textproduct: Newport/Morehead City

WHAT HAS CHANGED

Have issued a Heat Advisory for much of the CWA today.

The Small Craft Advisory for the Pamlico Sound and Northern Coastal Waters ended earlier this morning.

Updated Aviation Discussion.

KEY MESSAGES

1) Dangerous heat and humidity persists across ENC into this weekend.

2) There is a chance for some strong thunderstorms this weekend as instability builds across ENC.

3) Increasing chances for hot and humid conditions to return next weekend.

DISCUSSION

KEY MESSAGE 1...Another warm night across ENC with temps generally in the 70s and 80s this morning. A few isolated showers have been noted along the Hwy 264 corridor overnight associated with a weak mid level shortwave, but this activity is quickly pushing offshore so generally expect partly cloudy and dry conditions across ENC through daybreak.

Going to sound like a broken record, but once again it will be hot and humid today, and once again we have issued heat advisories across much of ENC starting at 11AM and going to 8PM. Similar setup today compared to yesterday with ridging around the area and SW'rly flow persisting keeping low level thicknesses generally at the same range as yesterday. This will lead to highs in the mid to upper 90s inland and into the low 90s along the OBX. Dewpoints once again get into the 60s to 70s today resulting in widespread heat indices between 100-110F. Will note with deeper mixing today, we may stay just below our typical criteria for areas in the heat advisory. However, all of ENC remains under the major heat risk category yet again and given the last several days of hot and humid conditions, and the lack of cooler nighttime temps this will compound the threat and the impacts will remain the same. Have issued the heat advisory for areas that saw criteria yesterday plus Lenoir County. Deeper mixing across our NW'rn counties (Greene, Pitt, and Martin) should keep heat indices low enough to preclude expansion of the heat advisory.

Low level thicknesses decrease several meters on Sat with temps a few degrees lower while dewpoints begin to creep back up resulting in another day with heat index values around 100-105 with the heat risk in the moderate to major range so could see one final day with heat advisories across ENC before we finally "cool" off. Realistically, this just means an end to heat indices around 105F finally.

KEY MESSAGE 2... We start to see the return of a more active pattern starting today as a shortwave tracks across ENC this evening with a stronger upper level trough/mid level shortwave and surface front approaching from the north and west Sat/Sun. This will act to progressively increase shower and thunderstorm chances each day with precip chances maximizing Sat evening through Sun morning. For today could see a few isolated showers and storms develop along the seabreeze and coming in from the west as the first shortwave moves across the region. With MLCAPES generally around 1000-2000 J/kg this afternoon but no shear across ENC, there is a low end threat for gusty winds (40-50 mph) in the strongest storms this afternoon and evening.

Prefrontal trough then sets up Sat afternoon with the aforementioned front approaching our northern zones Sat evening and pushing through the area Sun. Instability generally ranges from 1000-2000 J/kg of ML CAPE Sat and 750-1500 J/kg of ML CAPE Sun, and deep layer shear increases slightly to 25-30 kts. Combined with greater upper level support, thunderstorms could become more organized Sat afternoon and again on Sunday bringing a damaging wind threat (40-60 mph gusts) to much of ENC on Sat. SPC has also outlined ENC under a marginal risk (level 1 of 5) for severe weather on Saturday.

KEY MESSAGE 3... While we likely cool down at the beginning of next week under NE'rly flow, hot and humid conditions return to the area bringing yet another threat for an extended period of hot and humid conditions. NWS probabilistic heat risk guidance suggests much of the area has a 50% + chance at seeing major heat risk levels starting around Thurs/Fri next week and CPC has put ENC under a moderate risk for hazardous temperatures during this timeframe as well. Either way, make sure to pay attention to trends in the forecast to see if this threat persists or chances lower as we get closer to next weekend.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

Primarily VFR conditions are expected through the day today and tonight as weak surface ridging remains over the Mid-Atlantic. But of note, a couple of upper level waves plus gradually increasing moisture may support a slightly higher chance of SHRA and TSRA today, especially during the late afternoon and evening hours. Confidence in this activity is moderate, as there still appears to be some limiting factors for TSRA development. But, given recent trends in guidance felt confident enough to include a PROB30 group for TSRA at PGV/ISO where the greatest risk is to see TSRA between 22Z Fri and 02Z Sat to account for this threat as activity may come in from the west this evening bringing a low end threat for sub-VFR vis/ceilings as storms roll through the area. Things clear out tonight with mostly clear skies by late tonight.

Winds have eased up since last evening and will remain light but steady this morning before increasing once again this afternoon as the thermal gradient develops. Expect SW winds to gusts to around 20 kts this afternoon and evening before easing after sunset.

Outlook (Saturday through Tuesday): As we get into the weekend, an upper level trough and associated surface front approaches increasing chances for showers and storms as well as sub-VFR conditions to ENC. Could see improving conditions on Monday with mainly VFR conditions forecast Mon and Tue under clearing skies and light NE winds.

MARINE

Widespread 10-20 kt southwesterly winds are noted across our waters this morning. Have seen frequent gusts up around 25-30 kt as well along our coastal waters and Pamlico Sound with 5-7 ft seas noted along the coastal waters. This coincides with the ongoing Small Craft Advisories this morning. Lighter winds are noted across the other inland waters. Do expect winds to gradually ease this morning with SW'rly winds falling to 5-15 kts with gusts up to 20 kts across all waters. This will end the SCA's across the N'rn coastal waters and Pamlico Sound over the next few hours. However, across the coastal waters south of Oregon Inlet this reduction in winds will be brief with winds once again increasing to 15-20 kts with gusts up to 25-30 kts this afternoon and evening so the SCA will remain across these waters into Sat morning.

Outlook (Saturday through Tuesday): Once again not much change in the forecast as conditions gradually improve Saturday, then will see a backdoor cold front drop through the waters late Saturday night and Sunday with winds becoming NE around 10-20 kt with seas building to 3-5 ft. A weak area of low pressure may form along the stalled front to the south Monday keeping E-NEly flow across the waters through early next week.

MHX WATCHES/WARNINGS/ADVISORIES

NC...Heat Advisory from 11 AM this morning to 8 PM EDT this evening for NCZ045>047-080-081-090>092-094-193>196-198-199- 203>205. Beach Hazards Statement through this evening for NCZ195-196- 199-204-205. MARINE...Small Craft Advisory until 8 AM EDT Saturday for AMZ152-154- 156-158.