Saturday, April 9, 2011

Severe Storm Occurring in Iowa/Minnesota (April 9)

Severe storms are currently occurring in Iowa, moving into Minnesota.
Many tornado reports have been generated, indicating that these storms are supercells.
If you live Northeast and/or North of North Iowa, be prepared for potential extreme severe weather.


After a live radio briefing from the National Weather Service and an update from the Storm Prediction Center, this blog will be going into Severe Weather mode beginning 12pm CDT tomorrow.


The moderate risk for severe storms was moved south in response to an increased tornado threat.
Current thinking is that the storms will evolve as supercells, thus raising tornado potential and lowering damaging wind potential.
This is a very intense situation that this blog will be working to continue to update you on.

IMMEDIATE BROADCAST: April 10 Significant Severe Weather Outbreak

The Storm Prediction Center is saying "An upgrade to high risk appears likely across a portion of the Upper MS Valley in later outlooks."

At this time, anyone who is in the moderate risk RIGHT NOW in the image above should make IMMEDIATE preparations for an intense severe weather outbreak tomorrow afternoon into the evening.
With the high risk area expected, it can also be expected that:
1. The moderate risk area is expanded.
2. Threat risks go higher.

Above is the probability of severe weather within 25 miles of your home. The hatched (dashed) area in light blue is a 10% chance of significant severe weather (Hail 2 inches< , F2+ tornadoes) within 25 miles of your house.

The Weather Centre will be issuing updates as needed.

IMMEDIATE BROADCAST: April 9 Severe Weather

The Storm Prediction Center has updated the Upper Midwest severe weather outlook to MODERATE in some areas.
This comes as a low pressure ejects from the Rockies.
The first image is for the overall risk. As we can see, there is a pronounced risk of Moderate Risk area over the Plains into Upper Midwest region. The question is, what caused this?
The answer is, the risk of hail in the image above. With hail risk at 45% that is when Moderate Risk areas are introduced. Moderate areas can be introduced by combining parameters, but it looks like hail was the instigator.
The next image we will view is the tornado risk.
We can see the tornado risk isn't very high except for, again the Northern Plains into the Upper Midwest. However, that threat, though high, is localized, which is good for the welfare of the general public as well as storm chasers.
Judging by the threat above, it seems possible that a small squall line could begin to develop leading into tomorrow.
The last image is the damaging wind threat. This is one where the Moderate Risk area was left out. Instead, the primary threat settled over the Appalachians heading towards the Eastern Seaboard.

All in all, it appears that there will be a threat for some strong severe weather in the Northern Plains east into the Upper Midwest, with the primary threat being hail with localized tornado threats.