Wednesday storms and early week heat?

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1. Sunday saw regions across the south reach 80 with strong WAA. This gives me an indicator modeling is underdoing WAA. the ECMWF overall with my limited time using the full suite of model data has a better handle of WAA in my view so I will mainly use this for temps.

2. To start Monday the warm front will be north of our region but the far northern counties may be close enough to it for isolated showers and thunderstorms through Tuesday. Morning temperatures will be in the mid to upper 50’s with highs once again from the mid 70’s to low 80’s with slightly cooler values for the far north. The same temperature spread should hold for Tuesday. Both days will feature stong southerly winds ahead of the next front and low pressure.

3. Wednesday the warm front will extend from the great lakes to northeast this means a nice snow event from isentropic lift/ overrunning with decent forcing could impact travel plans to Newark later this week for the CATS. In fact this region could be on the rain/snow/ice line for a fairly large winter storm tracking from the upper plains to upper midwest to northeast. However it’s the end of march we should be discussing severe weather!

The cold front will sweep through Wednesday night ahead of this front I think parameters are favorable for a squall line of thunderstorms to form. Storms should be fueled by ample moisture ( dewpoints over 60*F) some shear though not nearly as much as our winter events and an unstable enviroment just passed the marginal threshold.  Also the next few days will mainly deal with where the line will develop and the overall timing of the line.  Gusty winds will be the main threat with scattered wind gusts from 40-80 mph. I fully expect a watch and a few warnings Wednesday afternoon and evening for the region. Right now I’m favoring northern KY as having the best chance for a nasty squall line, here’s why.

instabilty region ( NAM) -2 marginal, -6 unstable  If you have accuweather pro this really allows you to visualize the regions between sites with sounding data.

 Loading Maps...

This shows a region around LOU where instability is present for storm formation, in addition steep lapse rates ( temp difference w/height) and the front which will lift the air ahead of it should allow for thunderstorm formation Wednesday afternoon over southern ILL/IND which then should translate southeast into our region by late afternoon.

shear region

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notice the region of best shear is well to our northeast along the warm front, that is why the triple point is always a good place to be for severe weather. values of 100 or so as indicated do not show a threat for rotation with any thunderstorms. Thus we’re looking at a wind damage threat from a squall line along a cold front Wednesday afternoon and night. Also of note is the NAM model shown likes to overdo instability a bit. Wednesday will be the last day with highs in the 70’s.

We clear out slowly Thursday with highs in the 50’s and lows in the 30’s as nw flow takes over this keeps us chilly into next weekend. the NAO shows a tank into late month However i suspect we will only be seasonably cool.

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2 Responses to “Wednesday storms and early week heat?”

  1. mitchg Says:

    12z NAM really ramping up severe threat.

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