Texas Winter 2012-2013

[Palmer divide shadow]

Jan 07 was prob the coldest the west has seen in 20 years not including feb 11.

[Ntxw]

Little update on AO forecasting. We know the SSW splits the vortex and generates cold, but another element is also sending the warming down closer to us (top-down event). At 10hpa it's hot and above, but closer to troposphere it hasn't propagated. This is probably why the -AO hasn't yet tanked. Posts ago I said I believe the AO will tank near the end of the month, guidance does support that notion once the warming reaches 100hpa and lower, this will promote ridging at the lower levels over the EPO/WPO/AO region.



Trending that way for the GFS

[Cyclenall]

I was off here for 1 week and I don't know how things transpired but as of right now where is the PV most likely to set up in NA? If there was another big discussion on the overall atmosphere in North America (and world) and long range, do you know what pages it was on? I would like to read it. 40 pages is a lot to go through so I rather not look . The models are now in range for the time period where the SSW event would translate to ground truth cold.

As with most complete warming events (not certain for all cases but most strong ones) the vortex was split. The troposphere reflections left one in Hudson Bay and one in North-Central Russia. They remain there until the upper strat cools and re-consolidates <- this won't likely happen this winter since the warming lasted so long and continues so the twin vortexes will likely remain in place. Next week high pressure will help bump the Canadian one east/se through interior Ontario and Quebec before reforming around the bay.

*Image*

So would that be similar to February 2007 because that was really one of the biggest snow events for us. I see some analogues showing Feb 2007.

OK, what is JB seeing in the EURO Ensembles to cause him to tweet that the 1st-15th will be the coldest we've seen since 07. The 12z Ensembles only go out to the 29th. The pattern at that time looks somewhat similar to the one we've been in for the past couple weeks. Any thoughts.
12z EURO Ensembles:
http://raleighwx.americanwx.com/models/ ... yNA240.gif

I like that, positive heights over me. Good set-up to keep everyone happy.

[Ntxw]

So would that be similar to February 2007 because that was really one of the biggest snow events for us. I see some analogues showing Feb 2007.

That is a very good comparison for E/SE Canada, very similar temps and the Lakes are unfrozen.

[Cyclenall]

So would that be similar to February 2007 because that was really one of the biggest snow events for us. I see some analogues showing Feb 2007.

That is a very good comparison for E/SE Canada, very similar temps and the Lakes are unfrozen.

Oh boy, this could be it . My forecast is already showing the most snow and coldest temperatures in years. 50 cm in the next 6 days as the max with blowing snow...

The Lakes are not just unfrozen, they are very very warm. I know there was as study that disproves any link to warmer lake surface temps. and LES but I can't help to think...

[Ntxw]

The Lakes are not just unfrozen, they are very very warm. I know there was as study that disproves any link to warmer lake surface temps. and LES but I can't help to think...

They will cool pretty quick with such an air mass, I think the key to big lake effect snows will be the persistent arctic jet (you see constant stream of 5h vorticity). For SE Ontario a westerly wind component is the best set up for best squalls from Huron which is forecasted by the models with that streaming 5h. I'm no expert on LES though, just a wild guess!

[natlib]

Larry Cosgrove has encouraging words for winter weather lovers in texas come the first week of Feb.

[SaskatchewanScreamer]

So would that be similar to February 2007 because that was really one of the biggest snow events for us. I see some analogues showing Feb 2007.

That is a very good comparison for E/SE Canada, very similar temps and the Lakes are unfrozen.

Oh boy, this could be it . My forecast is already showing the most snow and coldest temperatures in years. 50 cm in the next 6 days as the max with blowing snow...

The Lakes are not just unfrozen, they are very very warm. I know there was as study that disproves any link to warmer lake surface temps. and LES but I can't help to think...

Go TEXAS!!!!!!
let him supply you with it!

[Portastorm]

Here are links to Cosgrove's weekly newsletter:

http://www.examiner.com/article/weatheramerica-newsletter-saturday-january-19-2013-at-7-20-p-m-ct-part-1

http://www.examiner.com/article/weatheramerica-newsletter-saturday-january-19-2013-at-7-20-p-m-ct-part-2

[Ntxw]

I like what the 0z GFS is hinting at after the 28th large scale. Not a great pattern for Arctic outbreak, but you if you like rain and maybe snow, it's the better bet.

[aggiecutter]

Battle of the models.

EURO operational says blowtorch.
http://www.ecmwf.int/products/forecasts ... 3012000!!/

NCEP ENSEMBLES says trough for Central U.S.
http://www.esrl.noaa.gov/psd/map/images ... 64_us.html

[Portastorm]

A very insightful forecast discussion this morning out of HPC, highlighting the uncertainty of model scenarios as well as the volatility of the pattern. I would expect to see more changes in the model runs in the days ahead.

***********************
EXTENDED FORECAST DISCUSSION...CORRECTION ...LINES 23/24
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
1106 AM EST SUN JAN 20 2013

VALID 12Z WED JAN 23 2013 - 12Z SUN JAN 27 2013


FORECAST CHALLENGES ARE MANY ALONG THE SOUTHERN FRINGES OF THE
ARCTIC BOUNDARY FROM THE SOUTH CENTRAL HIGH PLAINS...EASTWARD
ACROSS THE SOUTHEAST AND PIEDMONT. FROM P-TYPE AND MAX TEMPS TO
UNSEASONABLY LOW MIN TEMPS IN THE DEEP SOUTH AND MODEL QPF OUTPUT
ALONG THE NORTHEAST COAST... THE RUN-TO-RUN VARIATION/SPREAD
REMAINS LARGE.

AS IT RELATES TO THE CONSIDERABLE SPREAD...WHAT HAS BEEN AN
INTERESTING ARTIFACT OF THE WINTER RECON OUTPUT IS HOW THE
INFLUENCE OF PERTURBATIONS IN THE SOUTHERN STREAM OFF THE
CALIFORNIA COAST ACT TO SUPPRESS THE SURFACE WAVE TRACK ATOP THE
ARCTIC DRAPE ALONG 40N_LATITUDE AND EAST OF 95W_LONGITUDE.

THE PREMISE HERE IS...AND THE FORECAST PHILOSOPHY FOR THE
SYNOPTIC-SCALE FRONTS...ETC AND THE MEDIUM RANGE TEMPS/POPS...IT
WILL BE EXTREMELY DIFFICULT TO GENERATE AND MAINTAIN A SIGNIFICANT
SYNOPTIC-SCALE CYCLONE IN THE DEEP CORE OF AN ARCTIC AIRMASS. WHAT
THE MANUAL GRAPHICS HAVE ATTEMPTED TO PRESERVE HAVE BEEN THE
'WEAK' CLIPPER SYSTEMS EXITING THE ROCKIES...VS THE FULL-BLOWN
DEEP WINTER CYCLONES WITH BROAD GOMEX MOISTURE INFLOW AND
TRANSPORT NORTHWARD THROUGH THE MS VALLEY. NOT THAT UPGLIDE AND
ISENTROPIC LIFT WILL BE ABSENT...BUT SOLUTIONS THAT PROJECT
INTENSIFICATION WEST OF 90W _ LONGITUDE (AT ANY LATITUDE) AND
FURTHER STRENGTHENING INTO SUB 1000 MB SYSTEMS DOWNSTREAM WITH A
STORM TRACK MIGRATING DIRECTLY INTO THE CORE OF THE ARCTIC AIRMASS
ARE EXTREME. OVER THE PAST 4-5 DAYS...THESE ARE THE SYSTEMS WE
HAVE IGNORED (TRACKS ACROSS THE CENTRAL GREAT LAKES).

THAT SAID...AS HAS BEEN THE CASE...ASPECTS OF THE OPERATIONAL
ECMWF/GFS SOLUTIONS...INCLUDING THEIR MEANS... MAINTAIN GOOD
CONTINUITY WITH THE PREVIOUS PROGS...IE WITH THE FRONTAL
PROGRESSION AS A SERIES OF ARCTIC BOUNDARIES DESCEND UPON THE
EASTERN CONUS. AND LIKEWISE...WITH THE EASTERN PACIFIC FLOW
PATTERN AND THE PROGRESSION OF THE PACIFIC FRONTS (TIMING OF THE
EROSION OF THE UPPER-LEVEL RIDGE). CONFIDENCE IS INCREASING WITH
THE MEDIUM RANGE FLOW PATTERN ALOFT.

WHAT RUN-TO-RUN ISSUES THERE ARE...LIE IN THE WEAK MID-LEVEL
INTERACTIONS/DETAILS...AND MORE IMPORTANTLY... WITH OR
WITHOUT...SOUTHERN STREAM INFLUENCE. THE 20-00Z GFS/GEFS MEAN IS
NOW A QUICKER SOLUTION WITH THE FEATURE FLOUNDERING INVOF 30N 135W
AND ALLOWING THE EJECTION OF SOME H5 ENERGY/IMPULSE EASTWARD.
MANUAL GRAPHICS HONOR THIS TREND BUT DO MAINTAIN SOME ASPECT OF
THE PREVIOUS 2 ECMWF MEAN SOLUTIONS...WHICH HAVE NOT WAVERED FROM
SOME SOUTHERN STREAM INFLUENCE. JUST NOT AT THE PACT OF THE
GEFS/GFS. ...THERE WILL BE ANOTHER WINTER RECON G4 FLIGHT TODAY...

WHAT SERVES AS A HIGHLIGHT OF SORTS IN THIS MEDIUM RANGE PACKAGE
WILL BE THAT THE ARCTIC CHILL IS A GIVEN EAST OF THE MISSISSIPPI.
AND THE SENSIBLE WEATHER VARIATIONS...WILL BE THE STORY ALONG THE
MODIFIED ARCTIC DRAPE AND THE THERMAL GRADIENTS ALONG ITS
EXTREMELY-SLOPED EDGES. PARTICULARLY INVOF THE GULF
STREAM....THERE WILL AND STILL IS TREMENDOUS VOLATILITY JUST ABOVE
THE CONDITIONALLY-UNSTABLE LOW-LAYER DRY/VERY COLD ARCTIC AIRMASS.
BUT LIKEWISE...ALONG THE WESTERN PERIPHERY OF THE ARCTIC
DRAPE...ESPECIALLY ALONG THE ENTIRE FRONT RANGE OF THE
ROCKIES...AND SOUTHERN PLAINS. THESE REGIONS WILL BE FIRST TO
INTERACT WITH THE PACIFIC FLOW EMANATING FROM BOTH STREAMS BY DAY
7.

VOJTESAK

[SaskatchewanScreamer]

You can't get a better offer than this.......transportation however is your problem.


My whole city will throw ours in as a bonus.

[Texas Snowman]

Hmmmmmmm....

"THERE WILL AND STILL IS TREMENDOUS VOLATILITY JUST ABOVE
THE CONDITIONALLY-UNSTABLE LOW-LAYER DRY/VERY COLD ARCTIC AIRMASS. BUT LIKEWISE...ALONG THE WESTERN PERIPHERY OF THE ARCTIC DRAPE...ESPECIALLY ALONG THE ENTIRE FRONT RANGE OF THE
ROCKIES...AND SOUTHERN PLAINS. THESE REGIONS WILL BE FIRST TO
INTERACT WITH THE PACIFIC FLOW EMANATING FROM BOTH STREAMS..."

[BigB0882]

What does that mean? lol

[SaskatchewanScreamer]

pic is courtesy of
Cmdr_Hadfield

Houston, Texas, home of the Johnson Space Center, where I lived and worked for the past 20 years. pic.twitter.com/YLtOBH3k




What I want to know is what is the white showing in the pic???? I know it isn't snow....

[Portastorm]

Hmmmmmmm....

"THERE WILL AND STILL IS TREMENDOUS VOLATILITY JUST ABOVE
THE CONDITIONALLY-UNSTABLE LOW-LAYER DRY/VERY COLD ARCTIC AIRMASS. BUT LIKEWISE...ALONG THE WESTERN PERIPHERY OF THE ARCTIC DRAPE...ESPECIALLY ALONG THE ENTIRE FRONT RANGE OF THE
ROCKIES...AND SOUTHERN PLAINS. THESE REGIONS WILL BE FIRST TO
INTERACT WITH THE PACIFIC FLOW EMANATING FROM BOTH STREAMS..."

What this means, if I understand correctly, is that there will be significant potential for very strong low pressure systems to develop in the zone of baroclinic instability (i.e. where the warmer and colder airmasses meet). And that would be in a "U shape" from along the front range of the Rockies down into the Southern Plains and back up northeast. As we have seen references to here and on other forums, we may be looking at a storm like what we saw around Christmas time. Snow and ice to the north and heavy thunderstorms to the south.

Also ... anyone see the end of the 12z Euro run? Looks pretty cold and stormy to me for us in Texas.

[Texas Snowman]

Don't forget what Ntxw said several days ago, there are two ways for Wxman57 to be denied spring warmth. One is the direct discharge of arctic cold into Texas and the other is via an active southern branch marching storms into the southern plains.

[vbhoutex]

pic is courtesy of
Cmdr_Hadfield

Houston, Texas, home of the Johnson Space Center, where I lived and worked for the past 20 years. pic.twitter.com/YLtOBH3k
http://img585.imageshack.us/img585/3430/whatisthewhite.png



What I want to know is what is the white showing in the pic???? I know it isn't snow....

It is the sun reflecting off of Galveston Bay. There are some clouds in the NE side of the picture to the East of the bay.

[Ntxw]

I don't trust the Euro 192+ hours out, it has not shown consistency. GFS doesn't have the best solutions but at least overall it's been decent for that same time frame. Week of 28th to Feb 2nd still looks like the best target.

If we get some phasing between the jets on that system it has a lot of room to work with. CFSv2 is advertising below average first half of February.