Marine Weather Net

Surf City to Cape Fear, NC out 20 NM Marine Forecast


THIS AFTERNOON

W
WINDS
15 - 20
KNOTS

TONIGHT

W
WINDS
15 - 20
KNOTS

TUE

NW
WINDS
5 - 10
KNOTS

TUE NIGHT

W
WINDS
15 - 20
KNOTS

The Marine Weather Forecast In Detail:
AMZ250 Forecast Issued: 1148 AM EST Mon Jan 18 2021

SMALL CRAFT ADVISORY IN EFFECT UNTIL 10 PM EST THIS EVENING
This Afternoon...W Winds 15 To 20 Kt With Gusts Up To 25 Kt. Seas 3 To 5 Ft.
Tonight...W Winds 15 To 20 Kt With Gusts Up To 25 Kt, Becoming Nw 10 To 15 Kt After Midnight. Seas 3 To 5 Ft, Subsiding To 2 To 3 Ft After Midnight.
Tue...Nw Winds 5 To 10 Kt, Becoming Sw 10 To 15 Kt In The Afternoon. Seas 2 Ft.
Tue Night...W Winds 15 To 20 Kt With Gusts Up To 25 Kt. Seas 3 To 4 Ft.
Wed...W Winds 15 To 20 Kt, Becoming Nw 10 To 15 Kt In The Afternoon. Seas 3 To 4 Ft.
Wed Night...Nw Winds 5 To 10 Kt. Gusts Up To 20 Kt In The Evening. Seas 2 To 3 Ft.
Thu...Sw Winds 10 To 15 Kt, Becoming W 15 To 20 Kt. Seas 2 To 3 Ft, Building To 3 To 5 Ft. A Chance Of Showers.
Fri...Nw Winds 10 To 15 Kt. Seas 2 To 3 Ft. A Chance Of Showers Through The Day.
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Area Forecast Discussion
National Weather Service Wilmington NC
1212pm EST Monday Jan 18 2021

Synopsis
Seasonable temperatures, dry and occasionally breezy conditions will continue into mid week as a series of cold fronts cross the coast. A warming trend will follow as high pressure over the Southeast US moves offshore. Rain chances increase late this week as a series of weak low pressure systems pass approach the Carolinas.

Have included scattered stratocu/cu cloudiness for this aftn, with the bkn/ovc decks remaining north of the ILM CWA. This seen with latest visible sat imagery and shown by various model rh time height and sounding displays across locations within the FA. Overall, a sunny to mostly sunny sky. Have tweaked max temps a degree or 2 lower based on cold air advection, winds and potential partial cloud deck.

SCA (Small Craft Advisory) was re-raised for ILM SC AMZ254 due to active wind gusts to 25 kt given the configuration of this coastal waters zone and the wind direction.

Near Term - Through Tuesday
A cold upper level trough will move across the Carolinas today with 500 mb temps getting as chilly as -28C around noon. 850 mb temps should bottom out in the -3 to -4C range. There won't be enough moisture even with 6000+ feet of vertical mixing to generate clouds, so expect full sunshine with highs 52-56. Yesterday's verification numbers show GFS MOS continues to have a large warm bias, so I'm leaning toward the cooler ECMWF (European Centre for Medium-Range Weather Forecasts) and NBM for highs.

High pressure will move eastward along the Gulf Coast today, reaching north Florida tonight. A light westerly wind will disrupt otherwise ideal radiational cooling conditions across the Carolinas and our lows should reach the lower 30s inland with some mid 30s on the coast. The surface ridge axis should move across the area and offshore Tuesday afternoon with light west winds backing southwesterly while sunshine continues. This should bring some marine influence along the coast where cooler air will advect onshore. Away from the coast, Tuesday's highs should warm into the upper 50s.

Short Term - Tuesday Night Through Wednesday Night
High pressure moves offshore on Tuesday as a weak cold front approaches the area on Tuesday night. No precipitation is expected with the front (at the moment) due to a dry air mass in the lower levels and a lack of forcing overall. Temperatures overnight remain in the upper 30s or lower 40s due to a combination of mid and high-level clouds and light winds. Weak cold advection and downslope winds will cancel each other out on Wednesday as highs approach upper 50s to near 60. High pressure continues to sit just to our SW overnight with lows in the mid 30s.

Long Term - Thursday Through Sunday
Clouds and rain chances increase on Thursday as moisture spreads eastward. A set of weak disturbances will ride along a stationary front late Thursday and Friday as showers increase in coverage from west to east, especially Friday. As high pressure begins to build southward on Friday, models hint at the stationary front pushing southward as a cold front. This would limit rain chances late Friday as drier air builds over the Carolinas. Have maintained a chance of rain as the ECMWF is a little slower and further north Friday night into Saturday morning. High pressure is likely to start influencing our weather on Saturday as clear skies return through Sunday. Upper flow begins to ridge and best cold air advection remains well north, so afternoon highs are likely to only be a degree or two below climo on Saturday and Sunday. High pressure remains in control on Monday before the next storm system develops over the central US.

Marine
Through Tuesday... 1023 mb high pressure will move eastward along the Gulf Coast today while 980 mb low pressure moves across eastern Canada. Moderate westerly winds will continue across our coastal waters today with gusts near 25 knots at times. 00z model blends are slightly stronger than GFS/NAM marine MOS guidance, but even going with the stronger blended winds shows conditions falling short of Small Craft Advisory criteria across South Carolina. It's a little closer across the Cape Fear coastal waters where I'm about 50 percent confident we'll reach advisory criteria late this afternoon or this evening. I've trimmed back the SCA (Small Craft Advisory) just to focus on the Cape Fear area beginning at 1 pm. As the high reaches north Florida after midnight our wind speeds should diminish to less than 15 knots and remain there through Tuesday. There's no significant swells in our corner of the Atlantic leaving short-period wind chop as the dominant wave through Tuesday.

Tuesday Night through Friday... Southwest flow continues Tuesday night at 15-20 knots ahead of a weak cold front. Behind the front, high pressure will build into the area, increasing the gradient and leading to a brief period with wind gusts near 25 knots and possible SCA (Small Craft Advisory) conditions; seas 3-5 feet. Winds veer, becoming NW on Wednesday, recovering from near-SCA (Small Craft Advisory) conditions. A weak disturbance will ride a stationary front late Thursday and Friday bringing an increase in rain chances. Gradient will increase yet again as SW flow increases to near 20 knots late Thursday. This will bring another potential period of hazardous conditions through Friday morning. Front may push southward on Friday as northerly winds develop and gradient weakens throughout the day.

NOAA Wilmington NC Office: Watches - Warnings - Advisories
SC...None. NC...None.
MARINE...
Small Craft Advisory until 10pm EST this evening for AMZ250- 252-254.