Severe Thunderstorm Warning 232, NWS Omaha, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA NE
240 PM CDT MON JUN 4 2001

THUNDERSTORMS WITH POTENTIAL FOR HEAVY RAIN MAJOR CONCERN WITH
TEMPERATURES SECONDARY.

WMFNTL BNDRY ACROSS FM LOW PRES CNTR E OF KDDC ACROSS E CNTRL KS AND
CNTRL MO HAS BEEN LIFTING NWD DURING DAY. BELIEVE BOUNDARY WILL
CONTINUE TO MOVE SLOWLY NWD THIS AFTN INTO THIS EVE BEFORE STALLING
LATER TNGT FM NE KS AND TO ALONG THE SRN IA NRN MO BORDER IN LINE
WITH 12Z MESTO ETA. WIDESPREAD SHOWERS AND THUNDERSTORMS LIKELY TNGT
VICINITY AND N OF FNT AS LOW LEVEL JET STRENGTHENS INCREASING STRONG
POSITIVE LOW LEVEL THETA E ADVECTION DURING EVENING THROUGH TONIGHT.
ALTHOUGH THUNDERSTORMS WILL BE MORE ELEVATED THAN ROOTED IN BOUNDARY
LAYER DEFINITE RISK FOR HEAVY RAIN EXISTS...REFERENCE QPFERD WHICH
LOOKS REASONABLE...AND WILL ISSUE A FLASH FLOOD WATCH FOR PTNS SE
NEB AND SW IA WHERE FLASH FLOOD GUIDANCE LOWER. ALSO BASED ON
EXPECTED INSTABILITY AND MID LEVEL LAPSE RATES POTENTIAL EXISTS FOR
SOME TSTMS TO REACH SEVERE CRITERIA WITH LARGE HAIL MAIN RISK. IN
ADDITION TO LIFING AND MOIST WARM ADVECTION OVER FRONT STRONG
SHORTWAVE PIVOTING ACROSS PLAINS OUT OF MID LEVEL LOW OVER MT WILL
PROVIDE ADDTIONAL UVV FOR ELEATED CONVECTIVE DEVELOPMENT AND SHOWERS
AND TSTMS TNGT FOR REST OF FCST AREA.

ON TUE MODELS TEND TO WEAKEN INFLOW INTO BOUNDARY DURNG MRNG HOURS
AS FLOW VEERS AND TEND TO MOVE FNTL BOUNDARY SE. WOULD APPPEAR THE
MAIN POTENTIAL FOR THUNDERSTORMS ON TUESDAY INTO TUESDAY EVENING
WILL BE FOCUSED IN VICINITY OF FRONTAL BOUNDAY MAINLY OVER SE NEB
AND SW IA. OTRW WEAK SURFACE RIDGE WITH SOMEWHAT DRIER AND MORE
STABLE AIR WILL BEGIN TO AFFECT NE NEB AND W CNTRL IA DURING DAY
TUE AND THEN ACROSS REST OF AREA LATER TUE NIGHT. WED APPEARS TO
START OUT DRY. HOWEVER S AND SELY RETURN FLOW OF BACK SIDE OF RIDGE
WITH INCREASE IN LOW LEVEL MOISTURE...LEADS TO SOME AIR MASS
DESTABILIZATION AND AT LEAST SMALL CHANCE OF A TSTM ESPCLY NW PTNS
OF FCST AREA LATE WED AFTN OR WED NIGHT. TAKING MORE OF AN AVERAGE
BEWTEEN WARMER FWC AND COOLER MAV GUIDNACE FOR MAX TEMPS APPEARS TO
CONTINUE TO BEST COURSE.

WITH UPPER RIDGE TENDING TO BUILD OUT OF SRN ROCKIES INTO CNTRL AND
NRN PLAINS EXTENDED TRENDS MAINLY DRY WITH WARMING TEMPS INTO
WEEKEND. HOWEVER NEED TO BE WATCHFULL FOR UPPER DISTUBANCES COMING
OVER RIDGE AND THEN MOVING SEWD ACROSS PLAINS GNERATING CONVECTIOjN.

.OMA...FLASH FLOOD WATCH...TONIGHT...NEZ044-045-050>053-065>068-
       078-088>093-IAZ055-056-069-079-080-090-091
WIESE

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-050600-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
520 PM CDT MON JUN 4 2001

STORM SPOTTER ACTIVATION COULD BE NEEDED THIS EVENING AND TONIGHT
OVER PARTS OF EASTERN NEBRASKA AND SOUTHWEST IOWA.

THE THREAT FOR SEVERE WEATHER WILL BE FROM 600 PM THIS EVENING
THROUGH 500 AM TUESDAY MORNING.  EVEN THOUGH THE GREATEST RISK OF
SEVERE IS SOUTH OF A COLUMBUS TO FREMONT TO HARLAN IOWA LINE...THERE
IS A THREAT OF LARGE HAIL JUST ABOUT ANYWHERE OVER EASTERN
NEBRASKA AND SOUTHWEST IOWA TONIGHT.  FLASH FLOODING IS ALSO A
THREAT AROUND AND SOUTH OF OMAHA AND COUNCIL BLUFFS.

A WARM FRONT STRETCHED FROM A SURFACE LOW IN CENTRAL KANSAS...INTO
CENTRAL MISSOURI SOUTHEAST OF KANSAS CITY.  EVEN THOUGH CONDITIONS
NORTH OF THE FRONT WERE COOL AND CLOUDY...RELATIVELY WARM...MOIST
AND UNSTABLE AIR WILL CONTINUE TO STREAM NORTH ABOVE THE COOL AND
STABLE SURFACE CONDITIONS.  THIS UNSTABLE AIR ALOFT WILL RESULT IN
ELEVATED THUNDERSTORM DEVELOPMENT WITH STRONG UPDRAFTS...AND
THESE THUNDERSTORMS WILL BE CAPABLE OF PRODUCING LARGE HAIL.

IN ADDITION TO THE HAIL THREAT...HEAVY RAIN IS AGAIN POSSIBLE FROM
EAST CENTRAL NEBRASKA SOUTH INTO SOUTHEAST NEBRASKA AND SOUTHWEST
IOWA.  SOME PLACES IN SOUTHEAST NEBRASKA PICKED UP OVER AN INCH OF
RAIN LAST NIGHT.  BESIDES SATURATING THE SOIL ACROSS THAT
AREA...LAST NIGHTS RAINFALL HAS PUSHED MANY STREAMS AND RIVERS TO
NEAR BANKFULL.  RAINFALL OF 1 TO 2 INCHES IS POSSIBLE OVER PARTS OF
THE AREA TONIGHT...AND THIS COULD CAUSE FLOODING OR FLASH FLOODING
OF LOW LYING AREAS.

CHERMOK