Hail in Iowa, July 27, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
334 AM CDT THU JUL 27 2006

.DISCUSSION...

SHORT TERM...TODAY AND TONIGHT. THUNDERSTORMS CHANCES...ALBEIT
GENERALLY SMALL...ARE THE MAIN FORECAST CHALLENGE. WATER VAPOR
STLT IMAGERY SHOWED MAIN SHORT WAVE TROUGH TO AFFECT FORECAST AREA
WAS PUSHING TOWARD CNTRL SD/NWRN NEBR BY 08Z. EXTRAPOLATION ON
CURRENT MOVEMENT WOULD PUT IT INTO VCNTY OF ECNTRL NEBR BY EARLY
AFTERNOON. QUESTION IS HOW MUCH PCPN WILL IT GENERATE AS IT MOVES
ACROSS THE CWA. THRU 18Z LOW LVL JET IS MEAGER AT BEST BUT SOME
850 MB THETA E ADVCTN WAS NOTED THROUGH 12Z ON NAM ALONG WITH LOW
LVL MOISTURE CONVERGENCE NERN/ERN NEBR THRU 18Z. ISOLD CONVECTION
THAT DEVELOPED EARLIER ON OUTFLOW BOUNDARY FM OLU-OFK HAD DISPTD
BUT A FEW SHOWERS REMAINED JUST SW OF THE CWA AS OF 08Z. WHILE QPF
FM GFS IS GENERALLY ABSENT OVER THE FCST AREA TODAY...00Z NAM
GENERATED SAME MUCH OF THE DAY WHILE UKMET AND 4.5KM WRF
COMPOSITE REFLECTIVITY DVLPD QPF/RETURNS OVR ERN NEBR IN 12Z-18Z
PD. LATTER DVLPD INCREASING RETURNS BEGINNING AROUND 10Z SPREADING
IT E/SE WHILE WEAKENING IT INTO EARLY AFTN BEFORE GENERATING BULK
OF PCPN WITH SHORTWV ENERGY MOSTLY SE THROUGH E OF THE CWA. BASED
FORECAST ON BLEND OF GFS AND WRF 4.5KM AND THUS INSERTED SMALL
POPS MOST ZONES THIS MORNING SHIFTING CHCS THIS AFTN TO ERN ZONES.
NAM AND WRF 4.5KM DO DVLP LATE AFTN CONVECTION ON SFC TROF
AXIS/DRYLINE CNTRL NEBR...BUT FEEL IF THIS DOES INDEED OCCUR IT
WOULD NOT MOVE INTO NWRN ZONES TILL EVENING. SO INCLUDED NWRN
ALONG WITH ERN ZONES AND INSERTED SOME EVENING POPS AS WELL.
BETTER FORCING AND LOW LVL THETA E ADVCTN SHIFTS ENE OF FORECAST
AREA BY THEN SO PCPN MAY HAVE ALREADY SHIFTED OUT OF THE CWA.
WITH PLENTY OF MID LVL MOISTURE AVAILABLE...CLOUDS INTO EARLY AFTN
COULD HOLD TEMPS DOWN A BIT SERN ZONES...BUT CLEARING SHOULD OCCUR
ACROSS THE NW. THUS WENT CLOSER TO MAV TEMPS NWRN ZONES WHERE
AFTERNOON SUN LOOKS ABUNDANT AND WITH A BLEND OF MAV/NAM ELSEWHERE.

AFTER THIS EVENING RAIN CHCS GREATLY DIMINISH UNTIL PROBABLY THE TUE-
WED PD WITH FORECAST FOCUS TURNING TO HEAT AS UPPER RIDGE BUILDS
ACROSS PLAINS. TEMPERATURES SHOULD MAKE A RUN AT 100 EACH DAY MOST
AREAS FROM FRIDAY THROUGH SUNDAY AT LEAST. ANY WEAK WAVE RIDING
OVER RIDGE AT THE RIGHT TIME PROVIDING A BIT MORE OF A SW WIND
AND BETTER DOWNSLOPE/MIXING IN THE AFTN COULD POSSIBLY PUSH READINGS
SVRL DEGREES ABOVE 100. FOR NOW MADE LTL CHANGES TO TEMPS WITH
SIMILAR HIGHS/LOWS THROUGH MONDAY ALTHOUGH IT WAS NOTED THAT BOTH
THE GFS AND CMC BROUGHT A SUB TROPICAL TYPE UPPER LOW TOWARD NEBR
IN THE LATE SUN/MON PD. THIS WILL HAVE TO BE MONITORED BECAUSE
ASSOCD MOISTURE WITH IT COULD TRIGGER ISOLD CONVECTION AND TEMPS A
CATEGORY OR TWO LOWER THAN FORECAST...SPCLY MONDAY. RIDGE
EVENTUALLY SHIFTS E BY MID WEEK WITH SOME TIMING DIFFERENCES BTWN
00Z GFS AND ECMWF WITH THE LATTER SLOWER. ALTHOUGH GFS MAY BE TOO
FAST IN BRINGING FRONT THROUGH FCST AREA BY 00Z WED...DID
INTRODUCE SLGT POPS NWRN ZONES TUE AFTN NWRN ZONES TO ACCOUNT FOR
A ECMWF/GFS BLEND.

&&

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

&&

CHERMOK

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
647 AM CDT THU JUL 27 2006

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-280200-
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-
647 AM CDT THU JUL 27 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN NEBRASKA
AND SOUTHWEST IOWA.

.DAY ONE...TODAY AND TONIGHT

THERE IS A CHANCE OF THUNDERSTORMS ACROSS MAINLY FAR EASTERN
NEBRASKA AND WESTERN IOWA THIS MORNING AND THEN GENERALLY ALONG
AND EAST OF THE MISSOURI RIVER THIS AFTERNOON AND EVENING.
THUNDERSTORMS THIS MORNING WILL LIKELY BE ISOLATED AND NOT SEVERE.
THUNDERSTORMS DEVELOPING THIS AFTERNOON INTO EARLY THIS EVENING
SHOULD BE STRONGER AND A FEW COULD PRODUCE GUSTY WINDS AND SMALL
HAIL.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

HOT AND HUMID WEATHER IS FORECAST FROM FRIDAY THROUGH NEXT
TUESDAY OVER MUCH OF THE OUTLOOK AREA. TEMPERATURES ARE EXPECTED
TO CLIMB WELL INTO THE 90S EACH DAY WITH SOME READINGS POSSIBLY
SURPASSING 100. OVERNIGHT CONDITIONS WILL BE MUGGY WITH MOST LOWS
REMAINING ABOVE 70. AFTERNOON HEAT INDEX VALUES MAY EXCEED 105
EACH DAY.

THERE IS A CHANCE OF THUNDERSTORMS OVER THE AREA LATE TUESDAY INTO WEDNESDAY.

.SPOTTER INFORMATION STATEMENT...

STORM SPOTTER ACTIVATION IS NOT EXPECTED TODAY OR TONIGHT.