textproduct: Newport/Morehead City

WHAT HAS CHANGED

Extended the Small Craft Advisory until 10 am with 6 ft seas still being reported across the central waters

KEY MESSAGES

1) An unsettled pattern persists through at least Thursday with multiple opportunities for showers and thunderstorms.

DISCUSSION

KEY MESSAGE 1...The front has lifted north of the area stretching across Hampton Roads to the western Carolina piedmont. The front will remain quasi-stationary through the middle of the week. Guidance differs some on where the front will stall. Wherever it stalls, it should be the primary focus for convection through Wednesday. Away from the front, convection should mostly be seabreeze-driven.

Confidence in where the highest coverage of convection will be each day is lower because of the uncertainty regarding the placement of the front each day. The mean storm motion parallel to the front, plus moderate instability and 2" PWATs will continue to support a risk of intense rainfall rates and possible flooding. If the front stalls along the VA/NC border, then the greatest risk of flooding would be focused there as well. Stay tuned for updates on the potential placement of the front each day and where the greatest risk of convection and possible flooding will be.

On Thursday, the front is forecast to get shoved back south as a cold front as a shortwave moves off the Mid-Atlantic/New England Coast. This may offer at least one more day of unsettled weather, but perhaps with a focus across the southern half of ENC as opposed to the entire area.

A modest increase in mid-upper level westerly flow from through Wednesday should lead to a bump up in deep layer shear to 20- 30kt. This suggests an increase in the potential for storm organization each day during that time. This combined with moderate instability of 1000-2000j/kg MLCAPE may support a marginal severe thunderstorm risk each afternoon and evening. On Thursday, shear is forecast to increase as the above-mentioned cold front moves through and this may lead to a slightly improved risk of strong to severe thunderstorms. Analog, deterministic, and machine learning guidance all hint at this potential as well.

AVIATION /12Z MONDAY THROUGH FRIDAY/

Showers have become more isolated this morning with VFR conditions returning most terminals, however a few locations are reporting IFR/LIFR mainly across far SW rtes, including ISO. Expect VFR to return here between 13-14z with pred VFR conditions through mid day, but then showers and thunderstorms expected to redevelop this afternoon with an increase in instability, with the storms most concentrated along the sea breeze. Conditions improve early this evening with loss if heating but guidance redevelops a low stratus deck overnight with sub-VFR conditions possible.

Outlook (Tuesday through Friday): A front is forecast to stall just north of ENC through the middle of the week, with the greatest risk of TSRA focused along it. Thus a daily risk of seabreeze TSRA appears likely, along with an associated wind shift. Periods of sub-VFR conditions can be expected where SHRA and TSRA occur, as well as each night and early morning (due to SCT/BKN low stratus layers).

MARINE

A warm front has lifted north of ENC waters with south to southwest flow of 10-20kt prevailing in its wake. Despite the front being to the north of most waters, a risk of thunderstorms will continue thanks to a broad area of lift, deep moisture, and instability present.

Seas remain elevated thanks to the recent long-period northeasterly fetch from the northern into western Atlantic. Seas are beginning to lay down, but still getting reports up to 6 ft across the central waters this morning, so will extended the Small Craft Advisory through mid morning.

Outlook: For those with boating plans from through Wednesday, a more typical summertime regime is expected, with a daily building of southwesterly winds up to 15-20kt each afternoon and evening with the strengthening thermal gradient. Occasional gusts to 25kt are expected during this time. In general, the risk of thunderstorms looks to be a bit lower compared to the past couple of days, especially for the coastal and offshore waters. The one potential exception is the inland rivers and the Albemarle Sound vicinity where the risk of thunderstorms looks higher compared to the coastal waters, thanks to the seabreeze and the potential for a front to be nearby.

MHX WATCHES/WARNINGS/ADVISORIES

NC...Beach Hazards Statement through this evening for NCZ195-196- 199-203>205. MARINE...Small Craft Advisory until 10 AM EDT this morning for AMZ152- 154.