Hello all, well it's looking like some busy times ahead for the Ohio Valley (as is often the case this time of year). Sevearl systems will affect us during the next week. The first arrives tomorrow (Saturday).
Saturday's system is a strong "clipper" type system that'll be passing north of us. There is a difference though with tomorrow's clipper from the majority of clippers that affect the Ohio Valley. Most clipper systems travel from northwest to southeast across the Ohio Valley. As a result of this movement, most (if not all) the decent precip (i.e. snow) is along and north of the sfc low track - with the best snows occurring along and north of the H5 system.
So let's look at tomorrow's system. the following maps are from the 12 Fri run of the NAM.
Folks, look how far north the H5 vort and sfc low are tracking !! At first glance you'd say "no way are we getting any snow" - and with "normal" clippers that would be correct ! Heck, sfc temps Saturday morning around here will go well into the 40s ! But this one is a bit different as far as its impacts are concerned for us. Look closer at the H5 charts again above especially the 30 & 36 hr panels. This system is bottoming out near Chicago ! In other words it is starting to track more northeasterly than the typical southeasterly movement that clippers usually have through the Ohio Valley. It's main jet streak is bottoming out and starting to shift to the eastern side of the H5 system - In other words, our area is getting on the RRQ of this upper streak providing us with good lift - and this is happening as the associated cold front in the low levels is passing through the region so we are getting strong low level CAA at this same period. Also, look at the additional energy on the back side of the trough. This second vort lobe is causing the entire system to slow some but is also inducing PVA (pos vort advection) across our region adding to the lift that the RRQ of the original jet streak is already providing and because of this secondary vort lobe, overunning moisture is occurring behind the cold front (i.e. over our region) resulting in a rapid increase to post frontal precipitation.
So.... sensible weather wise ..... light rain will likely develop across the area tomorrow late morning into the early afternoon. This rain however, will quickly change to wet snow and accumulate some - but mainly on grassy areas. At this time I like around 1 inch of wet snow (locally 2 inches in spots) for Saturday afternoon.
Cold air continues to spill into the Ohio Valley behind this system . Sunday looks to be a real cold day with temperatures just in the 20s to near 30 for a high with flurries and occasional snow showers continuing. Bottom line... a wintry weekend on the way.
Active weather pattern will continue next week especially for the Wednesday and Thursday time frame. A couple of systems will come at us again giving us milder weather but good rain chances, some which could be heavy mainly Thursday (including thunderstorms).
We'll keep you posted, in the meantime... have a great weeekend,
Jay
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