Hail in Nebraska, April 2, 2001

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
321 PM CDT MON APR 2 2001

...POPS TONIGHT THEN CLOUDS AND TEMPS THROUGHOUT WILL BE A
CHALLENGE...

UPPER PATTERN CONSISTS OF FLAT RIDGING THROUGH THE CENTRAL U.S.
WITH TROFING ALONG BOTH COASTS. FAIRLY FAST JET AROUND 80 TO 110 KTS
CROSSING THE STATES. AT THE SURFACE...LOW PRESSURE IS CENTERED IN
THE VICINITY OF OK/TX PANHANDLES WITH LEE TROFING ALONG THE HIGH
PLAINS OF CO/WY/MT. DEEP MOISTURE FROM SOUTHERN PLAINS AS FAR NORTH
AS KS/NE BORDER AND NORTHEASTERN CO.

ALL INDICATIONS ARE CONVECTION IS LIKELY TO INITIATE IN VICINITY OF
NORTHEASTERN COLORADO WHERE MOISTURE IS ADVECTING RAPIDLY
NORTHWARD. LOW LEVEL CONVERGENCE...THETA E...AND CAPES ARE FAVORABLE
IN THIS AREA. ETA ALSO BRINGS A WEAK WAVE OVER THE AREA THIS
EVENING TO ENHANCE DEEP LAYER VERTICAL MOTIONS WHICH SHOULD AID IN
THE INITIATION. ENVIRONMENTAL WINDS AND STORM MOTION ANALYSES
SUPPORT DUE EASTWARD MOTION AT 25 TO 35 KTS WITH RIGHT MOVERS TO THE
SOUTHEAST. BEST POTENTIAL FOR SUPERCELL TYPE STORMS DOES APPEAR TO
BE SOUTH OF THE CWA WHERE BEST MOISTURE AND INSTABILITY IS.
REGARDLESS...STILL EXPECT SOME CONVECTION TO TRAVERSE THE
SOUTHWESTERN PORTIONS OF CWA THIS EVENING IN ASSOCIATION WITH
PASSING WAVE. THERE MAY EVEN BE SHOWERS AND ISOLATED STORMS OVER
NORTHERN PORTIONS OF CWA WHERE STRONGER UPGLIDE ASSOCIATED WITH
MORE SIGNIFICANT FEATURE LIFTING THROUGH SOUTH DAKOTA.
PRECIPITATION WITH THIS FEATURE WILL TEND TO BE MORE STABLE AND
LINGER TOWARD SUNRISE IN NORTH CENTRAL ZONES. OTHER CONCERN WILL BE
THE INFLUX OF LOW CLOUDS ON SOUTHEASTERLY FLOW. CLOUDS ARE ALREADY
AT THE KS/NE STATE LINE AND SHOULD OVERSPREAD THE CWA QUICKLY
TONIGHT.

SHOULD BE IN BETWEEN WAVES ON TUESDAY WITH UPPER RIDGE EXPECTED TO
AMPLIFY SLIGHTLY. SOUTHEASTERLY LOW LEVEL UPSLOPE FLOW WILL KEEP
LOW CLOUDS LOCKED IN OVER MUCH OF THE CWA. FAR SOUTHERN AND WESTERN
AREAS MAY EXPERIENCE AFTERNOON BREAKS. TEMPS WILL BE A TOUGH CALL
BUT SHOULD BE SAFE TO UNDERCUT GUIDANCE IN MOST AREAS.

ANOTHER WAVE FORECAST TO MOVE THROUGH WYOMING INTO SOUTH DAKOTA
TUESDAY NIGHT. H75 FRONTOGENESIS LOOKS TO BE WELL ALIGNED WITH
UPPER DIVERGENCE AND PV ADVECTION. SO ENHANCED VERTICAL MOTIONS
SUPPORT POTENTIAL FOR ANOTHER ROUND OF SHOWERS AND STORMS OVER
NORTHERN PART OF CWA. ALL AREAS WILL CLOUD OVER QUICKLY AGAIN AS
SOUTHEASTERLY FLOW IS EXPECTED TO PERSIST. CLOUDS WILL BEGIN TO
MINIMIZE DIURNAL RANGES AND LOWS IN THE 40S SEEM REASONABLE.

WEDNESDAY LOOKS SIMILAR TO TUESDAY...IN BETWEEN WAVES. SOUTHERLY LOW
LEVEL FLOW MAY BE MORE CONDUCIVE TO PARTIAL BREAKS IN AFTERNOON
OVERCAST FOR MOST OF THE CWA. MORE SUN AND WAA THROUGH H85 WOULD
SUPPORT WARMER MAXES AS PER GUIDANCE.

IN THE EXTENDED...AVN SOLUTION FOR THURSDAY LOOKS CONDUCIVE TO
CONVECTION OVER MUCH OF THE CWA WITH A LOW IN NORTHEASTERN COLORADO
...WARM FRONT OVER SOUTHERN PORTIONS OF THE CWA AND ANOTHER WAVE
EJECTING FROM WESTERN TROF. ALL MEDIUM RANGE GUIDANCE APPEARS TO HAVE
THIS SOLUTION WITH WIDE TEMP RANGES FROM NORTH TO SOUTH. SAME ON
FRIDAY AS THE ENTIRE WAVE EJECTS. DRY SATURDAY THROUGH MONDAY AS
ANOTHER UPPER RIDGE DtEVELOPS IN THE PLAINS.

.LBF...NONE.

DJB