Severe Thunderstorm Warning 92, NWS Austin/San Antonio, TX

SOUTH CENTRAL TEXAS FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
937 PM CDT THU JUN 5 2003

LINE OF SCATTERED CONVECTION HAS FORMED NEAR BOUNDARY ALONG NORTHERN
EDGE OF THE CWA. LINE IS DRIFTING SLOWLY NORTH. MEANWHILE, MCSS
GALORE OVER MEXICO, EASTERN NEW MEXICO, AND WEST TEXAS PROGRESSING
TOWARD CWA. THUNDERSTORMS JUST WEST OF VAL VERDE COUNTY SHOULD
MAINTAIN THE NEXT FEW HOURS DUE TO SHORT-WAVE, 15 KNOT LOW LEVEL JET,
AND ABOVE MENTIONED BOUNDARY. STRONG THUNDERSTORM THAT FORMED EARLIER
OVER WESTERN GILLESPIE COUNTY AND 43KT GUST AT DRYDEN SUGGESTS
SEVERE STORMS STILL POSSIBLE. MCSS MOVING EAST ACROSS SOUTHEASTERN
NEW MEXICO/FAR WESTERN TEXAS AND DROPPING SOUTH ACROSS THE TEXAS
SOUTH PLAINS SHOULD MERGE OVER THE PERMIAN BASIN, THEN TRACK TO THE
SOUTHEAST INTO THE CWA LATER TONIGHT ON THE THETA-E AND LOW LEVEL JET
AXES. EWX CWA FORECASTS GENERALLY ON TRACK. WILL UPDATE, HOWEVER TO
INCLUDE MENTION OF LOCALLY HEAVY RAINS. MAY DROP LOW TEMPERATURES A
FEW AREAS TO TAKE INTO ACCOUNT COOLER TEMPERATURES ALOFT SURFACING ON
DOWNBURST WINDS. 04/08/JB.

PRELIMS...UPDATED TONIGHT
AUS 068/085/067/089/071 67223
DRT 068/089/070/093/074 65222
SAT 070/087/068/090/073 47222

PREVIOUS DISCUSSION...
AFTER A LARGE THUNDERSTORM COMPLEX MOVED THROUGH THE AREA THIS
MORNING AND MESSED UP MODEL INITIALIZATIONS, AN EVEN MORE MASSIVE
SYSTEM WILL DEVELOP OVER THE HIGH PLAINS LATE TONIGHT. THIS SYSTEM
IS GOING TO BE HELD UP SOME BY SYNOPTIC LEVEL WIND FLOW WHICH WILL
TEMPORARILY KEEP MID-LEVEL WINDS WESTERLY ALSO THE ATMOSPHERE WILL
NEED MORE TIME TO DESTABILIZE AT LOW LEVELS IN ORDER FOR THE MCS TO
EVOLVE. THUS AM OPTING FOR CONSERVATIVE RAINFALL CHANCES BY NW FLOW
STANDARDS FOR TONIGHT AGAIN. WILL CHOOSE A 20-50 PERCENT RANGE FROM
NORTH TO SOUTH WITH MAINLY AFTER MIDNIGHT WORDING FOR TONIGHT THE
EXCEPTION WILL BE FOR AREAS ALONG THE RIO GRANDE WHICH MAY SEE
ISOLATED SEVERE STORMS ROLL OFF THE HIGHER ELEVATIONS OF MEXICO. A
SMALLER MCS IS POSSIBLE OVER THE RIO GRANDE PLAINS THIS EVENING, BUT
IT SHOULD NOT INTERFERE WITH THE STRONGER SYSTEM UPSTREAM. BY
MORNING, EXPECT THE SYSTEM TO BE EITHER MOVING THROUGH OUR NORTHERN
COUNTIES OR JUST TO THE NORTH WITH RAPID DESTABILIZATION ALONG AND
AHEAD OF THE STORM SYSTEM. WILL THEREFORE OFFER LIKELY POPS
AREA-WIDE FOR FRIDAY WITH LOCALLY HEAVY RAIN AND SEVERE WEATHER
MENTIONED. AGREE WITH THE GENERAL 12Z AVN PATTERN OVER THE AREA BY
24 HOURS AFTER THE INITIALIZATION PROBLEMS BEGIN TO DISAPPEAR.

TIMING FOR THE ISSUANCE OF A FLASH FLOOD WATCH IS NOT GOOD THIS
AFTERNOON WITH MOST OF THE RAIN TO FALL WELL AFTER MIDNIGHT.
HOWEVER, A WATCH MAY NEED TO BE CONSIDERED BY LATE EVENING IF
THUNDERSTORM TIMING IS ACCELERATED OVER WEST CENTRAL TX.

FRIDAY NIGHT LOOKS DRY FOR NOW AS THE STRONG DISTURBANCE BRINGS A
COOL FRONT THROUGH ALL OF THE AREA. FOR SUNDAY, THE AVN/GFS HAS BEEN
FAIRLY CONSISTENT IN DRAGGING ANOTHER STRONG SHORTWAVE THROUGH THE
AREA WITH ANOTHER NORTHERLY WIND SHIFT BEHIND IT OVER A SIMILAR
TIME-FRAME AS THE PREVIOUS SYSTEM. BETWEEN THESE TWO SYSTEMS, WILL
KEEP A CAUTIOUS SLIGHT CHANCE POP IN FOR SATURDAY TO ACCOUNT FOR THE
NW FLOW PATTERN THAT HAS LITTLE FOCUSING INDICATED IN THE MODEL
DATA. AFTER THE SUNDAY DISTURBANCE PASSES, RIDGING IN THE UPPER
LEVELS BEGINS WITH NIL POPS LOOKING REASONABLE KICK OFF A MOSTLY DRY
WORK WEEK. WILL MAINTAIN NIL POPS AND ABOVE CLIMATOLOGY ON TEMPS
MONDAY AND BEYOND.

.EWX...NONE

TXZ171>173-183>194-202>209-217>225-228-061100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
547 AM CDT THU JUN 5 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL TEXAS.

.DAY ONE...TODAY
A LINE OF STRONG THUNDERSTORMS WILL BE MOVING ACROSS THE NORTHERN-
MOST COUNTIES OF BOTH THE HILL COUNTRY AND SOUTH CENTRAL TEXAS
STARTING AROUND DAWN IN LLANO COUNTRY AND MOVING ACROSS
WILLIAMSON COUNTY BY MID MORNING IF THE STORM SYSTEM MAINTAINS ITS
CURRENT SPEED.  THERE IS A CHANCE THE THUNDERSTORMS COULD BRUSH THE
AUSTIN METROPOLITAN AREA.  DAMAGING WINDS AND HEAVY RAINS OF 1 TO 2
INCHES ARE THE MAIN THREATS.  ONCE THESE STORMS MOVE THROUGH AND THE
ATMOSPHERE HAS TIME TO RECOVER...STRONG STORMS MAY REDEVELOP THIS
AFTERNOON...MAINLY ALONG AND NORTH OF U.S. HIGHWAY 90.  AGAIN...
DAMAGING WINDS AND HEAVY RAINS POSSIBLY LEADING TO FLASH FLOODING
WILL BE THE MAIN THREATS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED THIS MORNING AND AGAIN THIS
AFTERNOON.

.DAYS TWO THROUGH SEVEN...
A SLOW-MOVING FRONT WILL SERVE AS A FOCAL POINT FOR HEAVY RAINS
TONIGHT AND FRIDAY.  FLASH FLOODING AND POSSIBLY SOME RIVER FLOODING
MAY RESULT FROM RAINS OF UP TO 2 TO 3 INCHES IN SPOTS MAINLY
OVER THE HILL COUNTRY AND NORTHERN SECTIONS OF SOUTH CENTRAL TEXAS.