Hail and Lightning Strike in Nebraska, August 12, 2001

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
221 AM CDT SUN AUG 12 2001

...POPS AND TEMPS WILL BE A CHALLENGE...

UPPER PATTERN CONTINUES TO FEATURE A RIDGE OVER WESTERN NOAM WHILE A
TROF SPANS CENTRAL AND EASTERN CANADA AND EXTENDS INTO ADJACENT
AREAS OF THE NORTHERN STATES. VERY WEAK AND DIFFUSE SURFACE
PRESSURE PATTERN WITH A WEAK TROF THAT EXTENDS ACROSS NORTHERN SOUTH
DAKOTA INTO SOUTHERN MONTANA.

FORECAST WILL BE DIFFICULT AT BEST DUE TO ETA/AVN DIFFERENCES. EACH
MODEL HAS RESOLVED LARGE VARIATIONS IN THE STRENGTH AND TRACK OF
WAVES ACROSS THE PLAINS THROUGH MONDAY NIGHT.

BOTH MODELS HAVE CONSISTENTLY RESOLVED FEATURE CURRENTLY EJECTING
FROM EASTERN WYOMING...ALTHOUGH PRECIP COVERAGE IS NOT NEARLY AS
EXTENSIVE AS MODEL FORECASTS. FEATURE IS IN VICINITY OF LEFT EXIT
REGION OF LOCALIZED SPEED MAX. IMMEDIATELY DOWNSTREAM OF WAVE...AMPLE
MID LEVEL INSTABILITY EXISTS OVER THE CWA AND SURFACE BASED
INSTABILITY WILL INCREASE TODAY. OVERALL...THIS FEATURE STILL LOOKS
POTENT ENOUGH TO WARRANT A CHANCE POP. NOT EXPECTING CLOUD COVER TO
BE NEARLY AS EXPANSIVE AS MODEL FORECASTS...GUIDANCE TEMPS ARE A
PRODUCT OF THE MODEL CLOUD COVER AND ARE LIKELY TO BE TOO COOL. TEMP
PROFILES WILL BE NEARLY UNCHANGED TODAY SO MOST AREAS SHOULD REACH
MAXES SIMILAR TO YESTERDAY.

LARGE SCALE SUBSIDENCE WILL INCREASE TONIGHT IN WAKE OF EXITING
FEATURE. UPPER RIDGE WILL SLOWLY EDGE INTO THE PLAINS WITH THE AXIS
NEAR THE DIVIDE BY 12Z. HIGH AND DRY TONIGHT WITH SLIGHTLY COOLER
MINS DUE TO ABSENCE OF CLOUDS.

LITTLE CHANGE MONDAY WITH THE RIDGE EXPECTED TO EDGE EASTWARD.
MAX SPREADING OF LAYER Q-VECS/SUBSIDENCE TO TRAVEL ALONG THE MISSOURI
RIVER INTO EASTERN NEBRASKA BY 00Z TUESDAY...SUNSHINE WILL BE
PREVALENT. ANOTHER DEGREE OR TWO OF LOW LEVEL WAA SHOULD PUSH MOST
AREAS TO AROUND 90.

MUCH PREFER THE DRY ETA SOLUTION FOR MONDAY NIGHT VERSUS THE WET AVN
SOLUTION. MODELS GENERALLY AGREE ON THE POSITION OF UPPER FEATURES.
STRONGEST WAVE WILL CROSS SOUTH DAKOTA WHILE ANOTHER SHOULD ENTER
EASTERN COLORADO. NATURALLY...THE ETA HAS RESOLVED BEST DIVERGENCE...
PV ADVECTION AND MID LEVEL FRONTOGENESIS IN THESE SAME AREAS. LEE
TROF WILL REMAIN WEST OF THE CWA. PRESSURE GRADIENT EAST OF LEE
TROF WILL BEGIN TO INCREASE SUSTAINING WINDS/MIXING...THUS WARMER
GUIDANCE MINS LOOK ACCURATE.

IN THE EXTENDED...STILL WAITING ON MRF...BUT DO NOT EXPECT TO MAKE
ANY CHANGES. FROPA TUESDAY NIGHT INTO WEDNESDAY WITH A CHANCE OF
PRECIP. COOLER TEMPS BY WEDNESDAY PERSISTING THURSDAY. WARMING AGAIN
BY FRIDAY AS SOUTHERLY RETURN FLOW DEVELOPS.

.LBF...NONE.

DJB

NEZ004>010-022>029-035>038-056>059-069>071-121630-

SEVERE WEATHER OUTLOOK FOR WESTERN AND NORTH CENTRAL NEBRASKA
NATIONAL WEATHER SERVICE NORTH PLATTE NE
530 AM CDT SUN AUG 12 2001

...STORM SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY OR TONIGHT
ACROSS WESTERN AND NORTH CENTRAL NEBRASKA...

THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE ACROSS MOST OF WESTERN AND
NORTH CENTRAL NEBRASKA TODAY.

ONGOING THUNDERSTORMS ACROSS NORTHERN PORTIONS OF THE OUTLOOK AREA
THIS MORNING WILL CONTINUE TO MOVE SOUTHEAST ACROSS THE REMAINDER OF
THE OUTLOOK AREA THROUGH THE AFTERNOON. THESE STORMS ARE ASSOCIATED
WITH AN UPPER LEVEL DISTURBANCE MOVING INTO WESTERN AND NORTHERN
PORTIONS OF NEBRASKA. THE LACK OF DEEP LOW LEVEL MOISTURE WILL HELP
PREVENT THE ATMOSPHERE FROM BECOMING EXTREMELY UNSTABLE AND
WIDESPREAD SEVERE WEATHER IS NOT EXPECTED. HOWEVER A FEW ISOLATED
THUNDERSTORMS MAY REACH SEVERE LIMITS WITH LARGE HAIL THE PRIMARY
THREAT. MANY OF THE STORMS THROUGH THE DAY WILL BE CAPABLE OF
PRODUCING BRIEF HEAVY RAINFALL...SMALL HAIL AND WIND GUSTS UP TO 45
MPH.

DP