Severe Thunderstorm Warning 203, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
120 PM CDT SAT AUG 24 2002

CLOUDS HAVE DISSIPATED OVER ALL BU THE SOUTHEAST PART OF THE
FORECAST AREA. WILL UPDATE THE FORECAST TO REFLECT FEWER CLOUDS AND
WARMER TEMPERATURES. THIS WILL ALSO AFFECT CONVECTION THIS EVENING,
BUT THAT WILL BE COVERED BY THE NEW FORECAST CYCLE.

SPRINGER

AREA FORECAST DISCUSSION
255 AM CDT SAT AUG 24 2002

...FORECAST CHALLENGE WILL BE THUNDERSTORM CHANCES THROUGH THE
WEEKEND AND TEMPS THROUGH THE FORECAST PERIOD...

U/A ANALYSIS AND SAT IMAGERY SHOWING H5 LOW SPINNING OVER EASTERN
OREGON...LEAVING HIGH PLAINS WITH H5 RIDGE OVER SOUTHERN PORTION OF
DESERT SW. WEAK WAVES IN FLOW WILL CONTINUE TO MOVE TOWARD CWA
KEEPING THE THREAT OF TSRA IN FORECAST THROUGH WEEKEND. LATEST WAVE
AT 04Z MOVING INTO EASTERN CO...KICKING OFF CONVECTION OVER EASTERN
CO AND MAY LEAD TO DEVELOPMENT ACROSS CWA THIS MORNING. MCS OVER
NORTH CENTRAL CWA MOVING SE AS PER CORFIDI VECTORS. LEFT EXIT REGION
OF SUBTROPICAL JET ALSO AIDING IN ASCENT WHICH IS NOSED INTO THE
ROCKIES OF COLORADO. SFC MAP NOT SO WELL DEFINED WITH CONVECTION
ONGOING...BUT MAIN FEATUES SEEM TO BE SFC LOW OF SE COLORADO WITH
FRONT EXTENDING EASTWARD NEAR THE KS/OK BORDER. INVERTED SFC TROF
ALONG LEE OF ROCKIES INTO SE WYOMING...WITH NUMEROUS OUTFLOW
BOUNDARIES APPARENT ON 8BIT REF...ALSO COULD BE FOCUS POINTS FOR
CONVECTION TODAY.

WILL PROBABLY BE DEALING WITH CONVECTION THROUGHOUT THE CWA THROUGH
THE NEXT 48 HOURS. AS H25 JET AXIS SLOWLY MIGRATES NORTH...RIDGE IN
SW IS ALLOWED TO EXPAND NORTHWARD PUTTING CWA IN NW FLOW AND
ALLOWING ENERGY TO CONTINUE TO ROTATE AROUND RIDGE ONTO THE PLAINS.
LOOKS LIKE BEST CHANCES WILL BE IN THE WEST AND SW THROUGH
TONIGHT...SHIFTING TO NORTHERN AND EASTERN SECTIONS SUNDAY INTO
MONDAY.

TODAY...WAVE MOVING OUT THE HIGH PLAINS THIS MORNING AND FAVORED JET
REGION SHOULD HELP CONVECTION CONTINUE ACROSS WESTERN CWA THIS
MORNING...SHIFTING INTO EASTERN SECTIONS THIS AFTERNOON. NO
SIGNIFICANT SFC BOUNDARY TO SPEAK OF BUT THERE WILL BE OUTFLOW
BOUNDARIES TO CONTEND WITH. LOW LEVEL EAST/SOUTHEAST FLOW WILL KEEP
THETA-E RIDGE OVER WESTERN PORTIONS OF CWA...ALSO AIDING IN GOOD
VEERING PROFILES/WAA. TEMPS TODAY WILL BE TRICKY WITH CONVECTION AND
ASSOC CLOUDINESS. WILL START OUT WITH NEAR 80/80 TO 85 DEGREE RANGE
MOST PLACES WHICH IS NEAR GUIDANCE NUMBERS AND PREVIOUS FORECAST.

TONIGHT BEST CHANCES SEEM TO BE ASSOC WITH UPSLOPE FLOW INTO HIGH
PLAINS ALONG WITH THE THETA-E AXIS AND AREA OF STRONGEST 0-6KM
SHEAR. STORMS SHOULD FIRE ACROSS EASTERN CO AND WY AND WITH WESTERLY
FLOW ALOFT/CORFIDI VECTORS WILL ACCOUNT FOR A FEW STORMS MAKING IT
INTO WESTERN CWA THORUGH THE EVENING HOURS. SHOULD DIE OUT AFTER
SUNSET AS MODELS NOT INDICATING A STRONG LOW LVL JET AND LACK OF SFC
BOUNDARY.

SUNDAY WILL COOL TEMPS SLIGHTLY AS MODELS NOT REALLY SHOWING
CYCLOGENESIS ACROSS SOUTH DAKOTA...BUT RATHER JUST A LEE SIDE
TROF/DRY LINE. THIS FEATURE WILL MOVE EASTWARD OVER CWA LATE SUNDAY
PROVIDING FOCUS FOR TSRA LATE SUNDAY AFTERNOON INTO THE OVERNIGHT
HOURS. STRONGER ENERGY ASSOC WITH UPPER LOW OVER NORTHERN
PLAINS...WILL HELP PUSH TROF EASTWARD THROUGH CWA SUNDAY NITE. LIFT
FROM SHORTWAVE...CONVERGENCE ALONG TROF AND LEFT EXIT QUAD OF UPPER
JET WILL KEEP SLGHT POPS SUNDAY NITE.

WARM-UP MONDAY INTO TUESDAY AS WEST COAST TROUGH DIGS AND RIDGE
BUILDS OVER PLAINS...HOWEVER MODELS DIFFERING ON STRENGTH OF BOTH OF
THESE FEATURES WITH AVN STRONGER ON BOTH ACCOUNTS. AS A RESULT WILL
NOT MAKE ANY SIGNIFICANT CHANGES TO PREVIOUS FORECAST THROUGH THE
EXTENDED. WILL KEEP SLIGHT CHANCES OF TSRA BOTH MONDAY/TUESDAY
AFTERNOON AND EVENING.

.LBF...NONE.

DP

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE, NE
1026 AM CDT SAT AUG 24 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0850 PM    4 ENE GORDON              NE   1.00 INCH HAIL
08/23/02   SHERIDAN

TRM

NEZ004>010-022>029-035>038-056>059-069>071-094-242045-

HAZARDOUS WEATHER OUTLOOK FOR WESTERN AND NORTH CENTRAL NEBRASKA
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1110 AM CDT SAT AUG 24 2002

...STORM SPOTTER ACTIVATION MAY BE NEEDED TODAY AND TONIGHT ACROSS
PORTIONS OF WESTERN NEBRASKA...

CLEARING SKIES OVER PORTIONS OF THE NEBRASKA PANHANDLE AND SOUTHWEST
NEBRASKA WILL ENABLE AN ALREADY UNSTABLE ATMOSPHERE TO DESTABILIZE
EVEN FURTHER THIS AFTERNOON.  ABUNDANT MOISTURE REMAINS IN PLACE OVER
THE OUTLOOK AREA.  A SERIES OF UPPER LEVEL DISTURBANCES WILL CONTINUE
TO MOVE ACROSS AREA THIS AFTERNOON AND TONIGHT HELPING TO IGNITE
ANOTHER ROUND OF THUNDERSTORMS.

THE OUTLOOK AREA IS TO THE WEST OF A LINE FROM MERRIMAN...IN
NORTHWEST CHERRY COUNTY...TO NORTH PLATTE. THE PRIMARY THREAT WITH
THUNDERSTORMS THAT DO DEVELOP WILL BE DAMAGING WINDS AND LARGE HAIL.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE, NE
1125 AM CDT SAT AUG 24 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

1130 PM    BROWNLEE                  NE   WIND DAMAGE
08/23/02   EASTERN CHERRY                 MANY TREE LIMBS DOWN UP TO
                                          6 INCHES IN DIAMETER.

TRM

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE, NE
1239 PM CDT SAT AUG 24 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0050 AM    MILLS                     NE   WIND DAMAGE
08/23/02   KEYA PAHA                      SEVERE TREE DAMAGE FROM
                                          MILLS TO NIOBRARA RIVER...
                                          NUMEROUS LARGE LIMBS
                                          DOWN...MATURE TREES BROKEN
                                          OR BLOWN DOWN...SOME ROADS
                                          BLOCKED DUE TO FALLEN
                                          TREES.

JRS