Iowa Environmental Mesonet Daily Bulletin for 21 August 2018


No news is good news

IEM Code Pushes <to branch> on Github

Daily Feature

August Winds
Date: 20 Aug 05:34 AM
Votes: Good: 8   Bad: 0 Abstain: 0

The featured chart displays a simple hourly averaged wind speed by month for Ames. The month of August shows up as the lowest value for just about every hour of the day. The light winds are one of the reasons the summer heat can feel the most oppressive during this month. Winds on Sunday were generally light over the state, but will be on the increase for Monday with a passing storm system. There are many interesting climatology features shown by this chart including a clear diurnal signal as solar heating of the ground drives vertical mixing of the air, which mixes down higher speed air aloft to the surface.

NWS Watch/Warning Summary for 12 AM 20 Aug 2018 - 12 AM 21 Aug 2018 CDT

Summary By WFO Watches
Tornado 7 1 0 1 0 0 0 0
Svr Tstorm 73 0 0 0 0 0 0 2
Flash Flood 18 0 0 0 0 3 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: 80 Verified: 18  [22.5 %]
Reduction of Size Versus County Based     [82.7 %]
Average Perimeter Ratio                   [29.8 %]
Percentage of Warned Area Verified (15km) [10.9 %]
Average Storm Based Warning Size          [1206 sq km]
Probability of Detection(higher is better)[0.61]
False Alarm Ratio (lower is better)       [0.78]
Critical Success Index (higher is better) [0.20]