050117 Forecast

Mountain Area Forecast ( May 1-3 )

ALERT For Strong SSW-W Winds Through Monday

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