Flash Flood Warning 7, NWS Topeka, KS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
300 PM CDT WED JUL 29 1998

RAINFALL CHANCES/AMOUNTS MAIN FORECAST PROBLEMS THIS CYCLE

COMPLEX SURFACE PATTERN OVER KS, OK, AND NE.  TWO BOUNDARIES TO
WORRY ABOUT AND HEAVY RAINFALL POSSIBLE FROM BOTH OF THEM.  OBSERVED
AND FORECAST SOUNDINGS INDICATE GOOD MOISTURE WITH HIGH PW'S AND
DEEP WARM CLOUD LAYER.  BOTH ETA AND AVN SHOW DEEP LAYER FORCING FOR
VERTICAL MOTION ACROSS NERN KS TONIGHT INTO THURSDAY.  LOW-LEVEL
POSITIVE THETA-E ADVECTION ALSO PRONOUNCED IN THE AREA AND MCS
DEVELOPMENT MACROS POINT TO GOOD POSSIBILITY OF DEVELOPMENT FROM
CENTRAL INTO EAST CENTRAL KS TONIGHT.  ADDITIONALLY, RADAR PRECIP
ESTIMATES FROM LAST NIGHT APPEARED TO BE ONLY ABOUT 60 PERCENT OF
OBSERVED VALUES SO CONTINUED PRECIPITATION EFFICIENCY EXPECTED
TONIGHT.  FOR ALL THE ABOVE REASONS PLUS RELATIVELY LOW FFG VALUES,
WILL ISSUE A FLASH FLOOD WATCH FOR CWA TONIGHT.

FORCING CONTINUES ON THURSDAY AND HIGH POPS CONTINUED THEN AS
NEBRASKA BOUNDARY SAGS SWD INTO KS.  APPEARS MAIN FORCING WILL EXIT
NORTHERN KS LATE THURSDAY NIGHT AND EARLY FRIDAY AS FRONT CONTINUES
SAGGING SWD INTO OK AND UPPER SHORTWAVE TROUGH MOVES SOUTHEAST.
TEMPERATURES BEHIND FRONT SHOULD BE SLIGHTLY COOLER THAN FWC
GUIDANCE IN CLOUDS/RAIN AND NORTHEAST WINDS.

.TOP...FLASH FLOOD WATCH FOR NC, NE, AND EC KS TONIGHT
GDP