Wednesday, February 23, 2011

Severe weather outlook for Thursday

The severe weather threat for the Mid-South continues for Thursday as models are merging towards an outcome that seems plausible.  One of the questions posed in recent MWN blog posts has been with regards to the placement of the low pressure system and warm front. It now appears that the warm front will move through the metro area completely, stalling to our north and placing much of the region in the "warm sector."  This is an area where Gulf moisture will flow freely into the region and atmospheric dynamics will be maximized ahead of the approaching low.  The low pressure center itself will pass by to our north, likely moving across northern AR and then into western KY.  Again, we'll be in a favorable quadrant of the low for severe weather. The only real remaining question is instability, which will go up if we get any sunshine tomorrow and be somewhat minimized if we get rain showers during the day.

For these reasons, the Storm Prediction Center has issued a somewhat rare "Moderate Risk" area that encompasses the tri-state for tomorrow.  According to the NWS, only about 10 times a year are moderate risk areas issued for Day 2.  The risk area is shown in the map below.  The second map shows the probability of severe weather within 25 miles of any one point, with the hatched area (over west TN, N MS, and AR) indicating a 10% chance or greater of "significant severe" weather within 25 miles of any point.  In other words, it appears our chance of seeing severe weather in the metro is about 50/50 (which is pretty high).



Thunderstorms are possible overnight tonight and early tomorrow as the warm front moves through the region from south to north, though these storms will stay below severe limits. A lull in the action is expected tomorrow morning and early afternoon before storms begin to fire to our west by mid-afternoon. I expect the greatest threat of severe weather, including tornadoes, to be between 5-10pm in the immediate area, earlier in east AR and later to our east.  Very heavy rain, damaging straight-line wind, large hail, and frequent lightning are all possible to probable as well.

To review severe weather safety rules, visit previous MWN blog articles on Severe Thunderstorms, Lightning, and Tornadoes. If you haven't already, form a severe weather plan with your family (including any children living at home) and share it with them.

MWN will have you covered during this potential severe weather event through all of our various means of communication, including the website, blog, Facebook, and Twitter.

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