Severe Thunderstorm Warning 246, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
209 PM CDT FRI AUG 25 2000

...CHALLENGE TO BE TEMPS AND SMALL POPS BEGINNING SATURDAY AFTERNOON AND
CONTINUING INTO SUNDAY...

18Z SFC ANALYSIS SHOWS A SFC LOW NEAR HON WITH A FRONT DRAPED SW
INTO SW SD JUST TO THE N OF NEBR. STONGEST HEATING IN CW IN NE CWA
WHERE ONL UP TO 97. WINDS REMAIN LIGHT AND VRB IN SW AWAITING SFC
TROUGH PASSAGE.

ALL MODELS APPEAR TO HAVE INITIALIZED WELL AT 12Z. WATER VAPOR
IMAGERY SHOWS A DISTINCT SHORTWAVE LOCATED OVER NRN MT AND A TUT LOW
MIGRATING NORTHWARD ALONG THE NM/AZ BORDER. SUBTROPICAL MOISTURE
PLUME ROTATING AROUND THE RIDGE ACROSS NRN CO...SRN WY...INTO NEBR
AND ADJACENT STATES. MODELS DRAW VOT MAX NEAR THE NM/AZ BORDER
NORTHWARD ACROSS CO AND INTO NEBR BY 36 HRS. ETA SHOWING CHANNELIZED
VORTICITY UNDER THE SUBTROPICAL MOISTURE PLUME WHEREAS THE AVN AND
NGM DO NOT. PREFER THE ETA MODEL THIS RUN.

TONIGHT...SFC FRONT WILL PUSH SE OF CWA BY 06Z. EVENING TSRA WILL BE
INCLUDED FOR SRN AND ERN CWA. STRONG SUBSIDENCE AND CLEARING BEHIND
THE FRONT. ONLY PART OF SW WILL REMAIN PARTLY CLOUDY DUE TO SOME MID
AND HIGH CLOUDINESS. ONLY CONCERN WOULD BE STATUS AND PATCHY FOG
PUSHING INTO THE NE CWA LATE TONIGHT.

SATURDAY...SUNNY NORTHEAST AND MOSTLY SUNNY SW WHERE SOME MID HIGH
CLOUDS WILL INCREASE. DPVA NOTED INTO THE ERN PNAHDLE AND SW DURING
THE AFTERNOON. SFC FRONT WILL STALL OUT IN NRN KS AND LIFT NORTH IN
NW KS AND NE CO. WILL CONTINUE SMALL POPS FOR LATE AFTERNOON
THUNDERSTORMS IN ERN PNHDL AND SW TO THE NORTH OF THIS FRONT. DESPITE E
AND SE WINDS TEMPS COOL VERY LITTLE. HIGHS BACK INTO THE UPPER 90S IN
THE LBF BBW AREAS. MID 90S VTN AND OGA...LOWER 90S ERN PNHDL.

SATURDAY NIGHT...LOW PRESSURE ONCE AGAIN DEVELOPS IN MT AND
WY...MOVING EAST INTO WRN DAKOTAS AND WRN NEBR BY 12Z SUN. SMALL
POPS NEEDED FROM VTN TO LBF AND WEST AS SRN END OF 850 JET REACHES
INTO WRN NEBR OVERNIGHT. MOISTURE AND UPPER SUPPORT LACKING IN ERN CWA.

SUNDAY...SRLY WINDS AS LOW PRESSURE MOVES EASTWARN INTO CENTRAL SD
AND CENTRAL NEBR. BEST CHC OF TSRA SHIFT INTO ERN CWA AS VORT MAX
KICKS EAST AND BETTER MOISTURE ESTABLISHED. RIGHT ENTRANCE REGION OF
90+ KT JET TO THE NORTH SHOULD SUPPLY GOOD UPPER DIVERGENCE TO
EASTERN CWA BY AFTERNOON. 850 WINDS ALSO REMAIN AOA 20KTS. 30 POPS
ANW...ONL AND BUB. 20 POPS FOR MORNING SHOWERS IN THE SOUTH AND WEST.
TEMPS AROUND 90 NE...MID 90S SW WITH MORE SUN AND S TO SW WINDS.
90-95 NW.

EXTENDED...COLD FRONT WILL APPROACH NW CWA LATE SUNDAY NIGHT. A
SLIGHT COOL DOWN MODAY W/HIGHS IN THE MID 80S TO AROUND 90 AND A CHC
OF TSRA WITH FRONTAL PASSAGE. CHC INTO TUE...THEN DRY WED. HIGHS
TUES AND WED IN THE 80S. LOWS IN THE 50S.

.LBF...NONE

ROBERG

NEZ004>010-022>029-035>038-056>059-069>071-252045-

SEVERE WEATHER OUTLOOK FOR WESTERN AND NORTH CENTRAL NEBRASKA
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1115 AM CDT FRI AUG 25 2000

...STORM SPOTTER ACTIVATION IS NOT ANTICIPATED THIS AFTERNOON OR
TONIGHT...

A WEAK COLD FRONT WILL MOVE SOUTHEAST THROUGH WESTERN AND NORTH
CENTRAL NEBRASKA THIS AFTERNOON INTO THIS EVENING.  RAPIDLY RISING
TEMPERATURES IN ADVANCE OF THE FRONT...AND MARGINAL MOISTURE IN THE
LOWER ATMOSPHERE...WILL RESULT IN A MODERATELY UNSTABLE AIRMASS OVER
MUCH OF THE OUTLOOK AREA INTO EARLY TONIGHT.

WIDELY SCATTERED THUNDERSTORMS WILL DEVELOP IN THE VICINITY OF THE
FRONT DURING THE AFTERNOON...AND THEN PROGRESS EAST AND SOUTH AT
AROUND 30 MPH AS THE FRONT MOVES THROUGH THE AREA.

BECAUSE OF LIMITED MOISTURE...SEVERE WEATHER IS NOT EXPECTED FROM
ANY OF THE STORMS WHICH DEVELOP.  HOWEVER...LOCALLY GUSTY WINDS TO
NEAR 50 MPH...AND DRY LIGHTNING WHICH MAY RESULT IN ISOLATED PRAIRIE
FIRES IS POSSIBLE NEAR SOME OF THE STRONGER STORMS.

THE THREAT OF THUNDERSTORM ACTIVITY IS EXPECTED TO END OVER
NORTHWEST NEBRASKA BY SUNSET...AND END OVER THE REST OF WESTERN AND
NORTH CENTERAL NEBRASKA BY MID EVENING AS THE FRONT CONTINUES
SOUTHEAST AND MOVES OUT OF THE AREA.

WERT