DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 101300
SWODY1
SPC AC 101258

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0758 AM CDT THU MAY 10 2012

VALID 101300Z - 111200Z

...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF SRN THROUGH SERN TX...

...SYNOPSIS...
A PROGRESSIVE SPLIT FLOW PATTERN WILL PREVAIL THIS PERIOD...WITH NRN
MEXICO UPR LOW CONTINUING E TO ENE INTO CNTRL TX AS LWR GRT LKS
TROUGH FURTHER AMPLIFIES UPON MOVING E INTO NEW ENGLAND AND THE MID
ATLANTIC. ELSEWHERE...POSITIVE-TILT PACIFIC NW/NRN RCKYS TROUGH
EXPECTED TO REACH THE NRN PLNS BY 12Z FRI.

AT THE SFC...FRONTAL ZONE THAT ENTERED THE LWR RIO GRANDE ON TUE
SHOULD STRENGTHEN AND REDEVELOP NWD INTO S TX LATER TODAY...WHILE
THE ERN PART OF THE SAME BOUNDARY CONTINUES SLOWLY SE ACROSS
CNTRL/SRN FL. THE BOUNDARY...AND ASSOCIATED WAA FIELD...WILL SERVE
AS A FOCUS FOR STRONG TO SVR TSTMS OVER PARTS OF TX TODAY THROUGH
EARLY FRI...AND ALSO MAY SUPPORT SCTD STRONG STORMS IN FL THIS AFTN.


...S CNTRL INTO S AND SE TX TODAY/TNGT...
COMBINATION OF VERY RICH MOISTURE /PW 1.25 TO 1.75 INCHES WITH UPR
60S TO LOW 70S F DEWPOINTS/...INCREASING WAA/UPR ASCENT WITH
APPROACHING UPR LOW...AND SFC HEATING EXPECTED TO SUPPORT SEVERAL
EPISODES OF STRONG TO SVR TSTMS OVER A LARGE PART OF SRN AND SERN TX
THIS PERIOD.

CURRENT BAND OF SCTD STORMS OVER THE LWR RIO GRANDE VLY LIKELY IS
BEING FOSTERED BY LOW LVL WAA/MOISTURE TRANSPORT ATOP AFOREMENTIONED
SFC FRONT. THE STORMS IN THE SRN PORTION OF THE BAND LIKELY WILL
BECOME MORE NEARLY SFC-BASED AS SFC HEATING DESTABILIZES REGION
LATER THIS MORNING. WITH AMPLE SHEAR ALREADY IN PLACE FOR
SUPERCELLS...SETUP MAY POSE A RISK FOR TORNADOES IN ADDITION TO
LARGE HAIL/LOCALLY DMGG WIND.

LATER TODAY ANOTHER ROUND OF SVR STORMS IS EXPECTED TO DEVELOP INVOF
THE FRONT AND IN EXIT REGION OF STRENGTHENED S/SSELY LLJ IN THE SRN
HILL COUNTRY AND/OR THE AREA NEAR DEL RIO. WITH DIURNAL
HEATING...STEEP MID LVL LAPSE RATES...AND CONTINUED LOW LVL MOISTURE
INFLOW...STRONG INSTABILITY WILL EXIST ACROSS REGION...WITH SBCAPE
ON THE ORDER OF 2000-2500 J/KG. COUPLED WITH 50+ KT WSWLY DEEP
SHEAR AND INCREASED FORCING FOR ASCENT E OF APPROACHING UPR
LOW...SETUP COULD YIELD A FAIRLY CONCENTRATED AREA OF STRONG TO SVR
SUSTAINED STORMS/SUPERCELLS. THESE COULD PRODUCE VERY LARGE
HAIL...DMGG WIND...AND TORNADOES. OTHER SVR STORMS MAY FORM ON THE
NRN MEXICAN MOUNTAINS AND MOVE E INTO S TX. ALL OF THIS ACTIVITY
COULD EVOLVE INTO A SIZABLE MCS...WITH EMBEDDED FORWARD-PROPAGATING
SEGMENTS EXTENDING A RISK FOR SVR WIND...HAIL...AND POSSIBLY ISOLD
TORNADOES TO THE TX CSTL PLN THIS EVE. PARTS OF S CNTRL TX TO THE
CNTRL TX GULF CST MAY REQUIRE UPGRADE TO MDT RISK AS THE MOST LIKELY
STORM MODE AND AREA OF AFTN STORM DEVELOPMENT BECOME MORE APPARENT.

ADDITIONAL STRONG TO SVR STORMS MAY AFFECT PARTS OF DEEP S TX AND
THE MIDDLE/UPR TX CSTL PLN THROUGH FRI AS LOW LVL MOISTURE CONTINUES
TO FLOW INTO REGION BENEATH FAVORABLE UPR DIFLUENCE.

...SERN FL THIS AFTN...
AFOREMENTIONED COLD FRONT AND SEA BREEZE BOUNDARIES MAY SUPPORT
ISOLD TO WIDELY SCTD TSTMS THIS AFTN...PRIOR TO ONSET OF MORE
STRONGLY SUBSIDENT MID-LVL THIS EVE. RELATIVELY STEEP LOW LVL LAPSE
RATES AND RICH MOISTURE /PW AOA 1.50 INCHES AND SFC DEWPOINTS NEAR
70 F/ MAY FOSTER LOCALLY STRONG/POSSIBLY SVR DOWNDRAFTS AND PERHAPS
HAIL GIVEN 25-30 KT WLY MID LVL FLOW.

...NRN PLNS LATE THIS AFTN/EVE...
LOW-LVL MOISTURE RETURN WILL BE QUITE LIMITED AHEAD OF COLD FRONT
THAT WILL CROSS THE DAKOTAS LATER TODAY/TNGT ATTENDANT TO NRN RCKYS
UPR TROUGH. SFC HEATING WILL NEVERTHELESS DESTABILIZE REGION NEAR
THE FRONT...AND LIKELY WILL CONTRIBUTE TO STORM DEVELOPMENT ALONG
OR...MORE LIKELY...IMMEDIATELY BEHIND THE FRONT LATE TODAY INTO
TNGT. A CONDITIONAL RISK FOR STRONG WIND GUSTS CANNOT BE RULED OUT
IF SFC-BASED STORMS DO INDEED DEVELOP...GIVEN STEEP PRE FRONTAL LOW
LVL LAPSE RATES AND MODERATE MEAN WIND FIELD.
ATTM...HOWEVER...CONFIDENCE IN SUCH A SCENARIO REMAINS TOO LOW TO
WARRANT INCLUSION OF SVR WIND PROBABILITIES.

..CORFIDI/GARNER.. 05/10/2012

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