Severe Thunderstorm Warning 121, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
308 PM CDT THU JUL 10 1997

FORECAST PROBLEM...CHANCE OF THUNDERSTORMS AND TEMPERATURES

LATEST VISIBLE SATELLITE INDICATES CONVECTION OVER NORTHWEST
PANHANDLE WITH MOSTLY SUNNY OVER REST OF FA. CIRRUS OVER SOUTHWEST
NEBRASKA TAKING ON CONVECTIVE APPEARANCE. CURRENT ADAP SHOWING PLENTY
OF INSTABILITY OVER FA BUT CAP ALSO INDICATED. 18Z SURFACE MAP SHOWING
LOW PRESSURE OVER NORTHEAST WYOMING WITH COLD FRONT ACROSS NORTHERN
WYOMING. DRY LINE ACROSS EASTERN WYOMING/WESTERN NEBRASKA PANHANDLE.

UPPER RIDGE OVER THE PLAINS WILL SHIFT EAST INTO THE EASTERN THIRD
OF THE U.S. WHILE UPPER TROF MOVES INTO GREAT BASIN BY END OF PERIOD.
LEE TROUGH IS PROGGED TO MOVE INTO WESTERN NEBRASKA PANHANDLE THIS
EVENING WITH AREA OF LOW PRESSURE MOVING INTO THE CENTRAL AND NORTHERN
PLAINS FRIDAY AND SATURDAY.
TONIGHT...THUNDERSTORMS SHOULD BE CONFINED TO NORTHWEST PANHANDLE WITH
STEERING WINDS MOVING STORMS NORTHEAST INTO SOUTH DAKOTA.EASTWARD
PROGRESS SHOULD BE LIMITED WITH RIDGE TO THE EAST. RIDGE AND CAP
SHOULD SPARE REST OF FA. HOWEVER...PLENTY OF INSTABILITY SO
COULD GO ISOLATED OR WIDELY SCATTERED REST OF FA. SKY SHOULD BE
PARTLY CLOUDY THIS EVENING THEN D MOSTLY CLEAR ELSEWHERE WITH
AVERAGE RH 40 PERCENT. SOUTH WINDS 10-20 ACROSS FA PER BOUNDARY LAYER.

FRIDAY...PVA INDICATED TO MOVE INTO FA BY 12Z BUT CAP SHOULD LIMIT
CONVECTION UNTIL LATE AFTERNOON WHEN RIDGE MOVES FARTHER EAST. EXPECT
THUNDERSTORMS TO FIRE OVER PANHANDLE AND MOVE INTO NORTHCENTRAL LATE
AFTERNOON. MOSTLY SUNNY SKY ACROSS FA WITH 40-50 PERCENT AVERAGE RH
...SOME 60 PERCENT RH ALONG KANSAS BORDER BY NOON...BUT WILL KEEP
MOSTLY SUNNY ALL AREAS. SOUTH WINDS 10-20 ACROSS FA PER BOUNDARY
LAYER.

FRIDAY NIGHT...CONVECTION IN EVENING AHEAD OF TROUGH AND LOW IN THE
NEBRASKA PANHANDLE. BOUNDARY LAYER WINDS INDICATE SOUTH 5-10.

SATURDAY...SCATTERED THUNDERSTORMS VICINITY OF FRONT AND TROUGH
ACROSS FA IN AFTERNOON. SKY SHOULD BE PARTLY CLOUDY. WINDS AHEAD
OF FRONT SHOULD BE SOUTHWEST 5-15 SHIFTING TO THE NORTHWEST 10-20
BEHIND THE FRONT.
WILL GO WITH NGM GUIDANCE FOR LOWS AND A DEGREE OR TWO ABOVE GUIDANCE
FOR HIGHS.

LBF UB 065/090 064/090 060 123         ONL UB 066/091 066/090 060 113
IML UB 064/089 063/090 060 123         VTN UB 066/091 065/090 060 123
OGA UB 064/089 063/088 060 123

FS