Severe Thunderstorm Warning 317, NWS Omaha, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
443 AM CDT SUN AUG 1 2004

.DISCUSSION...
IN THE SHORT TERM...LLJ IS PROVIDING SOME BOOST TO CLUSTER OF TSTMS
IN NORTHEAST NEB AS THEY MOVE SOUTHEAST...AND HAS EVEN ALLOWED SOME
BACK BUILDING IN THE SW IA COMPLEX.  EXPECT FAIRLY RAPID DISSIPATION
AFTER DAWN.

TODAY...MID LEVEL TEMPS CONTINUE TO WARM STRONGLY.  LOOKS LIKE MAX
TEMPS SHOULD BE AROUND 5F ABOVE YESTERDAY.  SFC WINDS STRONG ENOUGH
TO PREVENT SUPER HIGH DEW POINTS FROM TRAPPED EVAPOTRANSPIRATION
IN SHALLOW LAYER.  THIS WOULD PRODUCE HEAT INDICIES NEAR BUT
GENERALLY JUST BELOW 105.

BIG QUESTION FOR TONIGHT IS WHETHER AND WHERE CAP WILL BREAK.  AGREE
WITH SPC THAT BEST CHC WILL BE IN THE NORTHEAST CORNER NEB WHERE
THEY HAVE EXTENDED MDT RISK...BUT HAVE A LOT OF QUALMS ABOUT THE
AREA FARTHER SOUTH WHERE CAP LOOKS VERY STRONG.  EXTENDED 20 PCT
POPS FOR SOME CONSISTENCY...BUT WILL BE SURPRISED IF MUCH HAPPENS.
LLJ WILL KEEP OVERNIGHT TEMPS RATHER WARM.

MONDAY LOOKS LIKE THE HOTTEST DAY OF THE FORECAST.  MODELS HAVE NOT
BEEN VERY CONSISTENT ON LOCATION OF SFC LOW BY LATE AFTN.  BASED MAX
TEMPS ON 00Z RUNS WHICH HAD IT OVER E CNTRL NEB RATHER THAN S CNTRL
NEB LOCATION OF 06Z RUNS.  THIS WILL LIKELY BE IMPORTANT FOR HIGHS
AND HEAT INDICIES AS HOTTEST AIR WILL BE S AND SW OF LOW...WHILE
LIMITED MIXING AND VERY HIGH SFC DPTS SHOULD LIE ENE OF LOW.  THIS
WILL ALSO AFFECT PROSPECTS FOR TSTMS ALONG FRONTAL BOUNDARY AND
DRYLINE.

MODELS AGREE THAT THE FRONT WILL SINK INTO FAR SOUTH NEB ON
TUESDAY...AND KEEP BACKING TOWARD THE SOUTH AND SOUTHWEST.  RIDGE
ALOFT RETROGRESSES SOMEWHAT AS A SERIES OF SHORT WAVES COMES OVER
THE TOP AND DOWN THE EAST SIDE TOWARD THE MIDWEST.  WHAT THEY DO NOT
AGREE ON IS THE POSITION OF THE SFC LOW.  THUS IT REMAINS HARD TO
DETERMINE WHETHER OUR AREA WILL BE IN THE RING OF FIRE OR REMAINED
CAPPED.  CONTINUE TO THINK THAT THE GFS MOS IS OVERDONE WITH SFC
COOLING CONSIDERING THAT THE STRONG UPPER RIDGE REMAINS NEARBY.
ECMWF IS AGAIN HOT LOOKING BY NEXT WEEKEND.  MADE A FEW MINOR
DOWNWARD TEMP ADJUSTMENTS TO FIT BETTER WITH NEIGHBORS...BUT NO
WHOLESALE CHANGES.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.

&&

POLLACK

HAZARDOUS WEATHER OUTLOOK...CORRECTION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
621 PM CDT SAT JUL 31 2004

IAZ043-055-056-069-NEZ011-012-015>018-031>034-044-045-011100-
ANTELOPE-BURT-CEDAR-CUMING-DODGE-HARRISON IA-KNOX-MADISON-MONONA IA-
PIERCE-POTTAWATTAMIE IA-SHELBY IA-STANTON-THURSTON-WASHINGTON-WAYNE-
621 PM CDT SAT JUL 31 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PARTS OF NORTHEAST AND EAST
CENTRAL NEBRASKA AND SOUTHWEST IOWA.

.DAY ONE...TONIGHT AND SUNDAY

THERE IS A SLIGHT CHANCE FOR SEVERE THUNDERSTORMS TONIGHT.  THE
PRIMARY HAZARDS ARE LARGE HAIL AND DAMAGING WINDS.  THE MAIN AREA
OF ACTIVITY MAY OCCUR NORTH OF A TEKAMAH TO NORFOLK TO ALBION LINE.
WARM AIR AT MIDDLE LEVELS OF THE ATMOSPHERE IS EXPECTED TO PREVENT
THUNDERSTORM DEVELOPMENT SOUTH OF THIS LINE.  SEVERE STORMS MAY ALSO
DEVELOP OVER NORTHEAST NEBRASKA AND MOVE SOUTHEAST LATE AFTERNOON AND
EVENING ON SUNDAY.  AGAIN...LARGE HAIL AND DAMAGING WINDS WOULD BE
THE PRIMARY HAZARDS.

.DAYS TWO THROUGH SEVEN...SUNDAY NIGHT THROUGH SATURDAY

HEAT INDICES MAY BECOME 105 OR ABOVE BEGINNING MONDAY AFTERNOON. THIS
IS LIKELY TO BE THE BEGINNING OF A PROLONGED HOT PERIOD OVER THE
AREA.

.SPOTTER INFORMATION STATEMENT...

STORM SPOTTER ACTIVATION MAY BE NEEDED TONIGHT AND SUNDAY
AFTERNOON AND EVENING.

IAZ079-080-090-091-NEZ030-042-043-050>053-065>068-078-088>093-011100-
BOONE-BUTLER-CASS-COLFAX-DOUGLAS-FREMONT IA-GAGE-JEFFERSON-JOHNSON-
LANCASTER-MILLS IA-MONTGOMERY IA-NEMAHA-OTOE-PAGE IA-PAWNEE-PLATTE-
RICHARDSON-SALINE-SARPY-SAUNDERS-SEWARD-
621 PM CDT SAT JUL 31 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PARTS OF SOUTHEAST NEBRASKA AND
SOUTHWEST IOWA.

.DAY ONE...TONIGHT AND SUNDAY

THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS TONIGHT  INCREASING
WARM AIR ALOFT COULD INHIBIT THUNDERSTORM DEVELOPMENT ALTOGETHER.
SMALL HAIL AND GUSTY WINDS WOULD BE THE PRIMARY HAZARDS WITH ANY
STORMS THAT DEVELOP.

.DAYS TWO THROUGH SEVEN...SUNDAY NIGHT THROUGH SATURDAY

HEAT INDICES MAY BECOME 105 OR ABOVE BEGINNING MONDAY AFTERNOON. THIS
IS LIKELY TO BE THE BEGINNING OF A PROLONGED HOT PERIOD OVER THE
AREA.

.SPOTTER INFORMATION STATEMENT...

STORM SPOTTER ACTIVATION SHOULD NOT BE NEEDED TONIGHT OR SUNDAY.

SMITH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
205 AM CDT SUN AUG 1 2004

NEZ015-010730-
THURSTON-
205 AM CDT SUN AUG 1 2004

...SEVERE THUNDERSTORM WATCH NUMBER 677 HAS BEEN CANCELLED...

THE SEVERE THUNDERSTORM WATCH HAS BEEN CANCELLED FOR THURSTON COUNTY.

ZAPOTOCNY