Tornado Warning 54, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
137 PM CDT TUE AUG 17 1999

...FORECAST CHALLENGE WILL BE COVERAGE OF THUNDERSTORMS TONIGHT...

ETA AND NGM CONTINUE TO AGREE ON VORT CHANNEL TOPPING THE RIDGE BY THIS
EVENING AND MOVING ESE ACROSS SRN NE/NRN KS TONIGHT.  OTHER FACTORS
INCLUDE A SFC FRONT ACROSS NC KS PROGGED TO LIFT NORTHEAST INTO CENTRAL
NEBRASKA THIS EVENING.  DWPTS ABOVE 70 ALSO WILL POOL IN VCNTY OF THIS
FRONT TONIGHT. PREFER ETA WITH MOVEMENT OF VORT CHANNEL AND ASSOC 700
UVV OVER NGM...ALTHOUGH GENERAL AGREEMENT BETWEEN THE TWO INCREASES
CONFIDENCE OF AN MCS DEVELOPMENT TONIGHT.

250 MB DIV WILL SET UP NICELY FROM NW KS INTO EC NEBR BY 06Z WED...AS
RR QUAD OF JET SUPPORTS THIS.  850 CONV ALSO WILL SET UP IN ERN CO BY
00Z TONIGHT AND SPREAD EASTWARD ACROSS NRN KS/SRN NE OVERNIGHT.

A THETA E RIDGE DEVELOPS BY 00Z TONIGHT FROM WRN KS INTO WRN NE AND
ORIENTS INTSELF EAST-WEST ALONG THE NE/KS BORDER OVERNIGHT.  SOME HEAVY
RAINFALL POSSIBLE AS PWS TO NEAR 1.5 INCHES SOUTH AND EAST OF LBF. ALSO
EVENING WILL SUPPORT CHC OF SVR...MAINLY SOUTH OF I-80.  RATHER QUICK
MOVEMENT OF SYSTEM WILL LIMIT ANY SIGNIFICANT RAINFALL AMOUNTS HOWEVER.
WILL INCLUDE LIKELY POPS ACROSS THE SRN HALF OF CWA TONIGHT...AND LOWER
POPS TO THE NORTH.

UPPER RIDGE WILL BUILD WESTWARD THROUGH 48HRS.  ON WEDNESDAY GOOD
SUBSIDENCE BEHIND SYSTEM.  WINDS WILL ONCE AGAIN TURN TO THE NORTH AS
SFC HIGH MOVES SOUTHEAST.  APPROACH OF NRN STREAM SHORTWAVE WILL
PRODUCE AS SFC TROUGH FROM MONTANA INTO ERN WY BY THU MORNING. DRY FCST
WED AND THR.

FAN AND FWC TEMPERATURE GUIDANCE CLOSE WITH LOWER AND MID 80S WED...
WARMING SLIGHTLY INTO THE MID/UPPER 80S THR.

IN THE EXTENDED...CHC OF THUNDERSTORMS FRI.  DRY SAT AND SUN AS UPPER
RIDGE KEEPS MOST OF ENERGY WELL TO THE NORTH OF CWA. HIGHS IN THE MID
AND UPPER 80S IN NE COUNTIES WHILE AROUND 90 ELSEWHERE.  LOWS AROUND
60.

.LBF...NONE.

ROBERG

NEZ004>010-022>029-035>038-056>059-069>071-172045-

SEVERE WEATHER OUTLOOK FOR WESTERN AND NORTH CENTRAL NEBRASKA
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1100 AM CDT TUE AUG 17 1999

...STORM SPOTTERS MAY BE NEEDED LATE THIS AFTERNOON OR TONIGHT ACROSS
SOUTHWEST AND CENTRAL NEBRASKA...

CONDITIONS COULD BECOME FAVORABLE FOR SEVERE THUNDERSTORMS LATE THIS
AFTERNOON AND TONIGHT SOUTH OF A LINE FROM NEAR ALLIANCE...TO HYANNIS
...TO MULLEN...TO BREWSTER.

A STRONG UPPER LEVEL DISTURBANCE WILL MOVE OUT OF THE CENTRAL
ROCKIES THIS EVENING...AND LOW LEVEL MOISTURE WILL BE ON THE INCREASE
DURING THE AFTERNOON HOURS OVER THE OUTLOOK AREA. THE COMBINATION OF
THE UPPER LEVEL FEATURE AND INCREASING INSTABILITY WILL TRIGGER AN
ORGANIZED AREA OF THUNDERSTORMS...SOME OF WHICH MAY BECOME SEVERE.
THE MAIN SEVERE WEATHER THREAT WILL BE HAIL AND DAMAGING WINDS.

THUNDERSTORM DEVELOPMENT IS ALSO POSSIBLE ACROSS NORTH CENTRAL NEBRASKA
BY THIS EVENING...HOWEVER THESE STORMS ARE NOT EXPECTED TO BECOME
SEVERE.

GEB

NEZ004>010-022>029-035>038-056>059-069>071-172045-

SEVERE WEATHER OUTLOOK FOR WESTERN AND NORTH CENTRAL NEBRASKA
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1100 AM CDT TUE AUG 17 1999

...STORM SPOTTERS MAY BE NEEDED LATE THIS AFTERNOON OR TONIGHT ACROSS
SOUTHWEST AND CENTRAL NEBRASKA...

CONDITIONS COULD BECOME FAVORABLE FOR SEVERE THUNDERSTORMS LATE THIS
AFTERNOON AND TONIGHT SOUTH OF A LINE FROM NEAR ALLIANCE...TO HYANNIS
...TO MULLEN...TO BREWSTER.

A STRONG UPPER LEVEL DISTURBANCE WILL MOVE OUT OF THE CENTRAL
ROCKIES THIS EVENING...AND LOW LEVEL MOISTURE WILL BE ON THE INCREASE
DURING THE AFTERNOON HOURS OVER THE OUTLOOK AREA. THE COMBINATION OF
THE UPPER LEVEL FEATURE AND INCREASING INSTABILITY WILL TRIGGER AN
ORGANIZED AREA OF THUNDERSTORMS...SOME OF WHICH MAY BECOME SEVERE.
THE MAIN SEVERE WEATHER THREAT WILL BE HAIL AND DAMAGING WINDS.

THUNDERSTORM DEVELOPMENT IS ALSO POSSIBLE ACROSS NORTH CENTRAL NEBRASKA
BY THIS EVENING...HOWEVER THESE STORMS ARE NOT EXPECTED TO BECOME
SEVERE.

GEB