Significant Winter Storm Expected

Well... this is about to get interesting.
Well… this is about to get interesting.

Today 3/2 – Scat’d Rain Showers to Wintry Mix – High 50˚ / Tonight – Wintry Mix Likely, Breezy – Low 20˚

7am 50˚ ~ 9am 42˚ ~ 12pm 37˚ ~ 3pm 34˚ ~ 6pm 32˚ ~ 9pm 30˚

**Winter Storm Warning for Butler and Edmonson Counties valid after 8am CST.  Winter Storm Warning for Allen, Barren, Logan, Simpson, and Warren Counties valid after 3pm CST.**

WARNING: Complex forecast ahead…grab a bag of popcorn, relax, take it slow and read on.

As expected, scattered showers have developed across the area this morning. Overall, rain is fairly light for the time being.  As this scattered shower activity continues through the morning, rain totals for most locations will remain below 0.25″.  No worries for ice this morning (temps in the 40s), so travel to and from services shouldn’t be any major problem.

Currently, these showers are generally along and just behind a cold frontal boundary which currently slices through south-central Kentucky.  The front should pass completely through our region by noon, allowing much colder air to filter in.  Meanwhile, precipitation will increase in intensity and coverage this afternoon just behind the passage of the cold front.

Surface conditions valid ~5:15 am. Note the freezing line (dashed purple) is now pushing into KY.

Temperatures will quickly drop from the mid to upper 40s this morning into the mid to low 30s this afternoon. Locations will begin to fall below freezing, and subsequently, rain will become freezing rain allowing for ice accretion to begin.

As you may expect, this changeover will occur NW to SE. Locations to the NW such as Butler County are expected to see this changeover occur first in the 11am-3pm time frame; locations such as Bowling Green will be more like 3pm-8pm, while areas to the far SE (eg. Allen Co) will transition between 5pm-10pm.

Throughout the overnight hours, most locations should see a gradual transition from freezing rain to sleet, and then from sleet to snow.  Precipitation could be quite intense at times, thanks to warm, moist air being pumped up and over shallow cold air at the surface by a process known as isentropic lifting.  An upper level disturbance will contribute to this process and will help to focus areas of snowfall by Monday morning.  Don’t be surprised if you hear a few rumbles of thunder with the most intense precipitation.  Yes…you heard me correctly.

Take a look at this model, the 4km High-Resolution NAM to get a better idea of the timing and changes in precipitation type.  Pink is freezing rain, orange is sleet, and light blue is snow.  Note that I believe the period of freezing rain will be longer than this model indicates, but you get the overall idea:

Valid 9am Sun – 12pm Monday is 3 hour increments.

With this extended period of, at times intense, winter precipitation, significant totals could result for our area.  Ice accretion totals (glaze) are expected to range from 0.20″-0.75+”.  Sleet totals could be as much as 1-2+”, while snow totals are expected to be a general 2-4″ (isolated up to 6″) across areas further to the north, with 1-3″ across the southern counties.

WPC probability of ice >=0.25" from 12pm Sun - 12pm Mon
WPC probability of ice ≥ 0.25″ from 12pm Sun – 12pm Mon
WPC probability of snow accumulation ≥ 2" from 12pm Sun - 12pm Mon
WPC probability of snow accumulation ≥ 2″ from 12pm Sun – 12pm Mon

The significant ice totals alone will create the potential for falling tree limbs, downed power-lines, etc.  Add in noteworthy snow on top of ice accretion, along with 10-20 mph NE winds overnight Sunday into Monday morning, and these hazards could be worsened.

Make preparations to possibly spend some time without power.  This especially includes a way to stay warm, as temperatures look to remain below freezing through at least Tuesday.  Having plenty of non-perishable food and water is also recommended.

Roads will inevitably become hazardous this evening and will remain as such well into Monday.  By Monday morning temperatures will be near 20˚.  Thus do not make plans to travel during this time frame if at all possible.

Mon – AM Snow Likely, Flurries – High 27˚ / Mon Night – Mostly Clear, COLD – Low 

**Winter Storm Warning for Allen, Barren, Butler, Edmonson, Logan, Simpson, and Warren Counties valid until 12pm CST.**

We will likely find ourselves on the NW side of the exiting weather system by Monday morning in a region often known as the “wrap-around.” This will allow scattered light to moderate snowfall to occur across the region through the morning, continuing until roughly around noon.

We may see a peak of sun late in the afternoon, but for the most part, the remainder of the day will be cloudy with areas of scattered flurries possible.

Overnight, skies will clear out allowing for temperatures to take a nose dive. That along with widespread snow/ice cover at the ground will allow many locations to fall into the single digits.

If power outages do result from the storm and continue through Monday night, a good heat source will certainly be needed. Keep that in mind when doing last minute preparations this morning.

Tue – Mostly Sunny – High 33˚ / Tue Night – Partly Cloudy – Low 17˚

The weather will be much calmer by Tuesday with, in general, a broad area of high pressure in control. A few clouds may roll in Tues evening but otherwise just cold as near or below freezing temperatures continue. As a result, roads will likely remain hazardous in some locations if the winter weather indeed occurs.

That’s all for this blog post… @Wx_Or_Not and @WarrenCountyWx will have continuous updates on twitter as the event unfolds. We’ll also be back to give you a fresh update this afternoon. Make any last minute Winter Storm preparations this morning while you have the chance. Stay safe and thanks for reading!