... A weak low pressure system will cross Florida late Wednesday and Wednesday night, giving our area a chance for precipitation. Brief drying occurs again Thursday. Low pressure develops again to our south on Friday, bringing a chance of rain late Friday and early Saturday.
NEAR TERM /THROUGH WEDNESDAY/... As of 215 PM Tuesday: skies are mostly clear with some lingering stratocumulus over the Northern NC mtns and some patchy high cirrus elsewhere. Winds remain light and generally out of the north to northwest with some stronger values over the higher terrain.
Otherwise, the low-amplitude upper trof will continue to gradually move farther east and offshore, as heights briefly recover tonight and early tomorrow. At the same time, another southern stream upper trof will move across the deep south and towards our area. By the end of the near-term period, the trof axis is expected to be just to our west and providing some degree of upper-lvl divergence over the CWFA. At the sfc, weak high pressure will linger over the area for most of the period keeping things dry and seasonal. Tomorrow, a fairly weak low pressure system will move eastward along the Northern Gulf Coast and towards Florida. By the end of the period 00z Thursday, the low is expected to be centered due south of our area with deep-lyr moisture over the region. There's a decent chance for some light precip over our western zones after roughly 18z tomorrow with PoPs still capped at slight chance over our eastern zones thru 00z Thurs. Any QPF should be minimal and it should all be liquid. Cloud cover will gradually increase overnight and tomorrow as the low approaches the region from the SW. Expect to see bkn cigs in the low-VFR range by noon or so tomorrow over the western half of the CWFA and bkn to ovc cloud cover over all zones by tomorrow evening. Low temps should remain a few degrees above normal overnight/tomorrow morning, with high temps topping out right around normal tomorrow afternoon.
SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 1228 PM Tuesday...not much change in the new model guidance, with decent consensus noted and the same slow trend toward less of a concern for significant wintry weather over the mtns. A shearing and dampening mid/upper wave in the srn stream is still expected to move past our area Wednesday night with only the weakest of isentropic upglide or upslope flow, thus it continues to look like most all the support for light precip will come from the weak mid/upper forcing. The curious thing is the upper system passing over the Midwest/central Appalachians early Thursday. Ordinarily, this might be expected to really enhance a W/NW flow precip event along the TN border, but in this case the W/NW upslope flow is nearly nonexistent. That as much as anything will keep the precip amounts in check and thus keep us from needing a high elevation advisory for snow. As for precip type, it very much looks like an elevation-dependent rain v. snow scenario. The new guidance suggests a snow level around 3-3.5k ft, so perhaps a bit more of the mtns might see some snow Wednesday night. We still expect the light precip over the mtns to taper off midday Thursday in the absence of good low level forcing. Thereafter, a quickly progressive upper pattern will carry an upper ridge overhead Thursday night with sfc high pressure ridging down from the north. Think the moisture associated with the next srn stream system will not reach us before daybreak Friday. Min temps will be a category above normal and max temps near normal because of cloud cover.
LONG TERM /FRIDAY THROUGH TUESDAY/... As of 213 PM Tuesday...the medium range still looks progressively busy as the southern stream remains active all the way out past Day 7. We have two weather systems to deal with. The model guidance has been slowly building some consensus with the first system slowly organizing over the nrn Gulf on Friday and then inducing cyclogenesis off the southeast coast Friday night. As it stands right now, this one looks like something of a "near miss" as our access to cold air remains poor, meaning that most locations with the exception of elevations above 5k feet will be rain for almost the entire event. Once the low passes, snow levels will fall and we stand a decent chance of accumulating snow near the TN border in the NW flow. Several inches of snow would not be out of the realm of possibilities on the peaks and ridges above 5k feet, but unless we can conjure up more cold air, the event would me mainly rain. As for the particulars in the fcst, moisture and forcing increase from the S/SW on Friday and then maximize Friday night and Saturday morning as the low slowly develops during its passage. A likely probability over the eastern zones will suffice for the time being. Temps will keep a low diurnal range but supportive of mostly rain/very high elevation snow.
We dry out Sunday morning and then enjoy a fairly high amplitude upper ridge passing overhead early next week. That will support high pressure moving overhead with temps rebounding well above normal for Monday into Tuesday. Meanwhile, the next system may take shape over the srn Plains. The guidance agrees with a broad upper ridge over the wrn Atlantic and upper trof slowly moving out over the Plains Monday night and Tuesday that will keep a warm SW flow aloft. Always hard to pin down the arrival time of deeper moisture and precip in these situations, probably some time late in the fcst period, but suffice to say right now it looks way too warm for anything other than rain, even over the mountains.