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000
FXUS64 KSJT 230930
AFDSJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
430 AM CDT THU MAY 23 2013

.SHORT TERM...
SHORT TERM FORECAST CONCERNS ARE WITH SEVERE WEATHER POTENTIAL
ACROSS OUR NORTHERN COUNTIES THIS EVENING/EARLY TONIGHT...AND WITH
POPS THIS EVENING/TONIGHT ACROSS ROUGHLY THE NORTHWEST HALF OF
WEST CENTRAL TEXAS.

LOW-LEVEL MOISTURE RETURN IS CURRENTLY UNDERWAY ACROSS OUR AREA WITH
SOUTHEAST WINDS AND DEWPOINTS CLIMBING INTO THE 60S. PATCHY LOW
CLOUDS HAVE DEVELOPED INTO OUR SOUTHERN COUNTIES...AND EXPECT THE
LOW CLOUD COVERAGE EXPAND ACROSS THE SOUTHEASTERN THIRD TO HALF OF
WEST CENTRAL TEXAS BY 12Z. THE COLUMN WILL CONTINUE TO MOISTEN TODAY
WITH PRECIPITABLE WATER VALUES INCREASING TO BETWEEN 1.1 AND 1.3
INCHES BY EARLY THIS EVENING. CLEARING OF THE LOW CLOUDS WILL OCCUR
BY MID-LATE MORNING...WITH HOT AND RELATIVELY HUMID CONDITIONS THIS
AFTERNOON. GOING WITH HIGHS IN THE LOWER TO MID 90S WITH THE WARMER
READINGS ACROSS THE CONCHO VALLEY AND WESTERN BIG COUNTRY.

ALTHOUGH AN UPPER RIDGE WILL BUILD NORTH ACROSS THE PLAINS STATES
TODAY...FORECAST MODELS HAVE BEEN CONSISTENTLY SHOWING CONVECTIVE
DEVELOPMENT BY LATE AFTERNOON OVER NORTHWEST TEXAS...IN THE VICINITY
OF WHERE THE SOUTHWARD-MOVING COLD FRONTAL BOUNDARY INTERSECTS THE
DRYLINE. OUR NORTHERN BORDER COUNTIES SHOULD BE JUST SOUTH OF THE
COLD FRONT BY THIS EVENING. THE FRONT IS EXPECTED TO STALL DURING
THE EVENING. STORMS WHICH INITIALLY DEVELOP DURING THE EARLY EVENING
WILL HAVE A POTENTIAL MAINLY FOR VERY LARGE HAIL AND DAMAGING
WINDS...GIVEN STRONG INSTABILITY AND SUFFICIENT VERTICAL WIND SHEAR.
MODELS INDICATE THAT STORMS COULD DEVELOP INTO A MESOSCALE
CONVECTIVE SYSTEM /MCS/...BUT HAVE UNCERTAINTY IN THE SUBSEQUENT
TRACK. ONE POSSIBILITY IS FOR THE MCS TO TRACK EAST-SOUTHEAST ALONG
OR JUST SOUTH OF THE STALLING FRONTAL BOUNDARY. ANOTHER POSSIBILITY
IS FOR THE CONVECTIVE CLUSTER TO DEVELOP MORE TO THE SOUTH TOWARD
THE BETTER LOW-LEVEL INFLOW. WHILE TAKING A SOMEWHAT CONSERVATIVE
APPROACH TO POPS AT THIS TIME...HAVE THE HIGHEST POP ACROSS THE
WESTERN BIG COUNTRY TONIGHT...WITH SLIGHT CHANCE POPS EXTENDING AS
FAR SOUTHEAST AS A COLEMAN TO SONORA LINE. EXPECT ADJUSTMENTS TO BE
MADE TO THE POPS LATER TODAY WITH NEW MODEL DATA AND AS CONVECTIVE
TRENDS BECOME BETTER DISCERNED. IF A MCS DEVELOPS WITH A DECENT COLD
POOL...COULD HAVE STRONG WINDS ALONG THE LEADING EDGE/GUST FRONT
DURING THE EVENING.

WITH THE INCREASINGLY MOIST AIRMASS AND THE POSSIBILITY OF A
SLOWLY PROPAGATING MCS OR CONVECTIVE CLUSTER...LOCALLY HEAVY
RAINFALL IS POSSIBLE THIS EVENING AND TONIGHT. WHILE THE MODELS MAY
BE HAVING SOME CONVECTIVE FEEDBACK ISSUES WITH THE BULLSEYE QPF
PATTERNS JUST NORTHWEST OF OUR FORECAST/WARNING AREA...THE
CONSISTENCY AMONG THE MODELS /IN CURRENT AND PREVIOUS MODEL RUNS
OF THE NAM AND GFS/ IN SHOWING THIS PATTERN IS WORTH NOTING.

.FRIDAY AND SATURDAY...
A GREAT DEAL OF UNCERTAINTY FOR FRIDAY INTO SATURDAY ACROSS WEST
CENTRAL TEXAS...JUST DUE TO THE FACT THAT SO MUCH OF THE FORECAST
RELIES ON WHAT HAPPENS THURSDAY NIGHT. RESIDUAL OUTFLOW BOUNDARIES
AND A POSSIBLE MESOSCALE INDUCED VORT MAY WELL BE ACROSS THE
AREA...WITH MODELS ALL SUGGESTING FRIDAY AND FRIDAY NIGHT WILL SEE
THE BEST RAIN CHANCES ACROSS THE AREA. LOOKS LIKE THE CENTRAL AND
WESTERN PORTIONS OF WEST CENTRAL TEXAS WILL BE THE MAIN AREAS TO
FOCUS ON...WITH THE NORTHWEST HILL COUNTRY AND THE HEARTLAND STILL
UNDER THE INFLUENCE OF THE WEAK UPPER LEVEL RIDGE. WILL CONTINUE
THE SLIGHT CHANCE TO CHANCE POPS AREA WIDE...AND SEE IF WE CAN GET
SOME MUCH NEEDED RAINFALL.

.SUNDAY THROUGH WEDNESDAY...
MAY SEE AN ISOLATED SHOWER OT STORM LINGER INTO SUNDAY...BUT AT
THIS POINT WILL KEEP THE FORECAST DRY...AS THE ANOTHER WEAK UPPER
LEVEL RIDGE TRIES TO BUILD IN ACROSS THE AREA. STRONG UPPER LEVEL
TROUGH WILL THEN DEVELOP AND MOVE INTO THE WESTERN US FOR NEXT
WEEK...WITH SOUTHWEST GLOW ALOFT FOR WEST CENTRAL TEXAS. THIS
SYSTEM MAY GET CLOSE ENOUGH TO THE AREA BY WEDNESDAY TO ADD RAIN
CHANCE TO THE AREA...BUT THESE SYSTEMS ARE OFTEN A LITTLE SLOWER
TO COME OUT OF THE SOUTHWEST US THAN THE MODELS INDICATE...SO WILL
LEAVE OUT FOR NOW. WILL KEEP TEMPERATURES AT OR A LITTLE ABOVE
NORMAL FOR THE PERIOD.

&&

.PRELIMINARY POINT TEMPS/POPS...
ABILENE  93  70  89  68  86 /   5  30  30  30  20
SAN ANGELO  96  70  89  68  88 /   5  30  30  30  20
JUNCTION  92  70  89  69  86 /   0  10  20  20  10

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

19/07/07