October 2015 - Severe Storms/Moderate Risk Excessive Rainfal

[srainhoutx]

Jack Beven offering a bit of insight to what some of the guidance suggested regarding Patricia remnants developing in the NW Gulf...

TROPICAL STORM PATRICIA DISCUSSION NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL EP202015
1000 AM CDT WED OCT 21 2015

Conventional and microwave satellite data show that Patricia
remains poorly organized. The low-level circulation is elongated
from north to south, and there is little evidence of a tight inner
core. While the convection is vigorous, it is occurring mainly in
an almost linear area west and south of the center. The latest
satellite intensity estimates are unchanged since the previous
advisory, so the initial intensity remains 35 kt.

Patricia is moving faster toward the west with an initial motion of
270/10. There is no change to the track forecast philosophy. The
tropical cyclone is expected to initially move westward to
west-northwestward on the south side of a low- to mid-level ridge
over the Gulf of Mexico. After about 24 hours, Patricia is expected
to turn northwestward and northward between the ridge and a deep-
layer trough over northwestern Mexico and the adjacent northeastern
Pacific. The model guidance is in excellent agreement with this
scenario and forecasts landfall along the coast of southwestern
Mexico between 48-72 hours. The new forecast track is similar to,
but a little faster than, the previous track, and it lies in the
middle of the tightly clustered track guidance.

Continued light shear and warm sea surface temperatures are
favorable conditions for Patricia to strengthen if the storm can
overcome its current disorganized condition. Based on the premise
that this will happen, the intensity forecast is identical to that
of the previous advisory in calling for the cyclone to become a
hurricane in about 36 hours and continue strengthening through
landfall. Several of the guidance models forecast a higher peak
intensity than the official, and rapid intensification remains a
possibility given the favorable environment. After landfall,
Patricia should quickly weaken and dissipate over the mountains of
western Mexico.

There are no changes to the watches for the coast of Mexico at this
time. Warnings my be required for portions of the watch area later
today or tonight.

It should be noted that several of the global models develop a low
pressure area over the northwestern Gulf of Mexico in four to five
days. At this time, it appears that this system will be a
non-tropical low that absorbs the remnants and moisture of Patricia
moving northeastward across Mexico.

FORECAST POSITIONS AND MAX WINDS

INIT 21/1500Z 12.9N 97.5W 35 KT 40 MPH
12H 22/0000Z 13.4N 99.1W 40 KT 45 MPH
24H 22/1200Z 14.5N 101.3W 50 KT 60 MPH
36H 23/0000Z 15.7N 103.1W 65 KT 75 MPH
48H 23/1200Z 17.3N 103.8W 80 KT 90 MPH
72H 24/1200Z 21.5N 104.0W 45 KT 50 MPH...INLAND
96H 25/1200Z...DISSIPATED

$$
Forecaster Beven

[DoctorMu]

This is now officially a weekend event. The SE Ridge hanging on and iso to scattered showers through Friday are most of what is expected.

The mid and high level moisture from Patricia will feed the trough. The SJT will be relatively weak - nothing like '94 or Joaquin firehouse (once in a 1000 year event)

PREV DISCUSSION... /ISSUED 438 AM CDT WED OCT 21 2015/

DISCUSSION...
A BIG RAIN EVENT IS STILL EXPECTED TO AFFECT SOUTHEAST TEXAS AT
THE END OF THIS WEEK. HOWEVER...FOR TODAY...THURSDAY...AND FRIDAY
THERE WILL BE A STRUGGLE BETWEEN THE APPROACHING SYSTEM AND A LOW
TO MID LEVEL HIGH PRESSURE RIDGE JUST EAST OF THE STATE. AT 00Z
/7PM CDT/ LAST EVENING...AN ANALYSIS OF THE UPPER AIR LEVELS
SHOWED HIGH PRESSURE CENTERED OVER THE SOUTHEASTERN GULF OF MEXICO
AT 500 MB...SOUTHERN GA AT 700 MB...AND JUST EAST OF NC AT 850 MB.
THE RIDGE EXTENDED INTO SE TEXAS AT EACH LEVEL. THE DEEP LEVEL
UPPER LEVEL LOW WAS OVER NM WITH DEEP LAYER MOISTURE ACROSS WEST
TEXAS AND THE PANHANDLE. THE WATER VAPOR ALSO SHOWED ANOTHER AREA
OF MID LEVEL MOISTURE MOVING NORTHEASTWARD FROM THE PACIFIC ACROSS
MEXICO AND TOWARD SOUTH TEXAS. THIS MOISTURE APPEARED TO BE
PARTIALLY TAPPED INTO TROPICAL STORM PATRICIA JUST SOUTH OF FAR
SOUTHERN MEXICO.

A CONSENSUS OF THE MODELS HAS LESS CHANCES OF RAIN OVER THE
FORECAST AREA TODAY THROUGH FRIDAY. THIS IS DUE MAINLY TO THE FACT
THAT THE RIDGE WILL SLOWLY RETREAT EASTWARD AS THE UPPER LEVEL
SYSTEM SHEARS OUT AS IT MOVES NORTHEASTWARD ACROSS THE ROCKIES
INTO THE PLAINS. THE MAJORITY OF THE MOISTURE ASSOCIATED WITH THIS
SYSTEM IS FORECAST BY THE MODELS TO STAY MORE OVER THE SOUTHERN
AND CENTRAL PARTS OF THE STATE. THE TROPICAL MOISTURE MOVING
NORTHWARD FROM THE PACIFIC WILL AID IN KEEPING SOME POPS IN
PLACE...HOWEVER DEEPER LAYER MOISTURE FROM PATRICIA SOUTH OF
MEXICO WILL PROBABLY NOT ARRIVE UNTIL FRIDAY NIGHT OR SATURDAY
MORNING. THIS SHOULD BE THE CATALYST FOR THE MORE WIDESPREAD
RAINFALL EVENT FORECAST BY THE MODELS THAT HAS THE POTENTIAL FOR
HEAVY RAINFALL ON SATURDAY AND SUNDAY.

FOR THIS FORECAST KEPT HIGHER CHANCES FOR RAIN AND THUNDERSTORMS
OVER THE SOUTHERN AND WESTERN COUNTIES THROUGH FRIDAY. ALTHOUGH
WENT WITH POPS OF 50 TO 60 PERCENT ON THURSDAY AND FRIDAY...WILL
NOT BE SURPRISED IF LESS COVERAGE OCCURS. SOME LOCATIONS OVER THE
EASTERN HALF OF THE FORECAST AREA MAY ONLY SEE ISOLATED SHOWERS OR
THUNDERSTORMS TODAY AND FRIDAY...WITH THURSDAY HAVING THE BEST
CHANCES AS A SLUG OF MOISTURE WITH PW/S REACHING TO AROUND 2
INCHES MOVES OVER THE COASTAL AREAS AND WESTERN COUNTIES.

OVER THE WEEKEND...THE MOISTURE MOVING UP FROM THE SOUTH WILL FEED
INTO A DEVELOPING COASTAL TROUGH WITH INSTABILITY FURTHER PROVIDED
A COUPLE OF STRONG UPPER LEVEL SHORTWAVE TROUGHS THAT WILL MOVE
OVERHEAD BOTH SATURDAY AND SUNDAY. THE GFS FORECASTS PW/S TO REACH
FROM 2.0 TO 2.4 INCHES OVER PORTIONS OF THE AREA ON SATURDAY AND
SUNDAY.

LINGERING CHANCES FOR RAIN WILL CONTINUE INTO BOTH MONDAY AND
TUESDAY AS BOTH THE GFS AND ECWMF KEEP THE COASTAL SYSTEM IN PLACE
OVER THE NORTHWESTERN GULF BOTH DAYS.

[Katdaddy]

From this mornings Hou-Gal late morning disco:

LOOKING AHEAD...SATELLITE IMAGERY IS SHOWING A LARGE SWATH OF MUCH
DEEPER TROPICAL MOISTURE IN THE WESTERN GULF WATERS HEADING TO THE
WEST AND NORTHWEST TOWARD THE TEXAS COAST WHICH SHOULD GIVE PARTS
OF OUR AREA A PRETTY GOOD SHOT OF RAIN LATER TONIGHT AND ON INTO
TOMORROW. WILL WAIT FOR ALL OF THE 12Z MODEL DATA TO ARRIVE BEFORE
MAKING THE CHANGES...BUT ANTICIPATE CARRYING HIGHER RAIN CHANCES
FOR LATER TONIGHT AND FOR TOMORROW.

[srainhoutx]

Definitely seeing an surge of moisture heading toward the Texas Coast including SE Texas out in the Gulf. Also, an early look at the 12Z GFS suggests good voticity at the 700mb level as well as a Coastal Low organizing between Brownsville and Corpus. That bodes well for heavier rainfall and the potential of isolated stronger storms Saturday into Sunday. There should also be some enhanced lift as a 500mb short wave moves across N Texas during that timeframe.

10212015 12Z GFS f96.gif

10212015 12Z GFS f102.gif

10212015 12Z GFS f120.gif

[unome]

Bay of Campeche's looking pretty interesting

http://earth.nullschool.net/#current/wi ... 23.90,1235

https://www.windyty.com/?clouds,30.221,-89.912,4

[srainhoutx]

Rainfall totals via the GFS through 144 hours:

10212015 12Z GFS 144 gfs_apcpn_scus_24.png

The Canadian keeps the rain falling into next Wednesday and therefore has much higher totals through hour 192:

10212015 12Z Canadian gem_apcpn_scus_32.png

[srainhoutx]

Starting to see some agreement with the Global models. The 12Z Euro also is suggesting the heavy rainfall potential looks legitimate. All the guidance develop a Coastal low during the weekend and include a lot of mesoscale features from the embedded disturbances crossing Texas and point N and E. The guidance is slowly increasing the chances that tomorrow throughout the weekend and possibly into next Monday could be very wet with rainfall amounts ranging from the 4 to 6 inch range with isolated totals potentially exceeding 10 inches where the heavier storms set up and the possibility of train heavy rainfall rates.

[Texaspirate11]

Someones gonna get smacked.....

[stormlover]

i wouldn't go by that pirate, Models today are coming in a better agreement now that houston area and Beaumont area could get tons of rain

[Texaspirate11]

Oh we'll see some good stuff.
Just want the disability community in those areas to be prepared and
get their evacuation plans ready if need be.................

[stormlover]

no doubt!!!

[Texaspirate11]

The community must be aware and prepared.

[srainhoutx]

The Weather Prediction Center is Updating their afternoon QPF, so that graphic may have some merit...

[Texaspirate11]

The Weather Prediction Center is Updating their afternoon QPF, so that graphic may have some merit...

I'm taking this really seriously.....thanks Srainhoutx.

[Andrew]

I am really concerned along a NE to SW axis centered over the DFW region. GFS continues to paint that area with a multiple day training event. 2 inch Pwats associated with a deep moisture fetch from both Patricia and the gulf along with a series of shortwaves rotating though. This adds up to a classic training event. Closer to home, the designation of a coastal low looks more likely, but again it is all about location, location, location. Could see a strong gradient between the coastal low and the trough centered over North Texas. If that is the case, I would suspect the WPC's QPF map will be fairly accurate.

[ticka1]

Time to watch realtime and see how the players of this weather event are interacting with our local weather. I am cautious with the model runs - just be prepared and turn around don't drown.

[srainhoutx]

5 Day Rainfall Totals Graphics just issued by NWS San Antonio/Austin.

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
308 PM CDT WED OCT 21 2015

TXZ171>173-183>194-202>209-217>225-228-222015-
LLANO-BURNET-WILLIAMSON-VAL VERDE-EDWARDS-REAL-KERR-BANDERA-
GILLESPIE-KENDALL-BLANCO-HAYS-TRAVIS-BASTROP-LEE-KINNEY-UVALDE-
MEDINA-BEXAR-COMAL-GUADALUPE-CALDWELL-FAYETTE-MAVERICK-ZAVALA-
FRIO-ATASCOSA-WILSON-KARNES-GONZALES-DE WITT-LAVACA-DIMMIT-
308 PM CDT WED OCT 21 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL TEXAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON AND EVENING. THERE IS A MARGINAL RISK SOME STORMS COULD
BECOME STRONG TO SEVERE WEST OF A KERRVILLE TO PEARSALL LINE...
PRODUCING WIND GUSTS UP TO 60 MPH AND HAIL UP TO QUARTER SIZED.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

SCATTERED TO NUMEROUS SHOWERS AND STORMS ARE POSSIBLE THURSDAY
THROUGH FRIDAY. THERE IS A MARGINAL RISK SOME STORMS COULD BECOME
STRONG TO SEVERE ALONG AND WEST INTERSTATE 35...PRODUCING WIND
GUSTS UP TO 60 MPH AND HAIL UP TO QUARTER SIZED.

NUMEROUS SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE FRIDAY NIGHT
THROUGH SATURDAY NIGHT. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE
ANYTIME THURSDAY THROUGH SATURDAY NIGHT...LEADING TO FLASH
FLOODING.

THE GREATEST AREAS AT RISK FOR LOCALLY HEAVY RAINFALL AND FLASH
FLOODING WILL BE ACROSS THE EASTERN HILL COUNTRY AND ANYWHERE
ALONG AND EAST OF INTERSTATE 35. BETWEEN 4 AND 7 INCHES OF RAIN
ARE EXPECTED TODAY THROUGH SUNDAY ACROSS THIS REGION...WITH
ISOLATED POCKETS OF 8 TO 10 INCHES. THE GREATEST CHANCES FOR
LOCALLY HEAVY RAINFALL WILL BE THURSDAY NIGHT THROUGH FRIDAY AND
THEN AGAIN LATE FRIDAY NIGHT THROUGH SATURDAY. FLASH FLOOD WATCHES
WILL LIKELY BE REQUIRED.

FARTHER WEST...BETWEEN 2 AND 4 INCHES OF RAIN IS POSSIBLE ACROSS
THE WESTERN HILL COUNTRY AND RIO GRANDE.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE URGED TO SUBMIT REPORTS OF HEAVY RAINFALL AMOUNTS
AND ANY FLOODING.

[srainhoutx]

Updated Day 4 to and Day 6 to 7 QPF is finally out.

[srainhoutx]

And finally the Updated 7 Day QPF...impressive totals folks. Keep eye on the weather and make sure those that are not weather wise are aware of this developing situation throughout the weekend.

[DoctorMu]

Major PW juice lurking offshore with tongue ready to lap between Corpus and Palacios