... A cold front will cross our area from the west this evening bringing drier air. Seasonally cool and dry conditions will persist over the weekend. Expect two rather weak systems to bring some precipitation at the start of the week and again in mid week. There is the potential for a much stronger weather system at the end of next week.
NEAR TERM /THROUGH SATURDAY/... As of 440 PM: The main late afternoon adjustment to the forecast will be to boost thunder chances east of I-77, particularly over Union Co. NC. In that area, late day SHERB index values depicts some spotty values above 1.0, which is statistically significant for organized shallow severe linear convection. The PoP gradient will be sharpened up as well across the eastern parts, and cloudiness maintained a bit longer throughout as low stratus settles in just behind the departing shower/rain shield.
Otherwise, a vertically stacked, occluded low will gradually pinwheel from its currently location over the Midwest into the Great Lakes through Saturday. This will drive the slow moving cold front through the region this evening, with southeast winds gusty at times ahead of the front becoming west to northwest with gusts mainly confined into the mountains tonight into Saturday. Rain, heavy at times, will precede the front with little if any additional hydro concerns. Instability will remain low at best across the I-77 corridor. Isolated to scattered thunderstorms will be possible early this evening and with strong shear at low levels, can't rule out a few stronger storms, if they are able to materialize, east of I-77. Marginal temperatures, moisture, and orographic lift combined with decent upper support may support snow showers at times across the mountains near the Tennessee border later tonight into Saturday. Little to no accumulation is anticipated at this time. Lows will be a bit above normal tonight, especially east of the mountains with near to below normal temperatures for Saturday. Patchy fog is possible tonight east of the mountains (focused across the foothills) due to lingering low level moisture.
SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... As of 235 PM Friday: the short-term forecast picks up at 00z on Sunday with upper trofing lifting north of the fcst area and nearly zonal flow setting up over the region in its wake. This will be short-lived as another upper trof amplifies to our NW and moves over the fcst area on Monday. At the sfc, light return-flow snow flurries will likely linger over the higher peaks and along the North Carolina/Tenn Border thru early Sunday. Otherwise, dry and breezy conditions will continue thru most of Sunday. On Monday, a broad area of deeper moisture will move over the region from the west as a weak low tracks eastward over the Gulf of Mexico. This moist airmass still looks fairly transitory and is expected to move east of the area by late Monday as the period ends. The NW flow snow period is still expected to persist thru most of the period, however total snow amounts haven't changed much from the previous fcst. Most locations can expect an inch or less of snow thru the period, with some isolated 1 to 2 inches likely along the NC/Tenn Border and some of the higher peaks. In addition, wind speeds should remain below Advisory levels thru the period. Temps are expected to be near normal, or slightly above, both days.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... As of 225 PM Friday: the extended fcst picks up at 00z on Tuesday with broad upper trofing moving off the Atlantic Coast and the upper pattern flattening briefly. Late Tues/early Wed, the long-range models have a southern stream upper trof digging down across the ArkLaTex region and approaching our area. The trof still appears to deamplify (to some degree) and lift northward as it reaches our fcst area. Heights recover on Thurs as the trof moves offshore and weak upper ridging builds back over the area. At the surface, broad high pressure will be spreading over the area as the period begins. It will linger over the area thru Tues before another weak low tries to develop over the Northern Gulf Coast and track eastward. Model consistency remains poor wrt this system, with the ECMWF barely developing a discernible low at all. It does move a plume of deeper moisture over the region on Wed while the GFS and CMC models keep the low just to our south before moving it out over the Atlantic. The models do generally agree that things should dry out on Thurs with another low possibly developing by the very end of the period on Friday. I kept the solid chance PoP across the CWFA for Wed, with just a slight chance for Thursday. PoPs increase again for Friday as the next system develops to our south. Temperatures are expected to remain just above normal thru the period.