Wednesday & Thursday Thunderstorms

A cold front that is currently creating thunderstorms over the Dakotas will continue to move eastward through the nighttime hours. A few of these thunderstorms, or showers, may reach northwest Iowa by sunrise tomorrow. Although these showers and storms may not last too long beyond sunrise, their cloud cover is likely to stick just ahead of the front for a good portion of the morning. However, further ahead of the front and potentially along the front, clear(ing) skies should occur to allow the warm-up into the 80s over the state for highs.

This clearing along with increase in overall moisture with southerly winds, should allow for moderate instability ahead of the front in western and central Iowa. With continued frontal forcing, and some enhanced lift due to positive vorticity advection, thunderstorms do appear on the probable side. Although there are some negatives to the development of storms, it does appear that there will be sufficient moisture, instability, and lift to produce the storms. The severe threat with these storms appears limited by the lack of sufficient shear. Multicell clusters, or possible lines of storms along the front appear to be the main storm mode that could occur tomorrow. A few of the storms may be able to produce gusty winds, and some marginally severe hail during the late afternoon and evening hours.

Overnight lows on Wednesday should range from the mid 50s in northwest Iowa, to lower to mid 60s across the rest of the state. Showers and thunderstorms chances are in the forecast for all but extreme northwest Iowa. Lingering showers and thunderstorms are possible Thursday morning along the I35 corridor, with these chances shifting to the eastern third of the state by late afternoon. The severe weather chances once again seem quite low with the lack of overall instability, shear, and good lifting, along with others. Highs Thursday should be in the lower to mid 80s across the state; with overnight lows in the 50s across a majority of the state, a few low 60s are possible in southeast Iowa where the front is just moving through.