Hail and Damaging Winds in Nebraska, April 22, 2001

SOUTH CENTRAL NEBRASKA/NORTH CENTRAL KANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
305 AM CDT SUN APR 22 2001

OBVIOUS CONCERNS FOR CONVECTION TODAY WITH SNOW CHANCES IN COLDER
AIR FOR TONIGHT.

SCATTERED CONVECTION ON GOING IN CWFA AS STRONG ISENTROPIC LIFT
OCCURS OVER SFC BOUNDARY SITUATED NEAR I 70.  NOT TOO WELL ORGANIZED
AT THIS TIME THOUGH BUT WILL NEED MORNING WORDING AS WARM AIR
ADVECTION EXPECTED TO CONTINUE IN EARNEST. BEST 850MB THETA E
ADVECTION FOCUSES ACROSS NW CWFA THIS MORNING AND THIS IS VERIFIED
BY INCREASED LIGHTNING ACTIVITY.  COULD BE SOME MARGINAL HAIL BUT
CERTAINLY AN INCREASE IN COVERAGE OVER NEXT FEW HOURS.

MEANWHILE UPPER LOW OVER NEW MEXICO WILL BE LIFTING OUT AS 100 PLUS
KNOT JET ROUNDS THE BASE DURING PREDAWN HOURS.  THE SURFACE FRONT
LIFTS NORTH THIS AFTERNOON IN RESPONSE TO FURTHER BACKING AND
INCREASING OF UPPER FLOW...CREATING UNIDIRECTIONAL FLOW.  SOUTHERLY
WINDS COULD INCREASE TO WIND ADVISORY CRITERIA IN SOUTHEAST CWFA BY
AFTERNOON.  IN ADDITION...A DRY PUNCH WILL MOVE ACROSS KANSAS.
THIS WILL SET THE STAGE FOR SQUALL LINE DEVELOPMENT AS PER SWODY1.
STRENGTH OF WIND FIELDS SUGGEST DAMAGING WINDS SHOULD BE COMMON AS
THIS LINE RACES ACROSS THE CWFA.  WILL HOLD OFF ON ADVISORY DUE TO
FORECAST CONVECTION AND DEAL WITH WINDS IN SEVERE WEATHER OUTLOOK.

ATTENTION THEN SHIFTS TO COLDER AIR MOVING IN TONIGHT.  MODEL TEMP
PROGS HAVE CONVERGED...SO WILL GO WITH THEIR SOLUTION.  THIS BRINGS
AT LEAST A MIX OF SNOW TO NORTHERN AND WESTERN AREAS
TONIGHT...ENDING IN NORTHEAST MONDAY MORNING.  ETA SNOW ACCUMULATOR
SHOWS ABOUT 2 INCHES BY MONDAY MORNING ACROSS THE NORTH.  WHILE IT
IS CONCEIVABLE THAT A PERIOD OF HEAVY SNOW COULD COOL THE BOUNDARY
LAYER DOWN ENOUGH TO MAKE SOME STICK ON GRASSY SURFACES...IT LOOKS
LIKE MOST OF THE HEAVIER PCPN MOVES OUT BEFORE BEST COLD AIR MOVES
IN.  THEREFORE WILL JUST GO WITH A POSSIBLE MIX.  BLYR TEMPERATURES
FIGURE TO STAY HIGH ENOUGH FOR ALL RAIN IN SOUTHEAST.

TEMP GRADIENT WILL BE A BIG CHALLENGE TODAY FOR ZONE WORDING. AT
LEAST ALL MODEL GUIDANCE IS IN FAIR AGREEMENT...SO WILL STAY IN THAT
REALM.  ON MONDAY...AM SKEPTICAL OF RAPID RECOVERY OF TEMPS OVER WET
GROUND SO WILL STAY ON LOW END OF GUIDANCE.  FREEZING TEMPS MONDAY
NIGHT MAY NOT BE AS WIDESPREAD AS CURRENTLY FORECAST AS IT APPEARS
THAT WARM ADVECTION BEGINS AND CLOUDS INCREASE AFTER MIDN8IGHT.  WILL
UP TEMPS A BIT THEN.

LITTLE CHANGES EXPECTED IN THE EXTENDED FORECAST.

.GID...NONE

DROZD

KSZ005>007-017>019-220845-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HASTINGS NE
300 AM CDT SUN APR 22 2001

SEVERE THUNDERSTORM WATCH #166 THAT WAS IN EFFECT
FOR...JEWELL...MITCHELL...ROOKS...PHILLIPS...OSBORNE AND SMITH
COUNTIES UNTIL 3 AM CDT HAS EXPIRED.

THE THREAT FOR SEVERE WEATHER HAS ENDED ACROSS NORTH CENTRAL KANSAS.
SCATTERED SHOWERS WITH A FEW THUNDERSTORMS THOUGH WILL CONTINUE
THROUGH THE REST OF THE EARLY MO0RNING HOURS OVER NORTH CENTRAL
KANSAS. NONE OF THESE STORMS ARE EXPECTED TO BECOME SEVERE.

DEE

KSZ005>007-017>019-NEZ039>041-046>049-060>064-072>077-082>087-221700-

SEVERE WEATHER OUTLOOK - SOUTH CENTRAL NEBRASKA/NORTH CENTRAL KANSAS
NATIONAL WEATHER SERVICE HASTINGS NE
502 AM CDT SUN APR 22 2001

...SPOTTER ACTIVATION WILL LIKELY BE NEEDED TODAY...

SEVERE THUNDERSTORMS ARE A GOOD BET TODAY AND INTO EARLY THIS
EVENING ACROSS PARTS OF SOUTH CENTRAL NEBRASKA AND NORTH CENTRAL
KANSAS.  LARGE HAIL WILL BE THE MAIN THREAT INTO EARLY AFTERNOON
WITH DAMAGING WINDS BECOMING INCREASINGLY LIKELY DURING THE AFTERNOON
HOURS.  A FEW TORNADOES WILL ALSO BE POSSIBLE.

A FRONTAL BOUNDARY NEAR INTERSTATE 70 WILL SLOWLY MOVE NORTH THIS
MORNING AS A WARM FRONT.  MOIST AIR OVERRIDING THE FRONT IN ADVANCE
OF ONE UPPER LEVEL WEATHER SYSTEM WILL CAUSE THUNDERSTORMS CAPABLE OF
PRODUCING LARGE HAIL.

LATER TODAY THE WARM FRONT WILL SURGE NORTHWARD AS THE MAIN AREA OF
LOW PRESSURE MOVES NORTHEAST ALONG IT.  IN ADDITION...A DRY LINE WILL
ADVANCE EAST ACROSS KANSAS AND SOUTHERN NEBRASKA.  A SQUALL LINE WILL
FORM WHERE THE WARM MOIST AIR MEETS THE DRY AIR FROM THE WEST.
DAMAGING STRAIGHT LINE WINDS OF 80 MPH WILL BE POSSIBLE THIS
AFTERNOON INTO EARLY EVENING AS THIS SQUALL LINE MOVES THROUGH.
FURTHERMORE...AN ISOLATED TORNADO ALONG THIS LINE CANNOT BE RULED
OUT.

THE THREAT FOR SEVERE WEATHER SHOULD END BY NIGHTFALL.

DROZD