Hail and Damaging Wind in Nebraska, June 4 to 5, 2010

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HASTINGS NE
1015 PM CDT FRI JUN 4 2010

.DISCUSSION...UPDATED THE FORECAST TO CUT BACK CHANCES OF
PRECIPITATION FROM THE FORECAST IN THE SOUTHERN CWA OVERNIGHT AND
INCREASE TO LIKELY IN THE FAR NORTHEASTERN CWA OVERNIGHT. AS THE
LOW-LEVEL JET DEVELOPS AND A PERTURBATION MOVES CLOSER...IT LOOKS
LIKE A REALLY GOOD CHANCE OF RAIN IN OUR NORTHEAST. ALREADY
NUMEROUS ACTIVITY IN NORTHERN NEBRASKA AND WILL CONTINUE TO MOVE
EAST SOUTHEAST.

&&

.PREV DISCUSSION... /ISSUED 657 PM CDT FRI JUN 4 2010/

AVIATION...00Z KGRI TAF. MOST OF THIS FORECAST CALLS FOR VFR
CONDITIONS. AS THE LOW-LEVEL JET INCREASES...SOME STORMS COULD
DEVELOP NEAR THE TERMINAL AND POINTS NORTH NEAR THE AREA OF BETTER
LOW-LEVEL CONVERGENCE. WITH A SMALL PERTURBATION SWINGING THROUGH
TONIGHT...THIS COMBINATION COULD GIVE A DECENT CHANCE FOR A
THUNDERSTORM TO OCCUR LATE EVENING INTO EARLY OVERNIGHT TONIGHT.
ONE MODEL IS ADVERTISING QUITE LOW STRATUS FOR SATURDAY...BUT
BACKING OFF OF THIS AND RAISING CEILINGS TO VFR AS THERE IS NOT
WIDE AGREEMENT FOR LOW STRATUS.

PREV DISCUSSION... /ISSUED 305 PM CDT FRI JUN 4 2010/

SHORT TERM...TONIGHT THROUGH 12Z SUNDAY. THE MAIN FORECAST
CONCERN WILL BE THE CHANCE OF THUNDERSTORMS TONIGHT. AFTERNOON
SURFACE ANALYSIS SHOWED A WEAK FRONTAL BOUNDARY LOCATED ACROSS
SOUTHERN NEBRASKA WHICH EXTENDED WEST/SOUTH INTO A TROUGH ACROSS
PARTS OF WESTERN KANSAS. DEWPOINTS NEAR THE FRONT HAVE CLIMBED
INTO THE UPPER 60S TO NEAR 70 IN PARTS OF SOUTHEAST NEBRASKA AND
THE 12Z NAM SHOWS A RIBBON OF HIGHER INSTABILITY IN THAT GENERAL
AREA LATE THIS AFTERNOON WITH 0-1KM MLCAPE VALUES RISING TO
2500-3500 J/KG. DEEP LAYER SHEAR SHOULD BE SUFFICIENT FOR A FEW
SUPERCELLS...BUT THE MAIN QUESTION IS THE CAP. H7 TEMPERATURES IN
WESTERN PARTS OF THE FORECAST AREA ARE EXPECTED TO BE 13 TO
14C...BUT WILL BE A FEW DEGREES COOLER IN EASTERN PARTS OF
NEBRASKA AND KANSAS. GENERALLY EXPECT STORMS TO FIRE IN PARTS OF
SOUTHEAST NEBRASKA...BUT THEY COULD GRADUALLY DEVELOP FARTHER WEST
INTO EASTERN PARTS OF THE FORECAST AREA.

ANOTHER CONCERN FOR TONIGHT IS AN INCREASING LOW LEVEL JET WITH
H85 WARM AIR ADVECTION INCREASING NORTH OF THE BOUNDARY. THE
LATEST RUC SHOWS THE NOSE OF THE LOW LEVEL JET FOCUSING ACROSS
SOUTH CENTRAL NEBRASKA NEAR THE INTERSTATE...AND GENERATES A FEW
THUNDERSTORMS IN THAT REGION THIS EVENING. THE 12Z NAM IS A LITTLE
SLOWER IN BRINGING THE LOW LEVEL JET NORTH...BUT IN THE END FOCUSES
THE MAIN CONVECTIVE THREAT A BIT FARTHER NORTH LATE TONIGHT AS AN
IMPULSE MOVES ACROSS SOUTHERN SOUTH DAKOTA/NORTHERN NEBRASKA. HAVE
INITIALLY SHOWN THE HIGHER POPS LATE THIS AFTERNOON/EVENING IN THE
SOUTH AND EAST PARTS OF THE FORECAST AREA...BUT WILL SHIFT THEM
NORTH WITH TIME.

A LINGERING SHOWER OR THUNDERSTORM IS POSSIBLE IN THE NORTH AND
EAST PORTION OF THE FORECAST ARE EARLY SATURDAY...OTHERWISE THE BULK
OF THE DAY SHOULD BE DRY AS DRIER SURFACE HIGH PRESSURE BUILDS
INTO THE CENTRAL PLAINS. TEMPERATURES WILL ALSO BE A LITTLE COOLER
TOMORROW WITH HIGHS RANGING FROM THE LOWER 80S NEAR ORD AND
GREELEY...TO THE LOWER 90S AROUND PLAINVILLE AND BELOIT. A FEW
THUNDERSTORMS COULD DEVELOP ACROSS PARTS OF EASTERN COLORADO AND
WESTERN KANSAS IN THE EASTERLY UPSLOPE FLOW SATURDAY
AFTERNOON/EVENING...BUT THEY SHOULD NOT MAKE IT THIS FAR EAST.

LONG TERM...12Z SUNDAY THROUGH FRIDAY.  SAME SONG DIFFERENT VERSE
AS WE BASICALLY STAY IN ZONAL FLOW THROUGH THE EXTENDED PERIOD WITH
WEAK WAVES AND SURFACE BOUNDARIES GIVING US OFF AND ON CHANCES FOR
THUNDERSTORMS.

STARTING OUT SUNDAY BELIEVE IT SHOULD BE DRY ACROSS THE AREA AS
UPPER LEVEL RIDGING AND SURFACE HIGH PRESSURE BUILD IN. SUNDAY NIGHT
BECOMES MORE PROBLEMATIC AS SOME MODELS HAVE BEEN BRINGING WEAK
SHORTWAVE OVER THE RIDGE AND INTO THE AREA GENERATING QPF...HOWEVER
BOTH GFS AND NAM HOLD SURFACE LOW WELL TO THE WEST AND SHOW THE BEST
CONVERGENCE FROM THE LOW LEVEL JET ALSO WEST AND NORTH OF OUR AREA.
PREVIOUS FORECAST HAD RAIN CHANCES IN FOR SUNDAY NIGHT AND WILL KEEP
IT THAT WAY TO AVOID FLIP FLOPPING. BY TUESDAY GFS AND EC TAKE THE
SURFACE LOW INTO SW/WRN KANSAS WITH AN EAST/WEST FRONTAL BOUNDARY
ACROSS THE STATE. APPEARS THIS BOUNDARY HANGS OUT DURING THE MIDDLE
OF THE WEEK BUT THE QUESTION WILL BE WHETHER IT IS OVER KANSAS OR
OKLAHOMA OR DRIFTS NORTH AND SOUTH. AS HAS BEEN THE CASE RECENTLY
TIMING OF ANY MID LEVEL DISTURBANCES WILL BE TRICKY.

BY THURSDAY GFS AMPLIFIES A RIDGE OVER THE PLAINS AS IT DIGS A
TROUGH INTO THE WEST. EC SIMILAR ALTHOUGH IT DOES NOT MOVE THE
TROUGH IN AS QUICKLY THUS THE AMPLIFICATION ON THE RIDGE NOT AS
STEEP. ONE IMPACT OF THIS LOOKS TO BE A LOW OVER TEXAS. THE GFS
MOVES THIS NORTH INTO CENTRAL KANSAS BY FRIDAY NIGHT BEFORE MINORING
IT OUT WHILE 00Z EC MOVES IT A LITTLE MORE NORTHEAST.

ALL IN ALL WILL KEEP RAIN CHANCES IN THE FORECAST STARTING SUNDAY
NIGHT AND GOING TIL THURSDAY. 20 TO 30 PERCENT CHANCES SEEM
REASONABLE FOR NOW UNTIL BOUNDARY LOCATION AND SHORTWAVE TIMING
BECOMES BETTER DEFINED.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

HEINLEIN

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE HASTINGS NE
849 PM CDT FRI JUN 4 2010

KSZ005>007-017>019-NEZ039>041-046>049-060>064-072>077-082>087-
051200-
PHILLIPS-SMITH-JEWELL-ROOKS-OSBORNE-MITCHELL-VALLEY-GREELEY-NANCE-
SHERMAN-HOWARD-MERRICK-POLK-DAWSON-BUFFALO-HALL-HAMILTON-YORK-
GOSPER-PHELPS-KEARNEY-ADAMS-CLAY-FILLMORE-FURNAS-HARLAN-FRANKLIN-
WEBSTER-NUCKOLLS-THAYER-
849 PM CDT FRI JUN 4 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL NEBRASKA AND
PORTIONS OF NORTH CENTRAL KANSAS.

.DAY ONE...TONIGHT.

SEVERE THUNDERSTORMS ARE POSSIBLE DURING THE LATE EVENING AND
OVERNIGHT HOURS...PRIMARILY NORTH OF INTERSTATE 80.
HOWEVER...THERE MAY BE AN ISOLATED SEVERE THUNDERSTORM OR TWO
DURING THE LATE EVENING AND EARLY OVERNIGHT HOURS SOUTH OF
INTERSTATE 80 AND NORTH OF THE NEBRASKA AND KANSAS STATE LINE. THE
PRIMARY HAZARDS FROM ANY STORMS THAT DEVELOP WILL BE HAIL TO THE
SIZE OF QUARTERS AND DAMAGING WINDS GREATER THAN 60 MPH. LOCALLY
HEAVY RAINFALL IS ALSO POSSIBLE.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

INTERMITTENT CHANCES FOR THUNDERSTORMS EXIST ACROSS THE OUTLOOK
AREA SUNDAY NIGHT THROUGH TUESDAY NIGHT...AND AGAIN ON THURSDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TONIGHT.

&&

MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING WEB PAGE:
   HTTP://WWW.WEATHER.GOV/HASTINGS  (ALL LOWERCASE)

HEINLEIN