Marine Weather Net

Cape Hatteras to Ocracoke Inlet, NC out 20 NM Marine Forecast


OVERNIGHT

W
WINDS
10 - 15
KNOTS

THU

SW
WINDS
15 - 25
KNOTS

THU NIGHT

NW
WINDS
20
KNOTS

FRI

NW
WINDS
20 - 25
KNOTS

The Marine Weather Forecast In Detail:
AMZ154 Forecast Issued: 1001 PM EDT Wed Apr 08 2020

SMALL CRAFT ADVISORY IN EFFECT FROM THURSDAY MORNING THROUGH LATE FRIDAY NIGHT
Overnight...W Winds 10 To 15 Kt, Becoming Sw Around 5 Kt Late. Seas 3 To 5 Ft. Dominant Period 6 Seconds. Isolated Showers And Tstms Late This Evening And Early Morning.
Thu...Sw Winds 15 To 25 Kt. Seas 4 To 6 Ft. Dominant Period 6 Seconds. A Chance Of Showers And Tstms.
Thu Night...Nw Winds Around 20 Kt. Seas 4 To 6 Ft. Dominant Period 7 Seconds.
Fri...Nw Winds 20 To 25 Kt With Gusts Up To 30 Kt. Seas 4 To 6 Ft. Dominant Period 6 Seconds.
Fri Night...Nw Winds 20 To 25 Kt With Gusts Up To 30 Kt, Diminishing To 15 To 20 Kt After Midnight. Seas 4 To 6 Ft.
Sat...Nw Winds 15 To 20 Kt, Diminishing To 5 To 10 Kt In The Afternoon. Seas 3 To 5 Ft, Subsiding To 2 To 3 Ft In The Afternoon.
Sat Night...S Winds 5 To 10 Kt. Seas 2 To 3 Ft.
Sun...S Winds 15 To 20 Kt, Increasing To 20 To 25 Kt. Seas 3 To 5 Ft, Building To 7 To 10 Ft. Showers Likely.
Mon...S Winds 25 To 30 Kt, Becoming W 20 To 25 Kt. Seas 9 To 12 Ft, Subsiding To 7 To 10 Ft. Showers Likely. Winds And Seas Higher In And Near Tstms.
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Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1000pm EDT Wednesday April 8 2020

Synopsis
A series of weak disturbances will move across the area into Thursday with a mainly dry cold front pushing through the area late Thursday. Cooler high pressure fills in late in the week before a stronger frontal system impacts the region Sunday into early next week.

.NEAR TERM /Overnight/... As of 10pm Wed...Line of bkn thunderstorms with rain continues to push sewrd through the FA. The convection has become sub severe, and only expecting some gusty winds and brief heavy rains, albeit still observing frequent lightning. Still have probability of precipitation decreasing markedly after around midnight when storms should be moving offshore.

Prev As of 630pm Wed...We are watching several clusters of strong to severe thunderstorms in the northern NC Piedmont, which are quickly charging sewrd towards the NC Coastal Plain, and will arrive in the next couple hours. If they hold together, they will present and damaging wind and large hail threat. Chc probability of precipitation for thunder still in good shape through midnight.

Prev discussion...As of 345pm Wed...Upper level analysis shows deep northwesterly flow aloft with a weak mid- level shortwave diving out of the Ohio Valley. At the surface, weak and broad high pressure was situated over the Bahamas with a cold front stalled near northern Virginia.

Earlier noted outflow boundary has thrown a wrench in the original forecast with dew points dropping into the low 50s inland, with resulting RAP analyzed CAPES struggling to reach 500 J/kg along southern portions of the CWA with even lower values north of Highway 264. This is despite nice warming into the low to mid 80s. 12Z CAM suite continues to advertise a band of showers and storms beginning to impact the region from north to south starting at 23Z, with the latest runs of the HRRR (High-Resolution Rapid Refresh) advertising that line being initiated by outflow from the current cluster of storms over the Central Appalachians. The near-storm environment will be characterized with CAPEs of 500-1000 J/kg and effective shear of 30-35 kt, coupled with straight hodographs, suggesting an isolated damaging wind threat or hail threat is possible. Storm Prediction Center has our northwest counties in a Slight Risk with a Marginal Risk elsewhere.

Convective activity is expected to clear the Crystal Coast by around midnight with partly cloudy skies and light winds in its wake, although with mild airmass still in place lows will only fall into the low to mid 60s. Low dewpoint depressions suggest a patchy fog threat although confidence is low.

Short Term - Thursday
As of 400pm Wednesday...CAMS depict another band of showers and thunderstorms crossing our area from west to east as part of a decaying MCS cross the Ohio and Tennessee valleys overnight. Weak pre-frontal convergence is expected with light south/southwesterly surface flow. CAMs suggest a ribbon of ~1000 J/kg are possible right around daybreak with dew points in the low 60s. This, along with effective shear again around 30-35 kt, points to an isolated strong storm with damaging winds and some hail. Band will quickly clear the area midday with strong west/northwesterly winds developing in its wake with sustained 15-20 kts for the coastal plain and gusts up to 30 kts with deep mixing. Model guidance points to dew points falling into the upper 40s for the coastal plain although in cases of robust mixing this can be generous. Given this, there is concern with increased fire risk tomorrow afternoon with RHs around 30% and temperatures still climbing into the 80s in downsloping flow. No headlines necessary yet but next shifts will need to analyze further.

Long Term - Thursday Night Through Sunday
As of 330am Wed...A few showers and thunderstorms are possible Thursday ahead of a cold front that will cross the area later in the day. Drier and cooler conditions are then on tap for Friday into Saturday. The next storm system will impact the area Sunday into Monday with high pressure returning thereafter.

Thursday night through Saturday...High pressure building into the area behind the front will keep dry conditions in place Friday and Saturday, with temps below normal both days. Efficient radiational cooling is expected Friday night, with lows dipping into the 30s, and the potential for frost away from the beaches Saturday morning.

Sunday through Monday...Longer range guidance continues to converge on the solution of a potent H5 shortwave lifting from the south central US across the Midwest Sunday, with the associated complex surface low crossing the Tennessee Valley and riding up the Appalachian Mountains through Monday. This will likely result in a warm front crossing the area Sunday, with strong warm air advection on the back of a 50+ kt LLJ Sunday night into Monday. Given this wind profile and the potential for instability to quickly build, severe weather is a concern Sunday into Monday, as are strong gradient winds, especially along the coast. Details of the severe threat will be refined in the coming days, but currently carrying the threat for thunderstorms Sunday through Monday in the official forecast.

Current expectation is that a cold front will move through Monday, with generally dry conditions behind it for Tuesday. However, upper level heigheights could continue to fall, and dry conditions are not a guarantee Monday night into Tuesday as broad lift could occur across the region. Regardless, much cooler temps are expected Tuesday through the middle of next week.

Marine
Short Term /Tonight and Thursday/... As of 415pm Wed...Southwest to westerly winds prevail over the waters at 10-15 kts with a few gusts to 20 kt with seas 3-5 feet, except 2 feet to the north. Winds are weaker than expected with the passing outflow boundary earlier this morning, and therefore dropped the existing SCA. Cold front will approach and cross the waters tomorrow around midday with southwest winds 15-20 kt in the morning veering northwesterly at 15-20 kt in the evening, with seas in the outer southern and central waters reaching 6 feet by sunset.

Long Term /Thursday night through Sunday/... As of 330am Wed...Winds shift abrupartly to breezy NW behind the cold front, then gradually wane into Friday as cooler high pressure builds in. A strong frontal system will impact the area beginning Sunday, bringing the potential stronger winds.

Seas subside gradually Thursday night into Saturday as the windswell fades. Seas increase quickly beginning later Sunday as the next strong frontal system begins to impact the area.

Tides / Coastal Flooding
As of 415pm Wed...A perigean spring tide will bring elevated tidal levels today through the end of the week. Minor inundation of very low lying areas is possible around the times of primarily the evening high tide cycles, especially near inlets and along the beaches south of Cape Lookout tonight, then across all of eastern NC into late week.

NOAA Newport/Morehead City NC Office - Watches - Warnings - Advisories
NC...Coastal Flood Advisory until midnight EDT tonight for NCZ195- 196-199.
MARINE...
Small Craft Advisory from 11am Thursday to 2am EDT Saturday for AMZ154-156. Small Craft Advisory from 2pm Thursday to 2am EDT Saturday for AMZ152. Small Craft Advisory from 11am Thursday to 8pm EDT Friday for AMZ158.