Severe Thunderstorm Warning 3, NWS Omaha, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
335 PM CDT TUE APR 15 2003

MAIN FORECAST CHALLENGES ARE HANDLING THE PASSAGE OF TWO STRONG LOWS
DURING THE FORECAST PD.

IN THE SHORT TERM...SFC BASED INSTABILITY HAS BEEN HELD BACK BY
EXTENSIVE MID AND HIGH CLOUDS ABV A WARM DRY WEDGE OF AIR UP TO 600
MB IN MORNING SOUNDING...WITH A STEEP LAPSE RATE IN THE DRY LYR.
UPPER JET AND MID LEVEL CDFNT PUNCHING NORTHEAST FROM SOUTHERN
PLAINS SHOULD DESTABILIZE ENTIRE AIRMASS THIS EVE AND EARLY TNGT.
EXPECT WIDESPREAD PRECIP...BUT SEVERE POTENTIAL WILL BE SOMEWHAT
LIMITED BY LACK OF A GOOD FOCUSING BOUNDARY.

WEDNESDAY...ETA HAS TRENDED TO GFS SOLUTION WITH COLD CORE CLOSED
LOW PASSING TO OUR SOUTH ALOFT...BUT THERE IS STILL AN INVRTD TROF
AND DRY SLOT THAT MAY ALLOW SOME HEATING IN SOUTHEAST PORTIONS OF
THE FCST AREA IN THE FORENOON...WHICH COULD RESULT IN MORE TSTMS.
FURTHER INTO THE COLD AIR...EXPECT MORE WDSPRD RAIN WITH MAYBE SOME
EMBEDDED THUNDER.  AFT DISCUSSION WITH GID...DECIDED TO LEAVE OUT
MENTION OF WIND ADVSRY WED.  WE ARE IN A WEAKER GRADIENT THAN
FURTHER WEST...AND PROGGED 850 WINDS LOOK INSUFFICIENT TO SUPPORT AN
ADVSRY YET.  WE WILL LIKELY BE CLOSE TO CRITERIA IN OUR WESTERN
COUNTIES BY AFTN.

PRECIP SHOULD MOVE OUT OF THE AREA FAIRLY RAPIDLY WED NIGHT...BUT
EXPECT ENOUGH WIND AND STRATOCU TO PREVENT A FREEZE THU MORNING.

NEXT WEATHER MAKER WILL ARRIVE FROM THE SW DURING THE DAY FRIDAY.
PROSPECTS LOOK GOOD FOR MORE PRECIP BY FRIDAY AFTN...CONTINUING INTO
SAT AND PERHAPS SAT NIGHT.  THIS IS ANOTHER CLOSED LOW ALOFT WITH
SFC LOW PASSING THROUGH OR JUST SOUTH OF OUR FCST AREA...SO BEST
POPS WILL BE IN THE NORTH...BUT OVERALL PRECIP IS LIKELY.  RAISED
POPS CONSIDERABLY FOR THE PERIODS WITH BEST CHC OF RAIN...THEN DRIED
THE FCST OUT SUNDAY.  IF COLD AIR LINGERS ALOFT...THERE COULD STILL
BE A FEW SHOWERS LEFT DUE TO DAYTIME HEATING.   SUNDAY NIGHT AND
MONDAY ARE GETTING INTO THE RIDGE AXIS AND REALLY SHOULD BE DRY.
NEXT CHC OF PRECIP A POSSIBLE PRECURSOR SHORT WAVE EJECTING AHEAD
OF DIGGING WEST COAST TROF NEXT TUESDAY IN ENSEMBLES.  WORTH ONLY
A SLGT CHC AT THIS POINT.

TEMPS MORE SEASONABLE THAN RECENTLY.  DID NOT HAVE ANY BASIC
DISAGREEMENTS WITH HPC GUID IN LATER PDS.  DRY SLOT COULD PLAY HAVOC
WITH TEMPS TOMORROW...BUT IT WILL BE TOUGH TO PLACE THIS FEATURE
CORRECTLY IN SPACE OR TIME.

OMA...NONE.

POLLACK

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-161130-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
515 PM CDT TUE APR 15 2003

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

.DAY ONE...TONIGHT AND WEDNESDAY

THERE IS A CHANCE OF SEVERE THUNDERSTORMS ACROSS EASTERN
NEBRASKA AND SOUTHWEST IOWA TONIGHT AND WEDNESDAY.  LARGE HAIL
AND DAMAGING WINDS ARE THE PRIMARY HAZARDS...ALTHOUGH ISOLATED
TORNADOES ARE POSSIBLE THIS EVENING AND AGAIN WEDNESDAY
AFTERNOON.

AS A LARGE UPPER LEVEL SYSTEM MOVES OVER THE AREA LATE TONIGHT
AND WEDNESDAY...THE SEVERE WEATHER THREAT WILL SHIFT TO NEAR AND
EAST OF THE MISSOURI RIVER. IF ENOUGH AFTERNOON HEATING OCCURS
WEDNESDAY AFTERNOON...THE ENVIRONMENT COULD BECOME FAVORABLE FOR
MINI-SUPERCELLS AND POSSIBLE TORNADOES.

.DAYS TWO THROUGH SEVEN...WEDNESDAY NIGHT THROUGH MONDAY

THERE WILL BE ANOTHER CHANCE OF THUNDERSTORMS FROM FRIDAY INTO
SATURDAY AS ANOTHER STORM SYSTEM CROSSES THE CENTRAL PLAINS.
THE STORM TRACK IS STILL UNCERTAIN...AND SO IS THE AMOUNT AND
TIMING OF ANY SEVERE WEATHER.

.SPOTTER INFORMATION STATEMENT...

STORM SPOTTER ACTIVATION WILL LIKELY BE NEEDED...ESPECIALLY THIS
EVENING.

CHERMOK