textproduct: Newport/Morehead City

WHAT HAS CHANGED

Lowered max t's by 5-10 degrees for the northern OBX through the next 4 days.

Lowered max t's by several degrees overall for ENC through the next 4 days.

Increased pops for shower/storm potential Wed night.

KEY MESSAGES

1) Risk of dangerous heat later this week.

2) Pattern expected to become more conducive for showers and storms late week into the weekend.

DISCUSSION

KEY MESSAGE 1...Guidance continues high with low level thicknesses later this week, with the warmest temperatures expected Thursday and especially Friday. While temperatures may flirt with records at best, forecast aids and ensemble guidance suggest multiple days of well above normal temperatures. This combined with increasing humidity is forecast to support widespread "feels like" temperatures of 100-105 degrees, with the best chance of reaching records and/or heat indices above 105 on Friday. Additionally, the NWS' experimental Heat Risk guidance shows a moderate to major heat risk for much of ENC from Friday into the weekend. The one caveat (discussed in more detail in KEY MESSAGE 2) is the potential for afternoon showers/storms late in the week as this could provide relief from the heat for some areas each day.

KEY MESSAGE 2...Increasing moisture and instability beneath weakening ridging aloft is expected to support a pattern that is more conducive to a daily risk of convection. Initially this may be mostly seen as a more active seabreeze. However, by the weekend there may be some added large-scale forcing from various upper level impulses forecast to move through, or glance, the region. While the strongest shear looks to be removed from the area, moderate to strong instability may support a daily risk of marginally severe, pulse convection (fairly typical for this time of year).

AVIATION /18Z MONDAY THROUGH SATURDAY/

Backdoor cold front moving through will lead to nerly to erly winds, with gusts approaching 20 kt this afternoon. A brief period of SCT low clouds may follow behind the front, esp interior areas. However, the risk of widespread bkn sub-VFR CIGs appears low.

Outlook (Tuesday through Saturday): High pressure builds into Tuesday with generally low-impact aviation conditions expected. Srly to swrly flow returns with inc moisture and instability within this flow slowly but surely. By Thu there will be small chances (20-30%) of afternoon showers/storms at any given location, esp inland areas along the seabreeze. These may bring brief gusty winds, and tempo reduction in vsby in heavier showers.

MARINE

A backdoor cold front has passed through with occasional gusts of 20-25kt through early evening. Waters favored in northeast flow (Pamlico Sound, mouth of the Neuse River) appear to have the highest chance to reach 25kt. It looks a bit marginal and brief with the wind gusts of aoa 25kt, so will hold off on SCA issuance attm. Seas of 4-5ft will be common, with some 6-7ft waves possible for the offshore waters with the flow against the Gulf Stream. Winds will diminish to 10-15 kt later tonight, and veer srly to swrly on Tue with speeds remaining in the 10-15 kt range.

Outlook (Tue night through Sat): High pressure continues to dominate. From mid to late week, a strengthening swrly flow is forecast to develop due to the strengthening thermal gradient. A daily risk of 25kt winds appears likely during this time, especially Wednesday and Thursday afternoon and evenings when the thermal gradient is expected to be the strongest.

MHX WATCHES/WARNINGS/ADVISORIES

NC...Beach Hazards Statement until 8 PM EDT this evening for NCZ203- 205. MARINE...None.