Marine Weather and Tide Forecast for Claremont, NC

KEY MESSAGES
1. Patchy fog and low stratus will gradually clear out late this morning into early afternoon. Otherwise, dry and much warmer today through Sunday.
2. Well below normal temperatures for afternoon highs and possible wintry weather for the northern mountains and adjacent foothills into the I-40 corridor Monday into Monday night thanks to the development of Cold Air Damming.
3. Temperatures will rebound following the Cold Air Damming erosion starting next Wednesday with well above-normal temperatures sticking around through the end of the upcoming workweek. Rain chances remain in the forecast but confidence is relatively low.

DISCUSSION
Key message 1: Patchy fog and low stratus will gradually clear out late this morning into early afternoon. Otherwise, dry and much warmer today through Sunday.

Weak in situ cold air damming will completely erode this morning, as sfc high pressure pulls off the East Coast. A southern stream upper trough with lots of dry air aloft will cross the area today. So once the CAD erodes, skies should clear out and result in pleasant, sunny conditions by mid-aftn.

With clearing skies expected across much of the area by early afternoon, temperatures are forecast to be around 10 degrees above normal. Thicknesses remain warm with added westerly/northwesterly downslope flow to bring highs around 15 degrees above normal Sunday, especially in the mountain valleys, foothills and Piedmont.

Key message 2: Well below normal temperatures for afternoon highs and possible wintry weather for the northern mountains and adjacent foothills into the I-40 corridor Monday into Monday night thanks to the development of Cold Air Damming.

A sprawling continental surface high (~1040mb) will shift across the Great Lakes Sunday night and set up shop over the northeastern CONUS by Monday behind a cold front the completes a full fropa across the CWFA late Sunday. In response, the synoptic set up supports the development of a Classical Cold Air Damming regime at the onset. At the same time, the southern stream jet will stretch from the Rockies through the Central Plains, and into the OH River Valley as multiple shortwaves reside within the mean flow. The leading wave is expected to arrive Monday morning and provide the first instance of precipitation across the region, especially over the North Carolina zones. Low-level WAA atop the cold dome will help to lock in the stable layer on Monday and allow for temperatures to make a drastic drop of 20-25 degrees compared to Sunday. Guidance are in better agreement with the strength of the CAD and would support thermal profiles cold enough for a light wintry mix, mainly in the form of freezing rain to develop over the typical colder spots during CAD in the northern mountains and adjacent foothills, with slightly higher confidence as the latest LREF guidance increased freezing rain probabilities to 35-55% for >0.01" and more guidance coming into slightly better agreement. Some of the deterministic guidance try to eek out a brief period of freezing rain over portions of the I-40 corridor late Monday, but confidence in that is much lower for this scenario. The surface high will be very transient as it shifts offshore the Northeast Coast into the northwestern Atlantic Monday night into Tuesday, allowing for more of an in-situ setup to take place Monday night into Tuesday. Guidance has sent the next shortwave a bit further north in the latest runs and has trended slightly drier for Tuesday, but moist upglide should be sufficient enough to produce some precip, but the colder air won't be as strong as the transition to an in-situ regime takes over, so all precip should be liquid. However, the area remains socked into CAD on Tuesday leading to temperatures remaining 5-10 degrees below normal for afternoon highs.

Key message 3: Temperatures will rebound following the Cold Air Damming erosion starting next Wednesday with well above-normal temperatures sticking around through the end of the upcoming workweek. Rain chances remain in the forecast but confidence is relatively low.

As the surface high continues to push further offshore over the northwestern Atlantic, the source for continued Cold Air Damming will be cut off and likely becomes more of a residual cold pool Tuesday night into the first half of Wednesday as the flow turns more out of the south-southwest. Anomalously high thicknesses will be present as anything left of a residual cold pool will quickly be eroded by low-level WAA, leading to much warmer temperatures by Wednesday. Wednesday is still iffy just based on how long it takes for the low cloud deck to scatter out during the day, but temperatures are expected to jump 15-20 degrees higher compared to Tuesday in the current forecast. Upper ridging offshore the Southeast Coast will keep the area well above normal through the end of the workweek with continued southwesterly moisture advection from the Gulf of America. As a result, daily PoPs remain in the forecast, but likely in the form of WAA showers, especially with coverage likely holding onto a diurnal trend. Wednesday remains mostly dry as that will be the transition day from the CAD setup into the WAA regime as it becomes fully established by Thursday and Friday.

AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
At KCLT and elsewhere: LIFR to MVFR stratus across the mountain valleys and entire Piedmont to start the 12z TAFs. The cloud layer is fairly thin, so as NW winds and mixing increase, the clouds should gradually erode around midday to early aftn, mainly from NW to SE, leaving mostly clear skies for the rest of the period. Confidence on the timing of cigs clearing to VFR remains high, given good agreement in the guidance. Winds will remain light, starting out NE, then becoming rather VRB by midday and continuing thru tonight. Good radiational cooling conditions tonight may support at least patchy fog development by daybreak Sunday, but only a minority of available guidance shows fog at any of the TAF sites. Will continue to keep fog mention out of the 12z TAFs.

Outlook: Cannot entirely rule out redevelopment of fog at least in rural locations late tonight into Sunday morning. Otherwise, VFR thru Sunday. A strong cold air damming setup is expected Monday into Tuesday, which may bring showers and associated restrictions Monday into Tuesday. VFR conditions likely return Wednesday.

GSP WATCHES/WARNINGS/ADVISORIES
GA...None.
NC...None.
SC...None.