Tornado Warning 37, NWS Hastings, NE

SOUTH CENTRAL NEBRASKA/NORTH CENTRAL KANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
250 PM CDT THU JUN 3 1999

MAIN CONCERN FOR THIS PACKAGE WILL BE PCPN TONITE AND SATURDAY AS
WELL AS IN THE OUTER PERIODS. S/WV THAT INDUCED TSRA ACROSS THE CWA
THIS MORNING HAS MOVED OFF TO THE EAST AND IS NOW LOCATED NEAR THE
IOWA/MO BORDER. MEANWHILE LATEST LAPS DATA SHOWING HIER
INSTABILITIES ACROSS SOUTHERN SECTIONS OF THE CWA WITH CAPES
NEARING 3700 J/KG...LIS AROUND -8 AND STRONG SOUTHERLY FLOW OF LL
MOISTR WITH DEW POINTS AROUND 70 DEG. PROBLEM IS THE LACK OF UPPER
LEVEL SUPPORT AND TRIGGERING MECHANISM TO INITIATE TS DEVELOPMENT.
WITH THIS IN MIND WILL GO WITH SMALL POPS TONITE. BUT IF SOMETHING
DOES DEVELOP...THE ATM SHOULD BE SUFFICIENTLY UNSTABLE AND JUICY TO
SUSTAIN POTENTIALLY HEAVY RAINFALL. WITH THIS SCENARIO IT WILL NOT
TAKE MUCH RAINFALL TO CAUSE SOME FLASH FLOODING MAINLY ACROSS
EASTERN SECTIONS OF THE CWA WHERE FFG IN SOME PLACES HAVE 1-3 HR
GUIDANCE VALUES UNDER AN INCH. FOR SAT DAYTIME HEATING WILL ALLOW
INSTABILITIES TO INCREASE ACROSS THE CWA SO WILL ONLY ADD TOKEN
SLIGHT CHANCE FOR LATE AFTN TS CONSIDERING AMOUNT OF MID LEVEL WAA
WHICH SHOULD DEVELOP RELATIVELY DECENT CAP. FRI NITE LEE SIDE LOW
STRENGTHENS OVER THE WESTERN HIGH PLAINS AND SOUTHERLY FLOW
CONTINUES TO DRAW IN ADDITIONAL MOISTR TO THE AREA. LAYER RH
INCREASE OVERNITE AS NEXT SYSTEM APPROACHES FROM THE CENTRAL
ROCKIES. BEST LIFT IS PROGGED BY 12Z SO WILL WORD FOR SMALL POPS
TOWARD DAYBREAK. ON SAT MOISTR HANGS AROUND AND WILL AGAIN GO WITH
SMALL POPS WITH INFLUENCE OF NEXT DISTURBANCE INTO THE REGION.

IN THE EXTENDED...NOT MUCH CHANGE MADE HERE AS TREND CONTINUES FOR
CHANCE OF THUNDERSTORMS. IN GENERAL...BY SUN 12Z MRF AND UKMET ARE IN
AGREEMENT WITH NEXT S/WV TROF OVER THE CENTRAL ROCKIES AND BY LATE
DAY MOVING IT INTO THE EASTERN DAKOTAS/WESTERN MIN. CANADIAN MODEL
AND NOGAPS ARE MORE PROGRESSIVE WITH THIS FEATURE AND DONT BY SOLN.
BECAUSE OF THE TIMING OF THE DISTURBANCE...STRONG DPVA AND LINGERING
INSTABILITIES WILL WORD FOR EARLY TS. AFTERWHICH...DRIER MORE STABLE
AIR ADVCTS INTO AREA BY SUNDAY NITE FOR PLEASANT CONDITIONS DURING
THE NITETIME HOURS AND MOST OF MONDAY. TSRA CHANCES LOOK GOOD DURING
THE OVERNITE HOURS ON MONDAY AND ESPECIALLY TUESDAY AS INSTABILITIES
ONCE AGAIN ARE ON THE INCREASE FROM DAYTIME HEATING AND MOISTR
ADVECTING INTO THE AREA VIA SOUTHERLY FLOW.

.GID...NONE

DEE