Marine Weather and Tide Forecast for Ocean Isle Beach, NC

UPDATE
It's been an active afternoon and evening for convection across the eastern Carolinas. Cold temperatures aloft (500 mb temps near -14C) and steep mid level lapse rates (6.5C/km) plus a significant proportion of computed CAPE above the -10C level all set the stage for hail. So far large hail reports from been received from Socastee, Bucksport, and Yauhannah. Reports of small hail have been much more widespread including across the Cape Fear area.

A modest shortwave is approaching the coast now and should take most of the convection offshore with it by 9 PM. In its wake, a weak and rather shallow cold front will settle south along the coast shifting surface winds to the northeast. Low level moisture coupled with wet ground and cooling temperatures will likely yield areas of fog and low clouds overnight, especially across eastern South Carolina where I've included areas of fog in the forecast.

NEAR TERM /THROUGH TONIGHT/
Expect a pretty active period the next 36 hours with deep moisture in place and a few boundaries in the area (stalled front, sea breeze, and differential heating). However, not confident in development of widespread rainfall at any one time. Mid-level lapse rates are marginal at best and varying amounts of cloud cover have limited SBCAPE to around 1000 J/kg(with a few higher pockets) this afternoon and similar values are expected for Thu. There was a little more dry air in the low levels this morning based on 12Z soundings from CHS/MHX than what guidance was anticipating which likely led to the slightly delayed start. Not expecting this to be much of an issue for Thu, but something to look for. Storms that do develop will be capable of producing good rainfall rates.
Precipitable water is AOA the 90th percentile pretty much through Thu. The freezing layer between 11k-12k ft will allow for a deep warm cloud layer as the low levels moisten up and LCLs lower. There will be some weak shortwave influence, although it's weak enough that by itself it may not be able to generate any convection but it will help maintain storms that do develop.

What has happened this afternoon, development of isolated storms along the boundaries with additional storms developing as outflow from the first round kicks off additional storms, is likely again on Thu. Although instead of the sea breeze being favored inland SC may be the more favored location. Coverage will continue to expand as new storms pop up on outflow into the evening hours (today and Thu)
before convection starts to weaken and dissipate in response to decreasing instability. It may be a case where the hourly POP is too high yet the POP across a longer time frame is too low. Rainfall amounts will be quite variable too given the convective nature of the activity. Temperatures will continue to run on the warm side of normal with highs ranging from mid 70s to lower 80s and lows in the upper 50s to lower 60s.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/
Very low amplitude mid level ridge making for light flow through the period. Similarly high pressure centered to our northeast also rather weak for some paltry weather map wind barbs. High dewpoint air will still be in place keeping nighttime lows rather warm. As far as forcing for precipitation the synoptic scale won't offer much at all and so both nights will tend to be rain-free. Forecast soundings are quite moist however and so Friday afternoon's sea breeze should bring storm coverage worth low end chance range POPs as it makes healthy progress inland due to the aforementioned light flow aloft.

LONG TERM /SATURDAY THROUGH WEDNESDAY/
Mid level trough cuts off over NYS on Saturday, its trailing trough helping to push a cold front through the Carolinas. Models are surprisingly meager in their QPF, which may adjusted in the future, and have kept the inherited high chance to low likely POPs at this time given that the front itself has a good amount of baroclinicity for later in April. To that end the airmass change will be quite noticeable by Sunday and Sunday night. The remainder of the period features high pressure overhead early Monday shifting offshore to a true warm season position thereafter.

AVIATION /00Z THURSDAY THROUGH MONDAY/
Convection continues to fire even as the sun sets across the eastern Carolinas as a subtle disturbance aloft approaches the coast. Thunderstorms have a high likelihood to affect the KILM airport through 01z. Elsewhere, isolated showers could drift near local airports through 03z, but the trend should be toward drier conditions as the upper level disturbance moves offshore.

A weak cold front will drift south along the coast later this evening, backing wind directions to the northeast. There is a moderate to high likelihood of IFR conditions in low clouds and fog developing between 04-08z across KCRE, KMYR, and KFLO airports, lasting through sunrise Thursday. There is a moderate potential for MVFR ceilings to affect KLBT and KILM overnight, but somewhat drier air expected to arrive from the NE may reduce fog potential at these two airports.

Conditions should gradually improve to VFR at all local airports between 13-16z Thursday, but there is a moderate potential for new convection to develop during the afternoon hours (mainly 19-23z) affecting the South Carolina airports.

Extended Outlook...There is a moderate potential for ground fog Friday morning and again Saturday morning. An approaching cold front Saturday could bring showers and thunderstorms with short-lived MVFR to IFR conditions. VFR should predominate early next week.

MARINE
Through Thursday...Ill-defined gradient will persist over the waters through Thu as Bermuda High remains the main feature.
Enhancement of onshore flow each afternoon and evening in response to the sea breeze is expected, but otherwise winds will generally be 10 kt or less with an easterly component. This will keep seas around 2 ft with the dominant wave being an easterly swell.

Thursday night through Monday... Not much of a gradient in place to start the period meaning light winds with some sense of directional variability before a southerly component comes to dominate even if only weakly. Wind waves then could fall below the 7-9 second E to SE swell in regards to power. SW flow picks up Saturday as cold front approaches, flow then turning to N and NE on Sunday steepening wave faces as period shorten. Considerable veering on Monday as the post- frontal high starts overhead but progresses offshore rather quickly.

ILM WATCHES/WARNINGS/ADVISORIES
NC...None.
SC...None.
MARINE...None.