Severe Thunderstorm Warning 85, NWS Des Moines, IA

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-080300-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
525 PM CDT MON JUL 7 1997

HAZARD -- ISOLATED SEVERE STORMS. A TORNADO WATCH IS IN EFFECT UNTIL
1000 PM FOR AREAS NORTH OF HIGHWAY 30 AND WEST OF I-35 WITH A NEW
TORNADO WATCH IN EFFECT FROM DES MOINES WEST AND SOUTHWEST UNTIL
MIDNIGHT.  THE EVENING THREAT WILL BE ISOLATED LARGE HAIL AND DAMAGING
WINDS TO 70 MPH...WITH TORNADOES ALSO POSSIBLE. BY THE OVERNIGHT HOURS
THE PRIMARY CONCERN WILL BE GUSTY WINDS AND HEAVY DOWNPOURS.

TIMING AND AREA OF CONCERN -- THUNDERSTORMS CURRENTLY OVER SOUTH
DAKOTA...NEBRASKA AND EXTREME NORTHWEST IOWA WILL REACH AN ALGONA TO
FORT DODGE TO AUDUBON LINE BETWEEN 700 AND 800 PM.  STORMS SHOULD NOT
REACH CENTRAL IOWA UNTIL AFTER 800 PM...INCLUDING MASON CITY AND DES
MOINES. AFTER 1000 PM STORMS ARE EXPECTED TO APPROACH WATERLOO AND
EVENTUALLY OTTUMWA.

METEOROLOGICAL COMMENTS --  SEVERE THUNDERSTORMS DEVELOPED AROUND 400
PM FROM SIOUX FALLS INTO NORTHEAST NEBRASKA PRODUCING HAIL IN EXCESS
OF 1 INCH IN DIAMETER AND TORNADOES JUST WEST OF THE IOWA BORDER. THE
STORMS ARE NEAR THE INTERSECTION OF A WARM FROM WHICH EXTENDS INTO
SOUTHEAST IOWA AND A COLD FRONT WHICH EXTENDS INTO NORTHWEST KANSAS.
INTENSE THUNDERSTORMS ARE EXPECTED TO BUILD EASTWARD AND SOUTHWARD
ALONG THESE FRONTAL BOUNDARIES AS THE EVENING PROGRESSES.

THE ATMOSPHERE HAS BECOME VERY UNSTABLE ALONG THE MISSOURI RIVER WITH
LIFTED INDICES TO MINUS 8. SOUTHERLY SURFACE WINDS OF 25 MPH WERE ALSO
FEEDING THE STORMS. THESE FACTORS AND A VEERING VERTICAL WIND PROFILE
FAVOR SEVERE THUNDERSTORMS AND ISOLATED SUPERCELLS OVER THE WESTERN
THIRD OF IOWA. THE SEVERE THREAT SHOULD LESSEN AS THE STORMS MOVE EAST
OF I-35 AFTER 1000 PM...SINCE THE ATMOSPHERE IS NOT QUITE AS UNSTABLE
OVER THE NORTHEAST HALF OF IOWA. HOWEVER...TEMPERATURES AND DEW POINTS
ARE STILL RECOVERING STATEWIDE SO TRENDS WILL BE WATCHED CLOSELY. ALL
STORMS MOVING ACROSS IOWA WILL HAVE THE POTENTIAL FOR INTENSE
DOWNPOURS...BUT SHORT DURATION SHOULD LIMIT RAINFALL AMOUNTS.

PRECAUTIONS -- SPOTTER ACTIVATION WILL BE REQUIRED BETWEEN 600 AND 800
PM OVER COUNTIES NORTH OF HIGHWAY 30 AND WEST OF HIGHWAY 69. SPOTTERS
MAY ALSO BE NEEDED OVER NORTH CENTRAL...WEST CENTRAL AND SOUTHWEST
IOWA AFTER 800 PM. SEVERE WEATHER WATCHES MAY ALSO BE EXTENDED FARTHER
EAST THIS EVENING. MONITOR THUNDERSTORM OUTLOOKS AND SHORT TERM
FORECASTS FOR UPDATED INFORMATION.

JUNGBLUTH

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-080300-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
525 PM CDT MON JUL 7 1997

HAZARD -- ISOLATED SEVERE STORMS. A TORNADO WATCH IS IN EFFECT UNTIL
1000 PM FOR AREAS NORTH OF HIGHWAY 30 AND WEST OF I-35 WITH A NEW
TORNADO WATCH IN EFFECT FROM DES MOINES WEST AND SOUTHWEST UNTIL
MIDNIGHT.  THE EVENING THREAT WILL BE ISOLATED LARGE HAIL AND DAMAGING
WINDS TO 70 MPH...WITH TORNADOES ALSO POSSIBLE. BY THE OVERNIGHT HOURS
THE PRIMARY CONCERN WILL BE GUSTY WINDS AND HEAVY DOWNPOURS.

TIMING AND AREA OF CONCERN -- THUNDERSTORMS CURRENTLY OVER SOUTH
DAKOTA...NEBRASKA AND EXTREME NORTHWEST IOWA WILL REACH AN ALGONA TO
FORT DODGE TO AUDUBON LINE BETWEEN 700 AND 800 PM.  STORMS SHOULD NOT
REACH CENTRAL IOWA UNTIL AFTER 800 PM...INCLUDING MASON CITY AND DES
MOINES. AFTER 1000 PM STORMS ARE EXPECTED TO APPROACH WATERLOO AND
EVENTUALLY OTTUMWA.

METEOROLOGICAL COMMENTS --  SEVERE THUNDERSTORMS DEVELOPED AROUND 400
PM FROM SIOUX FALLS INTO NORTHEAST NEBRASKA PRODUCING HAIL IN EXCESS
OF 1 INCH IN DIAMETER AND TORNADOES JUST WEST OF THE IOWA BORDER. THE
STORMS ARE NEAR THE INTERSECTION OF A WARM FROM WHICH EXTENDS INTO
SOUTHEAST IOWA AND A COLD FRONT WHICH EXTENDS INTO NORTHWEST KANSAS.
INTENSE THUNDERSTORMS ARE EXPECTED TO BUILD EASTWARD AND SOUTHWARD
ALONG THESE FRONTAL BOUNDARIES AS THE EVENING PROGRESSES.

THE ATMOSPHERE HAS BECOME VERY UNSTABLE ALONG THE MISSOURI RIVER WITH
LIFTED INDICES TO MINUS 8. SOUTHERLY SURFACE WINDS OF 25 MPH WERE ALSO
FEEDING THE STORMS. THESE FACTORS AND A VEERING VERTICAL WIND PROFILE
FAVOR SEVERE THUNDERSTORMS AND ISOLATED SUPERCELLS OVER THE WESTERN
THIRD OF IOWA. THE SEVERE THREAT SHOULD LESSEN AS THE STORMS MOVE EAST
OF I-35 AFTER 1000 PM...SINCE THE ATMOSPHERE IS NOT QUITE AS UNSTABLE
OVER THE NORTHEAST HALF OF IOWA. HOWEVER...TEMPERATURES AND DEW POINTS
ARE STILL RECOVERING STATEWIDE SO TRENDS WILL BE WATCHED CLOSELY. ALL
STORMS MOVING ACROSS IOWA WILL HAVE THE POTENTIAL FOR INTENSE
DOWNPOURS...BUT SHORT DURATION SHOULD LIMIT RAINFALL AMOUNTS.

PRECAUTIONS -- SPOTTER ACTIVATION WILL BE REQUIRED BETWEEN 600 AND 800
PM OVER COUNTIES NORTH OF HIGHWAY 30 AND WEST OF HIGHWAY 69. SPOTTERS
MAY ALSO BE NEEDED OVER NORTH CENTRAL...WEST CENTRAL AND SOUTHWEST
IOWA AFTER 800 PM. SEVERE WEATHER WATCHES MAY ALSO BE EXTENDED FARTHER
EAST THIS EVENING. MONITOR THUNDERSTORM OUTLOOKS AND SHORT TERM
FORECASTS FOR UPDATED INFORMATION.

JUNGBLUTH

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-080300-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
836 PM CDT MON JUL 7 1997

HAZARD -- ISOLATED SEVERE STORMS. A TORNADO WATCH IS IN EFFECT UNTIL
1000 PM FOR AREAS NORTH OF HIGHWAY 30 AND WEST OF I-35 WITH A SECOND
TORNADO WATCH IN EFFECT FROM DES MOINES WEST AND SOUTHWEST UNTIL
MIDNIGHT.  HOWEVER...THE MAIN THREAT WILL BE ISOLATED LARGE HAIL AND
DAMAGING WINDS TO 65 MPH FOR THE REMAINDER OF THE EVENING. AFTER
MIDNIGHT THE PRIMARY CONCERN WILL BE GUSTY WINDS AND HEAVY DOWNPOURS.

TIMING AND AREA OF CONCERN -- A BROKEN LINE OF THUNDERSTORMS EXTENDING
FROM EAST OF ESTHERVILLE TO WEST OF STORM LAKE TO SOUTH OF SIOUX CITY
WILL CONTINUE TO MAKE STEADY EASTWARD PROGRESS. STRONGER STORMS ARE
LIKELY TO REACH MASON CITY AND FORT DODGE AROUND 1000 PM...WITH DES
MOINES...WATERLOO AND CRESTON NOT LIKELY TO SEE THUNDERSTORMS UNTIL
MIDNIGHT OR LATER. SHOWERS WILL PRECEDE THE MAIN THUNDERSTORM ACTIVITY
BY AND HOUR OR TWO OVER THE NORTHERN HALF OF IOWA.

METEOROLOGICAL COMMENTS --  MOST OF THE SEVERE WEATHER HAS BEEN
CONFINED TO NEBRASKA...WITH ISOLATED ONE INCH HAIL REPORTS AND VERY
WEAK TORNADOES IN FAR NORTHWESTERN IOWA. THE 700 PM RADIOSONDE DATA
SHOWED A 30 MPH LOW LEVEL JET AND INSTABILITY AXIS TO BE WEST OF THE
MISSOURI RIVER. AS THIS AXIS SHIFTS EASTWARD OVERNIGHT...THERE WILL BE
SUFFICIENT INFLOW AND CONVERGENCE FOR SCATTERED THUNDERSTORMS TO
CONTINUE PROGRESSING ACROSS IOWA. HOWEVER...THE TORNADO THREAT SHOULD
BE REDUCED BY 1000 PM AND ONLY A FEW OF THE STRONGEST STORMS ARE
LIKELY TO HAVE A HAIL AND DAMAGING WIND THREAT BY MIDNIGHT. VERTICAL
WIND SHEAR AND INSTABILITY ARE NOT STRONG ENOUGH TO SUSTAIN THE SEVERE
THREAT THROUGH THE NIGHT.

THUNDERSTORMS WILL CONTINUE TO PRODUCE 1 TO 2 INCHES OF RAIN IN AN
HOUR OVER ISOLATED LOCATIONS.

PRECAUTIONS -- SPOTTER ACTIVATION MAY BE REQUIRED UNTIL 1000 PM OR
MIDNIGHT IN LOCATIONS NORTH AND NORTHWEST OF DES MOINES. WATCH FOR
PONDING OF WATER ON ROADWAYS. MONITOR THUNDERSTORM OUTLOOKS AND SHORT
TERM FORECASTS FOR UPDATED INFORMATION.

JUNGBLUTH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
911 PM CDT MON JUL 07 1997

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

0845 PM    LAKOTA                    IA   1.25 INCH HAIL
07/07/97   KOSSUTH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
911 PM CDT MON JUL 07 1997

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

0845 PM    LAKOTA                    IA   1.25 INCH HAIL
07/07/97   KOSSUTH