Flash Flood Warning 74, NWS Midland/Odessa, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIDLAND TX
212 PM CDT MON JUN 21 1999

NEARLY SATURATED...TROPICAL AIRMASS REMAINS IN PLACE ACROSS THE CWA
AGAIN TODAY...WITH ABOUT THE SAME GENERAL SYNOPTIC SCALE PATTERN AS
YESTERDAY. AM CONCERNED ABOUT THE POTENTIAL FOR HEAVY RAINFALL WITH
THE RELATIVELY WEAK WINDFIELD PRESENT...BUT DO NOT SEE ANY OBVIOUS
TRIGGERING MECHANISMS THAT WOULD RESULT IN WIDESPREAD CONVECTIVE
DEVELOPMENT. THE WEAK TROF AND VORT MAX OVER SE NM THAT HAVE BEEN
SUPERIMPOSED UPON THE RIDGE HAVE BEEN A CONCERN TO US THE PAST FEW
DAYS...AND THESE FEATURES ARE STILL SHOWING UP ON THE MODELS.
HOWEVER...I CANNOT SEE ANY EVIDENCE OF CIRCULATION ON THE WATER
VAPOR IMAGERY. LAST FEW FRAMES OF IR AND VISIBLE IMAGERY HINT AT SOME
CIRCULATION IN THE VICINITY OF ANDREWS/GAINES COUNTY...BUT THIS COULD
BE A RESULT OF CLOUD MOTIONS AT DIFFERENT LEVELS GIVING THE
APPEARANCE OF CIRCULATION. ONLY OTHER THING OF NOTE THIS AFTERNOON IS
WHAT APPEARS TO BE A WEAK HIGH-LEVEL DEFORMATION AXIS STRETCHING TO
THE NW-SE ACROSS THE AREA...RESULTING MAINLY FROM THE BROAD SCALE
ANTICYCLONIC CIRCULATION ACROSS NORTHERN MEXICO. STORMS SEEM TO BE
DEVELOPING ALONG THIS DEFORMATION AXIS TO THE SE...AND HAVE BEEN
SLOWLY DEVELOPING NWWD ALONG THIS AXIS. WILL HAVE TO KEEP A EYE ON
THIS TO SEE IF DEVELOPMENT CONTINUES NWWD INTO THE MAF CWA.

WILL FORGE AHEAD WITH THE RELATIVELY CONSERVATIVE PCPN FORECAST...
CONSIDERING THE AMOUNT OF MOISTURE THAT IS IN THE ATMOSPHERE. WILL
BASICALLY FOLLOW EXISTING FORECAST THAT IS IN PLACE FOR TONIGHT AND
TOMORROW...WITH 30 AND/OR 40 POPS MOST AREAS. LOCALIZED HEAVY
RAINFALL IS A DEFINITE POSSIBILITY...BUT IT WILL PROBABLY NOT BE TOO
WIDESPREAD. LOOKING AHEAD TOWARD TOMORROW NIGHT AND WEDNESDAY...
MODELS KEEP THE RIDGE CENTERED OVER NORTHERN MEXICO WITH ANTICYCLONIC
CIRCULATION CONTINUING ACROSS THE AREA. UPPER LEVEL FLOW PATTERN
BECOMES MORE WLY/NWLY...WITH MODELS FORECASTING THE WEAK SHORTWAVE
THAT IS PRESENTLY SUPERIMPOSED UPON THE RIDGE TO MOVE EASTWARD AND TO
REGAIN SOME OF ITS DEFINITION. I BELIEVE THIS WILL PROVIDE MORE OF AN
IMACT ON AREAS TO THE EAST. IT APPEARS THAT THERE WILL STILL BE
PLENTY OF MID AND HIGH LEVEL MOISTURE CAUGHT UP IN THE RIDGE OVER
NORTHERN MEXICO...AND THIS WILL PROBABLY KEEP A MODERATE AMOUNT OF
CLOUDINESS AROUND THE CWA.

PRELIM NUMBERS...
MAF 65/88/66/91 3332
CNM 68/91/66/94 3321
MRF 59/83/59/86 4331
P07 67/88/68/90 3332

DJK