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KEY MESSAGES

* Beautiful Tuesday with a crisp morning, plenty of sunshine, and a warmer afternoon. Highs 75-80.

* A cold front will bring scattered showers during the early to mid- morning hours of Wednesday. There is a low probability (10%) of thunderstorms. Severe weather is not expected.

* Warming pattern returns for the end of the week into the weekend with near record breaking temperatures.

* Scattered rain showers possible through the weekend and a line of showers and thunderstorms possible Monday.

SHORT TERM /THROUGH WEDNESDAY/

Issued at 315 AM EDT Tue May 12 2026

Today...

A dry, cool airmass remains in place over the Ohio Valley early this morning. Sfc high pressure is analyzed over the Great Lakes. Skies are clear, and temperatures range from the mid 40s to mid 50s. A baggy pressure gradient will yield very light winds through the remainder of the morning.

A compact upper level trough and associated sfc low will rotate southeast across the Upper Midwest today. Low-level SW flow develops ahead of this wave as the sfc high shifts across the Mid-Atlantic coast. By 00Z this evening, the cold front is forecast to run from Lake Michigan southwest through northern IL/MO and southeastern KS. Notable low-level thickness increases and SW flow WAA will boost afternoon highs into the 75-80 degree range. Expect plenty of sunshine, with southwest winds of 5-10 mph in the afternoon.

Tonight and Wednesday...

Late tonight into Wednesday morning, the mid/upper level trough axis rotates southeast over the Middle and Upper Ohio Valley. We'll be positioned in the left exit region of a 100 kt upper jet streak streaming in from the northwest, but somewhat stronger forcing will pass off to our northeast. Low-level moisture return ahead of this progressive wave is meager, with sfc dewpoints only creeping into the low to mid 50s along and just ahead of the cold front. The cold front itself will sink southeast to near the Ohio River by 12Z Wednesday.

The narrow moisture plume along the cold frontal boundary will be characterized by max PW values near 1.0 inch. Given the decent lift provided by the upper level wave and low-level convergence along the cold front, quick-hitting rain showers appear likely Wednesday morning. CAMs suggest a couple thin rain bands may push southeast across southern IN and central KY, mainly between 06-15Z Wednesday. Instability should be near zero given the timing of the front and lack of richer low-level moisture. The probability of a thunderstorm is around 10%.

Some very modest instability (100-250 J/kg SBCAPE) may develop east of I-75 by early afternoon. Cannot completely rule out an isolated shower east of I-75 during the afternoon. However, a mostly dry afternoon is expected with NW flow CAA developing in the wake of the cold front. After topping out in the low to mid 70s, temperatures will fall back into the 60s by early evening.

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/

Issued at 315 AM EDT Tue May 12 2026

Wednesday Night - Friday

Winds will start to tamper down as the front/rain showers move out of the area Wednesday evening. Mostly clear skies and light winds will allow for the minimum temperatures to cool to the mid to upper 40s. As the upper level trough continues to move east, upper ridging and surface high pressure will build over the region. Clear skies and dry conditions are expected for Thursday with temperatures in the low 70s across the area.

Rain chances return Friday with scattered rain showers across the region due to a shortwave disturbance. A LLJ will move over the Ohio Valley overnight possibly bringing some gusty winds. Temperatures Friday afternoon will be in the mid to upper 70s, and nighttime lows in the mid 60s.

Saturday - Monday

Lingering rain showers will continue through the day Saturday as another shortwave ejects NE from the Central Plains. A warming patterns begins this weekend as a warm air mass moves into the region. Maximum temperatures Saturday through Monday will likely be in the mid to upper 80s. Areas west of I-65 have the best chance (60- 70%) of seeing 90 on Sunday, which will come close to records.

A low pressure system will build over the Dakota's on Sunday and will move NE into Canada. An associated cold front will stretch through the region bringing the next chance for rain Monday. A line of rain showers will move through Monday morning ahead of the cold front. Embedded thunderstorms will be possible (20-30%) as there is marginal instability. However, sounding data is showing a strong capping inversion which would prevent any severe potential. Wind gusts 20-25 mph will be possible as the cold front pushes through the area. The timing could possible shift as these rain showers are dependent on the movement of the cold front.

AVIATION /18Z TAFS THROUGH 00Z THURSDAY/

Issued at 130 PM EDT Tue May 12 2026

Flight categories through the forecast period look to remain VFR but we will see a few impacts in the forecast tonight into tomorrow morning. Sfc low centered over the Upper Midwest will drag a sfc cold front into the Ohio Valley overnight and be just north to along the Ohio River by 12z tomorrow morning. Models continue to indicate a broken area of showers just along or ahead of this boundary. Model soundings show a lot of dry air below 700mb so any showers that work their way into the area will have to overcome the dry air in place. That is why I went with a prob30. Winds will also increase and then veer from the southwest to the west then become more northwest behind the cold front. Wind gusts of 20-25kts are possible from late morning into the afternoon. Most of the rain chances should diminish by late morning with RGA seeing lingering shower chances into the afternoon.

LMK WATCHES/WARNINGS/ADVISORIES

KY...None. IN...None.