textproduct: Newport/Morehead City

WHAT HAS CHANGED

Aviation Disco updated.

KEY MESSAGES

1) Dangerous heat today.

2) Pattern expected to become more conducive for showers and thunderstorms for the weekend into early next week. Couple of chances for severe thunderstorms this evening and tonight and again on Sunday.

DISCUSSION

KEY MESSAGE 1...SFC drifts further E with midlevel ridging centered to the S allows for thickness values to peak today, allowing MaxTs well into the upper 90s for most, a low triple digits away from the coast. This will threaten records (see climate section below for record high info). Tds continue to creep upwards today, low to mid 70s in the afternoon, AppTs/heat indices/"feels like" temps to reach 105-109degF across all mainland zones away from the coast. We have issued a heat advisory across these areas from 1100-2000edt. The NWS experimental Heat Risk guidance shows much of ENC in the major category, with a few areas nearing the extreme category which lends further confidence in impactful heat across ENC today. We will cool down slightly in the following days with highs in the low to mid 90s into early next week so while heat headlines are not anticipated, it will still feel like full swing summer, and any precautions you can take if you plan to be outside for longer durations are encouraged. While it's a lower end potential (less than 20%) the caveat to the current forecasted heat and heat indices through this weekend will be the coverage of convection (see KEY MESSAGE 2 for additional details), and the potential for high clouds/convective debris. Both of those factors can have significant impacts on the temperature forecast each day.

KEY MESSAGE 2...Synoptic pattern is expected to shift towards something more favorable for convection across ENC starting tonight with a weak front crossing the FA SAT and stalling to the S of the area into early next week when troughing aloft develops, opening moisture transport from the Gulf. However, this shouldn't be read as a high coverage of thunderstorms each day. Stronger showers and tstorms develop to our W and approach the area near sunset. This activity could hold on long enough, and potentially reinvigorate over the area when the prefrontal trough interacts with the seabreeze as it works over the Coastal Plain. While MLCAPE values may be on the downtrend Fri evening lowering to 1000 J/kg or less by about 9-11PM, ongoing activity could be more cold pool dominated and sustain itself as it enters into ENC. Greatest risk is generally north of Hwy 70 with wind (40-60 mph) being the primary hazard. SPC has also highlighted this area under a Slight Risk (lvl 2/5) given the attendant wind threat. The storms over this area could also bring periods of heavy downpours. Hourly NBM PoPs keep the area under 40-50% PoPs for the first half of the night with lower PoPs (20-40%) over the coast in the early morning hours SAT as momentum carries the weakening showers and storms offshore. By the time the storms reach areas near the coast, they are expected to be weakening and mostly cold pool dominated, but still pose a threat of bringing strong winds along the outflow boundaries, and as such, SPC has outlined the rest of the FA in a Marginal Risk (lvl 1/5).

Temps aloft "cool" slightly as heights aloft fall ahead of the front and the stout mid level ridge begins to weaken, and this may support at least a risk of higher coverage seabreeze convection on Sat, particularly along the Crystal Coast seabreeze where likely PoPs are mentioned. The ample moisture noted by PWATs rising to 2-2.5in, strong destabilization due to typical summer time heating and the height falls aloft poses a threat for the development of tstorms which could be strong to marginally severe. Greatest threat lies N of the FA closer to the jet aloft, but storms in the area could bring strong winds.

Early next week, higher than climo shower and storm chances are in the forecast with the greater moisture content through the column leading to PWATs in excess of 2". Additionally, deep layer shear of around 30-35kt with weak cyclogenesis along another front set to approach and stall over the area MON may support a modest increase in the potential for organized convection, some of which could be on the strong side. High pressure returns late next week when high pressure builds in behind a mid-week front.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

VFR flight cats are forecast through the bulk of the period. SW winds continue today with gust around 15-20 kt, especially after the sea breeze pushes through. Could see isolated seabreeze thunderstorms during the afternoon, but coverage not enough to mention in the TAF at the moment, less than 25% chance. A better chance for showers and thunderstorms after 00z Saturday with an MCS approaching from the NW. Storms will be strongest over NWern portions (PGV) and weakening as they approach the coast. These storms could bring reduced VIS and strong winds. Have introduced PROB30 groups for PGV, ISO, and EWN with the greatest chance for flight op impacts at PGV. After showers/storms roll through, light SWerly breeze and VFR CIGs and VIS ahead of an approaching cold front set to cross through the FA early SAT.

Outlook: Better chance for afternoon/evening showers/storms this weekend when a front crosses the region Sat, stalling to the S and into early next week, with tempo reductions in vsby and/or cigs accompanying the heavier showers (best chance SAT afternoon over SWern zones/OAJ) and at least a chance of MVFR CIGs directly along the front as it crosses the area early Sat. Another front approaches and stalls over the area MON leading to a wet period early next week with greater chances for subVFR flight cats until the front clears through mid-week.

MARINE

SW winds around 10-20 kt with gusts slight above 20kt. Thermal gradients will relax some in early morning, but are expected to tighten up again this afternoon with near record temps inland. Afternoon and evening SCAs have been issued again for PamSound and central coastal waters. Seas along the coastal waters generally remain around 2-4 ft through Friday with very weak 1ft swell out of the E at 8-9sec and the bulkier windwaves on top ~2-4ft at 5sec.

Outlook (Fri night through Tue): The risk of thunderstorms will increase Fri night into early next week, with best chances in the late afternoon to evening hours. A front will cross Sat and stall to the S. SWerly flow returns SUN with another chance for more SCAs ahead of a front set to approach and then stall over ENC on MON. This front will clear through by midweek with high pressure briefly returning thereafter.

CLIMATE

Record High temps for 06/12 (Friday)

LOCATION TEMP/YEAR New Bern 95/2016 (KEWN ASOS) Cape Hatteras 89/1922 (KHSE ASOS) Greenville 98/1914 (COOP - Not KPGV AWOS) Morehead City 92/1952 (COOP - Not KMRH ASOS) Kinston 95/1986 (COOP - Not KISO AWOS) Jacksonville 95/2016 (NCA ASOS)

MHX WATCHES/WARNINGS/ADVISORIES

NC...Heat Advisory from 11 AM this morning to 8 PM EDT this evening for NCZ029-044>047-079>081-090>092-094-193-194-198. Beach Hazards Statement through this evening for NCZ195-196- 199-204-205. MARINE...Small Craft Advisory from 4 PM this afternoon to 11 PM EDT this evening for AMZ135-152-154.