Marine Weather and Tide Forecast for Coinjock, NC

KEY MESSAGES
1) Chance for showers and storms returns today and Monday as a slow- moving front moves in.

2) Persistent onshore flow and a potentially strengthening coastal low will create a wetter, cooler, and breezier forecast for most of the week.

3) Widespread minor to moderate tidal flooding (inundation of 1-2 feet AGL in vulnerable areas) is likely by the middle of the week due to strong northeast winds, with localized major tidal flooding possible.

DISCUSSION
As of 325 PM EDT Sunday..

KEY MESSAGE 1...Chance for showers and storms returns today and Monday as a slow-moving front moves in.

Latest wx analysis shows a slow moving cold front across the Ohio River Valley slowly approaching the area today and Monday. With the front approaching, there is a chance of showers/storms both days. This afternoon/evening, the best chance for scattered showers/storms will be in the north/northwest portions of the area. An isolated strong to severe storm with damaging wind gusts in the piedmont cannot be ruled out, as SPC maintains a Marginal Risk of severe weather across this area today. With the approaching front being rather weak and not having enough strength to cross the local area, storms will likely struggle to become strong from lack of forcing. Some shower activity could linger into the overnight hours.

Monday, the slow moving front will continue to push further south, potentially taking all day to reach the NC border, and then pushing back north overnight. This will create quite a gradient in temperatures for Monday. For those north of the front, generally Richmond and north, highs will top out in the upper 70s to lower 80s. South of the front, mid to upper 80s will once again make their presence known. Our far southern NC localities could even approach 90 degrees. If the front does change its timing at all, this will affect the temperature forecast. The front will once again bring another chance of showers and storms, with the best chance south of the front with the higher amounts of instability. Showers and storms may be able to develop in the southern half of the area Monday afternoon with the front and building back towards the northern half. SPC has maintained a Marginal Risk of severe weather west of I- 95, with the main threat being damaging wind gusts. WPC continues with a Marginal Risk of excessive flooding for areas generally west of I-95 as well.

KEY MESSAGE 2...Persistent onshore flow and a potentially strengthening coastal low will create a wetter, cooler, and breezier forecast for most of the week.

The forecast for the rest of the week will be highly dependent on the location and strength of a developing low pressure off the coast. With the large high pressure parked to our north, we will be entering a prolonged period of onshore flow. A Cold Air Damming wedge set up looks likely for us Tuesday into Wednesday, though it isn't quite as strong as what models were portraying the last few days. With the wedge, forecast highs vary greatly across the area with highs on Tuesday in the lower 70s (locally upper 60s) in the piedmont and MD Eastern Shore and lower to mid 80s across SE VA/NE NC. Wednesday's highs are cooler with temperatures in the lower 60s across the piedmont to mid 70s across SE VA/NE NC. Will note that the NAM, which typically is the most aggressive (but can have the right idea with wedge set ups) has highs in the mid 50s in the piedmont and lower 70s along the coast on Wednesday.

Along with the cooler temperatures, breezy winds and wet conditions are expected through the end of the week. Winds will begin to increase on Tuesday as well, with coastal areas seeing gusty conditions by the evening and potentially lasting all the way into at least Friday. Rain chances will persist each day next week, with WPC placing us in a Marginal Risk of Excessive Rainfall each day.
The previous Slight Risk on Tuesday has been removed. Guidance does keep trying to develop localized areas of significant rainfall totals off and on through the period, so keep in mind that some instances of flash flooding may be possible as those rain chances remain. Some guidance is even showing a secondary surface low developing off our coast later in the week, which would prolong the period of impactful weather even longer. Regardless, this coastal low will bring impactful weather to our area for an extended period of time. Model differences and timing limitations are still creating some uncertainty in the details, so please stay tuned to the latest forecast as we work out the details.

KEY MESSAGE 3...Widespread minor to moderate tidal flooding (inundation of 1-2 feet AGL in vulnerable areas) is likely by the middle of the week due to strong northeast winds, with localized major tidal flooding possible.

Strong northeast winds are expected from Tuesday night through at least Thursday, which will cause water levels to rise across much of the area (especially along the bay, tidal rivers, and Atlantic coast). No tidal flooding is expected through Tuesday. A significant rise in tidal anomalies is forecast on Wednesday. Minor tidal flooding is likely (locally moderate) as early as the Wednesday morning high tide cycle, with minor to moderate flooding forecast during the Wednesday evening high tide, with localized major flooding possible. This corresponds to inundation of 1-2 ft AGL in vulnerable areas (locally 2-3ft). Specifics will become more clear as we get closer. The highest water levels will likely occur along the south/west side of the Ches Bay, tidal York/James, and Atlantic coast. The minor to moderate tidal flooding potentially persists through several tide cycles as NE winds remain elevated.

AVIATION /19Z SUNDAY THROUGH FRIDAY/
As of 150 PM EDT Sunday...

VFR conditions are expected to prevail for the first half of the 18z/20 TAF period. FEW-SCT high CU clouds around 3-5k ft have begun developing across the area this afternoon. VFR CIGs will continue through a large portion of the night, but MVFR (or locally IFR) CIGs likely push in from the north around 08-11z Monday through the early morning, affecting all but NE NC terminals (ECG). There is a chance of SHRA/TSRA this evening, mostly across northern and western terminals; however, confidence is too low to include in TAFs. If a wetting rain is received, patchy ground fog is possible. S-SW winds around 5-10 kt will continue through this evening, decreasing to ~5 kt overnight, then becoming more NE Monday.

Outlook: A stronger cold front slowly crosses the region Monday into Tuesday bringing a more unsettled pattern with degraded flight conditions through at least mid-week. Coastal terminals may also have elevated northeasterly winds for an extended period.

MARINE
As of 325 PM EDT Sunday...

Key Messages:

- Mainly sub-SCA conditions are forecast through Monday, although a brief east to northeasterly surge is possible late Monday afternoon/early evening behind a cold front.

- SCA level winds are forecast beginning late Monday night into Tuesday.
Confidence in a period of gales with NE winds continues to increase from Tuesday night-Thursday, with the strongest winds likely occurring from Wednesday-Thursday. This will lead to significant to potentially dangerous marine conditions with 10-13+ ft seas.

High pressure is centered off the Southeast coast this aftn. The wind is generally S/SE 10-15kt, and locally S 15-20kt off the MD coast. Seas range from 3-4ft N to ~4ft S, with 1-2ft waves in the Ches. Bay and locally 2-3ft at the mouth of the Bay. The wind gradually becomes SW 10-15kt this evening and then shifts to N later tonight as an initial boundary drops S along the coast. Seas will mainly be 3-4ft with 1-2ft waves in the Ches. Bay.

Confidence remains high in a significant pattern change this week. A stronger cold front will initially cross at least the northern half of the marine area on Monday, potentially making it to the VA-NC border. Winds will become NE and could increase to near 20 kt with gusts to 25 kt by Monday evening (best chances N). The front then may stall for a bit Monday night into the first part of Tuesday before advancing south across the entire marine area Tuesday into early Tuesday evening. NE winds are progged to increase to 20-25 kt south/25-30 kt north by Tuesday evening as stronger CAA ensues. A few gale force gusts are possible north of Parramore Island as early as late Tue aftn. Conditions could briefly approach SCA criteria across the Ches. Bay late Monday aftn/early evening. However, the duration is short and wind probs are no quite high enough to support any flags at this time.

An impressive 1040mb high will build across eastern Canada by the middle of the week as low pressure deepens a couple hundred miles offshore of the VA/NC coast. This will help strengthen the CAA and tighten the pressure gradient over the local waters. The strongest winds are still expected to occur on Wednesday-Thursday as the strong high remains anchored over southern Quebec and the offshore low continues to gradually deepen. The global models are in better agreement with respect to timing, and confidence in frequent gale force gusts is now high with local wind probs showing a 70-100% chc of 34+ kt wind gusts from Wed aftn through a good part of Thu. While prevailing gusts are generally forecast to be in the 35-40 kt range, a ~6 hour period of sustained gales with 40-45 kt gusts is possible across the ocean and mouth of the Ches Bay during this time. This will lead to significant to potentially dangerous marine conditions from late Tuesday night through Thursday due to the strong winds and 10-13+ ft seas. It remains too early for Gale Watches, but expect these to eventually be issued for most of the marine area as the event gets closer. Solid SCA level winds will likely continue through the end of next week as the low potentially lingers offshore, with the wind trending to northerly later in the week and potentially NNW by later next weekend. Of course, the exact timing and placement of the synoptic scale systems are not locked in place yet, but models continue to come into better agreement regarding the general pattern. We will continue to monitor the trends as this gets closer in time.

There is a moderate rip current risk forecast for all beaches Monday from onshore flow. Dangerous surfing conditions are likely by the middle of the week with the prolonged onshore flow. Localized beach erosion is possible from mid to late next week as well depending on how things evolve.

AKQ WATCHES/WARNINGS/ADVISORIES
MD...None.
NC...None.
VA...None.
MARINE...None.