Risks today
1) Friday Twix Scale (keeping it at 2 bars for now)
2) Sunday night (freezing rain/sleet chance)
3) Feb 5 (snow chance)
LATEST ON FRIDAY
The issue remains on moisture content of this system ...as phasing will the decided factor. And that isn't looking likely. I think they will get close enough that we could see some light accumulations...but a full-blown winter storm is not in the cards with the two systems staying separate streams.
I will start with the GFS as it remains the most consistent with the pattern.
The BUFKIT profiles really show the story the best. A reminder...this is a tilted view of our atmosphere in Louisville from surface to just above airplane level :) The times are read CURRENT to the right...FUTURE to the left. So opposite of how you read a book. Unless you are like me and start with the last chapter right away :)
Red line- temperature
Green line- moisture/dewpoint
GFS starts the light snow near 7am Friday. Notice...how the temp stays pretty much LEFT of the freezing line (0°C) all the way up. Snow.
It brings in moderate snow near late morning/midday.
Then we get caught in a strong NW flow all the way into Friday evening. Upper levels dry out...but there is low level moisture closer to the surface. (when the red/green are close together--moisture...far apart---dry). So flurries/snow showers may continue until even 7pm Friday evening.
Snow ratios--- GFS starts off 15:1 (15" of snow to 1" of rain). Then drops to 10:1 as daytime heating kicks in.
With the mix of a 15:1 and 10:1 ratio--- GFS gives Louisville just over 1" of snow.
We actually do have a BUFKIT site for Madison, IN--- it gives you guys more than 1.5".
So with the GFS idea--- 1-2" would be common for the area----with sleet possibly mixing in closer to the TN border. Any "mix" area would cut down on any snow amounts certainly. But 95% of our counties---should be plain snow.
Now to the NAM. This model really has struggled. It had an ice storm yesterday at this time. Today--- it keeps the two streamed systems so far apart that only the southern one has any impact on KY...and even then...just a glancing blow.
BUKIT profile doesn't even bring in the light snow until 12 noon Friday...and quickly shuts of it off by 1pm.
NAM accumulation would be a dusting at best. Perhaps a bit more closer to the TN border closer to that southern stream system.
The latest EURO keeps the 2 streams separate---but close enough that it looks similar to the GFS. So another 1" idea.
The NOGAPS is similar to the GFS/EURO.
Canadian is more like the NAM.
So there you have it. Tons of model opinions :)
CURRENT THINKING
The GFS has held the general idea as of late...and the ensembles line up well with that model too. So I think the two streams will stay separate---but the snow should run like a "wave" across the area mid morning Friday into early afternoon---with additional light snow showers/flurries with the NW flow until mid Friday evening.
The ground is cold. Here is the latest road sensor off I-65 in Shelby County. Just barely above freezing.
Snow amounts of 1" look to be the main issue---but 2" amounts are possible with banding features/enhancement areas. While this isn't a lot of snow---I am concerned that it will cause more travel headaches than we have had with previous systems due to the cold ground. Look at what happened in Ohio over the weekend--barely a dusting and an 85 car pileup. Just one of those situations that everyone will need to use common sense in traveling---but not a system that will shut the city down of course.
We will keep an eye on moisture content ...increasing or decreasing..with future model runs this evening and Thursday. Expect more adjustments to amounts/timing once the system starts to actually show up in our upper air network tomorrow.
SUNDAY NIGHT
Another classic overrunning of warm air into the cold airmass. But this time---the warming is substantial.
GFS shows sleet/freezing rain profile Sunday overnight into very early Monday morning---but notice surface temps likely will range in the 32-34 range.
EURO also shows about 34. So if we can range 32-34---any icing impact would be VERY minimal. And still a chance the warming is so strong---we warm to 36+ and nothing but rain falls.
Nevertheless...it will be all rain as Monday wears on. The warming really kicks in Tuesday. EURO hints at 60°.
Later Tuesday/Wednesday---there will be showers/storms rolling through. Severe risk looks very low. On Wednesday---there is a low/wave that will develop along the front and race northeast on Wednesday.
Classic rain to light snow by Wednesday night. Likely flurries. Then cold Thursday.
FEBRUARY 5th
Date will waiver some...but cold Arctic air will return. And the storm track will start to pick up across the south. Just a pattern to watch.
Overall---the cold air that moves in by next weekend---looks colder..and longer lasting than the current cold spell. This looks to be the core of the winter season based on long term trends. Will the snow lovers finally see their "snow"? We shall see. The winter has been one of wishy/washiness---but it is far from over.
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