textproduct: Newport/Morehead City

WHAT HAS CHANGED

The chance of thunderstorms was decreased for much of the area for the remainder of the evening and overnight hours.

Heat Advisory issued south of Highway 264 for Saturday.

KEY MESSAGES

1) Hot and humid temps persist across ENC through the weekend into early next week.

2) Scattered shower and thunderstorm activity expected daily through the next few days as frontal boundary meanders over the region, bringing a marginal risk of severe storms and flooding.

3) Next front approaches early next week, bringing another round of shower and thunderstorm activity to ENC.

DISCUSSION

KEY MESSAGE 1...Latest surface analysis shows a stalled frontal boundary stretched NW to SE across southeast Virginia and the nearby coastal waters. Convection ongoing along this boundary has shown a weakening trend on radar and satellite recently, likely owing to a stabilizing boundary layer. There is still plenty of elevated instability, though, and given the enhanced convergence in the area, it stands to reason that convection may be able to survive to the coast of SE VA / NE NC, even if in a weakened state. Some guidance event hints at some additional development along the outflow of the ongoing convection. For now this seems less likely. Therefore, the chance of thunderstorms was lowered for the remainder of the evening and nighttime hours, with the highest probs focused across the NRN OBX.

Front will eventually sag southward across the region tomorrow, although how far south is uncertain. 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 105 both Saturday and Sunday. The frontal boundary will lift back across the mid-Atlantic on Monday, entrenching the entire FA again in potentially dangerous heat and humidity as highs climb back into the upper 90s.

Heat Advisories remain in effect areawide for the rest of this afternoon. A new set of Heat Advisories has been issued from Pitt and Beaufort counties southward towards the coast for Saturday. 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...Overall pattern based on observational trends appears favorable for convective development with a highly unstable environment expected this afternoon with MLCAPEs forecast to climb to 2000-3000 J/kg, ample moisture, and favorable upper-level support with a mid-level shortwave forecast to progress through WNW flow around the periphery of a sub-tropical ridge that has been sitting over the southeastern CONUS for days. All that is left, then, are sufficient lifting mechanisms. The remnant surface trough and always reliable sea and sound breezes are suitable candidates for this afternoon, followed by an MCV currently driving decaying showers and storms over WV and VA but likely to reinvigorate convective activity push towards NC this evening.

CAM guidance has been in poor agreement over today's convective threat for both the 00z and now 12z suites. The HRRR and 3km NAM have been rather pessimistic on afternoon coverage, likely owing to depicting CI from a far more overcast cloud bank than current satellite depicts. The WRF-ARW, however, shows far more activity developing along sea sound breezes as well as off the inland thermal trough. It was also one of the minority of hi-res guidance that depicted this morning's earlier convection over area waters and the Outer Banks. Because it seems to more accurately be capturing the higher and more widespread instability we're currently observing, the forecast leans heavily in its direction for at least isolated to scattered activity this afternoon focused closer to the water. More CAMs are bullish on activity from the aforementioned MCV approaching the region early evening and decaying through the overnight hours.

If any severe threat does develop, it will be in the evening hours associated with the approaching MCV-driven complex as shear increases marginally up to 20-25 kt, mainly focused across far NE NC and SE VA presenting a damaging wind threat. Outside of this, a wet microburst threat cannot be ruled out from stronger iso cells. Additionally, with slow storm motions an isolated flooding threat can also not be ruled out.

Shower and thunderstorm risk will likely persist through the weekend as frontal boundary sags south and meanders over the area. With convective evolution each day at least partially reliant on mesoscale factors from the day before, larger than normal changes in model guidance can be expected from run to run. 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 frontal boundary looks to approach early next week after a brief lull Sunday. Still plenty of 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.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

TSRA ongoing across SE Virginia have been on a weakening trend recently, but this activity may still survive to the coast of NC over the next few hours. Guidance suggests the greatest TSRA risk should remain east of the TAF sites. For this reason, PROB30s have been pulled from the TAFs for the remainder of the night. We'll continue to closely monitor trends, though, as some guidance suggests outflow from the ongoing TSRA may be enough to kick off some additional development later. Otherwise, VFR conditions are forecast to prevail through much, if not all, of the night.

On Saturday, a front draped across the area, plus building instability and increased moisture should be sufficient for a greater coverage of TSRA compared to today. 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+.

Outlook (Saturday night through Tuesday): More isolated TSRA activity is possible mainly Sun evening. Next more widespread threat is possible on Monday ahead of the next front.

MARINE

Latest observations show south to southwesterly winds at 5-10 kt across area waters, with winds closer to 10-15 kt in sounds and northern waters. Offshore, seas remain at 2-3 feet. Expect winds today to increase further with the thermal gradient, with a few isolated gusts to 25 kt not out of the question, mainly for soundside waters and coastal zones north of Hatteras. The front will also be a focal point for showers and thunderstorms, mainly focused across northern sounds and waters into the evening hours.

Outlook (Saturday through Tuesday): Front will gradually push south across area waters tomorrow and stall, bringing at least a brief period of northeasterly winds to portions of the water, highest probability north of Ocracoke. The front will likely meander through Sunday before lifting back northward and ushering back area-wide southwest winds of 10-20 kt. There is a low risk of SCA conditions on Monday into Tuesday with this feature. Each day will bring a low to moderate risk (20-40%) of showers and thunderstorms to area waters.

CLIMATE

Record High temps for 08/14 Friday

LOCATION TEMP/YEAR New Bern 97/2023 (KEWN ASOS) Cape Hatteras 91/2019 (KHSE ASOS) Greenville 99/1918 (COOP - Not KPGV AWOS) Morehead City 93/1995 (COOP - Not KMRH ASOS) Kinston 104/1925 (COOP - Not KISO AWOS) Jacksonville 96/2019 (NCA ASOS)

MHX WATCHES/WARNINGS/ADVISORIES

NC...Heat Advisory from 11 AM to 8 PM EDT Saturday for NCZ044-079- 080-090>092-094-193>196-198-199. MARINE...None.