Hail and Damaging Wind in Nebraska, June 17, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
300 PM CDT TUE JUN 17 2008

.DISCUSSION...

UPPER RIDGE AXIS REMAINS NEARLY IN PLACE INTO FRIDAY WITH MAIN
SFC-H85 MOISTURE AXIS PERSISTING JUST TO THE WEST OF THE CWA
THROUGH TOMORROW WITH ANY CONVECTION POSSIBLY MUDDLING THINGS UP
AFTER THAT. EARLIER WEAK H85 THETA E ADVECTION HELPED FUEL MORNING
SHOWERS/TSTMS WHICH WERE BEGINNING TO REGENERATE OVR SCNTRL SD
JUST NW OF THE CWA. WEAK WARM FRONT APPEARED TO BE DVLPG FM NWRN
CWA NW INTO AREA OF SD CONVECTION WITH CU FIELD INCREASING NW OF
LNK FEEDING N INTO FRONT. IN ADDITION...UPSTREAM WAVE GENERATING
CONVECTION OVR ERN MT WILL BE DROPPING SE OVER RIDGE LATER THIS
EVENING. THUS...UPPED POPS TNGT...ESPECIALLY NWRN ZONES...AND
ADDED TO ALL BUT FAR SE AS EARLIER PCPN TRENDS HAVE BEEN FOR
STRONGER ACTIVITY TO REMAIN MORE LOCKED TO MOISTURE AXIS WITH
DISSIPATION/WEAKENING OF ANY ACTIVITY THAT MOVED OFF OF IT.
COUNTING ON ENOUGH RESIDUAL CLOUDS FROM DECAYING CONVECTION
...HOWEVER...TO KEEP LOWS UP A BIT OVER THOSE OBSERVED THIS
MORNING.

OBVIOUSLY GFS SUFFERS FM CONVECTIVE FEEDBACK WED...BUT UPPER WAVE
THAT STLT PICTURES SHOWED THIS AFTN PIVOTING AROUND W COAST UPPER
LOW INTO WA WILL BE TOPPING RIDGE AND DROPPING SEWD ACROSS THE CWA
WED. EVEN NAM WHICH WASN/T AS BULLISH IN GENERATING A QPF BULLSEYE
OVER THE CWA WED AFTN DID BASICALLY WEAKEN CAP WITH AFTN HEATING
AS WAVE MOVES OVER AND MOIST AXIS SHIFTS EWD INTO WRN CWA. THUS
INCLUDED POPS ALL ZONES...HIGHEST NWRN 1/2 OR SO ATTM MORE IN LINE
WITH GFS ENSEMBLE MEAN DEPICTION. COULD BE ENOUGH CLOUDS LINGERING
OR REDEVELOPG W/HTG TO KEEP READINGS FROM GETTING MUCH ABOVE 80
MOST AREAS. WAVE SHOULD CONT DROPPING SEWD WED NGT BUT DOUBT
THINGS WILL IMPROVE AS QUICKLY AS GFS SUGGESTED DUE TO IT/S
FEEDBACK AND SUBSIDENCE ISSUES. HOWEVER...DID START TRIMMING POPS
BACK BY THU AFTN AND LEFT FRI DRY FOR NOW. AGAIN WITH MAIN RIDGE
AXIS REMAINING TO OUR W INTO FRIDAY...NWRLY UPPER FLOW PUTS CWA
ON TARGET FOR ANY RIDGE-RUNNERS THRU THAT PD. AMOUNT OF RESIDUAL
CLOUDS THU COULD KEEP CNTRL/SRN ZONES FM WARMING AS MUCH AS NRN
ZONES...BUT SLIGHTLY WARMER TEMPERATURES CONTINUED FOR FRI WITH
SEEMINGLY LESS PCPN/CLOUD CHCS.

UPPER HGTS BUILDING THRU THE WEEKEND SHOULD PROMOTE WARMING
TEMPERATURES. ALTHOUGH 12Z OPERATIONAL GFS HAD LTL/NO SUPPORT FM
00Z ECMWF AND 00Z GFS ENSEMBLES IN BRINGING SFC FNT INTO CWA SAT
NGT/SUN...00Z GEMS AND ECMWF DID GENERATE QPF SAT NGT. THUS LEFT
IN SLGT CHC TSTMS SAT NGT. EVEN WARMER TEMPS LOOK PROBABLE IN
MON-TUE PD AS RIDGE AXIS SHIFTS EVEN FTHR EWD. WL LEAVE REST OF
FCST DRY AS TIMING OF ANY WAVES VIRTUALLY IMPOSSIBLE AND HIGH HGTS
SHOULD LIMIT PCPN CHCS SOMEWHAT. THIS CAN/WL BE ADDRESSED IN
FUTURE FORECASTS HOWEVER.

&&

.AVIATION...
FOR TAF SITES KOMA...KLNK AND KOFK THRU 18/18Z

VFR CONDITIONS EXPECTED THROUGH THRU THE PD WITH SCT CU DURING THE
AFTERNOON HOURS. VERY ISOLATED SHOWERS AND THUNDERSTORMS COULD ROLL
THRU KOFK AND KLNK THRU THE PD...HOWEVER TOO ISOLATED TO MENTION IN
THE TAF.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

CHERMOK/GRIFFIS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
530 PM CDT TUE JUN 17 2008

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-181230-
MONONA-HARRISON-SHELBY-POTTAWATTAMIE-MILLS-MONTGOMERY-FREMONT-
PAGE-KNOX-CEDAR-THURSTON-ANTELOPE-PIERCE-WAYNE-BOONE-MADISON-
STANTON-CUMING-BURT-PLATTE-COLFAX-DODGE-WASHINGTON-BUTLER-
SAUNDERS-DOUGLAS-SARPY-SEWARD-LANCASTER-CASS-OTOE-SALINE-
JEFFERSON-GAGE-JOHNSON-NEMAHA-PAWNEE-RICHARDSON-
530 PM CDT TUE JUN 17 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
IOWA...WEST CENTRAL IOWA...EAST CENTRAL NEBRASKA...NORTHEAST
NEBRASKA AND SOUTHEAST NEBRASKA.

.DAY ONE...TONIGHT AND WEDNESDAY

ISOLATED SEVERE THUNDERSTORMS WILL BE POSSIBLE TONIGHT...MAINLY WEST
OF NORFOLK AND COLUMBUS. SCATTERED SEVERE THUNDERSTORMS MAY
DEVELOP WEDNESDAY. LARGE HAIL AND DAMAGING WINDS WILL BE THE
PRIMARY HAZARDS.

A MID LEVEL RIDGE OF HIGH PRESSURE IS IN PLACE OVER THE WESTERN
U.S. AND THIS PLACES THE FORECAST AREA AT RISK FOR THUNDERSTORMS
WITH EACH WEATHER DISTURBANCE THAT TOPS THE RIDGE AND MOVES INTO
THE PLAINS. THE MOISTURE AXIS INITIALLY IS WEST OF THE OUTLOOK
AREA...THUS STORMS WILL TEND TO DECREASE IN COVERAGE AS THEY
MOVED EAST OF THE DEEPER MOISTURE. LATER TONIGHT AND
WEDNESDAY...THE ENVIRONMENT SHOULD SUPPORT MORE SCATTERED
THUNDERSTORMS ACROSS MORE OF THE OUTLOOK AREA WITH INCREASED MOISTURE
TO WORK WITH.

RIVER FLOODING WILL CONTINUE ALONG THE NISHNABOTNA RIVER NEAR
HAMBURG...AND ALONG THE MISSOURI RIVER DOWNSTREAM FROM NEBRASKA
CITY.

.DAYS TWO THROUGH SEVEN...WEDNESDAY NIGHT THROUGH TUESDAY

THUNDERSTORMS ARE POSSIBLE WEDNESDAY NIGHT THROUGH THURSDAY
NIGHT...AND AGAIN SATURDAY NIGHT. LARGE HAIL AND DAMAGING WINDS
WILL BE POSSIBLE WITH THE STORMS THROUGH THURSDAY.

.SPOTTER INFORMATION STATEMENT...

STORM SPOTTER ACTIVATION MAY BE NEEDED FOR PARTS OF THE OUTLOOK
AREA...MAINLY WEST OF COLUMBUS TONIGHT AND WEDNESDAY ACROSS THE
OUTLOOK AREA.

ZAPOTOCNY