Texas Winter 2010-2011

[txagwxman]

:uarrow:

What are we looking at here, sir?

JMA model.

[Ntxw]

Breaking News: In turn of recent events, subscription prices to the PWC has gone down. Much like in Egypt, a mob of weather enthusiasts has been seen gathering outside headquarters in an undisclosed Austin, TX location. Director of the PWC has been spotted holding weather charts leaving the scene to a safe underground location until 0z runs comes in for the rescue.

[txagwxman]

I will probably change my mind on Sunday...have a good weekend.

[downsouthman1]

I will probably change my mind on Sunday...have a good weekend.

I would like to think you said this because you just saw something in a model, but I know that it's just the small piece of hope within.

[Tireman4]

Breaking News: In turn of recent events, subscription prices to the PWC has gone down. Much like in Egypt, a mob of weather enthusiasts has been seen gathering outside headquarters in an undisclosed Austin, TX location. Director of the PWC has been spotted holding weather charts leaving the scene to a safe underground location until 0z runs comes in for the rescue.

Wait, where is the party? They were doing the chicken dance yesterday. I thought it was at the PWC and now, I come the parking lot and it is crowded with
folks clamoring for a sight of the director....

[wxman57]

My favorite model, the Tahiti model, indicates warm, sunny weather all next week, as you can see below:

[Tireman4]

My favorite model, the Tahiti model, indicates warm, sunny weather all next week.
http://www.destination360.com/australia ... eaches.jpg

Hey wait,, are you in one of those huts doing forecasts there?

[mrgolf]

I have a question for either txagwxman or wxman57,. Is the main reason the storm is tracking so far west because of the lack of blocking in greenland,and if thats not it please fill me in on why please. Im optimistic we will get a -ao and nao fairly soon again.That would help us out more i do believe,especially for southern plains and midsouth.

[BigB0882]

Count me in as another who is praying for a -NAO soon. If we can get negative within the next 2-3 weeks then we might have a last minute shot at winter fun down this way. Canada looks locked and loaded but we need the negative to get it this way. The southern jet stream also looks to remain active.

[srainhoutx]

HPC Final Update:

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
136 PM EST FRI JAN 28 2011

VALID 12Z MON JAN 31 2011 - 12Z FRI FEB 04 2011



...MAJOR WINTER STORM SETTING UP NEXT WEEK FROM THE ROCKIES TO THE
NORTHEAST...


MEDIUM RANGE GUIDANCE IS AGREEABLE WITH THE LARGE SCALE SCENARIO
OF AN ELONGATED MEAN TROF EXTENDING FROM NERN CANADA SWWD INTO THE
SWRN CONUS... LIKELY WITH SOME SEPARATION BETWEEN SRN CANADA/NRN
TIER CONUS FLOW AND WRN/SRN CONUS FLOW. THIS TROF WILL BE
SUPPORTED BY A MEAN RIDGE THAT SHOULD PERSIST OVER THE ERN PAC/WRN
CANADA ALBEIT WITH SOME CHANGE IN SHAPE OVER TIME. WHILE A GOOD
CONSENSUS EXISTS WITH THE LARGE SCALE MEAN EVOLUTION... THERE IS
LOWER THAN AVERAGE CONFIDENCE IN DETAILS DUE TO THE SPLIT FLOW
NATURE OF THE NOAM PATTERN AND ADDITIONAL UNCERTAINTIES PRESENTED
BY ERN PAC ENERGY THAT MAY TRY TO PASS THRU THE MEAN RIDGE BY
MID-LATE WEEK.

THE MOST PROMINENT SFC SYSTEM FOR WHICH SHRTWV UNCERTAINTIES COME
INTO PLAY IS FCST TO TRACK NEWD FROM THE SRN PLAINS TUE ONWARD.
TO VARYING DEGREES THE 00Z GFS AND ECMWF HAVE MADE MEANINGFUL NWWD
ADJUSTMENTS FROM FAIRLY SUPPRESSED TRACKS IN MULTIPLE PREVIOUS
RUNS. THE ECMWF TREND IS MORE EXTREME AS ITS PREVIOUS TWO RUNS
WERE ON THE SERN SIDE OF THE ENVELOPE AND THE NEW 00Z RUN IS NOW
ON THE NWRN SIDE OF GUIDANCE. THE CANADIAN IS A FAST EXTREME TO
BRING SWRN CONUS ENERGY INTO THE PLAINS AND IS ALSO IN THE NWRN
PART OF THE SPREAD... WHILE THE UKMET TRACK IS NOT QUITE AS FAR
NWWD AS ITS PREVIOUS RUN. OVERALL PREFER A GEFS MEAN/12Z ECMWF
ENSEMBLE MEAN SOLN THAT FALLS IN THE MIDDLE OF LATEST AND RECENT
GUIDANCE GIVEN THE SENSITIVITY OF SHRTWV DETAILS AND SIGNIFICANT
RUN TO RUN CONTINUITY CHANGES.

BEHIND THIS SYSTEM... BY WED NIGHT-FRI THERE IS CONSIDERABLE
SPREAD REGARDING ENERGY THAT MAY TRY TO PASS THRU THE ERN PAC MEAN
RIDGE. THE 00Z ECMWF AND SLOWER 00Z GFS BOTH SEEM A LITTLE STRONG
SO THE ENSEMBLE MEAN BLEND USED FOR THE PLAINS/ERN CONUS SYSTEM
PROVIDES A MORE TOLERABLE SOLN AT THIS TIME. THE GEFS MEAN IS A
LITTLE EXTREME WITH ITS SLOWER TIMING/WWD ELONGATION OF THE TROF
SETTLING OVER THE SWRN CONUS SO INCLUSION OF THE ECMWF MEAN TONES
DOWN THIS ASPECT OF THE FCST.

WHILE DAYS 5-7 WED-FRI FOLLOW A BLEND OF THE GEFS/12Z ECMWF
MEANS... MISSING DATA DUE TO EARLIER COMMS ISSUES PRECLUDED USE OF
THE ECMWF MEAN FOR DAYS 3-4. THUS THE EARLIER PART OF THE FCST
STARTED WITH A BLEND OF GFS/ECMWF/GEFS MEAN SOLNS TO ARRIVE AT AN
ACCEPTABLE COMPROMISE.

UPDATED MORNING PRELIMS USE A MULTIMODEL BLEND OF 00Z
GFS/ECMWF/CMC/UKMET/GFS ENS MEAN. THE RESULT IS NEARLY IDENTICAL
TO THE EARLIER USED SOLUTION.

12Z MODEL GUIDANCE FOLLOWS CONTINUITY AND A COMPOSITE OF THE RUNS
WOULD CONTINUE TO YIELD THE BLENDED SOLUTION OF HPC. NO CHANGES
FOR AFTERNOON FINALS.

AS SHORTWAVE ENERGY MOVES INTO THE FOUR CORNERS REGION EARLY
TUESDAY AND ARCTIC HIGH PRESSURE PLUNGES DEEP INTO THE PLAINS WITH
GREATER THAN 20 DEGREE NEGATIVE TEMPERATURE ANOMALIES. THIS WILL
BRING STRONG UPSLOPE FLOW INTO THE CO ROCKIES FRONT RANGE WITH
MDT/HVY SNOWFALL TO THE SRN ROCKIES SPREADING EWD INTO THE CENTRAL
PLAINS. MID LEVEL ENERGY SHEARS OUT EWD AND A MDT SFC LOW DEVELOPS
OVER ERN TX BY TUESDAY. THIS LOW MOVES NEWD INTO KY/TN WED AND
REFORMS OFF THE MID ATLC CAPES AND RAPIDLY MOVES NEWD OFF NOVA
SCOTIA BY THURSDAY. MDT TO HVY RAINFALL POTENTIAL SOUTH OF THE LOW
PRESSURE TRACK WITH SNOW ACROSS THE CENTRAL PLAINS AND MAINLY
NORTH OF THE OH RIVER AND MASON DIXON LINE INTO NEW ENG. HEAVY
SNOW THREAT INDICATED BY OPERATIONAL MODELS QPF OUTPUT/ANALOGS AND
FAVORABLE MID AND UPPER LEVEL JET STRUCTURE WITH ICING THREAT
ALONG THE CHANGE OVER AND THEN THE DAMMED IN AREA IN THE MID ATLC
PIEDMONT.

PACIFIC RECON FLIGHTS REQUESTED INTO THE CRITICAL UNCERTAINTY AREA
AHEAD OF THIS SYSTEM IN THE NE PACIFIC. IF A FLIGHT IS AVAILABLE
THIS DATA COULD GET INTO THE MODEL SYSTEMS BY THE RUNS OF SUNDAY
00Z/12Z 30 JAN.

RAUSCH/ROSENSTEIN

II. PACIFIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS
2. SUCCEEDING DAY OUTLOOK:
A. P73/ 43.9N 172.3E(DROP 11)/ 30/1200Z


Second Mission added as well today for Monday...

NOUS42 KNHC 281700
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1200 PM EST FRI 28 JANUARY 2011
SUBJECT: WINTER STORM PLAN OF THE DAY (WSPOD)
VALID 29/1100Z TO 30/1100Z JANUARY 2011
WSPOD NUMBER.....10-059

I. ATLANTIC REQUIREMENTS
1. NEGATIVE RECONNASSSANCE REQUIREMENTS.
2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.

II. PACIFIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS
2. SUCCEEDING DAY OUTLOOK:
A. P71/ 44.9N 170.7E(DROP 11)/ 31/1200Z

[downsouthman1]

Our Tuesday storm is now showing up on GOES West Water Vapor Loop, spinning well West of WA/OR.

http://www.atmo.arizona.edu/products/wx ... 0mbwv.html

[gboudx]

The HPC discussion reads like a mouthful of marbles to me. It sounds like they are saying, "no snow for you southern plains".

[downsouthman1]

The HPC discussion reads like a mouthful of marbles to me. It sounds like they are saying, "no snow for you southern plains".

That's what I thought too.

Has anyone else noticed that the Baja Low seems to be moving SSW!?

[BigB0882]

The HPC discussion reads like a mouthful of marbles to me. It sounds like they are saying, "no snow for you southern plains".

That's what I thought too.

Has anyone else noticed that the Baja Low seems to be moving SSW!?

LOL! Now I feel like it is hurricane season and we are wobble watching. Let the fun begin!

[orangeblood]

pacific recon data to be ingested into Sunday's model packages. So by Sunday we should have a much clearer picture of this coming week. Until then everyone needs to back off the ledge, at least those in North Texas.

[Tireman4]

I am still thinking Monday might be when we might even know more....

What I mean is that this is so mixed up, the models are in disagreement and pros are still figuring this out....

[Portastorm]

I like this afternoon forecast discussion out of NWS Lubbock. If you read it carefully, the forecaster discusses the key issues at play (phasing, strength of trough, depth/progress of Arctic air, etc.). Here is the relevant snippet below.

**********

FOCUS THEN SHIFTS ADVERTISED WINTRY PRECIPITATION POTENTIAL AS A
STRONG COLD FRONT AND AN UPPER LEVEL LOW/TROUGH APPROACH THE AREA
MONDAY NIGHT. 12Z RUNS HAVE PRETTY MUCH UNIVERALLY TRENDED TOWARD
A DRIER SOLUTION WITH A DELAYED FRONTAL PASSAGE. THE PROBLEM SEEMS
TO LIE WITH THE SPLIT FLOW ALOFT AND WHETHER THE TROUGH IN THE SRN
STREAM THAT UNDERCUTS THE NERN PACIFIC UPPER RIDGE WILL PHASE WITH
NRN STREAM ENERGY OVER THE HIGH PLAINS. 12Z RUNS NOW EJECT A
WEAKENED FORM OF THIS TROUGH ACROSS THE SRN HIGH PLAINS MONDAY
NIGHT WHILE HOLDING BACK THE VAST MAJORITY OF THE UPPER ENERGY
OVER THE GREAT BASIN. SHOULD THIS TREND VERIFY PRECIP CHANCES WILL
END UP CONFINED TO THE NERN ZONES MONDAY NIGHT INTO EARLY TUESDAY
WHILE THE COLD FRONT WOULD NOT ENTER THE FCST AREA UNTIL LATE
MONDAY NIGHT. CURRENT MODEL TIMING THEN TRENDS TOWARD A RAIN OR
FREEZING RAIN TYPE SCENARIO LIKELY AFFECTING A SMALLER PORTION OF
THE FCST AREA THAN PREVIOUSLY EXPECTED. FOR NOW WILL BE RATHER
CONSERVATIVE IN CHANGING THE FCST AS MODELS TEND TO HAVE DIFFICULTY
WITH THESE SPLIT FLOW PATTERNS /ALTHOUGH THE CONSISTENCY AMONGST
THE RUNS THIS MORNING IS IMPRESSIVE/. AS SUCH WILL PUSH THE COLD
FRONT BACK 6 TO 12 HOURS THUS RAISING THE NEED TO INCREASE MONDAY
NIGHT LOWS AND IN TURN FAVORING A MOVE TOWARD RAIN MONDAY EVENING
AND AWAY FROM SNOW MENTION MONDAY OVERNIGHT. WILL KEEP POPS PRETTY
MUCH AS INHERITED FAVORING NERN ZONES...DROPPING TOWARD SLIGHT
CHANCE HEADING WWD TOWARD THE NM LINE.

LATTER PERIODS ATTM LOOK TO REMAIN QUIET. ENERGY OVER THE GREAT
BASIN IS PROGGED TO CUT OFF AND SLOWLY SINK TO THE SOUTH WITH ITS
ENERGY TOO FAR WEST TO AFFECT THE FCST AREA WITH ANY PRECIP. ONE
ARTIFACT WILL BE TO KEEP SFC RIDGING OVER THE PLAINS FOR SEVERAL
DAYS...AND THUS WARMING TREND TOWARD THE END OF NEXT WEEK LOOKS TO
BE MODEST IN MAGNITUDE.

[wxman57]

I was just going through some old maps/forecasts I'd saved from previous events. One that I recall which looks VERY similar is the November 25th, 1993 ice storm across Texas. It was the Thanksgiving that the Cowboys were playing and Leon Lett made that bad play.

I'm looking at the projected upper-air flow and surface low/front projections from the models back then and they're nearly identical to the current projections of upper-air and surface pattern for next week.

In 1993, there was a large upper low that pinched off over Utah/Nevada and the southwest U.S. as Arctic air flowed down the Plains lee of the Rockies. The models back then developed a low center in northeast New Mexico and tracked it across the TX Panhandle and Oklahoma. The low was forecast to slow down the front until it moved off to the east, driving the front through southeast Texas by Friday, the 26th. Sound familiar?

What happened? The Arctic front just steamed on south, reaching the Gulf of Mexico before sunrise on the 25th, a day before the models had forecast it to arrive from 3-4 days out. Cold Arctic air invaded Texas a day ahead of "schedule". The thin layer of sub-freezing air resulted in widespread freezing rain across the state. I remember the Dallas are NWS office said "we just can't see the moisture" for any precip a day or two before the front moved through.

The current setup is quite similar to November of 1993, so we have to watch for the cold Arctic air to move south much faster than forecast. And we may not see a low development in the Southern Plains as the models currently forecast.

[Portastorm]

OK, allow me to gush for a bit (and I hope I don't embarrass the guy) ... but I hope everyone here realizes how amazing it is that we have a longtime professional meteorologist like Wxman57 who not only shares his wisdom with us, but also can offer this kind of historical perspective on a developing situation. Storm2K is very fortunate.

That is a fascinating post. Thank you VERY MUCH for sharing, Wxman57!

Now if you'll excuse me, I have to climb back down and off this ledge.

[Rgv20]

The 9zSREF has a 1055 High just north of Montana 00z Tuesday