First forecast on accumulations for Tuesday-Wednesday

A low pressure system is expected to develop along the gulf coast states and ride northeast into the southeastern United States. After highs in the 40’s today with drizzle and fog lows tonight will be in the 30’s followed by highs near 40 Tuesday with more clouds and drizzle. However by Tuesday night Low pressure comes northward developing a shield of precipitation on the backside. We will be northwest of the low track. in recent days there has been some speculation we may be to far west However as usual the track of storms like this one has shifted west over time as the modeling gets a better handle on storm strength.

The NAM model had convective feedback issues due to over development of thunderstorms in the gulf.  The GFS is coming west but is likley not quite west enough yet. My thinking lies with the ECMWF 12z run and the GFS ensemble mean which means around .5 of qpf into the region from Tuesday night to noon on Wednesday. With highs near 40 Tuesday temperatures may only cool into the mid 30’s by midnight. However thickness values and temperatures aloft are more supportive of snow once the precipitation starts. I expect a light rain to break out Tuesday evening this will change to snow around midnight through a process called dynamical cooling. My thinking is heavy precipitation rates will offset marginal thermal profiles for snow. Snow will be heavy at times early Wednesday morning with an expected accumulation of 2-4 inches of wet snow for Bowling Green. With temperatures near freezing roads may stay wet but heavy snowfall rates may make for slick travels. Snow should end by noon Wednesday with highs in the mid 30’s.

This snowfall forecast is largely dependent on several factors

– how much dynamical cooling occurs and how quickly

– track of the low I’m thinking owensboro 60 miles NW of us gets nothing and lake Cumberland 60 mi SE of us gets 6 or more inches. Any change in the track could lead to altered amounts. It should be noted any shifts are likely to be to the west.

– convective bands that may set-up thunderstorms could curl around the low center my thinking now is the best chance for any convective thundersnow is over lake Cumberland or further southeast. 

– downsloping flow off the apps which would limit qpf

Overall this forecast for 2-4 inches of wet snow early Wednesday has low to medium confidence.

MWG

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1 Response to First forecast on accumulations for Tuesday-Wednesday

  1. mitchell.gaines673 says:

    back to back gfs runs back me up with a cold rain going to 2 to perhaps 4 inches of snow in bowling green overnight Tuesday night. disagree with nws forecast calling for a dusting.

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