Severe Thunderstorm Warning 23, NWS Midland/Odessa, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIDLAND TX
200 PM CDT MON APR 12 1999

MODELS HAVING DIFFICULTY HANDLING THE TIMING AND TRACK OF THE UPPER
LOW PRESENTLY ALONG THE SRN CA COAST...AS USUAL. ETA CONTINUES TO
BRING THE SYSTEM INLAND AND ACROSS THE SWRN STATES MUCH TOO
QUICKLY. THE 12Z AVN HAS NOW SPED THINGS UP OVER THE 00Z RUN...AND I
DONT LIKE THE LOOK OF THIS...EITHER. I PREFER THE SLOWER NGM...
WHICH WOULD NOT BRING THE SYSTEM INTO THE MAF CWA UNTIL SOMETIME
WEDNESDAY. NGM AND AVN MOS GUIDANCE HAVE BEEN ALL OVER THE PLACE
WITH THEIR POPS DURING THE PAST FEW RUNS...AND THESE NUMBERS NEED TO
BE SCRUTINIZED WITH CARE. 12Z MODEL POPS NOW MUCH...MUCH LOWER THAN
THEIR 00Z COUNTERPARTS. WOULD NOT BE SURPRISED TO SEE THE MODELS
FLIP FLOP ON THE VALUES AGAIN WITH THE 00Z RUN TONIGHT.

LOOKS TO ME LIKE THE BEST CHANCE FOR CONVECTION THIS AFTERNOON
AND TONIGHT WILL BE ACROSS THE MOUNTAIN ZONES. THESE STORMS WILL
LIKELY DRIFT INTO THE PLAINS...BUT I AM NOT TOO EXCITED ABOUT THE
INSTABILITY IN THESE AREAS. MODIFYING THE 12Z MAF SOUNDING TO REFLECT
CURRENT TRENDS...MEAN PARCEL LIS ONLY TOP OUT AROUND -1 WITH
RELATIVELY LOW CAPE VALUES...AND QUITE A BIT OF CIN TO OVERCOME.
WOULD NOT BE SURPRISED TO SEE SHOWERS AND TSTMS OVER THE PERMIAN
BASIN TONIGHT...BUT I BELIEVE THE THREAT OF SVR SHOULD BE DOWNPLAYED.
THE ONLY AREA THAT I AM CONCERNED ABOUT THIS EVENING IS IN THE AREAS
IMMEDIATELY ADJACENT TO THE SW MOUNTAIN ZONES...AND IN THE SE AROUND
TERRELL COUNTY. LOW LEVEL MOISTURE IS MUCH MORE ABUNDANT DOWN THERE.
AFTERNOON/EARLY EVENING MEAN PARCEL LIS SHOULD TOP OUT IN THE -3 TO
-5 RANGE...WITH CAPE VALUES APPROACHING 2000 J/KG. WILL MENTION SOME
STORMS POSSIBLY SEVERE IN THESE AREAS TONIGHT.

LOW LEVEL MOISTURE SHOULD CONTINUE TO INCREASE E OF THE MOUNTAINS
TONIGHT...AS SELY LOW LEVEL FLOW CONTINUES. FEEL THAT THIS MOISTURE
INCREASE WILL LEND TO MUCH BETTER CHANCES FOR CONVECTION TUESDAY AND
TUESDAY NIGHT. I THINK THAT THE MOST SIGNIFICANT THREAT FOR SEVERE
WEATHER WILL BE LATE TUESDAY AFTERNOON INTO TUESDAY NIGHT. STRONG
SLY LOW LEVEL JET SETS UP OVR W TX WITH SFC BOUNDARY/DRYLINE
PUNCHING IN FROM THE WEST LATE IN THE DAY. WITH UPPER LOW
APPROACHING...THERE SHOULD BE FAVORABLE UPPER LEVEL DIFLUENCE IN
PLACE. LOOKS LIKE A GOOD POTENTIAL FOR MULTICELL SVR STORMS.

LOOKING AHEAD INTO WEDNESDAY...UPPER LOW SHOULD PASS ACROSS
THE AREA DURING THE DAY W GUSTY WLY WINDS BEHIND THE WEAK PAC FRONT.
TEMPS SHOULD BE JUST A BIT COOLER WITH PERHAPS A FEW LINGERING
SHOWERS E OF THE MTNS DURING THE EARLY PART OF THE DAY.

PRELIM TEMPS/POPS...
MAF 054/079/052/073 3352
CNM 050/078/048/072 3342
MRF 044/076/043/068 3231
P07 058/081/055/075 3352

DJK