Texas Winter 2012-2013

[CaptinCrunch]

A multi inch rain is needed before we head into any sort of deep freeze. It will help protect the grass roots and absorb the suns rays, less heat released back into the atmosphear

[vbhoutex]

Here is today's email from Jeff Lindner about the upcoming rains:

Heavy Rainfall threat increasing for Tuesday-Wednesday.

Powerful upper level storm system currently located inland over S CA will be moving ESE into N MX over the next 24 hours. Large scale ascent developing over TX over the next 24 hours ahead of this feature will help to induce surface pressure falls across S TX. Deepening surface low pressure over S TX will start to bring a warm front northward with this feature situated from near Port Lavaca to Bay City and then ESE into the northern Gulf of Mexico by early Tuesday. Strong 850mb low level jet will rapidly return moisture over the top of the warm front and surface cool dome resulting in the formation of light rainfall by late tonight. As large scale lift increases on Tuesday expect thunderstorms to develop along the warm front. Expect very heavy rainfall in these storms along with widespread rainfall north of the boundary to help hold the boundary roughly in place between I-10 and the coast for much of Tuesday into Tuesday night.

As the upper level storm ejects ENE to NE across TX on Wednesday a slow moving cool front/dry line will punch eastward into the area. While some of the models have begun to diverge some with respect to rainfall potential on Wednesday, feel that good upper level divergence on the eastern side of the upper level storm coupled with a slow moving frontal boundary will continue to produce heavy thunderstorms. Dry slot could impede development to some degree, but this feature looks aimed more at central TX than SE TX.

Heavy Rainfall:

Main threat with this event will be very heavy rainfall. Models continue to show PWS climbing to over 1.7 inches which is about .25 of an inch above the +2SD for this time of year and very near the “maximum” values for early January. GPS loops of PWS over the Gulf of Mexico do suggest an area of 1.8-2.0 inch values located over the Bay of Campeche and this plume of deep moisture should become ingested into the storm system and brought northward into the area by late Tuesday. While such moisture is commonplace in the summer, it is rare in the winter when storm systems and dynamics are much stronger. The combination of such high moisture levels and strong dynamics will produce some very heavy rainfall. The air column is nearly saturated from the surface through the mid levels which will support efficient rainfall production with little evaporation leading to high short term rainfall totals. Moisture of this magnitude will support hourly rainfall totals of 1-2.5 inches.

Flash Flood Guidance across the region is lowest along and SE of US 59 where rains have been plentiful of late. 3-hr flash flood guidance is running around 3.0 inches. Suspect the axis of heaviest rainfall will be along and SE of US 59 (or just north of the warm frontal boundary) at least on Tuesday night. It is likely that flash flood guidance will be exceeded and significant run-off generated in this region. Rises on area bayous, creeks, and rivers is likely. Street flooding will be likely especially under areas of persistent cell training.

Severe Threat:

Not overly confident in a significant severe weather threat will this system as instability appears to be generally lacking south of the warm front due to widespread clouds and rainfall. Low level wind shear will be more than sufficient for storm rotation with ESE surface winds under stronger WSW mid level flow. Main threats will be wind damage and isolated tornadoes. Should the instability be slightly greater than forecast, the tornado threat would increase over the are Tuesday night and Wednesday.

Extended:

Much focus on the short term, but the extended does bring another wet looking system into the area by the weekend followed by a strong cold front early Sunday. Appears rains may continue after the cold front Sun-Mon. Will need to keep an eye on low temperatures by Tuesday AM if moisture is still lingering.

Severe Weather Outlook (Wednesday):
http://www.spc.noaa.gov/products/outloo ... k_0830.gif

Our local OCMs are all also talking about this, not just for SE TX but for the whole state. Could be a real drought denter/buster for some areas. Also still hearing talk of the upcoming cold and possible Winter precip, even in SE TX.

[dhweather]

I really hope that we all get a lot of rain out of this. The prospects of 3-4 inches widespread is good for everyone in Texas. Many lakes are low, we need the rain, badly.


Lake Lavon is 60% full - down 9.4 feet - that's the source of a lot of the drinking water in Dallas.

Statewide, Monitored Water Supply Reservoirs are 65.44% full on 2013-01-07

It's not as bad as 2006, but if we don't get some rain, we will be there this summer.

[weatherdude1108]

Talk on a blog of the local weather station here in Austin about it. We need the rain desperately! I saw a report that our lakes (Austin's water source Lakes Travis and Buchanan) have about two years worth of water if conditions continue. Not sure if true. They are at 41% capacity now. Austin had ZERO rain in November, not much in December. Camp Mabry and the Airport received 0.31 and 0.83 respectively in December. Here's to reversing the trend in the next couple days, and bringing in some Winter mix fun later!

http://blogs.kxan.com/2013/01/07/major-mid-week-storm/

[opticsguy]

It looks like TX is about to receive several cubic miles of rainfall. That should help fill up the lakes.

Upper Stratosphere question: Could a burst of cosmic rays or solar x-rays warm up the 10 mb level and cause such a spike?

[Ntxw]

A little summary to see what we're looking at today

Medium range

As most of us probably know in the coming days a compact, potent system will effect much if not all of Texas. HPC paints several inches of rain over the state with the core being in east and southeast Texas. Unlike systems we have seen this will be a mild storm with little or no cold air attachment. That means after it's passage moist flow will continue in the state as the southeast ridge continues it's dominance (very important player in the longer run) setting stage for the upcoming weekend.



Starting next weekend a Colorado low will swing through the central plains. It will renew the snow cover to our north and drive down our first polar front. There is timing issues between the models in the following system that will ride this front. A storm will emerge from the southwest and cut through Texas into the midwest. It will most likely have to turn north in Texas (negative tilt) due to the presence of the strong SE ridge.

Early model runs have shown that this system will have yet another baroclinic instability set up. That means a trowal/comma head will likely provide wind whipped snow on it's backside somewhere in the southern plains with strong hp to the north and surface low to the south. Again timing is different on the models so we will see 13+- is my guess right now. After wards we will likely usher in cold air not that different than Christmas.

Long Range

Pattern set up on the models overall has not wavered much. Run per run may seem different but overall the idea is the same. Strong -EPO/AO block will occur and set stage for arctic air intrusions. People seem to be confused assuming we have been calling for cold blasts to end the world. The models have not (yet) shown any kind of intense cold in Texas. We have been saying at 500mb the pattern set up is unusual and has the potential to deliver mighty cold air. The eastern 1/3rd of the country and southeast is under the influence of the strong SE ridge. That may prevent cold air from invading that region until the high is beaten down which may take longer than in the plains and west and so I've been wary about believing their call for a strong -NAO block. Better understanding of the what will happen second half of this month will probably come next weekend.

[dhweather]

I think this is worth repeating again:

The models have not (yet) shown any kind of intense cold in Texas. We have been saying at 500mb the pattern set up is unusual and has the potential to deliver mighty cold air.

[orangeblood]

GFS ensemble trend has been troubling....beats up the Alaskan ridge and thus weakens the negative EPO, which is key for sustained cold in the southern plains

[Ntxw]

GFS ensemble trend has been troubling....beats up the Alaskan ridge and thus weakens the negative EPO, which is key for sustained cold in the southern plains

I wouldn't be too worried about them right now. There is a lot of spread amongst them, some try to plow the Aleutian low into the block (not likely to happen). It will most likely be stationary and continue to pump up the ridge with the MJO heading into phases 6-7, and heat flux will feed the NE Pac ridge from the tropics.

Which by the way this MJO wave is the real deal. Very strong convection associated with it and 3-4 SD's above normal

[orangeblood]

GFS ensemble trend has been troubling....beats up the Alaskan ridge and thus weakens the negative EPO, which is key for sustained cold in the southern plains

I wouldn't be too worried about them right now. There is a lot of spread amongst them, some try to plow the Aleutian low into the block (not likely to happen). It will most likely be stationary and continue to pump up the ridge with the MJO heading into phases 6-7, and heat flux will feed the NE Pac ridge from the tropics.

Just noticed that they've been very consistent with the upper air pattern over the past few days until the past 3 runs, starting last night. Trying to figure out what the problem is....it could be the MJO or the SSW they're having trouble with??

[Ntxw]

Just noticed that they've been very consistent with the upper air pattern over the past few days until the past 3 runs, starting last night. Trying to figure out what the problem is....it could be the MJO or the SSW they're having trouble with??

It's the PNA and NAO. They keep trying to pop it positive (PNA) and -NAO, shifting everything slightly east

[HockeyTx82]

Just noticed that they've been very consistent with the upper air pattern over the past few days until the past 3 runs, starting last night. Trying to figure out what the problem is....it could be the MJO or the SSW they're having trouble with??

It's the PNA and NAO. They keep trying to pop it positive (PNA) and -NAO, shifting everything slightly east

So mother nature has East Coast Bias as well?

[Portastorm]

HPC feeling good about the large-scale, full latitude trough developing over the central part of the CONUS by late this coming weekend.

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
1026 AM EST MON JAN 07 2013

VALID 12Z THU JAN 10 2013 - 12Z MON JAN 14 2013

THE 7/00Z ECMWF/GEFS ENSEMBLE MEANS WERE IN REASONABLE AGREEMENT
THROUGH DAY 7...WITH AN AMPLIFYING RIDGE ALONG 130W-140W (IN THE
EAST PAC). AND AN AMPLIFYING TROUGH OVER THE CENTRAL PORTION OF
THE NORTH AMERICAN CONTINENT BY DAY 7.

THE FORECAST CHALLENGE AND TROUGH AMPLIFICATION STARTS
CONTENTIOUSLY WITH A DAY3-4 SYSTEM/CYCLONE IN THE SOUTHERN PLAINS
MIGRATING NORTH-NORTHEASTWARD THROUGH THE MIDWEST. A 'KICKER'
SHORTWAVE ORIGINATING IN THE EAST PAC AND COLD FRONT
STARTS/FINISHES THE PROCESS OF AMPLIFICATION ON DAY 5/6 OVER THE
CENTRAL PLAINS WITH ADDITIONAL EMBEDDED H5 ENERGY CONTINUING TO
CARVE THE WESTERN (UPWIND) PORTION OF THE TROUGH (DAYS 6/7) ACROSS
THE INTERMOUNTAIN WEST/CENTRAL ROCKIES. FOR THE MOST PART...THE
SURFACE AND H5 GRAPHICS UTILIZED SOME OPERATIONAL ASPECTS OF THE
7/00Z GFS/ECMWF DETERMINISTIC RUNS...THOUGH CONFIDENCE IS ON THE
LOW SIDE REGARDING THE DEVELOPMENT/INTENSIFICATION AND TRACK OF A
MID-LEVEL SHORTWAVE EXITING THE CENTRAL ROCKIES ON FRI NIGHT/SAT
MORNING. THIS SHORTWAVE SHOULD DEVELOP A CLOSED SURFACE CYCLONE IN
THE NORTH CENTRAL PLAINS/UPPER MISSISSIPPI VALLEY (ALONG THE
DOWNWIND SIDE OF THE TROUGH AXIS) ON SATURDAY AND SATURDAY NIGHT.

THIS BODES WELL FOR A DECIDEDLY WARMER/MILDER AND MOISTURE-LADEN
AIRMASS TO SET UP ACROSS NEW ENGLAND...THE MID ATLANTIC STATES
(DAY 4-7) AND EASTERN GREAT LAKES/MID-UPPER OHIO VALLEY (DAY 4-5).
AND THE RETURN OF COLDER CANADIAN AIR TO THE PACIFIC
NORTHWEST...GREAT BASIN...NORTHERN ROCKIES AND NORTHERN PLAINS
THROUGH DAY 6.

VOJTESAK

[HockeyTx82]

HPC feeling good about the large-scale, full latitude trough developing over the central part of the CONUS by late this coming weekend.

Please forgive my ignorance, but what does this mean for us? Down in Texas?

Are things still a go for some colder air to make it way down and perhaps set the stage for some Arctic air later on?

[Portastorm]

HPC feeling good about the large-scale, full latitude trough developing over the central part of the CONUS by late this coming weekend.

Please forgive my ignorance, but what does this mean for us? Down in Texas?

Are things still a go for some colder air to make it way down and perhaps set the stage for some Arctic air later on?

Yes, colder air will make it down into Texas this coming weekend. Also based on what I saw from the Euro, a winter storm for early next week for parts of Texas wouldn't surprise me in the least. I think orangeblood or Ntxw has been talking about this.

Arctic air? Dunno. Still too far out for certain for my tastes.

[Rgv20]

Hold on let me check the calender.....yes its January!


SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BROWNSVILLE TX
301 PM CST MON JAN 7 2013

TXZ248>257-080315-
ZAPATA-JIM HOGG-BROOKS-KENEDY-STARR-HIDALGO-INLAND WILLACY-
INLAND CAMERON-COASTAL WILLACY-COASTAL CAMERON-
INCLUDING THE CITIES OF...ZAPATA...HEBBRONVILLE...FALFURRIAS...
SARITA...RIO GRANDE CITY...ROMA...MCALLEN...EDINBURG...PHARR...
MISSION...WESLACO...RAYMONDVILLE...BROWNSVILLE...HARLINGEN...
PORT MANSFIELD...PORT ISABEL...SOUTH PADRE ISLAND...
LAGUNA HEIGHTS...LAGUNA VISTA
301 PM CST MON JAN 7 2013

...RISK FOR SEVERE THUNDERSTORMS TUESDAY NIGHT INTO WEDNESDAY MORNING...

CONDITIONS ARE EXPECTED TO BECOME FAVORABLE LATE TUESDAY INTO
WEDNESDAY MORNING FOR THE DEVELOPMENT OF THUNDERSTORMS ACROSS
PORTIONS OF DEEP SOUTH TEXAS. SOME OF THESE STORMS MAY BECOME
SEVERE.

AT THIS POINT IN TIME THE HIGHEST RISK FOR SEVERE WEATHER
EXISTS ACROSS ZAPATA...BROOKS...STARR...JIM HOGG...AND KENEDY
COUNTIES. THE MOST LIKELY TIME FOR SEVERE WEATHER IN THESE AREAS
WOULD BE BETWEEN 6 PM TUESDAY AND 3 AM WEDNESDAY. TORNADOES AND
DAMAGING WINDS ARE THE MAIN THREAT...WITH SOME HAIL OF UP TO
QUARTER SIZE POSSIBLE.

STORMS ARE EXPECTED TO FORM A LINE THAT WILL MOVE EAST INCREASING
THE SEVERE WEATHER POTENTIAL BETWEEN 9PM AND 3AM FOR WESTERN
PORTIONS OF THE RIO GRANDE VALLEY...AND INTO THE LOWER VALLEY
BETWEEN MIDNIGHT AND 6AM. DAMAGING WINDS OF 60 TO 70 MPH WOULD BE
THE MAIN THREAT WITH THESE STORMS WITH ISOLATED TORNADOES ALSO
POSSIBLE IN STRONGER CELLS. SOME CHANGES TO THE TIMING IS POSSIBLE
AND THERE IS SOME UNCERTAINTY AS TO HOW FAR EAST SEVERE STORMS
WILL TRACK.

RESIDENTS OF DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY ARE URGED
TO MONITOR THIS DEVELOPING WEATHER SITUATION AND BE PREPARED TO
TAKE ACTION IF SEVERE WEATHER THREATENS. THE AVERAGE LEAD TIME FOR
A TORNADO WARNING IS ONLY 13 MINUTES FROM THE TIME THE WARNING IS
ISSUED UNTIL DAMAGE OCCURS AND IS OFTEN MUCH LESS...SO ACT QUICKLY
IF A WARNING IS ISSUED OR SEVERE WEATHER THREATENS. RESIDENTS OF
MOBILE HOMES OR LESSER CONSTRUCTED BUILDINGS SHOULD PAY PARTICULAR
ATTENTION AND BE PREPARED TO FIND STRONGER SHELTER.

[dhweather]

A deep trough over the central US is a piece of the puzzle to get some serious arctic air intrusion. There are a lot of things that have to happen in order to get arctic air in Texas, but this is one of them.

Strong high pressure in the Eastern Pacific is another piece of the puzzle.

[Snowman67]

Snippet from this afternoon's NWS Houston discussion:

TAKING A LOOK AT THE EXTENDED FORECAST THE MODELS CONTINUE TO SHOW
AMPLIFIED UPPER LEVEL PATTERNS WITH A STRONG UPPER RIDGE ACROSS
THE WEST COAST OF THE UNITED STATES AND TROUGHING ACROSS THE
PLAINS. OF INTEREST IS THE STRENGTHENING OF THE MJO OVER THE LAST
SEVERAL DAYS AS IT MOVES FROM PHASE 4 TO PHASE 5...AS STRONG PHASE
5 (AND PHASE 2) MJO EVENTS HAVE SHOWN SOME CONNECTION TO COLD AIR
OUTBREAKS ACROSS TEXAS SOME TWO TO THREE WEEKS LATER. 38

[CaptinCrunch]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
357 PM CST MON JAN 7 2013

.DISCUSSION...
HEAVY RAINFALL EVENT EXPECTED ACROSS NORTH TEXAS BEGINNING
TOMORROW AND CONTINUING THROUGH WEDNESDAY.

HIGH CLOUDS INCREASING ACROSS THE REGION ARE INDICATIVE OF CHANGES
ON THE WAY. WATER VAPOR IMAGERY SHOWS THE POWERFUL UPPER LOW
SPINNING OVER FAR NORTHWEST MEXICO THIS AFTERNOON. THIS SYSTEM
STILL HAS A SIGNIFICANT AMOUNT OF COLD ADVECTION ON THE BACK SIDE
OF IT INDICATING THAT IT SHOULD CONTINUE DIGGING SOUTH INTO NORTH
CENTRAL MEXICO. MODELS APPEAR TO HAVE A GOOD HANDLE ON THIS AND
RAPIDLY EJECT THE SYSTEM NORTHWARD ACROSS NORTH TEXAS WEDNESDAY.
IN THE MEANTIME...CLOUD COVER WILL GRADUALLY THICKEN AND LOWER AS
LOW LEVEL WARM ADVECTION GETS CRANKING TONIGHT. A LARGE AREA OF
SHOWERS AND ISOLATED THUNDERSTORMS SHOULD DEVELOP ACROSS DEEP
SOUTH TEXAS INTO THE HILL COUNTRY AFTER MIDNIGHT TONIGHT AND
SPREAD NORTH BY EARLY TUESDAY MORNING. AREAL COVERAGE OF
PRECIPITATION WILL INCREASE THROUGHOUT THE DAY AS DEEP GULF
MOISTURE ADVECTS NORTHWARD WITH WARM CONVEYOR BELT BECOMING WELL
ESTABLISHED ON THE EAST SIDE OF THE UPPER LOW. HEAVIEST RAINFALL
AMOUNTS ARE EXPECTED TOMORROW NIGHT INTO WEDNESDAY AS LARGE SCALE
FORCING INCREASES SIGNIFICANTLY.

GIVEN THE STRENGTH OF THE WARM ADVECTION...AVAILABLE MOISTURE AND
OPTIMAL PATH ACROSS NORTH TEXAS...WIDESPREAD HEAVY RAINFALL IS
EXPECTED ACROSS NORTH TEXAS. THE HEAVIEST RAINS SHOULD BE IN THE
SOUTHEAST COUNTIES WHERE 4 INCH TOTALS ARE LIKELY THROUGH EARLY
THURSDAY MORNING. WIDESPREAD 2 TO 4 INCH TOTALS ARE EXPECTED
ACROSS THE REST OF NORTH TEXAS. AT THIS TIME...NO FLOOD WATCHES
ARE EXPECTED AS RAINS ARE EXPECTED TO BE SPREAD OUT OVER RATHER
LONG DURATION AND FLASH FLOOD GUIDANCE IS HIGH. FLOODING OF
TYPICAL LOW LYING AREAS WILL BE LIKELY.

THIS IS A VERY DYNAMIC SYSTEM WITH STRONG WIND FIELDS SO THE
THREAT FOR SEVERE WEATHER HAS BEEN A CONCERN. LATEST FORECAST
CONTINUES TO BE HEAVILY WEIGHTED TO THE HIGH RESOLUTION GUIDANCE
WHICH DEVELOPS A SURFACE LOW IN SOUTH CENTRAL TEXAS AND MOVES IT
NORTH-NORTHEAST THROUGH WEDNESDAY. THIS WOULD PLACE THE WARM FRONT
AND ASSOCIATED WARM SECTOR ACROSS OUR VERY FAR SOUTHEAST COUNTIES
WEDNESDAY AFTERNOON. MOST OF THE AREA WILL REMAIN IN THE COOLER
MORE STABLE AIR WHICH GETS REINFORCED BY STRONG NORTH-NORTHEAST
WINDS. FOR NOW...THINK THAT ANY SEVERE WEATHER WOULD BE CONFINED
TO THE FAR SOUTHEAST COUNTIES WEDNESDAY AFTERNOON. GIVEN THE
STRONG WIND FIELDS...THE LINEAR STORM STRUCTURE EXPECTED ACROSS
CENTRAL TEXAS... AND LACK OF ANY SUBSTANTIAL SURFACE BASED
INSTABILITY...THINK DAMAGING WINDS WOULD BE THE PRIMARY SEVERE
WEATHER THREAT IN THE SOUTHEAST. IF MORE INSTABILITY BECOMES
AVAILABLE WEDNESDAY AFTERNOON AND CONVECTION CAN REMAIN DISCRETE
THEN THE TORNADO THREAT WOULD BE SIGNIFICANTLY HIGHER.

PRECIPITATION WILL END BY EARLY THURSDAY ACROSS THE REGION AND
ALTHOUGH IT WILL BE DRIER...THERE WILL NOT BE ANY SUBSTANTIAL
TEMPERATURE CHANGE BEHIND THIS SYSTEM. WE REMAIN IN AN ACTIVE
PATTERN AND ANOTHER STRONG UPPER TROUGH DIGS INTO THE WESTERN US
LATE THURSDAY. THE MODEL GUIDANCE IS HAVING A LITTLE MORE TROUBLE
HANDLING THE EVOLUTION OF THIS UPPER TROUGH THROUGH THE WEEKEND
ALTHOUGH THEY ARE IN AGREEMENT WITH SENDING A STRONG COLD FRONT
THROUGH NORTH TEXAS ON SATURDAY. THE DISCREPANCIES COME AFTER THE
COLD AIR SETTLES IN PLACE ACROSS THE REGION. THE OPERATIONAL GFS
CONTINUES TO DETACH A PIECE OF ENERGY FROM THE MAIN TROUGH WHICH
MOVES THROUGH THE UPPER MIDWEST LATE SATURDAY. THIS STRONG VORT
MAX AND ITS ASSOCIATED LIFT COMES ACROSS NORTH TEXAS ON SUNDAY.
THE ECMWF DOES SHOW THIS SCENARIO...ALTHOUGH SIGNIFICANTLY WEAKER.
IT IS ALSO CONSIDERABLY WARMER. WITH THE GFS ENSEMBLES BEING QUITE
SPREAD OUT AND LITTLE CONSENSUS AMONG OPERATIONAL GUIDANCE...WILL
KEEP THE FORECAST COLD AND DRY FOR SUNDAY. THIS SYSTEM WILL BE
MONITORED CLOSELY OVER THE NEXT COUPLE OF DAYS...AS IT WOULD BE
FAVORABLE FOR WINTRY PRECIPITATION.

[Comanche]

Are the euro weeklies out yet, and has anyone seen them??