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 Tuesday.

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

LONG TERM

(Friday through Wednesday) Issued at 357 PM EDT WED JUL 29 2026

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 Thursday afternoon) ISSUED AT 128 PM EDT WED JUL 29 2026

VFR conditions are expected through the TAF period. A scattered cu deck remains across the area through 00-02Z. Some patchy fog may develop between 09-12Z but should remain confined to the river valleys. The area will remain under light northerly winds.

JKL WATCHES/WARNINGS/ADVISORIES

None.