An Alert For Frost & Freezing Conditions May Be Needed Across Much Of The Area By Monday Morning
*Temperatures around or below freezing will be possible on highest peaks into Saturday morning, and in high valleys and peaks on Sunday morning.
Overnight Into Friday Morning
Showers with a chance of thunder. Winds shifting SW to WNW at 5 to 15 mph, with higher gusts. Temperatures dropping into low-mid 40s at highest elevations to the upper 40s to mid 50s. Low clouds ( dense fog ) in upper elevations.
Friday Afternoon
Showers. Low clouds & chilly. Winds SSW-W at 5-15 mph, with higher gusts. Temperatures rising very little or slowly falling in the 40s ( upper elevations ) and middle 50s to lower 60s at middle-lower elevations by late afternoon.
Friday Night Into Saturday Morning
Rain & showers. Turning colder. Rain becoming mixed with or turning to snow at elevations above 3500 feet overnight into morning. WNW to NW winds 10-20 mph, with higher gusts. Temperatures varying from around freezing at highest elevations to low-mid 40s. Wind chill factors within the 20s and 30s, except 10s in gusts on highest summits ( above 3600 feet ). Orographic clouds-dense fog upper elevations ( becoming freezing fog highest peaks ).
Saturday Mid-Morning To Mid-Day
A break possible in showers. Partly to mostly cloudy. Winds WNW-NW 5-15 mph, with higher gusts. Temps in the 30s ( upper elevations ) to the 40s ( low-middle elevations ).
Saturday Afternoon
Low clouds. Showers redeveloping. Rain and/or snow mix on highest peaks. Local small hail possible. Winds WNW-NW at 10-20 mph, with higher gusts. Temps varying from 30s in upper elevations to middle 40s to lower 50s. Dense fog at upper elevations. Wind chills varying from 20s in upper elevations to the 30s to around 40 degrees.
Saturday Night Into Sunday Morning
Low clouds. Showers tapering to drizzle before ending. Clearing possible by morning. Cold. Winds W-NW at 5-15 mph, with some higher gusts. Temperatures varying from 20s to around 30 degrees on highest peaks and high valleys to the upper 30s to around 40 degrees. Wind chills varying from 10s & 20s at highest elevations to the 30s. Dense fog in upper elevations ( freezing fog highest peaks ) giving way to clearing toward morning.
Sunday Afternoon
Mostly sunny ( deep blue ) skies. Gusty & chilly. Winds WNW-NW at 10-20 mph, with higher gusts. Temperatures varying from low-mid 40s at highest elevations to the middle-upper 50s. Wind chills in the 30s and 40s across middle-upper elevation mountain ridges.
Weather Discussion ( Chilly & Wet )
An unseasonably cold, for this time of year, pattern is taking shape for this weekend into much of next week.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Dramatic cloud formations, as often is the case when SE winds blow across the High Knob Massif, were on display throughout much of Thursday ( May 4 ).
A persistent standing wave on the SE flow stood for hour after hour as strong-gusty winds blew upward across the high country. Although changing specific appearance at any given moment, the general cloud formation remained consistent through time.
High Knob Massif Webcam – University Of Virginia’s College At Wise
While below freezing air and even flakes of snow are not uncommon during May, especially in the high country, the upcoming pattern is going to be unseasonably cool during the next 10 days ( in the mean ).
Majestic Spring Afternoon In Big Cherry Wetland Valley – May 3, 2017
Temperatures in the 30s have occurred in high valleys within the High Knob Massif recently during morning hours of April 26 and May 3; however, temperatures in the 20s within high valleys will likely occur by early next week ( perhaps as early as Sunday AM if skies should clear before sunrise ). This is a given.
The more critical forecast will be for lower-middle elevations, even the thermal zone orchard belt, where some frost sensitive crops may already be planted. Stay tuned for updates.
European 51-Member Ensemble MEAN 500 MB Height Anomalies: Days 1-5
The European Model group ensemble MEAN is showing troughing across the eastern USA, with a general Omega Blocking feature that allows the pattern to reload next week just as it appears that warming might take hold.
European 51-Member Ensemble MEAN 500 MB Height Anomalies: Days 6-10
This results in an unseasonably chilly May pattern.
European 51-Member Ensemble MEAN 850 MB Temp Anomalies: Days 1-5
If this forecast verifies, unseasonably cold air for this time of year will continue through the first half of May. Timing when frost and freezing conditions occurs will be the main forecast challenge upcoming.
European 51-Member Ensemble MEAN 850 MB Temp Anomalies: Days 6-10
The Storm Prediction Center Has Issued A Risk For Severe Thunderstorm Development Monday
Storm Prediction Center Risk Regions For Monday – May 1, 2017
*An Enhanced Risk for Severe Thunderstorm Development will exist East to Northeast of the Cumberland Mountains, with the potential for upscale growth into a damaging squall line in locations along and east of the Blue Ridge.
Stay tuned to NOAA Weather Radio and your favorite media sources for any possible watches or warnings that may be issued during Monday.
Overnight Into Monday Morning
Mostly cloudy. Windy & mild with a chance of showers. SSE-SSW winds 5-15 mph, with higher gusts, on mountain ridges-plateaus below 2700 feet. Winds S-SW 10-20 mph, with higher gusts, on mountain ridges above 2700 feet. Temperatures widespread in the 60s.
Monday Morning Through Monday Afternoon
Showers & thunderstorms becoming likely. Some storms could be strong to locally severe. Windy. SW to W winds at 15-25 mph, with higher gusts ( to 40+ mph ). Temperatures varying from low-mid 60s in upper elevations to the lower-middle 70s. Period of low clouds ( dense fog ) at the highest elevations.
Monday Night Into Tuesday Morning
Partly-mostly cloudy skies giving way to mostly clear conditions by morning. Windy. SW-W winds 10-20 mph, with higher gusts, along mid-upper elevation mountain ridges and plateaus. Temperatures varying from low 40s upper elevations to the upper 40s to lower 50 degrees.
Tuesday Afternoon
Partly to mostly sunny ( blue ) skies. Cooler & windy. WSW to W winds 10-20 mph, with higher gusts. Temperatures varying from 50s in upper elevation to 60s to around 70 degrees at lower-middle elevations.
Tuesday Night Into Wednesday Morning
Mostly clear & chilly. Winds shifting NW at 5-15 mph and decreasing toward morning on all but the highest mountain ridges. Temperatures varying from 30s in upper elevations, and the coldest valleys, to the 40s. Areas of river valley fog.
Weather Discussion ( Late Spring )
The arrival of May marks the final month of Meteorological Spring, and a shift into a cooler weather pattern in wake of unseasonable warmth during the second half of April.
Wild Geranium ( Geranium spp. ) On April 27, 2017
April 2017 ended having produced a general 6.00″ to 10.00″ of rain along the Cumberland Mountains.
Swallowtail Butterfly On A Wild Azalea ( Rhododendron periclymenoides )
This wet pattern also looks to continue as temperatures chill downward during the first week or so of May.
European Ensemble MEAN 500 MB Height Anomalies: Days 1-5
The 51-Member European Ensemble MEAN is forecasting a upper air trough to dominate in the mean during the first 10 days of May, with basin average rainfall totals in the 3.00″ to 5.00″ range.
*Localized variations in amounts could be significantly greater, with both lesser and higher precipitation totals being possible during this period.
European Ensemble MEAN 500 MB Height Anomalies: Days 6-10
This results in a rather dramatic shift toward cooler than average temperatures for this time of year.
European Ensemble MEAN 850 MB Temp Anomalies: Days 1-5
Much below average temperatures is currently being forecast during the May 4-10 period.
*Some model runs have actually shown the air cold enough for snow to fall at highest elevations along the central-southern Appalachians. That remains to be seen, of course, but would certainly not be impossible ( i.e., it has occurred many times during past May’s ).
European Ensemble MEAN 850 MB Temp Anomalies: Days 6-10
