Flash Flooding in Texas, March 27, 2001

SOUTH CENTRAL TEXAS FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
930 AM CST TUE MAR 27 2001

CURRENT SURFACE ANALYSIS...HIGH PRESSURE RIDGE CENTERED OVER
THE EASTERN SECTIONS OF MID-CENTRAL UNITED STATES IS SLIDING
SOUTHEAST. LOW PRESSURE TROUGHS EXTENDS FROM THE NORTHERN PLANS
SOUTHWARD INTO WESTERN TEXAS AND NEW MEXICO IS SLIDING SOUTHEAST.
NORTH TO NORTHEAST WINDS PREVAILING ACROSS THE COUNTY WARNING
AREA AT 8 TO 12 MPH WITH ISOLATED GUSTS. TEMPERATURES RANGING IN
THE 40S ACROSS THE HILL COUNTRY WITH UPPER 40S TO LOW 50S ACROSS
THE RIO GRANDE PLAINS REGION AND SOUTH CENTRAL TEXAS.

CONDITIONS ALOFT...A SHORT WAVE TROUGH IS MOVING SOUTHEAST FROM
WESTERN TEXAS ACROSS THE HILL COUNTRY AND INTO SOUTH CENTRAL TEXAS
AND EASTWARD. 88DOGS HAVE AREAWIDE LIGHT RAIN AND DRIZZLE WITH
SHOWERS AND THUNDERSTORMS OVER THE HILL COUNTRY MOVING EAST AND
DEVELOPING SOUTHWARD. THIS SHORTWAVE TROUGH IS JUST THE FIRST IN A
LONG LINE OF SEVERAL TO COME.

LOOK FOR THE CURRENT WEATHER CONDITIONS TO PREVAIL OVER THE NEXT TWO
OR POSSIBLY THREE DAYS. WILL HAVE PERIOD OF VARIABLE CLOUDINESS AND
LESSER RAIN...BUT OVERALL CONDITIONS WILL BE MOSTLY CLOUDY WITH POPS.
THE 430 AM ZONE FORECAST HAS TODAYS WEATHER HANDLED WELL. SEE NO
REASON TO UPDATE AT THIS CURRENT TIME.

PREVIOUS DISCUSSION...
WEAK S/W (DISTURBANCE) WILL TRAVERSE EASTWARD ACROSS SOUTH CENTRAL
TEXAS AREA TODAY ACROSS A SHALLOW MOIST COOL POOL.  DIGGING TROUGH
TO WEST WILL LIKELY RESULT IN AN INCREASE IN THE LOW LEVEL MOIST
ADVECTION FROM THE GULF...THUS RAIN POPS IN LIKELY CATEGORY WITH A
FEW SHOWERS OR THUNDERSTORMS POSSIBLE OVER SOUTH CENTRAL PORTIONS.
LIGHT RAIN OR DRIZZLE WITH A FEW SHOWERS LIKELY HILLS AND WESTERN
PLATEAU AREAS.

TONIGHT...S/W WILL PASS BUT CONTINUED DIG OF JET TO WEST OF AREA
WILL INCREASE LOW LEVEL FLOW FROM GULF...LIGHT RAIN AGAIN LIKELY
THROUGHOUT.  ANOTHER WEAK S/W WILL PUSH ACROSS WEDNESDAY WITH
SHOWERS AND THUNDERSTORMS MORE LIKELY AS UPPER LEVELS DESTABILIZE.
ANOTHER BREAK AS S/W PASSES BY WEDNESDAY NIGHT AND ADVECTION
PROCESSES FROM GULF LESSENS.  NEGATIVELY TILTED JET SWEEPS A MAJOR
DISTURBANCE THROUGH AREA THURSDAY WITH RAIN CHANCES GOOD WITH
SHOWERS AND THUNDERSTORMS. DEPENDING UPON STABILITY OF LOWER
LEVELS...A FEW OF THESE STORMS COULD BECOME SEVERE.

MORE SHOWERS POSSIBLE THURSDAY NIGHT AND INTO FRIDAY AS WEAKER S/W'S
TRAVERSE AREA.  TROUGH FINALLY MOVES THROUGH AREA FRIDAY BUT FLOW
THEN BECOMES ZONAL AND LOW LEVEL MOISTURE ZOOMS BACK IN FROM
GULF...WITH ANOTHER CLOUDY...DRIZZLY DAY.  INCREASING CHANCES FOR
RAIN SATURDAY INTO SUNDAY (DESPITE YESTERDAYS PROMISED 80S) AS
MODELS NOW SHOW MAJOR UPPER TROUGH MOVING THROUGH.  NEXT REAL DRY
WEATHER DAY APPEARS MONDAY...BUT STAY TUNED...MODELS IN LATER
PERIODS NOT PROVING VERY RELIABLE IN ACTIVE WESTERLIES.

.PRELIMINARY NUMBERS...
AUS 55/51/59/50 7773
DRT 60/55/62/52 4733
SAT 58/53/62/52 7863

.EWX...NONE.