Texas winter wx thread (2009-2010)

[Portastorm]

Interesting to note this morning that the 0z Euro lags the upper low behind the surface cyclone in the Gulf by an increased amount of time compared to Sunday's runs. Whether that means more rain and/or ice or snow for someome in Texas remains to be seen. But it would mean even more precip.

The 0z GFS has a QPF bomb of almost five inches (of rain that is) over Austin!

[srainhoutx]

Interesting to note this morning that the 0z Euro lags the upper low behind the surface cyclone in the Gulf by an increased amount of time compared to Sunday's runs. Whether that means more rain and/or ice or snow for someome in Texas remains to be seen. But it would mean even more precip.

The 0z GFS has a QPF bomb of almost five inches (of rain that is) over Austin!

Almost the same here in Houston Portastorm. San Angelo looks to have the best shot of any wintry precip, if at all from this event via overnight runs. Concerned that Coastal areas will have flooding issues from long fetch E to ESE winds from this event. Looks like a stormy and heavy rainfall event at this point folks.



AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
515 AM CST MON JAN 11 2010

.DISCUSSION...
SURFACE RIDGE AXIS IS DRAPED ACROSS THE CWA FROM WEST TO EAST AND
WILL SET THE STAGE FOR A WARMER AFTERNOON AFTER THIS MORNINGS
PLUNGE INTO THE FREEZER. CLEAR SKIES WILL BE CHANGING AS CIRRUS TO
THE WEST SPREADS ACROSS THE AREA THIS MORNING AND AFTERNOON.
TEMPERATURES SHOULD RISE INTO THE 50S AT ALL SITES TODAY AND WOULD
RULE OUT A 60 DEGREE REPORT AT EDNA. TEMPERATURES FALL OFF AGAIN
TONIGHT BUT ONLY THE NORTHEAST 1/2 OF THE CWA SHOULD DROP TO
FREEZING OR BELOW.

TUE 00Z A COLD FRONT NEAR THE RED RIVER WILL DROP SOUTH AND SHOULD
REACH THE HOUSTON METRO AREA AROUND 15Z TUESDAY. THIS WILL
REINFORCE THE COOL AND DRY AIR BUT OUR WEATHER PATTERN WILL BE
UNDERGOING SOME MAJOR CHANGES THIS WEEK. AFTER THIS RECORD SETTING
ARCTIC COLD SNAP THE PATTERN WILL BECOME DOMINATED BY A SLOW
MOVING UPPER LOW TRACKING THROUGH THE SW U.S. AND NRN MEX WED-FRI.
THE 850 RIDGE OVER CRP 12Z WED WILL SHIFT EAST LEADING TO
INCREASINGLY STRONG SE-E FLOW. VIGOROUS MOISTURE RETURN THURSDAY
WILL MOISTEN UP THE ATMOSPHERE DRAMATICALLY AND THE RAINS SHOULD
BEGIN. SOME INDICATIONS ARE THAT THE COASTAL WATERS MAY BE VERY
ACTIVE THURSDAY THEN EXPAND NORTH. THE STRONG FLOW WILL LIKELY
LEAD TO ELEVATED TIDES...SEE MARINE SECTION FOR MORE DETAILS.
SOUNDINGS APPEAR TO BE VERY SATURATED AND CAPABLE OF PERIODS OF
HEAVY RAINFALL THURSDAY EVENING THROUGH FRIDAY AFTERNOON. WILL
CARRY FAIRLY HIGH POPS FOR THIS PERIOD WITH SHRA/TSRA
TRANSITIONING TO RA/SHRA SATURDAY AS THE UPPER LOW PULLS AWAY.
GFS/ECMWF ARE BOTH SIMILAR WITH SURFACE CYCLOGENESIS IN THE
COASTAL BEND REGION TO NEAR MATAGORDA BAY...EVENTUALLY KICKING OUT
A LOW ESE ARCING UP FRIDAY NIGHT INTO LA. SLOWER UPPER MOVEMENT
RESULTS IN A SURFACE LOW STILL OVER HARRIS COUNTY AT 12Z SATURDAY
PER ECMWF WHEREAS THE GFS HAS A MORE ORGANIZED SURFACE LOW SOUTH
OF LA. WILL BE FOLLOWING THE ECMWF SOLUTION WITH THE SLOWER
MOVEMENT GIVEN THE UPPER CUTOFF FLOW. AS FOR TEMPERATURES HAVE
TRENDED POPS TOWARD THE MEX GUIDANCE BUT HAVE BIASED THESE WARMER
ON MINS AND COOLER ON MAX TEMPS ON ACCOUNT OF THE THICK CLOUD
COVER AND RAINFALL.

[srainhoutx]

Just an FYI: After the weekend warmup, the 14 day ensemble means go back to a -AO and -NAO pattern. Winter is far from over IMHO.

[srainhoutx]

HPC Prelim Extended Disco...remember Ida...

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
834 AM EST MON JAN 11 2010

VALID 12Z FRI JAN 15 2010 - 12Z MON JAN 18 2010

...ANOMALOUSLY STRONG SOUTHERN STREAM SYSTEM NEAR THE GULF COAST
LATE THIS WEEK...

SYSTEMS MOVING THROUGH THE MAIN BELT OF THE WESTERLIES WILL BE
PROGRESSIVE AS THE POLAR VORTEX MOVES FROM FAR NORTHERN CANADA
TOWARDS THE NORTH POLE...ACTING TO SPEED UP THE WESTERLY FLOW IN
THE MID-LATITUDES OF THE NORTHERN HEMISPHERE. THE SPLIT-FLOW
REGIME SEEN SINCE AT LEAST NOVEMBER WILL CONTINUE...THOUGH WITH AN
INCREASINGLY ZONAL PACIFIC JET CUTTING THROUGH THE EASTERN PACIFIC
AND AIMING TOWARDS CALIFORNIA...SYSTEMS MOVING THROUGH THE
SOUTHERN STREAM SHOULD BE MORE POTENT. IN KEEPING WITH THE SPIRIT
OF WHAT IS EVOLVING INTO A MORE TYPICAL FLOW PATTERN DURING EL
NINO CLIMATE REGIMES...WILL FAVOR THE GUIDANCE THAT MAINTAINS
SEPARATION BETWEEN THE NORTHERN AND SOUTHERN STREAMS WITH A
PREFERENCE TOWARDS STRONGER SOUTHERN STREAM SYSTEMS...WHICH FAVORS
THE 00Z CANADIAN/00Z ECMWF/00Z ECMWF ENSEMBLE MEAN/00Z GEFS MEAN.
THE PRESSURES USED A SIMPLE BLEND OF THE 00Z CANADIAN AND 00Z
ECMWF THROUGH THE PERIOD...WHICH MAINTAINED REASONABLE CONTINUITY.
THE PROGRESSIVE NATURE OF THE WESTERLIES ENSURES LOW CONFIDENCE
IN THE PREDICTABILITY OF SMALLER DETAILS AND COULD LEAD TO SWINGS
IN THE DETERMINISTIC/MANUAL GUIDANCE FROM RUN-TO-RUN AND
DAY-TO-DAY MID TO LATE PERIOD...SIMILAR TO WHAT WE SAW DURING THE
LESS PREDICTABLE LATE OCTOBER/EARLY NOVEMBER 2009 TIME FRAME.

...WEST...
A SYSTEM CLIPPING THE PACIFIC NORTHWEST SHOULD BRING HEAVY
PRECIPITATION PRIMARILY TO BRITISH COLUMBIA/VANCOUVER ISLAND...BUT
ONLY A SMALL SHIFT TO THE SOUTHEAST WITH THIS SYSTEMS TRACK WOULD
BRING THE THREAT INTO WESTERN WASHINGTON STATE. THE POSITION OF A
POSITIVE ANOMALY CENTER WHICH IS POSITIVELY TILTED OVER ONTARIO
FAVORS A NEGATIVE TILTED TROUGH POINTED INTO CALIFORNIA...WHICH
SHOULD LEAD TO WETNESS ACROSS SECTIONS OF THE GOLDEN STATE THIS
WEEKEND INTO EARLY NEXT WEEK. DUE TO THE STRENGTH OF HIGH
PRESSURE IN ADVANCE OF THIS SYSTEM /AND THE WAKE OF THE GULF COAST
SYSTEM/ ITS SURFACE REFLECTION SHOULD BE LOST BY SUNDAY MORNING.

...GULF COAST/EAST...
A LARGE AND ANOMALOUSLY DEEP CYCLONE MOVING THROUGH SOUTH TEXAS
AND THE GULF OF MEXICO DAYS 3-5 SHOWS GOOD AGREEMENT ON TRACK AND
INTENSITY...INCLUDING THE LIKELIHOOD OF HEAVY RAIN ACROSS PORTIONS
OF EASTERN TEXAS THE CENTRAL GULF COAST STATES. STANDARDIZED
ANOMALIES ACROSS MEXICO IN BOTH THE 500 HPA HEIGHT PATTERN AND 850
HPA TEMPERATURE PATTERN ARE IMPRESSIVE...APPROACHING 6 AND 4
SIGMAS BELOW NORMAL RESPECTIVELY. THIS ATYPICALLY COLD AIR ALOFT
WILL INTERACT WITH THE NATURAL TEMPERATURE GRADING IN THE
NORTHWEST GULF OF MEXICO...AND SHOULD LEAD EXPLOSIVE CONVECTIVE
DEVELOPMENT WITHIN THE GULF OF MEXICO IN 4-5 DAYS TIME WHICH
SHOULD DEEPEN THE SURFACE LOW. IN SOME RESPECTS...THIS IS SIMILAR
TO THE FLOW PATTERN AROUND NOVEMBER 8-9 2009...BUT WITH STRONGER
DYNAMICS ALOFT AND NO TROPICAL CYCLONE INVOLVED. THE GFS IS A
FAST OUTLIER WITH THIS SYSTEM. SINCE ITS QUICK SOLUTION IS NOT
SUPPORTED BY THE 00Z MULTI-MODEL ENSEMBLE MEMBERS...DISCOUNTED ITS
SOLUTION. IF THE GUIDANCE IS SOMEHOW A LITTLE TOO WEAK WITH THIS
SYSTEM...MEASURABLE FROZEN PRECIPITATION WOULD BE POSSIBLE ACROSS
SOUTHERN/CENTRAL TEXAS AS 850 HPA TEMPERATURES ARE BARELY ABOVE
FREEZING WITHIN ITS EXPECTED COMMA HEAD. ONCE THE SYSTEM LIFTS
OUT ALONG THE GULF COAST/DEEPENS NEAR AND OFFSHORE THE EAST
COAST...PRECIPITATION COULD START AND END AS FROZEN ACROSS THE
MID-ATLANTIC/NEW ENGLAND STATES THIS WEEKEND INTO EARLY NEXT WEEK.
STAY TUNED.
ROTH/JAMES

[Texas Snowman]

How cold has this slowly eroding arctic air mass been in the Red River Valley of North Texas? A 33-acre lake in Denison (Waterloo Lake) is totally frozen over at least an inch thick in most places!!!

I am also told that there is significant icing on portions of Lake Texoma, particularly on the 89,000 acre reservoir's upper ends.

To put this in perspective, here is a little winter weather FYI for this part of the world: Texoma partially froze over in 1983 (Big Mineral Arm was totally frozen, only the main lake channel remained open). Ice was so thick in 1983 that local duck hunters were sliding across it for miles in their airboats to a few open spots of water along the Red River channel.

This freeze wasn't nearly that bad, of course, but it has been years since I've seen this 33-acre lake totally frozen.

Pretty amazing...

[wxman22]

I found this interesting (from HPC discussion)

IF THE GUIDANCE IS SOMEHOW A LITTLE TOO WEAK WITH THIS
SYSTEM...MEASURABLE FROZEN PRECIPITATION WOULD BE POSSIBLE ACROSS
SOUTHERN/CENTRAL TEXAS AS 850 HPA TEMPERATURES ARE BARELY ABOVE
FREEZING WITHIN ITS EXPECTED COMMA HEAD. ONCE THE SYSTEM LIFTS
OUT ALONG THE GULF COAST/DEEPENS NEAR AND OFFSHORE THE EAST
COAST...PRECIPITATION COULD START AND END AS FROZEN ACROSS THE
MID-ATLANTIC/NEW ENGLAND STATES THIS WEEKEND INTO EARLY NEXT WEEK.
STAY TUNED.ROTH/JAMES

[txagwxman]

Not enough cold air behind this system for snow Austin, but still 5 days out. Thicknesses are 546-548, 545 on the GEM.

[srainhoutx]

I found this interesting (from HPC discussion)

IF THE GUIDANCE IS SOMEHOW A LITTLE TOO WEAK WITH THIS
SYSTEM...MEASURABLE FROZEN PRECIPITATION WOULD BE POSSIBLE ACROSS
SOUTHERN/CENTRAL TEXAS AS 850 HPA TEMPERATURES ARE BARELY ABOVE
FREEZING WITHIN ITS EXPECTED COMMA HEAD. ONCE THE SYSTEM LIFTS
OUT ALONG THE GULF COAST/DEEPENS NEAR AND OFFSHORE THE EAST
COAST...PRECIPITATION COULD START AND END AS FROZEN ACROSS THE
MID-ATLANTIC/NEW ENGLAND STATES THIS WEEKEND INTO EARLY NEXT WEEK.
STAY TUNED.ROTH/JAMES

I agree Don. It's going to be a close call. We may not know until Tuesday into Wednesday once we get some good RAOBS sampling from this system. Bears Watching on many different levels.

[wxman22]

Here's my early take on the system, looks like a very powerful Gulf low will develop Thursday into Friday off the Middle Texas coast. Pumping in copious gulf moisture with heavy banding developing and moving ashore through east Texas and Central Texas then expanding into north and West central Texas.

There is potential for very heavy rainfall amounts with this system in Central and Southeast Texas.That could lead to flooding problems.There also could be some pretty bad coastal flooding along the coast as the system parallels the coast there could be enough instability to produce a MCS that could lead to some severe weather but that's a little questionable right now. As the low pushes to the east of us toward Louisiana strong winds will be possible maybe gusting as much as 50mph along the coast.,this system of course is not tropical in nature (being cold core), but Conditions may be very similar to getting a moderate tropical Storm.

On the backside of the low if the system is able to tap into enough cold air there could be p-type issues with sleet and maybe even snow mixing in the wraparound moisture. But for right now it looks a little to warm aloft,and I feel that we wont really know until we get some sampling into the models of the strength of the storm around Wednesday as the system comes ashore the West coast.

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 the NHC and NWS products.

[Portastorm]

I like your thinking so far wxman22. Good discussion!

[txagwxman]

Here's my early take on the system, looks like a very powerful Gulf low will develop Thursday into Friday off the Middle Texas coast. Pumping in copious gulf moisture with heavy banding developing and moving ashore through east Texas and Central Texas then expanding into north and West central Texas.

There is potential for very heavy rainfall amounts with this system in Central and Southeast Texas.That could lead to flooding problems.There also could be some pretty bad coastal flooding along the coast as the system parallels the coast there could be enough instability to produce a MCS that could lead to some severe weather but that's a little questionable right now. As the low pushes to the east of us toward Louisiana strong winds will be possible maybe gusting as much as 50mph along the coast.,this system of course is not tropical in nature (being cold core), but Conditions may be very similar to getting a moderate tropical Storm.

On the backside of the low if the system is able to tap into enough cold air there could be p-type issues with sleet and maybe even snow mixing in the wraparound moisture. But for right now it looks a little to warm aloft,and I feel that we wont really know until we get some sampling into the models of the strength of the storm around Wednesday as the system comes ashore the West coast.

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 the NHC and NWS products.

If there is snow---it will be very wet...maybe ACT to DFW...but ain't buying it yet, we need more cold air to play with.

[srainhoutx]

Well the 12Z GFS flipped back to a colder solution. Too soon to know what will fall post frontal and behind the Potent Upper Low. My guess is a cold rain/sleet mix and perhaps some very wet snow via this run. Also looks very windy as well.

[Portastorm]

Several quick things pique my attention from the 12z GFS run:

1) Obvious potential for significant accumulation of wintry wx in south central Texas

2) Colder look to the pattern despite the 12z GFS runs being normal than the 0z runs pretty much all winter

3) Stronger high nudging into the Rockies at about 114 hours. 12z run shows a 1032mb high while the 0z had it at 1028mb.

[iorange55]

I have no idea with this storm, so I'm just listening to everyone, and watching the models.

[AggieSpirit]

Thought you guys might like this -- this is a picture of the the British Island COMPLETELY covered by ice and snow.

http://news.bbc.co.uk/2/hi/in_depth/8447023.stm

[wxman22]

Well 12z GFS is a step in the right direction hopefully the trend continues...

[iorange55]

Thought you guys might like this -- this is a picture of the the British Island COMPLETELY covered by ice and snow.

http://news.bbc.co.uk/2/hi/in_depth/8447023.stm

Good lord.

[wxgirl69]

Just an FYI: After the weekend warmup, the 14 day ensemble means go back to a -AO and -NAO pattern. Winter is far from over IMHO.

Does that mean there is more cold up North.. We just need to wait for a chunk of it to break off and shoot down South.
Are there any hints of it coming down later down the road?

[cycloneye]

For Portastorm,Steve and others who always want to see the latest on how is ENSO doing,here is todays update by Climate Prediction Center.There were decreases in the anomaly temperatures at El Nino 1-2 and El Nino 3 areas,but overall,no big changes from the previous status of El Nino that continues to be in a moderate to strong status.

Last Week Numbers

Niño 4= +1.4ºC
Niño 3.4= +1.8ºC
Niño 3= +1.4ºC
Niño1+2= +0.7ºC

This Week Numbers

Niño 4= +1.5ºC
Niño 3.4= +1.8ºC
Niño 3= +1.2ºC
Niño1+2= +0.3ºC

http://www.cpc.ncep.noaa.gov/products/a ... ts-web.pdf

[txagwxman]

ECMWF all rain...552 thickness not cold enough.