Arctic front tracks across ENC and pushes offshore by this morning with high pressure building back into the Carolinas later today. Another cold front moves through Thursday night. High pressure briefly builds in on Friday, followed by additional cold front passages over the weekend. A coastal low, or two, will be possible during this time as well.
Today As of 10:15 AM Wednesday, The forecast remains on track with no major changes made during the morning update.
Previous Discussion, As of 7 AM Wed, Previously mentioned front has made its way across the region as of this update and is now just to the south. Biggest challenge has been near term temps given the front continued to slow as it tracked across the area but now that the front is through and CAA has begun in earnest forecast should continue to track well today.
As we get into today, upper level Jet Streak will finally push off the coast while a broad positively tiled trough extending SW'wards from the Northeast to the Plains will continue to gradually push SE'wards. In the mid levels, shortwave across the Mid-Atlantic will gradually push offshore today while a second and slightly stronger shortwave in the Southern Plains pushes SE'wards into the Deep South dragging the upper level trough closer to the coast. While the upper level pattern remains highly complex, at the surface a much simpler solution emerges. Cold front pushes offshore later this morning with NW'rly winds remaining elevated until early afternoon before easing as high pressure builds in from the west. With ongoing CAA expect temps to struggle to get out of the upper 30s today, though we will remain dry.
Tonight As of 315 AM Wed, Broad upper troughing remains over the Eastern Seaboard as southern stream shortwave continues to drag it SE'wards towards the coast tonight. At the surface high pressure ridging will continue to build overhead allowing for clear skies and light to calm winds tonight. This will set the stage for great radiational cooling. Just after sunset expect temps to quickly tank with lows getting into the teens to mid 20s across ENC which is on the lower end of guidance. While this would typically set the stage for potential Cold Weather Advisory conditions, given the lack of wind tonight the Apparent temp should remain just above 15 F. With HREF probs showing a 20% or less chance of Apparent T's at or below 15 F this lends confidence we will remain headline free this evening.
Thursday through Tuesday As of 300 AM Wednesday,
key messages:
- Another round of well below normal temperatures expected next week. Wintry precipitation potential less certain
Thursday: A shortwave will translate east from the Great Lakes to the Mid-Atlantic on Thursday, which will eventually push a cold front east across the Carolinas Thursday night. Ahead of the front, a warming west to southwesterly flow should lead to a noticeable boost in temps compared to today. In fact, with a bit of downslope warming possible, I trended highs up compared to the previous forecast. This also jives with guidance trending warmer. The net effect is that this puts the area closer to climo for mid-January. Thursday night's cold front will knock temperatures back down, but perhaps not drastically so.
Friday-Sunday: Ridging aloft and high pressure at the surface will briefly dominate the weather across the region on Friday. This will keep the weather cool and dry during the day.
By Friday night, high pressure will shift offshore, setting up a moistening return flow. Southwesterly moisture advection will ramp up in earnest late Friday night into Saturday as a dampening shortwave approaches from the west. This wave, while forecast to weaken, will glance the coastal Carolinas Saturday into Saturday night. Despite the weakening wave, guidance continues to show a period of strong WAA and increased large- scale forcing for ascent overlapping with a notable plume of moisture off the Gulf of Mexico. In light of this, deterministic and ensemble guidance continue to paint a fairly solid signal for widespread rain showers on Saturday, and the forecast will reflect this expectation. One caveat worth pointing out is that a weak coastal low may develop near, or just offshore of the Carolinas. Should this occur, showers may tend to be focused closer to the coast, and recent guidance has trended a bit drier further inland. We'll continue to monitor trends as the current forecast may be overdone on the rain risk inland. Because of the strong WAA, Saturday and Saturday night's precipitation should be all rain.
Attention then turns to Sunday and Sunday night. Saturday night's cold front is now forecast to get hung up just offshore, setting up a favorable baroclinic zone for the potential development of another coastal low as yet another shortwave approaches from the west. In light of this, recent guidance has trended towards a modestly deeper SFC low. Where guidance differ is with the track, and speed, of the low. This is important because colder air is forecast to begin filtering into the area, especially by Sunday night. At this point, the most likely scenario appears to be a second round of rain Sunday into Sunday night. However, the guidance showing a slower SFC low track could introduce a rain ending as a brief period of snow as the colder air filters in.
Monday-Tuesday: By far, the main message during this timeframe will be the cold. Deterministic and ensemble guidance and other forecast aids continue to show a strong signal for well below normal temperatures next week as an Arctic airmass spills south and east out of Canada and into the central/eastern U.S. During this time, some forecast aids suggest the potential for record low temperatures. There is the potential for some areas to see 24+ consecutive hours below freezing which is notable for this area.
What continues to be a point of disagreement in the guidance is whether or not moisture will overlap with the cold airmass. There continues to be a signal for some wintry precipitation next week across parts of the Southeast U.S., but ensemble probabilities continue to remain low. This just means there is a lot of model spread, so stay tuned.
17z Wednesday through Sunday Through Thursday afternoon As of 12:20 PM Wednesday, High confidence in VFR flight cats through the period continues. Today, 10-15 kt NWerly winds will gradually back to the SW and become light to calm overnight across the coastal plain. Winds across the OBX will stay more Werly overnight around 5-10 kt. Tomorrow, winds will be SWerly around 10-15 kt. Mostly clear skies will persist through the period.
Thursday through Sunday As of 300 AM Wednesday,
key messages:
- Increased risk of sub VFR conditions Saturday and Sunday
A cold front will move through ENC Thursday night, and may be accompanied by a modest bump up in northwesterly winds. High pressure then builds in with dry conditions and lighter winds Friday. Southerly winds are forecast to increase Friday night into Saturday, especially closer to the coast. Inland airports may hold onto a northerly wind depending on the track of a weak surface low that is forecast to move through the area. This low will bring an increased risk of SHRA and sub VFR conditions. The TSRA looks low for Saturday. An additional round of RA is possible on Sunday, along with a continued risk of sub VFR conditions.
Through Wednesday night As of 705 AM Wednesday, Have ended the gale warnings across the N'rn and S'rn Coastal Waters and replaced these with small crafts. Have also expired the small crafts along the inland rivers as winds will likely remain just below 25 kts this morning. Otherwise still expecting winds to quickly ease this morning with the remainder of the gales falling off within the next hour or two.
Cold front currently extends E-W across Oregon Inlet towards Martin County this morning. Current obs generally have 10-15 kt W'rly winds across our inland sounds and rivers with gusts near 20 kts south of the front with 15-20 kt NNW'rly winds with gusts up to 25-30 kts noted behind the front across our northern sounds while along the coastal waters W to NWrly winds at 20-30 kts with gusts of 35-40 kts have been seen. Expect winds to peak around daybreak and then gradually ease from NW to SE later this morning and early this afternoon as the aforementioned front pushes offshore and high pressure builds in from the west. Winds should become NW'rly across all waters after daybreak and then decrease to 10-20 kts with 25+ kt gusts remaining relegated to our coastal waters by this afternoon. As a result expect to end the coastal gales by about midday and inland SCA's later this morning. Winds continues to ease tonight as high pressure builds in from the west down to 5-10 kts. Seas are currently about 4-8 ft this morning and will continue to remain elevated through the afternoon before falling to 2-5 ft late tonight thus ending any leftover SCA's across our waters.
Thursday through Sunday As of 300 AM Wednesday,
key messages:
- Multiple opportunities for elevated winds and seas through the weekend
An active weather pattern will continue to support multiple opportunities for elevated winds and seas through this weekend. The periods that stand out the most are Thursday, and again Saturday and Sunday. Those days all carry a high chance of 25kt winds, with some waters potentially reaching gale-force winds. Stay tuned for updates on possible marine hazards through the next several days.
Nc, none. Marine, small craft advisory until 10 pm EST this evening for amz150. Small craft advisory until 4 am EST Thursday for amz152-154. Small craft advisory until 1 pm EST this afternoon for amz156- 158.
