Severe Thunderstorm Warning 57, NWS Omaha, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA NE
306 PM CDT TUE APR 10 2001

PRIMARY CONCERNS ARE SEVERE WEATHER POTENTIAL THROUGH
WED...RAINFALL...TEMPS...AND WINDS AS A MAJOR CYCLONE MOVES
NORTHEAST ACROSS THE AREA.

IN THE SHORT TERM...VERY MOIST AND UNSTABLE AIR FROM AMA N.E. TO TOP
AT 850 MB WAS UNDERESTIMATED BY MODELS.  ETA AGAIN SEEMS TO LOSE
SOME OF THE MOISTURE WHILE AVN REMAINS MOIST.  THIS AIR ADVECTING
NWD UNDER A SERIES OF RIPPLES IN THE UPPER JET HAS RESULTED IN
REPEAT TSTM DEVELOPMENT AND SLOWED TIEH NWD ADVANCE OF THE WARM
FRONT.  AS THIS PROCESS IS LIKELY TO CONTINUE WITH UPPER DIFL LIKELY
INCREASING AHEAD OF MAIN LOW OVERNIGHT...THE PROSPECTS FOR SVR WX
WILL CONTINUE.  ALSO THINK THE MODELS WILL REMAIN TOO FAST WITH THE
WARM FRONT.  FLOODING IS POSSIBLE...BUT STORMS SHOW FAST
MOVEMENT...SO WILL NOT HEADLINE FOR NOW.

ETA AND AVN ARE IN EXCELLENT AGREEMENT ON POSITIONS OF LOW AT SFC
AND ALOFT THRU 36 HRS...WITH ETA FASTER AFTER THAT.  DESPITE THESE
SIMILARITIES...THE AVN IS FASTER IN LIFTING THE DRY SLOT INTO OUR
AREA WEDNESDAY.  WILL TAKE A COMPROMISE SOLUTION.

WIND WILL ALSO BE A PROBLEM WED AND WED NIGHT AS THE STRONG LOW
MOVES THROUGH ERN NEB THEN MN.  GRADIENT DOES NOT LOOK QUITE AS
TIGHT AS LAST SYSTEM...SO FAR.  WINDS SHOULD DIE OUT GRADUALLY ON
THU AS WINDS ARE COUNTERACTED BY A DYING GRADIENT.

THU. NIGHT LOOKS COOL AND DRY PER GUIDANCE...WITH NO BIG CHANGES TO
EXTENDED.

.OMA...NONE.
POLLACK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
448 PM CDT TUE APR 10 2001

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

0356 PM    10 SE LINCOLN             NE   .88 INCH HAIL
04/10/01   LANCASTER                      REPORTED BY STORM
                                          SPOTTER.

0415 PM    12 N RED OAK              IA   1 INCH HAIL
04/10/01   POT2TAWATTAMIE                  REPORTED BY PUBLIC.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
523 PM CDT TUE APR 10 2001

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

0415 PM    12 E OAKLAND              IA   1.75 INCH HAIL
04/10/01   POTTAWATTAMIE                  REPORTED BY COOPERATIVE
                                          OBSERVER.

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-111000-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
530 PM CDT TUE APR 10 2001

STORM SPOTTER ACTIVATION WILL BE REQUIRED ACROSS PARTS OF EASTERN
NEBRASKA AND SOUTHWEST IOWA TONIGHT INTO WEDNESDAY MORNING.  LARGE
HAIL WILL BE THE MAIN SEVERE WEATHER THREAT TONIGHT...WITH A
TRANSITION TO A DAMAGING STRAIGHT LINE WIND EVENT LATE TONIGHT AND
WEDNESDAY MORNING.

LATE THIS AFTERNOON...A WARM FRONT WAS LOCATED OVER NORTHERN KANSAS
WITH A RAPIDLY DEEPENING SURFACE LOW OVER EASTERN COLORADO.  THIS
WARM FRONT WILL SLOWLY MOVE NORTH TONIGHT...WITH ELEVATED
THUNDERSTORM DEVELOPMENT LIKELY ACROSS MUCH OF EASTERN NEBRASKA AND
SOUTHWEST IOWA.  SINCE THE ATMOSPHERE IS MODERATELY UNSTABLE ABOVE A
SHALLOW LAYER OF COLD AIR NEAR THE GROUND...NORTH OF THE WARM
FRONT...LARGE HAIL WILL BE THE MAIN SEVERE WEATHER THREAT.
LOCATIONS ALONG AND SOUTH OF A DAVID CITY TO HARLAN IOWA LINE WILL
HAVE THE GREATEST THREAT OF SEVERE WEATHER THIS EVENING.

OVERNIGHT INTO WEDNESDAY MORNING...A STRONG SURFACE LOW WILL MOVE
RAPIDLY NORTHEAST ALONG THE WARM FRONT ACROSS KANSAS INTO EASTERN
NEBRASKA.  A LINE OF POTENTIALLY SEVERE THUNDERSTORMS IS EXPECTED TO
ACCOMPANY THIS SURFACE LOW AND TRAILING COLD FRONT.  DUE TO THE
EXPECTED RAPID MOVEMENT OF THESE STORMS...DAMAGING STRAIGHT LINE
WINDS WILL BE THE MAIN SEVERE WEATHER THREAT.  LOCATIONS ALONG AND
SOUTH OF AN ALBION TO ONAWA IOWA LINE WILL BE THE MOST LIKELY
LOCATIONS TO BE AFFECTED BY THESE THUNDERSTORMS.

MEAD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
753 PM CDT TUE APR 10 2001

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

1145 AM    OMAHA                     NE   .75 INCH HAIL
04/10/01   DOUGLAS                        HAIL COVERED THE GROUND
                                          AT 156TH AND F.
                                          REPORTED BY PUBLIC.

1155 AM    LA VISTA                  NE   .75 INCH HAIL
04/10/01   SARPY                          84TH AND BRENTWOOD.
                                          REPORTED BY PUBLIC.

1200 PM    COUNCIL BLUFFS            IA   1.5 INCH HAIL
04/10/01   POTTAWATTAMIE                  REPORTED BY PUBLIC.