textproduct: Jackson

KEY MESSAGES

- A strong cold front could produce multiple rounds of thunderstorms today into tonight.

- There is a Slight to Enhanced Risk for severe storms today, including damaging winds, large hail, and isolated tornadoes.

- Torrential rainfall from persistent thunderstorms could lead to flash flooding this afternoon into tonight.

- Mainly dry weather is expected from Wednesday night to Friday, with temperatures averaging about 5 degrees below normal.

UPDATE

Issued at 755 AM EDT TUE JUL 21 2026

Hourly grids have been freshened up based on recent radar and convective allowing model trends. With little upstream convection at this doing or over the area and passing cloud cover, lowered pops a bit through midday or early afternoon. Otherwise, other than freshening up temps based on observations, no additional changes were made at this point.

LONG TERM

(Wednesday night through Monday) Issued at 525 AM EDT TUE JUL 21 2026

The models remain in generally good agreement with an amplified and stagnant long wave pattern to rule over the CONUS through early next week. The center of a seasonably strong upper level ridge will meander/retrograde northwest from the southern Plains to the Four Corners region and building into parts of the Central Plains to Lower MS Valley at times, while broader troughing modulates east of the Mississippi River with it's axis aligned from near the Ontario and Quebec border to the mid Atlantic coast to east of the southeast US coast. This will result in a reprieve from the humidity across the Ohio and Tennessee valleys at midweek into early Friday. However, humidity will be on the increase once again across the region by Friday afternoon and into early next week.

By Wednesday evening, a surface cold front should have pushed well into VA to the Smokes to the Lower MS Valley, and high pressure building into the Lower OH Valley form the Upper MS Valley. Wednesday night, welcomed northeasterly low level winds ushering in much lower dew points than has been experienced this month. Some fog will likely on Wednesday night into early Thursday morning and some of this could be dense in some more southern locales. However, although the pressure gradient/mixiness may limit this coverage. Drier and cooler weather will be in full swing on Thursday, with valley fog favored with high pressure dominating on Thursday night.

As troughing sharpens back up over the Ohio Valley Friday to Saturday, shortwaves moving southeast within the established northwesterly flow aloft between the trough axis to the east and northeast and the ridging in the western to south-central Conus. Model details regarding timing remain lower confidence this far out, but rain chances will return as some moderate moisture advection occurs in the low levels, with LREF mean PWATs of 1.4 to 1.5 inches nosing back into southeastern portions of the Commonwealth by Friday. PoPs look to peak Friday night into Saturday, with somewhat better model agreement on increased mid and upper level forcing in place from one of the shortwaves. For the rest of the weekend and early next week, despite the favorable stormier track that northwest flow can mean aloft, mean PWATS right now remain in the 50th to 75th percentile, so only slight to chance PoPs are in the forecast for Sunday through Monday.

Highs will remain cooler than normal by about 5 degrees on Thursday, before gradually warming to the mid to upper 80s by SUnday Monday. Overnight lows will moderate from the upper 50s and low 60s Wednesday and Thursday nights, to the upper 60s and around 70 by early next week.

AVIATION

(For the 12Z TAFS through 12Z Wednesday morning) ISSUED AT 805 AM EDT TUE JUL 21 2026

At issuance time, VFR was occurring from the TAF sites north with a bit of lingering fog and low ceilings near the VA border. The low clouds and IFR or lower ceilings and/or vis near the VA border in the K1A6 and KI35 vicinity should lift and dissipate by 14Z and for a time give way to prevailing VFR ahead of an approaching cold front. Showers and thunderstorms should affect the region along and ahead of it, mainly after 18Z. The greatest coverage of activity is anticipated between about 20Z and 04Z. For a few hours during that time have included thunder on station at the TAF sites with PROB30 groups a few hours either side of that window for thunder. When thunder occurs on station, it could be severe with peak wind gusts of 40KT or higher possible with a period of IFR or worse conditions. Winds should generally increase to 7 to 15KT range from the southwest after 15Z as the front nears with some gusts as high as 20 to 25KT. Stronger winds and gusts are expected in storms as already noted. Winds should trend more west to northwest late, generally slackening behind the leading edge of a strong to severe line of storms.

JKL WATCHES/WARNINGS/ADVISORIES

Flood Watch from 1 PM EDT this afternoon through late tonight for KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120.