Severe Thunderstorm Warning 95, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
245 PM CDT TUE JUN 2 1998

...FORECAST PROBLEM THIS EVENING IS TEMPERATURES AND THE EXTENT OF
PRECIPITATION TEMPERATURES...

AVN, ETA, AND NGM SOLUTIONS ARE SIMILAR IN THEIR HANDLING OF THE UPPER
LEVEL TROUGH IN THE WEST AND THE ASSOCIATED SHORT WAVES. THE ETA IS
MORE PROGRESSIVE THAN EITHER THE NGM OR AVN WITH LOW LEVEL FEATURES.
WITH THE DEEP TROUGH IN THE WEST, HAVE CHOSEN THE SLOWER SOLUTIONS,
I.E., A BLEND OF THE AVN AND THE NGM.

ISENTROPIC FORECASTS FROM THE NGM INDICATE THAT A FRONT ALOFT WILL STALL
IN NORTHERN KANSAS, WHERE IT WILL STAY THROUGH AT LEAST THURSDAY
MORNING. DURING THAT ENTIRE PERIOD, THE SYSTEM RELATIVE LIFT ON THE 310K
AND 304K THETA SURFACES (USING SYSTEM MOTION OF 280-300 AT 10KTS)
INDICATE ISENTROPIC UPGLIDE OVER A LARGE PART OF THE NORTH PLATTE
UPDATE AREA.

LOOKING AT THE CENTRAL AND EASTERN PARTS OF THE LBF AREA...
BY 06Z TONIGHT, MOST OF CENTRAL AND WESTERN NEBRASKA BEGINS PICKING UP
SIGNIFICANT ISENTROPIC LIFT ON THE 310K THETA SURFACE WITH MIXING
RATIOS OF 5-7G/KG AND CONDENSATION DEFICITS OF LESS THAN 50MB. THE NGM
HAS THAT CONDITION TAPERING OFF BY 18Z WEDNESDAY IN ALL BUT THE
PANHANDLE. SO, BELIEVE THAT PROBABILITY OF PRECIPITATION SHOULD BE
INCREASED TONIGHT AND WEDNESDAY MORNING OVER MOST OF THE NORTH PLATTE
UPDATE AREA, AND THROUGH WEDNESDAY AFTERNOON IN THE PANHANDLE.
ACTUALLY, I WOULD SUGGEST WORDING SUCH AS OCCASIONAL RAIN (OR SHOWERS)
FOR PRECIPITATION AFTER MIDNIGHT TONIGHT AND INTO WEDNESDAY MORNING
OVER MOST OF THE NORTH PLATTE CWA. WITH LIFTED INDICES OF LESS THAN
ZERO AT LEAST EARLY TONIGHT, SOME MENTION OF THUNDERTORMS IS
APPROPRIATE AS WELL. BEYOND THAT, AT LEAST SOME CHANCE OF PRECIPITATION
IS APPROPRIATE THROUGH FRIDAY.

THE OTHER NEWS IN THE FORECAST IS TEMPERATURE. THERE IS LITTLE DOUBT
THAT TEMPERATURES WILL BE MUCH COLDER THAN THEY HAVE BEEN. IN FACT,
NUMBERS APPROACHING NORMAL EARLY JUNE VALUES WILL PROBABLY NOT BE
EXPECTED UNTIL SUNDAY OR MONDAY (IF THEN).

SUGGESTED CCF

PRELIMINARY GUIDANCE FOR COORDINATION ONLY. OFFICIAL FORECAST IS
CONTAINED WITHIN THE PRODUCT OMAZFPNE.

LBF CC 048/062 047/058 043 49846
VTN CC 045/057 045/058 040 49846

OGA CC 049/061 048/058 044 49846
IML CC 051/062 049/058 045 49846
BBW CC 051/061 050/059 045 49634
ANW CC 048/058 047/058 042 49634
ONL CC 049/058 048/058 043 49634

SPRINGER