January: Increasing Clouds/Rain & Warmer To End Month

[Andrew]

CMC still shows some possible Wintry mischief for next week but keeps the trof together more compared to the 12z run. Also this weekend looks rainy but we already knew that haha

[Andrew]

Euro (like all models) continue to indicate a lot of uncertainties for the upcoming forecast. First off this weekend the Euro continues to show the cutoff low that will drop down to the middle of Texas and push east. This run is a little farther north but still has the same general time frame as the previous runs and still has an abundance of moisture to work with. The tricky part of this run is yet again another solution is thrown out there for the end of next week. The Euro slows down the next ULL off the California coast by a lot! The cut off low doesn't even come into the picture (for Texas) until hour 216 or 240! The Euro does create a much stronger trough that extends all the way to the coast which allows for cold air advection to filter all the way down south. This would open the door to colder air and is a much colder run then the 12z run. Also the Euro does indicate some minor precipitation after the trough moves through. In all honesty between the GFS and Euro each model has been throwing out different solutions each run. That is a good indication that a big change is coming and I think the cmc might be on to something. It has been the most consistent so far even with its biases. As we move into next week models should come into line with a solution but one thing does look for sure and that is a pattern change is setting up into this weekend and into next week. Look out.

[srainhoutx]

Once again, as we saw in December, these closed cold core upper lows are a forecasting challenge at best. This morning we see Winter Storm Watches hoisted for New Mexico with Special Weather Statements for winter weather from El Paso, Midland/Odessa, to Amarillo. San Angelo has joined in the question of whether they will see wintery mischief across their area and even Dallas/Ft Worth is mentioning the possibility of a wintry mix to their W as the upper low treks E. Further S, rains and storms look likely beginning late Sunday into Tuesday morning. The SPC is mentioning even a possible tornado or two for S Texas as a Coastal Low develops. It does appear that heavy rains and storms are likely for Central/SE TX Sunday night into Monday night/early Tuesday morning. There still remain some uncertainty on the exact track of the U/L and precip could linger into Tuesday as the closed cold core upper low passes. The focal point for heavy rains will be along a stalled frontal boundary draped across Central/SE TX and wide spread 1-2 inch amounts, with isolated 4+ inch amounts possible where any training of heavy showers/storms develop.

A stronger push of colder air should follow on Thursday as a complex Winter Storm develops near the Great Lakes/Upper Mid West and a Canadian front dives S into the Plains in the wake of our passing storm early next week. Model volatility returns yet again with what happens with yet another upper low to our W on Wednesday/Thursday and just when that feature will eject E. Sound familiar? Various solutions and day to day, run to run solutions are offered by the various guidance and a very changeable forecast lies ahead regarding late next week. What is developing via guidance is heights increasing near/over Alaska and a break down of the Alaska Vortex that has brought record cold and snows to Cordova/Prince William Sound and cold temps are pushed into Western Canada and Arctic high pressure builds in the 1048-1055+ range and extends to the N Pole.

What often happen when a whole sale pattern change occurs are guidance flip flops and various solutions will change like the hands on a clock. It does appear we are entering a period where cold air intrusions are becoming more likely as we head into mid January. There still remain indications the a favorable MJO in phase 7-8, albeit weak will allow tropical forcing to keep the Pacific pattern active for us before relaxing later this month. A -AO/-EPO regime with a waffling +/-PNA is conducive to a cold and active pattern for the Western 1/2 to 2/3 of the North America while the East Coast remains warm with a +NAO or lack of Greenland blocking. The SE ridge tends to hold the cold air intrusions W as storm systems trek NE into the Ohio Valley or W of the Appalachians. All that said, stay tuned! We are entering a very changeable period and cold air intrusions well S into Mexico cannot be ruled out as a cross Polar flow may develop and depending on exactly where the Alaska Vortex is displaced, or takes up shop in Canada. My hunch is we are entering a very interesting period, weather wise so hang on. It could become a very bumpy ride...

[wxman57]

Not much change on overnight GFS runs. Rain starts tomorrow evening here and lasts until sunrise Tuesday. New runs shift the rain late next week to Saturday, making for a very miserable Olympic trials marathon on Saturday.

[tireman4]

Not much change on overnight GFS runs. Rain starts tomorrow evening here and lasts until sunrise Tuesday. New runs shift the rain late next week to Saturday, making for a very miserable Olympic trials marathon on Saturday.

Ahh man no....Sigh...We are either going to sit at Discovery Green and watch or jog from point to point to watch.

[srainhoutx]

The HPC Morning Update discusses the variability that is present regarding late next week into the weekend of the Olympic Trails Marathon and the upper low that could be lurking to our W...

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
731 AM EST SAT JAN 07 2012

VALID 12Z WED JAN 11 2012 - 12Z SAT JAN 14 2012

MODELS SHOW AN AMPLIFYING CENTRAL TO EASTERN US TROUGH DAYS 3-6
WITH THE TROUGH DEAMPLIFYING ON DAY 7. UPSTREAM...THE PRIMARY
UNCERTAINTY REVOLVES AROUND THE EVOLUTION OF A WAVE AND POTENTIAL
500 MB CLOSED LOW MOVING EITHER OFF THE CA COAST OR ONSHORE AND
EVENTUALLY INTO THE SOUTHWEST. ON DAY 7...A HIGH AMPLITUDE WAVE
OVER THE NORTHEAST PACIFIC MOVES TOWARDS THE PACIFIC NORTHWEST AND
BRITISH COLUMBIA. THE GENERAL AGREEMENT ON THE LARGE SCALE PATTERN
LED TO A CONSENSUS APPROACH...WITH MORE WEIGHTING TOWARDS THE 00Z
ECMWF ENSEMBLE MEAN IN LATER PERIODS. THUS...CONFIDENCE IS NEAR
NORMAL THROUGH THE PERIOD...WITH THE EXCEPTION OF BELOW NORMAL
CONFIDENCE IN THE SOUTHWEST WITH THE CLOSED LOW EVOLUTION. A
MULTI-MODEL/ENSEMBLE MEAN APPROACH WAS USED.

EASTERN AND CENTRAL US...

THE 00Z ECMWF/GFS/UKMET WERE IN GOOD AGREEMENT ON THE PROGRESSION
OF THE CLOSED LOW LEAVING TX ON DAY 3 AND MOVING INTO THE TN
VALLEY BY DAY 4 AND ACROSS THE NORTHEAST ON DAY 5. THIS SYSTEM
WILL BRING WIDESPREAD PRECIPITATION TO THE EASTERN US.

THIS SYSTEM WILL BE FOLLOWED BY A DEEP LAYER TROUGH MOVING EAST
FROM THE CENTRAL US. THE 00Z ECMWF CLOSED OFF A 500 MB LOW SOUTH
OF THE 12Z FRI RUN ON THU 12 JAN. THE 00Z ECMWF/GEFS MEANS/00-06Z
GFS/00Z UKMET SHOW THE DEVELOPING LOW FURTHER NORTH NEAR LK
SUPERIOR ON THU. THE MULTI-MODEL/ENSEMBLE MEAN APPROACH MITIGATED
THE IMPACT OF THE ONE RUN ADJUSTMENT OF THE OPERATIONAL ECMWF.

THE MEAN EASTERN TROUGH STARTS TO DEAMPLIFY AND MOVE EAST ON DAYS
6-7...WITH THE 0Z GFS STANDING OUT FROM THE PACK OF SOLUTIONS BY
MOVING THE TROUGH FASTER THAN THE LARGE MAJORITY OF ECMWF/GEFS
ENSEMBLE MEMBERS/RESULTANT MEANS AND 12Z FRI-00Z SAT OPERATIONAL
ECMWF.

WESTERN US...

THE DRY PATTERN OF LATE IN THE PACIFIC NORTHWEST CONTINUES AS THE
DEPARTURE OF THE NORTHERN ROCKIES TROUGH ON DAY 3 IS FOLLOWED BY
THE APPROACH OF A DEEP LAYER RIDGE FROM THE NORTHEAST PACIFIC.
THIS RIDGE PERSISTS UNTIL DAY 7...WHEN THE NEXT NORTHEAST PACIFIC
TROUGH DEVELOPS AND DRIFTS TOWARDS THE COAST. THIS TROUGH IS
ANTICIPATED BY TELECONNECTIONS FROM THE PERSISTING UPPER RIDGE
SOUTH TO SOUTHWEST OF THE ALEUTIANS...AND SHOWN IN THE MAJORITY OF
MODELS/RUNS. THE 06Z GFS WAS AN OUTLIER WITH FASTER PROGRESSION OF
THE TROUGH...WITH BETTER CLUSTERING AMONG THE 12Z FRI-00Z SAT
ECMWF/ECMWF ENSEMBLE MEAN/00Z GFS.

SOUTH OF THE MEAN RIDGE POSITION...THE MODELS FORECAST A WAVE TO
MOVE SOUTH ACROSS CA AND ADJACENT COASTAL WATERS...AND POSSIBLY
INTO THE SOUTHWEST WITH TIME. THE MODELS AND ENSEMBLES SHOW
WEST-EAST VARIABILITY OF WHERE A CLOSED LOW DEVELOPS. THE 00Z
ECMWF DEVELOPMENT IS OFF THE COAST AND THE 00Z-06Z GFS/00Z UKMET
CLOSED LOW DEVELOPS ONSHORE. THE 06Z GFS MARKS THE EASTERN EDGE
OF THE CLUSTER OF SOLUTIONS WITH THE CLOSED LOW POSITION/TRACK
NEXT THU 12 JAN TO SAT 14 JAN. A MULTI-MODEL/ECMWF ENSEMBLE MEAN
APPROACH RESULTS IN SHOWING THE ELONGATED TROUGH ACROSS THE REGION
BUT NOT COMMITTING TO ANY ONE SOLUTION...GIVEN THE LARGE SPREAD
AND ABOVE NORMAL UNCERTAINTY AS TO WHERE THE CLOSED LOW WILL
DEVELOP WITHIN THE 500 MB TROUGH AXIS.

[wxman57]

Not much change on overnight GFS runs. Rain starts tomorrow evening here and lasts until sunrise Tuesday. New runs shift the rain late next week to Saturday, making for a very miserable Olympic trials marathon on Saturday.

Ahh man no....Sigh...We are either going to sit at Discovery Green and watch or jog from point to point to watch.

Look on the bright side - maybe it's good that the GFS is forecasting all day rain from 7 days out. What are the odds of it being right? The Euro has the front farther offshore next Fri/Sat and no rain here.

[srainhoutx]

A very wet and wintry solution is showing up via the 12Z NAM. Accumulating snow in New Mexico, W and N Central Texas as well as the Southern Panhandle is suggested with heavy rains/storms further S in the warm sector near the stalled frontal boundary. The Upper Low deepens over N Central Texas and a Coastal Low develops near Corpus setting the stage for a very active 3-4 days...

[tireman4]

Not much change on overnight GFS runs. Rain starts tomorrow evening here and lasts until sunrise Tuesday. New runs shift the rain late next week to Saturday, making for a very miserable Olympic trials marathon on Saturday.

Ahh man no....Sigh...We are either going to sit at Discovery Green and watch or jog from point to point to watch.

Look on the bright side - maybe it's good that the GFS is forecasting all day rain from 7 days out. What are the odds of it being right? The Euro has the front farther offshore next Fri/Sat and no rain here.

True. True. You really need to come out Wxman 57. Remember, this could be a once in a lifetime event.

[Portastorm]

Wow ... I just want to say thanks to Andrew, srainhoutx, and wxman57 for all the great analysis this morning. It's the most complete representation I have seen in ANY forum for this coming week of weather!

[sambucol]

Is there any very cold air on our horizon? Any wintry precip in our future?

[srainhoutx]

The 12Z GFS continues the trend of the NAM that was suggesting a wet and wintry several days across New Mexico and parts of Texas. The GFS also deepens the upper low over N Central Texas and drops plentiful beneficial rains in the warm sector along the stalled boundary and just N of the Coastal Low with higher totals suggested for drought plagued areas SW of Houston...

[Portastorm]

As the 12z GFS rolls in, it seems to be coming closer to the CMC solution for later next week. Interesting.

[srainhoutx]

The good news for those attending the Olympic Trails Marathon is the 12Z GFS is suggesting the front will pass on Thursday. The interesting features are a short wave trough to our W and a developing Coastal Low/trough along the Lower/Middle Texas Coast spreading over running precip as that low begins to strengthen...

01072012 12Z GFS f138.gif

01072012 12Z GFS f150.gif

01072012 12Z GFS f156.gif

[srainhoutx]

As the 12z GFS rolls in, it seems to be coming closer to the CMC solution for later next week. Interesting.

It was certainly a step in that direction, Portastorm. If the Canadian and Euro continue the trends, a very interesting end of the week could lie ahead...

[srainhoutx]

As I mentioned earlier this morning, we keep seeing these 1055+mb Arctic high pressure ridges showing up via guidance in NW Canadian. The 12Z GFS continues that trend and what we will need to monitor is the short waves that dive S out of Canada as the Polar Vortex relocates into Canada from Alaska and exactly where that feature becomes established. Interesting days ahead, gang...

[srainhoutx]

The 12Z Canadian is slower with the progression of the upper low for tomorrow through Tuesday. It also suggest a bit further S trek across Texas and heavier precip due to the slow nature of the Coastal Low and U/L feature...

[srainhoutx]

Regarding later next week, the 12Z Canadian is also faster with a developing Coastal Low near Corpus as the front dives into Texas on Thursday. Light wintry precip is suggested with that front across Oklahoma and N Texas and a lingering shortwave is suggested further W after the precip has ended. It is noteworthy that the Canadian is suggesting a developing Winter Storm just N of the Great Lakes and there are hints this may be where the Polar Vortex will become established. We will see...

[srainhoutx]

The longer range Canadian is out now via the PSU site and it does suggest the short wave I mentioned above does drop S and develop. Also of note is a secondary Coastal low/trough develops along the Middle Texas Coast with cold air in place spreading some light precip over that cold air at the surface. The feature near the Great Lakes is much stronger, suggesting this may well be in fact the new location of the displaced Vortex that has plagued Alaska for so long. Addition shortwave trough energy is poised to drop S into the Plains and very chilly air continues to spill S via the Canadian solution...

[srainhoutx]

The 12Z GFS Ensembles are in and suggest much chillier air and over running precip for late next week...