Severe Thunderstorm Warning 284, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
205 PM CDT WED AUG 29 2001

...THE FORECAST CHALLENGES ARE PRECIPITATION CHANCES TONIGHT AND
TEMPERATURES OVER THE NEXT FEW DAYS...

WATER VAPOR IMAGERY SHOWS A H5 TROUGH MOVING THROUGH SERN MT AND WRN
NORTH DAKOTA. A CYCLONIC VORT CENTER CONTINUES TO MOVE THROUGH SERN
SD WHICH HAS HELPED TO KICK OFF CONVECTION OVER MINN THIS MORNING.
MODELS AT H5 INDICATED A TROUGH OVER THE DAKOTAS WITH A WEAK LOW
EXTENDING SOUTH INTO WEST TEXAS. AN OTHERWISE ZONAL FLOW EXISTS OVER
THE REMAINDER OF THE CONUS. AT 18Z THE LEADING EDGE OF THE COLD
FRONT EXTEDED FROM NEAR MERRIMAN TO SCOTTSBLUFF. THR GREATEST
PRESSURE RISES ARE OCCURING IN WESTERN SOUTH DAKOTA. MOST HIGHS IN
THE FA IN THE UPPER 80S TO AROUND 90. SURFACE TROUGH EXTENDS FROM
WEST OF HON SD THROUGH SNY NEBR.

TONIGHT...BOTH THE ETA AND AVN SHOW RATHER STRONG H85 TO H7 2-D
FRONTOGENESIS BY 00Z OVER THE NORTHWEST CWFA...THEN FOCUSING INTO
THE CENTRAL CWFA BY 06Z. PRECIPITABLE WATER VALUES WILL INCREASE
AHEAD OF THE SURFACE FRONT THIS EVENING AND RISE TO ABOUT 1.3 INCHES
IN THE EASTERN CWFA. THE ETA AND AVN SHOW THE SURFACE FRONT CLEARING
THE CWFA BY 12Z. WILL BOOST CURRENT POPS IN CUSTER COUNTY AND LOWER
POPS A BIT IN THE NORTHWEST. ALL OTHER POPS LOOKING ON TRACK.

THURSDAY...MORNING POPS NEEDED IN THE SOUTHERN CWFA UNTIL FRONT IS
WELL CLEAR OF THE AREA. THE AVN SHOWS A VORT MAX MOVING THROUGH
NORTHEASTERN COLORADO WITH UPSLOPE NORTHEAST WINDS EXTENDING INTO
THE SOUTHWEST. BY AFTERNOON ALL AREAS WILL BE UNDER THE INFLUENCE OF
SURFACE HIGH PRESSURE AND SUBSIDENCE. AS SURFACE HIGH BUILDS
IN...NORTHEAST WINDS WILL VEER TO THE EAST AND SOUTHEAST OVER THE
WESTERN CWFA IN THE AFTERNOON. HIGHS WILL BE CONSIDERABLY COOLER
RANGING IN THE UPPER 70S TO AROUND 80.

THURSDAY NIGHT...FRONT STALLS OUT ACROSS KANSAS KEEPING ANY CHC FOR
SHOWERS TO OUR SOUTH. TO REMAIN PARTLY CLOUDY SOUTH WITH THE BEST
MOISTURE IN THE 850 TO 700 MB LAYER. MOSTLY CLEAR NORTHEAST WITH
LIGHT SOUTHEAST WINDS OVER THE CWFA.

FRIDAY...BOTH THE ETA AND AVN AGREE ON A VORT MAX MOVING FROM
SOUTHERN WY INTO THE NEBRASKA PANHANDLE. LOOKS TO BE A FRIDAY NIGHT
EVENT FOR THE WEST AND WILL NOT INCLUDE AFTERNOON POPS FAR WEST
ATTM. AS LEESIDE TROUGH DEVELOPS AND SURFACE HIGH TO OUR EAST SLIDES
SOUTHEAST...GOOD WAA WILL PUSH TEMPS INTO THE UPPER 80S FAR SOUTHERN
COUNTIES TO NEAR 80 NORTHEAST.

FRIDAY NIGHT...THE VORT MAX MOVES SOUTHEAST THROUGH THE SOUTHWEST
CWFA AND WILL INCLUDE A CHANCE OF THUNDERSTORMS THERE. WITH BEST
THETA-E RESIDING OVER THE HIGHS PLAINS INTO THE WESTERN CWFA WILL
LEAVE THE EAST DRY.

EXTENDED...LOOKS DRY WITH THE EXCEPTION OF LATE FRIDAY INTO SATURDAY
WITH GOOD THETA-E RIDGE ALONG THE HIGHS PLAINS. THE MRF SHOWS A VORT
MAX RIDING THE UPPER RIDGE ACROSS WYOMING ON FRIDAY AND ACROSS
WESTERN NEBRASKA SATURDAY. WILL KEEP CHANCES OVER THE EASTERN CWFA
DESPITE LIKELIHOOD THAT CONVECTION MAY DISSIPATE AS IT MOVE EAST OF
THE THETA-E RIDGE INTO SURFACE HIGH PRESSURE.  WILL KEEP THE SUNDAY
THROUGH WEDNESDAY PERIOD DRY. TEMPS TO RETURN TO SLIGHTLY ABOVE
NORMAL IN THE 80S.

.LBF...NONE.

ROBERG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE, NE
609 PM CDT WED AUG 29 2001

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0601 PM    AINSWORTH                 NE   1.75 INCH HAIL
08/29/01   BROWN

MP

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE, NE
624 PM CDT WED AUG 29 2001

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0605 PM    6 NNE BASSETT             NE   .75 INCH HAIL
08/29/01   ROCK

MP

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE, NE
709 PM CDT WED AUG 29 2001

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0650 PM    ELSMERE                   NE   1.75 INCH HAIL
08/29/01   CHERRY

MP