Severe Thunderstorm Warning 240, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
248 PM CDT FRI JUL 25 2003

...FORECAST CHALLENGE WILL BE POPS TONIGHT INTO THE WEEKEND...

AT 19Z TEMPERATURES WERE AT OR ABOVE THE CENTURY MARK WEST OF AN ONL-
BBW-LXN LINE. SURFACE LOW CENTER REMAINS OVER CENTRAL SOUTH DAKOTA
AND AN ASSOCIATED TROUGH EXTENDING SOUTHWEST ACROSS WESTERN NEBRASKA
INTO SOUTHEAST COLORADO. BOUNDARY WILL NUDGE SLOWLY EAST THIS
EVENING WITH MODELS DIFFERING IN INITIATION OF CONVECTION AS MAIN
COLD FRONTAL BOUNDARY AND FORCING LIES WELL NORTH. BY 21Z MESOETA
MODEL SOUNDING MIXES OUT INVERSION LAYER THROUGH 03Z ACROSS THE
NORTHWEST AS SURFACE TEMPS PEAK. VISIBLE SATELLITE SHOWS FEW
CLOUDS ACROSS THE PANHANDLE EAST TO TROUGH AXIS WITH CONVECTION
DEVELOPING OVER THE MOUNTAINS FROM SOUTHEAST WY INTO CO.

ALTHOUGH INSTABILITY GREATEST ACROSS THE NORTH CENTRAL SUBSIDENCE
ALOFT AND CAP SHOULD INHIBIT THUNDERSTORM DEVELOP UNTIL LATE THIS
EVENING. INCOMING H5 WAVE MOVING EAST INTO THE PANHANDLE WILL
CONTINUE TO INITIATE ISOLATED STORMS OVER THE PANHANDLE. THEN
OVERNIGHT A SLIGHT CHANCE OF THUNDERSTORMS TO THE EAST. PWS ARE
AROUND AN INCH TONIGHT WITH HIGH BASED STORMS TO GENERATE MORE WIND
THAN RAINFALL. TEMPERATURES TONIGHT WILL BE CLOSE TO PREVIOUS NIGHT.

SATURDAY COOLER TEMPERATURES FOR THE NORTHWEST AS FRONTAL BOUNDARY
PUSHES SOUTH ACROSS THE FORECAST AREA DURING THE DAY. THE FRONTAL
BOUNDARY WILL PUSH EAST OF THE FA BY EVENING WITH CONVECTION DUE TO
FIRE NORTH OF THE SURFACE BOUNDARY AS DISTURBANCES MOVE EAST. UPPER
RIDGE WILL BEGIN TO REBUILD BACK TO THE WEST ON SUNDAY AS CONVERGENT
FLOW INCREASES ACROSS NEB. THE UPSLOPE FLOW WILL HELP TO MOISTEN TO
ATMOSPHERIC PROFILE WITH PW TO OVER 1.5 INCHES AND LOCALIZED HEAVY
RAINFALL WITH STORMS THAT DEVELOP AS LIGHT WINDS ALOFT RESULT IN
SLOW STORM MOVEMENTS.

MONDAY FRONTAL BOUNDARY TO SHIFT FURTHER SOUTHEAST INTO OKLAHOMA
WITH CHANCE FOR CONVECTION TO MOVE SOUTH OUT OF THE SOUTHWEST DURING
THE MORNING. THEN DRY AND COOLER THROUGH MIDWEEK.

AFTER A COOL MIDWEEK TEMPERATURES WILL START TO REBOUND ON FRIDAY.
TUESDAY THROUGH FRIDAY THE UPPER HIGH CENTER WILL BUILD EAST WITH
THE NORTHWEST COOLER FLOW TO SHIFT EAST OF THE PLAINS AS THE UPPER
RIDGE FLATTENS OUT ON FRIDAY. WARM AIR ADVECTION INCREASES DURING THE
PERIOD AS THE UPPER RIDGE BUILDS EAST AND WILL RAISE H85 TEMPERATURES
FROM THE UPPER TEENS ON TUESDAY TO LOWER 30S IN THE WEST ON FRIDAY.
THE CHANCE FOR RAINFALL WILL BE LIMITED THROUGH FRIDAY AS THE GULF IS
CLOSED AND THE NORTHWEST FLOW IMPEDES MOISTURE BELOW 10 KFT.

.LBF...NONE.

KECK

NEZ004>010-022>029-035>038-056>059-069>071-094-261030-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORTH PLATTE NE
350 PM CDT FRI JUL 25 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND NORTH CENTRAL
NEBRASKA.

.DAY ONE... TONIGHT.

THUNDERSTORMS ARE EXPECTED TO MOVE OUT THE HIGH PLAINS OF COLORADO
AND WYOMING AND MAY HOLD TOGETHER INTO WESTERN PORTIONS OF THE
OUTLOOK AREA DURING THE EVENING HOURS. THUNDERSTORM DEVELOPMENT WILL
BE POSSIBLE ALONG A SURFACE TROUGH OVER EXTENDING FROM NEAR
VALENTINE TO IMPERIAL. THESE STORMS MAY CONTINUE TO MOVE EAST
THROUGH THE EARLY MORNING HOURS. WEAK WINDS AND EXTREMELY WARM
TEMPERATURES ALOFT WILL TEND THE INHIBIT THE DEVELOPMENT OF SEVERE
THUNDERSTORMS THROUGH AT LEAST SUNDAY MORNING.

.DAYS TWO THROUGH SEVEN... SATURDAY THROUGH THURSDAY

THERE IS A RISK OF SEVERE THUNDERSTORMS TOMORROW AFTERNOON AND
TOMORROW NIGHT ACROSS SOUTHERN AND EASTERN PORTIONS OF THE OUTLOOK
AREA. THIS AREA OF GREATEST CONCERN WILL BE SOUTH OF A BIG SPRINGS
TO ONEILL LINE.

MOISTURE WILL INCREASE NORTH OF A FRONT EXPECTED TO BE ANCHORED NEAR
THE NEBRASKA AND KANSAS BORDER. THIS INCREASE IN MOISTURE... AND
STRONG AFTERNOON HEATING WILL CREATE VERY UNSTABLE ATMOSPHERIC
CONDITIONS. AS A RESULT SEVERE THUNDERSTORMS MAY DEVELOP LATE IN THE
DAY...WITH LARGE HAIL AND DAMAGING WIND GUSTS.

THUNDERSTORMS ARE AGAIN POSSIBLE IN NORTH CENTRAL AND CENTRAL
THROUGH WESTERN AND SOUTHWEST NEBRASKA SUNDAY AND SUNDAY NIGHT...
BUT SEVERE WEATHER IS NOT EXPECTED WITH THEM.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEED SATURDAY EVENING ACROSS SOUTHERN AND
EASTERN PORTIONS OF THE OUTLOOK AREA.

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