Marine Weather and Tide Forecast for Hampstead, NC

NEAR TERM /THROUGH FRIDAY/
500 mb high pressure centered just east of the Bahamas will retrograde its way to near the Florida East Coast by Friday afternoon. Rising mid and upper level heights across the Carolinas are indicative of a warming airmass and guidance is pointing at Friday's temperatures rising another 2-3 degrees versus today with mid 90s expected for most inland locations.
Given dewpoints expected to mix down only into the 74-77 range during the afternoon, forecast heat indices of 105 to 108 will require the issuance of a Heat Advisory running from 10 AM until 8 PM.

GFS and NAM forecast soundings show mid level humidity should drop further on Friday with the arrival of stronger ridging aloft. Models were too dry yesterday and again today even as dry air has started working in aloft, so I'm hesitant to drop PoPs below 20 percent as suggested by 12z HRRR. NBM hourly PoPs of 20 percent along the SC coast and 30-40 percent elsewhere may work out better given the recent history of shallow convection in this tropical airmass.

And lastly, another warm and very humid night is expected across the area with lows ranging from 75 inland to around 80 on the beaches.
Wilmington's forecast low in the upper 70s should be the 43rd consecutive night of low temps 70 degrees or warmer this summer.

SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/
The mid-upper anticyclone will be in the process of drifting westward through this period, keeping dangerous heat and humidity in the forecast (highs in the mid-upper 90s on Saturday) which will likely necessitate a Heat Advisory for heat indices in the 105-109F range (with some isolated 110F possible in the hottest spots).
Subsidence and dry air aloft will keep rain coverage in the isolated to widely scattered range during this period while a stalled front and shortwave energy passing through the Mid-Atlantic will likely result in considerably more precip coverage north of the forecast area. With surface high pressure drifting westward across Florida, expect southwesterly winds to continue, helping to keep the sea breeze nearer to the coast. Overnight lows in the mid-upper 70s are expected, which are 3-6F above normal.

LONG TERM /SUNDAY THROUGH THURSDAY/
As the mid-upper anticyclone drifts further westward into the Gulf, troughing will dig into the Atlantic. As this occurs, the mid-level flow will become increasingly northwesterly over the area, opening the door to convective complexes sliding into the region as shortwave energy slides down the east side of the ridge. Guidance appears to be honing in on Sunday evening/night and Monday afternoon/evening as periods to monitor for convection arriving from the northwest. Over Monday night into Tuesday, a recent trend in the guidance is for a stronger backdoor front sneaking further south/southwest than originally anticipated, leading to a stronger push of lower-dewpoint air that may be able to knock them below 70F for the first time in weeks on Tuesday and Wednesday. If this comes to fruition, which is somewhat hard to believe given the time of year, deep dry air and subsidence would also arrive, putting an effective lid on almost all convection on Wednesday. As mentioned above, although this is a trend amongst the global guidance, it is hard to believe that a ridge over the Gulf won't end up stronger than modeled and thereby limit the backdoor front's southward progress. Nevertheless, this will need to be monitored closely.

Conditions will remain hot and humid on Sunday and Monday as the ridge slowly drifts west with highs in the mid-upper 90s on Sunday and mid-90s on Monday. Greater cloud cover and precip should limit daytime highs on Tuesday, although the timing of this potential backdoor front passage will impact temps and dew points, leading to low confidence on Tuesday through Thursday at this juncture.

AVIATION /18Z THURSDAY THROUGH TUESDAY/
Clusters of showers and thunderstorms have developed along today's seabreeze front extending from Myrtle Beach into Wilmington. With a westerly component to the background synoptic winds the seabreeze front will not make much inland progress today, keeping the convective risk large for KMYR, KCRE, and KILM through 20-21z today. For the inland airports convective activity is more isolated and less intense, but brief reduction in visibility in showers is still possible through 23z before cooling evening temperatures causes storms to dissipate.

VFR conditions are expected overnight into Friday morning. Cumulus with cloud bases in the 1500-2500 ft AGL range are expected to develop after sunrise, perhaps forming brief MVFR ceilings between 13-16z. But the trend should be toward rising ceilings and fewer convective showers around tomorrow versus the more widespread activity we see today.

Extended Outlook... Isolated showers and thunderstorms may bring brief MVFR ceiling and visibility impacts Saturday through Sunday, mainly the afternoon and early evening hours. Coverage may increase Monday and Tuesday as a front reaches the Carolinas from the north.

MARINE
Through Friday...The flow between Bermuda High Pressure well offshore and a cold front sinking as far south as southern Virginia should help veer winds across the Carolinas a little more westerly late tonight into Friday morning. There's a roughly 6 hour period centered on 9 AM Friday where west-southwesterly winds are expected.
Just like today there's the expectation a good seabreeze will develop Friday afternoon turning nearshore winds more southerly with an increase in speed to 15-20 knots. Scattered showers and thunderstorms moving quickly northeastward are also expected, primarily during the morning and early afternoon hours.

Seas should continue to average 3 to locally 4 feet in height with a 6 second dominant wave period. A new 8 second southeast swell will also develop but with a much smaller amplitude than the wind waves.

Friday Night through Tuesday...
Bermuda high pressure will maintain steady southwesterly flow through the weekend until a backdoor front approaches from the north early next week. Depending on if this front drops through, a northeasterly wind surge may occur in its wake.
Otherwise, winds will weaken as the front draws near on Monday into Tuesday as the pressure gradient becomes weakly-defined.
Waves mainly in the 2-4 ft range are expected to subside slightly to 2-3 ft as winds relax over Sunday and Monday.
Depending on the outcome of the northeasterly wind surge, waves would increase again as winds pick up and have a longer fetch over the Atlantic on Tuesday. The wave spectrum will be dominated by southerly wind waves of 2-3 ft with a period of 5 sec and supplemented by 1-2 ft southeasterly swells with a period around 8 sec.

ILM WATCHES/WARNINGS/ADVISORIES
NC...Heat Advisory from 11 AM to 8 PM EDT Friday for NCZ087-096-099- 105>110.
Beach Hazards Statement until 8 PM EDT this evening for NCZ106- 108.
SC...Heat Advisory from 11 AM to 8 PM EDT Friday for SCZ017-023-024- 032-033-039-054>056-058-059.
Beach Hazards Statement until 8 PM EDT this evening for SCZ056.
MARINE...None.