Monday morning update

Another decent storm system for the Ohio Valley. Energy from this system continues to be further and further south as easc model run has been coming out since late last week. Latest 12Z runs now have the lead H5 short/vort max passing virtually on top of us tomorrow morning !!
This , of course, also means that the sfc low with this system is passing much farther south and also pretty much right over our area late tonight / tomorrow morning.

Models also suggest a good slug of moisture in here tonight/tomorrow. As sfc low/triple point pass through the region, there could be a narrow ribbon of weak instability passing through...check out the MLCAPE from last night's 00Z GFS.

This weak instability combined with good dynamic forcing means a good round of showers with even some thunder embedded within.
System shifts northeast tomorrow morning. Strong CAA throughout day sends temperatures below critical by late morning as a changeover to snow takes place. This is where things get a little interesting and some model divergence takes place. NAM still has a big area of 90% + wrap around moisture shifting through the region along with decent lift. This deep moisture extends all the way down to the TN/MS-AL line !! This wrap-around moisture looks overdone/too far south considering the wave/H5 energy is 1) not closed off, 2) accelerating towards a confluent flow, 3) moving northeast. In this pattern, the wrap around / def zone is north / northwest of the H5 vort and should be shifting NE with the vort - NOT expanding and moving due east / moving southeast as the NAM has it. GFS 12Z model data looks better with it's placement / moisture pattern during the day Tuesday.

Having said all this... sensible weather-wise, rain changes to snow tomorrow with periods of light snow and flurries tomorrow late/morning into tomorrow night - with even some flurries lingering into Wednesday morning. Accumulations look to be quite light and mainly on grassy areas during the day Tuesday. Up to an inch or two possible in the far northern counties of the viewing area with amounts diminishing as you shift south towards the Ohio river into Kentucky.

Real cold air should arrive tomorrow night as 2nd H5 shortwave shifts south through the mean trough over the region. H85 temps drop from -15 to -18C behind this secondary wave. In addition, NAM still showing levels saturated (i.e. H9 & H85) into Wednesday morning in the good ice crystal (dentrite) layer. Bottomline - a wintry Wednesday expected with flurries, blustery conditions and temps likely holding in the 20s for highs !! Ouch.

Another Update tonight gang..

Have a great Day

Later:
Jay