January: Increasing Clouds/Rain & Warmer To End Month

[srainhoutx]

This is a true blocking pattern via the 12Z Euro. That long range 240 hour chart shows a +PNA/-AO/-EPO/-NAO pattern developing. We will see...

01062012 12Z Euro Geopotential3250032hPa32and32Temperature32at3285032hPa_North32America_240.gif

01062012 12Z Euro 12zECMWF500mbHeightAnomalyNA240.gif

01062012 12Z Euro 12zecmwfhourly850mbTempAnomalyNA240.gif

[MontgomeryCoWx]

Hell yeah, thats a true omega block in Gulf of Alaska.

[MontgomeryCoWx]

I can tell who our Severe Weather Geek is here on the forums...

[MontgomeryCoWx]

Can anyone tell me how to access Jeff Lindner's emails or does he have his own listserv that you have to request to be on.

[MontgomeryCoWx]

I have a picture somewhere of the Kyle F ield Snow Picture... My wife had it on her computer.

[MontgomeryCoWx]

Here's the snow from 2010

http://www.youtube.com/watch?v=me9O6WxKV3s

I think they got ~2-3 inches that day.

[srainhoutx]

The HPC Final afternoon update is in and basically says to toss the 12Z GFS out...

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
208 PM EST FRI JAN 06 2012

VALID 12Z MON JAN 09 2012 - 12Z FRI JAN 13 2012

A STRONG POSITIVE MID-LEVEL HEIGHT ANOMALY OVER THE NORTHERN
ATLANTIC CENTERED AROUND DAY 8 TELECONNECTS REASONABLY WELL WITH A
PERSISTENT LONGWAVE TROUGH AND LONGWAVE RIDGE OVER THE GREAT LAKES
AND PACIFIC NORTHWEST RESPECTIVELY THROUGH THE MEDIUM RANGE
PERIOD. THIS ANOMALY WEAKENS QUICKLY AND THE DOMINENT ONE IS
UPSTREAM NEAR THE ALEAUTIANS. THIS TELECONNECTS AT THE D+8-11 TIME
RANGE TO MORE OF A TROF ALONG THE PACIFIC NORTHWEST AND A BROAD
TROF ALONG THE GULF COAST INTO THE SOUTHEAST BUT WITH ABOVE AVG
HTS. THIS KEEPS UP THE RECENT PATTERN OF HIGH AMPLITUDE CHANGES
MODIFYING RAPIDLY TO A MORE MODERATE FLOW REGIME.

THE LATEST DETERMINISTIC AND ENSEMBLE GUIDANCE ARE CONSISTENT WITH
THIS PATTERN AS WELL BUT DIFFER UPON THE DETAILS...PARTICULARLY
BEYOND DAY 4 WHEN THE SOLUTION SPREAD BECOMES QUITE LARGE AS THE
NEXT LONGWAVE TROUGH BEGINS TO AMPLIFY IN THE LEE OF THE CANADIAN
ROCKIES. THUS...CONFIDENCE IN THE PRECISE DETAILS OF THE MODEL
SOLUTIONS BECOMES LOW FROM THIS POINT FORWARD. THE MAIN
DIFFERENCES TO RESOLVE INVOLVE THE TIMING/STRENGTH OF THE UPPER
LOW CROSSING THE GULF COAST AROUND DAY 5/WED...AND THE SUBSEQUENT
TIMING/STRENGTH OF A DIGGING TROUGH OVER THE CENTRAL CONUS.
ALTHOUGH THE 00Z GFS/ECMWF ARE REASONABLY CLOSE TO EACH OTHER
THROUGH THE ENTIRE PERIOD...ENSEMBLE SPAGHETTI DIAGRAMS OF RECENT
CYCLES SHOW MUCH MORE SOLUTION SPREAD...WITH THE 00Z PARALLEL GEFS
MEAN ABOUT MIDWAY BETWEEN THE 00Z OPERATIONAL GEFS MEAN AND 12Z
ECMWF ENSEMBLE MEAN. THUS...GIVEN THE GROWING UNCERTAINTY BEYOND
DAY 4 AND THE DESIRE TO MAINTAIN AT LEAST SOME DETERMINISTIC
DETAIL IN THE UPCOMING DAY 3-7 SURFACE PROGS...THE PREFERENCE IS
FOR A 4-WAY MODEL BLEND INVOLVING 20 PERCENT EACH 00Z GFS/ECMWF
AND 30 PERCENT EACH GEFS MEAN/ECMWF ENSEMBLE MEAN...WHICH IS
SUPPORTED BY THE PARALLEL GEFS MEAN.

UPDATED MORNING PRELIMS USE THE AVAILABLE 00Z ECMWF ENS MEAN AND
LAGGED AVERAGE FORECASTS WHICH CHANGE THE ABOVE MENTIONED
PREFERRED SOLUTIONS BY DAYS 6 AND 7 TO THE ECMWF ENS MEAN OVER
CONUS. THIS IS A SOMEWHAT SLOWER COLD AIR INTRUSION INTO CENTRAL
AND ERN CONUS DAYS 6 AND 7 AND VERY LIMITED FRONTAL WAVE
DEVELOPMENT ACROSS THE GULFMEX.

GFS LOOKS SPURIOUS DROPING BACK ITS FORMER OUTSIDE SLIDER
SHORTWAVE INTO THE PACIFIC DAYS 4 AND 5 AS A CUTOFF LOW THEN
BRINGING IT BACK FOR A LANDING IN THE PAC NW DAY 8. PREFER THE
COASTAL OR JUST INSIDE SLIDER ROUTE OF 00Z/12Z ECMWF AND 12Z CMC.
DAY7-8 SHORTWAVE APPROACH INTO THE PAC NW AND NRN ROCKIES BRINGING
ANOTHER CHANCE AT PCPN INTO THEPAC NORTHWEST AND NRN ROCKIES.

[MontgomeryCoWx]

I can tell who our Severe Weather Geek is here on the forums...

I'd say its more satisfying than being a SETX snow lover, but actually, the last 3 1/2 years, it hasn't been.

I'd say you are right, but I'm more for the unique weather events... you know Gulf Coast Snows/Ice Storms, noreasters, Major Hurricanes actually making landfall in Texas....

The tornado outbreak in Alabama was probably my most eye opening experience.

[MontgomeryCoWx]

So HPC is leaning toward the Canadian output????

[redneckweather]

As far as getting snow down here in Southeast Texas....I believe from past events snow occurred with more of a deep cold Canadian type air mass rather than a cold arctic air mass because they seem to be shallower in nature. Most of our ice storms down here in the deep south seem to come from arctic air masses. Correct?

Also, to get snow down here, we don't have to have a snow pack off to our north. As long as the air is deep enough with moisture present. Not sure how shallow or deep the models are showing this arctic air mass to be?

[srainhoutx]

As far as getting snow down here in Southeast Texas....I believe from past events snow occurred with more of a deep cold Canadian type air mass rather than a cold arctic air mass because they seem to be shallower in nature. Most of our ice storms down here in the deep south seem to come from arctic air masses. Correct?

Also, to get snow down here, we don't have to have a snow pack off to our north. As long as the air is deep enough with moisture present. Not sure how shallow or deep the models are showing this arctic air mass to be?

That is correct. Our snow events throughout most of the years have been Polar/Canadian air masses. We did get snow in 89 with that Arctic outbreak as well as some light snow in 83, but it didn't amount to much. Our events here tend to be upper low and coastal low development with over running precip. The closer the U/L is to us, the better we seem to do, accumulation wise. What does help is snow cover to our N which is lacking right now, but with the split flow and projected upper air pattern, that appears to be changing with time. Jeff just sent out an e-mail, so we'll focus on the events of Sunday-Tuesday for the time being...


Warm and humid conditions prevail through the weekend before the next storm system and colder weather arrives next week.

Weak washing out frontal boundary over the coastal counties and an eastward moving upper air disturbance is creating a few showers near the coast early this afternoon. Bigger problem in the next 48 hours will be formation of dense sea fog as near shore dewpoints exceed water temperatures along with light winds. Sea fog will be likely tonight through Sunday night near/along the coast and in the bays and spreading inland each evening. Visibilities of less than ½ of a mile are likely in the sea fog bank.

Next weak front will pass across the region on Sunday and this will begin a change for the region by early next week. While this happens a potent upper level storm will dig into position over the SW US with downstream sub-tropical jet coring across TX by late Sunday. Moisture will remain high over the area and increase by late Sunday while surface boundary stalling near the coast/just offshore begins to lift slowly northward as a warm front. Combination of increasing lift and favorable jet dynamics points to widespread rain developing late Sunday into Monday with some heavy at times especially near the northward lifting warm front. Models are typically too fast lifting such boundaries northward when rainfall is in progress and would like to hold the boundary closer to the coast/US 59 corridor and this may be the region where some hefty rainfall totals may accumulate on Monday.

Next and stronger front will cross the region Monday afternoon, but the upper level storm/trough remains west of the region for a period helping to induce a period of moisture being pulled up and over the frontal slope. Additionally the surface and upper level storms will intensify while crossing TX leading to some potential for wrap around rainfall in the colder air especially north of HWY 105 into Tuesday morning. Lack of cold air across the nation will keep everything liquid with this storm system.

Fairly decent period of moisture advection into the region will support some heavy rainfall potential from Sunday PM –Monday PM across the region. While too early to pin point exactly where the heavy rains will fall, warm frontal boundary position is usually a good indicator for such potential. Widespread 1-2 inches appear likely with isolated amounts of 2.5-3.5 inches especially where cell training develops.

It will be warm and muggy through the weekend and then turning colder Monday, or at least back toward January temperatures of highs in the upper 50’s and lows in the 30’s by Tuesday.

[Ptarmigan]

As far as getting snow down here in Southeast Texas....I believe from past events snow occurred with more of a deep cold Canadian type air mass rather than a cold arctic air mass because they seem to be shallower in nature. Most of our ice storms down here in the deep south seem to come from arctic air masses. Correct?

Also, to get snow down here, we don't have to have a snow pack off to our north. As long as the air is deep enough with moisture present. Not sure how shallow or deep the models are showing this arctic air mass to be?

The February 1989 freeze was a shallow freeze, despite being below freezing for 5 days. There was frozen rain that time. It also occurred during a La Nina.

February 1989
ENSO
La Nina

PDO
Cool (Negative)

NAO
3.2
Positive

AO
3.279
Positive

PNA
-1.06
Negative

[srainhoutx]

Updated QPF forecast from the HPC has been issued...

[MontgomeryCoWx]

2-3 inches in Montgomery County!

I dig it.

[Ounce]

UPDATED MORNING PRELIMS USE THE AVAILABLE 00Z ECMWF ENS MEAN AND
LAGGED AVERAGE FORECASTS WHICH CHANGE THE ABOVE MENTIONED
PREFERRED SOLUTIONS BY DAYS 6 AND 7 TO THE ECMWF ENS MEAN OVER
CONUS. THIS IS A SOMEWHAT SLOWER COLD AIR INTRUSION INTO CENTRAL
AND ERN CONUS DAYS 6 AND 7 AND VERY LIMITED FRONTAL WAVE
DEVELOPMENT ACROSS THE GULFMEX.

Would this happen to mean the cold air arrival would be later than previously modeled? I'm looking for lower than seasonal temperatures for the Marthon on the 15th, which would end up being day 9. Thanks.

[MontgomeryCoWx]

I'm seeing this for precip totals.... wow

[JackCruz]

Snow on the 18th will be nice! Really nice...it doesn't have to stick...just to see it fall would be nice..

[srainhoutx]

Winter Storm Watches have been hoisted for the higher terrain of New Mexico while Special Weather Statements for wintry mischief are out for El Paso, Midland/Odessa and Amarillo. The 00Z NAM is suggesting showers/storms beginning Sunday in Central Texas and spreading W to E. Also noteworthy is the suggestion of yet another upper low diving S along the West Coast next Tuesday as another strong northern stream storm develops in Canada and a potent front begin to trek S into the Plains. Interesting days ahead folks. Enjoy the warm and dry weather while it lasts...

[biggerbyte]

Amen to that. Things are about to get whacked.

[srainhoutx]

Tonight version of the 00Z GFS remian consistant in the near term with rain/storms for Sunday inot Monday night. Then that model has flipped from suggesting a retrograding W upper low into the Pacific to stalling that feature near the Baja Region for several days. The Canadian suggests otherwise in the medium range and drops a potent front and full latitude trough develops fron N to S in the Plains similar to wht we saw on the 12Z run with precip falling behind that front as the upper trough treks E across Texas and a coastal low develops near the Lowe/Middle TX Coast.