Severe Thunderstorm Warning 28, NWS Des Moines, IA

000 
WWUS53 KDMX 261926
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
226 PM CDT SUN APR 26 2009

IAC029-262000-
/O.CON.KDMX.SV.W.0028.000000T0000Z-090426T2000Z/
CASS IA-
226 PM CDT SUN APR 26 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM CDT
FOR CASS COUNTY...

AT 224 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED
NEAR LEWIS...OR 75 MILES SOUTH OF IDA GROVE...MOVING NORTHEAST AT 40
MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  ATLANTIC...ATLANTIC AIRPORT AND CUMBERLAND BY 230 PM CDT...
  WIOTA BY 240 PM CDT...
  ANITA BY 245 PM CDT...

THIS INCLUDES INTERSTATE 80 BETWEEN MILE MARKERS 55 AND 72.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. IF A TORNADO
IS SPOTTED... ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A STURDY
STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.

THIS STORM HAS A HISTORY OF PRODUCING DESTRUCTIVE WINDS IN FAR 
SOUTHEASTERN POTTAWATTAMIE COUNTY. 

&&

LAT...LON 4138 9517 4151 9503 4150 9471 4137 9472
      4115 9504 4115 9516 4116 9517
TIME...MOT...LOC 1925Z 220DEG 37KT 4132 9503

$$

JUNGBLUTH

000 
WWUS53 KDMX 261940
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
240 PM CDT SUN APR 26 2009

IAC029-262000-
/O.CON.KDMX.SV.W.0028.000000T0000Z-090426T2000Z/
CASS IA-
240 PM CDT SUN APR 26 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM CDT
FOR EASTERN CASS COUNTY...

AT 239 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE
EXTENDING FROM WIOTA TO CUMBERLAND...MOVING NORTHEAST AT 40 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  ANITA BY 250 PM CDT...

THIS INCLUDES INTERSTATE 80 BETWEEN MILE MARKERS 62 AND 72.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE FOR DAMAGING WINDS...FALLING TREES AND FLYING DEBRIS. MOVE
INDOORS AND STAY AWAY FROM WINDOWS. IF YOU LIVE IN A MOBILE HOME...
SEEK SHELTER IN A STURDY BUILDING.

&&

LAT...LON 4151 9492 4150 9471 4137 9472 4124 9492
TIME...MOT...LOC 1940Z 229DEG 34KT 4145 9487 4126 9488

$$

JUNGLUTH

000 
WWUS53 KDMX 261955
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
255 PM CDT SUN APR 26 2009

IAC029-262004-
/O.EXP.KDMX.SV.W.0028.000000T0000Z-090426T2000Z/
CASS IA-
255 PM CDT SUN APR 26 2009

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN CASS COUNTY EXPIRES AT
300 PM CDT...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED AND NO LONGER
APPEARED TO BE SEVERE.

REPORT TORNADOES...WIND IN EXCESS OF 50 MPH...HAIL LARGER THAN ONE 
HALF INCH...OR STORM DAMAGE BY CALLING LOCAL LAW ENFORCEMENT AND 
ASKING THEM TO RELAY THE REPORT TO THE NATIONAL WEATHER SERVICE.

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A TORNADO 
WATCH REMAINS IN EFFECT UNTIL 800 PM.

LAT...LON 4151 9492 4150 9471 4137 9472 4124 9492
TIME...MOT...LOC 1954Z 229DEG 34KT 4153 9474 4134 9475

$$

JUNGBLUTH

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DES MOINES IA
1250 PM CDT SUN APR 26 2009

.UPDATED FOR THE 12Z AVIATION DISCUSSION...

.SHORT TERM /TODAY/...
ACTIVE FORECAST CONTINUES TODAY...WITH MORE ROUNDS OF SHOWERS AND
THUNDERSTORMS EXPECTED TODAY. ONGOING ACTIVITY CONTINUES ACROSS THE
NORTHEASTERN TWO THIRDS OF THE CWA ASSOCIATED WITH A SHORTWAVE THAT
WILL MOVE OUT OF THE AREA WITHIN THE NEXT FEW HOURS. ADDITIONAL
ACTIVITY CONTINUES TO PUSH NORTHEASTWARD TOWARD THE AREA FROM SE
NE AND NE KS. THIS AREA OF -TRW ASSOCIATED WITH A SHORTWAVE NOSING
UP INTO NRN OK/CNTRL KS AND IS EXPECTED TO CONTINUE PUSHING ENE THIS
MORNING. THEREFORE EXPECT THE STORMS ACROSS NE/KS TO MOVE THROUGH
PORTIONS OF THE WESTERN/CENTRAL CWA THIS MORNING. AS THIS WAVE LIFTS
OUT...SFC WARM FRONTAL BOUNDARY CURRENTLY POSITIONED JUST TO THE
SOUTH OF THE CWA WILL PUSH NORTHWARD THROUGH THE DAY. SFC TROUGH
AXIS/WARM FRONT TO BE STRETCHING ACROSS THE NORTHWESTERN PORTION OF
THE CWA BY LATE THIS AFTERNOON. EXPECT REDEVELOPMENT OF STORMS ALONG
AND AHEAD OF THIS BOUNDARY ACROSS MUCH OF THE CWA THROUGHOUT THE
AFTERNOON HOURS. MOISTURE TRANSPORT VECTORS ORIENTED RIGHT INTO THE
WESTERN/NORTHERN CWA BY LATE THIS AFTERNOON. ABUNDANT MOISTURE IN
PLACE SHOULD SET THE STAGE FOR SOME DECENT RAINFALL AMOUNTS WITH
WIDESPREAD AMOUNTS OF A HALF AN INCH TO AN INCH WITH LOCALLY HIGHER
AMOUNTS POSSIBLE. SEVERE POTENTIAL CONTINUES AS WELL...ALTHOUGH
SHAPE OF THE CAPE MORE LONG/SKINNY WITH UNIDIRECTIONAL SHEAR SO
ANTICIPATE MORE OF A LARGE HAIL/DAMAGING WIND THREAT.

.LONG TERM /TONIGHT-SATURDAY/...
HEAVY RAIN AND THUNDERSTORMS THE MAIN CONCERN FOR TONIGHT INTO EARLY
MONDAY. DEEP MOIST AIRMASS FED BY STRONG LOW LEVEL MOISTURE
TRANSPORT WILL EXIST ACROSS CENTRAL IOWA TONIGHT IN SFC WARM SECTOR
AND AHEAD OF FIRST OF TWO UPPER LEVEL SHORT WAVES TO TRAVERSE
THE REGION OVER THE NEXT 36 HOURS. STRONG LIFT IN ENTRANCE REGION OF
STRENGTHENING UPPER LEVEL JET AND INCREASING LOW LEVEL CONVERGENCE
ALONG ADVANCING COLD FRONT WILL BE THE MAIN CULPRITS. A COLD FRONT
PASSAGE IS PREFERRED GIVEN ITS PARALLEL ORIENTATION TO THE UPPER
LEVEL FLOW. A LARGELY UNIDIRECTIONAL WIND PROFILE WILL SUPPORT
TRAINING OF THUNDERSTORMS...WITH A SLOW EASTWARD TRANSLATION. SO
HEAVY RAIN...AND POTENTIALLY EXCESSIVE RAIN WILL EXIST. WIDESPREAD 2
TO 3 INCH AMOUNTS ARE LIKELY TONIGHT...WITH LOCALLY AS MUCH AS 5
INCHES...ESPECIALLY OVER THE SOUTHEASTERN TWO THIRDS OF THE AREA.
WILL BE ISSUING A FLASH FLOOD WATCH FOR THE THIS AREA DUE TO
EXPECTED RAINFALL RATES HAVING THE POTENTIAL TO OVERWHELM GROUND
ABSORPTION CAPABILITY. WILL ALSO HAVE TO BE WARY OF SEVERE
THUNDERSTORM POTENTIAL WILL LIKELY BE ONGOING THIS EVENING. WITH A
50+KT LOW LEVEL JET FEEDING UP ALONG THE FRONT EARLY
TONIGHT...DAMAGING WINDS FROM THE STRONGER THUNDERSTORMS WILL BE THE
MAIN SEVERE WEATHER THREAT. IF ANY SURFACE BASED INSTABILITY CAN BE
REALIZED LATE IN THE DAY...THEN THERE WOULD ALSO BE A THREAT OF
ISOLATED TORNADOES THIS EVENING GIVEN THE HIGH LOW-LEVEL
SHEAR...POTENTIAL LOW-LEVEL CAPE...LOW LCLS AND DEWPOINT
DEPRESSIONS.

THE SECOND SHORTWAVE DUE TO APPROACH THE AREA MONDAY AFTERNOON MAY
HOLD UP THE EASTWARD PROGRESSION OF THE FRONT MORE THAN THE MODELS
SUGGEST AND THIS WILL HAVE TO BE WATCHED FOR POSSIBLY INCREASING
POPS MORE ACROSS THE AREA ON MONDAY. THEREAFTER EXPECT A PERIOD OF
DRY WEATHER FOR TUESDAY...AND POSSIBLY MUCH OF WEDNESDAY...THOUGH
SOME SHOWERS/STORMS MAY START TO AFFECT WESTERN AREAS LATE
WEDNESDAY. BELOW NORMAL TEMPERATURES CAN BE EXPECTED THROUGH THE
FIRST HALF OF THE WEEK THANKS TO FLOW EMANATING FROM CANADIAN HIGH
PRESSURE WITH A NORTH TO EAST WIND COMPONENT.

&&

.AVIATION...26/18Z
WIDESPREAD CONVECTION IS ANTICIPATED THROUGH THE PERIOD WITH PERIODS
OF HEAVY RAINFALL. LIKELY IFR CONDITIONS OR BELOW FOR PERIOD
ESPECIALLY THIS EVENING WEST AND AFTER MIDNIGHT EAST. THE WIND WILL
SWITCH FROM THE NORTHWEST OVERNIGHT AS A COLD FRONT MOVES THROUGH.
GRADUALLY IMPROVING CONDITIONS BEHIND THE BOUNDARY AS THUNDERSTORMS
END.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
ADAIR-ADAMS-APPANOOSE-BLACK HAWK-BOONE-BREMER-BUTLER-CASS-CLARKE-
DALLAS-DAVIS-DECATUR-GRUNDY-GUTHRIE-HARDIN-JASPER-LUCAS-MADISON-
MAHASKA-MARION-MARSHALL-MONROE-POLK-POWESHIEK-RINGGOLD-STORY-
TAMA-TAYLOR-UNION-WAPELLO-WARREN-WAYNE.

&&

SHORT TERM/AVIATION...ALBRECHT/DONAVON
LONG TERM...MOYER

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
448 AM CDT SUN APR 26 2009

IAZ004>007-015>017-023>026-033>036-044>046-057-271000-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-SAC-CALHOUN-WEBSTER-HAMILTON-
CRAWFORD-CARROLL-GREENE-AUDUBON-
448 AM CDT SUN APR 26 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS TODAY WILL BECOME MORE NUMEROUS LATE THIS
AFTERNOON AND THIS EVENING. THUNDERSTORMS COULD BE SEVERE WITH
DAMAGING WINDS AND HAIL UP TO THE SIZE OF GOLF BALLS THE MAIN
THREATS. ISOLATED TORNADOES ARE ALSO POSSIBLE LATE THIS AFTERNOON
AND EARLY THIS EVENING. HEAVY RAINFALL MAY LEAD TO LOCALIZED MINOR
FLOODING.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

A CHANCE OF THUNDERSTORMS RETURNS TO THE AREA WEDNESDAY THROUGH
FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED TODAY AND EARLY TONIGHT.

IAZ027-028-037>039-047>050-058>062-070>075-081>086-092>097-271000-
BUTLER-BREMER-HARDIN-GRUNDY-BLACK HAWK-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-
448 AM CDT SUN APR 26 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS TODAY WILL BECOME MORE NUMEROUS TONIGHT.
THUNDERSTORMS COULD BE SEVERE WITH DAMAGING WINDS AND HAIL UP TO
THE SIZE OF GOLF BALLS THE MAIN THREATS. HOWEVER...ISOLATED
TORNADOES ARE ALSO POSSIBLE LATE THIS AFTERNOON AND EARLY THIS EVENING.
WIDESPREAD HEAVY RAINFALL TONIGHT COULD LEAD TO MINOR TO MODERATE
MAINSTEM RIVER AND TRIBUTARY FLOODING...AND POSSIBLY LOCALIZED
FLASH FLOODING. THE GREATEST FLOOD POTENTIAL WOULD BE SOUTH AND
EAST OF DES MOINES INCLUDING THE LOWER SKUNK AND IOWA RIVER
BASINS...AS WELL AS THE DES MOINES RIVER BASIN BELOW SAYLORVILLE
RESERVOIR.

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

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THUNDERSTORMS ARE LIKELY MONDAY MORNING BUT WILL END BY AFTERNOON.
ADDITIONAL HEAVY RAIN IS POSSIBLE EARLY MONDAY WHICH WILL CONTINUE
TO POSE A FLOODING THREAT. THE FLASH FLOOD WATCH IS IN EFFECT FOR THE
AREA UNTIL 10 AM MONDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED TODAY AND TONIGHT.

MOYER

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
117 PM CDT SUN APR 26 2009

IAZ070-071-081-261845-
ADAIR-ADAMS-CASS-
117 PM CDT SUN APR 26 2009

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN CASS...SOUTHWESTERN
ADAIR AND WESTERN ADAMS COUNTIES UNTIL 145 PM CDT...

AT 114 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM NEAR VILLISCA...OR 80 MILES SOUTHWEST OF DES
MOINES...MOVING NORTHEAST AT 50 MPH.

PENNY SIZE HAIL IS EXPECTED WITH THIS STORM.

THIS STORM WILL BE NEAR...
  CARBON BY 125 PM CDT.
  CUMBERLAND AND BRIDGEWATER BY 140 PM CDT.

THE TOWNS OF NODAWAY AND MASSENA ARE ALSO IN THE PATH OF THIS STORM.

JUNGLUTH