Key MESSAGE 1, High pressure builds in from the west through most of this week with sunny skies. Building hts as upper ridge strengthens sends temps soaring through the 80s and nearing 90 for some interior locales (record high climate section below). A dry back door front is taking its time moving into nrn parts of ENC later today keeping most locations in the warm sector today with some increasing cloud cover and slightly cooler temps for extreme northern locales. The front quickly retreats north by early Friday with another surge of swrly flow ahead of much stronger front.
key message 2,
Uncertainty remains above average in regards to a coastal low forming along the cold front which will pass through the area late Friday night into early Saturday morning. While there are still three main camps as far as solutions go, confidence is trending up that a coastal low will form. The location and strength of that low remains in some question.
Once the low forms out over the gulf stream there are three main steering paths that models are hinting at right now. The most likely scenario at this time is that the low forms and stays over the gulf stream picking up strengths as it does so but remains in a fairly constant longitudinal range offshore. Most EPS ensemble members and some deterministic models such as the ICON, CMC and others fall into this camp but there is still considerable spread in the location and intensity details.
Other members along with the EC-AIFS model develop the low right along the coast and hold it there for a much more prolonged event. This scenario would likely have the highest impacts to coastal areas of eastern NC with several days of strong winds and high waves.
Finally, the GFS and its ensemble members remain an outlier in either not developing a low at all or developing it much later and much further east than any of the other scenarios. This remains the least likely to occur at this time.
Regardless of which scenario plays out, there is HIGH confidence of marine impacts, and potential for waves 7+ ft reaching portions of the OBX. Winds advisory potential exists for the OBX zones, as well as perhaps portions of the adjacent coastal mainland. Will have to watch for minor coastal flood concerns for srn portions of Pamlico Sound and the coastal areas of the OBX with the sustained NE flow.
KEY MESSAGE 3, Coolest and driest airmass for the fall season thus far builds in behind the front Sat night and beyond with temps taking a nosedive with highs in the 60s and lows in the 40s (inland) and 50s (beaches). However, depending how offshore the front makes it, could keep things a bit milder than fcst if some clouds advect in from offshore keeping the nighttime mins a bit warmer than advertised.
00z Friday through Tuesday Forecast confidence is moderate to high over the next 24 hours.
A weakening cold front will continue to slide slowly southwest through ENC this evening, potentially reaching as far as KOAJ before stalling. Increasing southerly flow will then force it to move back north overnight into early Friday morning. Behind the front, an area of MVFR CIGs has developed and this is expected to impact KPGV and KISO, but may also reach as far as KEWN and KMRH. Cigs will quickly improve once the front moves back north, but guidance differs on how quickly this transition will occur. Once the front is to the north of any TAF site, then VFR conditions should prevail. The one caveat through early Friday morning is the potential for reduced VIS in BR. Due to the uncertainties with the evolution of the front, it's unclear where winds will be the lightest and where low-level moisture will be the highest, as the areas with that overlap will probably have the greatest risk of sub-VFR VIS.
On Friday, southerly winds will become gusty at times, with gusts to 20kt likely.
Outlook (Sat through Mon): Strong and slow moving cold front brings widespread light rain on Sat, with sub VFR likely behind the front later Sat with frontal inversion developing, along with gusty north winds through the day Sat. Clearing skies Sat night with winds tapering off as high pres attempts to build in for the latter half of the weekend into next week.
Latest obs show continuing SW winds 5-10 knots gusting 15-20 kts at most locales with seas mainly 2-3 ft. Backdoor front has made it through the Albemarle and into the Croatan/Roanoke Sounds. To the north of the bndry, nerly breezes expected though remaining light, and to the south, generally swrly to srly continued light flow.
Outlook (Fri through Mon): A strong cold front has trended slower, now not expected to clear the waters until Sat, at which point it is likely to form a low pressure system offshore. Gale Watch is in effect beginning 12z Saturday for all waters except the southern rivers, although SCAs will be likely in these areas as well. Probabilities indicate high confidence in Gale Force Winds but likely not achieving storm force. Seas build quickly as well, with seas of 6-10+ ft appearing more likely through the weekend. Duration of gale force gusts is uncertain at this point and will likely bounce above and below the threshold well into next week, and there is potential for 6+ seas to linger as well.
Nc, high surf advisory from 2 pm Saturday to 8 pm EDT Monday for ncz203-205. Marine, gale watch from Saturday morning through late Sunday night for amz131-135-150-152-154-156-158-180-182-184-186-188-230- 231.
