January: Calmer Pattern To End The Month

[srainhoutx]

Here are a couple of snippets from various NWS offices across the Region...

NWS Ft Worth/Dallas:

BOTH THE 30/00Z GFS AND ECMWF INDICATE AN ARCTIC OUTBREAK FOR
THE SOUTH PLAINS EARLY NEXT WEEK. BOTH MODELS INDICATE THAT A
STRONG POLAR VORTEX WILL MEANDER OVER THE NORTH POLE AND SLIDE
SOUTH OVER NORTHERN CANADA ON THE WESTERN PERIPHERY OF A DEEP
HUDSON BAY UPPER LOW. THIS POLAR VORTEX IS THEN EXPECTED TO MERGE
WITH A STRONG SHORTWAVE TROUGH THAT BOTH MODELS INDICATE IS
CURRENTLY SITTING SOMEWHERE JUST NORTH OF THE KOREAN PENINSULA.
THIS MERGER HELPS TO DEEPEN THE UPPER LEVEL LOW PRESSURE
SYSTEM...RESULTING IN A STRONG SOUTHWARD PUSH OF ARCTIC AIR
THROUGH THE PLAINS. NOW THIS IS STILL ALMOST 200 HOURS OUT IN THE
FORECAST...WITH THE MAIN PLAYERS NOT EVEN OVER OUR CONTINENT AT
THIS TIME...SO A LOT CAN CHANGE BEFORE EARLY NEXT WEEK ARRIVES.
HOWEVER IT IS MENTIONED HERE BECAUSE OF THE VERY GOOD AGREEMENT
BETWEEN THE OPERATIONAL GFS AND ECMWF. WENT WITH TEMPERATURES WELL
BELOW NORMAL FOR EARLY NEXT WEEK AS A RESULT OF THIS ARCTIC AIR
SIGNAL FOR THE REGION.

CAVANAUGH


NWS Norman, OK:

MODELS SHOW A STRONGER COLD FRONT AND AN UPPER SYSTEM MOVING ACROSS
THE REGION THIS WEEKEND. STILL SOME DIFFERENCES WITH THIS SYSTEM BUT
LOOKS LIKE COLD TEMPERATURES WILL AFFECT THE AREA SUNDAY INTO EARLY
NEXT WEEK AND PRECIPITATION WILL BE POSSIBLE SATURDAY NIGHT INTO
SUNDAY. WINTER PRECIP WILL POSSIBLE ACROSS PARTS OF THE FA THIS
WEEKEND... BUT STILL TOO EARLY TO TELL EXACTLY WHERE AND HOW MUCH SO
NOT SURE HOW BIG OF AN IMPACT THIS PRECIP MAY HAVE ON THE AREA.
MODELS SHOW ANOTHER SURGE OF EVEN COLDER AIR MAY SURGE INTO THE AREA
EARLY NEXT WEEK.



NWS Dodge City, KS

LONG TERM...(Tuesday through Sunday)
ISSUED AT 338 AM CST MON DEC 30 2013

The highlight of the extended is the change to colder again
Wednesday with an increased chance for light snow or flurries and
then expecting another blast of cold air by late next weekend.

As lee troughing deepens Tuesday, temperatures should respond
nicely as increasing southerly winds and sunshine will contribute
to warmer temperatures. However, the warming will be short lived
as a clipper type system moves out of the northern plains and into
the midwest by midweek. The trend in the forecast models has been
for the clipper to be a bit farther south. The associated short
wave trough, or at least the pva anomaly, appears to have a
chance to deepen a bit more as it tops the long wave ridge
position across the eastern Pacific. The associated cold front
will blast through my forecast area on Wednesday so there should
be falling temperatures during the afternoon, at least based on
current timing. With the intrusion of Arctic air and some upper
level support, there should be at least light snow or flurries
across about the northeastern half of my area.

The remainder of the week will have slightly moderating
temperatures in advance of yet another system expected sometime
during the weekend. This system will also have a chance to amplify
with the aforementioned ridge in place. The associated Arctic
airmass will likely be even colder than the midweek system. Beyond
the weekend, some of the deterministic runs of the GFS and ECMWF
are looking a little scary, that is if extreme bitter cold air is
considered scary. More on that later.

[srainhoutx]

As Ed mentioned, the GFS has suggested some freezing rain issues as far S as Houston. That said the agreement in the ensembles suggesting the Polar Vortex will drop very far S into North Dakota/Minnesota tends to raise an eyebrow and the first shot of Arctic air is scheduled to arrive this weekend with an even stronger re enforcing Arctic front early next week.

[srainhoutx]

The 12Z GEFS ensemble mean certainly paint a pattern that is more than capable of delivering Arctic air well S into the Inter Mountain West and Plains. This is hour 132, so we are not talking about something that is way out in the future in computer model land.

[MontgomeryCoWx]

That's a pretty Omega block.

[srainhoutx]

The 12Z deterministic European model suggests a sharp Arctic front pushing into our Region this coming Saturday. It also appears there is a bit of an upper level trough/low attempting to hang back to the W and hints of a Coastal trough/low near Brownsville. The Euro also drops the Polar Vortex into ND/MN allowing very cold air to sink well S into the Eastern 2/3rds of the United States

[MontgomeryCoWx]

Oh $%$#@... that is some record shattering cold for the Midwest.

[srainhoutx]

The 12Z Euro ensemble mean anomalies are further W with the trough at hour 144.

[srainhoutx]

PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST MON DECEMBER 30 2013

6-10 DAY OUTLOOK FOR JAN 05 - 09 2014

TODAY'S ENSEMBLE MEAN FORECASTS ARE IN GOOD AGREEMENT ON THE EXPECTED 500-HPA
HEIGHT PATTERN FOR THE 6-10 DAY PERIOD OVER NORTH AMERICA. ENSEMBLE MEANS FROM
THE ECMWF, GEFS, AND CANADIAN ENSEMBLES AGREE ON THE PREDICTION OF A 500-HPA
RIDGE EXTENDING FROM JUST OFF THE WEST COAST OF THE CONUS TO CENTRAL ALASKA.
MODELS AGREE ON BELOW-NORMAL HEIGHTS IN A BROAD TROUGH PREDICTED TO BE OVER THE
MIDDLE MISSISSIPPI VALLEY EXTENDING NORTHWARD TO HUDSON BAY. THE DETERMINISTIC
RUNS OF THE GFS SHOW SOME SIGNIFICANT DIFFERENCES IN THE PREDICTED TROUGH AXIS,
WITH THE 00Z AND 06Z MODEL RUNS PREDICTING A TROUGH AXIS ALIGNED WITH THE ROCKY
MOUNTAINS AND ABOVE NORMAL 500-HPA HEIGHTS IN THE EAST. YESTERDAYS 12Z AND
TODAY'S 00Z DETERMINISTIC ECMWF RUNS AGREE WITH THE ENSEMBLE MEANS, AS DOES
TODAY'S 12Z GFS DETERMINISTIC RUN, THUS THE ECMWF ENSEMBLE MEAN SOLUTION MOST
HEAVILY WEIGHTED IN TODAY'S BLEND.

THERE IS VERY GOOD AGREEMENT FOR SIGNIFICANTLY BELOW NORMAL TEMPERATURES IN THE
NORTH-CENTRAL CONUS UNDER EXPECTED NORTHERLY UPPER LEVEL FLOW. MOST TOOLS BASED
ON LOW LEVEL TEMPERATURES FROM THE MODELS FAVOR ENHANCED CHANCES FOR
BELOW-NORMAL TEMPERATURES THROUGHOUT MOST OF THE CONUS, EXCEPT FOR THE
SOUTHWEST AND PARTS OF THE FLORIDA PENINSULA. CONFIDENCE IN BELOW-NORMAL MEAN
TEMPERATURES ALONG THE EASTERN SEABOARD IS LOW DUE TO AN EXPECTED WARM START TO
THE PERIOD, AND ALSO THE POSSIBILITY OF THE SOUTHEASTERN RIDGE BEING STRONGER
THAN THE ENSEMBLE MEANS INDICATES. A STRONG SOUTHEASTERN RIDGE WOULD FORCE THE
MID-CONTINENTAL TROUGH TO THE WEST OF THE POSITION PREDICTED BY THE ENSEMBLE
MEANS. THIS POSSIBILITY IS SUGGESTED BY BOTH THE 00Z AND 06Z GFS DETERMINISTIC
RUNS, AND ALSO IS FAVORED BY TELECONNECTIONS BASED ON A POSITIVE 500-HPA
ANOMALY CENTER NEAR 51N, 141W. THIS ALSO LOWERS CONFIDENCE IN THE TEMPERATURE
PREDICTION WEST OF THE ROCKY MOUNTAINS. ABOVE-NORMAL TEMPERATURES ARE FAVORED
FOR MOST OF ALASKA UNDER THE EXPECTED UPPER LEVEL RIDGE.

THE BROAD TROUGH EXPECTED OVER THE CENTRAL CONUS IS EXPECTED TO ELEVATE CHANCES
FOR NEAR TO ABOVE-MEDIAN PRECIPITATION AMOUNTS FOR MUCH OF THE EASTERN PART OF
THE COUNTRY. BELOW-MEDIAN PRECIPITATION IS FAVORED FOR MUCH OF THE SOUTHWESTERN
CONUS AND THE COASTAL PORTIONS OF THE PACIFIC NORTHWEST WHICH ARE EXPECTED TO
BE TO THE WEST OF THE MEAN TROUGH AXIS. MODELS INDICATE ABOVE-MEDIAN
PRECIPITATION FOR THE NORTHERN ROCKIES, ALTHOUGH CONFIDENCE IS NOT HIGH AND
ELEVATED CHANCES ARE RESTRICTED TO A FAIRLY NARROW BAND, REFLECTING SHORT WAVES
MOVING SOUTHWARD IN THE MEAN NORTHWESTERLY FLOW ALOFT. BELOW MEDIAN
PRECIPITATION IS FAVORED FOR EASTERN ALASKA, WITH ABOVE-MEDIAN PRECIPITATION
FAVORED IN THE WEST, REFLECTING THE RIDGE AXIS EXPECTED IN THE CENTRAL PART OF
THE STATE DURING THE PERIOD.

TODAY'S OFFICIAL 500-HPA BLEND CONSISTS OF 10 PERCENT OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8...20 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8...40 PERCENT OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON
DAY 8...AND 30 PERCENT OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8.

MODEL OF THE DAY: TODAY'S 00Z ECMWF ENSEMBLE MEAN

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS.

[TexasBreeze]

We shall see if the coldest of the airmass stays off to the east like they usually do when the polar vortex sends the air south, or if the trough sends it down the great plains more towards Texas...

[ticka1]

what time frame is this suppose to happen?

[MontgomeryCoWx]

what time frame is this suppose to happen?

Next week starting on Sunday with initial shot of cold then followed up by another soon after

[MontgomeryCoWx]

I'm hoping for a bit stronger SE ridge to send it more south

[srainhoutx]

Not a lot of changes overnight via the various operational/ensemble guidance. The next cold front arrives late New Years Day into Thursday with cloudy/cool conditions remaining entrenched across most of our Region. Some slight moderation this weekend before the next front arrives late Sunday into Monday. There may be a chance of rain and snow mixing across N Texas Saturday night into early Sunday, but more likely N of the Red River Valley. There is about a 24 hour timing spread via the models with the Euro being faster -vs- the GFS. Typically the faster solution is more correct with cold dense air draining S, so think the Euro has the timing somewhat right. Next Tuesday into Wednesday could be very cold offering the coldest air of the season...so far.

The coldest air still looks to be to our NE, but that will make little difference because it looks to be very chilly here in our Region as well. The cold looks to linger well into the mid January time frame with multiple short wave/upper air disturbances in the northerly flow dropping S and bringing re enforcing cold fronts and precip chances every few days with a progressive pattern of a parade of storms rotating around the Polar Vortex and a strong Gulf of Alaska High Pressure Ridge holding steady allowing multiple 1050-1060mb Arctic High pressure cells to drop into the Inter Mountain West and Plains. It may be time to escape to the S Pacific or the Florida Keys for those looking for warmer weather.

[djjordan]

Even the chilly air we have now is bone chilling to me lately. It's already been a cooler winter and from the looks of it January may be even colder.

Haven't been on the forum much lately but Happy New Year to all of you on the Weather Board. Keep up the great discussions.

[tireman4]

Happy New Year to all who visit, contribute and learn from this board. You all are very dear to this place and let us make 2014 a great year.

[srainhoutx]

I'd keep an eye on the early to mid next week time frame. The 06Z GFS suggested some wintry mischief potential across a lot of Texas into Louisiana after the cold air arrives.

[sambucol]

I'd keep an eye on the early to mid next week time frame. The 06Z GFS suggested some wintry mischief potential across a lot of Texas into Louisiana after the cold air arrives.

Does that include our area all the way to the coast?

[Ptarmigan]

I'd keep an eye on the early to mid next week time frame. The 06Z GFS suggested some wintry mischief potential across a lot of Texas into Louisiana after the cold air arrives.

Let's hope for some snow. Anyways, Happy New Years to everyone here! 2014 could be interesting in the weather world.

[Portastorm]

FWIW, the 12z GFS is showing some wintry "mischief" for portions of West Central and North Texas in about a week's time.

[srainhoutx]

There are some significant changes via the 12Z Euro today. That model now suggests the much colder anomalies both in the temperatures expected and the placement of the mean trough axis is further W and S by hour 144.