Severe Thunderstorm Warning 191, NWS Des Moines, IA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
225 AM CDT WED JUL 9 2003

MAIN FORECAST ISSUE WILL BE DYNAMIC WARM SEASON SEVERE WEATHER
PATTERN SETTING UP OVER CWA THIS MORNING. 00Z SYNOPTIC SETTING
FEATURED COUPLED JETS AT 300 MB OVER SD WITH PRESSURE FALLS AT 40 M
AT 500 MB OVER ERN MT...A DEEP DEVELOPING HIGH PLAINS TROF AT 700 MB
WITH SURFACE WARM FRONT EXTENDING THROUGH NEBRASKA INTO THE SW
CORNER OF IA. ELEVATED FRONT AT 850 STRADDLED CENTRAL IOWA FROM
AROUND KFSD TO KDBQ. ELEVATED CU DEVELOPING IN WESTERN IOWA ALONG
THE ELEVATED FRONT EXPECTED TO PRODUCE MULTICELL STORMS WITH THE
POTENTIAL FOR FLASH FLOODING EARLY THIS MORNING WITH GOOD ELEVATED
CAPES AND PWATS AROUND 1.7 INCHES OVERNIGHT.  MCS NOW OVER NORTHERN
PLAINS IS ANTICIPATED TO  INTENSIFY IN THE 08-10Z TIME
FRAME...ACCELERATING INTO S-WESTERN IOWA AS A STRONG BOWING ECHO OR
LEWP TYPE STRUCTURE. STORMS TRACK DEPICTED IN MODEL OUTPUT
PROPAGATES EASTWARD INTO THE CWA AROUND 09Z AND COLD FRONT PUSHES
THROUGH BY EARLY AFTERNOON. SBCAPES SOUTH OF SURFACE BOUNDARY IN
SOUTHERN IOWA WERE IN THE 4500-5000 J/KG ACCORDING TO LAPS DATA LAST
AFTERNOON...HOWEVER THE TIMING OF THIS EVENT WILL KEEP CAPES MUCH
LOWER...HOWEVER THE CONVECTIVE MODE WILL SUPPORT DAMAGING WINDS
GIVEN THE INTENSITY OF THE SURFACE LOW 1000MB PROGGED AND UNSTABLE
LL LAPSE RATES.

WILL BUMP POPS ACROSS THE BOARD IN THE ZONES AND GRIDS WHILE OTHER
FORECAST CONSIDERATION WILL BE PRECIP EFFECTS OF ON TODAYS
TEMPERATURES. ALTHOUGH PROBLEMATIC...AM HESISTANT TO STRAY FAR FROM
GOING FORECAST AS SOME RECOVERY WILL BE POSSIBLE OVER SOUTHWEST
AFTER CONVECTION PASSES THIS AFTERNOON. WILL SHIP GRIDS/ZONES EARLY
THIS MORNING IN ANTICIPATION OF SEVERE WEATHER.

RUSSELL

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-092300-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
432 AM CDT WED JUL 9 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL IOWA.

.DAY ONE...TODAY

WIDESPREAD THUNDERSTORMS WILL AFFECT MOST OF CENTRAL IOWA TODAY. THE
MAIN THREATS WILL BE VERY HEAVY RAINS PRODUCING FLASH FLOODING...AS
WELL AS THE POTENTIAL FOR DAMAGING WINDS. THE FLASH FLOODING RISK
WILL BE MAINLY FROM AN OTTUMWA TO DES MOINES AND CARROLL LINE AND
NORTHWARD. THE BEST POTENTIAL FOR DAMAGING WINDS WILL BE ALONG AND
SOUTH OF U.S. HIGHWAY 30. THE THREAT FOR SEVERE WEATHER WILL
DIMINISH DURING THE AFTERNOON HOURS FROM WEST TO EAST ACROSS CENTRAL
IOWA AS A STRONG LOW PRESSURE SYSTEM RACES ACROSS THE STATE.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH MONDAY.
SEVERAL DRY DAYS ARE FORECAST BEFORE THE NEXT CHANCE FOR
THUNDERSTORMS ON MONDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS LIKELY TODAY.

&&

MORE INFORMATION CAN BE OBTAINED AT WWW.CRH.NOAA.GOV/DMX (ALL LOWER
CASE).

RUSSELL

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
0207 AM CDT WED JUL 09 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0202 AM    1 S VAIL                  IA   1.00 IN HAIL
07/09/03   CRAWFORD

SJT