Forecast Discussion 00:19:13.1152

…Updated Aviation Discussion…

.Forecast Update…
Issued at 950 PM EST Wed Nov 16 2022

Shortwave embedded in the upper-level trough continues to work across the Ohio Valley this evening. With steep low-level lapse rates and help from a LLJ of 25-30kts we’ve seen snow showers over the northern half of our CWA. Current observation and KLVX WSR-88D radar imagery has a swath of light to moderate snow showers moving through the Bluegrass with the heaviest bursts of snow located across Washington, Mercer, Boyle and Jessamine counties northward towards Cincinnati, OH. These snow showers should continue to quickly move off to the east and exit out of the area between 04- 05z. Most locations have seen a quick dusting on cars and elevated surfaces.

Snow will taper off but low stratus behind the trough located over central/northern IL will move in over southern IN/northern KY. Because of the clouds decided to increase overnight lows in southern IN/norther KY up a few degrees.

Issued at 550 PM EST Wed Nov 16 2022

Monitoring area WSR-88D returns, observations and traffic cameras from both Indiana and Kentucky decided to up our PoPs to around 20 percent for some scattered light snow and flurries through this evening. Impacts remain minimal but a brief burst of snow in an isolated band, especially across southern IN and norther KY along the Ohio River is possible. SPC Meso-analysis shows a 25kt 850mb LLJ over northern KY and southern IN this evening with the RAP
suggesting we could see areas up to 30kts adding to slight enhance lift. Model soundings and cloud tops support areas of saturation in the DGZ along with some steep low-level lapse rates where we had sunshine close to 6 C/km. While there is support for light snow we have dry a dry layer below 3K ft keep most of the snow showers light to just flurries. Temperatures will also remain slightly above to just near freezing during the time of highest PoPs and ground temperatures as well as road temperatures remain above freezing.


.Short Term…(This evening through Thursday)
Issued at 315 PM EST Wed Nov 16 2022

After some sunshine filtering through this afternoon as drier air set in, we will see low level clouds move over central KY from the west. Breezy westerly winds will eventually die down by this evening as daytime mixing diminishes, but west winds should remain between 5- 10 mph overnight. We are currently located underneath broad upper troughing, with another subtle shortwave expected to pass through the Ohio Valley tonight. Several hi-res CAMs have been hinting at a quick moving wave of wintry precip this evening as a vort lobe swings through. Model soundings show a shallow layer of moisture tapping into the DGZ this evening, with steep low level lapse rates but a decent dry layer at the sfc will likely limit most precip chances. No accumulations are currently expected, though should we be able to tap into more moisture, the steep lapse rates will result in brief snow showers that could result in very light accumulations. Not entirely confident on this, but given the broad ascent over the area it is possible. Will blend hi-res guidance to highlight an area of sprinkles/flurries for a short period mainly across central KY tonight. Lows for tonight will drop down into the low to mid 20s.

For tomorrow, the upper flow flattens into a more zonal pattern. A dry forecast is expected for tomorrow, with the greatest cloud coverage expected along and north of I-64. With this in mind, cooler high temps are expected across southern IN, with mid 30s possible. Temps closer to 40 are expected to the south across Kentucky.

.Long Term…(Thursday night through Wednesday)
Issued at 300 PM EST Wed Nov 16 2022

Thursday Night – Sunday…

A cold front will bring a reinforcing shot of cold air to the region for the weekend. Expect unseasonably cold temps with highs in the 30s to low 40s and low temperatures in the teens and low 20s Fri- Sat-Sun.

In addition to the cold air, the front could also bring a few flurries/sprinkles to the area late Thu night into Fri morning but feel the majority of the model soundings are too dry to mention any precipitation in the forecast attm. Sat-Sun look dry with sfc high pressure moving in from the west.

Monday – Wednesday…

By Monday, return flow should commence as the high pressure moves eastward out of our area. This will result in a warming trend through mid week. High temps will moderate into the 40s for Mon with 50s for highs by Tue/Wed.

12Z long range models indicate an upper level shortwave could bring a slight chance for precip to the area Tues. However, the best chance for the return of rain should come Wed-Thu ahead of a potent low pressure system over the central U.S.


.Aviation…(06Z TAF Issuance)
Issued at 1215 AM EST Thu Nov 17 2022

A wide area of low-end VFR to MVFR stratus/cigs across the Midwest is pushing into the region early this morning. While the southward extent of the stratus is not being handled or initialized well by model guidance, based on latest satellite trends and RH trajectories in the low levels, expect it to impact most TAF sites across the CWA for a good portion of the forecast period. It may not be until early afternoon that we begin to see breaks in the stratus develop.




Short Term…CJP
Long Term…AMS