Marine Weather and Tide Forecast for Grundy, VA

KEY MESSAGES
1) Extreme heat is expected this week with afternoon temperatures reaching the lower 90s in the mountains and the middle to upper 90s in the lowlands. Heat index values will reach the upper 90s to lower 100s area-wide.

2) No washouts are anticipated this week. Isolated downpours are expected again this afternoon, Monday afternoon in the mountains, and potentially again next weekend.

DISCUSSION
KEY MESSAGE 1...

A large dome of high pressure will expand and build into the middle Ohio Valley beginning Monday afternoon. This will flip a switch from the cooler temperatures seen over the past several days to highs in the upper 80s to lower 90s area-wide by Monday afternoon. High pressure will continue to build and center itself over the middle Ohio Valley and mid-Atlantic region during the middle of the week, with progressively rising temperatures each day.

Given that dew points will be in the upper 60s to lower 70s each day, heat index values are expected to range from 100 to potentially as high as 107 west of the mountain ridges from Tuesday onward. In addition, little relief from the heat is expected during the overnight hours with lows expected to be from 70 to 75 degrees.

Given that this may be a long-duration extreme heat event, which is also occurring during a holiday week, heat safety will be extremely important. Drinking plenty of fluids, taking breaks in the air conditioning, and frequently checking on neighbors and family will be vital this week. In addition, applying sunscreen will also be very important for anyone spending extended time outdoors.

KEY MESSAGE 2...

The combination of surface moisture, a nearby stationary front, and weak energy aloft will trigger isolated downpours today with the highest chances being across northern West Virginia and in the mountains. Given the high PWAT air (~1.75in) and a saturated ground from recent rainfall, there will be an isolated flooding risk across these areas later today. The Weather Prediction Center has placed portions of northern West Virginia in a Slight Risk of excessive rainfall today. This potential for isolated showers and thunderstorms will return Monday across the mountains.

As high pressure expands from Tuesday onward, an extended period of dry weather will build into the region. Models show that the ridge of high pressure may slightly break down next Saturday and Sunday, which could allow for a few weak disturbances to cross and trigger afternoon thunderstorms. Due to uncertainty, PoPs will be limited to 20 to 40 percent for now.

AVIATION /00Z MONDAY THROUGH FRIDAY/

Showers will tapper off this evening. Expect dense fog to form overnight in areas receiving rainfall today and in the river valleys. After the fog lifts Monday morning, expect mainly VFR conditions with some cumulus. The exception would be with some scattered showers and thunderstorms during the afternoon in the northern and central mountains.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY...

FORECAST CONFIDENCE: Medium.

ALTERNATE SCENARIOS: Timing of fog tonight could vary.

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.

UTC 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09 EDT 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 CRW CONSISTENCY H H H H H H H L M M M M HTS CONSISTENCY H H H H H H H L M M M M BKW CONSISTENCY H H H H H H H H L M M H EKN CONSISTENCY M H H H H L H L H H H H PKB CONSISTENCY H H H H H H H L M M M M CKB CONSISTENCY H H H H H H H L M M M M

AFTER 00Z TUESDAY...
IFR will be possible in early morning fog Tuesday morning.

RLX WATCHES/WARNINGS/ADVISORIES
WV...None.
OH...None.
KY...None.
VA...None.