Louisville, Kentucky

Updated Aviation Discussion

• Cloudy skies with scattered rain showers are expected today and into tonight.
• Short period of dry weather expected for Monday and Tuesday with mild/breezy conditions.
• Unsettled weather returns by late Tuesday and Wednesday as the next weather system moves through the region.

Now through Tuesday

Current sat/obs show cloudy skies across the region with temperatures ranging from the upper 50s to the lower 60s. Antecedent dry atmosphere will continue to take some time to moisten from top to bottom. Saturation has already occurred out across far western Kentucky where a few light rain showers were observed. For the remainder of the overnight period, we`ll see cloudy skies continue with scattered sprinkles mainly west of the I-65 corridor. As a weak LLJ starts to develop, combination of isentropic lift and synoptic scale lift from an approaching shortwave trough axis should result in an increase in rain showers, in the I-65 corridor and points west.

For today, aforementioned shortwave trough axis will lift northeastward across the region. A weak LLJ will gradually translate eastward through the day. Low-level dry air will likely hold on during the morning and will limit overall areal coverage of rain showers. However, top-down moistening will occur and light rain showers are expected across the region this afternoon and into this evening before the shortwave trough pulls northeast of the region. Rainfall totals will likely be in some sort of gradient with a tenth of an inch or less across southern Indiana and into the Bluegrass region of central Kentucky. Rainfall amounts of a quarter to perhaps a half inch will be possible across our southwest areas. Clouds will keep daytime highs a bit cooler today with lower 60s expected across the southwest areas, elsewhere highs in the mid-upper 60s are expected. Lows tonight will cool back into the upper 40s/lower 50s.

For Monday/Tuesday, short duration ridging will build across the area ahead of a deepening trough axis in the Plains. A warm southwest flow will be seen across the region with highs on Monday warming into the upper 60s/lower 70s over southern IN and into the Bluegrass region. Lower 70s are expected in the I-65 corridor and down into the Bowling Green area. Lows Monday night will be in the lower 50s in the I-75 corridor and in the mid-upper 50s elsewhere. Dry/milder/breezy conditions are expected on Tuesday with highs warming into the upper 70s. Would not be surprised to see a few low 80s in spots given the strong warm advective scheme that will be in place.

Tuesday Night through Saturday

By Tuesday night, a large closed upper level low is forecast to be over the upper Midwest with a large trough axis extending southward along the MS River. A north-south oriented cold front will move into western KY late Tuesday evening and will cross through central KY Wednesday morning. Ahead of the front a line of showers and perhaps a few embedded thunderstorms. The main trend in tonight`s guidance is a faster progression of the front through the region on Wednesday and much drier forecast for Thursday. By Friday a secondary upper level wave will move through the region bringing another round of rain showers to the region. A third upper level wave looks to enter the region by Sunday and will bring another round of showers to the area. Total rainfall with these systems will be on the order of 1-2 inches with some localized 3+ inch amounts. Highs Wed/Thu will be in the upper 60s to around 70 with overnight lows in the 50s. Cooler temps are expected on Fri/Sat with readings in the mid-upper 60s.

Conditions will likely remain VFR through the day. An area of light rain showers over western TN/KY will move northeastward and expand in area later this morning. Initially, dry air in the lowest levels will keep a lot of the precipitation from reaching the ground until we saturate from top to bottom. KHNB/KBWG will see this saturation take place first, but KSDF may not see measurable rainfall until later this afternoon. KLEX/KRGA look to remain dry through the daytime hours. Surface winds will remain out of the southeast at 5-8kts. For tonight, cigs will likely lower into the MVFR range with drizzle and light rain continuing. There is a pretty strong signal for KHNB to drop to IFR cigs later this evening.

KY

None.

IN

None.