FXUS63 KLMK 111453 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 953 AM EST Mon Dec 11 2023 ========================================================== Key Messages: - Below normal temperatures today - Predominantly dry weather and seasonable temperatures ========================================================== .Forecast Update... Issued at 951 AM EST Mon Dec 11 2023 GOES satellite imagery shows stratus layer scattering out across the area as the 850-mb thermal trough slowly lifts and daytime heating increases. Satellite also shows a mid-level cloud deck moving in from the west associated with a small vorticity impulse, but given subsidence in the AVA of the departing trough, most of these clouds may dissipate before progressing through central Kentucky. As a result, went ahead with HREF 11/0Z sky cover that reflects a quicker clearing trend this afternoon. Otherwise, no major changes are anticipated with this update as surface high pressure remains in control. && .Short Term...(Today and tonight) Issued at 307 AM EST Mon Dec 11 2023 GOES low cloud IR imagery shows low stratus continuing across much of the region this morning. The western edge of the cloud cover extends from Dubois county IN southeastward to just east of Bowling Green. The cloud cover has resulted in a gradient of temperature across the region. Under the clouds, temperatures were in the lower 30s, but out across our far west in the clear skies, temperatures were in the low-mid 20s. Based on recent satellite imagery, we're not expecting the stratus to really make any headway in moving eastward and most locations will likely keep the stratus deck through sunrise. In the near term, no significant weather is expected. Overnight lows will be in the lower 30s under the clouds, with lower-mid 20s out across the far west in the clear skies. For today, high pressure out to the west will build eastward. Cloud cover should start to mix out by mid-late morning and then continue into the afternoon. Winds will start off out of the northwest this morning and then gradually back to the southwest in the afternoon hours. As for temperatures, highs will range from the lower 40s over SE Indiana and the Bluegrass region of central KY to the lower/mid 40s over our far southwestern areas. For tonight, high pressure will be located to our east and we'll see a continued light flow out of the south. Current thinking is we'll see a ridge/valley split with the decoupled/protected valleys going into the low-mid 20s with the ridges staying in the upper 20s to around 30. && .Long Term...(Tuesday through Sunday) Issued at 250 AM EST Mon Dec 11 2023 On Tuesday, dry weather will be prevalent across much of the CONUS east of the Rockies. An upper level trough will slide across Ontario and the Great Lakes region, taking an associated surface cold front with it as it translates eastward Tuesday night into Wednesday. We'll be on the southern edge of this cold front, with forcing and moisture expected to be minimal with this system. As a result, substantial weather changes are not expected with this front. Despite a lack of lower troposphere moisture, mid- and upper-level moisture should help bring in a few extra clouds Tuesday night into Wednesday. Winds should gradually veer from SW on Tuesday to N/NE by Wednesday, helping to bring marginally cooler air into the region. For the second half of the upcoming week, there should be a gradual warming trend across the Ohio and Tennessee Valleys as mid- and upper-level ridging builds across the Mississippi Valley and spreads eastward by early next weekend. A cutoff upper low across the southwestern U.S. will meander east-southeastward, with its associated moisture plume now expected to remain well west of the region through at least Saturday morning. As such, there is high confidence in dry weather for late this week into early next weekend. Precipitation chances for the second half of the weekend into early next week are also decreasing as newer medium range guidance comes in. With the preponderance of guidance keeping the cutoff low suppressed southward into the Gulf of Mexico, moisture advection will struggle to make much if any northward progress, with a fairly dry air mass remaining in place over the Ohio and TN Valleys. A northern stream shortwave may bring some moisture with it as it passes by Sunday, but without support from any enhanced meridional flow which would come from phasing with the low over the Gulf of Mexico, any disturbance that passes through the region would struggle to produce any precipitation. Have continued to delay and trim back PoPs this weekend, and would expect to continue to trend toward a dry forecast given recent guidance. Above normal temperatures are favored this weekend, with highs in the mid 50s and lows in the upper 20s and low-to-mid 30s. && .Aviation...(12Z TAF Issuance) Issued at 615 AM EST Mon Dec 11 2023 Morning IR satellite imagery shows that the low stratus has been attempting to scour out. So far, it's been a little more successful over the Bluegrass region, but not over north-central KY. However, after sunrise, we should start to see skies scour out with cigs returning to VFR. Winds this morning will start off out the northwest at 2-5kts and then back to the southwest this afternoon. For tonight, VFR conditions are expected with light winds. The outlook for Tuesday calls for VFR conditions as high pressure becomes the driver of our weather for the next several days. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Update...ALL Short Term...MJ Long Term...CSG Aviation...MJ