First Tornadoes of 2015 in Iowa

A triple point set up spawned Iowa’s first confirmed tornadoes of the 2015 severe weather season on April 9th.

I was unable to chase this day, as I had other commitments. But that didn’t stop me from keeping an eye on the situation as it progressed across the state during the middle portion of the day.

A low pressure area was dragging a cold front across the state as well as lifting a warm front north covering the SE portion of Iowa. Temps on the west side were in the 40-50’s, while SE IA basked in the 60’s. The SPC’s 1300z outlook had Eastern Iowa in the “slight” category, which would later be upped to the  “Enhanced Category”.  A 5% tornado probability was out for the area as well.

day1otlk_20150409_1300_prtday1probotlk_20150409_1300_torn_prt

Initiation commenced in early afternoon in far southern Iowa along I-35. At first the storms seemed to have difficulty holding their own as conditions just weren’t quite where they needed to be.

Things finally came together and the cells become tornadic with the 1st tornado report coming in at 517pm CST near the town of Donahue in Scott County, Iowa. A 2nd tornado was reported at 546pm near Clinton, Iowa from the same storm.

NWSFO KDVN (Quad Cities) sent out a team to survey the area and found the 1st tornado had in fact been on the ground for approx 22 miles! Their prelim storm report is below:

…NWS DAMAGE SURVEY RESULTS FOR 04/09/15 TORNADOES…

.TORNADO #1 …

RATING: EF-1
ESTIMATED PEAK WIND: 100 MPH
PATH LENGTH /STATUTE/: 22 MILES
PATH WIDTH /MAXIMUM/: 100 YARDS
FATALITIES: 0
INJURIES: 0

START DATE: 04/09/2015
START TIME: 5:04 PM CDT
START LOCATION: 8 MILES WEST OF MAYSVILLE IOWA
START LAT/LON: 41.6510/-90.8766

END DATE: 04/09/2015
END TIME: 5:30 PM CDT
END LOCATION: 2 MILES SOUTH OF DEWITT IOWA
END LAT/LON: 41.7966/-90.5384

STORM SURVEY REVEALED DAMAGE PRIMARILY TO FARM OUTBUILDINGS AND TREES.

.TORNADO #2…

RATING: EF-1
ESTIMATED PEAK WIND: 100 MPH
PATH LENGTH /STATUTE/: 13 MILES
PATH WIDTH /MAXIMUM/: 75 YARDS
FATALITIES: 0
INJURIES: 0

START DATE: 04/09/2015
START TIME: 5:40 PM CDT
START LOCATION: 1 MILE SOUTHEAST OF CLINTON AIRPORT
START LAT/LON: 41.8152/-90.0644

END DATE: 04/09/2015
END TIME: 6:00 PM CDT
END LOCATION: 5 MILES NORTHEAST OF FULTON IL
END LAT/LON: 41.9154/-90.0644

STORM SURVEY REVEALED DAMAGE PRIMARILY TO FARM OUTBUILDINGS AND TREES.

Posted below is an animation of the cells as they moved through Eastern Iowa.  (Click for larger version)

9apr2015radar

This entry was posted in General Weather.