Severe Thunderstorm Warning 39, NWS Des Moines, IA

IAZ004>006-015-016-023>025-033>036-044>047-057>059-070>072-081>083-
092>094-151700-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
532 AM CDT FRI MAY 15 1998

HAZARD NUMEROUS THUNDERSTORMS.  SOME OF THE STORMS MAY BE SEVERE WITH
WIND GUSTS UP TO 70 MPH AND HAIL 3/4 INCH OR LARGER IN DIAMETER.

AREA OF CONCERN ALL OF CENTRAL IOWA WILL BE AFFECTED.  THE GREATEST
THREAT WILL BE THAT AREA EAST OF A MASON CITY TO OTTUMWA LINE.

TIMING DETAILS WESTERN IOWA WILL BEGIN TO BE AFFECTED BY 900 AM THIS
MORNING WITH THE STORMS SPREADING EAST DURING THE DAY.  THEY SHOULD
REACH THE CENTRAL SECTIONS OF THE STATE BY SHORTLY AFTER NOON AND
EASTERN IOWA BY 400 PM.  THE STORMS WILL END BY LATE AFTERNOON OVER
WESTERN INTO CENTRAL IOWA...AND BY MID EVENING OVER EASTERN SECTIONS.

METEOROLOGICAL COMMENTS A VERY UNSTABLE AIRMASS REMAINS IN PLACE OVER
IOWA.  THE AIRMASS HAS BEEN CAPPED OVERNIGHT WITH TEMPERATURES AT 700
MB /AROUND 10000 FEET/ ABOVE 12 DEGREES C.  THIS CAP IS EXPECTED TO
ERODE DURING THE DAY TODAY AS COOLER AIR MOVES IN ALOFT.  SEVERAL
FACTORS WILL COME TOGETHER TO ENHANCE THUNDERSTORM DEVELOPMENT TODAY.
A COLD FRONT OVER CENTRAL NEBRASKA WILL ADVANCE EAST TODAY AND BE IN
WESTERN IOWA BY LATE THIS AFTERNOON...CENTRAL SECTIONS BY
SUNSET...AND EASTERN IOWA BEFORE MIDNIGHT.  IN ADDITION AN
UNSEASONABLY STRONG UPPER LEVEL SYSTEM LOCATED OVER THE TEXAS
PANHANDLE THIS MORNING WILL LIFT NORTHEAST RAPIDLY INTO SOUTHWEST
IOWA BY THIS EVENING.  ALTHOUGH THERE WILL BE A LOT OF CLOUDINESS
AROUND TODAY...ENOUGH SUNSHINE WILL GET THROUGH TO PUSH TEMPERATURES
INTO THE LOW TO MID 80S IN MOST AREAS.  DEW POINT TEMPERATURES HAD
REACHED THE LOW 70S OVER SOUTHWEST AND WEST CENTRAL IOWA...WITH MID
60S FARTHER EAST.  SINCE CONVECTION IS EXPECTED TO TAKE PLACE
RELATIVELY EARLY OVER WESTERN IOWA...THE THREAT OF SEVERE WEATHER
WILL BE REDUCED.  OPTIMUM TIMING FOR THUNDERSTORM DEVELOPMENT OVER
THE EAST MAKES THE LIKELIHOOD OF SEVERE WEATHER HIGHER THERE.

PRECAUTIONS--STAY TUNED TO NOAA WEATHER RADIO...COMMERCIAL TELEVISION
OR RADIO STATIONS...OR YOUR CABLE TELEVISION PROVIDER FOR LATER
STATEMENTS CONCERNING THE THUNDERSTORM THREAT.  THE NEXT STATEMENT
WILL BE ISSUED AROUND 1100 AM THIS MORNING.

IAZ004>006-015-016-023>025-033>036-044>047-057>059-070>072-081>083-
092>094-151700-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
532 AM CDT FRI MAY 15 1998

HAZARD NUMEROUS THUNDERSTORMS.  SOME OF THE STORMS MAY BE SEVERE WITH
WIND GUSTS UP TO 70 MPH AND HAIL 3/4 INCH OR LARGER IN DIAMETER.

AREA OF CONCERN ALL OF CENTRAL IOWA WILL BE AFFECTED.  THE GREATEST
THREAT WILL BE THAT AREA EAST OF A MASON CITY TO OTTUMWA LINE.

TIMING DETAILS WESTERN IOWA WILL BEGIN TO BE AFFECTED BY 900 AM THIS
MORNING WITH THE STORMS SPREADING EAST DURING THE DAY.  THEY SHOULD
REACH THE CENTRAL SECTIONS OF THE STATE BY SHORTLY AFTER NOON AND
EASTERN IOWA BY 400 PM.  THE STORMS WILL END BY LATE AFTERNOON OVER
WESTERN INTO CENTRAL IOWA...AND BY MID EVENING OVER EASTERN SECTIONS.

METEOROLOGICAL COMMENTS A VERY UNSTABLE AIRMASS REMAINS IN PLACE OVER
IOWA.  THE AIRMASS HAS BEEN CAPPED OVERNIGHT WITH TEMPERATURES AT 700
MB /AROUND 10000 FEET/ ABOVE 12 DEGREES C.  THIS CAP IS EXPECTED TO
ERODE DURING THE DAY TODAY AS COOLER AIR MOVES IN ALOFT.  SEVERAL
FACTORS WILL COME TOGETHER TO ENHANCE THUNDERSTORM DEVELOPMENT TODAY.
A COLD FRONT OVER CENTRAL NEBRASKA WILL ADVANCE EAST TODAY AND BE IN
WESTERN IOWA BY LATE THIS AFTERNOON...CENTRAL SECTIONS BY
SUNSET...AND EASTERN IOWA BEFORE MIDNIGHT.  IN ADDITION AN
UNSEASONABLY STRONG UPPER LEVEL SYSTEM LOCATED OVER THE TEXAS
PANHANDLE THIS MORNING WILL LIFT NORTHEAST RAPIDLY INTO SOUTHWEST
IOWA BY THIS EVENING.  ALTHOUGH THERE WILL BE A LOT OF CLOUDINESS
AROUND TODAY...ENOUGH SUNSHINE WILL GET THROUGH TO PUSH TEMPERATURES
INTO THE LOW TO MID 80S IN MOST AREAS.  DEW POINT TEMPERATURES HAD
REACHED THE LOW 70S OVER SOUTHWEST AND WEST CENTRAL IOWA...WITH MID
60S FARTHER EAST.  SINCE CONVECTION IS EXPECTED TO TAKE PLACE
RELATIVELY EARLY OVER WESTERN IOWA...THE THREAT OF SEVERE WEATHER
WILL BE REDUCED.  OPTIMUM TIMING FOR THUNDERSTORM DEVELOPMENT OVER
THE EAST MAKES THE LIKELIHOOD OF SEVERE WEATHER HIGHER THERE.

PRECAUTIONS--STAY TUNED TO NOAA WEATHER RADIO...COMMERCIAL TELEVISION
OR RADIO STATIONS...OR YOUR CABLE TELEVISION PROVIDER FOR LATER
STATEMENTS CONCERNING THE THUNDERSTORM THREAT.  THE NEXT STATEMENT
WILL BE ISSUED AROUND 1100 AM THIS MORNING.

IAZ044>047-057>060-070>074-081>085-092>096-151632-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
832 AM CDT FRI MAY 15 1998

HAZARD--STRAIGHT-LINE DAMAGING WINDS OF 60 TO 70 MPH.  HAIL TO 3/4
INCH OR LARGER IS ALSO POSSIBLE.

TIMIMG DETAILS AND AREA OF CONCERN--
AREAS SOUTHWEST OF ATLANTIC TO MOUNT AYR FROM 900 TO 1030 AM
AREAS FURTHER NORTHEAST AFTER 1030 AM.

METEOROLOGICAL COMMENTS--A DAMAGING SQUALL LINE OF THUNDERSTORMS
WILL BE RACING NORTHEAST AT 65 MPH FROM SOUTHEAST NEBRASKA AND
NORTHWEST MISSOURI THIS MORNING.  THIS LINE HAS A LONG HISTORY OF
DAMAGING WINDS BACK INTO KANSAS.

PRECAUTIONS--SPOTTER GROUPS AND EMERGENCY MANAGEMENT SHOULD BEGIN
ACTIVATING OVER TAYLOR...ADAMS...CASS AND RINGGOLD COUNTIES SOON.
THEY WILL LIKELY BE NEEDED BY 900-1000 AM.  COUNTIES FURTHER
NORTHEAST MAY ALSO BE NEEDED BETWEEN 1000 AND NOON.  THIS IS A
POTENTIALLY DANGEROUS SITUATION WITH DAMAGING WINDS LIKELY.

KULA