River Flood Warning 98, NWS Des Moines, IA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
855 PM CDT THU OCT 29 2009

.UPDATE...
DRY SLOT HAS MADE SIGNIFICANT PROGRESS INTO IA THIS EVENING AND HAS
ENDED HEAVY RAIN THREAT OVER ALL BUT N CENTRAL AND E CENTRAL
COUNTIES.  HAVE AMENDED FORECAST TO DRAMATICALLY REDUCE POPS
OVERNIGHT CENTRAL AND WESTERN SECTIONS...AND LOWERED FROM
CATEGORICAL TO SCATTERED WORDING EAST BY 04Z WHEN EXTRAPOLATION
EXITS RAIN SHIELD FROM FORECAST AREA.  MADE SIMILAR CHANGES TO FLASH
FLOOD WATCH...CANCELING WHERE APPROPRIATE AND ENDING BY MIDNIGHT
ELSEWHERE.  THIS MAY STILL BE A TAD TOO LATE...BUT HEADING IN THE
RIGHT DIRECTION.  MAY CANCEL EARLY ONCE RAIN CLEARS AREA.  ALSO MADE
SOME MINOR TEMP/DEWPOINT CHANGES TO KEEP THEM STEADY UNTIL FROPA.

&&

.SHORT TERM...TONIGHT
RAIN AND THUNDERSTORMS CONTINUE TO OUR SW AND MOISTURE CHANNEL
INHIBITED FOR THE NEXT 12 TO 18 HOURS AS 50 TO 60KT H850 FLOW
CONTINUES FROM THE SW. WATER VAPOR IMAGERY SHOWS THE MAIN SYSTEM
JUST ROUNDING THE BEND ACROSS EASTERN OK. SFC LOW APPEARS TO BE
REORGANIZING OVER NORTHEAST OK. HT FALLS FROM 12Z AT H850 THROUGH
H500 SHOWED LITTLE EASTWARD TRANSLATION OF THE UPPER LEVEL
FEATURES...THUS THE MOISTURE CHANNEL WILL REMAIN IN PLACE FOR THE
NEXT 12 HOURS. QPF BEGINNING TO EXPAND AGAIN WITH THE NEXT
WAVE...WITH GOOD FORCING AND HIGH PWATS AND THE LOW FFG OVER THE
SOUTH AND EAST...ANY ADDITIONAL 1 TO 3 INCH RAINFALLS WILL POSE
PROBLEMS. RAIN SHOULD TAPER OFF AFT 06Z TNT AS DRY SLOT ENTERS THE
PICTURE WITH SOME RESIDUAL DRIZZLE BEFORE THE DRY SLOT TAKES OVER
THE AREA AFT 09Z. MINS WILL NOT DROP MUCH WITH STRONG SE
WINDS...RAIN...AND OVERCAST. SOME COOLER TEMPS WILL BE MOVING INTO
THE WEST TOWARD MORNING...THOUGH STILL MILD.

.LONG TERM...FRIDAY THROUGH THURSDAY
PRIMARY PRECIPITATION WILL BE DONE BY 12Z FRIDAY MORNING THROUGH THE
UPPER LEVEL TROUGH WILL STILL BE WEST OF THE AREA. STRONG SFC COLD
ADVECTION WILL BE PASSING THROUGH CNTRL IOWA FRIDAY MORNING AND
ACTUALLY LIFTING EAST/NORTHEAST THROUGH THE REMAINDER OF THE AREA
12-15Z AS COLD AIR WRAPS AROUND THE SYSTEM. THE RESULT WILL BE
FALLING TEMPERATURES IN THE MORNING WITH SOME REBOUND IN THE
AFTERNOON HOWEVER HIGH TEMPERATURES WILL LIKELY BE AROUND 12Z MOST
LOCATIONS. MOISTURE WILL BE QUITE LIMITED MUCH OF THE DAY THROUGH A
FEW SHOWERS WILL BE POSSIBLE OVER THE NORTH LATE FRIDAY INTO FRIDAY
EVENING AS THE WAVE TRANSLATES EAST ACROSS THE STATE.

COOL AND DRY CONDITIONS ARE EXPECTED ON SATURDAY WITH A BREEZY
NORTHWEST WIND. LOW LEVEL WARM ADVECTION COMMENCES SATURDAY NIGHT
AND WILL RESULT IN A WARMER DAY ON SUNDAY. WENT CONSERVATIVE ON
TEMPERATURES FOR SUNDAY AT THIS TIME THOUGH IF SUFFICIENT SUN IS
AVAILABLE...SOUTHWEST WINDS COULD EASILY PUSH HIGHS INTO THE 60S
OVER MUCH OF THE CENTRAL AND SOUTH. A SYSTEM MOVING THROUGH THE
NORTHWEST FLOW WILL AFFECT NORTHERN IOWA LATE IN THE DAY BRINGING AN
INCREASE IN CLOUD COVER AND POSSIBLY SOME LIGHT RAIN INTO THE
EVENING. NO SIGNIFICANT WEATHER NEXT WEEK...MONDAY THROUGH THURSDAY.
POTENTIAL FOR ANOTHER SYSTEM TO CLIP THROUGH TUESDAY AND TUESDAY
EVENING WITH ANOTHER POTENTIAL FOR LIGHT RAIN OTHERWISE DRY WITH
SEASONAL TEMPERATURES.

&&

.AVIATION...30/00Z
WIDESPREAD IFR/LIFR CONDITIONS...MAINLY DUE TO CIGS...COVER MUCH OF
IA EARLY THIS EVENING.  SHOWERS COVERED MUCH OF THE STATE AS WELL
WITH EMBEDDED THUNDER SE NEAR KOTM.  THIS PRECIP SHIELD SHOULD
CONTINUE LIFTING N AND E THIS EVENING WITH SHOWERS AND ISOLATED
STORMS DIMINISHING SW-NE THROUGH 07Z.  CIGS SHOULD REMAIN IFR FOR
SEVERAL HOURS EVEN AFTER PRECIP ENDS...FOLLOWED BY INCREASING WINDS
EARLY FRI MORNING.  CIGS SHOULD LIFT BECOMING MVFR/VFR FOR MUCH OF
FRI TOO.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...FLASH FLOOD WATCH N CENTRAL AND E
CENTRAL SECTIONS TIL MIDNIGHT.

&&

SHORT TERM...REV/SMALL
LONG TERM...DONAVON
AVIATION...SMALL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
1129 AM CDT THU OCT 29 2009

IAZ017-026>028-036>039-046>050-058>062-070>075-081>086-092>097-
301630-
CERRO GORDO-FRANKLIN-BUTLER-BREMER-HAMILTON-HARDIN-GRUNDY-BLACK HAWK-
GREENE-BOONE-STORY-MARSHALL-TAMA-GUTHRIE-DALLAS-POLK-JASPER-
POWESHIEK-CASS-ADAIR-MADISON-WARREN-MARION-MAHASKA-ADAMS-UNION-
CLARKE-LUCAS-MONROE-WAPELLO-TAYLOR-RINGGOLD-DECATUR-WAYNE-APPANOOSE-
DAVIS-
1129 AM CDT THU OCT 29 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

OCCASIONAL THUNDERSTORMS WILL AFFECT THE AREA AGAIN THIS AFTERNOON AND
INTO TONIGHT...ENDING AFTER MIDNIGHT. A FEW STORMS COULD BE STRONG...
PRODUCING SMALL HAIL AND GUSTY WINDS. LOCALLY HEAVY RAINFALL IS
ALSO LIKELY WHICH COULD LEAD TO SOME FLASH FLOODING IN THE OUTLOOK
AREA.

A FLASH FLOOD WATCH IS IN EFFECT FOR THE AREA THROUGH EARLY FRIDAY MORNING.
PLEASE REFER TO THE NATIONAL WEATHER SERVICE WEBSITE AT WEATHER.GOV/DESMOINES
FOR FURTHER DETAILS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

.NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED...BUT ANY HEAVY RAINFALL
REPORTS WOULD BE APPRECIATED.

IAZ004>007-015-016-023>025-033>035-044-045-057-301630-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-POCAHONTAS-HUMBOLDT-
WRIGHT-SAC-CALHOUN-WEBSTER-CRAWFORD-CARROLL-AUDUBON-
1129 AM CDT THU OCT 29 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

.NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

REV

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
421 PM CDT THU OCT 29 2009

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0405 PM     HEAVY RAIN       SSW GENEVA              42.67N 93.13W
10/29/2009  M3.30 INCH       FRANKLIN           IA   TRAINED SPOTTER

            AMOUNT FALLEN SINCE 6AM.

&&

JH