Key MESSAGE 1, Hot and humid conditions will continue through the weekend, peaking this afternoon and again Saturday. While elevated smoke from Canadian wildfires make continue to impact the area, available smoke guidance keeps the bulk of this north of the area through the weekend. Heat Advisory continues for most of the area through this evening. Conditions look very similar for Sat, with highs in the mid/upper 90s inland and upper 80s/low 90s for the beaches, combined with dewpoints 70-80 deg. Will likely need another Heat Advisory for most of the area Sat with heat index values likely in excess of 105 deg.
KEY MESSAGE 2, There are several factors expected to support an increasingly active pattern from the weekend into next week, but also with some important considerations.
Upper level troughing is forecast to develop across the Eastern U.S. With ridging shifting away from the area. The lack of subsidence, alone, can help support a more active pattern. Additionally, persistent southerly flow east of the trough, potentially with a subtropical connection, should act to enhance low-mid level moisture across the area. Meanwhile, heating of a moistening boundary layer should lead to sufficient instability and reduced inhibition in support of periods of convection. Today, iso showers and storms developing with the seabreeze this afternoon. This convection should wane with loss of heating and svr threat looks low at this time.
At the surface, the front draped through the Albemarle Sound this afternoon will lift back Nward into VA tonight, acting to "warm- sector" the entire FA for the weekend. Lee-side troughing and, eventually, a frontal boundary that will reach the FA by MON should provide areas of enhanced low- level forcing this weekend. Spc has portions of the FA outlined in a Marginal Risk (lvl 1/5) of severe thunderstorms SAT. This threat for day 2 mostly encompasses the potential for stronger storms that develop W and N of the FA in the afternoon reaching NWernmost zones after sunset SAT. Spc day 3 outlook for SUN features a Slight Risk (lvl 2/5) for a portion of the FA, and a Marginal Risk (lvl 1/5) for the remainder of the area. Moisture pooling and low level convergence will be maximized SUN afternoon into SUN night as the cold front approaches. Pwats peak on the order of 2 and 3/4in with increasing afternoon and evening instability through the weekend. Additionally, while guidance remains mixed, there is a modest signal for low pressure development across the northeastern Gulf. Whether this obtains tropical characteristics or not, it could act to enhance rainfall along the SE coast if it ends up getting pulled north ahead of the above-mentioned upper trough. Not all guidance show this though, as some ensemble members take the low west across the northern Gulf Coast. The National Hurricane Center has increased probs a bit to 30% probability of development over the next 7 days, and it is something we will be monitoring through the weekend and into next week.
Tropics aside, deterministic and machine learning guidance continue to show a good signal for some strong to marginally severe thunderstorm potential during this period of active weather. Right now the signal is the strongest on Sunday. Though this could be dependent on lingering convection Sat night and how much destabilization is possible Sun. Given increased forcing from the approaching front and the potential tap of subtropical moisture, heavy rain and some hydro impacts may eventually be realized.
18z Friday through Wednesday Predominant VFR flight cats are expected to prevail through the period. An iso shower/storm possible this afternoon, but too low prob to include in TAFs. Very shallow patchy fog possible again overnight, but again too low confidence and prob to include at this time.
Outlook (Saturday night through Wednesday): The risk of TSRA is expected to slowly increase Saturday night, becoming more likely from Sunday into early next week. Sub-VFR conditions can be expected along with the TSRA impacts.
Latest surface and buoy obs indicate SE-SW winds 5-10 kt with seas 1-2 ft. A cold front approaches from the north this afternoon, likely only making it to the Albemarle Sound region, before lifting back into VA tonight. This will lead to a slight wind shift over Nern waters where the winds becoming southeast or east for several hours. Eventually, Serly flow will return for all waters tonight behind the departing boundary. Winds increase to 5-15 kt later this afternoon and tonight with seas building to 2-3 ft. Moderate SSW winds will increase to 20-30 kt Saturday evening, peaking Sat night and early Sunday. Have issued SCAs for the nearshore coastal waters and the Pamlico Sound.
Outlook (Saturday night through Wednesday): Over the outer coastal waters, frequent gale-force gusts still look possible for several hours Saturday night into Sunday morning, but less likely. Seas will quickly respond to the winds, building to 4-7ft Saturday night. Elevated winds and seas are expected to last into early next week for the nearshore coastal waters. For the outer waters, elevated winds and seas may last for much of the week.
Nc, heat advisory until 8 pm EDT this evening for ncz029-044>047- 079>081-090>092-094-193>196-198-199-204-205. Marine, small craft advisory from 4 pm Saturday to noon EDT Sunday for amz135. Small craft advisory from 4 pm Saturday to 8 am EDT Sunday for amz150. Small craft advisory from 4 pm Saturday to 11 pm EDT Sunday for amz152-154-156-158.
