High pressure will remain overhead through Monday, then shift offshore Monday night. This will allow a weak coastal trough, or weak coastal low, to move north along the coast on Tuesday or Tuesday night. A strong cold front then moves through Wednesday night, followed by the return of high pressure through the end of the week.
Through tonight As of 215 AM Monday,
Key Messages
- Above to well above normal temperatures expected Tuesday
- Chance of showers and thunderstorms expected to increase late Tuesday into Tuesday night
A weak cold front will push south across ENC early this morning, then stall offshore to the south. Weak CAA behind this front should support highs topping out a touch cooler today compared to yesterday, but not drastically so.
By tonight, the stalled front is forecast to begin lifting back north towards the coast as a warm front as return flow develops in the wake of departing high pressure. Increasing low-level moisture within the developing return flow is forecast to support the potential for increasing low clouds from south to north. Sometimes guidance is too quick with low cloud development in these return flow regimes, and this will play an important role in how cold it gets tonight. If low clouds are slower to return, lows will likely be on the colder side of guidance, and vice-versa if clouds move in quicker. The most likely scenario is for lows to bottom out late in the evening through about midnight, then slowly rise during the overnight hours, especially along the coast. For coastal areas, especially the Crystal Coast north through Hatteras, a few showers may develop prior to sunrise Tuesday as the above-mentioned warm front approaches.
Tuesday through Tuesday night As of 215 AM Monday,
A notably strong upper low is forecast to translate east from the Upper Midwest to the Great Lakes on Tuesday. The developing deep southerly flow ahead of the low will help encourage a warm front to lift north through ENC Tuesday or Tuesday night. Additionally, this regime is a fairly favorable setup for the development of a weak coastal low along the advancing warm front. Both global and hi-res short term guidance show a solid signal for this development, which should lead to an area of enhanced low-level convergence along its track. The main difference in guidance is the timing of the warm front and coastal low (ie. Tuesday vs Tuesday evening). Timing aside, whenever the low moves through, it is forecast to overlap with increasing, and notable, low-mid level moisture (PWATs of 1- 1.25"), and weak instability (MUCAPE of 250-500j/kg). The combination of enhanced low-level convergence, weak instability, and notable moisture should support an increased risk of showers and a few thunderstorms associated with the passage of the warm front and coastal low. Where thunderstorms occur, the lack of stronger instability, plus weaker large-scale forcing, should limit any strong/severe risk.
Despite the potential for increased cloudcover on Tuesday, southerly flow and rising low-level thicknesses should support above to well above normal temperatures. Even the "coldest" available guidance shows highs at or above normal. Assuming some breaks in the Sun, highs should manage to reach the 70s for most areas away from the immediate coast. With southerly flow continuing into the night, above normal temperatures during the day will carry over into a very mild night, with lows expected to be a good 15-20 degrees above climo for late November.
Wednesday through Sunday As of 215 AM Monday,
Key Messages
- Well above normal temperatures on Wednesday
- Cold and dry conditions expected on Thanksgiving
A notably strong upper trough will translate east from the Great Lakes to New England mid-week. A cold front associated with this trough is forecast to cross ENC Wednesday night. Prior to the passage of the front, moderately strong southerly flow and warm low level thicknesses are expected to support one more day of above to well above climo temps. Probabilistic guidance shows a 90%, or greater, chance of exceeding 70 degrees for most of ENC. Based on the higher end of guidance, a few areas could potentially reach 80 degrees. Heating of a moist boundary layer should support a plume of modest instability with MUCAPE of 500+ j/kg likely in the warm sector. Despite decent instability for this time of year, the strongest forcing with this front is forecast to be focused north of ENC, with some guidance only showing a very low risk of even seeing showers, let alone thunderstorms, along the front. If any deep convection manages to develop, the shear/instability combo appears supportive of a marginal severe thunderstorm risk, and this is shown in some machine learning and ensemble guidance. However, for now, the expectation is that a lack of stronger forcing will limit the severe thunderstorm risk. Stay tuned in case this risk were to increase.
In the wake of the cold front, a much colder and drier airmass will overspread the Carolinas as we move into the Thanksgiving holiday. Thanksgiving travel may be impacted at times with breezy conditions and a chance of showers/thunderstorms Wednesday, but for now, Thanksgiving looks to be cold and dry across ENC. By Friday, some areas may struggle to get out of the 40s for highs. The coldest night is expected to be Friday night as lows fall into the 20s and 30s. By then, we will be past the ending of our local frost/freeze program, and cold weather headlines will not be needed.
Of note, breezy and very dry conditions, plus ongoing drought, may lead to elevated fire concerns over the Thanksgiving holiday, and those with outdoor fire plans are encouraged to be mindful of the conditions.
Late in the weekend, high pressure is forecast to shift offshore, with a warming and moistening return flow developing. This may lead to an increasing chance of rain late by Sunday or Monday.
12z Monday through Friday As of 630 AM Monday, A VFR day in store today with light easterly winds. Monday night is likely to be VFR with high and mid level clouds overhead. Along the coast, some low clouds may move in early Tuesday morning ahead of an approaching frontal system.
Outlook: Another frontal system will bring the next chances of sub-VFR conditions and rain for Tuesday and Wednesday. There is a 15-30% chance of thunderstorms Tuesday night. After cold front moves through late Wednesday, VFR conditions are expected to return as high pressure builds in.
As of 215 AM Monday,
Key Messages
- Increased risk of elevated winds and seas from Tuesday night through Friday
A weak cold front will move south through area waters early this morning, accompanied by north winds of 10-15kt. Northerly winds today will eventually become easterly by tonight, then southerly by Tuesday. Southerly winds are then expected to build Tuesday into Tuesday night as the pressure gradient tightens ahead of an approaching cold front. Within the developing southerly flow, a weak coastal low is forecast to lift north through the area Tuesday afternoon or evening. This low marks the likely beginning of a risk of 25kt winds, especially for the coastal waters south of Oregon Inlet. Most guidance shows 20-25kt winds developing with this low, but some of the stronger guidance suggests frequent gusts of 30-35kt will be possible. Regardless, marine headlines will likely be needed for a portion of the ENC waters for Tuesday evening into Tuesday night. Seas of 1-3ft this morning will eventually begin to build on Tuesday, reaching 3-5ft by Tuesday night.
Outlook: Moderately strong southerly winds are expected to last into Wednesday, with a continued risk of 25kt+ winds. A strong cold front moves through Wednesday night with winds flipping around to the NW. Periods of moderately strong northwesterly winds are then expected through Friday. Most waters are likely to reach 25kt, or higher, gusts during this time. High pressure then builds in late Friday through Saturday with winds laying down to 5-15kt. For planning, the best boating conditions are expected to be on Saturday thanks to lighter winds and lower seas.
Nc, none. Marine, none.
