Severe Thunderstorm Warning 157, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
220 PM CDT SAT AUG 10 2002

FORECAST CHALLENGE TONIGHT TO BE POPS OVERNIGHT...

ZONAL FLOW ALOFT TO PRODUCE HEIGHT FALLS TO THE WEST WITH AREAS OF
LOW PRESSURE REDEVELOPING ALONG THE FRONT RANGE. LEESIDE TROUGH MOVES
EAST TONIGHT WITH MOISTURE THE MAIN LIMITING VARIABLE FOR THE
DEVELOPMENT OF THUNDERSTORMS. COND PRES DEF ARE 100+ TIL AFTER 03Z
WITH NARROW CORRIDOR FOR THE POTENTIAL STORM DEVELOPMENT BY 06Z AS
H85 JET DEVELOPS FROM THE SOUTH WITH WINDS INCREASING TO 35 KNOTS BY
09Z. H5 FLOW WOULD CARRY STORMS TO THE EAST NORTHEAST WITH ISOLATED
THUNDERSTORMS INCLUDED AFT 03Z AS WARM FRONT LIFTS NORTHEAST.

SUNDAY THE LEESIDE TROUGH EVOLVES WITH DRYLINE TO PUSH EAST DURING
THE DAY. ATMOSPHERE WILL BECOME INCREASINGLY UNSTABLE IN THE
AFTERNOON WITH BEST MOISTURE ADVECTION TO THE EAST OF THE FORECAST
AREA BY EVENING. MODEL TIMING WILL MAKE THE DIFFERENCE WITH LOW POPS
FOR THE NORTH CENTRAL INTO THE EVENING. THEN OVERNIGHT THE COLD FRONT
PUSHES SOUTH ACROSS THE AREA. H85 WINDS TO 40 KNOTS INDICATED WITH
NORTH WINDS TO KEEP AIR MIXED AS DEWPOINTS ON ETAX PROGGED INTO THE
MID 30S ACROSS THE WEST BY MONDAY MORNING.

MONDAY SURFACE HIGH RIDGES SOUTH WITH LIGHT NORTHEAST WINDS FOR THE
DAY. COLD AIR ADVECTION OCCURS THROUGH THE DAY WITH BLEND OF
GUIDANCE NUMBERS FOLLOWED WITH READINGS IN THE 70S. A COOLER START
ON TUESDAY AS THE SURFACE HIGH BUILDS SOUTH WITH TEMPERATURES ABOUT
5 DEGREES WARMER THAN MONDAY. GUIDANCE NUMBERS POSSIBLY TOO COOL
CONSIDERING FULL SUN FOR THE DAY.

WEDNESDAY SOUTH WINDS RETURN WITH LEESIDE TROUGH REFORMING TO THE
WEST. H85 TEMPERATURES RISE INTO THE UPPER 20S WEST WITH FRONT TO
DESCEND SOUTH DURING THE OVERNIGHT HOURS.

INTO THE EXTENDED THE H5 CLOSED LOW OVER CENTRAL CANADA WILL DROP
SOUTHEAST TO OVER ONTARIO THURSDAY THEN LIFT TO EAST OF THE
HUDSON BAY ON SUNDAY. TWO FRONTS WILL DRIVE THROUGH THE PLAINS AS THE
UPPER LOW TRANSITS THROUGH THE CANADIAN PROVINCES...ONE MOVING
THROUGH THE FORECAST AREA THURSDAY MORNING...THEN A SECONDARY FRONT
TO MOVE ACROSS BY SATURDAY MORNING. THURSDAY MAIN FORCING WILL CLIP
THE NORTH CENTRAL WHILE THE WEST REMAINS UNDER NORTHWEST FLOW WITH
MOISTURE LIMITED. SATURDAY LOOKS MORE PROMISING FOR SHOWERS AND
THUNDERSTORM AS MOISTURE SURGES NORTH WITH INCREASED LOW LEVEL
CONVERGENCE OVER THE FORECAST AREAS. COLD FRONT DRIFTS SOUTH ACROSS
KANSAS SATURDAY WHILE THE CANADIAN HIGH BUILDS ACROSS THE NORTHERN
MIDWEST WITH UPSLOPE FLOW TO HELP SATURATE THE LOWER LAYERS WITH MORE
CLOUDS WHICH SHOULD HELP HOLD TEMPERATURES DOWN. WILL INCREASE CLOUDS
ACROSS THE NORTH CENTRAL WEDNESDAY NIGHT AND THURSDAY MORNING WITH
LOW POPS. SATURDAY CLOUDS WILL INCREASE WITH THE PASSAGE OF THE FRONT
AND WILL INTRODUCE LOW POPS ACROSS ALL OF THE FORECAST AREA.
OTHERWISE WEDNESDAY AND FRIDAY SHOULD BE DRY TEMPERATURES BLEND OF
GUIDANCES.

.LBF...NONE.

KECK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE, NE
810 PM CDT SAT AUG 10 2002

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

0800 PM    2 N MULLEN              NE       1.00 INCH HAIL
08/10/02   HOOKER                           REPORTED BY PUBLIC

TRM

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE, NE
810 PM CDT SAT AUG 10 2002

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

0800 PM    2 N MULLEN              NE       1.00 INCH HAIL
08/10/02   HOOKER                           REPORTED BY PUBLIC

TRM