textproduct: Newport/Morehead City

WHAT HAS CHANGED

Issued a Wind Advisory for the Outer Banks and Downeast Carteret County this evening (wind forecast increased)

Increased temperatures ahead of this afternoon's cold front

Marine...Northern rivers and sounds were upgraded to a Gale Warning for the post-frontal winds this afternoon

KEY MESSAGES

1) A strong cold front will cross the area this afternoon/evening with gusty winds, widespread rain, and a few thunderstorms expected. Thunderstorms may be capable of producing damaging wind gusts and an isolated tornado. Low probability (10-20%) of a wintry mix behind the front (generally north of Highway 264).

2) Temperatures rebound this weekend ahead of a strong cold front early next week

Marine...Conditions will deteriorate through the day with Gales expected this afternoon through late tonight.

DISCUSSION

KEY MESSAGE 1...As a potent upper level shortwave moves east through the Mid-Atlantic today, a strong cold front will track across ENC and bring gusty winds, widespread rain, and a few thunderstorms. Given that the FROPA is expected to reach the area ahead of peak heating, instability will be slightly muted. However, temperatures have trended warmer ahead of the front, so instability has followed suit. The latest HREF is showing ensemble mean SBCAPE of 500-750 J/kg along the front with a worst case scenario (ensemble max) of 1000-1250 J/kg. 300-400+ m2/s2 of 0-3 km SRH and well above 50 kt of deep layer shear will create an environment capable of producing bowing thunderstorms with damaging wind gusts in excess of 50 mph. Hodographs don't appear favorable for tornadogenesis, but given the amount of shear and helicity at play, a few rotating updrafts will be possible. The most likely scenario is widespread gusty showers with a few embedded thunderstorms this afternoon and evening.

Temperatures will fall so rapidly behind this front (approx 10 degrees/hour) that some models are showing a brief changeover to a wintry mix of rain, snow, and sleet this afternoon/evening (generally north of Highway 264). Chances of this happening are higher near the NC/VA border, but latest HREF probs for wintry precip types have increased. No accumulations or impacts are expected given that 1) cold air will be chasing the moisture and 2) it was in the 80s yesterday.

KEY MESSAGE 2...Our highs in the post-frontal airmass will still be warmer than average, but we'll feel a notable drop in temperatures. Friday will reach the low 60s and we'll rebound to the mid 60s (coast) to mid 70s (inland) on Sunday and Monday. A deep upper level trough will dig across the CONUS late this weekend and reach the East Coast by early next week. At the surface, a strong cold front will cross the area late Monday/early Tuesday. This system will bring increased shower and thunderstorm chances Sunday through Monday night. A significantly cooler airmass will build in behind this front with highs on Tuesday and Wednesday forecast to be in the 40s and 50s.

AVIATION /12Z THURSDAY THROUGH MONDAY/

Pred VFR conditions at the TAF sites through the morning hours with breezy S-SW winds. However, patchy sea fog will sub-VFR conditions to terminals along the Crystal Coast early this morning. LLWS will also be a concern through 12-13Z with a strong low level jet in place.

A strong cold front will push through ENC this afternoon bringing a threat for strong to severe thunderstorms along the front. Latest guidance showing the threat for storms between 17-19Z across western rtes and 19-21Z across eastern rtes. Damaging wind gusts will be the primary concern with the thunderstorms along with sub-VFR conditions. The front will also bring a northerly wind shift with a significant surge with gusts to around 30-40 kt and potentially a brief period of even higher gusts. The post frontal winds will bring a cross wind component to EWN runway 4R/22L. MVFR cigs expected to persist for several hours behind the front with lingering showers. Conditions improve fairly quickly this evening as high pressure builds into the region bringing a much drier airmass. Winds are also expected to quickly diminish this evening.

Outlook...Pred VFR conditions expected Friday through Saturday. The next frontal system is expected to impact ENC Sunday through Monday bringing periods of sub-VFR conditions in showers and thunderstorms.

MARINE

Increasingly hazardous marine conditions are expected today due to a strong cold front that will cross the area this afternoon/evening.

Southwest winds at 20-25 kt with gusts to 20-30 kt will continue through this morning. This afternoon, the winds will swiftly veer to the north-northwest and surge to 30-40 kt with gusts to 35-50 kt late this afternoon/early this evening. Gusts in excess of 45 kt are expected over a brief period of time this evening and will be most likely across the Gulf Stream waters. Winds will quickly improve behind the front with gusts forecast to drop below 25 kt by late tonight. Seas will peak this afternoon/evening at 5-8 ft.

Gale Warnings are in effect for all coastal waters, the Pamlico Sound, and the northern rivers and sounds. Small Craft Advisories are in effect for the inland rivers but a few Gale force gusts are still possible, especially near the mouths of the rivers.

The cold front will be accompanied by a risk of thunderstorms, the strongest of which may produce enhanced wind gusts and brief waterspouts.

Outlook: Winds and seas will lay down Friday and Saturday with more benign marine conditions expected. Winds and seas will rebuild Sunday into Monday associated with the next strong cold front.

MHX WATCHES/WARNINGS/ADVISORIES

NC...Wind Advisory from 4 PM this afternoon to 10 PM EDT this evening for NCZ196-203>205. MARINE...Gale Warning from 3 PM this afternoon to 8 PM EDT this evening for AMZ131-230-231. Gale Warning from 3 PM this afternoon to 11 PM EDT this evening for AMZ135-152-154-156-158. Small Craft Advisory from 1 PM this afternoon to 11 PM EDT this evening for AMZ136-137. Gale Warning from 3 PM this afternoon to 10 PM EDT this evening for AMZ150.