Frost Formation Is Expected In Colder Mountain Valleys Into Tuesday Morning. Heavy Frost With A Hard Freeze Will Occur In The Colder Valleys Into Wednesday Morning.
Strong ( Roaring ) SW Winds Are Expected To Develop Wednesday Night Into Thursday Morning Across Mid To Upper Elevation Mountain Ridges-Plateaus.
Overnight Into Tuesday Morning
Clear & colder. Frost developing in colder mountain valleys. Areas of fog along main rivers, lakes, and wetlands. Winds NNW-NE at 5-10 mph, with some higher gusts, along middle to upper elevation mountain ridges. Temperatures varying from upper 20s to lower 30s in colder valleys of the upper elevations to the middle 30s to around 40 degrees.
Partly-mostly sunny ( some high clouds possible ). Light NE-ENE winds. Temperatures varying from upper 40s to lower 50s in the upper elevations to upper 50s to lower to middle 60s ( warmer south into the Great Valley ).
Tuesday Night Into Wednesday Morning
Mostly clear. Cold. Large vertical temperature spread between frosty valleys and exposed ridges. Hard freeze within the colder valleys. Winds SSE-SSW 5-10 mph, with higher gusts, on mid-upper elevation ridges. Temps from lower-middle 20s in colder valleys of upper elevations to the upper 30s to lower 40s on exposed ridges.
Mostly sunny. Winds SSW-SW 5-15 mph, with higher gusts on mountain ridges. Temperatures varying from upper 50s to lower 60s in upper elevations to upper 60s to lower 70s.
Wednesday Night Into Thursday Morning
Becoming cloudy & windy. Chance of a sprinkle or shower by morning. SSW-SW winds increasing to 10-20 mph, with higher gusts, along mountain ridges-plateaus below 2700 feet. Winds SW to WSW at 15-25 mph, with higher gusts, along mountain ridges above 2700 feet. Temperatures in the 40s to lower 50s in valleys to the mid-upper 50s on exposed ridges-plateaus.
Partly-mostly cloudy. Warm. Chance of sprinkles or a shower. Winds SW-WSW 5-15 mph, with higher gusts. Temperatures varying from upper 50s to lower 60s in upper elevations to the upper 60s to lower 70s.
Weather Discussion ( Typical October )
A more typical October weather pattern has been ruling the mountain landscape in recent days, following anomalously warm conditions last week.
It is beginning to look like late autumn-early winter on high valley floors in the High Knob Massif where a hard weekend freeze occurred ( with the first snowflakes of the season at the summit level around High Knob ).
Some 12-13 consecutive hours at or below freezing were recorded during October 22-23 on high valley floors ( from around 9:30 PM on October 22 to after 10:00 AM on October 23 ). This generated a hard freeze due to the long duration ( 9-10 hours in upper 20s ).
Colder valleys in lower-middle elevations also had a rather long sub-freezing period, with 6.5 hours at or below 32 degrees being recorded at the official Clintwood 1 W NWS Cooperative site.
Dry air advection, especially in the 925-850 MB level, will be key to cold nights into Tuesday-Wednesday mornings in the mountain valleys. Especially those in terrain high enough to tap into the really dry air. This is the driest, lowest Td or dewpoint air of the season to date.
Temperatures at 12:30 AM Tuesday were in the mid 30s to low 40s in valleys and the dry air had not yet even come into place ( with strongest advection expected into the predawn-morning hours of Tuesday. This will set the stage for coldest conditions, with rapid temperature drops, Tuesday night into Wednesday morning ).
Strong winds are expected to begin developing at high elevations in the Cumberland Mountains late Wednesday, ahead of the next cold front, with ROARING SW speeds by Wednesday Night into Thursday Morning.
Although orographic forcing will be good, moisture will be limited such that rainfall amounts will likely not be as great as the 0.50″ to 1.00″+ amounts observed with the previous cold front.
The MEAN of the 51-Member European Ensemble group is forecasting a return to anomalous warmth to end October and open up November. However, with significant cold air building at high latitudes over increasing snowpack this new month is not likely to follow the trend of October.