Hail and Damaging Winds in Nebraska, August 21, 2002

SOUTH CENTRAL NEBRASKA/NORTH CENTRAL KANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
205 PM CDT WED AUG 21 2002

...FORECAST CONCERN TO BE CHANCE OF RAIN NEXT COUPLE OF DAYS...

EXTENSIVE CLOUD DECK ACROSS MUCH OF THE CWA KEPT TEMPERATURES FROM
RISING EARLIER BUT WARMUP OCCURRING QUICKLY ACCORDING TO 18Z
OBSERVATIONS. LOW PRESSURE STILL SITTING OVER SOUTHERN SDAK BETWEEN
PIR AND SFD. TROUGH EXTENDS SOUTH TO NEAR BBW TO BETWEEN HLC AND
MCK AND CONTINUES SOUTH. DEWPOINTS DROP TO THE MID 50S TO THE WEST
OF THE TROUGH AND MID 40S AROUND CDR. MEANWHILE 70 DEWPOINT LINE HAS
A WESTERN EXTENT OF ODX TO JYR TO NEAR RSL WITH THE BEST MOISTURE
POOLING WHERE NE/IA/KS/MO MEET.

UPPER AIR ANALYSIS AT 12Z SHOWED NEXT SHORTWAVE APPROACHING FROM
WEST AND WAS JUST EAST OF DEN AND ABQ AT 700 MB. 17Z PROFILER
NETWORK AT THAT LEVEL PUT THE WAVE THROUGH MBW AND PLT ALTHOUGH
WINDS WERE LIGHT.  ALSO HAD A 700 WARM LAYER...13 TO 15C...IN PLACE
FROM DDC TO LBF.  PLENTY OF MOISTURE IN PLACE OVER CWA AT ALL
SIGNIFICANT LEVELS. 14C 850 DEWPOINT AREA ALSO EXTENDED FROM WEST
OF LBF TO DDC AND THEN NORTH AND EAST FROM THERE.

MESO ETA WANTING TO DROP SURFACE LOW TO NEAR BBW BY 18Z HASNT
MATERIALIZED AS NOTED ABOVE. SURFACE TROUGH HAS MOVED A LITTLE EAST
TODAY. IF IT WOULD BLAST THROUGH CWA IT WOULD END THE RAIN CHANCE
QUICKLY BUT DO NOT EXPECT THAT TO HAPPEN WITH SOUTHWEST FLOW ALOFT.
QUESTION THEN BECOMES LOCATION OF BOUNDARY NEXT 48 HOURS. WITH SOME
MOVEMENT CURRENTLY AND APPROACHING WAVE...THINK IT SHOULD CONTINUE
INTO THE CWA OVERNIGHT. EXPECT THUNDERSTORMS OF SCATTERED NATURE
EARLY AND THEN MAY BE A LITTLE MORE WIDESPREAD OVERNIGHT. BETTER
PARAMETERS SEEM TO BE EAST OF CWA AS FAR AS WIDESPREAD RAIN GOES.
PRECIPITABLE WATER LOOKS TO RANGE FROM 1.4 IN WESTERN CWA TO 2 IN
EASTERN NEB. WARM ADVECTION DID NOT LOOK THAT IMPRESSIVE OVER CWA
ACCORDING TO MESOETA TEMP ADVECTION AND ISENTROPIC CHARTS. ALSO WE
APPEAR TO BE IN RIGHT ENTRANCE REGION OF JET BUT IT IS NOT THAT
STRONG ACCORDING TO PROFILERS AND AGAIN WOULD HAVE MORE OF AN
AFFECT TO OUR NORTHEAST. TIME/HEIGHT SERIES OF OMEGA SHOWED VERY
WEAK LIFT OVERALL BEARING OUT WEAK LOW LEVEL WARM ADVECTION AND WEAK
UPPER FORCING.

OVERALL PLAN TO KEEP NIGHTTIME POPS GOING NEXT TWO OR THREE NIGHTS
WITH SURFACE BOUNDARY AND EMBEDDED SHORTWAVES RIDING THROUGH.
PLAN ON KEEPING EXTENDED DRY FOR NOW ALTHOUGH NEXT SURFACE SYSTEM
DUE IN TUES NIGHT OR WED MAY WARRANT POPS WITH LATER ISSUANCES.

.GID...NONE.

EWALD