983 FXUS61 KRLX 290935 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 535 AM EDT Mon Jun 29 2026 .WHAT HAS CHANGED... Forecast thinking remains largely similar to the previous package. Updated 12Z aviation discussion. && .KEY MESSAGES... 1. Fog this morning will dissipate shortly after sunrise, giving way to isolated afternoon showers and thunderstorms primarily over the mountains. 2. A prolonged period of dangerous heat and humidity builds Tuesday through Friday. 3. Thunderstorm chances increase heading into the upcoming holiday weekend. && .DISCUSSION... KEY MESSAGE 1... Observations at this hour indicate fog developing across the region, particularly within river valleys, with visibility already dropping to less than a mile at some airport locations. Mid-level cloud cover streaming across the middle Ohio Valley is slightly impeding widespread radiational cooling and may delay additional fog formation in some areas. Will likely issue a special weather statement a little later this morning to cover restricted visibilities in fog for the morning commute. Isolated to scattered showers and thunderstorms will be possible this afternoon and again on Tuesday, primarily confined to the Northeast Mountains and southern coalfields prior to the core of the approaching ridge getting overhead. The kinematic profile supports unorganized, pulse-type convection. KEY MESSAGE 2... An anomalously strong H500 ridge will approach from the west on Tuesday and move directly overhead by Wednesday and Thursday. Subsidence beneath this feature will yield hot and humid conditions. Central guidance currently forecasts widespread afternoon high temperatures in the mid to upper 90s, with dew points remaining in the upper 70s. The National Blend of Models has a known high bias regarding dew points during these synoptic setups. Therefore, the forecast deviates from central guidance by dropping mixed afternoon dew points down into the lower 70s. Even with these reduced dew points, the combination of upper 90s ambient temperatures will produce apparent temperatures nearing or exceeding 100 degrees, placing much of the lowlands into heat advisory criteria for Tuesday through at least Thursday, and possibly Friday. Some low end warning criteria (105F) is also possible. In collaboration with neighboring offices it was decided to defer the product decision to the day shift given some uncertainty in both maximum temperatures and afternoon mixed dew points, but there is high confidence in heat headlines of some description for Tuesday through at least Thursday. KEY MESSAGE 3... As the H500 ridge begins to deamplify and shift eastward late in the week and into the weekend, the region will transition into a tropically influenced weak flow with weaker subsidence. This pattern shift will allow for more numerous shower and thunderstorm activity to return to the forecast area, offering localized relief from the oppressive heat, but also potentially affecting celebrations for the holiday weekend. Details remain murky given the weak flow regime. && .AVIATION /09Z MONDAY THROUGH FRIDAY/... Observations this morning show IFR to LIFR conditions across all terminals in fog and low stratus. Conditions will improve to VFR across all terminals through 13Z. More fog is possible tonight, although coverage should be less than this morning. For the remainder of the period, diurnal cumulus will develop under daytime heating, with generally light winds expected. Isolated showers and thunderstorms may initiate over the mountains this afternoon, but confidence in direct terminal impacts is too low to in the EKN/BKW forecasts at this time. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: Timing of dissipation of fog may vary this morning. Isolated showers/thunderstorms could approach EKN/BKW this afternoon. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE MON 06/29/26 UTC 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18 EDT 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14 CRW CONSISTENCY L M M M M L L H M M M H HTS CONSISTENCY M L L L L M M M M M M H BKW CONSISTENCY L L L L L L M M M M M M EKN CONSISTENCY L M M M H H H M M H M H PKB CONSISTENCY L M M H H H M H M M M H CKB CONSISTENCY M M M M M L L H H M M H AFTER 12Z TUESDAY... IFR will be possible in early morning fog Tuesday morning. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ DISCUSSION...JP AVIATION...JP