textproduct: Jackson

KEY MESSAGES

- Showers and thunderstorms today into this evening will bring the possibility of heavy rainfall and strong to damaging wind gusts. Training thunderstorms could lead to localized flooding.

- Lower humidity and dry weather arrive by late Tuesday and last through Wednesday.

- Unsettled weather is forecast to return to end the week and into the weekend with rounds of showers and storms possibly producing heavy rain and a flood threat.

LONG TERM

(Wednesday through Monday) Issued at 340 PM EDT MON JUN 22 2026

The period begins with broad troughing from parts of the Central to eastern Conus and an upper level ridge centered near the TX/NM/Mexico border area and extending across the Four Corners to parts of the Great Basin and interior northwest. Also at that point, an upper level low is progged to be centered near the Ontario/ Manitoba/ MN border area with shortwave rotating around this upper low near the Great Lakes with another shortwave trough extending to the Central Plains. Further upstream an upper low is expected to be in the Gulf of Alaska vicinity with an upper trough south southeast to just west of the Pacific northwest. Shortwaves moving through this trough should be working around the ridging extending into the western Conus and across sections of the Pacific northwest and western Canada. At the surface, high pressure is expected to be centered over southern OH/the OH Valley region to begin the period with a sfc low in the upper MS Valley nearing the western Great Lakes with its frontal zone trailing into parts of the Central Plains to sections of the Rockies. As the period begins, a dry airmass for this time of year is expected to be in place, in the 0.5 to 0.8 inch range or roughly the 2nd to 9th percentile per the 12Z HREF mean.

Wednesday through Thursday night, the initial broad troughing pattern evolves to more of a westerly/zonal flow pattern east of the crest of the Rockies across the central Conus to the mid Atlantic sates with broad upper level ridging becoming centered in the Southern Plains vicinity, with another upper level ridge centered between the Bahamas and Bermuda. Further north, the upper low should weaken to an open wave as it moves across the northern Great Lakes and sections of Ontario into Quebec and potentially becoming an open wave. Meanwhile, a couple of weather shortwave troughs may cross the area Wed to Thu before a shortwave that initially is moving around the ridging extending across the western Conus moves into the northern and central Plains/Central Conus Wed and Wed night and then into the mid MS Valley/Lower OH Valley by late Thu night. Models begin to vary at that point in timing and the general consensus is for another shortwave further upstream in the Central Conus at that time. At the surface, high pressure will shift east of the area for Wed and Wed night with a developing warm front crossing the area Wed night into early Thursday as the sfc low gradually moves across the Great Lakes and and eventually into Ontario. The trailing cold front should advance to the eastern Great Lakes to lower OH and mid MS Valley to portions of the Plains by late Thu night. Behind the warm front, moisture will gradually increase with PW per the 00Z LREF mean reaching the 70th to 75th percentile by around dawn on Friday or the 1.4 to 1.6 inch range. During that time, sfc dewpoints should generally reach the mid to upper 60s by Thursday night.

Following below normal temperatures on Wed and a moderate magnitude ridge/valley split for Wed night , temperatures begin to moderate back to near normals for Thu. As moisture increases and the shortwave and cold front begin to near late Thu into Thu night, the threat for showers and thunderstorms may return, though chances should peak to begin the weekend.

Friday to Saturday night, a series of shortwaves crossing the OH Valley and portions of the Appalachians is the general consensus of guidance for Friday into early Saturday. At the same time, the upper level ridge initially extending across portions of the Rockies will build into the Plains/Central Conus late Fri into Saturday downstream of an upper low that reaches the Northwest Conus and an upper trough that moves into the western Conus. The axis of the upper level ridge should near the MS Valley and possibly western Great Lakes by late Saturday night. Northwest flow aloft should remain after the shortwaves pass to the east. At the same time, the frontal zone should become stalled out over the OH Valley/eastern KY area to end the week and continue into the weekend. PW should climb even more during that time, though without a strong connection or feed from the Gulf, 00Z LREF PW values peaking roughly in the 85th to 95th percentile range to end the week of the 1.5 to 1.75 inch range. This pattern appears favorable for rounds of storms from time to time or MCS type activity. Some stronger convection could occur if sufficient instability were be build Friday or Saturday, though the potential repeated rounds of showers and storms may result in locally heavy rain and an isolated flood threat at some point, possibly as early as Friday or Friday night. WPC has included eastern KY and points west to near the Ozarks in a marginal Excessive Rainfall Outlook for Day 5.

Sunday to Monday, a period of height rises with the upper level ridge axis approaching or nearing eastern KY is the general consensus of guidance to begin next week. Further west, the axis of the upper level trough moves gradually east over sections of the northern Rockies to southwest Conus. A preceding sfc low should travel across western sections of Canada generally north of the US/Canadian border with the trailing cold front moving into sections of the Central Conus and the boundary initially stalled over the OH Valley vicinity lifting northeast as a warm front late in the period. Pending the positioning of the upper level ridge axis and considering the gradual height rises, capping should lead to a min in convective coverage or potentially keep the region entirely capped by Monday. Warming temperatures are also possible and if the ridge is centered over the area on Monday temperatures may reach around 90 or the low 90s in many areas. A scenario more like the recent ECMWF runs would be slower moving the front northeast as warm front with potentially some convection on Monday and temperatures lower than the current forecast for Max T on Monday.

AVIATION

(For the 18Z TAFS through 18Z Tuesday afternoon) ISSUED AT 437 PM EDT MON JUN 22 2026

The period start with largely VFR conditions across the forecast area. However, there were showers/thunderstorms bubbling up as daytime heating began to make it influence, and these were bringing localized IFR or worse conditions. That should continue to be the case into this evening. An increase in precip is expected during the evening as an upper level disturbance approaches from the west southwest. This is forecast to bring generalized reductions to MVFR, with IFR or worse at times in the heavier precip. The precipitation is forecast to taper off from northwest to southeast overnight and early Tuesday, but IFR or MVFR conditions will probably linger longer. VFR should begin to return from the northwest on Tuesday.

JKL WATCHES/WARNINGS/ADVISORIES

Flood Watch until 11 PM EDT this evening for KYZ044-050>052- 058>060-068-069-080-085>088-104-106>120.