Strong-Severe Wind Gusts Recorded With Squall Line
Flatwoods Mountain Mesonet
A severe 70 mph wind gust was recorded just prior to 2:00 AM on April 4 by the Flatwoods Mountain Mesonet, adjacent to Pine Mountain, in extreme southeastern Pike County, Ky., near the Pike-Dickenson County border.
Black Mountain Mesonet
A 52 mph gust, with many gusts at or above 40 mph, was recorded by the Black Mountain Mesonet in Harlan County, Ky., adjacent to the Wise-Harlan line on the VA-KY border.
GOES-16 Image At 2:02 AM on April 4, 2018Lightning Detection With Shortwave IR At 2:02 AM on April 4, 2018
Former Alerts
Severe Thunderstorm Watch Number 34 Is In Effect
Storm Prediction Center Severe Thunderstorm WatchSPC Severe Thunderstorm Watch Statement
ALERT For Strong SW Winds Developing Late Tuesday Into Tuesday Night Well In Advance Of A Squall Line
A strengthening pressure gradient will increase winds across the mountain area Tuesday afternoon into Tuesday night in advance of a developing line of strong to severe thunderstorms forming west of the Appalachians.
Storm Prediction Center Updated Risk Regions Into Early Hours of April 4
Locally strong to severe wind gusts will also be possible along the squall line that should be in a weakening mode as it crosses the mountains after midnight Wednesday, with a sharp temperature drop expected into Wednesday morning.
Frosty cold conditions are expected into Thursday morning.
Overnight Into Tuesday Morning
Cloudy. Areas of dense fog. A chance of scattered rain showers. SW winds 10 to 20 mph, with higher gusts, along mid-upper elevation mountain ridges. Temperatures in the 40s to lower 50s.
Tuesday Afternoon
Partly to mostly cloudy. Chance of hit-miss showers and thunderstorms. Windy. SSW-SW winds 10-20 mph with higher gusts. Temperatures varying from low-mid 60s to low-mid 70s ( coolest at upper elevations ).
Tuesday Night Into Wednesday Morning
Showers & thunderstorms becoming likely, especially overnight. Windy. SSW-SW winds 15-25 mph, with higher gusts, shifting WNW by morning. Turing sharply colder by morning. Evening temperatures in the 50s and 60s, then plunging rapidly into the 30s to low 40s by morning…with upper 20s to around 30 degrees at highest elevations. Wind chills dropping into the 20s & 30s by morning, with 10s in gusts at highest elevations.
Wednesday Morning Through The Afternoon
Morning clouds giving way to partly-mostly cloudy skies. Windy & seasonally cold. WNW-NW winds 10-20 mph with higher gusts. Temperatures varying from 30s in the upper elevations to the 40s at low-middle elevations ( milder lee of the Cumberland-Allegheny Front ).
Wednesday Night Into Thursday Morning
Becoming mostly clear with decreasing NW-N winds. Frosty cold. A hard freeze within mountain valleys. Temperatures falling into the 20s to near 30 degrees, except 10s in colder mountain valleys at upper elevations.
A colder than average weather pattern for this time of year is expected to continue into next week. A system with the potential to produce significant snow is being monitored for this weekend.
Weather Discussion ( Active Pattern )
An active spring weather pattern will continue through coming days, with a notable trend toward colder-than-average conditions for this time of year.
Temperatures held in seasonally chilly 40s to lower 50s through Monday in locations along and north of the High Knob Massif and Tennessee Valley Divide. By Wednesday temperatures will be even colder despite a developing mix of sunshine and clouds.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Although early spring wildflowers are beginning to bloom, especially at lower-middle elevations, a up-and-down temp pattern is typical for this time of year…as is snow.
Yellow Trout Lily ( Erythronium americanum ) – Early Spring 2018
While beginning to show signs, very little is currently blooming at upper elevations in the High Knob Massif where the colder valleys recently dropped into low-mid 10s during March 22 and the lower-middle 20s during March 31 ( the last 0 degree reading occurred in early February ). Another morning with MIN temperatures into the 10s is upcoming into April 5.
Big Cherry Lake of High Knob Massif – March 31, 2018
This forecast period ( April 2-5 ) 31 years ago featured a historic snowstorm during 1987, with a general 2 to 4 FEET of snow depth along and north of the High Knob Massif.
Re-Analysis Chart For April 4, 1987
Carl Henderson, electrical engineer for the Blue Ridge PBS transmitter station on Eagle Knob reported a general 2 to 6 feet of snow depth by the conclusion of this great storm.
Nearly 2000 vertical feet below, in the City of Norton, a snow depth of 3 feet was reported by Gary Hampton at the Norton Water Plant this week in April 1987.
The short-term forecast will focus on increasingly strong winds and the potential of wind damage, locally in pressure gradient driven flow late Tuesday into Tuesday night, then along a squall line of showers-thunderstorms into the over-night and predawn hours of Wednesday.
European 51-Member Ensemble Mean 500 MB Height Anomalies: Days 4-8
While the short-term will focus on a windy, warm surge of air Tuesday ( March 3 ) that will support formation of severe thunderstorms west of the Appalachians by the afternoon, medium range attention quickly shifts to a colder than average pattern that has the chance to generate some significant snowfall by this weekend.
European 51-Member Ensemble Mean 850 MB Temp & Anomalies: Days 4-8
A mean 850 MB temperature around 32 degrees F ( 0 C ) is being forecast by the European Model Ensemble MEAN in the upcoming 4-8 day period during April 6-10. This chilly period begins, as noted in the forecast, by Wednesday AM and features frosty cold 20s by Thursday AM ( with 10s in colder valleys of the High Knob high country ).
While there are signs the pattern may trend milder during the second half of April, up-down temperature fluctuations are likely to continue into May ( as climatology shows ).
