A Heavy Rainfall And Thundestorm Cluster Setup Is Being Monitored For Thursday Night Through Friday Night Into Saturday Morning.
Former ALERTS:
ALERT For Frost & Freezing Conditions In Colder Mountain Valleys Into Monday Morning
Low temperatures will drop into the 30s within many mountain valleys overnight into Monday morning, with upper 30s to lower 40s on exposed middle-upper elevation mountain ridges-plateaus. The coldest mountain valleys will drop into the 20s to lower 30s, mainly at elevations above 2000 to 3000 feet.
Overnight Into Monday Morning
Becoming clear. Chilly. NW winds 5-15 mph, with higher gusts, on middle-upper elevation mountain ridges. Light valley winds. Areas of frost, most widespread in the colder, sheltered valleys. Temperatures varying from 20s to lower 30s in colder valleys ( at mid-upper elevations ) to the upper 30s to lower 40s ( exposed mountain ridges ).
Monday Afternoon
Mostly sunny ( beautiful blue skies ). Milder. WNW to NW winds 5-15 mph, with higher gusts. Temperatures varying from 50s in upper elevations to the lower-middle 60s.
Monday Night Into Tuesday Morning
Partly to mostly clear during the evening, then increasing clouds with a chance of showers-thunderstorms overnight into morning. Rapid evening temp drop in valleys before rising overnight. NW-W winds 5-15 mph, with higher gusts, on middle-upper elevation mountain ridges. Temperatures varying from 30s to lower 40s in coldest valleys ( before rising ) to the 40s to lower 50s.
Tuesday Afternoon
Partly to mostly cloudy. Warmer A chance of showers and thunderstorms. Winds WSW to WNW at 10-20 mph, with higher gusts. Temps varying from the 60s to lower 70s.
Tuesday Night Into Wednesday
Partly to mostly cloudy. Mild. A chance of showers and thunderstorms. Winds WSW-WNW at 10-20 mph, with higher gusts on mid-upper elevation mountain ridges- plateaus. Temperatures widespread in the 50s to lower-middle 60s.
Wednesday Afternoon
Partly cloudy. Warm. A slight chance of a hit-miss shower or thunderstorm. Winds SW-WNW at 5-15 mph, with higher gusts. Temperatures varying from upper 60s to lower 70s at highest elevations to the upper 70s to lower 80s.
Weather Discussion ( Unsettled )
Monday Evening Update
A frosty morning greeted colder mountain valleys with low temperatures varying from the upper 20s to the middle 30s.
The low temperature reached 34 degrees in Clintwood.
Big Cherry Wetland Valley Temperature-RH
The coldest low temperature recorded in the area occurred within high valleys of the High Knob Massif, where colder valleys dropped into the upper 20s. The time spent below freezing was limited by abundant clouds into the early overnight, followed by strong predawn temperature drops.
The MEAN low temperature observed at the Big Cherry Wetland Valley 4 site has been 38.4 degrees so far during the month of May.
Previous Discussion
A chilly weekend was observed across the mountains with snow pouring down at the summit level of the High Knob Massif during Saturday. Although generally not sticking, with temps around or above freezing at 4200 feet, such was not the case upon climbing upward in elevation to the very highest summits where up to 7″ of snow depth accumulated on top of Mount LeConte in the Smokies.
Wind chills dropped into the 10s atop the High Knob Massif to put a true wintry feel into the air. Clearing skies by Sunday morning allowed air temperatures to reach the 20s to around 30 degrees.
High Knob Massif Webcam – University Of Virginia’s College At Wise
A milder but gusty Sunday afternoon graced the mountain landscape beneath fair weather cumulus clouds. This sets the stage for a cold night in mountain valleys as winds decrease overnight into morning.
Frost and freezing conditions will occur in colder locations versus a frost-free environment across exposed mid-upper elevations and the warmer valleys. If you are uncertain about your location, it would be best to bring any tender plants not already in the ground inside for the night.
NAM 12 KM Model Total Rainfall Forecast NEXT 60 Hours
The focus then shifts toward a band of showers and thunderstorms that will be developing amid isentropic lifting along and northeast of a warm frontal zone by Tuesday into Wednesday. The European Model group forecasts the heaviest rainfall corridor to set up from southern Ohio across central-southern West Virginia, northeast of the higher mountain terrain of the famed Mountain Empire. Climatologically, this is favored but until it actually develops the exact corridor for heavy rainfall and thunderstorms can not be certain. Thus, a heavy rainfall and thunderstorm cluster setup is being monitored ( as noted in my headlines at the top ).
European 51-Member Ensemble MEAN 500 MB Height Anomalies Forecast
In general the pattern will be unsettled and cooler than average for this time of year, especially from late week into early next week. The 51-Member European Ensemble MEAN is forecasting a general 2.00″ to 5.00″ of rainfall along the southern-central Appalachians during the next couple of weeks ( through the middle week of May ). Since this is “basin-average” rainfall amounts, during the convective season this means the potential for locally higher totals will have to be respected.
