|Dew Point:||28.8°F (-1.8°C)|
|Sea Level Pressure:|
Freezing RainHigh: 30 Low: 29
Freezing Rain LikelyHigh: 35 Low: 22
Slight Chance Freezing Rain then Partly SunnyHigh: 32 Low: 29
Slight Chance Freezing RainHigh: 47 Low: 35
Chance Rain ShowersHigh: 52 Low: 44
Freezing rain and patchy fog. Cloudy, with a high near 30. South wind around 14 mph, with gusts as high as 22 mph. Chance of precipitation is 90%. New ice accumulation of less than half an inch possible.
Freezing rain before 7pm, then freezing rain and patchy fog. Cloudy, with a low around 29. South wind 3 to 15 mph, with gusts as high as 23 mph. Chance of precipitation is 100%. New ice accumulation of less than half an inch possible.
Freezing rain likely and patchy fog. Cloudy, with a high near 35. Southeast wind 3 to 13 mph. Chance of precipitation is 70%. Little or no ice accumulation expected.
A chance of freezing rain. Cloudy, with a low around 22. Southeast wind 12 to 16 mph, with gusts as high as 25 mph. Chance of precipitation is 30%. Little or no ice accumulation expected.
A slight chance of freezing rain before 6am. Partly sunny, with a high near 32. Southeast wind 13 to 17 mph, with gusts as high as 25 mph. Chance of precipitation is 20%.
A slight chance of freezing rain after midnight. Mostly cloudy, with a low around 29. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.
A slight chance of freezing rain before 9am, then a slight chance of freezing rain and a slight chance of rain between 9am and 5pm. Mostly cloudy, with a high near 47.
Mostly cloudy, with a low around 35.
A chance of rain showers after 8am. Mostly cloudy, with a high near 52. Chance of precipitation is 50%.
... Low pressure to our west will move along a warm front located just south of the forecast area through Sunday. This will bring a wintry mix to the northern mountains and cold light rain elsewhere. Well below normal temperatures will persist through Tuesday as strong high pressure builds down the Appalachians. Temperatures warm back to near normal for late week as high pressure moves offshore and moisture increases ahead of the next cold front.
NEAR TERM /THROUGH SUNDAY/... As of 240 pm Saturday: Warm front currently extends from surface low across southeast Missouri, across northern Middle TN into southeast TN/north GA and the SC Piedmont. Areas of showers continue to develop north of the boundary, and this is expected to continue into through the afternoon and evening, as the surface low continues to scoot E/SE. Web cams suggest a warm nose is trying to develop across the NC mountains from the southwest, as web cams across the high elevations of the southern and central mtns (where air temps remain in the mid/upper 30s) are indicating liquid precip. Even some of the northern mtn cams seem to indicate some degree of mixture is occurring. The forecast has been initiated across the northern mountains with a mix of snow/sleet/fzra before a transition to all fzra by early evening. Temps and qpf are the main area of uncertainty, and unfortunately the degree of weather impacts depends greatly on these two parameters this evening. The cold air will become increasingly confined to areas along the eastern escarpment this evening into the overnight, as (initially in-situ, but increasingly strong hybrid) cold air damming becomes the primary mechanism for sustaining cold air. What's not clear at all is whether the CAD will be strong enough to hold in the cold air this evening, when the higher precip rates are anticipated. Factors that would argue for keeping the cold air locked in: persistent /slightly increasing upslope flow and in-situ cold air damming. Factors that would tend to dislodge the cold air: absence of light precip this afternoon, latent heat release due to freezing once the heavier rainfall rates develop this evening.
Meanwhile, chances for convection are also expected to increase in the vicinity of the warm front later this afternoon and evening. SPC mesoanalysis depict a nice elevated mixed layer from the lower Miss into the TN Valley, where mid-level lapse rates of 7 to 8 C/km were analyzed at 18Z. This plume will continue to spread E/NE through the day, yielding some respectable values of muCAPE (500-1000 J/kg) intersecting the warm front ahead of the surface low. We have continued a slight chance of thunder across the NC mtns this evening. However, the larger concern will be the precip rates associated with said showers/embedded TSRA and potential interaction with the cold air over the eastern escarpment. We continue to advertise ice accums of .1 to .5 inch across the eastern escarpment, but confidence in this is moderate at best.
Another issue is the potential for snow to develop outside the mtns, mainly along and north of the I-40 corridor this evening, as potentially heavy showers spread out over an area with surface temps in the mid/upper 30s, and the absence of a warm nose per the latest forecast soundings. High enough precip rates could force periods of a transition to snow, or at least a rain/snow mix, but this is quite uncertain, and I would not anticipate anything more than spotty dustings if it does occur. All that being said, the only planned changes to the current advisory will be to downgrade the high elevations of Buncombe County to an advisory.
Otherwise, heavier precip will taper off into the early part of the overnight, with all locations receiving a categorical pop in the interim. Min temps will be in the mid/upper 30s across much of the area. Hybrid cold air damming will persist into Sunday, yielding areas of drizzly/-RA conditions, with lingering potential for light ice accums along the northern Blue Ridge. Max temps are forecast to be about 20 degrees below climo.
SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... As of 220 PM Sat: A sharp upper ridge extending from the central Gulf states north into eastern Canada will permit a strong sfc high to strengthen down the Eastern Seaboard Sunday night into Monday, reinforcing cold-air damming over our CWFA. As earlier shifts also have noted, this wedge is quite a bit stronger than the past few we have experienced. It will bring sufficiently strong subsidence to promote low-level drying early Monday. Precip chances will diminish overall, though southeasterly 850mb flow will maintain upslope forcing against the Blue Ridge. The remaining moisture will be concentrated near the surface, where temperatures aloft will be too warm for ice nucleation. Accordingly we will advertise small chances for either rain or freezing rain, dependent on surface temp. Model QPF is small and any ice accumulation would be mainly at high elevations, and impactful only on travel. The temp fcst for Monday is somewhat tricky, with some sources (particularly NAM) reflecting much more of a CAD effect than others. Given limited precip, split the difference and went with a blend of raw guidance, which still keeps most of the area in the 40s.
The ridge axis tilts Monday night which will lead to slightly more divergent upper flow over the area for Tuesday, so gradual breakdown of the CAD should get underway. Meanwhile upstream, advancing low pressure over the Midwest begins to pull Gulf moisture into the lower Mississippi Valley. In response, low-level flow will turn southerly again over our area and deeper moisture will return. PoPs increase slowly once again Monday night and remain elevated Tuesday; though they are relatively low, the Blue Ridge again gets the focus for the highest values. The deeper moisture does saturate the levels where ice nucleation can occur, but a strong warm nose is expected to melt any snowflakes completely, resulting in freezing rain chances once again where sfc temps are below freezing. Per Bourgouin technique, even if evaporative cooling reduces the depth of the warm nose, FZRA still looks to be the primary p-type. Again, current model QPF generally is pretty small so it does not look like any more than advisory icing early Tuesday. Temps will warm up into the upper 40s in our northern areas Tue aftn, with lower to mid 50s in the south.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... As of 230 PM Saturday: Mid level ridging will be in place across the area on Tuesday night and Wednesday while surface high pressure will be centered off the southeast coast. Some showers associated with a cold front across the Ohio Valley will impact the mountains on Wednesday while the rest of the forecast area remains dry and warms up in the southerly flow. The mid level high will flatten out by Thursday allowing the front to approach the area leading to more widespread shower activity Thursday afternoon through Friday. This system will push east of the area by Friday night with high pressure building in for next weekend.
The main hazardous weather potential in the extended period will be heavy rainfall. WPC and model data at this point suggest that 1-3 inches of rain is likely, but that the system will likely progress quickly enough to prevent excessive rainfall. Will continue to monitor.