... Warm conditions will linger through Thursday, south of a weak stationary front. A strong cold front will cross our area from the northwest on Thursday, with cooler high pressure spreading over the region for Friday and Saturday. Low pressure with abundant moisture could affect our region on Sunday and Monday.
NEAR TERM /THROUGH WEDNESDAY/... As of 1025 PM Tuesday: Quiet weather continues under flat ridging aloft tonight. We may see an uptick in shower activity near sunrise across the mountains as low level flow veers from the west to northwest for enhanced upslope flow coupled with additional lift from a weakening boundary. Overnight lows are expected to be in the 50s to near 60 coolest across northern areas where some clearing of clouds is expected.
Otherwise, atmosphere expected to become moderately unstable Wednesday as the low levels remain very warm and moist. There may be a small cap early that erodes during the afternoon. Deep layer shear will be strong once again. Outflow boundary from overnight MCS activity to our north may drop south into the piedmont to help provide some organization. This would increase the potential for severe storms; however, boundary location and timing is more uncertain than the instability or shear. SPC has the entire forecast area in a Marginal risk, and that looks appropriate. Still, overall coverage looks to be isolated to low end scattered for the afternoon. Highs will be around 15 degrees above normal.
SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... As of 1230 PM EDT Tuesday: Eyes will be shifting west of the mountains Wednesday night as a moderately forced cold front is progged to trigger numerous showers and possibly svr thunderstorms. The mean flow and deep layer shear would promote deep convective activity making a run at the NC mountains overnight. Inherited sensible wx featuring numerous coverage throughout the Tennessee border counties looks to be on track. Deep convection, or remnants thereof, should translate quickly acrs the mountains Thursday morning with the model consensus still suggesting a very low potential for convection making it into the foothills. Initial influx of cooler air in the wake of the cold front will be offset by downslope flow and the April sunshine, maintaining the above normal readings. A cooler and mixed environment is expected Thursday night within the broad cyclonic flow with daybreak Friday minimums back to near the seasonal normals. The broad and dry WNW flow lingers through Friday with some southern stream energy rippling by to our south. Our spell of above normal warmth will come to an end with Friday's fcst max temperatures about 5 deg F below climo.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... As of 100 PM EDT Tuesday: Cool sfc ridging should be atop the region to start off the period and frosty temperatures are forecast for the NC foothills/piedmont during the pre-dawn hours Saturday. Model consensus commences a top down moistening throughout the day on Saturday as the mean flow backs and begins to tap developing southern stream moisture. Under filtered sunshine, temperatures will warm a tad back closer to climo. Model mass fields are showing the best larger scale lift and moisture still centered on Easter Sunday, resulting in rainfall becoming widespread. Given it is April and how dynamic looking this system appears, both excessive rainfall and/or svr wx cannot be ruled out. Precip chances tail off at some point Monday and a small chance of showers was maintained for Tuesday's follow-up wave as seen in the 00Z ECMWF.