm?

[aggiecutter]

The 850 anomalies on this mornings' Ensemble are impressive as I have seen in years as far as prolonged cold is concerned. However, the SE ridge is not going to give up the ghost easily and could hold up frontal passage until late Sunday night in the SE half of the state.

Morning Ensembles:
http://www.cdc.noaa.gov/map/images/ens/ ... times.html

[Portastorm]

What is up the Austin/San Antonio NWS changing the forecast on every single gfs run? Do they have interns in charge right now or what? Instead of changing every forecast up and down, why don't they communicate with other NWS offices before drastically changing their forecast?

What say you Portastorm?

Ha,ha! Don't get me started.

I have been asking this very same question for years. It seems reasonable to expect that NWS forecasters would share notes and collaborate with their colleagues when necessary. Sometimes they don't have time and I understand that. But if you read these forecast discussions for any period of time, you see which offices talk to other offices and which ones operate in a silo.

[gboudx]

Well, it was actually teal 61 who found that ... not me.

JB is still very bullish on the cold air outbreak and is suggesting some major temp busts on Saturday in the southern Plains.

On the precip front ... no mention in the last few days. I'm kinda curious myself what his take is on that.

I don't subscribe to accuweather professional, but knowing JB from the posts and direct comments you guys post here, if there was precip chances, seems like he'd be all over it. So, I take this "no mention" as meaning there isn't much to discuss. Thoughts?

[aggiecutter]

The most impressive graphic on this mornings' Ensembles is the thicknesses. I've never seen sustained thicknesses that low in the southern plains for this long a period of time.

ENSEMBLE Thickness 1000-500mb:
http://www.cdc.noaa.gov/map/images/ens/ ... times.html

[cctxhurricanewatcher]

The 850 anomalies on this mornings' Ensemble are impressive as I have seen in years as far as prolonged cold is concerned. However, the SE ridge is not going to give up the ghost easily and could hold up frontal passage until late Sunday night in the SE half of the state.

Morning Ensembles:
http://www.cdc.noaa.gov/map/images/ens/ ... times.html

Am I reading this right? The air mass makes it all the way down to southern Mexico????

[cctxhurricanewatcher]

The most impressive graphic on this mornings' Ensembles is the thicknesses. I've never seen sustained thicknesses that low in the southern plains for this long a period of time.

ENSEMBLE Thickness 1000-500mb:
http://www.cdc.noaa.gov/map/images/ens/ ... times.html

When was the last time you saw it like this?

[Kennethb]

You generally can't rely on one arctic plunge to get the cold weather and precip. The first blast will set the stage. It is the one's afterwards that reinforce and establish the cold air. Eventually shortwaves from the north and or disturbances in the southern stream will become involved. Patience is needed. Wintry precip will appear. Late January and early February are the best time for wintry precip in the mid and deep south

[aggiecutter]

Kennethb, you are the winner. It is about the pattern, not a one time cold shot. There will be repetitive cold shots over the next few weeks. It's just a matter of time before a disturbance comes a long, or a strong area of low pressure forms in the Gulf.

[Portastorm]

Just took a look at the 12z NAM run. Still hangs the arctic boundary up in far north Texas and the panhandle out to 84 hrs. Not sure why, other than the model still looks bullish on a surface low developing in New Mexico. Lots of precip by Sunday though in most of the state.

I'd post a link but I saw mine through the Accuwx pro site and the NCEP site still has updated with this run. Sorry.

[gboudx]

Update from DFW NWS. I also notice that freezing drizzle/rain has been added to my forecast on Sunday.

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1000 AM CST WED JAN 10 2007

.UPDATE...
HAVE UPDATED THE ZONES/GRIDS TO REFLECT HIGHER WIND SPEEDS THIS
AFTERNOON AND ALSO TO LOWER DEWPOINTS. A GOOD WARM UP IS EXPECTED BY
THIS AFTERNOON AND TEMPS AND OTHER PARAMETERS LOOK FINE.

OTHERWISE...12Z NAM HAS GIVEN US SOME CONFIDENCE IN THE FORECAST
THIS WEEKEND WITH THE ARCTIC FRONT. NAM SHOWS FRONT MOVING INTO THE
AREA EARLY SATURDAY WHICH IS WHAT THE GUT FEELING HAS BEEN...BUT
WITH NO GUIDANCE SHOWING THIS YESTERDAY WE WERE HEDGING TOWARD THIS
SOLUTION. WITH THE INCREASED CONFIDENCE NOW...HAVE DECIDED TO LOWER
TEMPS AND ADJUST WINDS FOR THE FASTER NAM FROPA TIMING. THIS
RESULTS IN A GREATER AREA OF FREEZING RAIN SATURDAY NIGHT AND
SUNDAY...WHICH ROUGHLY COVERS THE NW HALF OF THE AREA. THE NAM DOES
SHOW A DEEPER AND SLOWER UPPER TROUGH PROGRESSION THAN THE OTHER
MODELS...BUT WILL NOT MESS WITH POPS SUN-MON UNTIL ALL THE 12Z
GUIDANCE IS IN TO SEE IF THERE IS ANY AGREEMENT ON THIS.

[cctxhurricanewatcher]

JB headline on his 11 am (EST) update.

"DEEP SOUTH IN FOR MULTIPLE COLD SHOTS NEXT MONTH TO TWO MONTHS FREEZE THREATS POSSIBLE WITH CITRUS AREAS. "