Flash Flood Warning 93, NWS Midland/Odessa, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIDLAND TX
352 PM CDT SUN AUG 1 1999

SHORT TERM...
A QUASI-STATIONARY BOUNDARY EXTENDS SOUTHWEST FROM A LOW PRESSURE
CENTER BETWEEN KCDS AND KAMA INTO EXTREME NORTHERN LEA COUNTY...
WHERE IT CURLS BACK TO THE NORTHWEST ALONG THE MOUNTAINS OF EAST
CENTRAL NEW MEXICO.  ALOFT...AN UPPER LOW...POSSIBLE ORIGINATING FROM
THE TUTT...CONTINUES TO WOBBLE (BUT NOT FALL DOWN) OVER THE PERMIAN
BASIN.  DESPITE A MARKED COOLING AND STABILIZATION OF THE LOWER
COLUMN OVER THE PAST 24 HOURS...THERES ENOUGH INSTABILITY OUTSIDE TO
SUPPORT SCATTERED CONVECTION.  INDEED...A LOOK OUT THE WINDOW REVEALS
TOWERS GOING UP ALQDS.  PRECIPITABLE WATER VALUES ARE EXPECTED TO
REMAIN IN THE 3 TO 4 CM RANGE OVERNIGHT...AND GIVEN THE EXPECTED WEAK
FLOW ALOFT...SCATTERED SLOW MOVING THUNDERSTORMS PRODUCING LOCALLY
HEAVY RAINFALL ARE POSSIBLE THROUGH THE LATE EVENING HOURS.  THE
MIX OF BUOYANCY AND SHEAR ISNT ALL THAT IMPRESSIVE...THUS WE EXPECT
CONVECTION TO REMAIN MULTICELLULAR IN NATURE.  WHILE WE CANNOT RULE
OUT THE POSSIBILITY OF ONE OR TWO WET MICROBURSTS PRODUCING WINDS
CLOSE TO SEVERE CRITERION...THE LIKELIHOOD OF THIS OCCURRING IS
SUFFICIENTLY LOW TO PRECLUDE MENTION IN THE ZONE FORECASTS.  IN
ADDITION...CONFIDENCE IS NOT HIGH IN A WIDESPREAD HEAVY RAINFALL
EVENT...CONSEQUENTLY WE WILL HOLD OFF ON PULLING THE TRIGGER FOR A
FLASH FLOOD WATCH.

LONG TERM...
NOT MUCH CHANGE IS EVIDENT THROUGH THE SHORT TERM AS THE CWFA REMAINS
UNDER A WEAK FLOW REGIME...WITH THE MODELS MAINTAINING THE UPPER
WEAKNESS ALOFT THROUGH THE PERIOD.  THERES SOME UNCERTAINTY
REGARDING THE TRANSLATION OF THE BOUNDARY TO THE NORTH OF THE CWFA.
THERE DOES NOT APPEAR TO BE MUCH IN THE WAY OF SYNOPTIC SIGNAL TO
JUSTIFY A SOUTHWARD TRANSLATION INTO THE PERMIAN BASIN.  INDEED...
DAYTIME HEATING OF THE AIRMASS NORTH OF THE BOUNDARY SHOULD ACT
FRONTOLYTICALLY...WHILE THE FAST UPPER FLOW OVER THE NORTHERN PLAINS
SHOULD INDUCE A SURFACE LEE TROUGH...FURTHER WEAKENING THIS BOUNDARY.
THUS ANY SUBSTANTIAL SOUTHWARD TRANSLATION OF THIS BOUNDARY WILL
COME FROM AUGMENTATION FROM COLD POOLS GENERATED FROM STORMS TO THE
NORTH OF THE CWFA.  WERE EXPECTING THIS BOUNDARY TO MAYBE PUSH INTO
THE NORTHERN CWFA TOMORROW MORNING BEFORE BECOMING DIFFUSE AND
LIFTING NORTHWARD MONDAY AFTERNOON.

NEVERTHELESS...THIS BOUNDARY WILL SERVE AS A FOCUSING MECHANISM FOR
ANOTHER ROUND OF SCATTERED CONVECTION OVER THE NORTHERN BASIN MONDAY
AFTERNOON AND EVENING.  ADDITIONAL WIDELY SCATTERED THUNDERSTORMS
SHOULD DEVELOP BY EARLY AFTERNOON OVER THE OROGRAPHICALLY-FAVORED
AREAS OF WEST TEXAS AND SOUTHEASTERN NEW MEXICO.  ON TUESDAY...UPPER
SUPPORT SHOULD WANE SLIGHTLY...AND ALONG WITH IT THE CHANCES FOR
RAIN.  TEMPERATURES THROUGH THE PERIOD WILL BE MODULATED SOMEWHAT BY
CLOUDS AND EVAPORTRANSPIRATION...AND GUIDANCE SEEMS TO HAVE A HANDLE
ON THIS...THUS WELL HANG FAIRLY CLOSE TO WHAT THE MACHINE HAS.

REAL LONG TERM...
THE AMPLIFICATION OF THE LONG WAVE FEATURES OVER NORTH AMERICA
CONTINUE TO BE INDICATED BY THE MEDIUM RANGE MODELS.  WITH UPPER
HEIGHTS BUILDING OVER THE WEST AND A LONG WAVE TROUGH DEVELOPING
OVER THE EAST...WEAK NORTHWESTERLY FLOW SHOULD CONTINUE OVER THE
AREA THROUGH THE END OF THE WORK WEEK.  WITH LITTLE NET CHANGE IN
THIS AIRMASS...OROGRAPHICALLY DRIVEN DIURNAL CONVECTION APPEARS TO
BE A SAFE BET.  OUT ON THE PLAINS...WE MAY BE FAR ENOUGH SOUTHWEST TO
GET ANY MCS ACTIVITY THAT ROLLS OFF THE CENTRAL HIGH PLAINS...BUT
OUTFLOW BOUNDARIES MAY PROVIDE FOCI FOR WIDELY SCATTERED DIURNAL
ACTIVITY.  REGARDING TEMPERATURES...WE SHOULD BE AT OR SLIGHTLY BELOW
NORMAL THROUGH FRIDAY.

THATS A WRAP...PITCH COUNTS FOLLOW...70.

THE PRELIMINARY GUIDANCE BELOW IS FOR COORDINATION PURPOSES ONLY.
OFFICIAL FORECASTS ARE CONTAINED WITHIN THE WEST TEXAS/SOUTHEASTERN
NEW MEXICO ZONE FORECAST.

MAF  69/90/69/90    3332
LSA  65/89/66/90    3432
E41  67/90/68/91    3332
6R6  68/91/69/92    3222
MRF  61/84/61/85    3222
CNM  68/89/67/92    3332

.MAF...
TX...NONE.
NM...NONE.