Hail in Nebraska, June 19, 2002

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
241 PM CDT WED JUN 19 2002

...SVR WX POTENTIAL TONIGHT...POSITION OF THE FRONT LEADS TO FCST
CHALLENGES OF THE PERIOD...

SFC FRONT POSITIONED FROM JUST W OF ONL TO W OF LXN TO E OF GLD AS OF
18Z. NW-NE FLOW ON THE BACK SIDE WITH DECENT S-SW WINDS AHEAD OF IT.
WATER VAPOR IMAGERY SHOWS SHORT WAVE TROF COMING OUT OF NERN CO
ATTM...BUT ONLY SCT CU ALONG THE FOOTHILLS. 18Z LBF SOUNDING SHOWS
HUGE CAP IN THE MID LEVELS...HENCE THE FLAT CU OUTSIDE. LAPS DATA
CONFIRMS THIS WITH CIN VALUES AOB -200 J/KG. LAPS SHOWS WEAKEST CAP
FROM BOYD INTO NRN HOLT COUNTIES AS OF 18Z...AND A WEAKENING NEAR
MCK. DEW POINTS FROM JUST BEHIND TO AHEAD OF THE FRONT WELL INTO THE
60S AND 18Z SOUNDING SHOWS SOME DEPTH TO THE MOISTURE.

FRONT HAS SO FAR PASSED THRU THE CWA QUIETLY...BUT WOULD EXPECT
SOME TSRA DEVELOPMENT IN BOYD/ERN HOLT COUNTIES POSSIBLY LATE
THIS AFT INTO THIS EVENING AS CAP CONTINUES TO WEAKEN. IF THESE DO
DEVELOP ALONG/NEAR THE FRONT...DEEP LAYER SHEAR PROGGED BY THE ETA
APPROACHES 50 KTS...ALONG WITH CAPE VALUES OF 3000 J/KG OR SO.
THIS WOULD SUGGEST THAT THERE COULD BE A FAIR AMOUNT OF
ROTATION POTENTIAL WITH THE STORMS. FURTHER S AND W...CAP SHOULD HOLD
UNTIL AFTER SUNSET. OTHER AREA OF CONCERN WILL BE FROM BBW TO CURTIS
IN VICINITY OF FRONT. FEELING IS ENTIRE SYSTEM WILL BECOME LINEAR
THROUGH THE EVENING WITH THE ERN LBF CWA ON THE FRINGE. HOWEVER...AS
THE FRONT BECOMES ORIENTED MORE W TO E...LL JET DEVELOPS AFTER
SUNSET IN A NEARLY PERPENDICULAR FASHION. THIS SHOULD LEAD TO
ELEVATED CONVECTIVE POTENTIAL OVERNIGHT...WITH PW VALUES RUNNING
OVER 1.5 INCHES...SO MCS SHOULD PRODUCE MUCH NEEDED RAINFALL IN
PARTS OF THE SW. ALL THIS LEADS TO LIKLEY POPS IN THE E/SW...
TRAILING BACK TO NOTHING IN THE FAR NW. LOOK FOR A 21Z SOUNDING FROM
LBF DUE TO IHOP...

LEFTOVER MORNING CONVECTION POSSIBLE IN THE S THU MORNING. POSITION
OF FRONT THO WILL BE THE DETERMINING FACTOR ON PRECIP CHANCES THU
NIGHT. IF CONVECTION DEVELOPS AS PER THE ETA TONIGHT...FRONT SHOULD
BE IN C KS BY THU AFTERNOON. NEXT SHORT WAVE TROF COMES OUT OF THE
ROCKIES THU EVENING INDUCING SFC CONVERGENCE IN THE PANHANDLE WHICH
THEN MOVES EWD OVERNIGHT. DECENT LLJ AGAIN BECOMES ESTABLISHES OVER
THE HIGH PLAINS AND SHOULD LEAD TO TSRA DEVELOPMENT...ALTHOUGH SCT
IN NATURE...FROM W TO E THRU THE NIGHT.

AFTER A BRIEF COOL DOWN FOR THU...HEIGHTS RISE AND SRLY WIND RETURNS
TO PUMP TEMPS BACK UP TO NEAR 90 OR SLIGHTLY ABOVE FOR FRIDAY INTO
THE WEEKEND. SOME VARIATION FROM RUN TO RUN IN THE GLOBAL MODEL...
AND THE GLOBAL IS FASTER WITH THE CUTOFF LOW THAN THE ECMWF. IN
GENERAL THO...WITH SWRLY FLOW CONTINUING INTO THE WEEKEND...HAD TO
LEAVE PRECIP CHCS IN AS EACH ONE REINFORCES HIGH PLAINS SFC TROF
AND SLIDES IT EWD. FRIDAY LOOKS PRIMARILY DRY AS RIDGE BUILDS IN
AHEAD OF CUTOFF SYSTEM TO THE W. THEN FOR THE FIRST OF THE WEEK...
WRN SYSTEM GETS EJECTED IN THE NRN STREAM AND RIDGE REBUILDS
LEADING TO WARMER TEMPS AND LACK OF PRECIP MECHANISM. NEXT BREAKDOWN
BEGINS TUES INTO WED...HENCE THE PRECIP CHCS LEFT IN FOR THAT TIME
FRAME.

.LBF...NONE.

JWS

NEZ004>010-022>029-035>038-056>059-069>071-094-192030-

HAZARDOUS WEATHER OUTLOOK FOR WESTERN AND NORTH CENTRAL NEBRASKA
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1144 AM CDT WED JUN 19 2002

...STORM SPOTTER ACTIVATION MAY BE NEEDED LATE THIS AFTERNOON INTO
TONIGHT FOR PORTIONS OF WESTERN AND NORTH CENTRAL NEBRASKA...

THERE IS A CHANCE OF THUNDERSTORM DEVELOPMENT ACROSS ALL OF THE
OUTLOOK AREA THIS AFTERNOON AND TONIGHT. HOWEVER THE GREATEST RISK
OF SEVERE THUNDERSTORM DEVELOPMENT WILL BE ALONG AND EAST OF AN
IMPERIAL TO NORTH PLATTE TO BASSETT LINE.

A SURFACE FRONT WILL CONTINUE TO MOVE SOUTHWARD THROUGH THE OUTLOOK
AREA THIS AFTERNOON AND INTO THE EVENING HOURS. TEMPERATURES AHEAD OF
THE FRONT ARE EXPECTED TO REACH THE 90S...ALLOWING THE ATMOSPHERE TO
BECOME MODERATELY UNSTABLE.  AS THIS UNSTABLE AIR COLLIDES WITH THE
FRONT...THUNDERSTORMS ARE EXPECTED TO DEVELOP. AS AN UPPER LEVEL
DISTURBANCE MOVES INTO THE OUTLOOK AREA THUNDERSTORMS ARE
EXPECTED TO INCREASE IN COVERAGE AND INTENSITY. THE STORMS MAY
FORM INTO A LINE WITH DAMAGING WINDS AND LARGE HAIL THE PRIMARY
SEVERE THREATS. HOWEVER...AS STORMS FORM THIS AFTERNOON ALONG THE
COLD FRONT...AN ISOLATED TORNADO WILL BE POSSIBLE.