May is an active month for severe weather in Iowa. The featured chart presents the number of county based warnings issued in Iowa by day of May for each year since 1986. The beginning of May this year certainly started off active with severe weather each day, but has recently been very quiet. Humidity values have been on the dry side recently, which among other factors have prevented storms from developing over the past week. Thunderstorms are an important part of our climate as they bring a majority of the yearly rainfall to the state, so we have to take the good (needed rainfall) with the bad (severe weather).

Voting:
Good = 34
Bad = 5

Tags:   may  

This past Sunday and Monday saw high temperatures over 90 for most of the state and lows around 70. For May, these two days were some of the warmest on record and the warmest for days prior to 25 May as shown by the featured illustration. The two days were also exceptional for having low temperatures above 70, which was only the sixth time that has happened in May dating back to 1893. All of these values are statewide areal averages computed by the IEM.

Voting:
Good = 19
Bad = 6

Tags:   may10   may  

The abnormally cool stretch of weather ended up lasting a full week for Ames with high temperatures not reaching 60 degrees. According to IEM data, this sets a record for consecutive days below 60 in May. The featured chart displays the monthly records for Ames and the most recent year the record was set or tied. During the winter months, a large number of years had the entire month below 60. It is interesting to see that July never has had a high temperature below 60 for Ames since 1893. Temperatures will approach 70 today!

Voting:
Good = 48
Bad = 8

Tags:   may10   highs   may  

It was just on Tuesday that high temperatures soared into the 80s here in Ames. The featured chart looks at the observed frequencies of high temperatures above 80 and below 60 after a day with a high above 80. The climatological occurrence of having a sub 60 and above 80 day in May is shown as well (flat lines). With forecasted highs on Friday and Saturday in the 50s (day 3 and day 4), the chart would indicate this is rather rare. Our average highs are in the upper 60s, so we will be well below normal with some locations struggling to even reach 50 on Saturday.

Voting:
Good = 67
Bad = 14

Tags:   may