Schc to Chc of precipitation tonight behind a warm front. A weakening cold front crosses Wednesday afternoon followed by a reinforcing cold front sweeps east across the area Wednesday night putting an end to unsettled conditions, though breezy NW'rly winds are expected behind this front. Large high pressure then builds in from the west with below avg temperatures forecast from Thanksgiving on into the weekend as reinforcing shots of cold air infiltrate the region. Next potential frontal system impacts the area late this weekend into early next week.
Until 6 am Wednesday morning As of 2200 Tuesday,
Key Messages
- Above normal temperatures tonight - Light rain through overnight, best chance along immediate coast
Deepening trough aloft over the Upper Midwest will push east into the Great Lakes while the upper level jet strengthens across the Mid- Atlantic tonight. At the same time weak mid level shortwave is forecast to overspread the region in the wake of warm front that has lifted through ENC, currently located N of DelMarVA peninsula. Another warm front currently wavering across GA, SC, and Nward up the coast will also lift through tonight after midnight. The combination of the glancing wave, sloping ascent over the front, modest WAA, and increased moisture advection should support increased cloud cover and a quick round of scattered showers and isolated thunderstorms into tonight. The greatest chance of showers looks to be focused along the coast where low- level convergence is maximized between offshore High and the warm front. While weak instability across ENC may support a few thunderstorms tonight, the lack of stronger lift and instability should limit any severe thunderstorm risk. Given the ample cloud cover don't expect to cool off much tonight as lows get into the low to mid 60s, which are typically the MaxTs for this time of year.
6 am Wednesday morning through Wednesday night As of 2 PM Tuesday, Neutrally tilted upper level trough over the Great Lakes on Wed will continue to push east becoming centered across the Eastern Seaboard overnight Wed. Will have another weak shortwave track across the region Wed afternoon in association with a surface cold front, however the strongest forcing will likely be displaced to the north and west closer to the parent surface low and upper level troughing. At the surface, ENC will remain warm sectored through much of Wednesday out ahead of an approaching cold front. This will keep southerly flow and building low level thicknesses in place supporting highs in the 70s across ENC which is well above normal for this time of year. 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.
While relatively deep moisture will be in place across ENC through the day on Wed with PWATs generally remaining around 1.0-1.5 inches, and instability generally around 500 J/kg which normally would support some scattered thunderstorms across the region, given the lack of forcing with the strongest forcing remaining to the north and west, still only expecting isolated showers and thunderstorms across ENC through the day Wednesday. However, will note much of the day could be dry overall and with weaker instability noted will likely not see stronger storms. This then likely results in little in the way of appreciable rainfall across ENC through the day which could setup elevated fire conditions later in the week, especially with how dry it has been over the past few weeks.
Aforementioned cold front quickly sweeps across ENC overnight Wed ending any precip threat. But this will bring clearing skies and CAA across ENC Wed night. With this in mind, low temps will likely crater after midnight and will be about 15-20 degrees colder than Tue nights lows with widespread upper 30s to low 40s noted inland Thurs morning and mid 40s noted along the OBX.
Thursday through Tuesday As of 2 PM 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.
03z Wednesday through Sunday As of 1840 Tuesday,
Key Messages
- A chance for sub-VFR conditions tonight and Wednesday with increasing moisture and showers ahead of a cold front.
- LLWS possible late tonight into Wednesday morning.
Moist southerly flow will continue ahead of a cold front through the TAF period. Pred VFR across rtes this evening but precip chances increase overnight and Wednesday bringing the potential for sub-VFR conditions, especially in heavier showers and thunderstorms. Guidance indicating the best chance (60-80%) for sub-VFR conditions will be after midnight tonight through around daybreak with low stratus and light fog possible. Conditions are also favorable for sea fog development tonight and Wednesday morning that could impact terminals along the immediate coast but will not impact the TAF sites. Also, a strengthening low level jet overnight will bring the potential for LLWS concerns late tonight into Wednesday morning, mainly 9-13z. S to SW winds will gust to around 20 kt this afternoon and to around 25 kt late Wednesday morning and afternoon. Weakening cold front crosses WED afternoon bringing SChc of some showers and lower CIGs in a SW-NE band moving from W to E. Cigs could reach MVFR levels, ~1100-1500EST inland, 1330-1600 EWN/OAJ. Terminals along the immediate coast should be spared from subVFR CIGs with the showers waning and clouds continuing to lift in the late afternoon/early evening.
Outlook: A reinforcing cold front will push across rtes Wednesday night bringing clearing skies and pred VFR conditions that will continue through the remainder of the week as high pressure builds across the area. The high moves offshore Saturday night with precip chances increasing on Sunday.
As of 210 PM 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 and the Pamlico Sound - Gale watch now in effect for portions of the Coastal Waters between Wed afternoon and Thursday morning
- Thunderstorms possible tonight
While coastal showers along the Crystal Coast have ended with the previously mentioned coastal trough dissipating, latest obs across our waters show widespread S'rly winds at 10-20 kts with seas along our coastal waters remaining around 2-4 ft. Do expect marine conditions to worsen tonight with gusts up to 25 kts expected across the coastal waters south of Oregon Inlet. As a result have kept SCA's up across these waters starting tonight. Slightly lighter winds will be noted elsewhere given cooler water temps with gusts up to 15-20 kts expected. As we get into tonight warm front will lift north across the region veering winds slightly to a SW'rly direction. The southerly flow then builds further on Wed and Wed evening as the gradient tightens ahead of an approaching cold front. Latest trends suggest while coastal waters north of Oregon Inlet and inland waters will see winds around 10-20 kts with gusts near 25 kts, the coastal waters along the Gulf Stream could see a gusts as high as 30-35+ kt Wed afternoon and overnight. Given the continued signal with ECWMF/HREF probs of gale force gusts generally around 40-70% across these waters and RRFS wind gusts noted around 35 kts across these waters elected to go with a gale watch starting around 3PM Wed and going into early Thurs morning from Surf City up to Oregon Inlet. Will note chances of seeing gale force gusts will likely be relegated to the coastal waters 10+ NM out along the Gulf Stream but the threat is there. Even if the recent trend backs off, strong small craft advisory S'rly winds are expected. Have also added a SCA across the larger Pamlico Sound where gusts up to 25 kts will be possible Wed afternoon. For now, these headlines 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 2-4ft this afternoon are expected to build to 3-6ft 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 3 pm Wednesday to 4 am EST Thursday for amz135. Small craft advisory until 3 pm EST Wednesday for amz152-154- 156-158. Gale watch from Wednesday afternoon through Wednesday evening for amz152-154-156-158.
