Hail in Nebraska, May 8, 2001

SOUTH CENTRAL NEBRASKA/NORTH CENTRAL KANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
217 PM CDT TUE MAY 8 2001

MAIN FOCUS FOR THIS PACKAGE IS THE CHANCE FOR CONVECTION AND RAIN
WEDNESDAY NIGHT THROUGH FRIDAY.

18Z SFC ANALYSIS SHOWS RELATIVELY WEAK PATTERN WITH TROF NEAR A VTN-
LHX LINE. 50+ DEW POINTS WERE POOLED IN A NARROW RIBBON EAST OF
THE TROF FROM SW KS INTO SC NEB. SATELLITE SHOWS CLUSTER OF HIGH
BASED CONVECTION SE NEB ACROSS NRN MO. H7 SHORT WAVE BARELY
DISCERNIBLE IN 12Z ANAL BUT INDENTIFIED BETTER ON PROFILERS APPEARS
TO BE THE PRIMARY CAUSE OF THE CONVECTION.

FORECAST THROUGH ABOUT NOON WEDNESDAY APPEARS STRAIGHT FORWARD WITH
LOW LEVEL WARM ADVECTION ON INCREASING SOUTHERLY FLOW AHEAD OF
APPROACHING FRONT/LOW. UPR FLOW REMAINS NORTHWEST WITH NO APPARENT
ADDITIONAL WAVES. SO DRY...WARMER AND WINDIER FORECAST LOOKS RIGHT.
MOS TEMPS LOOK REASONABLE IN GENERAL. MIXING FROM INCREASING WIND
OVERNIGHT SHOULD KEEP READINGS UP A BIT OVERNIGHT.

NEXT SIGNIFICANT UPPER WAVE WAS APPROACHING PACIFIC NORTHWEST WITH
12Z H5 ANALYSIS SHOWING 60M HGT FALLS. MODELS IN ACCORD TAKING THIS
WAVE ACROSS NRN STATES AND SRN CANADA...AND DAMPENING WRN STATES
RIDGE. ZONAL UPPER FLOW TO RESULT ACROSS CENTRAL PLAINS BY WED
AFTERNOON.

SURFACE REFLECTION OF THIS SYSTEM IS A FRONT FORECAST TO CROSS GID
CWA WED NIGHT. AVN IS SIGNIFICANTLY SLOWER WITH THIS SFC SYSTEM AT
36 HOURS AND ETA/NGM SOLUTIONS ON SIMILAR CASES HAVE BEEN SUPERIOR.
INCREASING INSTABILITY AND MOISTURE IN WARM SECTOR AHEAD OF FRONT
MAY LEAD TO WIDESPREAD AND SEVERE STORMS WEDNESDAY EVENING.  WILL
INCLUDE CHANCE FOR AFTERNOON CONVECTION INTO NORTHWEST GID CWA ABT
4PM WED AND SPREAD IT SOUTHEAST. POPS IN LIKELY CATEGORY ACROSS NEB
ZONES WED NIGHT...WITH 40 PCT IN KS.

ZONAL FLOW AND STALLING FRONT LEAD TO PERSISTENT CONVECTIVE EVENT
THURSDAY THROUGH FRIDAY. ISENTROPIC LIFT OVER FRONT...DYNAMICS IN
ZONAL UPPER FLOW AND CONTINUOUS FEED OF LOW LEVEL MOISTURE ALL LEAD
TOWARD A SIGNIFICANT RAIN EVENT THURSDAY NIGHT INTO FRIDAY.  HIGH
POPS APPEAR THE WAY TO GO.

MRF & AVN HOLD FRONT AND ZONAL FLOW IN PLACE FRIDAY WITH NEXT WAVE
TO TURN UPPER FLOW TO THE NW AND SFC HIGH TO DRIVE FRONT INTO
SRN KS/OK BY SATURDAY MORNING. AFTER BRIEF UPPER RIDGING AND FAIR
WEATHER SATURDAY...TSTMS RETURN TO FORECAST LATE SUN THROUGH TUES.
NEXT IN SERIES OF UPPER SYSTEMS AGAIN EXPECTED TO FLATTEN THE RIDGE
AND SEND LOW/FRONT ACROSS NEB & KS PRIMARILY SUNDAY AND MONDAY.
SHOWERS MAY LINGER INTO TUESDAY.

.GID...NONE.

SCHURR

KSZ005>007-017>019-NEZ039>041-046>049-060>064-072>077-082>087-082100-

SEVERE WEATHER OUTLOOK - SOUTH CENTRAL NEBRASKA/NORTH CENTRAL KANSAS
NATIONAL WEATHER SERVICE HASTINGS NE
1100 AM CDT TUE MAY 8 2001

...SPOTTER ACTIVATION WILL NOT BE REQUIRED THIS AFTERNOON OR TONIGHT
OVER SOUTH CENTRAL NEBRASKA AND NORTH CENTRAL KANSAS...

INCREASING INSTABILITY VIA DAYTIME HEATING TODAY...AND A PASSING
MID LEVEL DISTURBANCE MAY PRODUCE A FEW SHOWERS AND THUNDERSTORMS
THIS AFTERNOON...MAINLY EAST OF HIGHWAY 281. STORMS MAY PERSISTS INTO
THE EARLY EVENING HOURS OVER PARTS OF SOUTH CENTRAL NEBRASKA AND
NORTH CENTRAL KANSAS. WEAK WIND SHEAR AND INADEQUATE LOW LEVEL
MOISTURE SHOULD PREVENT STORMS FROM BECOMING SEVERE.

DEE