Severe Thunderstorm Warning 49, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
316 AM CDT SAT MAY 22 1999

MAIN CHALLENGE WILL BE POPS TODAY AND THIS EVENING AS COLD FRONT
MOVES SE THROUGH FA.

KLNX 88D PRESENTLY SHOWING WDLY SCATTERED SHOWERS AND A FEW TSTMS
MOVING ESE THROUGH FA. ACTIVITY TO FURTHER DIMINISH WHILE MOVING E
INTO MORE STABLE AIR AND COUPLET OF LOW LEVEL CONVERGENCE AND UPPER
LEVEL DIVERGENCE MOVES E. 06Z SFC ANALYSIS SHOWED HIGH PRESSURE
CENTER OVER SERN NEB INTO NERN KS...WHILE SFC FRONT EXTENDED FROM NR
PHP TO CDR TO LOW CNTR N OF DEN. IR SAT IMAGERY SHOWS CLEARING W
ACROSS THE NEB PANHANDLE WITH FEWER MID AND HIGH CLOUDS.

00Z MODEL SOLUTIONS CLOSE WITH MINOR VARIATIONS IN TIMING OF
FEATURES. A BLEND OF GUIDANCES USED WITH SLOWER MOVEMENT OF FRONT
THROUGH FA FOR THIS AFTN.

UPPER LEVEL S/W WILL MOVE E THIS EVENING WITH SUFFICIENT
INSTABILITY DUE TO AFTN HEATING WITH FRONT AS FOCUS FOR WDLY SCT
TSTMS TO FORM WITH BEST ACTIVITY TO OCCUR IN THE EVENING AS 5H S/W
MOVES THROUGH. AFTN CAPES TO 2400 J/KG AND LIS OF -2 TO -4 TO
DECREASE TOWARD EVENING AS FRONT MOVES S WITH ELEVATED CONVECTION
POSSIBLE WITH PASSAGE OF FRONT IN THE W. BEST MOISTURE APPEARS TO
BE ACROSS THE NCNTRL WITH BETTER POPS AS LOW LEVEL MOISTURE POOLS
ALONG AND AHEAD OF FRONT WITH DWPTS INTO THE 50S.

BY MIDNIGHT DRIER AIR TO FILTER INTO THE W AS UPPER RIDGE SHARPENS
IN THE W...WHILE REX BLOCK KEEPS SLOW DRIFT OF 5H LOW TO THE E
THROUGH 72 HOURS. DRIER AIR FILTERS IN FOR THE REMAINDER OF THE
PERIOD WITH SUNNY CONDITIONS SUNDAY WITH TEMPERATURES NEAR
GUIDANCES WHICH ARE CLOSE.

FOR THE EXTENDED...MONDAY THROUGH WEDNESDAY MRF TAKES 5H CLOSED LOW
ON MORE NERN PATH AND WEAKENS ON WED AS IT MOVES ACROSS CO. HIGH
PRESSURE WILL CONTINUE TO DOMINATE AT THE SFC AND ALOFT THROUGH
TUESDAY EVENING. THEN AS BOUNDARY SETS UP ACROSS THE SRN PLAINS
UPSLOPE FLOW TO SPREAD LOW LEVEL MOISTURE BACK NWD WITH THE
POTENTIAL FOR LATE AFTN/EVENING CONVECTION IN THE W ON WED. NO
CHANGES MADE TO PRESENT EXTENDED PERIOD.

.LBF...NONE

KECK

NEZ004>010-022>029-035>038-056>059-069>071-222200-

SEVERE WEATHER OUTLOOK FOR WESTERN AND NORTH CENTRAL NEBRASKA
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1124 AM CDT SAT MAY 22 1999

...STORM SPOTTERS IN SOUTHWEST AND NORTH CENTRAL NEBRASKA SHOULD BE
ALERT FOR POSSIBLE ACTIVATION THIS AFTERNOON INTO THE EVENING...

THERE IS A CHANCE FOR SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING
OVER PORTIONS OF SOUTHWEST AND NORTH CENTAL NEBRASKA. THE GREATEST RISK
OF SEVERE WEATHER WILL BE SOUTHEAST OF A FROM VALENTINE TO ALLIANCE.
STRONG THUNDERSTORMS ARE ALSO POSSIBLE IN SHERIDAN COUNTY AND NORTHWEST
CHERRY COUNTY IN THE AFTERNOON...BUT STORMS WILL NOT LIKELY REACH
SEVERE LEVELS UNTIL THEY MOVE SOUTHEAST THIS AREA.

A COLD FRONT WILL MOVE SOUTHEAST THROUGH WESTERN AND NORTH CENTRAL
NEBRASKA THIS AFTERNOON AND EARLY EVENING. THUNDERSTORMS ARE EXPECTED
TO DEVELOP ALONG THE FRONT EARLY IN THE AFTERNOON IN NORTH CENTRAL
NEBRASKA. THE STORMS MAY BECOME SEVERE AS THEY MOVE INTO AN AREA OF
INCREASING INSTABILITY AIDED BY MORNING SUNSHINE AND ABUNDANT LOW LEVEL
MOISTURE.

THUNDERSTORMS WILL CONTINUE THROUGH LATE AFTERNOON AND EARLY EVENING
ALONG AND BEHIND THE COLD FRONT. THE THREAT FOR SEVERE STORMS WILL
DIMINISH IN THE EVENING FROM NORTHWEST TO SOUTHEAST ACROSS WESTERN
NEBRASKA AS DRIER AND MORE STABLE AIR MOVES INTO THE AREA.

SHEETS

NEZ004>010-022>029-035>038-056>059-069>071-222200-

SEVERE WEATHER OUTLOOK FOR WESTERN AND NORTH CENTRAL NEBRASKA
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1124 AM CDT SAT MAY 22 1999

...STORM SPOTTERS IN SOUTHWEST AND NORTH CENTRAL NEBRASKA SHOULD BE
ALERT FOR POSSIBLE ACTIVATION THIS AFTERNOON INTO THE EVENING...

THERE IS A CHANCE FOR SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING
OVER PORTIONS OF SOUTHWEST AND NORTH CENTAL NEBRASKA. THE GREATEST RISK
OF SEVERE WEATHER WILL BE SOUTHEAST OF A FROM VALENTINE TO ALLIANCE.
STRONG THUNDERSTORMS ARE ALSO POSSIBLE IN SHERIDAN COUNTY AND NORTHWEST
CHERRY COUNTY IN THE AFTERNOON...BUT STORMS WILL NOT LIKELY REACH
SEVERE LEVELS UNTIL THEY MOVE SOUTHEAST THIS AREA.

A COLD FRONT WILL MOVE SOUTHEAST THROUGH WESTERN AND NORTH CENTRAL
NEBRASKA THIS AFTERNOON AND EARLY EVENING. THUNDERSTORMS ARE EXPECTED
TO DEVELOP ALONG THE FRONT EARLY IN THE AFTERNOON IN NORTH CENTRAL
NEBRASKA. THE STORMS MAY BECOME SEVERE AS THEY MOVE INTO AN AREA OF
INCREASING INSTABILITY AIDED BY MORNING SUNSHINE AND ABUNDANT LOW LEVEL
MOISTURE.

THUNDERSTORMS WILL CONTINUE THROUGH LATE AFTERNOON AND EARLY EVENING
ALONG AND BEHIND THE COLD FRONT. THE THREAT FOR SEVERE STORMS WILL
DIMINISH IN THE EVENING FROM NORTHWEST TO SOUTHEAST ACROSS WESTERN
NEBRASKA AS DRIER AND MORE STABLE AIR MOVES INTO THE AREA.

SHEETS