textproduct: Newport/Morehead City

WHAT HAS CHANGED

Aviation section updated.

KEY MESSAGES

1) Dangerous, potentially record-breaking heat to impact the area through Friday

2) Strong cold front to bring relief from the heat this weekend into early next week, along with a risk of thunderstorms

DISCUSSION

KEY MESSAGE 1...An anomalously strong upper level ridge is forecast to spread east from the OH/TN Valleys into the Carolinas/Mid- Atlantic Region this week. Meanwhile, anomalous low-level thicknesses beneath the ridge, plus strong heating and persistent southerly flow, point towards the potential for unusually hot conditions for the area. In fact, some of our more reliable forecast aids point towards this being an outlier type of event from a climatology standpoint, with record highs possible.

The heat is forecast to peak Wednesday through Friday. However, there are some caveats worth pointing out. There is the potential for a weak front or convective outflow to dip south into our northern counties on Wednesday. Should this occur, a not-as-hot easterly onshore flow may hold highs down some around the Albemarle Sound and Northern OBX vicinity. One other potential caveat is thunderstorms. With subsidence aloft, the seabreeze should be muted this week. However, any convection that can develop upstream would have a tendency to propagate towards ENC thanks to the west/northwest flow aloft. Any convection that survives into the area could hold temps down some, especially with any afternoon convection. For now, these are not expected to be significant limiting factors, and even if so, it would most likely only impact a relatively smaller area of ENC.

In light of this, confidence is high regarding anomalous heat and humidity, with 2-3 days of significant heat impacts expected. In fact, the NWS' experimental heat risk guidance shows most of ENC in the "Major" to "Extreme" category for heat.

Regarding messaging, a Heat Advisory has been issued for most of ENC for Wednesday. For now, we have left out the central and northern OBX in light of the potential for a brief period of easterly flow to develop which would keep temps down some. Additional heat headlines are likely through the week. As was mentioned yesterday, it's less common for heat headlines to be issued in the month of September in our forecast area. The Heat Advisory for tomorrow is the first heat headline issued in September since 2020. Additionally, please see the "CLIMATE" section below for record information at select sites through Friday.

KEY MESSAGE 2...A strong cold front is forecast to encroach on the Carolinas late Friday, then push fully through ENC on Saturday. Ahead of the front, guidance is mixed on whether or not convection will manage to develop ahead of the front over, or upstream of, ENC Friday afternoon and evening. Upper level ridging may hold on one more day, but the signal in some guidance can't be ignored. In light of this, the forecast will show modest thunderstorm probabilities Friday afternoon and evening (30-50% chance). The synoptic setup appears fairly favorable for strong to severe thunderstorms on Friday if ridging doesn't limit deep convection. Most machine learning and probabilistic guidance favor this potential as well, and SPC has outlooked a portion of the area in a Slight Risk. The risk of convection continues on Saturday, but the evolution may hinge on Friday's convection.

Behind Saturday's front, highs are forecast to get bumped down to the 80s, with lows in the 60s. This will be a notable drop compared to the heat of the next few days. It may not end up quite as dry as some guidance previously forecast, but dewpoints in the 60s won't feel as oppressive as the next few days.

AVIATION /00Z WEDNESDAY THROUGH SUNDAY/

Forecast confidence is high over the next 24 hours.

Late tonight into early Wednesday morning, guidance shows less of a BR/MIFG signal compared to this morning. For this reason, VFR TAFs are favored over the next 24 hours. Of note, though, there is a weak signal for sub-VFR conditions for a few hours around KOAJ and KEWN.

NOTE: AMD NOT SKED has been appended to the EWN TAFs as the site is not transmitting through normal channels. The site is still reporting via telephone so it will be monitored, but not as frequently as when it is completely operational. The next closest ASOS is at Cherry Point (KNKT).

Outlook: Generally VFR conditions are expected to prevail through Friday morning. The risk of TSRA is then expected to increase Friday afternoon through Saturday afternoon as a cold front approaches from the north and interacts with a moist and unstable airmass. Prior to Friday, the risk of TSRA is expected to remain LOW. However, if any clusters of TSRA can develop to our NW, the steering flow would bring those towards ENC Wednesday and Thursday, and is something worth monitoring for planning.

MARINE

A typical summertime pattern is expected across area waters over the next couple of days, with a diurnal max in southwesterly winds of 10- 15kt each afternoon and evening. Seas of 2-4ft are expected during this time. Of note, long-period southeasterly swell emanating from the remnants of "Dolly" are expected to arrive this evening and last into Wednesday. Swell periods of 10-13s are expected during this time. The risk of thunderstorms is expected to remain low through Wednesday.

Outlook: Other than breezy southwest winds with the daily thermal gradient, generally good boating conditions are expected Thursday and Friday. Of note, though, wind gusts are likely to bump up against 20kt at times Thursday afternoon and evening.

Over the weekend, a cold front is forecast to move through on Saturday with an increased risk of thunderstorms followed by an eventually northerly wind shift. Northeasterly flow is then expected to last into early next week.

CLIMATE

Record High Temperatures for 09/02 (Wednesday)

LOCATION TEMP/YEAR New Bern 96/2014 (KEWN ASOS) Cape Hatteras 91/2018 (KHSE ASOS) Greenville 101/1932 (COOP - Not KPGV AWOS) Morehead City 91/1998 (COOP - Not KMRH ASOS) Kinston 103/1932 (COOP - Not KISO AWOS) Jacksonville 95/1998 (NCA ASOS)

Record High Temperatures for 09/03 (Thursday)

LOCATION TEMP/YEAR New Bern 95/2020 (KEWN ASOS) Cape Hatteras 91/2018 (KHSE ASOS) Greenville 101/1921 (COOP - Not KPGV AWOS) Morehead City 91/1998 (COOP - Not KMRH ASOS) Kinston 98/1993 (COOP - Not KISO AWOS) Jacksonville 96/2020 (NCA ASOS)

Record High Temperatures for 09/04 (Friday)

LOCATION TEMP/YEAR New Bern 98/1944 (KEWN ASOS) Cape Hatteras 92/2020 (KHSE ASOS) Greenville 98/1930 (COOP - Not KPGV AWOS) Morehead City 93/1959 (COOP - Not KMRH ASOS) Kinston 98/1980 (COOP - Not KISO AWOS) Jacksonville 96/2020 (NCA ASOS)

MHX WATCHES/WARNINGS/ADVISORIES

NC...Heat Advisory from 11 AM to 8 PM EDT Wednesday for NCZ029- 044>047-079>081-090>092-094-193>196-198-199. MARINE...None.