General summertime troughing is expected to remain in place through early next.
Today As of 215 AM Friday,
Key Messages
- Thunderstorm risk expected to be focused along the coast through this evening
An upper level wave/remnant MCV will shift offshore early this morning, leaving behind a light westerly low-level flow across the eastern Carolinas. While not strong, this flow should lead to drier air aloft, and lower PWATs for much of ENC today. The one exception is along the coast, where PWATs will be the highest. Heating of a residually moist boundary layer should allow MLCAPE of 1000-1500 j/kg to develop today. While notable, it's not expected to be as high as the past couple of days. Deep layer shear will continue to be weak, which when combined with the lower instability, should keep the risk of severe thunderstorms low. Ensemble and machine learning guidance suggest a lowered severe risk as well.
In light of the above, the expectation for today is for convection to be more scattered in nature compared to yesterday, and mainly confined to the seabreeze. With the westerly low- level flow in place, the seabreeze should get pinned closer to the coast, and is why the risk of thunderstorms should mostly be focused in that area. The one caveat today is the potential for a weak backdoor cold front to try to dip south along the NRN OBX/Albemarle Sound area. Should this occur, it would lead to a locally enhanced area of convergence in that area, with a locally higher risk of thunderstorms. This area was hit hard with heavy rainfall yesterday, and we'll have to closely monitor this area for a flooding risk. Ensemble guidance suggests rainfall amounts as high as 2-4" will be possible in that area (if the enhanced convergence is realized). A small Flood Watch may be needed if confidence were to increase regarding the heavy rain potential there.
Tonight As of 215 AM Friday,
Continued low-mid level drying plus upper level ridging building in should lead to a much lower risk of thunderstorms tonight compared to the past couple of nights. Light winds and wet soils may allow a fog risk to develop, but at this time, widespread impactful fog is not anticipated.
Saturday through Thursday As of 3 AM Fri, We remain in a summer like pattern through the long term period with daily chances for showers and thunderstorms. Upper level trough in the High Plains on Sat will gradually push E'wards into the Northeast by early next week. While upper level ridging off the coast of the Southeast retrogrades westwards into the Deep South with the approach of an upper level low. As we get into mid to late next week, another upper trough pushes across the Great Lakes and into the Northeast while upper ridging becomes entrenched across the Deep South, and the previously mentioned upper low becomes stationary near the Bahamas. At the mid levels, we will have multiple weak mid level shortwaves track across the Carolinas on Sat and Sun with a stronger mid level shortwave then pushing into the area on Mon into Tue eventually stalling across the Eastern Seaboard through about midweek.
We will see a chance for diurnal showers and thunderstorms on Sat and Sun. Pwats generally remain around 1.5-2.0 inches through the weekend, and this will be relatively low compared to previous days as some dry air associated with an approaching backdoor cold front infiltrates the area. This dry air will also likely limit shower and thunderstorm coverage this weekend with any sea/lake/sound breezes being the primary driver of convective activity given the lack of significant forcing. One caveat to this, is that we could see some enhanced convergence along a weak backdoor front on Sat which could bring higher than currently forecast shower and thunderstorm chances on Sat before the boundary dissipates. Moisture then pools and PWATs surge to greater than 2 inches across the area early next week as the previously mentioned incoming shortwave early next week pulls moisture northwards from the Gulf. This will result in a better chance at more widespread shower and thunderstorm activity as better forcing overspreads ENC. With PWATS remaining elevated and having ample deep layer moisture in place, any thunderstorm that develops over the next few days will bring a threat for heavy to excessive rainfall. Combined with the already wet ground from previous days activity, there will at least be a low end threat for some isolated flash flooding. As a result, WPC has placed the area in a marginal risk for excessive rainfall this weekend. While there will be a lack of wind shear across ENC over the next several days, 1000-3000 J/kg of MLCAPE is forecast to be in place each day bringing the potential for sub-severe wind gusts within the strongest storms.
High temps each day range from the upper 80s to low 90s with the hottest temps over the weekend. While we are not expected to reach heat advisory criteria this weekend, with heat indices around 100-105 F on Sat and Sun, any prolonged outdoor exposure could become hazardous to more vulnerable groups. Lows through the entire long term remain in the mid 70s.
06z Friday through Tuesday Through 06z Saturday As of 215 AM Friday,
Key Messages
- IFR/MVFR potential through early Friday morning
- TSRA coverage expected to be more scattered on Friday
SHRA and TSRA will continue to move offshore overnight, with a lowered risk expected through Friday morning. In the wake of the TSRA, guidance continues to advertise a strong signal for the development of low CIGs (IFR/MVFR). The TAFs will continue to reflect this expectation, but it should be noted that there is some uncertainty regarding the timing of the lowest CIGs. Stay tuned for updates.
By Friday afternoon, another round of TSRA is likely, but this time around it's expected to be more scattered in nature, and mainly confined to the coast. Since the strongest signal is along the coast, I hit the TSRA potential the hardest at KOAJ and KEWN, and removed the mention from KISO and KPGV. A lower TSRA risk is expected Friday evening (compared to the past couple of evenings). Drier low-level air building in may lead to a lowered risk of sub VFR CIGs Friday evening as well, but at the same time, may allow more of a patchy fog risk to develop.
Saturday through Tuesday As of 3 AM Fri, Several mid level shortwaves will track across ENC through early next week. This will continue to bring a daily threat for showers and thunderstorms as well as sub-VFR conditions. Reduced vis and ceilings from this activity is possible. Though will note, best chances to see shower and thunderstorm activity will be on Mon/Tue as the strongest in a set of mid level shortwaves pushes through the area and moisture pools out ahead of it. If it does rain then there will also be a fog and low stratus threat each night as well for areas that see meaningful rainfall.
Through tonight As of 3 AM Fri, Outside of any shower and thunderstorm activity across our coastal waters this morning, SW'rly winds remain around 10-15 kts with gusts up to 20 kts while seas across our coastal waters remain around 2-5 ft. Winds will change little during the daytime as slightly cooler temps today will allow for a weaker thermal trough inland resulting in the pressure gradient remaining more relaxed and keeping winds at about 5-15 kts across all waters while seas persist at 2-4 ft offshore. A weak backdoor cold front will track S'wards across just about half of our waters overnight shifting winds to a NE to E direction behind it. Current forecast shows this front stalling around an E-W oriented line near Cape Hatteras with winds across all waters easing to 5-10 kts tonight. There will be a chance to see additional shower and thunderstorm activity across our waters later today and tonight, bringing at least a low end threat for locally enhanced winds and seas within any thunderstorm that impacts the waters.
Saturday through Tuesday As of 3 AM Fri, With little change in the surface pattern through this weekend and early next week, expect rather benign boating conditions across our waters through the period. Winds become SW'rly across all waters at 5-10 kts by Sun as aforementioned back door cold front dissipates. Winds change little into Tuesday. Seas persist around 2-4 ft with daily chances for showers and thunderstorms continuing as well.
Nc, none. Marine, none.
