Marine Weather and Tide Forecast for Columbia, NC

NEAR TERM /UNTIL 6 AM MONDAY MORNING/
As of 730 PM...Heavy rain chances are ramping up north of 264, and also west of hwy 17, as front to our north sags south while at the same time a weak trough is bringing widespread heavy thunderstorms into our coastal plain counties over the next 1-3 hours. Still seeing potential for 3-6" of rain north of hwy 264 through the evening into tonight, although it is dependent on how far south the front actually drops.

As of 3 PM Sunday...

Key Messages

- Thunderstorms with a risk of flooding, strong winds, and an isolated tornado through this evening.

- Flood Watch remains in effect generally along and north of Hwy 264 through tonight.

A mid-level shortwave is analyzed on H2O vapor satellite imagery over WNC and E TN and KY. At the surface, a stalled sfc backdoor front resides across nern NC and will join forces with the incoming shortwave to initiate thunderstorms across the region late afternoon through the evening.

As opposed to the last several days, where afternoon convection was tied to the diurnal cycle due to lack of upper support, the incoming dynamics with aforementioned short wave will actually increase activity as we approach and move through the evening.

Heating of a very moist boundary layer is leading to moderate destabilization, with MLCAPE vals approaching 2K J/KG, with little to no inhibition. Given the moist, unstable, and uncapped airmass, isolated to scattered convection should initially develop along the developing sea/river/sound/bay breezes. The expectation is that this activity will then expand in coverage, intensity, and organization as the above-mentioned shortwave moves through with a modest increase in large-scale forcing and deep layer shear this evening.

The biggest threat with storms through this evening is heavy rain and areas of flooding, and 3-6" of rain is still forecast for northern parts of ENC in vcnty of the frontal boundary.
Localized higher amounts of over 6" is possible, per latest several runs of HRRR LPPM. It should be noted that if the boundary remains or drifts just north of ENC, the higher risk of flooding would be focused to the north of the Albemarle Sound.

Later tonight, any showers and storms will tend to diminish in intensity and coverage as they drift south of Hwy 264, and flood risk should diminish through the late night hours. Scattered thunderstorms with localized areas of heavy rain and gusty winds may still be a threat through dawn as they move through southern portions of ENC, as instability will still remain moderately high even through the late night hours.

SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/
As of 3 PM Sun...Aforementioned stalled front will still be draped across ENC to start your work week. Another round of thunderstorms appears likely for the afternoon hours. Depending on how quickly debris clouds from the overnight convection exits, destabilization could be greater or lower. More sunshine means a higher risk for severe storms, greatest threat localized wet microbursts, while clouds lingering through the day would mean less instability and storms not as strong. Attm retained likely pops due to the front and shortwave still in vicinity.

LONG TERM /MONDAY NIGHT THROUGH SUNDAY/
As of 330AM Sun...

Key Messages:

- Unsettled weather pattern into Tuesday with a chance for strong thunderstorms and heavy rain on Monday

- Potential for dangerous heat indices midweek into the end of next week.

Tuesday...Some minor tweaks to the forecast for Tuesday, but overall the general pattern remains the same as upper ridging will remain off the Southeast Coast while a weak and slow moving upper trough tracks across the Southeast Mon/Tue. Further to the west, a stronger but neutrally tilted upper trough will quickly progress across the Pacific Northwest and enter into the Plains Tues night and this will be our next potential weather- maker. At the mid levels, several weak but notable shortwaves will be transiting the base of the upper trough across the Mid- Atlantic and Southeast which will promote widespread lift across the area. At the surface, stalled front will gradually lift N'wards Mon night into Tue. By Tue we return to more diurnally driven showers/tstms associated with the Seabreeze circulation and mid level shortwave transiting the region.

Wednesday through next weekend...Previously mentioned upper trough will be the main feature of note into the end of the week with this neutrally tilted trough pushing E'wards into the Mid-Atlantic and Northeast by Fri. Currently GFS is the deepest and slowest with this trough with the Canadian and ECWMF guidance slightly quicker and weaker with the trough. Either way, at the surface we return to a more summer like pattern with thunderstorms primarily focused along the Seabreeze on Wed/Thurs with an incoming surface cold front from the west becoming the focus for potential shower/tstm activity on Fri. High pressure ridging then builds into the area over the weekend once again drying the area out. Of bigger note will be the hot and muggy conditions expected around midweek as a combination of temps in the 90s Wed/Thurs and dewpoints in the 70s will result in hazardous heat indices with "feels like" temps closer to the 100-110 F range each day. Will have to monitor trends, but the years first heat advisories may be needed next week if the current forecast holds. Once cold front pushes through on Friday temps will decrease slightly and the excessive heat threat will lower this weekend.

AVIATION /00Z MONDAY THROUGH FRIDAY/
SHORT TERM /through Monday/...
As of 730 PM Sunday...Thunderstorms will be moving through the northern, and northwestern part of the CWA (PGV to FFA) through this evening into tonight. Further south, coverage will be isolated to scattered as best since forcing decreases and air becomes a bit more stable behind an advancing sea breeze. TEMPO groups for TSRA with reduced vis and cigs are included in the 00Z TAF issuance for PGV and ISO, with the expectation being EWN and OAJ will be largely spared from the most robust convection.
Thunderstorms will be capable of very heavy rain and localized gusty winds. The TSRA risk is expected to gradually decrease towards daybreak, although low cigs (IFR/MVFR) will fill in behind the wave in the early morning hours. Monday, another round of thunderstorms are in the forecast, capable of heavy rain and localized strong wind gusts.

LONG TERM /Monday night through Thursday/...
As of 330AM Sun...Unsettled weather will continue to persist across the area into midweek as a stalled front will bring a threat for several rounds of showers and thunderstorms to Eastern North Carolina Mon. A more summer like pattern returns with diurnal thunderstorm activity developing along the Seabreeze on Tue/Wed. Either way this will bring a daily threat for sub-VFR conditions each day. In addition to this, early morning fog development will remain possible for areas that see rain.

MARINE
SHORT TERM /through Mon/...
As of 3 PM Sun...A weak area of low pressure is forecast to move east across northeastern NC and the nearby coastal waters later tonight, supporting an increased risk of thunderstorms.
Where thunderstorms develop, there will be the potential for 30-50kt wind gusts and waterspouts. The greatest thunderstorm risk through tonight looks to be focused across the inland rivers and sounds as well as the coastal waters north of Cape Hatteras.

A tightened pressure gradient south of the above-mentioned surface low should support another round of elevated winds and seas. Outside of thunderstorms, southwesterly winds of 15-25kt are expected, strongest across the Pamlico Sound. Additionally, seas of 3-4 ft are expected. These conditions will be close to Small Craft Advisory criteria, but confidence is low enough to hold off for now.

LONG TERM /Monday though Thursday/...
As of 330AM Sun...A stalled frontal boundary will bisect our waters from west to east, generally from around Lenoir county east across the Pamlico Sound, and just north of Hatteras Island into our coastal waters. This stalled front will bring a threat for several rounds of showers and thunderstorms Mon into Tue across all our waters with locally enhanced winds and seas noted within the strongest activity. In addition to this, light NE-E winds at 5-10 kts will be noted along the N side of this front on Mon (so Albemarle to northern half of the Pamlico Sound and along the coastal waters north of Cape Hatteras with 10-15 kt SW'rly winds noted south of the front Mon morning. Front will gradually lift N'wards through Tue allowing for the entire area to see SW'rly winds at 10-15 kts with gusts up near 20 kts. By Wed as high pressure settles into the region and thermal troughing sets up the gradient will pinch slightly allowing SW'rly winds Tue night into Wed to increase to 15-20 kts with occasional gusts up near 25 kts at times into Thurs. Seas will generally remain around 2-5 ft through the period keeping us SCA free through at least midweek.

HYDROLOGY
As of 3 PM Sunday...

Scattered to numerous thunderstorms are expected to develop in a moderately unstable, and anomalously moist, airmass later today through tonight. The airmass will be supportive of rainfall rates of 0.50"-0.75"/hr, with totals of 0.50"-2" where thunderstorms develop. These rates and amounts may support a few instances of flooding/flash flooding, especially in urban and flood prone areas. However, a locally higher risk of flooding and flash flooding may develop across parts of the area, depending on where a slow-moving frontal boundary stalls. Along this boundary, ensemble guidance suggests rainfall amounts as high as 3-5", with max rainfall amounts of 4-8"+ if training thunderstorms develop. Guidance differs on where the greatest risk will be focused, but there is enough of a signal to go ahead and issue a Flood Watch for a portion of ENC for this afternoon through tonight. The watch area highlights where the heaviest rainfall rates (1"/hr+) will be possible, as well as where flash flood guidance is lowest, and where soils are the most susceptible to excessive runoff.

Monday will bring the next threat for heavy rain which will be highly dependent on where the aforementioned front stalls.
Either way, with similar conditions to Sun in place across the area widespread 1-2" of rain with locally higher amounts will be possible on Monday and with already saturated soils from previous days rainfall in place, there will once again be a chance for flash flooding across parts of the CWA and a flood watch may become necessary in the coming day or so for portions of the CWA on Mon as well.

MHX WATCHES/WARNINGS/ADVISORIES
NC...Flood Watch until 2 AM EDT Monday for NCZ029-044>047-079>081- 091-203.
Beach Hazards Statement until 8 PM EDT this evening for NCZ195- 196.
MARINE...None.