... Cool temperatures and dry conditions will round out the weekend, with multiple rounds of rain returning for the next week. Another cold front approaches the area by late next week. Temperatures will be cooler early on and begin to warm by the middle of next week.
NEAR TERM /THROUGH TONIGHT/... As of 1000 AM: Minor tweaks to temps/dewpoints/sky this update per latest obs. The extent of dense fog declined greatly between 9 and 10 AM, with Franklin Co Arpt the only site remaining at 1/4SM. Allowed Dense Fog Advy to expire. Expect heights to fall a little today as a weak short wave moves by to our north. The center of surface high pressure moves into the central Appalachians with the pressure gradient relaxing over our area. Still expect quite a bit of jet stream and mountain wave cirrus will remain over the area today in the northwesterly mid and upper level flow, so only filtered sunshine expected. Thickness values will be lower as well. Though updated values are a tad warmer in spots, still expecting highs near normal across the mountains and up to 5 degrees below normal over the NC foothills and Piedmont and eastern Upstate where the cirrus will be thicker. Highs will be near to slightly below normal elsewhere.
Northwest flow aloft continues tonight as the center of surface high pressure moves into the VA Piedmont. The jet stream and mountain wave cirrus will continue at least into the evening. Guidance does show it dissipating overnight. Clouds will increase from the southwest after midnight as the next weather system approaches. The clouds will likely limit the potentially good radiational cooling, at least initially over NC and later over NE GA and the Upstate. Therefore, expect quite a gradient in low temps tonight. Lower 40s over NE GA dropping as low as the upper 20s across the northern NC mountains and I-40 corridor.
SHORT TERM /MONDAY THROUGH WEDNESDAY/... As of 245 AM Sunday: A wetter pattern will begin for the week as surface high pressure migrates eastward in the southern CONUS on Monday. Meanwhile, an area of upper high pressure continues to churn over the Gulf of Mexico, with upper level flow remaining predominately zonal to the north. Surface southwesterly flow returns moisture to the region, as upper air profiles saturate through the forecast period. A weak shortwave should pass through the area on Monday afternoon and provide enough lift for precipitation, hence PoPs increase from the west and spread across the CWA throughout the day and into Tuesday and Wednesday. Heaviest rainfall is expected to remain over the western Carolina mountains. Therefore, included categorical PoPs on Monday night to the west and becoming more widespread Tuesday. Given the minimal instability, showers are expected to remain mostly non-convective. Temperatures during this forecast period are expected to be closer to normal on Monday, in the majority of the Piedmont and mountains. On Tuesday, temperatures should begin warming and be slightly above normal. Cloud cover should keep nightly temperatures above normal during this time.
LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... As of 245 AM Sunday: As a continuation from the short term, this forecast period remains rather wet for the majority of the CWA. The upper high over the Gulf of Mexico continues to be a strong synoptic feature that will influence the wetter pattern through the week. As the high remains in place, the quasi-zonal flow will begin to shift southwestward due to the formation of an upper low to the west and a period of weak ridging should extend over the southeast CONUS. With moisture to the northern part of the high pressure, isentropic lift should remain ahead of an approaching cold front. Guidance from the GFS and ECWMF are not in total agreement with the end of the week synoptic patterns, and whether an area of low pressure forms over the Great Lakes region. This low and associated cold front should bring another round of rain to the area. However, FROPA could progress slowly as guidance suggests a stall of the front across the southeast. Continuing from Wednesday morning onward, likely PoPs for the western portion of the CWA with a downward trend in PoPs for the rest of the forecast period. Toward the end of the weekend, upper ridging begins to come back into the area on Saturday ahead of another possible cold front. Overall, expect a wetter pattern for next week and high temperatures well above normal, with Thursday being the warmest as temps creep up into the lower 70s in the southern and eastern portions of the Piedmont. A cool down for next weekend with the next FROPA on Thursday. Overnight temperatures will also remain well above normal. Continued cloud cover through the majority of the week will aid in insulating the area and lead to much warmer night temps until the weekend, when temps dip back to near normal.