Severe Thunderstorm Warning 131, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
254 AM CDT TUE JUL 22 1997

...FORECAST PROBLEM WILL BE THUNDERSTORM CHANCES...

MODELS SIMILAR WITH BROAD 500 RIDGE ACROSS MOST OF UNITED STATES WITH
WEAK FLOW EXCEPT OVER EXTREME NORTHERN U.S. WITH RIDGE RUNNERS OVER
DAKOTAS. SHORTWAVE OVER BAHA CALIFORNIA THAT HEADS NORTH BY 48 HOURS.
BASICALLY...NORTH PLATTE CWA DOES NOT GET ANY EFFECTS FROM ANY
SHORTWAVES AS SYSTEMS GO NORTH OR STAY WEST OF CWA. ONLY WEATHER MAKER
AS RIDGE RUNNERS CONTINUE TO PASS WELL NORTH OF CWA INTO THE DAKOTAS
AND MN.

KLNX RADAR SHOWING ISOLATED THUNDERSTORM SOUTHWEST VTN AND WATER VAPOR
IMAGERY SHOWING MONSOONAL MOISTURE HEADED EAST TOWARD CWA. WITH DARK
AREA ALSO NEAR CWA IN WATER VAPOR...WHEN MONSOON MOISTURE HIT DARK
AREA...ISOLATED SUPERCELL BLEW UP NORTH OF OGA LAST EVENING. FEEL WITH
MONSOONAL MOISTURE NEAR LBF AND FACT THAT THUNDERSTORM IS GOING BY
VTN...FEEL POPS CANNOT BE RULED OUT TODAY ACROSS LBF CWA EVEN WITH LACK
OF SHORTWAVES. WASHED OUT SFC FRONT NEAR AREA AS HARD TO FIND IN 06Z
ANALYSIS BUT THING FRONT IS BETWEEN BFF AND SNY AND JUST NORTH OF LBF.
THIS FRONT SHOULD PROVIDE A FOCUSING MECHANISM AND THERE SHOULD BE A
FEW OUTFLOW BOUNDARIES AROUND ALSO HELP FOCUS THUNDERSTORMS. AIRMASS
ALSO UNSTABLE AND AGREE WITH SPC DISCUSSION. CAPE VALUES ALSO PROGGED
TO BE IN 2000-3000 J/KG RANGE WITH 850 THTE RIDGE OVER CWA TODAY AND
700 THTE RIDGE OVER WESTERN NEBRASKA. THUNDERSTORMS WILL GET HARDER TO
FORM AFTER TONIGHT AS 700 TEMPS WARM AND CAP GETS STRONGER. WILL GO
CLOSE TO FWC FOR HIGHS AS CANNOT ARGUE WITH FWC VALUES SINCE I GET
CLOSE TO THESE USING MY 850 MIXING DOWN TO SFC METHOD.

GOING FORECAST LOOKS GOOD AND HAVE NO RECOMMENDATIONS.

CCF
LBF BB 089/064 092/066 093 702211  ANW BB 089/065 092/068 093 702222
OGA BB 090/064 093/066 093 702222  ONL BB 087/067 091/070 092 702222
IML BB 091/065 094/067 094 702222  BBW BB 088/064 091/066 092 702211
VTN BB 091/065 094/067 095 702222

MICHELS

NEZ004>010-022>029-035>038-056>059-069>071-231200-

SEVERE WEATHER OUTLOOK FOR WESTERN AND NORTH CENTRAL NEBRASKA
NATIONAL WEATHER SERVICE NORTH PLATTE NE
713 AM CDT TUE JUL 22 1997

THIS OUTLOOK PERTAINS TO THE FOLLOWING NEBRASKA COUNTIES...

ARTHUR     BLAINE     BOYD       BROWN      CHASE      CHERRY
CUSTER     DEUEL      FRONTIER   GARDEN     GARFIELD   GRANT
HAYES      HOLT       HOOKER     KEITH      KEYA PAHA  LINCOLN
LOGAN      LOUP       MCPHERSON  PERKINS    ROCK       SHERIDAN
THOMAS     WHEELER

...STORM SPOTTER ACTIVATION MAY BE NEEDED OVER NORTH CENTRAL AND
WESTERN NEBRASKA THIS AFTERNOON AND TONIGHT...

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE ENTIRE OUTLOOK
AREA THIS AFTERNOON INTO TONIGHT.

A SLOWLY MOVING WARMFRONT WILL MOVE ACROSS THE OUTLOOK AREA TODAY AND
WILL HELP TO PROVIDE A FOCUS FOR THUNDERSTORM DEVELOPMENT. WARM AIR
AT THE MID LEVELS THOUGH WILL PREVENT WIDESPREAD THUNDERSTORM
ACTIVITY...BUT ANY THUNDERSTORMS THAT DO FORM DUE TO STRONG SURFACE
HEATING AND ABUNDANT LOW LEVEL MOISTURE COULD BECOME SEVERE. THE
PRIMARY SEVERE WEATHER THREAT WOULD BE LARGE HAIL AND DAMAGING WIND.

MICHELS

NEZ004>010-022>029-035>038-056>059-069>071-241200-

SEVERE WEATHER OUTLOOK FOR WESTERN AND NORTH CENTRAL NEBRASKA
NATIONAL WEATHER SERVICE NORTH PLATTE NE
721 AM CDT TUE JUL 22 1997

THIS OUTLOOK PERTAINS TO THE FOLLOWING NEBRASKA COUNTIES...

ARTHUR     BLAINE     BOYD       BROWN      CHASE      CHERRY
CUSTER     DEUEL      FRONTIER   GARDEN     GARFIELD   GRANT
HAYES      HOLT       HOOKER     KEITH      KEYA PAHA  LINCOLN
LOGAN      LOUP       MCPHERSON  PERKINS    ROCK       SHERIDAN
THOMAS     WHEELER

...STORM SPOTTER ACTIVATION MAY BE NEEDED LATE THIS AFTERNOON INTO
TONIGHT ACROSS NORTH CENTRAL NEBRASKA...

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BY LATE AFTERNOON EAST
OF A LINE FROM BROKEN BOW TO MERRIMAN. SCATTERED THUNDERSTORMS ARE
POSSIBLE ACROSS THE REMAINDER OF THE AREA BUT ARE NOT EXPECTED TO REACH
SEVERE LEVELS.

WARM AIR AT THE MID LEVELS OF THE ATMOSPHERE WILL TEND TO INHIBIT
THUNDERSTORM DEVELOPMENT WEST OF THE SLIGHT RISK AREA. A TROUGH OF LOW
PRESSURE THOUGH ACROSS THE EASTERN PANHANDLE WILL TEND TO FOCUS
THUNDERSTORM DEVELOPMENT OVER THE WESTERN OUTLOOK AREA...BUT THE WARM
MID LEVELS WILL INHIBIT STRONG THUNDERSTORM DEVELOPMENT. IN THE SLIGHT
RISK AREA...SLIGHTLY COOLER AIR AT THE MID LEVELS COMBINED WITH STRONG
SURFACE HEATING WILL HELP FOR SCATTERED THUNDERSTORMS AND SOME OF THESE
COULD BE SEVERE. THE PRIMARY THREAT WOULD BE LARGE HAIL AND HIGH WINDS.

MICHELS