New Year's Eve Weather

[srainhoutx]

Reaching for straws I'm afraid srain.

I had a dream last night I was standing in a pasture with my son watching a black as midnight squall line approaching us over the tree line. We joyfully headed inside the house and look at radar and saw white and pink behind the front heading south with the plummeting temperatures! A feeling of euphoria swept over me in my dream!

The freakin alarm then woke me up and I looked outside and started to cry.

I remember a wise person saying be careful what you wish for. That said, keep on dreamin, redneckweather. I like your way of thinking. Meanwhile, the differences between the GFS and the Euro raise an eyebrow regarding the Christmas Eve front. The Euro says, what front? lol

[wxman57]

Yeah, I noticed that. The Euro has south winds here the 24th-27th with ever-increasing temps. It does forecast a big storm across the Rockies and Southern Plains the 28th. That would push a cold front through Houston around then.

[srainhoutx]

Yeah, I noticed that. The Euro has south winds here the 24th-27th with ever-increasing temps. It does forecast a big storm across the Rockies and Southern Plains the 28th. That would push a cold front through Houston around then.

Look at this...looks like a pattern change to me...

Euro Day 10...




GFS Day 10.5...




GFS Ensembles Day 13...

[wxman57]

That pattern could bring us some thunderstorms between Christmas and New Year's.

[Paul]

interesting to see the EURO and GFS flip flopping...more to come I am sure....

interesting that I have been in Denver last week and the people were freakin out because they hadnt any significant snow...even the foothills were dry....weird winter to start....

good to be back....

[wxman57]

00z euro and GFS now agree on a weak frontal passage late on the 24th. A few light showers but no significant rain. Both also indicate a deeper southern stream storm around the 28th that MIGHT be able to bring some rain to Texas just before New Year's.

[srainhoutx]

Several things to watch in the Christmas Eve to New Years time frame. The storm track is shifting and that is a change. There appears to be a chance of severe weather to our NE with the Christmas Eve front. The front on the 28th is suggested by virtually all the global operational guidance (GFS, Euro, Canadian, & UKMET) to be a powerful Southern Plains storm. While the track will shift and certainly is not set in stone at this range, the fact that all medium range guidance is 'sniffing' out the storm brings some hope that it will be there in some form or fashion and end this run of a boring weather pattern.

[srainhoutx]

I may well be heading West just after Christmas for some R & R...

HPC:

...WEST...

AN ONSLAUGHT OF HEAVY OROGRAPHIC SNOW IS EXPECTED TO IMPACT A GOOD
PORTION OF THE WESTERN STATES THIS FCST PERIOD... BASICALLY FROM
SAT THROUGH MON. A LARGE AND SLOW MOVING CIRCULATION OVER THE
NRN/NERN PAC WILL STEER A SERIES OF PAC DISTURBANCES AND ANOMALOUS
DEEP TROPICAL MOISTURE INTO CA AND PROCEED/TRANSPORT DOWNSTREAM
THROUGH THE INTER-MOUNTAIN WEST. THE RESULTANT WILL BE A
TREMENDOUS DEVELOPING SNOW-PACK FROM THE SIERRA/NRN CA MTNS AND OR
CASCADES THROUGH MUCH OF THE INTERIOR WRN TERRAIN.

A VERY ACTIVE AND PERSISTENT WSWRLY TO NERLY 250 MB UPPER JET OF
150 KTS WILL STEER THESE IMPULSES INTO THE WEST... WHILE 00Z GFS
MOISTURE FLUX ANOMALIES ARE OFF THE CHARTS... BASICALLY 4 TO 5
TIMES ABOVE AVG. THE COMBINATION OF THE STRONG FORCING...
IMPRESSIVE AVAILABLE PAC/TROPICAL MOISTURE TRANSPORT AND
BROAD/ENHANCED UPPER DIVERGENCE WILL LIKELY PUMMEL THE TERRAIN
WITH MORE FEET THAN SINGLE INCHES OF SNOW.

ON SAT... A GENERAL AND BROAD ONSHORE COMPONENT WILL BE IN PLACE
FROM OR SOUTH DOWN THE CA COASTLINE. THIS UNIFORM FLOW SHOULD
ENHANCE ACCUMULATIONS FROM THE OR CASCADES/NRN CA MTNS AND SIERRA
INTO THE SAWTOOTH OF ID/NRN AND CENTRAL WASATCH AND CO ROCKIES. A
MORE SIGNIFICANT SHORT WAVE ON SUN WILL ROUND THE BASE OF THE
UPPER TROUGH AND GLIDE INTO NRN/CENTRAL CA. THE LOWERING OF
HEIGHTS AND MORE SWRLY TRAJECTORY SHOULD BE IDEAL FOR VERY HEAVY
SNOW ONCE AGAIN ACROSS THE NRN CA MTNS AND SIERRA INTO THE NRN
WASATCH/UINTAS. FINALLY ON MON... HEIGHTS CONTINUE TO DIG DOWN THE
WEST COAST DIRECTING THE DEEP MOISTURE THROUGH CA INTO THE ENTIRE
WASATCH/CO ROCKIES. WHEN ALL IS SAID AND DONE...EXPECT THE CA
SIERRA TO SEE 4 TO 8 FEET... IF NOT MORE... OF SNOW OVER THE THREE
DAY FCST PERIOD...WHICH COULD VERY WELL BE HISTORIC.

[srainhoutx]

The 12Z GFS suggests the Christmas Eve front is still on schedule and a robust storm takes shape across the Southern Plains and heads E. There are some positive signals of a pattern change as well. The Pacific appears to be heading toward a more favorable period and we are seeing signs of an MJO pulse that could invigorate the STJ. Also of note is the rising PNA depicted in the guidance as well. The Pacific flow of storms appears to reamain very active and hopefully the more active period will produce some better chances of moisture for TX/OK...

PNA heading toward a netural/slightly positive regime after being negative since mid November...



AO is expected to stay negative after dropping to a record negative range today (-5.17)...

[sleetstorm]

I wonder what winter weather will/might be coming in the first new month of the second new decade of the 21st century & third millennium?

[srainhoutx]

Some changes with the 00Z runs over night. The front is still a go for Christmas Eve. In fact, it appears to be colder than previous runs (GFS and Euro) have shown and looks to stay cool in the week leading up to New Years Eve with what? Moisture!

12192010 00Z GFS_3_2010121900_F252_PCPIN_96_HR.png

12192010 00Z GFS_3_2010121900_F276_SNOWIN_SURFACE.png

The Christmas Storm looks to be a strong Southern Plains to East Coast event and the HPC is coming onboard with it as well...

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
400 AM EST SUN DEC 19 2010

VALID 12Z THU DEC 23 2010 - 12Z SUN DEC 26 2010


...INCREASING CHANCES FOR A MAJOR WINTER STORM FROM THE MIDWEST TO
THE EAST COAST TOWARD CHRISTMAS...

USED THE 00Z ECMWF FOR THE PRELIMINARY FRONTS AND PRESSURES FOR
DAYS 3 THROUGH 7. THE 00Z ECMWF WAS IN PHENOMENALLY GOOD
AGREEMENT WITH THE GFS WITH THE TRACK AND RELATIVE INTENSITY OF
THE MAJOR WAVE TRACKING ACROSS THE MIDWEST DAY 5 TO OFF THE MID
ATLANTIC COAST DAY 7. FURTHERMORE...THE 00Z/19 GEFS MEAN IS VERY
CLOSE TO THE 12Z/18 ECENS MEAN WITH THE SAME SYSTEM...ADDITIONALLY
PARTICULARLY ROBUST SUPPORT. USED THE ECMWF SINCE ITS DETAILS
TEND TO VERIFY BETTER IN THE MEDIUM RANGE...WHICH MAY HELP TO SORT
OUT THE NOISY SHORTWAVE ENERGY RESURGING INTO THE WEST THIS
PERIOD.

[sambucol]

Is that snow for our area on that map, Steve?

[srainhoutx]

The second map is snow across Central/N TX and OK, sambucol and perhaps trace amounts near here. The first map is a 96 hour precip (rain) estimate.

[wxman57]

Is that snow for our area on that map, Steve?

I've found that the "trace" amounts areas on the GFS snow map are fairly meaningless as far as seeing any snow. It's the 1" or greater area (green area) that are significant. In this case, the GFS is indicating a possible snow/ice event for north Texas and Oklahoma and eastward. However, that all depends on a passing upper-level feature both existing at that time and that it has a good supply of cold air to work with.

Remember about 10 days ago, the GFS was forecasting a massive cold front to move south out of Canada and across Texas right before Christmas? That cold front is turning into a weak reinforcing shot of cool air. Since the GFS has been having trouble predicting both of those factors beyond 5-7 days, I'd look for some significant changes between now and then. But I do think there may be a chance for something frozen up in NE TX and OK. Rain here, if we're lucky.

[srainhoutx]

HPC Morning update does offer some more details concerning the Christmas Eve Storm potential...

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
900 AM EST SUN DEC 19 2010

VALID 12Z THU DEC 23 2010 - 12Z SUN DEC 26 2010

THE FORECAST SPREAD/SOLUTION ENVELOPE REMAINS SMALLER THAN NORMAL
AS MODELS AND ENSEMBLES AGREE QUITE WELL WITH DEVELOPMENT AND
EVOLUTION OF AN AMPLIFIED AND STEADILY PROGRESSIVE MID-LATITUDE
FLOW PATTERN FROM THE ERN PACIFIC ACROSS THE LOWER 48 OVER THE
COMING HOLIDAY WEEK. THIS STORMY PATTERN WILL BE HIGHLIGHTED BY
THE INLAND SURGE OF DYNAMIC/COOLING/DESTABILILZING SHORT RANGE ERN
PACIFIC TROUGH ENERGY ALOFT OUT FROM THE INTERMOUNTAIN
WEST/ROCKIES THU OVER/THROUGH A MID-UPPER LEVEL MEAN RIDGE
POSITION BEFORE DIGGING/AMPLIFYING SEWD ACROSS THE CENTRAL US AND
INTO AN ERN SEABOARD BY CHRISTMAS. THIS SETS THE STAGE FOR
POTENTIAL FOR A SIGNIFICANT SWATH OF WINTER PCPN ACROSS THE NATION
AND LEADING TO WELL ORGANIZED HOLIDAY WEEKEND EAST COAST WINTER
STORM CYCLOGENESIS. UPSTREAM FLOW ACROSS THE CENTRAL THEN ERN
PACIFIC BY THEN BECOMES MORE OF A MESS HOWEVER WITH INCREASING
SOLUTION SPREAD...SO FORECAST CONFIDENCE DECREASES RAPIDLY WITH
TIME THERE AND INLAND INTO THE WRN US EVEN THOUGH THE BULK OF
GUIDANCE DOES ALLOW ANOTHER POTENT MID-UPPER LEVEL TROUGH TO REACH
THE WEST COAST CHRISTMAS WEEKEND WITH A RENEWED THREAT FOR MORE
HEAVY PCPN/UNSETTLED WEATHER SLAMMING INLAND.

OVERALL...WHILE GUIDANCE DOES OFFER SOME DIFFERENCES AN OVERALL
SOLUTION CLOSE TO THAT SIMILARILY PROVIDED BY RECENT GFS/ECMWF AND
GFS/ECMWF ENSEMBLE MEANS SEEMS REASONABLE AND RUN TO RUN
CONSISTENT. THE MANUALLY ADJUSTED UPDATED HPC PRELIM GUIDANCE
PACKAGE MAINTAINED CLOSE CONTINUITY WITH ONLY SOME MINOR TWEAKS
FROM OUR EARLIER ISSUANCE. HEAVY SENSIBLE WEATHER FOCUS IS OFTEN
MORE FICKLE AS PER IMPORTANT SMALLER SCALE DIFFERENCES AND
INTERACTIONS THAT STILL FALL WITHIN NOISE LEVELS AT MEDIUM RANGE
TIME SCALES...BUT THE FLOW REGIME CERTAINTY SUPPORTS A BUSY/STORMY
HOLIDAY PERIOD.

[srainhoutx]

Some shifts in guidance for the Christmas Eve Storm have occurred overnight. A very complex and complicated forecast is ahead and expect some changes. The Euro, Canadian and UKMET has trended further S and stronger with an Upper Air feature (closed low) tracking across Southern California, Desert SW into the TX Panhandle and dropping ESE into LA, while the GFS keeps an open wave/trough further N exiting CO into KS and heading E. Now what does that mean? It appears more moisture may be involved with the Christmas Eve front and perhaps a 6-12 hours slower arriving Friday afternoon/evening versus the faster GFS solution. Also of note with the Euro solution is the chance of rain and possibly elevated storms across the TX Panhandle, W TX, N TX/OK along and N of the Upper Low track, should it verify. Christmas Day still looks cold and dry for now, but if the Euro solution is correct, there may well be some wrap around cloudiness/very light moisture and stiff northerly winds as a surface low pressure deepens over LA. The Euro solution also opens the door to a Major Christmas Weekend Winter Storm along the East Coast as well with very heavy snowfall totals and even a 'hint' of an Archambualt Signature for that area. In the longer range the pattern as well as guidance suggests a bonified chance at some much needed rain in Southern, SE TX as a coastal low/trough develops during the pre New Years Eve time frame. We have been hoping for some sort of pattern change and this may well be it.

Forecaster Roth in the HPC morning Prelim Update...

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
757 AM EST MON DEC 20 2010

VALID 12Z FRI DEC 24 2010 - 12Z MON DEC 27 2010

...SIGNIFICANT PRECIPITATION EXPECTED TO CONTINUE ALONG AND JUST
INLAND OF THE WEST COAST FOR ANOTHER 5 TO 6 DAYS...

TELECONNECTIONS WITH A RIDGE MOVING SLOWLY ACROSS THE PRAIRIE
PROVINCES OF CANADA FAVORS NEARLY CLOSED CYCLONES ALOFT MOVING
UNDER ITS BASE THROUGH THE NORTHERN ROCKIES/NORTHERN PLAINS LATER
THIS WEEK...A SOLUTION BEST INDICATED BY THE 00Z CANADIAN AND 00Z
GEFS AND ECMWF ENSEMBLE MEAN GUIDANCE. OTHERWISE...ENERGY MOVING
OUT INTO THE MIDWEST EARLY ON IS EXPECTED TO SCOOP UP SOME
SHORTWAVE ENERGY MOVING OUT OF THE SOUTHWEST AND SOUTHERN PLAINS
BEFORE LOSING LATITUDE AS IT MOVES THROUGH THE EAST UNDER THE BASE
OF A PORTION OF THE POLAR VORTEX DESCENDING THROUGH EASTERN
CANADA. THIS SOLUTION IS BEST REPRESENTED BY THE 06Z GFS/00Z
CANADIAN/00Z ECMWF AND GEFS MEAN GUIDANCE. OVERALL...USED A
COMPROMISE OF THE 00Z CANADIAN/00Z ECMWF ENSEMBLE MEAN...AS THE
06Z GFS MIGHT BE A TOUCH TOO QUICK PER ITS OCCASIONAL QUICK BIAS
WITH SYSTEMS IN THE WESTERLIES...WHICH LED TO GOOD CONTINUITY WITH
THE PRESSURES FROM SUNDAY AFTERNOON. THIS PATTERN SHOULD REMAIN
MOIST ALONG THE WEST COAST...AND COLD ACROSS THE NORTHERN
PLAINS/MIDWEST/MUCH OF THE EAST.

WEST AND PLAINS THIS WEEKEND INTO EARLY NEXT WEEK...
WITH STRONG RIDGING PERSISTING ACROSS WESTERN AND CENTRAL CANADA
THROUGH THE PERIOD...A PACIFIC SYSTEM IS EXPECTED TO MOVE THROUGH
THE REGION UNDERCUTTING THE RIDGE. TIMING ISSUES EXIST...WITH THE
06Z GFS THE QUICKEST. SINCE THE RIDGING ACROSS WESTERN AND
CENTRAL CANADA IS SHOWING SOME PROGRESSION IN THE NORTHERN
STREAM...A SLOWER PROGRESSION IS LIKELY IN THE SOUTHERN
STREAM...SO WENT WITH THE NON-06Z GFS GUIDANCE HERE.
OVERALL...THE 00Z CANADIAN HAD THE BEST ENSEMBLE MEAN SUPPORT...SO
WENT WITH A 00Z CANADIAN/00Z ECMWF ENSEMBLE MEAN COMPROMISE WITH
THIS SYSTEM. SIGNIFICANT PRECIPITATION ACROSS THE WEST IS
EXPECTED FOR ANOTHER 5 TO 6 DAYS...WITH LOCAL LIQUID EQUIVALENT
AMOUNTS OF 10 INCHES POSSIBLE ACROSS THE OLYMPIC
PENINSULA...NORTHERN COASTAL RANGES OF CALIFORNIA AND SISKIYOU
RANGE...AS WELL AS THE COASTAL RANGES OF SOUTHERN CALIFORNIA AND
SOUTHERN WASATCH DURING THIS TIME FRAME.

SOUTH AND EAST...
THE 00Z ECMWF IS SLOW/MORE CLOSED THAN THE OTHER DETERMINISTIC
GUIDANCE WITH ENERGY MOVING THROUGH THE SOUTHWEST AND SOUTHERN
PLAINS...WITH LESS THAN ONE-QUARTER OF THE OVERALL 00Z GLOBAL
ENSEMBLE GUIDANCE SUPPORTING ITS SOLUTION...IMPLYING IT IS TOO
SLOW. TELECONNECTIONS FARTHER NORTH IMPLY STRONGER ENERGY SHOULD
BE MOVING THROUGH THE NORTHERN TIER OF THE COUNTRY...WHICH SHOULD
ABSORB THE SOUTHWESTERN ENERGY AS IT MOVES INTO THE
PLAINS/MIDWEST. EITHER WAY...A SURFACE LOW IS EXPECTED TO MOVE
THROUGH THE SOUTHERN PLAINS INTO THE DEEP SOUTH OR TENNESSEE
VALLEY OFFSHORE THE VIRGINIA CAPES. THE BIGGER QUESTION IS HOW
CLOSE TO THE COAST THIS CYCLONE WILL TRACK. THE ECMWF BECOMES THE
MOST NORTHWESTERLY OF THE GUIDANCE AT THE SURFACE...AND IF THIS
SURFACE LOW WERE MOVING UP THE EAST SIDE OF AN AMPLIFIED TROUGH
RATHER THAN A PROGRESSIVE CLOSED CYCLONE A MORE COASTAL TRACK FOR
NEW ENGLAND WOULD MAKE SENSE. SINCE THIS DOES NOT APPEAR TO BE
THE CASE...AND THE 00Z ECMWF ALSO APPEARS TOO FAR NORTH WITH ITS
CYCLONE IN CANADA...ITS CYCLONE TRACK ALONG THE EAST COAST IS
PROBABLY TOO FAR NORTH/TOO CLOSE TO THE COAST. THE OTHER
GUIDANCE...INCLUDING THE ENSEMBLE MEAN SOLUTIONS...MOVE THIS
SYSTEM CLOSER TO THE GULF STREAM...A NATURAL BAROCLINIC ZONE/AREA
OF TEMPERATURE GRADIENT OFFSHORE THE EAST COAST...WHICH APPEARS
MORE LIKELY CONSIDERING THE FLOW PATTERN ALOFT. DUE TO
PREFERENCES ACROSS THE PLAINS AND WEST LATE IN THE PERIOD...CHOSE
THE 00Z CANADIAN HERE...ALTHOUGH THE 00Z ECMWF OR 00Z GEFS MEAN
ARE REASONABLE ALTERNATIVES. EITHER WAY...WINTER WEATHER SHOULD
SPREAD FROM THE CENTRAL PLAINS EASTWARD ACROSS THE TENNESSEE
VALLEY THROUGH THE MID-ATLANTIC STATES...AS WELL AS SNOW SHOWERS
UNDER THE BASE OF THIS SYSTEM ACROSS THE GREAT LAKES AND
NORTHEAST. THE IMPACT OF THIS SYSTEM ACROSS THE NORTHEAST REMAINS
SOMEWHAT OF A QUESTION MARK...BUT FOR THE TIME BEING...THE 00Z
ECMWF LOOKS LIKE A LOWER PROBABILITY ALTERNATIVE SCENARIO.

ROTH

[srainhoutx]

The NAM has started. Let's see if the 'night crew' is awake in this dull, boring weather pattern...

[Ptarmigan]

Looks like the cockroach clouds rolled in. So, no total eclipse for viewing. I have been awaiting it for years. I need cans of RAID to kill off the clouds so I can see the eclipse.

[wxman57]

Sky has cleared up now. Stratus deck dissipated after sunset. Moon is nearly overhead and quite visible. Moon enters the umbra (darker part of the Earth's shadow) around 12:30am and should be completely covered by around 1:20am, I think.

[wxman57]

So much for the clearing sky, Now the fog is starting to form. Might see a glimpse of the moon when it's eclipsed, but that may be through a fog and stratus layer. Not worth staying up for that.