Wednesday, May 2, 2012

Severe Risk on Friday Will Complete The '3 Days of Rain'

There is a severe weather risk for the Midwest and eastern Plains into the middle Great Lakes for Friday, May 4th.

A boundary of sorts looks to set up in the area outlined. It does appear that instability will be high in the highlighted area, giving storms a very well developed breeding ground. A sharp lake breeze from Lake Michigan in a southwest direction may very well feed into this instability and ignite some intense thunderstorms. A wind field that will be going opposite directions on different sides of this boundary is making me concerned for some rotation. However, considering that the major shearing and upper level wind dynamics are farther north, tornadoes will not be a huge concern.

In southwest Texas, another boundary may ignite some intense storms. This would likely be along a traditional dry line, which would incite the potential for some rotation. That remains to be seen in the long term.

Day 2 Slight Risk Nearly Spans Border-to-Border

Overall Risk

Probability of any severe weather
There is a slight risk of severe weather for tomorrow, and it spans nearly from border to border.

Tomorrow, high instability combined with humid air and high temperatures will make for a potentially intense day in northern Illinois, southern Michigan, and eastern Iowa.
Current indications are that isolated storms will pop up and quickly transition to clusters of storm systems that will be sweeping the area. The clusters may have the most impact on the 30% and hatched areas. For future reference, a hatched area represents a 10% chance of a 'significant' severe weather occurrence (large hail, extreme winds, etc.).

I am within this slight risk area and will try to get pictures if I am able to.


Damaging Wind Threat Sparks Moderate Risk Issued for Today, May 2

Overall Risk

Hail Risk

Tornado Risk

Damaging Wind Risk
A moderate risk of severe weather has been issued for eastern Nebraska, western Iowa today as a slight risk of severe weather spans half of the country.

This moderate risk has been issued on account of an elevated damaging wind threat. It does appear that supercells will evolve into a cluster of storms. It can be expected that these storms will be intense and may have powerful downdrafts (a flow of storm-cooled air from the storm- the opposite of an updraft) that could cause damage.
Because of the proximity to the low pressure center, as well as the frontal boundary, there is a tornado threat for the 30% area today. It is somewhat elevated, so a brief spin-up is possible in areas in the 5% tornado graphic.
Farther out to the east, strong showers and storms will develop and become several clusters that will be roaming the area. No significant severe weather is expected, but some small hail and gusty winds are possible.