High pressure will shift out to sea this morning. This will allow a coastal trough to develop offshore and move inland during the day today. A warm front then lifts north through the area tonight. A cold front will sweep east across the area Wednesday night, followed by a sprawling area of high pressure building in over the Thanksgiving holiday.
Through tonight As of 130 AM Tuesday,
Key Messages
- Above normal temperatures expected through Wednesday
Satellite imagery this morning reveals the development of a coastal trough south of the Crystal Coast. Radar imagery shows a few light showers associated with this feature, but nothing looks all that impressive at the moment. Short-term guidance continues to insist that isolated showers will be possible for several hours this morning as the trough moves closer to the coast. Eventually the trough is forecast to weaken, which should lead to a temporary lull in shower activity.
Later today and, especially, this evening into tonight, a developing warm front will lift north along the coast of the Carolinas as a fast-moving upper level shortwave glances the area. The combination of the glancing wave, increased convergence along the warm front, modest WAA, and increased moisture advection should support a quick round of scattered showers from this evening into tonight. The greatest chance of showers looks to be focused along the coast where low-level convergence is maximized. Weak instability developing may support a few thunderstorms tonight as well, although the lack of stronger lift and instability should limit any severe thunderstorm risk.
Despite a chilly start to the day, highs should quickly rebound today as southerly flow ensues. Strengthening southerly flow and continued WAA will lead to above normal temperatures continuing through tonight.
Wednesday through Wednesday night As of 130 AM Tuesday,
ENC will be warm-sectored for much of the day Wednesday, with southerly flow and building low-level thicknesses supporting above to well above normal temperatures. A tightening pressure gradient plus shallow mixing into the lower reaches of a strong SW LLJ should lead to breezy conditions for much of the area. Along the immediate coast from Cape Lookout to Cape Hatteras, occasional gusts of 35-40+ mph appears plausible.
Despite increasing low-level moisture and building instability, it still appears that the strongest forcing will be focused off to the NW and N of ENC, which should lower the risk of deep convection, and keep any severe thunderstorm risk low. In fact, some guidance suggests most of Wednesday will be dry. We'll continue to advertise isolated to scattered showers and thunderstorms Wednesday, but the signal doesn't look that good for appreciable rainfall. This could setup elevated fire conditions later in the week, especially with how dry it has been over the past few weeks.
A cold front will move through the area Wednesday evening, ushering in a much colder and drier airmass. The passage of the front will also spell the end of any rainfall chances.
Thursday through Monday As of 130 AM Tuesday,
Key Messages
- Cold and dry conditions expected on Thanksgiving
A much colder, and very dry, post-frontal airmass will settle into the Carolinas over the Thanksgiving holiday. Sprawling high pressure overhead should setup a couple of nights of excellent radiational cooling conditions, supporting below to well below normal temperatures. The coldest night is expected to be Friday night, with lows falling into the 20s inland, and 30s along the coast. Of note, guidance has trended colder during the Thursday - Saturday period, and the forecast reflects this trend.
Late in the weekend and into early next week, the cold airmass is forecast to shift away from the area as deep southerly flow redevelops ahead of a positively-tilted upper trough over the western/central U.S. This type of upper level pattern often favors significant differences among deterministic guidance. Therefore, confidence is lower regarding how quickly moisture and rainfall chances will increase. For now, the forecast will reflect warming temperatures with a modest chance of showers.
12z Tuesday through Saturday As of 640 AM Tuesday,
Key Messages
- Small opportunity for sub-VFR conditions along the coast this morning
- A chance for sub-VFR conditions tonight and Wednesday with increasing moisture and showers ahead of a cold front.
High pressure slides offshore today. Low level flow veers to SE overnight allowing for increasing moisture with onshore flow developing. Stratocu has started to spread onshore this morning, first across the southern coast then spreading nwd across the rest of ENC through the day today. Current thinking is that cloud bases will be 3000-4500 ft along and east of US 17, with more scattered low cloud coverage farther inland. This should result in VFR remaining predominant inland, but coastal areas could see some periods of MVFR ceilings this morning through the afternoon. Will keep KOAJ and KEWN at VFR for this TAF issuance as confidence is not high enough to include MVFR ceilings. Early tonight, a shortwave moving along the coast brings a slight chance of rainfall and MVFR ceiling potential. Further inland, ahead of the cold front increasing low level moisture brings MVFR to potentially IFR ceilings for the coastal plain. The eastward extent of the sub-VFR conditions is still uncertain, leading to low confidence in the TAFs for PGV and ISO overnight into early morning Wednesday. Added VCSH for ISO and PGV overnight, with lower confidence of TS preventing a VCTS in the TAFs with this cycle.
Outlook: An approaching frontal system will bring the next chances of sub-VFR conditions Wednesday, mainly in showers during the afternoon and evening hours. There is also a 15-30% chance of thunderstorms Tuesday night into Wednesday. After cold front moves through late Wednesday, VFR conditions are expected to return as high pressure builds in.
As of 130 AM Tuesday,
Key Messages
- Increased risk of elevated winds and seas from Tuesday night through Friday
- Small Craft Advisory now in effect for portions of the coastal waters
- Thunderstorms possible tonight
A coastal trough has developed over the southern waters this morning, with a modest E to SE flow of 5-15kt developing around it across most ENC waters. This trough is forecast to lift north through the day today, with the flow becoming predominantly southerly by this afternoon. The southerly flow then builds further tonight into Wednesday as the gradient tightens ahead of an approaching cold front. A period of moderately strong southerly winds of 15-25kt is expected this evening through Wednesday evening. Over the warmer central and southern coastal waters, occasional gusts of 30-35kt appear possible on Wednesday. Given an increasing signal for 25kt+ winds, a Small Craft Advisory has been issued for the coastal waters from Oregon Inlet south through Surf City. For now, this advisory will just be focused on the pre-frontal southerly winds and elevated seas. Additional marine headlines may be needed for the post-frontal northerly winds later in the week.
Seas of 2-3ft this morning are expected to build to 3-6ft by tonight, then further build to 4-7ft on Wednesday. The highest seas are expected from Cape Hatteras south.
As a warm front lifts north through the area tonight, there will be a modest risk of thunderstorms, mainly over the central and southern coastal waters and the eastern Pamlico Sound.
Lastly, warm and moist air overspreading the cooler shelf waters may lead to a period of marine fog impacts this evening and tonight before the strongest winds arrive.
Outlook: A post-frontal surge of northwesterly winds is expected late Thursday into Friday, with a period of 20-30kt wind gusts expected for most, if not all, waters. Later Friday through Saturday, high pressure is forecast to build in with winds and seas laying down.
Nc, none. Marine, small craft advisory from 7 pm this evening to 7 am EST Thursday for amz152-154-156-158.
