Iowa Environmental Mesonet Daily Bulletin for 18 August 2017

News

No news is good news

IEM Code Development on Github

Daily Feature

Muted August Range
Date: 17 Aug 05:29 AM
Votes: Good: 8   Bad: 1 Abstain: 0

The featured chart displays the range between the warmest high and coldest low for each August on record for Des Moines. The top panel displays the range between the two temperatures and the bottom panel shows the magnitude. The bar lines are the averages. It is kind of interesting to see that the recent year's August have almost all had below average range in temperature. Rewording, the range between the warmest high and coldest low is becoming less. One theory for this could be elevated humidity levels acting to keep overnight lows warmer and daytime highs cooler. The current forecast looks to continue the muted range with nothing too hot nor cold.

NWS Watch/Warning Summary for 12 AM 17 Aug 2017 - 12 AM 18 Aug 2017 CDT

Summary By WFO Watches
Type USIA ARXDVNDMXOAXFSD US
Tornado 4 0 0 0 0 0 0 0
Svr Tstorm 50 0 0 0 0 0 0 0
Flash Flood 10 0 0 0 0 0 0---

ARX = LaCrosse, WI DVN = Davenport, IA DMX = Des Moines, IA OAX = Omaha, NE FSD = Sioux Falls, SD

IEM Cow Report

SVR+TOR Warnings Issued: 51 Verified: 13  [25.5 %]
Reduction of Size Versus County Based     [75.9 %]
Average Perimeter Ratio                   [27.8 %]
Percentage of Warned Area Verified (15km) [11.8 %]
Average Storm Based Warning Size          [1205 sq km]
Probability of Detection(higher is better)[0.44]
False Alarm Ratio (lower is better)       [0.75]
Critical Success Index (higher is better) [0.19]