Severe Thunderstorm Warning 64, NWS Midland/Odessa, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX
147 PM CST FRI MAR 31 2000

IN THE SHORT TERM...AN UPDATE IS FORTHCOMING TO ADJUST
FORECASTED HIGH TEMPERATURES DOWNWARD OVER THE NORTHERN
PORTIONS OF THE FORECAST AREA DUE TO THE PERSISTENT OVERCAST
CONDITIONS.

VISIBLE SATELLITE IMAGERY SHOWS CLOUDY CONDITIONS GENERALLY NORTHEAST
OF A DRYDEN TO ABQ LINE.  RADAR INDICATES SOME LIGHT RAIN FALLING
OVER PORTIONS OF GAINES AND ANDREWS COUNTIES...PROBABLY THE RESULT
OF SOME ISENTROPIC LIFTING AND SOME WEAK UPPER SHRTWV ENERGY MOVING
ACROSS THAT AREA.  THE LATEST SFC ANALYSIS SHOWS A SFC LOW LOCATED
OVER SOUTHEAST NEW MEXICO...WITH A DEVELOPING WARM FRONTAL
BOUNDARY/DIFFERENTIAL HEATING ZONE FROM SOUTH OF GDP TO NEAR FST TO
NEAR DRYDEN.  A DRYLINE WAS ORIENTED NORTH-SOUTH FROM WEST OF FST
INTO THE BEND BEND REGION.

WITH LITTLE CLOUD COVER OVER SOUTHWEST TEXAS PRESENTLY...SCATTERED
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP IN AREAS WITH
BETTER DAYTIME HEATING...JUST EAST OF THE DRYLINE...IN AREAS OF
FAVORABLE LOW LVL SHEAR AND STEEP 850-500 MB LAPSE RATES.
THUNDERSTORMS THAT DO DEVELOP AREA EXPECTED TO MOVE NORTHEAST ACROSS
THE FORECAST AREA. THE ETA PROGS THE BEST 850 MB LOW LVL MSTR
CONVERGENCE...THE 850 MB THETA-E AXIS...AND MODERATE INSTABILITIES
(MUCAPES NEAR 2000 J/KG AND -4 TO -6 LI) SETTING UP FROM NEAR MAF
SOUTHWARD INTO THE EDWARDS PLATEAU REGION BY 00Z TONIGHT. THIS PROG
SEEMS REASONABLE CONSIDERING THE CURRENT LOCATION OF THE DRYLINE AND
EXPECTED SFC DEW POINTS ACROSS THE SOUTHERN PORTIONS OF THE FORECAST
AREA LATER THIS AFTERNOON AND EVENING.

WITH THE UPPER STORM SYSTEM IN AZ EXPECTED TO MOVE INTO NORTHERN
MEXICO LATER TODAY...I EXPECT THAT THERE WILL BE VERY LITTLE CHANGE
IN THE BROAD AREA OF SFC LOW PRESSURE LOCATED WEST OF OUR FORECAST
AREA.  UPSLOPE EAST TO SOUTHEAST LOW LVL FLOW WILL PERSIST ACROSS THE
FORECAST AREA EAST OF THE MOUNTAINS.  THUNDERSTORMS THAT DEVELOP
ACROSS THE NORTHEAST PORTIONS OF THE FORECAST AREA WILL BE THE
ELEVATED TYPE...WITH THE MAIN SEVERE WEATHER THREAT OVER THE ROLLING
PLAINS AND WESTERN PORTIONS OF THE BIG COUNTRY BEING LARGE HAIL.
FARTHER SOUTH...NEAR THE DEVELOPING WARM FRONT...DECENT DIRECTIONAL
SHEAR WILL EXIST WITH SR HELICITIES OF AROUND 200 M2/S2. THE
POSSIBILITY OF ISOLATED TORNADOES APPEARS TO EXIST IN THIS AREA.

AS A COLD FRONT MOVES INTO THE AREA TOMORROW...SHOWERS AND
THUNDERSTORM DEVELOPMENT WILL BE OF THE ELEVATED VARIETY ACROSS
THE FORECAST AREA...SIMILAR TO WHAT OCCURRED NORTH OF HERE EARLIER
TODAY.  THE MOST IMPRESSIVE AREAS OF ISENTROPIC LIFT...ALONG WITH THE
AXIS OF DEEPER MOISTURE ARE FORECAST TO SHIFT EAST OF THE AREAS
TOMORROW...WHICH ADD SOME CREDENCE TO THE SLIGHT DECREASE IN FAN POP
GUIDANCE THROUGH SUNDAY.  FOR NOW...WILL TREND POPS SLIGHTLY LOWER
FOR THE SECOND THROUGH FOURTH PERIODS.

FOR THE EXTENDED FORECAST...THE MRF CONTINUES TO MOVE THE UPPER
SYSTEM WELL INTO NORTHERN MEXICO...BEFORE SWING THE SYSTEM TOWARDS
DEEP SOUTH TEXAS TOWARDS THE WEDNESDAY OF NEXT WEEK.  FOR NOW...I
WILL MAINTAIN A CHANCE OF SHOWERS OR THUNDERSTORMS THROUGH TUESDAY...
WITH A SLIGHT WARMUP ON WEDNESDAY.

MY PREFERRED MODEL WAS THE ETA...WHICH DID A SLIGHTLY BETTER JOB
WITH THE TIMING OF THE ADVANCING COLD FRONT INTO THE FORECAST AREA.

PRELIMINARY CCF...
MAF  48/66/43/63  5332
LSA  44/61/40/59  5332
E41  49/63/46/61  5332
6R6  57/77/55/70  5232
MRF  42/68/36/62  3232
CNM  44/67/41/64  4332

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

PV

NMZ027>029-033-034-TXZ045>048-050>053-057>063-067>070-074-075-
079>082-258-312200-

THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX
1235 PM CST FRI MAR 31 2000

THE THREAT FOR SEVERE THUNDERSTORMS EXISTS THIS AFTERNOON AND
TONIGHT FOR MUCH OF THE FORECAST AREA.  IN THE EARLY
AFTERNOON...INITIAL THUNDERSTORM DEVELOPMENT IS EXPECTED TO BE IN THE
MOUNTAINOUS AREAS THEN MOVE TO THE NORTHEAST INTO THE PLAINS.
LATER IN THE AFTERNOON...THE DRYLINE IS EXPECTED TO MOVE EAST OF THE
MOUNTAINS AS WELL AND WILL SERVE AS A FOCUS FOR DEVELOPMENT.
ABUNDANT SUNSHINE OVER THE TRANS PECOS REGION WILL ALSO HELP TO
BUILD THUNDERSTORMS THIS AFTERNOON.  CHANCES FOR THUNDERSTORMS IN THE
NORTHEASTERN SECTIONS OF THE OUTLOOK AREA WILL PRIMARILY BE AFTER
SUNSET.

THE PRIMARY THREAT TO THE ENTIRE REGION WILL BE LARGE HAIL...UP TO
ABOUT 2 INCHES IN DIAMETER.  SOME STORMS MAY ALSO PRODUCE
POTENTIALLY DAMAGING DOWNBURST WINDS.  TORNADOES ARE POSSIBLE WITH
A FEW STORMS AS WELL...HOWEVER IN THE NORTHERN PARTS OF THE OUTLOOK
AREA...COLD AIR NEAR THE SURFACE WILL HAMPER TORNADO FORMATION.
PRESENT INDICATIONS SUGGEST THAT TORNADO FORMATION WOULD BE ISOLATED
AND MAINLY EAST OF THE MOUNTAINS AND MAINLY SOUTH OF A SEMINOLE TO
BIG SPRING LINE.

SPOTTER ACTIVATION MAY BE REQUESTED LATER THIS AFTERNOON THROUGH
THIS EVENING.

MATHEWS