Texas Winter 2012-2013

[Longhornmaniac8]

What does the King say?

[Cyclenall]

Canadian just jumped ship and joined the GFS party, nada just a little rain for Brownsville!

I'm sure people in this thread will be thrilled to hear this.

Anyone check out the latest progs for the stratosphere? Warming completely breaks down the Arctic vortex, displacing the anomaly near the troposphere unusually so. If these forecasts hold true, we may see the PV get pushed as far south as the US/Canadian border

http://www.cpc.ncep.noaa.gov/products/s ... strat_a_f/

It qualifies as a major sudden stratospheric warming event.

I have 2 questions: 1. How often does a PV get near the boarder like that (once every x years) and 2. What would that look like on surface pressure maps? A very powerful high or something at a different level of the atmosphere?

What does the King say?

Not yet. The King is currently running .

[Ntxw]

I have 2 questions: 1. How often does a PV get near the boarder like that (once every x years) and 2. What would that look like on surface pressure maps? A very powerful high or something at a different level of the atmosphere?

Not sure the exact statistics, maybe once every 5 years or so. The great Lakes region sees sub 492 thickness, and a large -30c 850s or greater area covers the southern Canadian provinces and northern US. Early Feb 2007 was the last time I can recall such an event, also coupled with a major SSW event. High pressure doesn't generate true cold, the PV does. They are mostly used to transport the cold on the backside of the PV, the stronger the high, the stronger the push of cold south but the true cold stays under the vortex.

Something like this

http://www.meteo.psu.edu/~fxg1/NARR/200 ... hp#picture

[wxman22]

Just checked the 0z Euro and it still looks nice, atleast for the southern half of the state.

[Ntxw]

Euro did not join the GFS *sigh of relief*, not as expansive as the 12z but still has a pretty good area of wintry precip in Central/West/Southeast Texas

Edit: Going by roughly 540 thickness this would be a sleet storm for a line east/south of Austin-Waco-Tyler

[LaBreeze]

Just checked the 0z Euro and it still looks nice, atleast for the southern half of the state.

"Looks nice" = meaning ???

[ravyrn]

06z GFS has some interesting frames at the end of its run in 384hr lalaland lol. -30C plunging down the plains.

[Portastorm]

It appears the long arm of the Portastorm Weather Center extends beyond Storm 2K! See relevant snippet below from this morning's AFD out of EWX:

PERSISTENT COOL AIR ADVECTION AND MOSTLY CLOUDY SKIES SHOULD MAKE
TUESDAY AND WEDNESDAY CHILLY AND DREARY...AS UPPER TROUGHING
CONTINUES TO BE HUNG UP TO THE WEST OVER THE SOUTHERN ROCKIES. THE
EJECTION OF THIS TROUGH COULD OFFER A BRIEF WINTER WEATHER EVENT
WHEN IT FINALLY EJECTS EAST. MODEL SOLUTIONS REMAIN QUITE VARIED
AND MAKE ANY WINTER WEATHER PROJECTION A GAMBLE...GIVEN THAT THE
AVAILABLE MOISTURE NEEDED TO GENERATE PRECIP WILL LIKELY BE
LIMITED AND SHALLOW. MOST OF THE MODEL DATA SHOWS THE EJECTING
TROUGH TO BE WEAK AND NOT CAPABLE OF PRODUCING SIGNIFICANT WINTER
PRECIP...SO WILL KEEP A DRY FORECAST IN PLACE FOR WEDNESDAY INTO
THURSDAY...SAVE FOR A FEW RAIN SHOWERS OVER THE COASTAL PRAIRIES.

-------------------------
All kidding aside, PWC gives out props this morning to the forecaster who wrote this AFD. Good work, covering all angles.

[Snowman67]

06z GFS has some interesting frames at the end of its run in 384hr lalaland lol. -30C plunging down the plains.

Think you might mean -3C if you are referring to what is showing in Kansas on the map. The -3C is right next to the 0C on the map making it look like -30C. However, if you look closely the -3C is in "blue" and the 0C in "purple". There is however some -27C 850mb temps up in Montana and a portion of the Dakotas on that map.

[Portastorm]

Speaking of good forecast discussions ... the preliminary 3-7 day discussion out of the Hydrometeorological Prediction Center (HPC) is very insightful:


EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
142 AM EST SUN DEC 30 2012

VALID 12Z WED JAN 02 2013 - 12Z SUN JAN 06 2013

...BELOW NORMAL TEMPERATURES EXPECTED ACROSS MUCH OF THE UNITED
STATES...

BY DAY 4...THE ENSEMBLE SPREAD BY ITSELF WOULD SUGGEST ANYTHING
GOES ALONG THE WEST COAST AS ENERGY FROM THE EAST PAC MIGRATES
EASTWARD INTO NORTH AMERICA. HOWEVER...THE FORECAST PHILOSOPHY
REALLY DOES NOT CHANGE MUCH...WITH THE RIDGE REBUILDING ALONG 120W
ON DAY 7. THE REASON FOR THE LARGE SPREAD IN THE DAY4 TIME FRAME
REMAINS TIED TO THE INDIVIDUAL MODELS AND THEIR RUN-TO-RUN
VARIABILITY IN HANDLING THE SPLIT-FLOW PATTERN AND EMBEDDED ENERGY
MOVING AROUND THE RIDGE THROUGH SOUTHWEST CANADA AND THE DESERT
SOUTHWEST. AND MORE IMPORTANTLY...HOW WILL THE DAY4-5 SYSTEM
INTERACT WITH THE UPPER-LEVEL RIDGE AND WHERE WILL THAT SYSTEM
REORGANIZE DOWNSTREAM.

THE MEDIUM RANGE TEMPERATURE/PRECIPITATION PROGS SUGGEST VERY
LITTLE CHANGE AND NOT MUCH IN THE WAY OF APPRECIABLE PRECIPITATION
POTENTIAL EXCEPT ALONG THE GULF COAST...GREAT LAKES AND NEW
ENGLAND. ASIDE FROM SOME DOWNSLOPING (ADIABATIC WARMING) ACROSS
AND IMMEDIATELY DOWNSTREAM OF THE NORTHERN ROCKIES...MT/WY/CO
MAINLY...THE SENSIBLE WEATHER PARAMETERS BENEATH THE UPPER RIDGE
APPEAR TO BE 'UNPHASED' BY THE DAY3-4 PACIFIC SYSTEM AND ITS
ATTEMPT TO TAKE THE NORTHERN ROUTE THROUGH ALBERTA AND
SASKATCHEWAN BEFORE ENTERING THE CONFLUENT AND DRY NORTHWEST FLOW
ANCHORED OVER MANITOBA AND THE UPPER MIDWEST. TEMPERATURES SHOULD
REMAIN WELL BELOW NORMAL IN THE GREAT BASIN AND DESERT SOUTHWEST/4
CORNERS AREA.

THE BASELINE GUIDANCE USED IN THIS MORNING PACKAGE (29/12Z CYCLE)
DID HAVE SOME INTERESTING OUTCOMES. THE CANADIAN SOLUTION APPEARED
TO TAKE NEARLY ALL THE ENERGY BUTTING UP AGAINST THE UPPER-LEVEL
RIDGE NORTHWARD...AND INTO BC. THIS HAS BEEN THE BIGGEST
DEPARTURE. ITS 'NEW' NORTHWARD RATHER THAN THE AGGRESSIVE SOUTHERN
TRACK THROUGH MUCH OF CALIFORNIA WAS TO BE EXPECTED...GIVEN IT WAS
IN SERIOUS TROUBLE LAST NIGHT (ITS VERY SLOW 28/12Z CYCLE
SOLUTION) IN THE GULF OF ALASKA. THE RECENT RUNS OF THE ECMWF
STILL ATTEMPT THE MIGRATION OF A CUTOFF LOW ALONG THE CALIFORNIA
COAST...BUT THE 29/12Z OFFERED A CURIOUSLY IMPROBABLE TRACK
THROUGH THE CENTER POINT (OR HEART OF THE RIDGE AXIS) INVOF 40N
LATITUDE. ITS THE GFS THAT CONTINUES TO BE THE FAST OUTLIER.
HOWEVER...EARLY DAY 4 IT DOES START OUT LIKE THE ECMWF
TRACK...THEN TURNS THE SYSTEM NORTHEASTWARD. CURIOUSLY...BY DAY
6...IT (THE GFS) SIDES WITH THE ECMWF AND THE NEW CUTOFF SOLUTION
ALONG 140W AND GENERALLY FITS WITHIN REASON ALONGSIDE THE ECMWF
OVER THE ALEUTIANS AND GULF OF ALASKA. THAT SAID...

THE KEY FOR ANY APPRECIABLE CHANGE IN THE MEDIUM RANGE ACROSS THE
CONUS...IS APPARENTLY 'ANCHORED' DOWNSTREAM IN EASTERN CANADA. AND
FROM WHAT I CAN DECIPHER THIS MORNING...THERE IS NOT GOING TO BE
MUCH CHANGE THROUGH DAY 7 EAST OF THE MISSISSIPPI...INCLUDING THE
GREAT LAKES... NORTHEAST... MIDWEST... OHIO VALLEY...CENTRAL
APPALACHIANS AND MID ATLANTIC STATES. IN FACT...HUDSON BAY AND ITS
BROAD VORTEX IS QUASI-STATIONARY THROUGH THE PERIOD...WITH A
DEEP/COLD TROUGH ANCHORED IN PLACE ACROSS THE NORTHEAST AND GREAT
LAKES AND A CONFLUENT TRANSITION ZONE FOR THE COLD CANADIAN
AIRMASS RUNNING WNW TO ESE FROM ROUGHLY WESTERN IOWA/EASTERN
NEBRASKA TO THE OUTER BANKS AS SPLIT-FLOW ENERGY UPSTREAM EXITS
THE ROCKIES.

RAINFALL IN THE MEDIUM RANGE PERIOD SHOULD BE CONFINED TO THE
ZONAL SOUTHERN STREAM...WITH THE GULF COAST STATES RECEIVING THE
BULK OF THE MOISTURE AND BRIEF OVER RUNNING EPISODES IN THE
SOUTHERN HIGH PLAINS/RIO GRANDE VALLEY. THE HIGHER PROBABILITIES
OF MEASURABLE SNOWFALL SHOULD SET UP IN THE DRIER...NORTHERN
STREAM AND MAINLY IMPACT THE GREAT LAKES REGION AND
NORTHEAST...UPPER OHIO VALLEY AND NORTHERN MID ATLANTIC. AS
MENTIONED ABOVE...THE GREATEST UNCERTAINTY FOR P-TYPE...IS WITHIN
THE OSCILLATING TRANSITION ZONE BETWEEN 35-40N
LATITUDE...GENERALLY EAST OF 100W LONGITUDE IN THE EXPECTED FLOW
REGIME ACROSS NORTH AMERICA THROUGH DAY 7.

VOJTESAK

[wxman57]

00Z Euro had snow from El Paso to very near San Antonio/Austin on Thursday. Just trace amounts around SAT/AUS. Some trace amounts about 50 miles north of Houston.

[Snowman67]

00Z Euro had snow from El Paso to very near San Antonio/Austin on Thursday. Just trace amounts around SAT/AUS. Some trace amounts about 50 miles north of Houston.

Sounds like perfect biking weather...

[Snowman67]

Hou/Galv keeping all options open...

PREV DISCUSSION... /ISSUED 421 AM CST SUN DEC 30 2012/

DISCUSSION...
PACIFIC MOISTURE CONTINUES TO STREAM INTO THE AREA ON THE WSW
FLOW ALOFT. TROUGH DEEPENING ALONG THE CALIFORNIA COAST WHICH
WILL CONTINUE TO TAP THE PACIFIC MOISTURE AND LOWER THE PRESSURES
OVER NEW MEXICO. AS THESE PRESSURES FALL THE NORTHEAST FLOW OVER
THE AREA WILL VEER TO THE EAST AND SOUTHEAST TODAY AND TONIGHT
INCREASING THE LOW LEVEL MOISTURE. WARM FRONT SLOWS AS IT NEAR THE
COAST LATE TONIGHT AND SHOULD MAKE FOR A CLOUDY/FOGGY MORNING
MONDAY. S/W LIFTS NORTHEAST INTO THE STATE AND A PREFRONTAL TROUGH
MOVES INTO SETX MONDAY STARTING UP A WET PERIOD FOR THE AREA. THE
REGION STILL HAS A FAVORABLE JET OVERHEAD WITH ABUNDANT MOISTURE
BUT INSTABILITY WILL BE MARGINAL FOR THUNDERSTORMS...MU CAPE OF
200-500 J/KG WILL BE LIMITED TO THE AREAS MAINLY SOUTHWEST OF A
COLLEGE STATION TO LIVINGSTON LINE THOUGH ALONG THE RICHEST
MOISTURE ADVECTION AXIS. EXPECT THAT WE WILL START OUT WITH
ISENTROPIC LIFT AND LIGHT RAIN AND THEN TRANSITION TO BANDS OF
SHOWERS AND EVENTUALLY THUNDERSTORMS BY LATE MORNING/AFTERNOON.
SOME THREAT OF TRAINING OF STORMS MONDAY AFTERNOON THROUGH TUESDAY
MORNING AS THE FRONT CATCHES UP TO THE PREFRONTAL TROUGH AND MOVES
OUT INTO THE COASTAL WATERS TUESDAY BETWEEN 6 AM AND NOON. THE
FRONT SLOWS AND STALLS IN THE NORTHWEST GULF REMAINING ACTIVE WITH
UPGLIDE AND CLOUDS SPREADING NORTH OVER SETX AND SHOWERS OVER THE
COASTAL WATERS TUESDAY AND WEDNESDAY. SETX WILL BE COOL AND BREEZY
AT TIMES IN THE WAKE OF THE FRONT WITH A REINFORCING SHOT OF COLD
AIR WEDNESDAY. WILL BE LOWERING TEMPERATURES FOR WEDNESDAY. AGAIN
THE MODELS (GFS/ECMWF) DIFFER FOR THIS PERIOD WITH THE GFS
CONSISTENTLY THE DRIER WITH THE CLOUDS FINALLY SHIFTING SOUTH
WHILE THE ECMWF REMAINS CONSISTENT WITH ITSELF IN BRINGING UP A
LAGGING S/W THAT SPREADS PRECIP NORTH IN THE COLD AIR OVER SETX
LATE WEDNESDAY/THURSDAY. ECMWF SOUNDINGS STILL SUPPORT SNOW OR
MIXED RAIN/SNOW ON THURSDAY MORNING IN THE NORTHWEST. THE FLOW
OVER THE WESTERN U.S. IS CONVOLUTED AND COMPLEX AND CONFIDENCE IN
EITHER SOLUTION REMAINS LOW. WILL CONTINUE TO CARRY POPS FOR RAIN
WED/THU FOR NOW DUE TO THE UNCERTAINTY. BY FRIDAY THE REGION
SHOULD BE DRY OR DRYING OUT THOUGH THE SKY FORECAST REMAINS MIXED.

[iorange55]

12z NAM looks to be picking up on some moisture down in southwest Texas at the end of its run. It's the long range NAM, though.

[GRAYSONCO.WX]

12z NAM looks to be picking up on some moisture down in southwest Texas at the end of its run. It's the long range NAM, though.

Indeed, it does!

[SaskatchewanScreamer]

You evil lot are enjoying this too much!

I'll turn ALL my fans on and will send the polar bears and wolves express to y'all!!!

[Tireman4]

:lol: You evil lot are enjoying this too much!

I'll turn ALL my fans on and will send the polar bears and wolves express to y'all!!!

Uh oh. You do not want librarians becoming unhinged...LOL

[SaskatchewanScreamer]

You might just want to start burning those treasured books of yours Tireman.

[Portastorm]

:lol: You evil lot are enjoying this too much!

I'll turn ALL my fans on and will send the polar bears and wolves express to y'all!!!

Promises, promises ... I'm still waiting for said fans to really turn on.

[SaskatchewanScreamer]

and best start learning how to build an igloo cause your delicate pipes won't survive.