29 APRIL 2010 EXTENDED FORECAST

POWESHIEK COUNTY, IOWA (WEATHER)

29 APRIL 2010 EXTENDED FORECAST

A LOW PRESSURE IN NEBRASKA IS EXPECTED TO MOVE NORTHEAST OVER MINNESOTA LATER TODAY...MOISTURE WILL BEGIN
TO ARRIVE TONIGHT WITH SHOWERS AND THUNDERSTORMS FORMING ALONG A FRONTAL BOUNDARY IN WESTERN IOWA THROUGH NORTHEASTERN KANSAS. SOME STORMS COULD BE SEVERE AND LAST THROUGH TOMORROW AS THE FRONTAL BOUNDARY REMAINS OVER THE UPPER MIDWEST. SHOWER ACTIVITY WILL BEGIN TO DIMINISH EARLY SATURDAY MORNING... THEN RETURN AGAIN LATE SATURDAY AFTERNOON.

VERY WINDY THIS AFTERNOON (SOUTH GUSTS TO 40/45MPH)...........WHILE THE THUNDERSTORM THREAT REMAINS THE SAME, THE "SEVERE" THREAT IS ABIT LESS OMINOUS THAN IT HAS THRU THE WEEK - BUT THE THREAT STILL REMAINS.......EXPECT THUNDERSTORM DEVELOPMENT FROM WEST TO EAST THIS AFTERNOON THRU MIDNITE. THE LEADING EDGE WILL BE IN POW CTY MIDNITE - 2AM WITH A RATHER SLOW MOVING FINE LINE (ABOUT 50 MILES WIDE) OF HEAVY RAINFALL BEHIND THE LEADING EDGE. EXPECT HEAVY PRECIP TO MOVE THRU BETWEEN 4AM AND 8AM FRIDAY MORNING - WITH PERSISTING SHOWERS AND THUNDERSTORMS THRU THE DAY FRIDAY - WITH ISOLATED SEVERE/STRONG THUNDERSTORMS FROM POW CTY EASTWARD FRIDAY AFTERNOON............

SEVERE THUNDERSTORM THREAT THIS AFTERNOON: 50 MILES EITHER SIDE OF A LINE FROM MANKATO MN., TO PERRY IOWA, TO CLARINDA IOWA - EASTERN BOUNDARY INCLUDES DES MOINES........

SEVERE THUNDERSTORM THREAT TONITE INTO FRIDAY MORNING: 50 MILES EITHER SIDE OF A LINE FROM DECORAH TO GRINNELL TO LAMONI...........

TODAY AND FRIDAY 29TH/30TH - WINDY - STRONG THUNDERSTORMS DEVELOPING LATE THIS EVENING (AROUND MIDNITE) WITH HEAVIER RAINFALL (1+ INCH) OVERNITE INTO MID DAY FRIDAY - THEN ISOLATED SHOWERS/THUNDER (ISOLATED SEVERE POW CTY AND EASTWARD) THE REMAINDER OF FRIDAY - TEMP 75/70

SAT THRU MONDAY MAY 1ST-3RD - WINDY - PARTLY CLOUDY BCMG CLOUDY WITH SHOWERS AND THUNDERSTORMS BY AFTERNOON SATURDAY AND LASTING THRU MONDAY - TEMPS LOW 70'S

TUESDAY AND WED 4TH/5TH - EVENING ISOLATED SHOWERS/THUNDERSTORMS ENDING OVERNITE WED - COOLER WITH GUSTY NORTH WINDS

THURSDAY 6TH - PARTLY CLOUDY

FRIDAY AND SAT 7TH/8TH - INCREASING CLOUDS WITH SHOWERS AND THUNDERSTORMS