textproduct: Louisville

KEY MESSAGES

* Storms are ongoing across south central IN and southern IL that will continue to move east into the forecast area. All severe threats remain on the table as these storms have a history of producing.

* A Flood Watch is in effect from 9 PM EDT tonight to 9 AM EDT tomorrow, mainly along and north of I-64.

* The cold front stalls across the region, leading to additional potential for scattered strong to severe storms, excessive rainfall, and isolated flash flooding across south-central KY Thursday afternoon and evening.

* A reprieve from rainfall comes Friday and Saturday before the next round of widespread rain returns starting late Saturday night.

SHORT TERM /THROUGH TONIGHT/

Issued at 133 AM EDT Thu Jun 18 2026

A low pressure system is currently centered over the Wisconsin and Illinois border with a cold front stretched SW through northern Illinois and north central Missouri. A low level jet is also centered over central Indiana that will begin to sink south slightly as the cold front starts to push SE.

Ahead of the front, a line of strong to severe storms will move through the Ohio Valley overnight. Southern IN counties can expect storms to start to move in between 12 and 2 am EDT, and continue to move SE into northern KY through the early morning hours. Storms will have the potential to produce wind, hail, and even a few tornadoes. The greatest severe potential remains in southern IN and northern KY along the Ohio River. The environment is expected to hold on to 1500 - 2000 J/kg with the capping expected to diminish through the night. Additionally, low level wind shear values will likely range from 40-50 kts as a strong low level jet is over the area through the night. There is a possibility that the lower level inhibition holds on and decreases the severe threat to the area by preventing any additional growth. PWAT values are currently hovering around 2" and are expected to hold steady. As storms move through this leads to a flash flooding concern, especially with training storms. QPF values will likely range 1" to 2" throughout the area, with some localized values of 3" possible with longer residence times. A Flood Watch is has been issued for the northern part of the CWA through Thursday morning.

Thursday afternoon and evening another round of severe storms are possible for central and southern parts of KY as the cold front slows over the Ohio Valley. As ample moisture stays in place over the region flooding will be an area of concern, along with damaging winds. A secondary Flood Watch for tomorrow is likely for areas in south central KY. The overall shear profile will weaken through the day tomorrow, deceasing the threat for tornado potential. Scattered rain showers and a few thunderstorms will move in behind this line of storms that will persist overnight.

LONG TERM /FRIDAY THROUGH WEDNESDAY/

Issued at 133 AM EDT Thu Jun 18 2026

The previously mentioned cold front will finally move out of eastern KY Friday morning, along with any lingering rain showers. Surface high pressure will build in behind the front bringing warm and dry weather. Northwesterly flow will become dominant keeping maximum temperatures on Friday in the low 80s with mostly clear skies. Dewpoints are expected to stay in the upper 50s and low 60s, leading to a very nice Friday. Saturday is looking to be a rinse and repeat with highs in the low to mid 80s.

Dry weather comes to an end for the later half of the weekend as a shortwave ejects from the Rockies Saturday night into Sunday morning. A surface low pressure will then form and move into the Ohio Valley. Widespread rain showers and scattered thunderstorms are expected to move ESE through the forecast area Sunday afternoon and evening into Monday. Severe threats are uncertain at this point, but is not out of the question. Instability seems to be marginal with the highest values remaining elevated. PWAT values greater than 1.5" will quickly build into the area ahead of the low. Long range guidance is estimating QPF near 1.5" by Monday night, therefore continued monitoring will be needed for any flooding concerns.

The surface low will move east out of the area Monday evening, with another area of high pressure building in behind it. Several chances for scattered rain showers through midweek will be possible as several shortwaves move through. However, chances remain low as the high pressure and drier air stays in place. Temperatures are expected to remain in the low to mid 80s through midweek.

AVIATION /06Z TAFS THROUGH 12Z FRIDAY/

Issued at 127 AM EDT Thu Jun 18 2026

Gusty southwesterly winds will prevail through the overnight period. A line of showers and storms will drop south through the overnight hours. Some storms will be strong to severe bringing a chance for severe weather hazards and heavy rainfall. This line of showers and storms will weaken as it moves south. VIS will likely drop to 1-2SM at times. South of I64, CIGs are expected to be high-end MVFR in the morning and into the early afternoon and showers and storms continue.

LMK WATCHES/WARNINGS/ADVISORIES

KY...Flood Watch until 9 AM EDT this morning for KYZ025-029>043-049. IN...Flood Watch until 9 AM EDT /8 AM CDT/ this morning for INZ076>079-083-084-089>092.