Oregon Inlet to Cape Hatteras, NC out 20 NM Marine Forecast
|Tonight...Sw Winds 20 To 25 Kt With Gusts Up To 30 Kt. Seas 4 To 6 Ft. Dominant Period 6 Seconds. Scattered Showers With Isolated Tstms After Midnight.|
|Mon...W Winds 15 To 20 Kt With Occasional Gusts Up To 25 Kt, Becoming Sw 10 To 15 Kt In The Afternoon. Seas 3 To 5 Ft. Dominant Period 6 Seconds. Isolated Showers And Tstms.|
|Mon Night...Sw Winds 10 To 15 Kt, Becoming Nw After Midnight. Seas 2 To 3 Ft. Dominant Period 5 Seconds. Scattered Showers With Isolated Tstms.|
|Tue...Nw Winds 5 To 10 Kt. Seas 2 To 3 Ft. Dominant Period 5 Seconds In The Morning. Isolated Showers In The Morning.|
|Tue Night...W Winds 5 To 10 Kt, Becoming Nw 10 To 15 Kt After Midnight. Seas 2 To 3 Ft.|
|Wed...N Winds 15 To 20 Kt. Seas 3 To 4 Ft.|
|Wed Night...N Winds 15 To 20 Kt With Gusts Up To 25 Kt. Seas 4 To 6 Ft.|
|Thu...Ne Winds 20 To 25 Kt. Seas 5 To 7 Ft. A Chance Of Showers.|
|Fri...E Winds Around 25 Kt, Becoming Se After Midnight. Seas 6 To 9 Ft, Building To 8 To 9 Ft. A Chance Of Showers In The Morning. Showers Likely. A Chance Of Tstms. Winds And Seas Higher In And Near Tstms.|
| Area Forecast Discussion|
National Weather Service Newport/Morehead City NC
330pm EDT Sunday September 25 2022
A cold front will move into eastern North Carolina tonight, but not fully move offshore until Monday night. High pressure then builds in mid-week. Late in the week, Tropical Cyclone Ian will interact with the stalled front offshore, leading to a more unsettled period.
Near Term - Through Tonight
As of 300pm Sunday...An upper level impulse, embedded within the broad ERN US upper trough, will cross the Mid-Atlantic States this evening, then move offshore by tonight. At the SFC, a cold front will sweep southeast out of the Ohio Valley, reaching central NC by this evening. The front will then begin to slow down as it moves into ENC, due to the better upper level support shifting NE away from our local area.
Moderate to strong low to mid level moisture transport will occur ahead of the advancing s/w, with PWATs (Precipitable Waters) climbing back to around 1.50". However, the 12z MHX sounding reveals several substantial dry layers, both in the low and mid-levels, with a PWAT (Precipitable Water) below 1", and it will take some time to moisten the column prior to the arrival of the s/w and cold front. At this time, it appears there will be sufficient moistening and lift to support scattered, to perhaps numerous, showers this evening along the advancing cold front. Despite strong deep layer shear, instability will be limited by warmer temps aloft and a lack of better quality moisture. For this reason, I capped the thunderstorms potential at slight chance through tonight. Of note, there may be a slightly better overlap of shear and instability across the central Outer Banks area this evening/tonight where a strong thunderstorm cannot be ruled out. In general, though, the best chance of thunderstorms should remain offshore through tonight.
Short Term - Monday
As of 100pm Sunday...Tonight's front will get hung up near, or just southeast of, the ENC coastline on Monday. The best low-level forcing and instability will be focused along the front, and is where the best chance of showers and thunderstorms will be during the day Monday. Model guidance is generally favoring the coastal waters for showers along the stalled front, but the front's close proximity to the southern coast probably still justifies keeping some low probability of precipitation in. The main change I made from the previous forecast was to limit the shower/storm risk to the immediate coastline, with a lowered risk inland.
Long Term - Monday Night Through Sunday
As of 330pm Sun...A secondary cold front will push through on Monday night as cool high pressure builds in from the west through mid week. The effects of Tropical Cyclone Ian could begin to be felt Thursday into next weekend as moisture from the cyclone interacts with a developing strong coastal trough into the weekend. The gradient between Ian to the south and west and strong high pressure to the north and east will produce an extended period of strong easterly to northeasterly winds leading to potential coastal flooding issues.
Monday Night...Cold front will approach and move through overnight and spawn scattered showers for eastern zones during the late night period. Any thunder should remain offshore as instability will be meager. Temps still mild, generally in the upper 50s interior to mid 60s coast.
Tuesday through Wednesday...High pressure builds in stronger from the west Tuesday and Wednesday, forcing the aforementioned front offshore and bringing a few days of cool and dry weather. N to NW flow prevails as deep troughing will be in place, with strong upper subsidence ensuring justifying a dry forecast. Temps trend cooler with moderate Cold Air Advection occurring...near normal on Tuesday then 5-10 degrees below climo Wed. Overnight lows will be correspondingly cool, esp Wednesday morning when clear and near calm winds allow for temps to drop to the mid 40s inland with 50s on the coast.
Thursday through Sunday...Strong inverted coastal troughing will develop mid to late week as Tropical Cyclone Ian is expected to move into the eastern Gulf of Mexico and Florida. Much of the forecast for late next week is then predicated on what Ian does, though there is good agreement that periods of heavy rain will impact ENC as inverted troughing acts as a PRE and moisture from the cyclone interacts with this feature. Thus have inc probability of precipitation to 50-70% Fri/Sat. Other significant impacts, including strong winds, tornadoes, and coastal hazards are possible as well late week into the weekend, but confidence in Ian's track is still too low for any precise details. Monitor updates from the National Hurricane Center for the latest track expectations for Ian.
SHORT TERM /through Monday/... As of 300pm Sunday...Southwesterly winds continue to increase this afternoon ahead of a cold front approaching from the northwest. Small Craft Advisories will kick in through the afternoon in tandem with the increasing winds. The winds will then gradually subside from west to east late tonight as the pressure gradient relaxes along the slowing, and weakening, frontal boundary. Seas have been slower to respond to the increasing winds, but should continue to build to 4-6 ft through late this evening, then begin to fallout by sunrise Monday, with seas of 2-4 ft common during the day. The current marine headlines nicely cover the wind and sea hazards, and no changes were needed compared to the previous forecast.
Along the above-mentioned front, scattered showers and thunderstorms will be possible this evening through Monday, some of which could produce wind gusts in excess of 34kt.
LONG TERM /Monday night through Friday/... As of 345am Sun...The gradient continues to weaken through the day Monday as a boundary stalls near the coast, then pushes offshore Tuesday and Wednesday with high pressure building in from the west bringing mainly light to moderate winds with seas lingering around 2-4 ft. A developing coastal trough will tighten the gradient beginning later Wednesday and Wednesday night, with a period of hazardous marine conditions possible as TC Ian could interact with the trough and bring prolonged strong winds and hazardous seas.
Tides / Coastal Flooding
As of 330pm Sun...An extended period of strong east to northeast winds will impact ENC later in the week as strong high pressure to the northeast and Tropical Cyclone Ian to the southwest strengthen the pressure gradient. This may lead to strong rip currents, high surf, coastal flooding and beach erosion.
NOAA Newport/Morehead City NC Office - Watches - Warnings - Advisories
Small Craft Advisory until midnight EDT tonight for AMZ131-137- 230. Small Craft Advisory until 6am EDT Monday for AMZ135(Pamlico Sound)-150-152- 154. Small Craft Advisory until 6am EDT Monday for AMZ156-158. Small Craft Advisory until 2am EDT Monday for AMZ231.