Severe Thunderstorm Warning 89, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
227 PM CDT FRI JUN 29 2001

...CHC OF THUNDERSTORMS AND TEMPS ARE THE BIGGEST CHALLENGES THRU
PERIOD...

UPPER RIDGE NEAR THE FOUR CORNERS REGION CONTINUES TO FLATTEN IN THE
WESTERN SECTIONS MAKING A POSITIVE TILT INTO THE NORTHERN PLAINS.
SATELLITE IMAGERY SHOWS CONVECTION STARTING TO FIRE ALONG A SFC
BOUNDARY IN THE PANHANDLE.  THIS BOUNDARY WAS EVIDENT ON THE CYS
RADAR OVER THE LAST FEW HOURS.  TEMPS HAVE JUMPED INTO THE MID 90S
OVER THE SOUTHWEST ZONES WITH DEWPOINTS IN THE MID 60S TO NEAR 70.

THE AVN AND ETA ARE IN GOOD AGREEMENT THROUGH 12Z SAT BUT THEN
DIVERGE...ESPECIALLY IN THE PCPN FIELD.  HAVE LEANED TOWARD THE ETA
WITH THE PCPN CONTINUING TO FIRE ALONG THE FRONT AS IT MOVES SOUTH
ACROSS WESTERN NE.  THE AVN MOVES THE PCPN EAST ACROSS SD.  THIS
SEEMS A LITTLE SUSPECT SINCE THE BEST LIFT...INSTABILITY...AND
MOISTURE WILL BE IN PLACE OVER NE AND CORFIDI VECTORS SUGGEST SOUTH
SOUTHEAST MOVEMENT.

THE CONVECTION OVER THE SOUTHWEST ZONES IS EXPECTED TO MOVE
SOUTHEAST IN ACCORDANCE WITH THE CORFIDI VECTORS.  EXPECT MOST OF
CONVECTION TO MOVE SOUTH OUT OF THE CWA BY EARLY EVENING.  THIS
MOVEMENT IS ALSO IN AGREEMENT WITH OTHER STORMS THAT DEVELOPED OVER
THE LAST 24 HOURS.  ANOTHER BOUNDARY EVIDENT ON SATELLITE EXTENDS
FROM NORTHEAST TO SOUTHWEST SOUTH DAKOTA. WITH LAPS CAPE VALUES
EXCEEDING 4500 J/KG ACROSS THE NORTHERN PART OF THE CWA...EXPECT
THE NEXT CONVECTION TO FIRE AS THE SFC BOUNDARY IN SD SLIDES
SOUTHEAST INTO THE HIGH INSTABILITY. AGAIN...THE STORMS WILL SLIDE
SOUTHEAST OVER THE NORTHEAST PORTION OF THE CWA TONIGHT.  AS THIS
MOVES SOUTHEAST...IT WILL MOVE OUT OF THE LLJ SUPPORT SO EXPECT IT
TO SLOWLY DIMINISH AFTER MIDNIGHT.  ANOTHER LARGE COMPLEX DEVELOPS
IN WESTERN SOUTH DAKOTA AFTER MIDNIGHT ON THE NOSE OF THE LLJ AND
ALONG A DEVELOPING COLD FRONT.  THIS AGAIN PUSHES SOUTHEAST INTO THE
NORTHWEST SECTIONS OF THE CWA LATE TONIGHT.

THE COLD FRONT SLIDES SOUTHEAST ACROSS THE CWA ON SAT WITH GOOD
INSTABILITY ALONG THE FRONT...CAPES AROUND 3000 J/KG.  THE FRONT
EXTENDS FROM NORTHEAST NE SOUTHWEST INTO THE CENTRAL PORTIONS OF
THE PANHANDLE BY 18Z SAT AND THEN BECOMES STATIONARY OVER THE
SOUTHERN THIRD OF NE BY 00Z SUN. WITH GOOD SHEAR TO THE NORTH OF
THE FRONT...THERE MAY BE ENOUGH ROTATION FOR TORNADIC DEVELOPMENT
SAT AFTERNOON.  H8 TEMPS DROP OFF BEHIND THE FRONT SO WILL KEEP
COOLER CONDITIONS OVER THE NORTHEAST. THE SOUTHERN AND WESTERN
PORTIONS WILL STILL REMAIN FAIRLY WARM.

SAT NIGHT THE ETA DEVELOPS ANOTHER THUNDERSTORM COMPLEX IN
NORTHEAST WY AND MOVES IT SOUTHEAST INTO THE NORTHERN PORTION OF THE
CWA BY 10Z-12Z SUN. THE RIDGE FLATTENS CONSIDERABLY BY THIS TIME
WITH MOST STORMS MOVES EAST SOUTHEAST. A SFC TROF DEVELOPS IN THE
WEST AGAIN WITH SOUTHERLY FLOW BRINGING IN VERY WARM AIR.  TEMPS
SHOULD WARM AGAIN INTO THE UPPER 80S TO LOWER 90S.

WITH RIDGING IN THE WEST AND SHORTWAVES MOVING THROUGH THE FLOW...
EXTENDED LOOKS FAIRLY ACTIVE WITH CHC OF SHOWERS AND
THUNDERSTORMS. WILL NOT CHANGE MUCH AT THIS TIME.

.LBF...NONE.

DDB

NEZ004>010-022>029-035>038-056>059-069>071-292045-

SEVERE WEATHER OUTLOOK FOR WESTERN AND NORTH CENTRAL NEBRASKA
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1113 AM CDT FRI JUN 29 2001

...STORM SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND
TONIGHT...

THERE IS A CHANCE OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING
OVER PORTIONS OF NORTHERN NEBRASKA...MAINLY NORTH OF AN ELLSWORTH TO
THEDFORD TO ONEILL LINE. THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE
ACROSS THE REMAINDER OF THE OUTLOOK AREA HOWEVER...THEY ARE NOT
EXPECTED TO REACH SEVERE LIMITS.

HUMID CONDITIONS WILL CONTINUE ACROSS THE OUTLOOK AREA AS SOUTH WINDS
BRING MOIST AIR FROM THE GULF OF MEXICO.  THE ATMOSPHERE WILL BECOME
INCREASINGLY UNSTABLE THIS AFTERNOON AS TEMPERATURES WARM INTO THE
90S. BY AFTERNOON...AN UPPER LEVEL DISTURBANCE PUSHING INTO NORTH
CENTRAL NEBRASKA WILL INITIATE ISOLATED THUNDERSTORMS.  SOME OF THESE
THUNDERSTORMS COULD REACH SEVERE LIMITS...WITH LARGE HAIL AND
DAMAGING WINDS THE PRIMARY THREATS.

ELSEWHERE...ANY THUNDERSTORMS THAT DEVELOP MAY PRODUCE BRIEF HEAVY
RAIN...AND POSSIBLY SMALL HAIL IN SOME LOCATIONS.

DP

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE, NE
236 PM CDT FRI JUN 29 2001

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

0143 PM    11 S OSHKOSH              NE   .75 INCH HAIL
06/29/01   GARDEN
RLB