Tornado Warning 18, NWS Midland/Odessa, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIDLAND TX
200 PM CDT FRI APR 30 1999

SIGNIFICANT CONVECTION CONTINUING THIS AFTERNOON. AIRMASS ACROSS THE
AREA REMAINS MOIST AND UNSTABLE...AND A SERIES OF SHORTWAVES
ROTATING AROUND THE UPPER LOW OVER AZ WILL LIKELY KEEP CONVECTION
ACTIVE ACROSS THE AREA THROUGH THIS EVENING. AXIS OF THE THETA-
E RIDGE ACROSS THE AREA REMAINS ROUGHLY ACROSS THE MIDDLE SECTION OF
THE CWA...AND PROGS GRADUALLY SHIFT THIS INTO THE EASTERN CWA BY
TOMORROW AFTERNOON. UPPER LEVEL DIFLUENCE ACROSS THE CWA WAS QUITE
IMPRESSIVE THIS MORNING. AREA OF BEST DIFLUENCE WILL PROPOGATE INTO
NORTHERN TX AND SOUTHERN OK LATE TONIGHT. DRYLINE TO THE WEST HAS
BEEN ADVANCING VERY SLOWLY THROUGHOUT THE DAY...WITH STORMS FIRING
UP ALONG ITS BOUNDARY CONTINUOUSLY AND TRAINING NWD AND NEWD. LOOKS
AS IF A NARROW DRY SLOT OVR FAR WEST TX WILL BEGIN ROTATING INTO THE
AREA LATER TONIGHT...AFFECTING PORTIONS OF THE CWA UNTIL EARLY
MORNING. WILL STILL KEEP SCT POPS IN AREA OVERNIGHT WITH THE MOIST
AIRMASS AND PVA ALOFT...BUT WILL NEED TO KEEP THIS IN MIND.

MODELS SLOWLY ADVANCE THE LOW AND BEGIN LIFTING IT OUT LATE
TOMORROW. MODELS ALWAYS TRY TO LIFT THESE UPPER LOWS OUT TOO
QUICKLY...SO I WILL TAKE THIS INTO ACCOUNT WITH THE FORECAST. BY
MIDDAY TOMORROW...IT LOOKS AS IF THE UPPER LEVEL FLOW WILL BECOME
MORE SWLY WITH THE APPROACH OF THE LOW...AND THIS SHOULD HELP THE
DRYLINE PUSH FURTHER EWD. WITH THE MOIST AIRMASS AND UPPER LEVEL
DISTURBANCES PROPOGATING AROUND THE LOW...WILL NEED TO KEEP POPS UP
FOR TOMORROW. TOMORROW NIGHT THE LOW WILL STILL BE IN THE VICINITY...
AND WILL KEEP POPS IN AS WELL.

THE MAIN CHALLENGE WILL BE WHAT TO DO WITH SUNDAY. MODELS LIFT LOW
AND ASSOCIATED VORT ENERGY NWD AWAY FROM THE AREA...AND DRIER SFC
AIR IS PROGGED TO OVERRUN THE AREA. HOWEVER...CONSIDERING THE FACT
THAT THE LOW WILL PROBABLY MOVE OUT MORE SLOWLY...WILL HAVE TO KEEP
SOME CLOUDS AROUND DURING THE DAY...AND POSSIBLY EVEN SOME LINGERING
MORNING POPS.

LBB...WORKZONES FORTHCOMING...WILL BE A FEW MINUTES LATE.

PRELIM TEMPS/POPS
MAF 57/75/54/79 6542
CNM 51/75/47/80 543-
MRF 45/74/41/78 222-
P07 60/78/59/79 3431

DJK

NMZ027>029-TXZ045>048-050>052-057>063-067>070-074-075-079>082-010000-

THUNDERSTORM OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MIDLAND TX
1058 AM CDT (958 AM MDT) FRI APR 30 1999

THIS OUTLOOK PERTAINS TO THE FOLLOWING COUNTIES IN WEST TEXAS:

ANDREWS   CULBERSON  GLASSCOCK   MARTIN    REAGAN   UPTON
BORDEN    DAWSON     HOWARD      MIDLAND   REEVES   WARD
BREWSTER  ECTOR      JEFF DAVIS  PECOS     SCURRY   WINKLER
CRANE     GAINES     LOVING      PRESIDIO  TERRELL

AND IN SOUTHEAST NEW MEXICO:

EDDY      LEA

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE AREA
TODAY AND TONIGHT...

SYNOPSIS: AN UPPER LEVEL STORM SYSTEM SPINNING OVER THE SOUTHWESTERN
U.S. WILL EJECT ANOTHER PIECE OF ENERGY ACROSS THE OUTLOOK AREA
TODAY.  MEANWHILE...A STATIONARY FRONT WAS LOCATED NEAR A ROSWELL...
MIDLAND...TO WACO LINE THIS MORNING AND IS EXPECTED TO MOVE LITTLE
THROUGHOUT THE DAY.  IN ADDITION...A DRYLINE EXTENDED SOUTHWARD FROM
THE FRONT ALONG THE MOUNTAINS OF WEST TEXAS AND SOUTHEAST NEW MEXICO.
THESE FEATURES WILL BECOME THE FOCUS FOR SEVERE WEATHER TODAY.

BREAKS IN THE CLOUDS WILL LET SUNSHINE TO WARM THE SURFACE OF THE
EARTH AND FURTHER DESTABILIZE THE ATMOSPHERE.  A JET STREAK PUNCHING
NORTHEASTWARD THROUGH NEW MEXICO...ALONG WITH THE APPROACHING UPPER
LEVEL ENERGY...WILL AID LIFT IN THE VICINITY OF THE DRYLINE.  THE
MOST SUSCEPTIBLE AREA FOR SEVERE THUNDERSTORMS THIS AFTERNOON WILL BE
OVER SOUTHEAST NEW MEXICO AND THE TRANS PECOS WHERE THE DRYLINE AND
STATIONARY FRONT ARE IN CLOSE PROXIMITY.  STORMS WILL MOVE TO THE
NORTH-NORTHEAST INTO PERMIAN BASIN LATER TODAY.

AS WINDS IN THE MID LEVELS OF THE ATMOSPHERE WILL REMAIN WEAK...
LARGE HAIL...STRONG WINDS...AND FLASH FLOODING WILL CONTINUE TO BE
THE MAIN SEVERE WEATHER THREATS.  HOWEVER...WITH SOME TURNING OF
THE WINDS...SUPERCELL DEVELOPMENT CAPABLE OF PRODUCING WEAK
TORNADOES WILL BE POSSIBLE...ESPECIALLY DURING AND AFTER MAXIMUM
DAYTIME HEATING.

SPOTTER ACTIVATION WILL LIKELY BE REQUIRED.

FOR THE WEST CENTRAL TEXAS OUTLOOK SEE PRODUCT LBBSPSSJT.