Severe Thunderstorm Warning 206, NWS Topeka, KS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
305 PM CDT SUN AUG 11 2002

...MAIN CONCERN IS PRECIP CHANCES TONIGHT THROUGH TUESDAY...

LAPS INDICATES LITTLE TO NO CAP OVER SOUTHEAST 2/3 OF CWA AND WEAK
CONVERGENCE AND SURFACE HEATING IS CAUSING CLUSTERS OF SHOWERS AND
STORMS TO DEVELOP IN CONDITIONALLY UNSTABLE ENVIRONMENT.  SURFACE
BASED CAPE OVER 3000 J/KG BUT SHEAR IS RELATIVELY WEAK.  THUS EXPECT
STORMS TO WEAKEN/DISSIPATE BY SUNSET.  HOWEVER, A WEAK VORT MAX
MOVING EASTWARD ACROSS EXTREME SRN NEBRASKA/NRN KS MAY FIRE OFF MORE
CONVECTION LATER TONIGHT AS LOW-LEVEL JET STRENGTHENS.  THUS HAVE
LOW POPS FOR ALL OF CWA TONIGHT.

MODEL SURFACE FORECASTS IN SHORT RANGE HAVE VERY SIMILAR TIMING WITH
TROUGH/FRONT PASSAGE THROUGH EASTERN KANSAS MONDAY THROUGH MONDAY
NIGHT, IN ASSOCIATION WITH UPPER SHORTWAVE TROUGH MOVING SOUTHEAST
ACROSS CENTRAL PLAINS.  WHILE DIFFERENCES EXIST IN MODEL PRECIP
FORECASTS TONIGHT INTO EARLY MONDAY...THEY ARE VERY SIMILAR WITH
GENERATING SIGNIFICANT RAINFALL FROM MONDAY AFTERNOON THROUGH
TUESDAY MORNING ACROSS CWA.  THUS HIGHEST POPS WILL BE DURING THAT
PERIOD.

SINCE MODELS TIMING OF TROUGH CONSISTENT WITH EACH OTHER, TIMING OF
DRY WEATHER FOR TUESDAY NIGHT INTO THURSDAY ALSO LOOKS VERY GOOD,
AND IS CONSISTENT WITH GOING FORECAST.  12Z AVN AND 00 MRF HINT AT
PRECIP RETURNING THURSDAY NIGHT OR FRIDAY ASSOCIATED WITH WEAK
SHORTWAVE AND WARM ADVECTION.  WILL KEEP DRY FORECAST GOING AS NOT
CONFIDENT WEAK SYSTEM DAY 5 JUSTIFIES ADDING POPS.  WHILE MRF WOULD
BRING PRECIP BACK NEXT SUNDAY WITH ANOTHER FRONTAL PASSAGE, TIMING
OF SYSTEM DAY 7 QUESTIONABLE AND 00Z MRF 500 MB FORECAST FOR THAT
TIME INCONSISTENT WITH ENSEMBLE MEAN.

BIGGEST TEMPERATURE PROBLEMS FOR MON AND TUES WITH WIDE VARIATION IN
GUIDANCE FORECASTS, PARTICULARLY MONDAY.  ETA MOS GOES 97 FOR MHK ON
MONDAY WHILE MAV GOES 82.  WILL NOT GO TOWARD EITHER EXTEME BUT
EXPECT HIGHS TO BE NEAR OR ABOVE FWC VALUES IN UPPER 80S TO LOW
90S.  COOL DAY ON TUESDAY BEHIND FRONT WITH 70S IN CLOUDS, RAIN
AND NORTHERLY WIND.

TOP...NONE

60

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TOPEKA KS
450 PM CDT SUN AUG 11 2002

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

0345 PM    CORNING                   KS    65 MPH TSTM GUST
08/11/02   NEMAHA                          REPORTED BY A SPOTTER.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TOPEKA KS
615 PM CDT SUN AUG 11 2002

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

0600 PM    WAMEGO                    KS    1 INCH HAIL
08/11/02   POTTAWATOMIE                    REPORTED BY A SPOTTER.