Severe Thunderstorm Warning 142, NWS Des Moines, IA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
635 AM CDT FRI JUN 18 2010

...UPDATED FOR 12Z AVIATION DISCUSSION...

.DISCUSSION...
SQUALL LINE THAT MOVED THRU LAST NIGHT AND ERY THIS MRNG HAS PUSHED
AN OUTFLOW BNDRY ACRS THE STATE...BUT THE REAL CDFNT IS STILL WELL
OFF THE WEST.  MCS IS DECAYING RPDLY AS NEW CONVECTION IS BCMG
ESTABLISHED OVR NEBRASKA.  AMS SHOULD DESTABILIZE RATHER QUICKLY TDA
AND SEE NO REASON WHY THINGS WOULDN'T FIRE BY ERY THIS AFTN.  WILL
GO WITH ENHANCED WORDING FOR SEVERE WX THIS AFTN WITH THIS.  WITH
ERY DVLPMT WILL OPT TO KEEP TEMPERATURES DOWN JUST A TOUCH FROM
MOS.  SHOULD SEE CONVECTION MOVE TO THE E AND S OF THE STATE FOR THE
MOST PART LATER TNGT INTO SAT...BUT BREAK WILL BE SHORT LIVED. -PNA
PTRN CONTINUES WITH NO REAL LETUP IN SIGHT.  ROUNDS OF TSRA THIS
WEEKEND WILL LKLY LEAVE BEHIND FLOODING IN MOST RIVER BASINS AND
FLASH FLOODING WILL BE POSSIBLE WITH SAT NGT AND SUN LOOKING LIKE
THE BEST CHANCE FOR THAT.  NO REAL BIG CHNGS IN GOING FCSTS OTR THAN
TO SHAVE A FEW DEGREES OFF TEMPS.  CLOUDS AND RAIN WILL MAKE IT
DIFFICULT TO GET MUCH PAST THE MID 80S IN MOST AREAS.  WILL CONTINUE
WITH THE ESF FOR ALL OF THE FORECAST RAIN AND POTENTIAL FLOOD/FLASH
FLOOD ISSUES.

&&

.AVIATION...
18/12Z...A COLD FRONT WILL ENTER NW IA THIS AFTERNOON AND MOVE ACRS
THE STATE THIS EVENING.  VFR CONDITIONS WILL BE WIDEPSREAD IN MUCH
OF THE STATE TODAY WITH MVFR TO IFR NEAR ISOLD TO SCT TSRA THIS
MORNING IN WESTERN IN CNTRL IA.  MORE WIDEPSREAD THUNDERSTORM
ACTIVITY IS EXPECTED THIS AFTERNOON AS THE FRONT PUSHES INTO THE
STATE.  DRIER AIR WILL FILTER IN BEHIND THE FRONT WITH VFR
CONDITIONS BECOMING WIDESPREAD OVERNIGHT WITH UNLIMITED CIGS AND
VSBYS AFTER 06Z.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

SHORT TERM...MS JUN 10
LONG TERM...MS JUN 10
AVIATION...COGIL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
505 AM CDT FRI JUN 18 2010

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-191100-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-SAC-CALHOUN-
WEBSTER-HAMILTON-HARDIN-GRUNDY-BLACK HAWK-CRAWFORD-CARROLL-GREENE-
BOONE-STORY-MARSHALL-TAMA-AUDUBON-GUTHRIE-DALLAS-POLK-JASPER-
POWESHIEK-CASS-ADAIR-MADISON-WARREN-MARION-MAHASKA-ADAMS-UNION-
CLARKE-LUCAS-MONROE-WAPELLO-TAYLOR-RINGGOLD-DECATUR-WAYNE-APPANOOSE-
DAVIS-
505 AM CDT FRI JUN 18 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS WILL BECOME NUMEROUS FROM MID DAY INTO THE
EVENING HOURS. SEVERE THUNDERSTORMS WILL BE POSSIBLE BY MID DAY
INTO THE EVENING HOURS. THE PRIMARY THREATS WILL BE FOR WIND GUSTS
OF 60 MPH OR MORE...LARGE HAIL...AND LOCALLY HEAVY RAINFALL. THERE IS
ALSO AN ISOLATE TORNADO THREAT.

RIVER FLOOD WARNINGS REMAIN IN EFFECT FOR PARTS OF THE AREA. PLEASE
REFER TO THE NATIONAL WEATHER SERVICE WEBSITE AT
WEATHER.GOV/DESMOINES FOR FURTHER DETAILS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

PERIODS OF THUNDERSTORMS WILL CONTINUE THROUGH WEDNESDAY NIGHT. A
FEW OF THE STORMS MAY BE SEVERE...ESPECIALLY SATURDAY NIGHT INTO
SUNDAY...HOWEVER THE GREATEST THREAT IS FOR HEAVY RAINFALL. THE
HEAVIEST RAINFALL IS LIKELY BETWEEN SATURDAY NIGHT AND TUESDAY.
THREE TO FOUR INCHES OF RAIN IS QUITE LIKELY OVER CENTRAL
IOWA...WITH SOME AREAS RECEIVING OVER 6 INCHES.

RIVER FLOOD WARNINGS REMAIN IN EFFECT FOR PARTS OF THE AREA.  A
WATCH/WARNING/ADVISORY IS IN EFFECT FOR THE AREA. PLEASE REFER TO
THE NATIONAL WEATHER SERVICE WEBSITE AT WEATHER.GOV/DESMOINES FOR
FURTHER DETAILS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING BETWEEN
100 PM AND 900 PM.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
347 AM CDT FRI JUN 18 2010

IAZ033-044-045-180945-
CARROLL-CRAWFORD-SAC-
347 AM CDT FRI JUN 18 2010

...SIGNIFICANT WEATHER ADVISORY...

AT 343 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM OVER CENTRAL CRAWFORD COUNTY...MOVING NORTHEAST
AT 30 MPH.

NICKEL SIZE HAIL...BRIEF HEAVY DOWNPOURS...ARE POSSIBLE WITH THIS
STORM.

* THE THUNDERSTORM WILL BE NEAR...
  DELOIT BY 400 AM CDT...
  VAIL BY 410 AM CDT...
  WESTSIDE BY 420 AM CDT...
  ARCADIA BY 425 AM CDT...
  BREDA BY 435 AM CDT...
  AUBURN BY 445 AM CDT...

SEEK SHELTER IN A STURDY STRUCTURE UNTIL THIS STORM HAS PASSED.

COGIL