Severe Thunderstorm Warning 247, NWS San Angelo, TX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN ANGELO TX
501 PM CDT MON JUL 4 2005

.UPDATE...FIRST OF ALL HEAT ADVISORY IS VERIFYING NICELY OVER THE
CONCHO VALLEY AND THE HEARTLAND WITH SJT SO FAR TYING ANOTHER
RECORD THIS AFTERNOON AND MAY BREAK IT WITH STILL ABOUT 45
MINUTES TIL MAX HEATING POTENTIAL. ABILENE HAS BEEN
STRUGGLING...HOWEVER LATEST HEAT INDEX IS 104. AREAS OF THE
NORTHERN BIG COUNTRY WILL NOT ACHEIVE CRITERIA DUE TO THE OUFLOW
BOUNDARY THAT PASSED THROUGH THE AREA EARLIER IN THE DAY AND THE
RECENT AC DEVELOPMENT...THE WESTERN CONCHO VALLEY...AND CROCKETT
COUNTY WILL NOT ACHEIVE CRITERIA EITHER DUE TO SLIGHTLY LOWER HI
VALUES...AND THUS WILL TRIM THE ADVISORY BACK SOME.
AGAIN ABILENE IS CLOSE AND WILL LEAVE IN AT THIS TIME WITH IT
BEING VERY CLOSE.

AS FAR AS CONVECTION POTENTIAL THIS EVENING...ONE OF THE MOST
IMPRESSIVE HEAT LOW SIGNITURES I HAVE PERSONALLY SEEN ON CLEAR AIR
RETURNS FROM THE MAF RADAR. SO CONVERGENCE NORTHEAST OF THIS
FEATURE IS NO DOUBT SIGNIFICANT. VISIBLE IMAGERY OVER THE PAST
COUPLE OF HOURS IS SHOWING CU GETTING A LITTLE BETTER ORGANIZED
OVER THE SOUTHERN BIG COUNTRY AND WESTERN CONCHO VALLEY. WITH THAT
SAID...THE CU OVER THE CONCHO VALLEY DOES APPEAR TO BE HITTING THE
CAP AND HAVING TROUBLE. THE CU OVER THE SOUTHERN BIG COUNTRY IS
WHERE WE WILL FOCUS OUR ATTENTION OVER THE NEXT THREE HOURS TILL
01Z RIGHT ALONG THE OLD OUT FLOW BOUNDARY. ANY STORMS HEAR WILL
INITIALLY HAVE TROUBLE AS WELL...BUT WITH THE COMBINATION OF
TEMEPERATURES IN THE 100 TO 105 RANGE AND DEW POINTS IN THE MID
60S TO NEAR 70 SHOULD BE ABLE TO POP THROUGH THE CAP. STORMS HERE
WILL LIKELY HAVE DAMAGING WINDS WITH INVERTED V SOUNDINGS. HAIL
SOMEWHAT SMALLER THREAT DUE TO WARM MID LEVEL TEMEPRATURES.

&&

.PREV DISCUSSION... (ISSUED 320 PM CDT MON JUL 4 2005)

SHORT TERM...
NO RAINFALL...BUT A THUNDERSTORM OUTFLOW BOUNDARY PUSHED THROUGH
THE BIG COUNTRY...AND MOVED SOUTH OF THE CONCHO VALLEY THIS
MORNING. WINDS TEMPORARILY SHIFTED WINDS TO THE NORTHEAST AND
EAST...BUT HAVE SINCE SHIFTED BACK TO THE SOUTHEAST. TEMPERATURES
WERE A COUPLE DEGREES LESS WARM...ESPECIALLY ACROSS THE BIG
COUNTRY. CU AND AC HAVE DEVELOPED ACROSS THE BIG COUNTRY...WHERE
THERE WAS MORE LOW/MID LEVEL MOISTURE. A SURFACE LOW WAS OVER THE
EASTERN PERMIAN BASIN...WITH THE WATER VAPOR LOOP INDICATING A
SHORTWAVE MOVING INTO THE TEXAS PANHANDLE.

BEST CHANCE OF STORMS WILL BE OVER THE BIG COUNTRY THIS EVENING AS
UPPER LEVEL LOW MOVES EAST ACROSS REGION OF ENHANCED CU FIELS AND
MID LEVEL INSTABILITY. FURTHER SOUTH ACROSS CONCHO VALLEY AND
CROCKETT COUNTY...IT DOES NOT LOOK PROMISING ON VISIBLE
SATELLITE...BUT MAY SEE AN ISOLATED STORM OR TWO. THIS AREA IS IN
AN AREA OF LOW LEVEL CONVERGENCE...WITH NORTH/NORTHWEST WINDS IN
THE PERMIAN BASIN AND SOUTHEAST WINDS IN THE CONCHO VALLEY. MAY
SEE A SEVERE THUNDERSTORM OR TWO WITH CAPES OF 3000 J/KG. WILL
CONTINUE HEAT ADVISORY TONIGHT WITH MOST AREAS SEEING LOWS ONLY IN
THE MID 70S. BIG COUNTRY MAY NOT QUITE SEE CRITERIA OF HEAT
INDICES OF 105...BUT DEW POINTS REMAIN IN THE UPPER 60S...SO IT
WONT FEEL TOO MUCH BETTER. KDYX RADAR LIKELY DOWN UNTIL TUESDAY
WHEN THEY GET SOME EQUIPMENT TO REPAIR AC PROBLEM.

LONG TERM...

UPPER RIDGE WILL CONTINUE TO SUPRESS MOST RAINFALL THIS WEEK. NOT
AS STRAIGHT FORWORD A FORECAST HOWEVER...AS NORTHERN AND EASTERN
SECTIONS OF THE BIG COUNTRY MAY SEE AN ISOLATED THUNDERSTORM OR
TWO WITH WEAK UPPER RIDGE AND WEAK DISTURBANCES IN NORTHWEST FLOW
ALOFT.

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
TX...HEAT ADVISORY IN EFFECT FROM 7 PM SUNDAY UNTIL 7 AM CDT TUESDAY
      FOR THE FOLLOWING ZONES...BROWN...CALLAHAN...COKE...
      COLEMAN...CONCHO...KIMBLE...MASON...MCCULLOCH...MENARD...
      RUNNELS...SAN SABA...SCHLEICHER...SUTTON...TAYLOR...AND
      TOM GREEN.

&&

27/BRAZZELL

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE SAN ANGELO TX
230 PM CDT MON JUL 4 2005

TXZ049-054-064>066-071>073-076>078-098-099-113-114-127-128-139-140-
154-155-168>170-052030-
BROWN-CALLAHAN-COKE-COLEMAN-CONCHO-CROCKETT-FISHER-HASKELL-IRION-
JONES-KIMBLE-MASON-MCCULLOCH-MENARD-NOLAN-RUNNELS-SAN SABA-
SCHLEICHER-SHACKELFORD-STERLING-SUTTON-TAYLOR-THROCKMORTON-TOM GREEN-
230 PM CDT MON JUL 4 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WEST CENTRAL TEXAS.

.DAY ONE...TODAY

THE ATMOSPHERE WILL BECOME MODERATELY UNSTABLE OVER WEST CENTRAL
TEXAS LATE THIS AFTERNOON AND EVENING. WARM TEMPERATURES IN THE
MIDDLE LAYERS OF THE ATMOSPHERE WILL SUPPRESS MOST THUNDERSTORM
DEVELOPMENT. HOWEVER... A WEAK UPPER LEVEL DISTURBANCE MAY INTERACT
WITH INCREASING LOW LEVEL WINDS AND AN OLD OUTFLOW BOUNDARY TO FIRE
OFF SCATTERED SHOWERS AND THUNDERSTORMS OVER THE BIG COUNTRY TOWARD
MID EVENING. A FEW STORMS WILL LIKELY PERSIST INTO THE NIGHTTIME
HOURS AND DRIFT SLOWLY SOUTHEAST INTO THE HEARTLAND. ADDITIONAL
THUNDERSTORMS MAY FORM OVER THE EASTERN PERMIAN BASIN AND DRIFT INTO
THE WESTERN CONCHO VALLEY DURING THE EVENING. DAMAGING WINDS AND
LARGE HAIL WILL BE PRIMARY SEVERE WEATHER THREATS OVER WEST CENTRAL
TEXAS THIS EVENING.

BEYOND THE THUNDERSTORM THREAT...DRY GRASSES AND VERY LOW RELATIVE
HUMIDITIES WILL CREATE VERY HIGH WILDFIRE DANGER THROUGH LATE
EVENING. ANY SPARK FROM FIREWORKS OR OTHER OUTDOOR ACTIVITIES COULD
INITIATE A RAPIDLY SPREADING WILDFIRE. WEST CENTRAL TEXANS ARE
ADVISED TO EXERCISE EXTREME CAUTION WHEN CELEBRATING THE FOURTH OF
JULY HOLIDAY OUTDOORS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH MONDAY

A FEW THUNDERSTORMS WILL BE POSSIBLE TUESDAY...MAINLY OVER THE
EASTERN BIG COUNTRY AND THE HEARTLAND OF TEXAS. DRY...HOT WEATHER
WILL OTHERWISE PREVAIL OVER WEST CENTRAL TEXAS THROUGH THE REMAINDER
OF THE WEEK. ELEVATED WILDFIRE DANGER WILL CONTINUE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED LATE THIS AFTERNOON AND
EVENING...NORTH OF A MERTZON TO SAN SABA LINE.

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