Key MESSAGE 1, A weak area of low pressure is forecast to develop along the front off the Southeast coast later today through Tuesday with offshore front continuing to move south. Nhc currently gives the low a 10 percent chance for tropical development. However, gradients between the low offshore and high pressure centered along the Mid-Atlantic coast will bring NE winds, leading to somewhat cooler temps across the region, especially NE sections.
Diffluence aloft and a weak vort max approaching the area could yet spark a few showers and maybe a storm, but with nerly flow in place, the coverage will be very slim, in addition to morning strato cu hanging on leading to a slow diurnal rise in temps today. Best chances will be across swrn zones with weak instability and shear in place. Upper ridging builds eastward Tuesday with subsidence aloft curtailing storm development, though could see a few shower or thunderstorms off the coast near the Gulf Stream.
KEY MESSAGE 2, Dangerous heat builds into the east coast late week into the weekend as upper ridging builds across the Eastern CONUS with H85 temps climbing to around 20-23C Thursday through Monday. This will bring and extended period of temps reaching the mid 90s to lower 100 degree range each day with the highest temps expected on Saturday and Sunday. Heat indices are forecast to reach 105-110 Friday through Monday.
NWS probabilistic Heat Risk values for Thursday have come down some but still reach a moderate to major risk of heat related illnesses. Major to extreme heat risk continue to be forecast Friday through Sunday with a 60-80% chance for major heat risk or higher on Friday, and 80-100% chance on Saturday and Sunday. The chance for extreme heat risk is around 60-80% on Saturday and Sunday with compounding days of heat with poor overnight recoveries. Those sensitive to heat and anyone planning on spending ample amounts of time outside later next week should continue to monitor the forecast trends as this potential heat wave would have impacts on the holiday weekend.
18z Monday through Friday MVFR strato cu was slow to lift this morning as ENC under nerly flow regime on backside of offshore low pres. This will limit afternoon shower and storm chances, and have only a vcsh mention at KOAJ where best chances are for any rain. Elsewhere, chances too slim for any mentionable rain. Winds will be light nerly through the TAF pd with the low offshore.
Outlook (Tuesday through Fri): Dry weather is expected to prevail with pred VFR conditions, but could see patchy fog and low stratus each morning.
A cold front is pushing across the waters early this morning with N to NE winds developing behind the front The front will push offshore and a weak area of low pressure will develop along the front while high pressure centered along the Mid-Atlantic coast. This will bring NE winds around 15-20 kt across the waters this afternoon through Tuesday morning. Could see a few gusts to 25 kt at times but not expected to be persistent enough to warrant a SCA for winds at this time. However, the stronger winds and prolonged NE fetch will bring seas with guidance bringing the central waters up to 5-7 ft this evening through Tuesday evening, and have issued a SCA for seas with this forecast package.
Outlook (Wednesday through Friday): The Bermuda high become dominant mid to late week with wind generally around 15 kt or less and seas around 2-4 ft.
Nc, none. Marine, small craft advisory from 8 pm this evening to midnight EDT Tuesday night for amz152-154.
