Severe Thunderstorm Warning 195, NWS Fort Worth, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
320 PM CDT FRI JUN 29 2001

SEVERAL DAYS AGO...A PATTERN WAS SETTING UP FOR WHAT I THOUGHT WOULD
BE A CHANCE FOR FAIRLY GENERAL RAINS ACROSS NORTH TEXAS.  A RATHER
VIGOROUS LOW PRESSURE CENTER ALOFT...WAS SLOWLY APPROACHING FROM THE
NORTHEAST...COMBINED WITH DECENT MOIST INFLOW FROM THE SOUTH. THE
INCREASE IN NORTHERLY FLOW ALOFT ON THE WEST SIDE OF THE UPPER LOW IS
A PATTERN THAT OFTEN RESULTS IN SOME NOCTURNAL STORMS...BECAUSE OF
STRONG STORM-RELATIVE MOISTURE CONVERGENCE FOR THE HIGH-BASED STORMS
...PROVIDED BY THE ENHANCED NOCTURNAL LOW-LEVEL JET AND THE SOUTHWARD
MOTION OF THESE STORMS.

THIS PROCESS HAS HAPPENED...BUT THE ACTIVITY HAS BEEN EXTREMELY
CONCENTRATED ACROSS EASTERN OKLAHOMA AND NORTHEAST TEXAS BY AN 850
MB FRONTAL ZONE.  THE THERMAL CONTRAST ZONE HAS PROVIDED
SIGNIFICANT UPLIFT (SEEN ON THE 305 DEGREE K ISENTROPIC SURFACE BY
THE PRESSURE ADVECTION TERM) WITHIN THE LIMITED AREA THAT HAS BEEN
BATTERED BY HEAVY NIGHTTIME AND MORNING CONVECTIVE RAINFALL. INSTEAD
OF MORE WIDESPREAD AND SCATTERED STORMS...WE HAVE SEEN LOCAL
CONCENTRATIONS OF HEAVY RAIN...REPEATEDLY OVER THE SAME AREA.

THIS PATTERN WILL BREAK DOWN SATURDAY NIGHT...AS A WEAKER LOW
PRESSURE CENTER ALOFT FORMS OVER SOUTH TEXAS.  THUS...WE WILL GO FOR
VERY HIGH POPS TONIGHT IN THE NORTHEAST (AGAIN)...AND GRADUALLY
LOWER RAIN CHANCES IN THAT AREA THROUGH THE WEEKEND. DAYTIME OUTFLOW
BOUNDARIES FROM THE OVERNIGHT STORMS HAVE BEEN ADEPT AT PRODUCING
SCATTERED STORMS ONLY IN EAST TEXAS DURING THE PAST AFTERNOONS...
BECAUSE OF A WEAKER CAPPING INVERSION IN THAT AREA. THIS WILL
CONTINUE...WITH LOWER RAIN CHANCES ELSEWHERE.  RAIN WILL BE MINIMAL
MONDAY THROUGH WEDNESDAY...WITH NORTHWEST FLOW ALOFT AND AN
APPROACHING FRONT RESULTING IN INCREASING RAIN CHANCES NEXT THURSDAY
...AND ESPECIALLY FRIDAY.

TEMPERATURES WILL WARM A BIT AS CLOUDS DECREASE THIS NEXT WEEK.

DFW 73/92/74/94 3221    ACT 74/94/73/93 1122

.FWD...NONE

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