textproduct: Jackson

KEY MESSAGES

- Drier weather with modestly lower humidity will prevail through the end of the work week.

- Thunderstorms are possible at times from Saturday through Wednesday.

- Locally heavy rainfall is possible on Saturday and Saturday night and could lead to isolated instances of flash flooding.

UPDATE

Issued at 930 AM EDT THU JUL 30 2026

Some fog may remain, however fog continues to mix out throughout the area. Tweaks were made to the near term forecast to include the latest observational and model data from around the region. T/Td grids were freshened up, and the SAF was reran to remove wording of fog.

UPDATE Issued at 645 AM EDT THU JUL 30 2026

No significant changes were made to the forecast with mainly just the inclusion of the latest obs and trends for the T/Td/Sky grids. These minor adjustments have been sent to the NDFD and web servers along with a freshening of the zones.

LONG TERM

(Friday night through Wednesday) Issued at 435 AM EDT THU JUL 30 2026

The main change to the grids for the first part of the extended forecast this morning was primarily to include more in the way of PoP details and timing per the latest CAMs guidance on Saturday. It still looks like this next system is able to take advantage of increasing moisture pooling and a digging mid level trough crossing into Kentucky this weekend to bring an increasing threat for heavy rain - mainly on Saturday and Saturday night. The sfc pattern will feature a deepening and compact low pressure system rolling into the state on Saturday and Saturday night lifting and concentrating the available moisture - yielding a potential for heavy to excessive rain. Expect the quick arrival of convection by midday Saturday to limit the instability that can build up so that only a small threat for organized or severe storms are anticipated despite semi-favorable wind shear working over the CWA.

The previous long term discussion follows:

The long-term period opens Friday morning with an upper-level trough axis extending from Atlantic Canada southward along the Atlantic Seaboard. Meanwhile, an ~588 dam high will be in place over Arizona and New Mexico with broad ridging extending to the north across the Canadian Prairies. Less prominent ridging extends east and northeast from the high to across the Mid-Mississippi Valley, Ohio Valley, and beyond into Southwest Quebec. A sharpening and digging upper-level shortwave trough is also sliding across the Upper Midwest through the eastern side of the ridge. At the surface, high pressure, centered over West Virginia, dominates the the Central Appalachians and into adjacent regions. Meanwhile, low pressure is consolidating from Kansas to Iowa ahead of the shortwave trough (and will become our most significant weather maker of the forecast period).

The surface high pressure system and associated shortwave ridging aloft will shift east to along the Atlantic Seaboard by the end of the day Friday while the deepening 500 hPa shortwave dives southeast and the attendant surface low tracks across the mid- Mississippi Valley, moving directly over the Commonwealth Saturday night. Some of the energy within this trough will be captured by a broader 500 hPa trough pivoting through Eastern Canada and the Great Lakes. Guidance suggests whatever energy remains pinches off into a closed low that then retrogrades toward the Lower Mississippi Valley early next week and becomes entrapped under the eastward- building 500 hPa ridging. As a result, the surface low will occlude, sink southward, and decay on Monday. Meanwhile, a cold front associated with the trough passing through the Northeast will brush to our north and east.

As the low pressure system approaches, southerly flow will send PWATs rising to 1.75+ inches (around 80th percentile relative to climo) on Saturday, but those higher values will be short-lived overall as drier air sinks back in from the north behind the retrograding low and trough brushing to our north. WPC has a Marginal to Slight Risk for Excessive Rainfall over the JKL CWA on Saturday and Saturday night to account for the potential of locally heavy rainfall, which is the main concern in the long-term period. However, several days of antecedent drying as well as the overall progressive nature of the system should help mitigate hydro concerns. Fortunately, the instability and shear parameter space remains weak and that should preclude any notable severe convective weather threat.

Sensibly, look for increasing clouds on Friday and Friday night with high temperatures in the lower to mid 80s and low temperatures in the lower to middle 60s. Rain chances return on Saturday and peak at categorical PoPs Saturday night and early Sunday morning. Daily rain chances follow for Monday through Wednesday, but convective coverage should be more sparse and modulated by the diurnal heating cycle. Temperatures will continue to run in the lower to middle 80s for highs each afternoon (except upper 70s for some locations on Sunday), while nighttime lows dip into the 65 to 70 degree range for most.

AVIATION

(For the 18Z TAFS through 18Z Friday afternoon) ISSUED AT 123 PM EDT THU JUL 30 2026

VFR conditions will prevail through the 18Z TAF period, with mostly clear skies and light and variable winds. Patchy valley fog may develop this evening but shouldn't effect any TAF sites, and will be favored around or near river valley locations. Once the valley fog mixes out around 13-14Z, expect similar conditions to those of Thursday with light easterly winds developing Friday afternoon.

JKL WATCHES/WARNINGS/ADVISORIES

None.