February: Calm Weather To End The Month

[srainhoutx]

The 12Z Euro gives weekend rain, the 0Z Euro takes away...

http://www.ecmwf.int/products/forecasts ... !chart.gif

Look for possible WSR as two camps (Euro/GFS~vs~UKMet/Canadian) and run to run flip flopping lead to little confidence in any one solution at this time.

[wxman57]

None of the models indicates any cold air building over western Canada for the next 10-15 days. Without that, it's more of the same across Texas.

[weatherguy425]

Well the GFS; at least the operational, has been showing showing a sharp cooling trend across all of Canada in the longer range. The GFS has also been hinting at some of this air heading southward, or at least building westward. Now, I'm know its in LaLa land, the pattern has been giving models fits, and the air isn't all the far below normal for Canada ( at least western Canada) but it's better than what our source region looks like now...

[srainhoutx]

Hello +PNA...can we say off the charts...

[srainhoutx]

Not much confidence in the guidance so far for later in the week. The flip flopping from run to run suggests just how difficult that Pacific pattern is and when we see a transition is occurring with a West Coast Ridge (+PNA/-EPO) and tropical forcing from the MJO. Expect those flip flops to continue until the pattern develops and we see possible Winter RECON missions S of Alaska.

[wxman57]

With that ridge over the western U.S. that the Euro & GFS are building late this week, the Euro indicates the possibility of, you ready? A LIGHT FREEZE in northern Houston next Monday! Fortunately, the GFS has a low of 55 in Houston next Monday with that big shot of Arctic air. But the 12Z GFS has us into the 30s the weekend after next. Don't know how I'll tolerate such extreme cold next week.

All sarcasm aside, it's hard to get very cold down here without cold air up north in Canada and no snow pack across the Plains.

Meanwhile, we're all bundled up for our bike ride this afternoon. About 40 miles in sub-70 degree frigid air. Hope we survive the cold.

[srainhoutx]

The 12Z Euro has trended slower with the trough and the upper air disturbance for later in the week. HPC has tasked WSR (Winter RECON mission for the Pacific that include C-130 flights from Alaska and a possible G-IV mission from HI. We should see guidance settle on a sensible solution with that additional data in the days ahead.

WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
0115 PM EST SUN 29 JANUARY 2012
SUBJECT: WINTER STORM PLAN OF THE DAY (WSPOD)
VALID 30/1100Z TO 31/1100Z JANUARY 2012
WSPOD NUMBER.....11-060

I. ATLANTIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.

II. PACIFIC REQUIREMENTS
1. FLIGHT ONE -- TEAL 72
A. P54/ DROP 8 (45.0N 166.0W)/ 31/0000Z
B. AFXXX 08WSC TRACK54
C. 30/1830Z
D. 17 DROPS AS PUBLISHED ON TRACK
E. AS HIGH AS POSSIBLE/ 31/0600Z

2. SUCCEEDING DAY OUTLOOK:
A. POSSIBLE TEAL C-130J MISSION FOR
P56/ DROP 9 (44.3N 151.0W)/ 01/0000Z.
B. POSSIBLE NOAA G-IV MISSION FOR
P56/ DROP 9 (44.3N 151.0W)/ 01/1200Z.

[Portastorm]

With that ridge over the western U.S. that the Euro & GFS are building late this week, the Euro indicates the possibility of, you ready? A LIGHT FREEZE in northern Houston next Monday! Fortunately, the GFS has a low of 55 in Houston next Monday with that big shot of Arctic air. But the 12Z GFS has us into the 30s the weekend after next. Don't know how I'll tolerate such extreme cold next week.

All sarcasm aside, it's hard to get very cold down here without cold air up north in Canada and no snow pack across the Plains.

Meanwhile, we're all bundled up for our bike ride this afternoon. About 40 miles in sub-70 degree frigid air. Hope we survive the cold.

Yeah but you know as well as we do (because you'd told us) that model reliability beyond five days right now is low. Alaska has below normal temps right ... while a lack of below normal temps in western Canada may be true at the moment, a change in the upper air pattern would quickly usher that Alaska air into western Canada and the Western US. That along with a predicted active MJO (octaves 7-8-1-) and all of a sudden, we *could* see very cold air in the source regions and snow cover across the Plains.

You'll pay for all of this winter sarcasm! Oh yes, you will pay ...

[srainhoutx]

The 12Z UKMET held and now suggests a cut off low with a deep trough developing across the eastern half of the US. The longer range Euro also suggests very chilly air settling S into the Plains with a +PNA/-EPO/-NAO regime becoming established.

[srainhoutx]

HPC Afternoon Final Update:

AFTN MODEL AND ENS GUIDANCE CONTINUES UNDERMINE ANY ALREADY LOW
CONFIDENCE IN ANY RELIABLE SOLUTION OVER MUCH OF CONUS AS
GFS/UKMET/CMC/ECMWF HAVE GONE BACK TO YESTERDAYS 12Z SOLUTIONS OF
LEAVING BEHIND SIGNIFICANT ENERGY IN SWRN CONUS WITH THE CMC/UKMET
AND ECMWF HAVING THE STRONGEST MID LEVELS AND AT THE SFC FORMING A
SFC LOW IN THE SRN PLAINS TO GLFMEX REGION THEN MOVING INTO THE
SOUTHEAST AND MID ATLC REGIONS. GFS WHILE LEAVING BEHIND MORE OF A
MID LEVEL LOW IN THAT REGION SHEARS IT OUT AND HAS THE DIGGING NRN
STREAM THE DOMINANT FEATURE. THIS RESULTS IN A NRN STREAM SHORTWVE
AND LOW REFORMING FROM THE OH VALLEY TO THE NC COAST BUT SHIFTING
EWD WELL OFFSHORE. THE VERY LARGE SPREAD OF SOLUTIONS AND
UNCERTAINTY AND A GREAT WEATHER AND SOCIAL POTENTIAL IMPACT IN
WHATEVER SOLUTION TURNS OUT TO BE CORRECT WARRANTS A WINTER STORM
PACIFIC RECON WHICH WILL BE FLOWN EARLY THIS WEEK. AFTN FINALS
WILL NOT BE CHANGED BASED ON THE RECENT 12Z RUNS. THERE IS
SIMILARITY TO YESTERDAYS 12Z RUNS WHICH QUICKLY CHANGED OVERNIGHT.

[texoz]

srain, can you decipher that stuff in bold just a bit?

Are they concerned about a major storm, or concerned that we're nearing end of winter with little on the horizon for snow pack in midwest/eastern US?

[Andrew]

srain, can you decipher that stuff in bold just a bit?

Are they concerned about a major storm, or concerned that we're nearing end of winter with little on the horizon for snow pack in midwest/eastern US?

Basically the models don't really know what is going on right now and as a result a plane will be flown out to try and get more data in the pacific for the models to digest. That will HOPEFULLY relieve some of the spread and the models can come to an agreement on a solution.

[texoz]

well, the NWS now has 20-30% rain chances (including t-storms) here in Austin Friday through Sunday. curious how that plays out.

[Ptarmigan]

Maybe Ptargiman has studied this, the synoptic set-up to the great 1899 Arctic outbreak, the one that froze shallow water in Galveston Bay and allowed people to collect stunned fish.

My understanding with the 1899 Freeze were series of cold blasts up to the big one. Here is an article about the freeze.
http://journals.ametsoc.org/doi/pdf/10. ... 2.0.CO%3B2

The big one came from a high pressure system that went over Montana. I could imagine that high pressure being really high over Alaska, probably over 1100 mb!

1899 Climate Pattern
ENSO
Neutral

NAO
Negative

AO
Unknown, probably negative since NAO was negative

PNA
Unknown

The 1899 Freeze is truly one of a kind. The closest are February 1895, December 1983, and December 1989. Also, the 1895 and 1899 occurred during a cooler phase.

[sambucol]

Drudge Report has an article on site that says Fairbanks, Alaska fell to 50 below causing small air carriers to cancel flights. Link is here: http://newsminer.com/view/full_story/17 ... left_top_1

Is this going to move down and possibly get some cold air down here?

[Portastorm]

well, the NWS now has 20-30% rain chances (including t-storms) here in Austin Friday through Sunday. curious how that plays out.

Yep. They're shotgunning the chance of pops due to some of the models showing a cutoff low to our west.

[Andrew]

00z GFS still says no freeze and is much more progressive and the latest cmc has trended slightly that way but the Euro still remains cold and even some chances of minor overriding precip but being so far out and without any model consensus it is hard to really choose who will be right. I will talk about it more tomorrow but right now I am tired!

[srainhoutx]

The models are clueless right now. Check back on Tueasday after WSR (Winter Storm RECON) data begins to arrive for any sensible solution regarding later this week...

[srainhoutx]

The models are clueless right now. Check back on Tueasday after WSR (Winter Storm RECON) data begins to arrive for any sensible solution regarding later this week...

Extra data points help, but I doubt we'll see unanimous solutions between models that have different number of terms in the transform equations (and different grid scale resolutions), different physics packages, and different schemes for initializing data before they begin running, The Euro comes later than the GFS not just because of better grid resolution, but because of a more complicated initialization scheme. Every now and then people way smarter than I start tossing around words like "4DVAR" or "Ensemble K-F Filters" or the such, and one realizes that 1) w/o a met degree, you can't stop it, you can only hope to hold it under 100 yards and 2) there is more to forecast models than meets the eye.

But it can't hurt. Extra Pacific data points ingested into the model. And, the differences between the GFS, Canadian and Euro seem to be shrinking somewhat already.

The Euro for Friday is not yet screaming "severe storms" from the mountain top, with CAPE values Friday afternoon per Euro just below 500 J/Kg, and low-mid level winds just a hare lighter than I'd like to see, but almost 120 hours out, it is worth paying attention to.

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
847 AM EST MON JAN 30 2012

VALID 12Z FRI FEB 03 2012 - 12Z MON FEB 06 2012


PRELIMINARY UPDATE...

USED THE 00Z/30 DETERMINISTIC ECMWF TO UPDATE THE PRELIMINARY
FRONTS AND PRESSURES FOR DAYS 3 AND 4...THEN SWITCHED TO THE
00Z/30 ECENS MEAN FOR DAYS 5 THROUGH 7. FORECAST CONFIDENCE DROPS
PRECIPITOUSLY AFTER DAY 4...WITH A DIZZYING ARRAY OF MODEL
SOLUTIONS FOR THE FLOW ACROSS CENTRAL NORTH AMERICA AT THAT RANGE.
THE CULPRIT...A FAMILIAR ONE THIS COLD SEASON...IS A PRONOUNCED
SPLIT IN THE JET...WITH THE DOMINANCE OF ONE STREAM VERSUS ANOTHER
RENDERING THE SORTING OF INDIVIDUAL SHORTWAVES AND THEIR POTENTIAL
INTERACTIONS MOOT. ELECTED TO RELY ON THE ECENS MEAN OVER THE
GEFS MEAN FOR THE MOST UNCERTAIN TIME FRAME...WITH A GLIMMER OF
HOPE LYING IN THE CROSS-MODEL SUPPORT WITH THAT MEAN FROM THE
00Z/30 DETERMINISTIC GFS. THE ECMWF LOOKED FINE FOR THE FIRST TWO
DAYS...CLOSELY CORRELATED WITH THE ECENS MEAN.

[srainhoutx]

For those interested, here are the flight plots for WSR (Winter Storm RECON)...