Key MESSAGE 1, Little change to the forecast reasoning with medium range guidance continuing to converge on a solution for the mid to late-week period, but notable differences remain. Where guidance is fairly well clustered is with an amplified upper trough that will be shifting east out of the Central U.S. While there is still some potential for a cutoff low to develop, most guidance have now trended towards more of a progressive and open wave as it moves through the Eastern U.S. Guidance differ on the timing, which leads to differences in precipitation placement, temperatures, etc. But, most guidance is now centering on the best chance of showers and thunderstorms coming Thursday and/or Friday. Of note, some guidance are showing anomalous moisture and higher-than-normal instability for early November. This would support the potential of some higher rainfall rates and totals should this materialize. It may even support at least a marginal risk of strong to severe thunderstorms. While there is some synoptic support for this potential, machine learning guidance doesn't show that strong of a signal. It's something worth keeping an eye on as the evolution of the upper level, and surface, pattern become more clear.
The other aspect of the forecast that appears to be coming more clear this week is the potential for above to well above normal temperatures, especially Wednesday and Thursday. While record highs may not be broken, warming low-level thicknesses in advance of the approaching trough should support highs warming into the 70s, with some low 80s possible inland. Meanwhile, overnight lows are forecast to be closer to our normal highs for this time of year. Some record warm lows may be in jeopardy. For reference, normal highs are around 70 in early November, with normal lows in the 40s inland and 50s along the coast.
18z Sunday through Friday Forecast confidence is high over the next 24 hours.
Pred VFR conditions expected through the TAF period. Moderate NE winds continue across rtes this afternoon but will diminish this evening, especially inland where many locations will likely decouple. Probs for fog remain low tonight with mid and high clouds expected to limit radiational cooling, though cannot rule out patchy shallow fog if sufficient breaks in the clouds develop. Refs has the highest probs around 20-40% across the western portions of the Albemarle/Pamlico Peninsula, though remain less than 20% at the TAF sites.
Outlook: While the weather pattern doesn't drastically change, a moistening easterly flow and a weak upper level wave may support a risk of sub-VFR CIGs and SHRA Monday through Monday night, especially for coastal TAF sites. Confidence in this risk developing is moderate. Drier air is expected to move in on Tuesday, likely lowering the risk of sub-VFR CIGs and SHRA.
A pinched surface gradient remains in place between a coastal troughing offshore and a strong surface high anchored over the Mid-Atlantic States. This has supported elevated northeast winds of 15-25kt through much of the day, highest across the southern waters. Guidance showing gradients relaxing this evening with NE winds around 5-15 kt overnight into Monday. Seas remain around 3-5 ft with up to around 6 ft across the outer waters south of Cape Hatteras. Have cancelled the Small Craft Advisory for the central waters but continue south of Ocracoke through 7 pm.
Outlook: Coastal troughing is forecast to remain intact through at least the middle of the week, with the strongest gradient and highest winds focused across the central and southern waters. The coastal trough may drift inland by Wednesday with more of a dominant easterly flow developing for most waters. The flow then begins to become southeasterly by Thursday in the wake of the inland-advancing coastal trough. Guidance continue to keep probs for 25kt+ winds low through Thursday. However, there is a broad signal for low pressure development over the Southwest Atlantic later in the week. Should this occur, there may be an accompanying risk of 6ft+ long-period swell development.
Nc, none. Marine, small craft advisory until 7 pm EST this evening for amz156- 158.
