Texas winter wx thread (2009-2010)

[srainhoutx]

That's quite a list, do you have any sago palms, canary island palms or hybyscus(sp?) ?

I have 5 sagos and they were unharmed - they are hardy down to the teens. I don't have any Canary Island dates but the ones in the area look unharmed as well, I believe they are hardy down to about 15-20.

I forgot to mention the hibiscus - and I have a lot. All my hibiscus got fried pretty badly. Total leaf loss and the top few inches of the branches are mush. They should come back though...that is unless we have another really hard freeze....

We have burns up here too Jason. Our Pigmy Date Palm suffered a bit. My Hass Avocado from seed mind you is showing the stress of 15 hours below freezing and a low of 23.

[vbhoutex]

Jason, I don't know the names of most of the plants I see around, but there was a lot of damage even in the "urban core" because most places in the metro area were below 30f for several hours. Our hibiscus are like yours but will be fine since we did cover them. Bananas, most tropicals are mush from what I have seen. I know at our house near I-10 and Sam Houston Tollway we were at or below freezing for 15-18 hours with quite a bit of that below 30f and a low of 26.7f here at the house. We haven't seen a temp that low in many years here.

[gboudx]

Steve McCauley on WFAA tonight hinted at some possible major changes beginning this weekend. He said he may know a little more tonight at 10 after the latest model runs. It seems at least a few of the meteorologists in the area are picking up on some possible cold weather moving down towards next week.

If anybody will start talking about it, it's McCauley. He's not afraid to step out on a limb, and I like how he produces educational graphics for his forecasts and provides some explanation.

[gofrogs]

GFS run sucks for north texas around christmas aghghghahghgh

[iorange55]

GFS run sucks for north texas around christmas aghghghahghgh

It shows the cold front coming in a like a day after Christmas, but all in all I think the GFS was colder for this weekend, and next week, so I'm pretty happy with it. Would like to see more moisture, though.

[snow and ice]

GFS run sucks for north texas around christmas aghghghahghgh

Nothing could be further from the truth. This is the best looking run of the GFS for winter weather in Texas that I have seen in a long time. Look at the upper air features. Not one, but two vortexs over the northern plains within a 8 days. A sharp trough digging into the central and southern plains. An active subtropical jet with overriding SW winds a loft. If you want winter weather in Texas, that is how you would draw the maps.

Remember, the GFS is notorious for underplaying the southward progression of Arctic air. This debunks the warm trend of the past two days of the GFS. Also, it is now in fairly good agreement with the EURO. This is typical of the GFS. Show something in the long range. Then loose it, and pick it up again.

0z GFS:
http://www.nco.ncep.noaa.gov/pmb/nwprod ... /fpc.shtml

[Texas2Florida]

Steve McCauley on WFAA tonight hinted at some possible major changes beginning this weekend. He said he may know a little more tonight at 10 after the latest model runs. It seems at least a few of the meteorologists in the area are picking up on some possible cold weather moving down towards next week.

If anybody will start talking about it, it's McCauley. He's not afraid to step out on a limb, and I like how he produces educational graphics for his forecasts and provides some explanation.

Good that someone is mentioning it at least, Channel 4 mets said that it will be cool and dry and that there was just too much dry air to let any moisture come up to North Texas for at least the next week or so....I was watching just shaking my head after reading here for the past week and a half.

[Portastorm]

Gofrogs, do not dispair. Snow and ice is right. Don't pay too much attention to the surface temp depiction per the GFS. One of the things that the venerable Wxman57 has taught some of us rank amateurs over the years is to pay attention to the 500mb pattern with the GFS. If you look at that per the 0z run, you can see upper air support to bring down a lot of Polar/Arctic air and you see an active subtropical jet stream. All the ingredients for winter weather in Texas!

In looking at the models, remember that the higher number of millibars, the lower in the atmosphere. So, if you're looking at maps from 200 to 500mb, you're essentially dealing with the upper air features. Close to the surface would be 850mb or even 1000mb. FYI.

[gofrogs]

Wow youll are so right thanks

[srainhoutx]

Some subtle changes overnight via the 00Z guidance noted by the HPC regarding the shorter term (1-3 day) and still a lot of uncertainty in the Medium Range...there will be another Update a little later in the morning...the 00Z ECMWF suggested maybe not as cold as yesterday, but great caution should be used as ALL guidance continues to struggle with the current setup...

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
320 AM EST TUE DEC 15 2009

VALID 12Z SAT DEC 19 2009 - 12Z TUE DEC 22 2009

MODELS SHOW RELATIVELY GOOD AGREEMENT WITH PRIOR RUNS IN ALLOWING
A LARGE REX-BLOCK DEVELOPING FROM GREENLAND TO NEW ENGLAND EARLY
IN THE MEDIUM RANGE PERIOD TO DRIFT SOUTHWARD AND RETROGRADE
CAUSING THE FLOW OVER WESTERN CANADA TO EVENTUALLY SPLIT WITH
SOUTHERN PORTIONS OF THE FLOW AMPLIFYING OVER THE EASTERN CONUS
MIDWAY THROUGH THE PERIOD. MEANWHILE...ACROSS THE NORTHWEST MODELS
SHOW AVERAGE AGREEMENT WITH A SIGNIFICANT SHORTWAVE TROUGH
CLIPPING THE REGION DAY 3 WITH A COLD FRONT PASSING THROUGH THE
AREA BEFORE STALLING AND RETREATING AHEAD OF AN UPPER LOW THAT
COULD REACH THE PACIFIC NORTHWEST COAST BY DAY 5 BEFORE DRIFTING
INLAND. LOTS OF DETAIL DIFFERENCE TO CONSIDER THIS CYCLE...BUT ALL
IN ALL...PREFER THE GFS INCLUDING IN THE WEST WITH THE APPROACHING
UPPER LOW. ALTHOUGH ITS SPEED COULD BE TOO FAST AND MAY MAKE
SLIGHT MANUAL ADJUSTMENTS TO SLOW IT DOWN SOME.
OTHERWISE...AMPLIFYING FLOW OVER THE EASTERN HALF OF THE CONUS
PRESENTS THE LIKELIHOOD THAT SOME DEGREE OF CYCLOGENESIS IS LIKELY
NEAR THE SOUTHEAST COAST DAYS 4/5 AS IT EVENTUALLY INTERACTS WITH
A RESIDUAL BAROCLINIC ZONE IN THE NORTHERN GULF. THE
ECMWF/CANADIAN ALONG WITH EARLIER RUNS OF THE JMA/NOGAPS ARE
EXTREMELY AGGRESSIVE IN REFORMING A SURFACE LOW NEAR THE OUTER
BANKS OF NORTH CAROLINA BY DAY 5 IN WHAT APPEARS TO BE VICINITY OF
THE GULF STREAM... WHILE THE GFS/UKMET/MULTI-MODEL ENSEMBLE MEANS
SHOW MUCH WEAKER SECONDARY LOW DEVELOPMENT AND PROGRESSIVE FLOW
EXTENDING ALONG THE SOUTHEAST COAST. DIFFICULT TO BE SURE THIS FAR
IN ADVANCE...BUT THE MORE PROGRESSIVE AND GENERALLY WEAKER
SOLUTIONS SIMILAR TO THE GFS APPEAR MORE LIKELY WITH AN UPPER LOW
DRIFTING SOUTHWARD FROM HUDSON BAY AND RAPID NORTHWEST FLOW
ORIGINATING ALONG ITS SOUTHWEST PERIPHERY.
JAMES

With that said, Here are some exmaples of what TX WFO's are thinking regarding the next push of Arctic Air.

Lubbock...

LONG TERM...
THE LONG TERM FORECAST WILL SEE CONTINUED FLUCTUATIONS IN TEMPERATURE
WITH LITTLE CHANCES OF PRECIPITATION. NEAR ZONAL FLOW WILL BE IN
PLACE ON WEDNESDAY AND THURSDAY. TEMPERATURES WILL MODERATE ON THESE
DAYS WITH WESTERLY WINDS AND ABOVE SEASONAL AVERAGE TEMPS ON
THURSDAY. A SHORT WAVE TROUGH MOVING ACROSS THE MIDDLE MISSISSIPPI
VALLEY ON THURSDAY WILL SEND A COLD FRONT THROUGH THE AREA LATE ON
THURSDAY. THE GFS IS CONTINUING ITS UNREALISTIC...SLOW
PROGRESSION OF THIS FRONT. THEREFORE HAVE SIDED MORE WITH THE NAM
AND EUROPEAN SOLUTIONS ON THE TIMING OF THIS FRONTAL PASSAGE.
SOMETHING ALL MODELS CAN AGREE UPON IS COLDER AIR FILTERING INTO
THE REGION FOR THE WEEKEND WITH NORTHWEST FLOW OVERHEAD.

MODELS DO CONTINUE TO DIVERGE ON SOLUTIONS EARLY AND MIDDLE OF NEXT
WEEK. THE LATEST EUROPEAN SOLUTION DEPICTS A COLD AIR DUMP INTO
MUCH OF THE US EARLY NEXT WEEK. THIS SOLUTION IS ALSO SUPPORTED
BY THE NAEFS MEAN. HOWEVER...MODEL SPREAD IS VERY HIGH IN THE
INDIVIDUAL ENSEMBLE MEMBERS SO FORECAST UNCERTAINTY REMAINS HIGH.
JDV

Amarillo...

WILL SEE A PERIOD OF MODERATING TEMPS WEDNESDAY AS QUASI ZONAL FLOW
DEVELOPS ALOFT. THIS WILL ENHANCE SURFACE LEE TROUGHING ACROSS THE
WESTERN HIGH PLAINS. DOWNSLOPING SOUTHWEST WINDS WILL HELP TO PUSH
TEMPS INTO THE MID TO UPPER 50S. A SHORTWAVE TROUGH WILL MOVE OUT OF
THE NORTHERN ROCKIES THURSDAY AND WILL DRAG A COLD FRONT INTO THE
AREA. SLIGHTLY COOLER AIR WILL ACCOMPANY THIS FRONT BUT TEMPS WILL
STILL CLIMB INTO THE 50S. MEDIUM RANGE MODELS CONTINUE TO SHOW AN
AMPLIFICATION OF THE UPPER PATTERN HEADING INTO THE WEEKEND WITH A
RIDGE OVER THE WESTERN CONUS. ECMWF IS MORE AGGRESSIVE WITH THE
AMOUNT OF COLD AIR THAT WILL MOVE INTO THE AREA. HAVE CONTINUED WITH
PREVIOUS FORECAST TRENDS IN SLASHING THE MEX GUIDANCE TEMPS SEVERAL
DEGREES. DRY FORECAST CONTINUES THROUGHOUT THE 7 DAY PERIOD.

CLK

Dallas/Ft Worth...

THIS WEEKEND INTO EARLY NEXT WEEK...CONCERNING THE UPPER TROUGH
DIGGING SOUTH THRU THE PLAINS ON FRIDAY...MODELS CONTINUE TO
DIFFER ON ITS EXACT PLACEMENT. THE GFS IS FURTHER EAST WITH THE
PASSAGE OF THE TROUGH GIVING US MORE OF A GLANCING BLOW OF COOL
AIR HEADED INTO THE WEEKEND WHILE THE ECMWF BRINGS THE TROUGH
RIGHT OVER NORTH TX...SENDING A CP AIRMASS INTO THE AREA. IN
GENERAL GFS IS MUCH WARMER THAN ECMWF DURING THE PERIOD. FOR
NOW...UNTIL SOME SORT OF CONSENSUS OCCURS CONTINUED THE TREND OF
UNDERCUTTING GFS GUIDANCE RATHER THAN FULLY ADOPTING THE ECMWF
NUMBERS. KEPT THE EXTENDED FORECAST DRY AS OPPORTUNITIES FOR
MOISTURE RETURN CONTINUE TO LOOK LIMITED AT THIS TIME.

CAVANAUGH

[srainhoutx]

Updated HPC Prelim Extended Disco...

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
757 AM EST TUE DEC 15 2009

VALID 12Z SAT DEC 19 2009 - 12Z TUE DEC 22 2009

A STRONG AND RETROGRADING POSITIVE ANOMALY AT HIGH LATITUDES OF
THE NORTH ATLANTIC AND CANADA FAVORS CLOSED CYCLONES UNDER ITS
BASE IN THE LOWER 40S LATITUDE. A NEGATIVE ANOMALY RETROGRADING
THROUGH ALASKA FAVORS RIDGING IN WESTERN CANADA...AND COULD ALLOW
FOR A SOUTHERN STREAM MOVING THROUGH THE SOUTHWEST LATE IN THE
PERIOD. THE MODELS AGREE ON THESE IDEAS. THE MODELS ARE SHOWING
DECREASING SPREAD IN THEIR SOLUTIONS WITH SYNOPTIC SCALE
FEATURES...THOUGH DETAIL SPREAD IN THE MID TO UPPER PATTERN FROM
THE GREAT LAKES AND MIDWEST THROUGH THE NORTHEAST IS LARGE AND THE
FORECAST THERE REMAINS MORE UNCERTAIN. CHOSE A COMPROMISE OF THE
00Z CANADIAN/00Z ECMWF BASED ON ENSEMBLE CLUSTERING OF LOW
CENTERS...AND AFTER BROWSING THE 500 HPA ENSEMBLE SPAGHETTI
DIAGRAMS USING THE 5400 METER AND 5520 METER CONTOURS.

NORTHWEST...
AS THE ECMWF AND CANADIAN HAVE ACCELERATED THIS SYSTEMS NORTHEAST
PROGRESSION SINCE THEIR SOLUTIONS FROM THIS TIME YESTERDAY...THE
MODELS ARE IN MUCH BETTER AGREEMENT ON A SYSTEM MOVING INTO THE
PACIFIC NORTHWEST EARLY NEXT WEEK. MODERATE TO HEAVY
PRECIPITATION OF SHORT DURATION IS EXPECTED WITH THIS SYSTEM AS IT
MOVES INTO THE WEST.

SOUTH AND EAST...
A FRONTAL WAVE MOVES FROM THE GULF OF MEXICO ACROSS FLORIDA INTO
THE WESTERN SUBTROPICAL ATLANTIC...BRINGING HEAVY RAINS TO THE
EASTERN GULF COAST AND SOUTHEAST. ONCE IT NEARS THE BAHAMAS...THE
00Z MULTI-MODEL ENSEMBLE MEMBERS SPLIT INTO TWO CAMPS...WITH A
SMALLER SOUTHERN CAMP COMPRISED OF ONE-THIRD OF THE MEMBERS MOVING
THE SYSTEM SOUTH OF BERMUDA WITH THE LOW WEAKENING MARKEDLY AS IT
APPROACHES THE AZORES EARLY NEXT WEEK. THE WESTERN CAMP MOVES THE
RESULTANT CYCLONE NORTHWARD OFFSHORE THE EAST COAST. DETAIL
DIFFERENCES ACROSS THE GREAT LAKES/NORTHEAST/ATLANTIC CANADA ON
THE EXPECTED LOCATION OF THE UPPER LEVEL CYCLONE CENTER KEEP THE
FORECAST SHROUDED IN UNCERTAINTY. IF A MORE WESTERN UPPER CENTER
FORMS IN THE GREAT LAKES DUE TO BUILDING POSITIVE ANOMALIES IN
CANADA...WHICH IS QUITE POSSIBLE IF NOT LIKELY...THAN THE LOW
MOVES DIRECTLY UP THE EAST COAST BRINGING HEAVY SNOWS TO THE
MID-ATLANTIC AND NEW ENGLAND STATES AND POSSIBLY BRINGS A
MILD/EASTERLY MARITIME POLAR AIR MASS INTO MAINE...WHICH WOULD
MODERATE TEMPERATURES NEXT MONDAY/TUESDAY. HOWEVER...IF THE
ENSEMBLE MEAN SOLUTIONS VERIFY...THE CYCLONE WOULD BE WHISKED WELL
OFFSHORE THE MID-ATLANTIC AND NEW ENGLAND COASTS AND SOUTHEAST OF
THE 40N 70W BENCHMARK WHICH WOULD LEAD TO MUCH LOWER SNOW TOTALS
FOR THE MID-ATLANTIC AND NEW ENGLAND STATES. THIS IDEA WOULD ALSO
KEEP NEW ENGLAND COLD UNDER THE CORE OF THE UPPER LOW. A
COMPROMISE OF THE 00Z CANADIAN/00Z ECMWF SPLITS THE UNCERTAINTY
HERE UNTIL THE MODELS AGREE ON THE EXPECTED UPPER PATTERN ACROSS
THE GREAT LAKES/NORTHEAST/ATLANTIC CANADA.

ROTH

[srainhoutx]

Morning e-mail from Jeff Lindner...I'll post it here as well as the interest in the Longer Range has some relevance in this Topic and our discussions...

Active pattern remains overhead with continued rain chances and cold weather.



Strong cold front pushing off the coast this morning with cold air advection lagging behind the main surface boundary. Dense sea fog has been forced to the coastal counties and offshore waters…and this will be pushed out to sea by increasing N winds today. Upper trough back to our west will induce another overrunning event across SE TX through early Thursday…so no sun is expected until Thursday afternoon at the earliest. This trough will force a NW Gulf surface low yet again this winter season…although this event looks to occur more over the central Gulf so impacts along the TX coast look lower than with the previous systems.



For today highs have already been reached and it is downhill from here with upstream observations showing temperatures already in the 40’s at College Station, Huntsville, and Brenham. Cold air advection, clouds, and rainfall will stunt any warming trend and temperatures will fall into the low 50’s and upper 40’s areawide this afternoon. Upper trough to the west and highly active sub-tropical jet will increase upglide over this shallow cold dome allowing showers to develop over the region. Will favor the areas along and SE of the US 59 corridor where axis of greatest moisture and pegged jet energy looks greatest.



Next system digs deep into Mexico tonight and Wednesday and crosses S TX early Thursday. Impacts appear mainly offshore, although latest GFS and WRF do show rain chances creeping back into areas S of I-10 for Wednesday into early Thursday. Will go with 50% S of IAH after a brief break this evening and early Wednesday. With thick clouds and cold air advection will see temperatures struggle in the 40’s much of Wednesday and in the 50’s through the upcoming weekend. Surface low deepens to near 1008mb over the central Gulf and this will support strong ENE to NE winds over our coastal waters with increasing seas and tides. Extra-tropical storm surge model shows tides running 1-3 feet above normal by early Thursday. While close, this should not cause any major problems and will be nothing new as tides have run at these levels many times this fall with several of these NW Gulf surface lows.



System will exit east of the area late Thursday and if everything goes as planned the sun will make a return for Friday. Upper level pattern appears to turn more NW over the weekend with a clear drying trend which should help keep skies more sunny than cloudy. Next front will be due in on Friday night as western US ridge amplifies sending another piece of cold air southward. Feel it is best to undercut the GFS numbers for the weekend and go with highs in the 50’s even with sun as the model has not done well with these shallow air masses riding down the plains.



Long range:

Models continue to hint at the idea of some significant cold moving southward the week of Christmas. The GFS has been hinting at a favorable upper air pattern along with several of its ensemble members while the ECMWF has been much more consistent in showing a very cold pattern. No doubt that the source region of this air (NW Canada) is very cold at the moment with many -30 to -40F readings in this area. Main question will be if this air mass is dislodged and if it drops southward or southeastward. For now will trend toward the ECMWF and expect to see the GFS go in that direction over the next few days but likely remaining too warm. We shall see!

[srainhoutx]

Here are the differences between the 00Z GFS and ECMWF 500mb at 168 hours...

[snow and ice]

You can see that EURO has good handle on the upper air pattern. It has progressively stronger dumps of arctic air coming down over the next 10 days. With each dump, the trough broadens and deepens. There is one shot this weekend. Then, another shot early next week. Finally, the trough broadens and deepens even more for an even colder shot.

0z EURO:
http://www.ecmwf.int/products/forecasts ... 9121500!!/

[Portastorm]

A little closer to home and in what is now becoming a disturbing trend ... our local WFO has underestimated the cold air advection (CAA) associated with this latest front. Temps in the Austin area have dropped to near 40 with mid to upper 30s to our north and west. We also have extensive cloudcover. I'll be very surprised if we even break 50 degrees today.

Technically our high could be considered 63 since it was that at midnight. But since then temps have dropped 20 degrees and continue falling.

[lrak]

Thanks for all the heads up on this possible winter event! I need some help reading the models, I've seen a few similar questions but I still don't understand the explanations The GFS shows a freezing line, but on the other models how can I tell where the freezing line is on each run. Like the model image above has numbers in the 500s, I understand the pressures (higher is closer to the ground etc.) but how do you calculate a temperature based on these pressures? Is there a formula you can post?

thanks

lrak AKA karl

[srainhoutx]

Hey Karl. Welcome to Winter Weather Season. How are the waves in Corpus and do you have your insulated wetsuit ready? Here is a good site that may help a bit. The Free ECMWF site does not show in detail the 'finer' 850mb temps etc...

http://www.meteo.psu.edu/~gadomski/ewall.html

[Portastorm]

Karl,

Generally speaking, you can consider adding 8 or 9 degrees Celsius to any 850mb temperature to get an idea (a rough idea) what the surface temperature might be. For example, the map below is what the 0z Euro run believes will exist at 6 p.m. Saturday (0z Sunday per the model). You will notice a light blue color above Corpus Christi. That shows an 850mb temperature of 0-2 degrees Celsius. So if you use the rule-of-thumb above, you get a rough surface temperature of 8 to 10 degrees Celsius. This is a surface temperature between 46 and 48 degrees at 6 p.m. Saturday in Corpus Christi. Does that make sense?

[srainhoutx]

Just an FYI, the Parallel GFS is now the GFS as of 12Z...

NCEP Operational Status Message
Tue Dec 15 15:01:21 2009 GMT

NOUS42 KWNO 151501
ADMNFD

SENIOR DUTY METEOROLOGIST NWS ADMINISTRATIVE MESSAGE
NWS NCEP CENTRAL OPERATIONS CAMP SPRINGS MD
1500Z TUE DEC 15 2009
THE 12Z NCEP MODEL PRODUCTION IS ON SCHEDULE..
THE NEW GFS/GDAS WILL IMPLEMENTED TODAY DECEMBER 15 2009 AT 12Z
PLEASE SEE THE FOLLOWING LINK FOR FURTHER INFORMATION...

$
SHRUELL/SDM/NCO/NCEP

http://www.nco.ncep.noaa.gov/pmb/nwpara/analysis/

[lrak]

http://www.ripcurl.com/index.php?hbomb

Best wetsuit in teh world

Corpus and S. Padre have awesome surf during the winter, however this winter I'm probably not going to be able to continue our tradition of surfing on Christmas day. The coldest I've ever experienced was 48F water and 40F air with NW winds. I'll never forget how much our hands hurt after thawing them out in the truck. Ice cream headaches are a bummer too, when you have to duck under the waves paddling out, the third or fouth one gives you that feeling...OUCH...sometimes you have no choice but to endure the pain until you make it out.

back to topic!

Thanks for the info and the links guys!