textproduct: Jackson

KEY MESSAGES

- Independence Day will be hot and a little more humid. High temperatures will reach the upper 80s to low 90s.

- The weekend brings the hottest air. Expect widespread high temperatures of 90 to 95 degrees, feeling oppressive at times, with a low chance of isolated afternoon showers or thunderstorms, mainly on Sunday.

- A more active weather pattern begins Monday with the threat of daily thunderstorms, some of which could bring locally heavy rain. Though still oppressive on Monday, daily high temperatures gradually ease into the mid to upper 80s by mid- week.

LONG TERM

(Saturday through Thursday) Issued at 300 PM EDT THU JUL 3 2025

Hot, humid and generally rain-free conditions over the weekend will transition to an unsettled weather pattern heading into the new work week. The analysis based on the 03/12z model suite, beginning Saturday morning, shows a 500H ridge axis stretching from northwest Mexico to the Ohio Valley. A broad associated surface high is centered near/over the Delaware River Valley. Multiple Pacific shortwaves are riding over the ridge, the first of which will be over the Upper Midwest, interacting with a much deeper upper level trough over the Hudson Bay to northwest Greenland. This supports a potent low over the Hudson Bay with a cold front extending to a weak surface low pressure wave over Minnesota. From there, the front extends westward to over Montana where a second Pacific shortwave is crossing the northern Rockies.

The ridge aloft reaches its peak strength over the Commonwealth on Saturday before partially breaking down on Sunday as the first shortwave trough settles southeast toward the Ohio Valley. The weekend days will feature the hottest air mass (850 mb temps of 20-21 Celsius) aloft while, at the same time, humidity levels rise due to the southerly return flow on the back side of the surface high. Enough height falls and moisture increase are anticipated by Sunday afternoon for isolated afternoon pop-up convection. Right now the greatest opportunity for rainfall on Sunday appears to be near/over the higher mountains adjacent to the Virginia and Tennessee borders. Rain chances become more widespread on Monday/Monday night as the first shortwave guides its associated cold front into eastern Kentucky. As the features better forcing skirts to our north on Tuesday, guidance is muddled as to how far south the boundary will actually reach before stalling. A weak wave of low pressure, forced by the second 500H shortwave trough, then rides along the stalled boundary into the Ohio Valley mid- week. The waffling frontal boundary and low pressure wave will keep diurnally-modulated convection in the forecast through the remainder of the long-term forecast period. As 850 mb temperatures ease back into the 17-18 Celsius range by mid-week, PWATS are conversely favored to rise above 1.5 inches for most of the time from Monday afternoon onward. Of particular note, the modeled combination of a very moist atmosphere, a deep warm cloud layer, skinny CAPE profiles, and generally weak steering flow will be favorable for locally heavy rainfall.

In more sensible terms, look for a quintessential Fourth of July weekend with a lot of heat and rising humidity levels -- perfect weather for the first dog days of summer. Saturday is favored to have the hottest air temperatures of the two weekend days with highs ranging from 90 to 95 degrees, but moderate humidity levels will still keep it from feeling too oppressive. Saturday night will still cool off decently into the mid 60s to near 70. Sundays air temperatures are forecast to peak about a degree cooler than Saturday but higher humidity levels will still make it feel like the middle 90s. Mostly sunny skies are likely on both days with a little more cloud cover on Sunday, when there will also be a low- end chance of a popup shower or thunderstorm. A daily scattered to numerous thunderstorm threat returns on Monday and continues through the remainder of the period. Some of the showers and thunderstorms could produce heavy rain. Under the more humid regime, daily high temperatures continue subsiding back into the mid to upper 80s by mid-week. Heat indices will follow a similar trend, after peaking in the 95 to 100 degree range for most locations on Monday afternoon.

AVIATION

(For the 18Z TAFS through 18Z Friday afternoon) ISSUED AT 126 PM EDT THU JUL 3 2025

A widespread cumulus deck has developed across the area with this TAF issuance. This cloud deck is VFR and as a result, terminals will be VFR. Clearing is expected overnight tonight but river valley fog is forecast to develop which could cause category reduction after 08Z and through 13Z. Once fog dissipates, terminals will return to VFR. Lastly, light and variable winds are expected through the period.

JKL WATCHES/WARNINGS/ADVISORIES

None.