New Year's Eve Weather

[sleetstorm]

Would any of you care to itiate a winter 2010-2011 thread? If not then I will be happy to do so.

[Kludge]

The GFS is coming in a bit wetter/stronger with the Upper Low. We'll see what the temps will bring...this appears to be a step toward the 12Z Euro solution...

Thanks a bunch, Srain... for the continual and informative updates...! Your research and optimism is the sustenance this board wants and needs right now...especially in this period of la-nada weather.

The models seem to be increasing the strength of the Thurs-Fri "storm" for us with each run. Let's hope we're all blessed with a heavy (but non violent) squall on Christmas Eve, followed by a very chilly and seasonal Christmas Day.

[Paul]

the 18Z though la la land at 276hr is interesting...

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_276l.gif

[Andrew]

Would any of you care to itiate a winter 2010-2011 thread? If not then I will be happy to do so.

I think it would be more organized if continue creating topics for the month and not the whole season. Right now I don't see any need to create another topic but in the future I am sure we will need a January discussion thread. For now I think we should stick to this thread.

[Andrew]

the 18Z though la la land at 276hr is interesting...

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_276l.gif

Now look at the 00z.



As expected little consistency so far. I expect the GFS will go back and forth many times before latching onto a certain pattern.


Also the GFS has the Christmas front slower and wetter.

[srainhoutx]

Yep. That is rain and elevated storms you are seeing in the HGX forecast. It's been a long time coming. In fact if the Euro solution is correct, the cold core Upper Low will pass near/over SE TX on Friday afternoon/evening. Should that occur we may even see some small hail.

[texoz]

The west coast is getting pounded with unbelievable amounts of rain/snow, with more to come over the next couple of days.

http://news.yahoo.com/s/ap/us_california_storm

[srainhoutx]

The west coast is getting pounded with unbelievable amounts of rain/snow, with more to come over the next couple of days.

http://news.yahoo.com/s/ap/us_california_storm

I've been following the Sierra Nevada storms very closely for days. What is happening is not a typical La Nina pattern at all. We are seeing records fall right and left in California, both in snow fall as well as rain amounts. Stunning pattern folks and it will not let up for long after Christmas as well.

[srainhoutx]

E-mail from Jeff...

Several changes needed this morning…

Sea fog has developed and has socked in the coastal locations from Galveston to Corpus Christi. Visibilities are running in the 1/8 of a mile to 1/2 of a mile mainly along the coast and about 20 miles inland. Cold front currently just north of College Station is making decent southward progress, and latest model guidance now brings this front deep into SE TX today and tonight (change 1). Air mass north of this boundary over N TX is in the 30’s/40’s so there is some fairly cold air lurking just to the north. Highs will need to be lowered across our northern counties for this afternoon and tonight and across most of the area for Thursday (60’s instead of the 70’s, change 2). Not sure how far south the front will actually make it before it pulls up stationary, but it could ooze south of I-10 tonight. Clouds/drizzle/fog will be likely both ahead of the front and behind the boundary as a moist air mass resides across the area. If the front does make it to the coast, then sea fog issues could abate some, but I am not confident the front will make it that far south and the coastal locations could stay locked in the sea fog bank through Friday.

Next item is the strong upper level storm system headed for the region on Christmas Eve. 00Z model guidance has come in significantly stronger, wetter, and slower with this event. Track of mid/upper level low pressure system Friday afternoon/night places SE TX in a favorable position for strong dynamical lift along and ahead of the SE moving cold front. Appears enough moisture will be in place for the development of widespread showers/thunderstorms Friday afternoon/night ahead of this feature (change 3). Air mass does appear to become unstable enough to support a chance of thunderstorms Friday night. Rain chances will need a boost into the 40-60% range with the highest chances N of HWY 105. Widespread rainfall amounts of .25 to 1.25 inches will be possible with highest amounts up north and lowest amounts toward the coast/Matagorda Bay.

Strong cold front will blast through the area Friday night and Saturday morning with strong cold air advection developing in its wake. Temperatures will fall a good 20-25 degrees post front. GFS guidance shows a high of 53 on Saturday, but the GFS has also been wanting to hang on to a low level stratus deck behind the departing upper level storm system. Given the slower solutions that have developed in the last 24 hours, low clouds may linger well into Saturday and this will result in temperatures possibly holding in the 40’s much of the day…if clouds clear out quickly highs will be in the low to mid 50’s (change 4). Cold polar high settles over the region Saturday night with clearing skies and light winds freezing temperatures are expected. Area will remain cold into next week with another freeze Monday morning and then another surge of cold air from the north on late Monday. Do not expect highs to reach 60 again until maybe Wednesday of next week after Friday.

With cold dome in place next week, short wave will enter northern MX and move eastward inducing coastal troughing along the lower TX coast. Isentropic lift will begin to generate clouds late Monday as a moist air mass is shoved up and over the surface cold dome in response to the approaching system over N MX. Expect increasing clouds and then rain to develop on Tuesday as the upglide pattern becomes established and upper level dynamics come into play. A little early to define rain chances and amounts, but at least we have a couple of shots over the next week at some decent rainfall.

Nor’Easter: Potential appears to be growing for some kind of winter storm up the US east coast this weekend. Models have been bouncing around with potential intensities and track of a major low pressure system that develops near the Mid Atlantic and then moves up the NE US coast. Potential is there for a major weather event impacting much of the US east coast after Christmas with very strong winds and heavy snows. If some of the latest models verify a major nor’easter with significant impacts will be possible the 2 days after Christmas creating very hazardous travel conditions both on the ground and in the air. In fact if the position of the “bombing” surface low is correct and its movement correct, snow will be measured in feet at many of the major cities in the northeast.

Note: Record high temperatures were tied or broken at College Station, IAH, and Hobby yesterday. The high of 82 at IAH broke the record of 81 in 1970 and was 18 degrees above normal. The high of 84 at College Station smashed the record of 79 from 1970 and was 22 degrees above normal.

[srainhoutx]

Big changes in the 12Z GFS. That model now suggests the Upper Low will pass over SE TX. The GFS had been further N and this is a big change.

[sambucol]

How does this affect our area?

[srainhoutx]

How does this affect our area?

It would suggest better chance at some much needed rain. Also, the CMC (Canadian) has come in wetter as well...

[Portastorm]

The 12z GFS run would be great ... we'd get almost .75 inches of rainfall here in Austin. A nice Christmas present!

[srainhoutx]

I know there is some interest concerning the weather beyond the local Houston area during the Christmas Holiday weekend. There is still some uncertainty concerning the big East Coast Winter Storm and the HPC spells out the forecasting challanges. Aslo of note is the active pattern to our West. That weather could be our next major discussion beyond the Christmas Eve storm/cold front...

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
217 PM EST WED DEC 22 2010

VALID 12Z SAT DEC 25 2010 - 12Z WED DEC 29 2010


...CONTINUED HIGH UNCERTAINTY WITH TRACK/IMPACT OF POWERFUL EAST
COAST/WESTERN ATLANTIC STORM SUN-MON...

AN AMPLIFIED ERN PAC TROF AND SHARPENING W-CNTRL NOAM RIDGE IN
PLACE AT THE START OF THE MEDIUM RANGE PERIOD EARLY SAT WILL
SUPPORT FURTHER DEEPENING OF AN EVOLVING ERN CONUS TROF WHOSE AXIS
SHOULD REACH THE EAST COAST AROUND DAY 5 MON. UPSTREAM FLOW
SHOULD TREND FLATTER WITH TIME AS ERN PAC TROF ENERGY LIFTS NEWD
INTO THE WEST BY SUN-MON AND CONTINUES EWD THEREAFTER... WHILE
ADDITIONAL ERN PAC ENERGY WITH GENERALLY MODEST AMPLITUDE
CONTINUES TOWARD/INTO THE WEST. THIS LOWER AMPLITUDE WRN FLOW IS
EXPECTED TO KICK OUT THE DEEP ERN TROF BY TUE-WED.


OPERATIONAL MODELS AND ENSEMBLES CONTINUE TO SHOW CONSIDERABLE
SPREAD WITH THE TRACK OF THE SYSTEM FCST TO DEEPEN AS IT TRACKS
FROM THE GULF COAST OR GULF OF MEXICO INTO THE WRN ATLC OR ALONG
THE EAST COAST. THE PAST 2-3 OPERATIONAL ECMWF RUNS HAVE
INDICATED A MASSIVE...DEEP...SLOW-MOVING CYCLONE HUGGING THE
CAROLINA AND MID ATLANTIC COASTS THE TWO DAYS FOLLOWING CHRISTMAS.
THE ECMWF AND UKMET WERE THE FIRST OF THE GLOBAL MODELS TO SWITCH
FROM TRACKING THIS WAVE ALONG 40N THROUGH THE MIDWEST...TO A
SUPPRESSED PATH ACROSS THE DEEP SOUTH. SINCE THIS ADJUSTMENT...
THE UKMET TRENDED EVEN FARTHER SOUTH...WITH THE ECMWF LOCKING ONTO
AN EVOLUTION THAT TAKES THE DEVELOPING LOW TO THE FLORIDA
PANHANDLE AND THEN SHARPLY UP THE EASTERN SEABOARD. THE 06Z GFS
HAS ALSO TRENDED TO A VERY SUPPRESSED SOLN ACROSS THE GULF...
ADDING SUPPORT FOR SUCH A SCENARIO FOR AT LEAST THAT PART OF THE
FCST.

THE TRACK OF THIS SYSTEM BEYOND THE GULF REGION STILL DEPENDS
HEAVILY ON SHRTWV DETAILS OF NRN STREAM FLOW THAT ORIGINATES AT
MID TO HIGHER LATITUDES. MODELS SOMETIMES HAVE CONSIDERABLE
DIFFICULTY WITH HANDLING HIGHER LATITUDE ENERGY UNTIL WITHIN A
COUPLE DAYS OF AN EVENT. OF PARTICULAR NOTE THE 00Z/06Z GFS ARE
ON THE SHARP/WWD ELONGATED SIDE OF THE FULL GUIDANCE SPREAD WITH
ENERGY OVER THE WRN GRTLKS/UPR MS VLY AS OF EARLY DAY 4 SUN. THIS
ORIENTATION OF FLOW LIKELY PLAYS A PART IN THOSE GFS RUNS TRACKING
THE DEEPENING WRN ATLC SFC LOW WELL OFF THE COAST. THE 00Z
GEFS/ECMWF ENSEMBLE MEANS OFFER MORE SUPPORT FOR A SHARPER AND
MORE N-S ORIENTED TROF THAN RECENT GFS RUNS. MEANWHILE THE PAST
TWO ECMWF RUNS ARE QUITE DIFFERENT WITH THEIR HANDLING OF A CLOSED
LOW TO THE E OF HUDSON BAY AS OF DAY 3 SAT... SO THE ECMWF ALSO
HAS QUESTION MARKS EVEN THOUGH THEIR RUNS ARE MORE SIMILAR FARTHER
SWD.

AS THE SFC LOW TRACKS NEAR THE EAST COAST THE 00Z ECMWF IS ON THE
WRN SIDE OF THE SPREAD OF 00Z ECMWF ENSEMBLE MEMBERS AND WWD OF
ALL 00Z GEFS MEMBERS WHICH ARE ADMITTEDLY SOMEWHAT LOWER IN
RESOLUTION. THIS CORRESPONDS TO THE OPERATIONAL ECMWF RUNS BEING
A DEEP EXTREME WITH THE CLOSED LOW ALOFT. ASIDE FROM THE DEPTH
ALOFT THE ECMWF MID LVL EVOLUTION DOES APPEAR SOMEWHAT MORE
COMPATIBLE WITH GEFS/ECMWF ENSEMBLE MEAN IDEAS THAN THE 00Z/06Z
GFS. THUS PREFER A SFC SOLN IN THE WRN HALF OF THE GUIDANCE
SPREAD AND CLOSER TO THE ECMWF THAN 00Z/06Z GFS... BUT IT IS TOO
EARLY TO SUBSCRIBE FULLY TO THE 00Z ECMWF SPECIFICS. THUS WILL
PREFER A BLEND CONSISTING OF 30 PCT EACH 00Z ECMWF AND 12Z/21
ECMWF RUNS WITH THE REMAINING 40 PCT OCCUPIED BY THE 00Z ECMWF
ENSEMBLE MEAN TO YIELD A COMPROMISE AROUND 2/3 TOWARD THE ECMWF.

AS FOR SENSIBLE WEATHER IMPACT... THERE WILL LIKELY BE A TIGHT
SNOWFALL GRADIENT ALONG/INLAND FROM THE EAST COAST... MAKING IT
DIFFICULT TO DETERMINE AS FAR IN ADVANCE AS MAY BE DESIRED WHICH
AREAS WILL RECEIVE SNOW AND HOW MUCH WILL ACCUMULATE AT A
PARTICULAR LOCATION. HOWEVER EVEN WHERE THERE IS LITTLE OR NO
SNOW THERE SHOULD BE A PERIOD OF BREEZY/WINDY CONDS OVER THE ERN
STATES. THIS SYSTEM WILL BE TRAILED BY ANOTHER SIGNIFICANT SURGE
OF COLD AIR INTO THE EAST WITH SOME DAYTIME READINGS REACHING AT
LEAST 15 F BELOW NORMAL SUN-MON... AND FREEZING TEMPS FOR LOWS
EXTENDING INTO THE NRN FL PENINSULA BY EARLY MON-TUE.


THE PREFERRED BLEND FOR THE ERN CONUS/WRN ATLC EVOLUTION TONES
DOWN THE 00Z ECMWF THAT IS ON THE SHARP/AMPLIFIED SIDE OF THE
ENVELOPE WITH THE MID LVL TROF ENTERING THE WEST ON DAY 4 SUN.
CONFIDENCE IN PARTICULARS OF ERN PAC TO PLAINS/GRTLKS FLOW
DECREASES AS AMPLITUDE OF THE MEAN FLOW LIKEWISE DECREASES AT
LEAST BRIEFLY. BY DAY 7 WED THE MOST COMMON IDEAS OF ENSEMBLE
MEANS ARE TOWARD A WEAK SHRTWV REACHING THE GRTLKS AND VICINITY...
A SHRTWV TROF NEARING THE WEST COAST... AND A MODERATE TROF
REACHING NWRN MEXICO. ECMWF RUNS FIT THE ENSEMBLE MEANS BETTER
THAN THE 00Z/06Z GFS WHICH ARE SLOWER. HOWEVER THERE IS THE RISK
THAT THE ECMWF/ECMWF MEAN COULD BE A LITTLE QUICK TO BREAK
DOWN/PUSH EWD THE RIDGE ALOFT REACHING THE ERN HALF OF NOAM BY
TUE. THE MOST SIGNIFICANT SENSIBLE WEATHER OVER THE WRN 2/3 OF
THE CONUS THIS PERIOD SHOULD BE OVER THE WEST... WITH SOME LOCALLY
MDT-HVY PCPN OVER CNTRL-NRN CA DURING THE FIRST HALF OF THE PERIOD
IN ASSOC WITH THE LEADING TROF EJECTING INTO THE WEST. DRIER
CONDS SHOULD PREVAIL ALONG THE SRN HALF OF THE WEST COAST
MON-TUE... BUT THE DAY 7 SHRTWV MAY PUSH MEANINGFUL PCPN SWD INTO
CA BY NEXT WED.


12Z UPDATE... FINAL FCST MAKES NO MEANINGFUL CHANGES TO THE
UPDATED PRELIM ISSUANCE. WITH THE GULF/WRN ATLC SYSTEM A MILD WWD
TREND IN THE 12Z GFS/GEFS MEAN HAS NARROWED THE SOLN SPREAD
SLIGHTLY OVER THE WRN ATLC BUT OTHERWISE PRIOR UNCERTAINTY
REMAINS. THE 12Z ECMWF HAS MAINTAINED CONTINUITY IN PRINCIPLE
WHILE THE 12Z CMC CLUSTERS NEAR THE GFS/GEFS MEAN. THE UKMET IS
SLOWEST AND ALSO EWD OF THE ECMWF. THE 12Z GEFS MEAN DOES OFFER
POTENTIAL FOR PCPN TO EXTEND FARTHER WWD THAN THE OPERATIONAL RUN
EVEN THOUGH THE GEFS MEAN SFC TRACK IS SIMILAR TO OR A FRACTION E
OF THE GFS. FARTHER WWD... ECMWF CONTINUITY AND 12Z
CMC/EXCESSIVELY SEPARATED UKMET SOLNS OFFER SUPPORT FOR A FAIRLY
SHARP/AMPLIFIED ERN PAC TROF ENTERING THE WEST ON SUN. DOWNSTREAM
THERE IS SOMEWHAT IMPROVED AGREEMENT WITH INCREASINGLY PROGRESSIVE
NRN TIER CONUS/SRN CANADA FLOW LATER IN THE PERIOD WITH THE 12Z
GFS TRENDING FASTER THAN 00Z/06Z RUNS AND 12Z ECMWF/CMC/GEFS MEAN
SIMILAR TO OR AT MOST A LITTLE SLOWER THAN THE 00Z ECMWF. 12Z
UKMET IS A FAST OUTLIER THOUGH. FINALLY THERE IS DECENT
CLUSTERING OF SOLNS WITH THE SHRTWV FCST TO NEAR THE WEST COAST AS
OF EARLY DAY 7 WED.

RAUSCH/CISCO

[Baseballdude2915]

12z GFS brings us a nice chilly pattern after Christmas, even colder after New Years Day. Hopefully we can see some verification, the GFS has been pretty spot on, even long range this year.

[sambucol]

12z GFS brings us a nice chilly pattern after Christmas, even colder after New Years Day. Hopefully we can see some verification, the GFS has been pretty spot on, even long range this year.

Any wintry mix possible in our future?

[srainhoutx]

Merry Christmas from HGX...

THE MODELS WERE THEN CONSISTENT IN PUSHING THE PACIFIC STORM
SYSTEM ACROSS THE SOUTHERN ROCKIES INTO THE SOUTHERN PLAINS BY
EARLY FRIDAY. THE MODELS ARE GENERATING BETTER QPF WHILE THE MODEL
SOUNDING FORECASTS ARE CONSISTENT WITH THUNDERSTORM CHANCES. WENT
WITH A NAM/GFS/ECMWF COMPROMISE IN ENDING THE RAIN BETWEEN 06Z AND
09Z SATURDAY MORNING.

[wxman57]

12z GFS brings us a nice chilly pattern after Christmas, even colder after New Years Day. Hopefully we can see some verification, the GFS has been pretty spot on, even long range this year.

Any wintry mix possible in our future?

Precip will be long gone on Christmas Day once the air gets cold enough. Nothing on the horizon. Don't expect anything this year.

[Ptarmigan]

I saw the forecast and that Christmas Eve night might be rainy and possibly storm. However, December 29-30 could see heavy rain. It is rare to see thunderstorms on Christmas Eve. The closest was back in 2002.

[srainhoutx]

The 00Z NAM is running. Will we see some moisture...

12232010 00Z NAM nam_500_012l.gif

12232010 00Z nam_500_030l.gif