Severe Thunderstorm Warning 11, NWS Omaha, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
305 PM CDT SUN MAY 7 2000

FORECAST CONCERNS RMN TSTM/RAIN CHCS AND TIMING THROUGH MONDAY.
ALTHO ETA LOOKD BEST WITH SFC LOW PSN AT 18Z...IT MAY BE TOO FAR S
WITH BEST PRES FALLS NOW IN SRN SD.  WL STILL LEAN TWD ETA BUT AVN
WL BE USED SOME FOR COMP.

SHORT TERM...CLDS AND WK E/SE SFC WNDS EARLIER HAD MADE SFC FNT
SOMEWHAT HARD TO ANLYZ...BUT WRMFNT ESTIMATED AT 20Z TO BE SETTING
UP NOW N OF NEBR...WITH ANOTHER WRMFNT FM SFC LOW NERN CO INTO
SCNTRL KS.  MID LVL CAPPING APPEARS STG ENOUGH TO SUPPRESS MOST OF
THE ACTIVITY ALNG AND N OF SRN WRMFNT...ALTHOUGH CAN'T RULE OUT
ISOLD SHRA LIKE WHAT DVLPD YDA.  HOWEVER...MAIN ACTION EXPECTED N OF
SFC LOW/FNT WHERE CONVECTION WAS ALREADY DVLPG FM CNTRL WY INTO SD
WITH NEW CONVECTION DVLPG OFF MTNS NR CYS.  TSTMS SHOULD SPREAD/DVLP
EWD AS A STG SHRTWV TROF NOW PUNCHING INTO WRN WY MOVES E/NE INTO
NRN HIGH PLAINS DRAGGING A CDFNT INTO WRN CWA TWD 06Z.  LOW CLDS
HAVE HELD BACK HEATING AND INSTABILITY A LTL...BUT THINNING/BREAKS
THROUGH 00Z SHOULD ALLOW FOR CONTD RECOVERY.  FOR OAX FCST AREA...
BEST TSTM CHCS CONT TO BE NERN ZONES WHERE MID LVL TEMPS/CAP
COOLER.  WL CONT POPS IN LIKELY CATEGORY THERE WITH MENTION OF SVR
WITH SPC TEST GRAPHICS INDICATING 0-6KM WIND SHEAR IN 45-55 KT
RANGE.  FTHR S POPS APPEAR LESS LIKELY...AND IF AVN MID LVL
TEMPS/CAP VERIFIES...FAR SERN ZONES COULD MISS PCPN TNGT.  WL CONT
WITH LOWER POPS SERN ZONES.  FNT PRBLY NOT THROUGH FAR SERN NEBR/FAR
SWRN IA COUNTIES TIL AFT 12Z MON.  WL ADJ FOR THIS.

WL CONT POPS ALL AREAS ON MONDAY...BUT MAINLY MORNING N...AS SWRLY
FLOW ALOFT WITH EMBEDDED SHORTWV COULD TRIGGER SHWRS IN POST FNTL
MOIST/ COOLER AIRMASS.  PREV FCST TEMPS LOOK OK FOR BOTH TNGT/MON.
FWC MAYBE A BIT TOO WRM S TOMORROW.

WITH WK OR NO FORCING MON NGT/TUE WL GO WITH PTCLDY SKIES WITH NO
MENTION OF PCPN ATTM{.  COULD BE ENOUGH CLDS ARND YET MON NGT TO GO A
DEG OR TWO ABV FWC AND IF RECENT ETA'S COOL BIAS HOLDS WITH PROGD
850 MB TEMPS...HIGHS TUE MAY ALSO BE FEW DEGREES ABV FWC.

.OMA...NONE.
CHERMOK

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-081200-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
810 PM CDT SUN MAY 7 2000

SPOTTER GROUPS ACROSS NORTHEAST NEBRASKA WILL PROBABLY BE NEEDED TO
MONITOR STORMS LATER THIS EVENING AND TONIGHT.  THERE IS A MODERATE
RISK OF SEVERE WEATHER MAINLY WEST OF A LINE FROM WAYNE TO COLUMBUS.
THERE IS A SLIGHT RISK OVER THE REMAINDER OF EASTERN NEBRASKA AND
SOUTHWEST IOWA.

WARM AND HUMID CONDITIONS ARE IN PLACE AT THE SURFACE.  THUNDERSTORMS
OVER WESTERN AND NORTH CENTRAL NEBRASKA ASSOCIATED WITH AN UPPER
LEVEL DISTURBANCE ARE EXPECTED TO CONTINUE MOVING EAST.  THIS WILL
HELP PUSH A COLD FRONT ACROSS MUCH OF THE AREA LATER TONIGHT.  THE
FRONT WILL BE A FOCAL POINT FOR ADDITIONAL STORM DEVELOPMENT.

THE COMBINATION OF INSTABILITY AND WIND SHEAR WILL BE FAVORABLE FOR
SUPERCELL THUNDERSTORMS.  THERE WILL BE TWO MAIN THREATS FROM THESE
STORMS...DAMAGING WINDS AND HAIL.

MILLER

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-081200-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
955 PM CDT SUN MAY 7 2000

STORM SPOTTER GROUPS WILL BE NEEDED ACROSS PARTS OF EASTERN NEBRASKA
AND SOUTHWEST IOWA.  A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR
FOR THE AREA MAINLY NORTHWEST OF A LINE FROM ONAWA IOWA TO DAVID
CITY NEBRASKA UNTIL 3 AM CDT.  THERE IS A CHANCE OF THUNDERSTORMS
OVER ALL OF THE AREA.

THUNDERSTORMS OVER CENTRAL NEBRASKA WILL CONTINUE TO MOVE EAST.  SOME
OF THESE STORMS HAVE A HISTORY OF PRODUCING DAMAGING WINDS AND HAIL.
BE ON THE LOOKOUT FOR THREATENING WEATHEiR CONDITIONS.

MILLER