Texas Winter 2011-2012...

[Portastorm]

About the only correction I would to that map is moving that 6" swath over the Texarkana area. Other than that, the map looks pretty good.

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org. For official information, please refer to NWS products.

You did notice the Omega block over Austin, right? I'll be building another coldrainman this weekend. Oh well, the rain is great.

Speaking of which ... picked up about 3/4" at the PWC today but now we're getting dry slotted from dry air outta NE Mexico. That could be it for my part of the state in terms of rainfall with this event.

[orangeblood]

Canadian hangs energy back in Cal and cold/dry. At least the trend for vorticity isnt out to sea.

It appears the model isn't sure what to do with that energy and so it keeps it stationary then gets scoured out a little piece at a time....not sure how plausible that scenario is??

[TeamPlayersBlue]

6.08 inches of rain here in Sugar Land today. Rain has eased up right now, but were getting rain at almost 4 inches per hour. The echo on a storm south of Houston has a the classic 'hook' feature on it. There is already a tornado warning out for the area

[ndale]

About the only correction I would to that map is moving that 6" swath over the Texarkana area. Other than that, the map looks pretty good.

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org. For official information, please refer to NWS products.

You did notice the Omega block over Austin, right? I'll be building another coldrainman this weekend. Oh well, the rain is great.

Speaking of which ... picked up about 3/4" at the PWC today but now we're getting dry slotted from dry air outta NE Mexico. That could be it for my part of the state in terms of rainfall with this event.

Portastorm if the 12gfs map on wunderground map was to verify for precipitation type it shows snow all the way down to San Antonio on Monday the 16th. I know it's probably dreamland but just a thought.

[Portastorm]

Dreams gotta start somewhere, right?!

No, I had not seen that particular map yet. I was briefly scanning the 12z GFS per Alan Hoffman's site. I didn't realize the GFS progged snowfall that far south. What I saw was snow in west/northwest/north Texas. Will look again.

[Ntxw]

Euro looks cold and dry, with maybe a frontal passage light snow. It still hangs the storm west of Cal. Ukmet about the same.

Edit: There appears to be some serious vast amounts cold air by both the GFS and Euro runs in Canada.

[orangeblood]

Euro looks cold and dry, with maybe a frontal passage light snow. It still hangs the storm west of Cal. Ukmet about the same.

Edit: There appears to be some serious vast amounts cold air by both the GFS and Euro runs in Canada.

Another showdown between the Domestic vs. International models, which are vastly different in their handling of the energy on the west coast!! I'll give the American models a Tebow like chance...Can they pull of another miracle???

[Ntxw]

^ Canadian has it on and off, same for the GFS. I hope the Euro eventually shows it at least once! There's usually a big storm accompanied by strong polar/arctic fronts, I just would like it better if the southern energy is involved!

Also Henry's Margusity has been chiming about the demise of La Nina. If we can get the MJO to finally overpower it(Also lead to the 7-8-1 phases) region briefly for Feb, that signal and with SOI values of late it could be hints that next winter might go El Nino!

[aggiecutter]

Interesting, that the 12z GFS brings two waves winter precipitation across North and NE Texas late next weekend and early next week.

http://coolwx.com/cgi-bin/getptype.cgi? ... ield=ptype

[Portastorm]

Interesting, that the 12z GFS brings two waves winter precipitation across North and NE Texas late next weekend and early next week.

http://coolwx.com/cgi-bin/getptype.cgi? ... ield=ptype

I *could* be looking at the model maps incorrectly, but I see sunny with highs in the 60s for Texarakana all weekend.

[Ntxw]

Interesting, that the 12z GFS brings two waves winter precipitation across North and NE Texas late next weekend and early next week.

http://coolwx.com/cgi-bin/getptype.cgi? ... ield=ptype

GFS showed a classic overrunning event. These type of scenarios can bring hefty snow totals to those just above the freezing line. All of the big snow events for north, northeast Texas featured such a scenario.It probably won't happen that way, but that is why it's showing several rounds of precip.

[wxman57]

:uarrow:

Dreams gotta start somewhere, right?!

No, I had not seen that particular map yet. I was briefly scanning the 12z GFS per Alan Hoffman's site. I didn't realize the GFS progged snowfall that far south. What I saw was snow in west/northwest/north Texas. Will look again.

Actually, the 12Z GFS has the precip ending in San Antonio just after 18Z Sunday (early afternoon). Here's a GFS-generated upper-air sounding valid 18Z Sunday as the precip comes to an end. Note that the entire precip column is above freezing, meaning no frozen precip.

[PTrackerLA]

If the GFS were to hold true are we talking about freezing rain or snow for those north of the blue line? I associated overrunning storms with ice storms but don't know where to find that sort of data this far out.

[Ntxw]

If the GFS were to hold true are we talking about freezing rain or snow for those north of the blue line? I associated overrunning storms with ice storms but don't know where to find that sort of data this far out.

You can do what wxman just did and use forecast soundings. Ice storms are usually associated with shallow cold air masses (850 temps warm but surface temps below 32), the one shown on the GFS doesn't seem shallow.

[Portastorm]

HPC chimes in this afternoon with some interesting comments about the model runs:

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
224 PM EST MON JAN 09 2012

VALID 12Z THU JAN 12 2012 - 12Z MON JAN 16 2012

THE LARGE-SCALE MODEL SOLUTIONS ARE IN RELATIVELY GOOD AGREEMENT
WITH THE EVENTUAL TRANSITION FROM A SPLIT-FLOW AND SOUTHERN STREAM
INFLUENCED WEATHER PATTERN...DAYS 3-5...TO MORE OF A ZONAL FLOW
ACROSS THE NORTHERN TIER/CANADIAN BORDER FROM COAST TO
COAST...DAYS 6-7.

TO FINISH UP OR TRANSITION AWAY FROM THIS SPLIT-FLOW PATTERN...THE
CUTOFF LOW/SHORTWAVE INVOF BAJA AND THE DESERT SOUTHWEST WILL NEED
TO PROGRESS EASTWARD. AS WAS THE PREFERENCE IN THE PREVIOUS
PROGS...THE NAEFS/ECMWF MEANS HAVE THE GENERIC MATTERS IN
HAND...BUT THE FINER DAY TO DAY DETAILS ARE A BIT MUDDLED.

THE DETERMINISTIC GFS/ECMWF/CANADIAN AND UKMET HAVE A WIDE VARIETY
OF POSSIBLE SOLUTIONS. THE 9/00Z OPERATIONAL ECMWF/CANADIAN ARE
THE SLOWER...CLOSED SOLUTIONS ALOFT VS THE UKMET/GFS ACROSS THE
DESERT SOUTHWEST AND SONORA. FROM PREVIOUS EXPERIENCE IN THE
SHORTER TERM...JAN 6...THE ASSUMPTION WAS TO GO WITH THE SLOWER
SOLUTIONS. THIS HAS PREVAILED/VERIFIED...AND THE 'NEW'
CUTOFF...OUR DAY 3-5 CONCERN ALONG THE NW CALIF COAST...HAS
WAFFLED BETWEEN A 6/12Z GFS-LIKE OFFSHORE SOLUTION TO THE OTHER
EXTREME...AN INLAND WAVE...6/12Z UKMET/CANADIAN. GIVEN THE
CONTINUED SPREAD...THE NAEFS SEEMED REASONABLE TO COVER THE SPREAD
DOWNSTREAM ACROSS THE SOUTHERN PLAINS AND MIDWEST...BEYOND DAY 5.


12Z CYCLE UPDATE...SUBTLE DIFFERENCES ALOFT...PARTICULARLY OVER
THE SOUTHERN PLAINS AND THE DESERT SOUTHWEST...REMAIN UNRESOLVED
BEYOND DAY 5 GIVEN THE DIFFERENCES BETWEEN THE MUCH FASTER GFS AND
THE SLOWER...ECMWF. THE FORECAST PHILOSOPHY DOESNT CHANGE
MUCH...AND PROGS WERE NOT UPDATED FOR THE FINAL. THE THOUGHT IS TO
MAINTAIN THE BULK OF THE ENERGY INTO DAY 4-5 IN THE NRN GULF OF
CALIFORNIA WITH THE SOUTHERN STREAM EJECTING SHORTWAVES ENEWD
ACROSS TEXAS...THE SOUTHERN PLAINS AND THE SOUTHEAST. UNLIKE THE
PRESENT SYSTEM...MODELS NEVER DEVELOP MUCH IN THE WAY OF A
SOUTHERN STREAM SURFACE WAVE...GIVEN COLD HIGH PRESSURE WILL BE
LOCKED IN PLACE...QUITE STABLE AND AN OPEN GULF OF MEXICO AND ITS
LOW-LEVEL MOISTURE WILL BE CONFINED TO THE RIO GRANDE VALLEY FOR
MUCH OF THE MEDIUM RANGE/EXTENDED.

[wxman57]

If the GFS were to hold true are we talking about freezing rain or snow for those north of the blue line? I associated overrunning storms with ice storms but don't know where to find that sort of data this far out.

What blue line? And remember, when you look at those model graphics showing precip that the precip isn't necessarily occurring at the valid time of the map. The map displays precipitation that is forecast to fall in the 3, 6 or 12 hours PRIOR to the valid time of the map. If you're looking beyond 192 hrs, then the map may be displaying precip that fell 8-12 hours prior to the valid time of the map when upper air temps were a good bit warmer.

[PTrackerLA]

If the GFS were to hold true are we talking about freezing rain or snow for those north of the blue line? I associated overrunning storms with ice storms but don't know where to find that sort of data this far out.

What blue line? And remember, when you look at those model graphics showing precip that the precip isn't necessarily occurring at the valid time of the map. The map displays precipitation that is forecast to fall in the 3, 6 or 12 hours PRIOR to the valid time of the map. If you're looking beyond 192 hrs, then the map may be displaying precip that fell 8-12 hours prior to the valid time of the map when upper air temps were a good bit warmer.

The 0 degrees Celsius line on the GFS 10m_wnd_precip maps. I know we will be far too warm this far south to see anything frozen (if this system is even real.)

[wxman57]

If the GFS were to hold true are we talking about freezing rain or snow for those north of the blue line? I associated overrunning storms with ice storms but don't know where to find that sort of data this far out.

What blue line? And remember, when you look at those model graphics showing precip that the precip isn't necessarily occurring at the valid time of the map. The map displays precipitation that is forecast to fall in the 3, 6 or 12 hours PRIOR to the valid time of the map. If you're looking beyond 192 hrs, then the map may be displaying precip that fell 8-12 hours prior to the valid time of the map when upper air temps were a good bit warmer.

The 0 degrees Celsius line on the GFS 10m_wnd_precip maps. I know we will be far too warm this far south to see anything frozen (if this system is even real.)

Yes, that blue line represents where the GFS thinks the temperature at the surface may be freezing. But it doesn't say anything about how far up the freezing temperatures go. Could be just a shallow layer of sub-freezing air at the surface and 50 deg temps aloft. And, as I said, seeing green (precip) on the maps south of the 0 deg (freeze) line doesn't mean there is precip occurring south of the freezing line, as the precip could have fallen long before the temperature reached freezing at the surface.

[Big O]

Some mets and well thought of amateurs on another message board are suggesting that the only winner (at least for the foreseeable future) of the -WPO, -AO will be Canada. While there is cross-polar flow, they argue that there is no mechanism to dislodge that air into the southern Plains, or much of the US for that matter. In fact, they point to the 240h European, which they claim depicts a Pacific firehouse jet (i.e., zonal flow) across the US.

I was informed that we need both west and east blocking to force the arctic air southward. However, another well-respected met told me you can't have both east and west blocking. I'm at a loss and am really frustrated with the lack of wintry weather. Someone talk me off the ledge.

[Texas Snowman]

Bastardi tweeted his classic line earlier today: "-AO, look out below."