Key MESSAGE 1, The dog days of summer are upon us with several days of hot temps and humid conditions forecast for ENC. The key will be how widespread these conditions will be over the next few days. Latest surface analysis shows surface high noted across the Southeast with the previously mentioned stalled frontal boundary currently along the Hwy 64 corridor this morning with shower and thunderstorm activity riding from NW to SE along the northern periphery of this boundary across portions of eastern VA into our offshore waters. Much of this activity has remained rather weak and expect this to continue over the next several hours with much of the activity remaining offshore. Temps this morning remain around the 70s to near 80 with light and variable winds.
Aforementioned front will eventually sag southward across the region today, although how far south and how quick remains uncertain. The NAM being the slowest and furthest north solution barely getting the front south of the Hwy 70 corridor by this evening. While the HRRR and CMC push the front further south slightly faster getting south of the Crystal Coast by this afternoon. This will offer some relative relief over the weekend, but locations along and south of Highway 70 have the highest probability of seeing HI values at or exceeding 105F both today and Sunday. Will note coolest temps will likely be found along the NOBX where highs in the mid 80s are forecast today under steady NE flow. The frontal boundary will then lift back across the Mid-Atlantic on Sun/Mon as a warm front, entrenching the entire FA again in potentially dangerous heat and humidity as highs climb back into the upper 90s. While we look to have a cold front track across the region Mon night into Tue it wont cool the area much with temps remaining in the 90s into the end of next week and with dewpoints remaining in the mid to upper 70s as well, HI of 105F+ will be common across ENC to varying degrees each day.
Heat Advisories remain in effect starting at 11AM today and continuing into 8PM this evening. Depending on convective coverage this afternoon we may see an early cancellation of this heat advisory but that would be dependent on how much thunderstorm activity we get this afternoon. We continue to encourage anyone planning on spending time outdoors to stay hydrated and to limit exposure to the heat, if able.
KEY MESSAGE 2, As mentioned above, frontal boundary is currently noted along our far northern zones with shower and tstm activity riding along the northern periphery of this front. Forecast calls for this front to drop south today with some uncertainty with how fast and how far south this front gets before stalling over or just south of ENC. Much like yesterday, several boxes are checked to support at least scattered shower and thunderstorm activity with MLCAPES around 1500-2500 J/kg, PWAT's above 2", and a slight increase in deep layer shear especially around the front (closer to 25-30 kts). The one main difference compared to yesterday is we have the front around the area today, which should help to provide a focal point for thunderstorm activity across the region this afternoon and evening. Current forecast suggests a mainly dry morning with shower and thunderstorm chances increasing as the afternoon wears on as daily sea/river/sound breezes interact with the incoming front. Ended up keeping SChc to high end Chc PoPs in the forecast today given uncertainty with frontal placement and much like yesterday poor CAM agreement in coverage of thunderstorms today. Wrf NSSL and FV3 being the most aggressive while the NAM3K/HRRR being slightly drier. Any activity that does develop should gradually weaken and dissipate as the evening wears on. Then as we get into Sunday another round of shower and thunderstorm activity will be possible as this stalled front then lifts north as a warm front but once again uncertainty with precip coverage remains high. So the activity will certainly be very hit or miss today and tomorrow.
For both today and tomorrow the convective evolution will be heavily driven by mesoscale factors owing to the low confidence precip forecast and therefore thunderstorm forecast each day. Strongest storms could bring a damaging wind threat, frequent lightning, and torrential rainfall. The bottom line is the overall environment will remain at least marginally favorable for stronger storms and a flooding risk through the weekend, wherever activity manages to develop.
KEY MESSAGE 3, A second front is then forecast to track across the area on Mon into Tue with this front currently having a higher chance at sweeping across all of ENC and bringing a favorable environment for additional rounds of scattered shower and thunderstorm activity with a few of these storms potentially becoming strong to severe in nature. Still several details to hammer out, but medium- range AI NWP guidance points once again to at least a marginal risk of stronger storms for portions of the Carolinas, along with a heavy rainfall risk as humid airmass remains unyielding.
06z Saturday through Wednesday VFR conditions are noted across all of ENC this morning as the area generally remains south of an incoming weak frontal boundary. We do see scattered showers and thunderstorms across portions of our coastal waters but this activity should continue to remain east of the aviation sites for the most part this morning. As we get further into the day today, previously mentioned front will drop south today and become draped across the area. This plus building instability and increased moisture should be sufficient for a greater coverage of TSRA compared to Friday so have kept PROB30 groups in the forecast for this afternoon and evening across all TAF sites and adjacent areas. It's worth noting that this pattern is a low-confidence one, especially for TSRA and low CIG impacts, and amendments are likely. Of note, TSRA will be capable of LIFR VIS and gusty/erratic winds of 40kt+. Once we get into tonight expect any ongoing shower and thunderstorm activity to dissipate. Low end chance around the frontal boundary and to the north of it for some sub-VFR low stratus to develop tonight but confidence is low in this occuring so don't have more than a SCT deck of low clouds noted in the TAFs. Winds outside of any potential thunderstorm activity remain light through the period.
Outlook (Sunday through Wednesday): More isolated TSRA activity is possible, mainly Sun evening. So once we get to Sun, expecting primarily VFR conditions into Mon afternoon. Then as we get into Mon evening and Tue more widespread threat for sub- VFR conditions is possible on ahead of the next front before VFR conditions return Tue into Wed.
Latest obs show fairly widespread W-NW winds at 5-15 kts north of a stalled frontal boundary with 5-15 kt SW-W winds south of the front with 2-4 ft seas noted along our coastal waters this morning. The lone excpetion is across the waters south of Cape Hatteras to Cape Lookout where continued gusty winds (25+ kts) have remained this morning given the slightly pinched gradient and warm Gulf Stream waters allowing for sufficent mixing. As a result have issued a short fuse small craft advisory between Cape Hatteras and Lookout to account for this through 11AM. As the aformentioned front gradually pushes south, the pressure gradiaent should relax some allowing gusty winds to ease down to 5-15 kt across all waters with winds becoming NE-E north of the front and and remaining SW'rly south of the front today. As we get into tonight all waters see NE-E winds at 5-15 kts as front finally pushes south of our waters. Seas will generally remain around 2-4 ft through tonight as well. The front will also be a focal point for showers and thunderstorms, mainly focused across northern sounds and waters into the evening hours.
Outlook (Sunday through Wednesday): The front will then meander north Sunday into Monday and usher back area-wide southwest winds of 10-20 kt. There is a low risk of SCA conditions on Monday with this feature. A second cold front then quickly tracks across our waters Mon night into Tue once again shifting winds to a NE-E direction Tue into Wed but ending any potential SCA threat. Each day will bring a low to moderate risk (20-40%) of showers and thunderstorms to area waters.
Nc, heat advisory from 11 am this morning to 8 pm EDT this evening for ncz044-079-080-090>092-094-193>196-198-199. Marine, none.
