A much cooler, autumnal air mass will be felt in coming days with chilly nights in mountain valleys ( and by day at high elevations ). While most places will drop into the range of upper 40s to middle 50s, colder mountain valleys at upper elevations will drop into the 40-45 degree range from the High Knob Massif to Burkes Garden. Cool nights are expected to continue into this weekend.
Overnight Into Wednesday Morning
Showers & thunderstorms into the early-mid overnight, local downpours likely, before tapering to showers. Winds SW 5 to 15 mph, with higher gusts, shifting northerly and decreasing into morning. Areas of dense fog, especially at highest elevations ( orographic clouds ). Temps widespread in the 60s ( dropping to around 60 degrees high elevations ).
Wednesday Morning Through The Afternoon
Any showers ending by mid-morning to mid-day, then becoming partly cloudy. Cooler. NNW-N winds 5-10 mph. Temps varying from low-mid 60s at highest elevations to the low-middle 70s ( warmer south into the Great Valley ).
Wednesday Night Into Thursday Morning
Becoming clear and chilly. Areas of dense valley fog. Winds NW-N at 5-10 mph on mid-upper elevation mountain ridges. Temperatures widespread in the 50s, except mid-upper 40s to lower 50s in upper elevations.
Thursday Afternoon
Partly cloudy. Beautiful blue skies. NW-N winds 5-10 mph, with some higher gusts along higher ridges. Temperatures varying from upper 50s to lower 60s at highest elevations to the upper 60s to lower 70s ( warmer into the Great Valley ).
Thursday Night Into Friday Morning
Clear & chilly. Areas of dense valley fog. Light N-NE winds along mid-upper elevation mountain ridges. Large vertical temperature spread between colder valleys-exposed ridges. Temperatures in the upper 40s to middle 50s, except 39 to 44 degrees in colder valleys above 2700-3000 feet.
Friday Afternoon
Partly to mostly sunny. Seasonably cool. N-NE winds 5 to 10 mph. Temperatures varying from low-mid 60s in upper elevations to the lower-middle 70s ( warmer south into the Great Valley ).
Friday Night Into Saturday Morning
Mostly clear & chilly. Areas of dense valley fog. Light NE to ENE winds along mid-upper elevation ridges. Large vertical temperature spread between colder valleys-exposed ridges. Temperatures in the upper 40s to middle 50s, except 40 to 45 degrees in colder valleys above 2700-3000 feet.
The inland track of remnant moisture from tropical activity in the Gulf of Mexico is being monitored for later next week. Stay tuned for updates.
A strong early autumn-like cold front is expected to bring a refreshing air mass change to the mountain region through coming days. While this will be notable at high elevations even during the day, it will be especially noticed during the night-time periods in mountain valleys.
Nocturnal dense fog formation will be likely in lower elevation valleys, especially along streams & rivers, with released latent heat of condensation helping keep temps milder ( upper 40s to lower 50s ) than locations with valley floors above 2700 to 3000 feet where lower dewpoints will enhance cold air drainage.
European 51-Member Ensemble Mean 850 MB Temp Anomalies: Days 1-5
A very strong cool signal is indicated for the next 5 days. While below average temperatures are likely to continue into the 6-10 day period, there is increasing uncertainty, due mainly to tropical activity over the Gulf of Mexico, regarding mid-late next week ( Aug 30-Sept 2 ).
European 51-Member Ensemble Mean 850 MB Temp Anomalies: Days 6-10
The strength and position of a trough over the eastern USA will play an important role in the eventual inland move-ment of tropical moisture over the Gulf of Mexico.
European 51-Member Ensemble Mean 500 MB Height Anomalies: Days 6-10
