jasons wrote:Joe mentions 1983/1989 or 1899 every year. I started reading him back in 99/2000 and even back then, he would bring out the 'ghost of 1899' every time he saw cross polar flow being setup. The chances of us seeing such an extreme event in any given season is extremely low.
Oh, I totally agree Jason. We see people every winter roll out the 1983 or 1989 comparisons, or even the 1899 one. It's hyperbole. What we have seen though from the model analogs is suggestion that the pattern in the days ahead is similar to December 1983. People aren't just making it up ... the actual model analogs show that month/year along with comparisons to other periods where the weather patterns match closely.
I'm skeptical myself of an 83 or 89 redux ... but next weekend, a cold front -- similar to or slightly stronger than what we just saw -- is a very real possibility.
Belmer wrote:I was more talking about the 00Z GFS in whole, not specifically here in Houston.
I'm assuming you mean the portion of the 0z GFS operational run which showed two-thirds of Texas encased in snow and ice around the middle of December? Yes ... I'd say that is for amusement purposes only!
The 00Z GEFS anomalies suggest a lot of shades blue across a large potion of North America. There may well be a storm system tracking out of the Great Basin into the Plains as the Arctic boundary drops S into the Plains next weekend. There is already some 'chatter' to our N in Oklahoma and the Panhandle as well as New Mexico of more wintry mischief. I just do not see that air mass stopping at the Red River by a barbed wire fence as some of the operational guidance suggests.
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Portastorm wrote:Nice-looking meteograms, wxman57! I highly doubt they'll verify but nice-looking nevertheless.
No sir, one operational run of a somewhat poorly performing computer model will not save you from the coming winter apocalypse. Teleconnections and model ensembles point to a colder, stormier southeast Texas than what this shows.
I agree, that warming trend next week will probably continue through January.
My good friend, wxman57, I would like you to do a meteogram for IAH or AUS from the 12z GFS coming in now ... oh, let's look at temperatures starting around 12z on 12/9. Heh ... heh ...
It certainly appears that old stepping down pattern where each intrusion of colder air will be stronger than the one before. What raises an eyebrow is the amount of snow cover accumulating for a rather long period as multiple storm systems and abundant moisture spreads across the Plains meaning less air mass modification as time goes on.
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1059 AM EST FRI NOV 29 2013
VALID 12Z MON DEC 02 2013 - 12Z FRI DEC 06 2013
...BITTER COLD TO INVADE THE WESTERN HALF OF THE NATION THIS
FORECAST PERIOD...
...OVERVIEW...
ARCTIC SURGE AND AMPLIFYING UPPER-LEVEL FLOW FROM THE EASTERN
PACIFIC TO THE INTERMOUNTAIN WEST WILL BE THE PREVAILING WEATHER
THEMES THIS MEDIUM RANGE PACKAGE ACROSS THE WESTERN HALF OF THE
CONTINENTAL UNITED STATES. IN THE EAST AND SOUTHEAST...THE MAIN
FORECAST CHALLENGE WILL BE TO DETERMINE THE OUTCOME IN THE WESTERN
ATLANTIC--OF SOUTHERN STREAM ENERGY ORIGINATING IN SOUTHERN AND
BAJA CALIFORNIA.
...MODEL PREFERENCES AND UNCERTAINTY ASSESSMENT...
ASPECTS OF THE DETERMINISTIC 29/00Z GFS/ECMWF AND THEIR RESPECTIVE
MEANS SHOULD HANDLE THE LARGER-SCALE WEATHER FEATURES THIS MEDIUM
RANGE FORECAST PERIOD. THAT INCLUDES THE PROGRESSION OF A MASSIVE
AND BITTERLY-COLD ARCTIC INTRUSION INTO THE LOWER 48 ON LATE
MONDAY INTO TUESDAY.
THE BIGGEST FORECAST CHALLENGE IS TIMING THE SOUTHWARD RELEASE OF
THE AIRMASS THROUGH THE VERY COMPLEX TERRAIN OF THE ROCKIES AND
GREAT BASIN. TIED TO THIS RELEASE...A SERIES OF MID-LEVEL
SHORTWAVES WILL ROTATE THROUGH THE BASE OF THE BROAD-SCALE
UPPER-LEVEL TROUGH AND PROVIDE SOME OVER RUNNING MOISTURE THAT
WILL INITIALLY MODIFY THE LEADING EDGE OF THE BOUNDARY. THIS SETS
UP A LONG-DURATION WINTER WEATHER EVENT FOR A LARGE PORTION OF THE
WEST...INCLUDING MONTANA...IDAHO PORTIONS OF NORTHERN
UTAH-NORTHERN COLORADO...WYOMING AND THE DAKOTAS.
WPC MANUALLY ADJUSTED THE SURFACE GRAPHICS TO FIT TERRAIN AND
INCLUDED A 40+ MILLIBAR SURFACE GRADIENT BETWEEN NORTHWEST MONTANA
AND SOUTHWEST KANSAS FOR DAYS 4-5. THIS IMPLIES STRONG
WIND...COUPLED WITH SIGNIFICANT SNOWFALL.
ALOFT...THE GEFS...NAEFS AND ECMWF ENSEMBLE GUIDANCE PREFER TO
MAINTAIN A DEEP TROUGH AXIS OVER THE DESERT SOUTHWEST INVOF 110W
THROUGH THE END OF THIS MEDIUM RANGE PERIOD...BUT HAVE DIFFERENT
SOLUTIONS AND CONCLUSIONS DOWNSTREAM WITH AN 'INITIAL SHORTWAVE'
EXITING THE UPPER-LEVEL SYSTEM AS EARLY AS DAY 4 (INTO THE
NORTHERN HIGH PLAINS).
THE 29/00Z DETERMINISTIC CYCLE OFFERED A MIXED BAG OF
RESULTS...WITH THE 29/00Z CANADIAN BEGINNING TO TAKE A FASTER AND
MORE SOUTHERLY SOLUTION OVER THE PLAINS BY 4/00Z WITH THE ENERGY
TRACKING OVER THE BLACK HILLS AND QUICKLY RACING IT EASTWARD INTO
NEBRASKA/IOWA BY 4/18Z.
RECOMMEND A BLEND OF THE DETERMINISTIC 29/00Z ECMWF/GFS TO SORT
OUT SOME OF THE SMALLER SCALE DETAILS SURROUNDING THE DIGGING
UPPER-LEVEL TROUGH WHICH PEELS SLOWLY SOUTHWARD AND DRAW THE
ARCTIC AIRMASS WEST OF THE CONTINENTAL DIVIDE AND DEEP WITHIN THE
GREAT BASIN AND DESERT SOUTHWEST DURING THE LATTER HALF OF THIS
PACKAGE. BOTH HAVE A 'LEAD' SHORTWAVE EJECTING NORTHEASTWARD IN
THE DAKOTAS AROUND 5/12Z...BUT MAINTAIN THE BULK OF THE
ENERGY--AND MORE IMPORTANTLY--COLD POOL ALOFT OVER IDAHO (THE
ECMWF) AND EASTERN NEVADA (THE GFS) WHEN THE CANADIAN HAS THE LEAD
SHORTWAVE...AND MUCH OF THE UPPER-LEVEL TROUGH RACING TOWARDS
SOUTHERN ONTARIO.
...SENSIBLE WEATHER HIGHLIGHTS...
CONFIDENCE IS RISING FOR TEMPERATURES RANGING FROM 15F TO 25-30+ F
BELOW NORMAL ACROSS THE WESTERN STATES AND NORTHERN PLAINS.
VOJTESAK
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Portastorm wrote:My good friend, wxman57, I would like you to do a meteogram for IAH or AUS from the 12z GFS coming in now ... oh, let's look at temperatures starting around 12z on 12/9. Heh ... heh ...
Only 37 at 12Z on the 9th at IAH. 26-27 next 2 days but a quick warm-up.
Uh huh ... and that is a little different than the last GFS-based meteogram you showed. Then again it is the GFS where any one particular operational run could suggest just about anything.
Point being ... Old Man Winter is coming back next weekend. For Houston. And Austin. And much of Texas. And he seems a bit cranky too.
[quote="Ed Mahmoud"
Long range GFS within a few degrees of freezing, and you're automatically ruling out freezing/frozen? Multiple runs (including today's 12Z) beyond the resolution lobotomy below 40F with precip, and I'm staying 1/32nd glass full optimistic. Now, if it is the models are saying 3 or 4C the day before the event, optimism could drop below 1/64th.
Not a trained, highly paid professional, and I am a silver lining optimist, but I'm not giving up.[/quote]
Of course not. There was talk of 1983 and 1989 and I said I don't see anything to indicate THAT cold anywhere around here.
wxman57 wrote:I see nothing in last night's GFS to indicate any frozen precip or very cold temps here through 15 days. I do see temps near 80 next week and then a light freeze next weekend (no precip).
Long range GFS within a few degrees of freezing, and you're automatically ruling out freezing/frozen? Multiple runs (including today's 12Z) beyond the resolution lobotomy below 40F with precip, and I'm staying 1/32nd glass full optimistic. Now, if it is the models are saying 3 or 4C the day before the event, optimism could drop below 1/64th.
Not a trained, highly paid professional, and I am a silver lining optimist, but I'm not giving up.
There will be a lot of very cold air building into the NW and N US this week, not sure the GFS is fully understanding that. Most models want to keep the heart of this bitter cold locked in the NW US, but once in the plains I am not sure if the SW flow aloft will be enough to prevent at least some of it from bleeding southward. Still not looking at anything extreme at the moment, but think the GFS is too warm especially if the air mass is shallow and overrun.
The Day 11+ analogs continue to point toward a December 2008 scenario which brought tied the earliest accumulating snow to Houston every recorded dating back to 1944 to be broken the following year in early December 2009. It will be interesting to see if we see a similar pattern develop that brought a cold core 5H low across New Mexico and Texas embedded within a noisy sub tropical jet and the Arctic air appears to come in the form of several short waves diving S into the Great Basin and the Desert SW well into the medium/longer range period. We will see.
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Just as interesting to me (as how cold we actually get) is the duration of this cold spell. Looking at a week+ of cold air across the lower 48. Pattern just keeps wanting to re-load out west. Wouldn't be surprised if I (in Lubbock) saw a night, or two, of single digits out of this - first 'non snow-pack' induced low temp below 10° in a couple of years.
Brrr...a full latitude trough even during the day 10 time frame with an Arctic Outbreak fully underway across the Inter Mountain West and Plains tends to raise an eyebrow.
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I wouldn't get too hung up on the model depiction and focus more on the pattern and potential. What will we be dealing with? We'll be dealing with a shallow Arctic airmass overhead. A snowpack cover deeper and wider in scope than what we saw with last weekend's cold front, thus, the air should be colder and stay longer. A southwest flow which looks to remain "active" after cold frontal passage with overrunning precip developing later in the weekend.
All of this means the potential clearly exists for a winter storm in parts of Texas next weekend. The ingredients will be there but, as always, timing will be of the utmost importance.
