Saturday, March 27, 2010

Storms Possible Tonight

The Storm Prediction Center has included parts of southeast Missouri and northeast Arkansas in their "Slight Risk" area for severe thunderstorms on their latest Day 1 Outlook.

SPC forecasters mention in their discussion that the biggest risk will be damaging wind within a line of thunderstorms pushing towards the Mississippi River later this evening/tonight.

Here is the probabilistic graphic for damaging winds put out by the SPC.

What that means is that there is a 15% chance of damaging wind (in excess of 58mph) within 25 miles of any point within the blue area.

As previously mentioned we are still a little moisture starved. Dew points this morning are only in the 30°'s. Winds this morning are out of the southeast so we can look to see what dew points are like to our east to see what kind of moisture there is to tap in to. Dew points are in the middle 30°'s down across central Tennessee. Eventually we will see our winds turn around to the south this afternoon and start to draw up moisture from the Gulf of Mexico. The question is how much moisture.

Last night's run of the forecast models are trying to draw in more moisture. Here is a look at the NAM model's run of the dew point forecast for later this afternoon.

You can see how the model brings an axis of 50° dew points up through eastern Arkansas, the Missouri Bootheel, and southeast Missouri. I think we need to see our dew points at least in the lower 50°'s to sustain big thunderstorms.

Finally, here is a look at the NAM's depiction of what the radar might look like at 1am CT Sunday morning.

You can see how the model tries to bring the line of storms to the Mississippi River by 1:00am CT.

If you have recently purchased a NOAA Weather Radio you might get a chance this evening to test it out if a watch or warning is issued for your county. Stay tuned...

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