|Dew Point:||49.0°F (9.4°C)|
|Sea Level Pressure:||30.41" (1029.7 mb)|
Mostly SunnyHigh: 59 Low: 41
SunnyHigh: 61 Low: 50
Rain Showers LikelyHigh: 59 Low: 34
Patchy Frost then SunnyHigh: 51 Low: 33
Areas Of Frost then SunnyHigh: 53 Low: 39
Mostly sunny, with a high near 59. Southeast wind around 1 mph.
Mostly clear, with a low around 41. Southeast wind around 2 mph.
Sunny, with a high near 61. South southwest wind 2 to 8 mph.
A chance of rain showers after 8pm. Mostly cloudy, with a low around 50. West southwest wind 6 to 10 mph. Chance of precipitation is 50%. New rainfall amounts between a tenth and quarter of an inch possible.
Rain showers likely. Mostly cloudy, with a high near 59. West northwest wind 10 to 14 mph, with gusts as high as 22 mph. Chance of precipitation is 60%.
A chance of rain showers before 8pm, then patchy frost. Partly cloudy, with a low around 34. Chance of precipitation is 30%.
Patchy frost before 7am. Sunny, with a high near 51.
Areas of frost after 5am. Clear, with a low around 33.
Areas of frost before 8am. Sunny, with a high near 53.
... Cool high pressure will move off the mid Atlantic coast on Friday as a cold front approaches from the west. A narrow band of showers crosses our region ahead of the front on Saturday. Much cooler and drier air arrives behind the front Saturday night through Sunday. The dry and cool air will linger into the early part of next week before the weather becomes more unsettled mid-week.
NEAR TERM /THROUGH FRIDAY/... As of 200 PM...A flat upper ridge will shift east across the eastern CONUS tonight thru Friday, allowing a stream of patchy cirrus to stream across the forecast area. Meanwhile, a sfc high will migrate east from the Ohio Valley to the Mid-Atlantic coastal waters. This will result in a little better radiational cooling than last night. The 850 mb flow will turn out of the SW and start some WAA across the NC mountains, which should limit temps from dropping much lower than the upper 30s to lower 40s. So patchy frost looks to be confined to the sheltered valleys in the Northern Mountains. Overall, min temps will be about a category cooler than last night, which is slightly below normal.
Friday, a vigorous upper trough will dive into the Midwest, while the ridge axis reaches the Eastern Seaboard. This will result in flow turning out of the WSW atop the forecast area and should bring in some increasing clouds by the aftn hours, especially across the southern zones. With that said, temps should manage to bounce back to the mid to upper 60s across the lower elevations before clouds thicken up. Dry conditions are expected to continue thru the daylight hours.
SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... As of 245 PM EDT Thursday: The model guidance has backed off with the time of arrival of a moisture plume from the western Gulf and mid/upper forcing topping a flat upper ridge across the southeast on Friday evening, altho they agree that onset will be fairly quick when it happens. The initial forcing moves in after sunset Friday, mainly over the mtns, while the deeper moisture moves in after midnight. Have pushed back the onset to Saturday morning, which effectively lowers the precip prob east of the Blue Ridge. Overnight temps should be relatively mild. The latest guidance moves a strung-out vort lobe across the region thru midday Saturday with enough dpva and upper divergence to support a likely precip prob at least across NC. However, the westerly flow at low levels will be less supportive across the Upstate and northeast Georgia, so we have limited the prob to a chance in those areas. Instability will be almost nil so thunder was omitted. The system will be a fast mover so precip probs shift east quickly and pare back to the mtns by the end of the day. The fcst gets somewhat interesting Saturday night and early Sunday morning as the first shot of what you might call cold air moves in behind the cold front. Residual low level moisture should support some upslope precip along the TN border after sunset as the flow veers around to nnw. However, the new model guidance has shallower moisture and is not as supportive of precip as previous runs have been. The cooler mid-level air, that is to say, more supportive of snow showers, looks like it will miss to the N across the Virginias early Sunday morning. So, we might be left with a changeover to brief snow showers in some places before precip ends, or maybe even just a few flurries. However, this will serve as a reminder that winter is no longer far away. Temps will drop enough across the nrn mountains that an advective freeze is possible. Outside the mtns, temps and wind will probably remain high enough to prevent frost, but it will still be our first cold autumn morning on Sunday. High pressure moves in from the nw on Sunday with clearing sky, but temps at least ten degrees below normal.
LONG TERM /MONDAY THROUGH THURSDAY/... As of 220 PM EDT Thursday: No change from earlier thinking with regard to the fairly high potential of our first widespread frost/freeze of the season on Sunday night/early Monday morning. The latest GFS moves the center of a large continental sfc high over nw NC at 12Z Monday, setting up ideal radiational cooling conditions. The guidance has lowered the min temp just a bit. Will probably need a Freeze Watch issued tomorrow to raise awareness of the potential.
Overall, the medium range looks like mostly a period of tranquil autumn weather, at least through mid-week. A flat upper ridge will carry the sfc high on Monday, but a dry cold front will move thru possibly Tuesday to reinforce the high pressure thru Wednesday. Beyond that time, significant model differences raise the uncertainty with a srn stream system that may approach Wednesday night and Thursday. The latest GFS has shown poor continuity with this system and would now suggest that precip arrival would be delayed until Thurs nite. The ECMWF was slower and more amplified with upper features, but that allowed moisture to return quicker with precip developing Wednesday night. The new fcst follows the ECMWF more closely but keeps precip prob in the chance range and temps below normal.