Hail and Damaging Winds in Nebraska, July 12, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
310 AM CDT THU JUL 12 2007

.DISCUSSION...

NOT MUCH CHANGE IN THE UPPER AIR PATTERN THIS MORNING WITH REGION
IN NWRLY FLOW BETWEEN UPPER LOW CIRCULATING OVR SRN HUDSON BAY
AND RIDGE OF HIGH PRESSURE EXTENDING ACROSS THE WESTERN CONUS.
LATEST MSAS SFC ANALYSIS SHOWS LARGE AREA OF HI PRESS EXTENDING FM
ERN NEB AND ERN KS INTO MO WITH A SECONDARY HIGH TO OUR NW OVR THE
DAKOTAS AND CANADIAN PRAIRIES. DESCENT MID LEVEL MOISTURE HAS
ADVECTED INTO THE FORECAST AREA PER 00Z UAA AND LOCAL OBS. A FEW
ISOLATED SHOWERS HAVE BEEN POPPING UP AND BEST INDICATION IS DUE TO WK
ISENTROPIC UPGLIDE OFF SEEN OFF RUC ON 300K SFC AND WHERE
STRONGEST THETA E ADVECTION IS OCCURING.

ISOLATED TO SCATTERED TSRA COULD BE POSSIBLE ACROSS MUCH OF THE
FORECAST AREA THE REST OF THE MORNING HOURS WITH THETA E ADVECTION
CONTINUING THRU NOON. CONFIDENCE IS RATHER LOW...THUS THE LOW POPS.
CDFNT WL DROP DOWN FM THE DAKOTAS AND INTO NRN NEB BY 18Z TODAY
AND COULD BE THE FOCUS FOR ANY TSTM DEVELOPMENT ACROSS SERN
NEB/SWRN IA THIS AFTERNOON. AHEAD OF THIS FRONT...MODERATE
INSTABILITY (3000J/KG SBCAPE) AND 30 TO 40 KTS OF BULK SHEAR COULD
SUPPORT A FEW ISOLATED HAIL CORES...MAINLY SOUTH OF I-80...HOWEVER
LARGE SCALE FORCING IS VERY WEAK. WL CONTINUE TO CARRY LOW POPS TO
COVER THIS AS CONFIDENCE IS RELATIVELY LOW. 00Z FORECAST MODELS
CONTINUE TO SLOW THIS FRONT DOWN AS HAVE PREVIOUS MODEL RUNS. WITH
THAT SAID...HAVE CONTINUED SMALL POPS INTO THE EVENING HOURS OVR
EXTREME SERN NEB/SWRN IA AND MAY NEED TO BE REVISITED IF LATER
MODEL RUNS SLOW THE FNT DOWN EVEN MORE.

FRIDAY SHOULD BE LAST COOL DAY AS SFC HIGH PRESSURE BUILDS OVER
THE FORECAST AREA. WL SEE A WARMING TREND THRU THE WEEKEND AND
INTO NEXT WEEK AS UPPER RIDGE BEGINS TO BUILD EWD INTO THE CNTRL
PLAINS BY MID NEXT WEEK.

&&

.AVIATION...

CONDITIONS SHOULD BE MAINLY VFR AT ALL THREE TAF SITES...KOFK...
KOMA AND KLNK...THROUGH TONIGHT. CEILINGS SHOULD BE MOSTLY AT OR
ABOVE 5000 FEET THROUGH THE DAY. FRONTAL BOUNDARY WILL BE PUSHING
SOUTHWARD ACROSS THE AREA. IF THUNDERSTORMS CAN GET GOING DURING
THE AFTERNOON...THEY COULD AFFECT PARTS OF SERN NE. AT THIS TIME...
THE CHANCE SEEMS TOO LOW TO MENTION IN THE KLNK AND KOMA TAFS.
FOR TONIGHT...IT APPEARS ANY CLOUD COVER WILL BE ABOVE 10000 FEET
WITH LIGHT NORTH OR NORTHEAST WINDS AS HIGH PRESSURE BUILDS ACROSS
THE DAKOTAS AND MINNESOTA.

&&

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

GRIFFIS/MILLER

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
530 AM CDT THU JUL 12 2007

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-130030-
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 AM CDT THU JUL 12 2007

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

.DAY ONE...TODAY AND TONIGHT

ISOLATED NON SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS MUCH OF THE
OUTLOOK AREA THROUGH NOON.

THERE IS A BETTER CHANCE OF THUNDERSTORMS MAINLY ALONG AND SOUTH
OF INTERSTATE 80 LATER THIS AFTERNOON. LARGE HAIL IS POSSIBLE WITH
THESE THUNDERSTORMS IF THEY DO DEVELOP. THESE POSSIBLE STORMS
WOULD FORM AHEAD OF AN APPROACHING COLD FRONT IN A MODERATELY
UNSTABLE ENVIRONMENT.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION COULD POSSIBLY BE NEEDED SOUTH OF INTERSTATE 80
THIS AFTERNOON.

GRIFFIS