March: Warm Days To End The Month With Isolated Showers

[djjordan]

Looking at some of the models with this squall line developing...... Wondering if SE Texas is going to see a widespread derecho event?

Only inhibiting factor I see is that the line won't move terribly fast but the winds are already very strong and the strength of the squall line could very well produce damage. IMO

[Ptarmigan]

Looking at some of the models with this squall line developing...... Wondering if SE Texas is going to see a widespread derecho event?

It could be possible. Frankly, I would not be surprised it happens. It rarely happens. I can think of some off my head; 1986, 1989, and possibly May 10, 1999 storm.

May 17, 1986
http://www.spc.noaa.gov/misc/AbtDerecho ... 86page.htm

May 4-5, 1989
http://www.spc.noaa.gov/misc/AbtDerecho ... 89page.htm

[djjordan]

Looking at some of the models with this squall line developing...... Wondering if SE Texas is going to see a widespread derecho event?

It could be possible. Frankly, I would not be surprised it happens. It rarely happens. I can think of some off my head; 1986, 1989.

May 17, 1986
http://www.spc.noaa.gov/misc/AbtDerecho ... 86page.htm

May 4-5, 1989
http://www.spc.noaa.gov/misc/AbtDerecho ... 89page.htm

I wonder .... in order for it to be classified as a Derecho .... does it have to move at a fairly good clip? It seems the faster it moves the stronger the winds in the bow echo segments. With this line it is going to be a slow mover.

[srainhoutx]

Storms increasing quickly between Laredo and Del Rio, W of San Antonio at this hour ahead of the dry line and activity along I-10 near Junction...

[Paul]

they are back building and slow enough to cause flooding issues IMO....still no word out of central Texas on the cell near Junction.

opps my bad here it is.....

TORNADO WARNING
TXC267-192215-
/O.NEW.KSJT.TO.W.0004.120319T2150Z-120319T2215Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SAN ANGELO TX
450 PM CDT MON MAR 19 2012

THE NATIONAL WEATHER SERVICE IN SAN ANGELO HAS ISSUED A

* TORNADO WARNING FOR...
CENTRAL KIMBLE COUNTY IN WEST CENTRAL TEXAS...

* UNTIL 515 PM CDT

* AT 448 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
TORNADO WAS 4 MILES NORTHWEST OF JUNCTION...OR NEAR JUNCTION...
MOVING EAST AT 40 MPH.

IN ADDITION TO DANGEROUS TORNADIC WINDS...OTHER HAZARDS INCLUDE...
LARGE DAMAGING HAIL UP TO GOLF BALL SIZE.
POTENTIALLY DEADLY LIGHTNING.

* THE TORNADO IS EXPECTED TO BE NEAR...
LONDON BY 515 PM CDT...

THIS INCLUDES INTERSTATE 10 BETWEEN MILE MARKERS 443 AND 461.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1000 PM CDT MONDAY EVENING
FOR WEST CENTRAL TEXAS.

[srainhoutx]

EWX extends Tornado Watch further W...

Code: Select all

WATCH COUNTY NOTIFICATION FOR WATCH 85...UPDATED
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
457 PM CDT MON MAR 19 2012

TXC019-031-053-137-171-259-265-271-299-325-385-463-465-200300-
/O.CON.KEWX.TO.A.0085.000000T0000Z-120320T0300Z/

TORNADO WATCH 85 REMAINS VALID UNTIL 10 PM CDT THIS EVENING FOR
THE FOLLOWING AREAS

IN TEXAS THIS WATCH INCLUDES 13 COUNTIES

IN SOUTH CENTRAL TEXAS

BANDERA               BLANCO                BURNET
EDWARDS               GILLESPIE             KENDALL
KERR                  KINNEY                LLANO
MEDINA                REAL                  UVALDE
VAL VERDE

THIS INCLUDES THE CITIES OF...BANDERA...BLANCO...BOERNE...
BRACKETTVILLE...BURNET...DEL RIO...FREDERICKSBURG...HONDO...
KERRVILLE...LEAKEY...LLANO...ROCKSPRINGS AND UVALDE.

[unome]

Looking at some of the models with this squall line developing...... Wondering if SE Texas is going to see a widespread derecho event?

It could be possible. Frankly, I would not be surprised it happens. It rarely happens. I can think of some off my head; 1986, 1989.

May 17, 1986
http://www.spc.noaa.gov/misc/AbtDerecho ... 86page.htm

May 4-5, 1989
http://www.spc.noaa.gov/misc/AbtDerecho ... 89page.htm

I wonder .... in order for it to be classified as a Derecho .... does it have to move at a fairly good clip? It seems the faster it moves the stronger the winds in the bow echo segments. With this line it is going to be a slow mover.

http://www.spc.noaa.gov/misc/AbtDerecho ... evelopment

Definition of a derecho
A derecho (pronounced similar to "deh-REY-cho" in English, or pronounced phonetically as "") is a widespread, long-lived wind storm that is associated with a band of rapidly moving showers or thunderstorms. Although a derecho can produce destruction similar to that of tornadoes, the damage typically is directed in one direction along a relatively straight swath. As a result, the term "straight-line wind damage" sometimes is used to describe derecho damage. By definition, if the wind damage swath extends more than 240 miles (about 400 kilometers) and includes wind gusts of at least 58 mph (93 km/h) or greater along most of its length, then the event may be classified as a derecho.

[weatherguy425]

Really need to watch the newly developing cells just to the south and west of San Antonio...they're discrete and strengthening rapidly.

[djjordan]

Awesome. That was the definition I was looking for earlier but I got sidetracked. While this doesn't look to be a derecho situation, it's gonna be one for the books for sure severe weather wise. Gonna be keeping a keen eye on the radar later on tonight.

[Andrew]

Really need to watch the newly developing cells just to the south and west of San Antonio...they're discrete and strengthening rapidly.

[Paul]

our Junction storm is passed and has a rotating wall cloud. I havent hear of any damage yet.

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN ANGELO TX
546 PM CDT MON MAR 19 2012

TXC319-192315-
/O.CON.KSJT.TO.W.0006.000000T0000Z-120319T2315Z/
MASON TX-
546 PM CDT MON MAR 19 2012

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM CDT FOR NORTHERN
MASON COUNTY...

AT 544 PM CDT... TRAINED WEATHER SPOTTERS REPORTED A ROTATING WALL
CLOUD. THIS WALL CLOUD WAS LOCATED NEAR MASON...MOVING NORTHEAST AT
45 MPH.

STORM HAZARDS INCLUDE...
DANGEROUS TORNADIC WINDS.
LARGE DAMAGING HAIL UP TO GOLF BALL SIZE HAIL.
DAMAGING WINDS IN EXCESS OF 60 MPH.

WITH POSSIBLE STORM IMPACTS...
OVERTURNED VEHICLES...
DAMAGE TO TREES...SOME MAY BE UPROOTED...
DAMAGE TO HOMES...MAY DESTROY MANUFACTURED HOMES...
DENTED VEHICLES...
MODERATE ROOF DAMAGE...
MAY BREAK WINDOWS ON VEHICLES AND HOMES...
MAY INJURE PEOPLE...PETS...AND LIVESTOCK LEFT UNPROTECTED...
DAMAGE TO TREE LIMBS...
LIGHT OBJECTS BLOWN AROUND...

THE TORNADO WILL BE NEAR...
FREDONIA BY 555 PM CDT...
PONTOTOC BY 605 PM CDT...

[srainhoutx]

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
607 PM CDT MON MAR 19 2012

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* TORNADO WARNING FOR...
NORTHERN FRIO COUNTY...
SOUTHEASTERN MEDINA COUNTY...

* UNTIL 645 PM CDT.

* AT 605 PM CDT...NWS METEOROLOGISTS HAVE DETECTED A SEVERE
THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR FRIO TOWN...OR
ABOUT 15 MILES WEST OF PEARSALL...MOVING NORTHEAST AT 50 MPH.

* SOME LOCATIONS IN THE WARNING INCLUDE YANCEY...MOORE...SCHATTEL...
BIRY...BIG FOOT...DEVINE...PEARSON...NOONAN...NATALIA AND
CASTROVILLE.

[srainhoutx]

Keeping a close eye SW of San Antonio. Multiple storms and a possible meso low forming at this time...

[Andrew]

San Antonio Storms:

[srainhoutx]

Code: Select all

BULLETIN - IMMEDIATE BROADCAST REQUESTED
   TORNADO WATCH OUTLINE UPDATE FOR WT 87
   NWS STORM PREDICTION CENTER NORMAN OK
   625 PM CDT MON MAR 19 2012
   
   TORNADO WATCH 87 IS IN EFFECT UNTIL 100 AM CDT FOR THE
    FOLLOWING LOCATIONS
   
   TXC013-021-029-055-091-127-149-177-187-209-255-283-287-311-453-
   479-491-493-200600-
   /O.NEW.KWNS.TO.A.0087.120319T2325Z-120320T0600Z/
   
   TX 
   .    TEXAS COUNTIES INCLUDED ARE
   
   ATASCOSA             BASTROP             BEXAR               
   CALDWELL             COMAL               DIMMIT              
   FAYETTE              GONZALES            GUADALUPE           
   HAYS                 KARNES              LA SALLE            
   LEE                  MCMULLEN            TRAVIS              
   WEBB                 WILLIAMSON          WILSON              
   
   
   ATTN...WFO...EWX...CRP...

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 87
NWS STORM PREDICTION CENTER NORMAN OK
625 PM CDT MON MAR 19 2012

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

SOUTH CENTRAL TEXAS

EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 625 PM UNTIL
100 AM CDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 25 MILES WEST SOUTHWEST OF
LAREDO TEXAS TO 25 MILES NORTHEAST OF AUSTIN TEXAS. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU7).

[unome]

definitely popping up now

http://nmq.ou.edu/



http://cimss.ssec.wisc.edu/snaap/convinit/quicklooks/

[texoz]

interesting convergence of cells moving toward Kerrville. There is one cell moving very fast south to north while others are moving SW to NE.

http://radar.weather.gov/radar.php?prod ... X&loop=yes

[srainhoutx]

Update from Jeff:

Severe weather outbreak underway over SW through NC TX



Tornado watches in effect for much of central TX.



Flash Flood Watch issued for all of SE TX effective from 300am to 600pm Tuesday.



Large supercells capable of producing very large hail (golfball size hail was reported in Utopia, TX), damaging winds, and tornadoes have rapidly developed this afternoon SW of San Antonio, TX. Upstream impulse in the base of the upper level trough over northern MX is advancing toward SW TX with increasing large scale lift over a strongly unstable and sheared air mass. Air mass has favorable low level shear in place with 40-50kts of shear in the lowest 3km along with good instability with 2500-3500 CAPE over SC/C TX. Supercells will be maintained through the evening hours with all severe modes possible. New Tornado Watch has been issued to include all of SC and C TX and goes up to our western counties until 100am this includes both the Austin and San Antonio metro areas.



Supercells should grow upscale into large squall line/MCS late tonight and move ESE toward the TX coast…wind damage threat will be increasing with time.

[tireman4]

From NWS San Antonio/Austin Facebook page...

Strong cell moving into Bandera County near Lost Maples State Park. Have had a report of Dime size hail.

[Andrew]

For anyone interested in watching the storms around San Antonio here are some chasers:

http://chase.tornadovideos.net/pages/full_screen

Watch vortex chasers right now