With the SPC forecasting severe weather potential for southern Iowa and northern Missouri two days in advance, storm initiation finally began in western Iowa before noon on Wednesday, November 11, 2015.
Tornado Watch 535 was issued for much of eastern Iowa at 3:20 pm CST. A mix of strong CAPE, wind shear and warm air contributed to this unusual November severe event. The above image looks west at an advancing line of severe storms at 4:54 pm from Nutmeg Avenue at 220th Street (County Road G36), one mile east of Highway 1 in central Washington County, Iowa.
As the storm passed overhead, torrents of blinding rain made driving on 220th Street extremely difficult. We witnessed an SUV drive slowly off the road and into the ditch to the left, miraculously recover and pull back up to the road surface, only to slowly go off and into the ditch at right. A small parking oasis just before Highway 1 allowed us to pull into it to wait out the rain and hail. I could not see the hail clearly in the dark, but judging by the impacts on our vehicle estimated it to be penny size. The middle image--a video frame capture--shows a parked dump truck at 5:02 pm, which served as sort of a directional beacon which drew us to the safety of the fortuitous parking area.
This radar image graphic shows our position near the time of the middle image. Small hail cores can be seen in the area, colored in lavender. The early darkness of November made photographing the storm a challenge. Nikon D5000 DSLR camera.
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