textproduct: NWS Wilmington

WHAT HAS CHANGED

Marine headlines have been reconfigured to expire the Gale Warning for the offshore NC waters, shorten the Small Craft Advisory for the Horry County coastal waters, and lengthen the Small Craft Advisory for the NC coastal waters. Also, forecast highs today have been tweaked 1-2 degrees higher.

KEY MESSAGES

1) A deep layer of northerly winds will maintain a dry Canadian airmass through the remainder of the week.

DISCUSSION

KEY MESSAGE 1....A deep layer of northerly winds will maintain a dry Canadian airmass through the remainder of the week.

Persistent northerly low and mid level flow continues over the Carolinas between a ridge over the southern Plains and a nearly stationary low centered about 200 miles east of the northern Outer Banks. GFS HYSPLIT back-trajectories reveal the air parcels in our boundary layer this afternoon were 4-5km aloft over northern Canada 5-6 days ago, crossed 1-2km over the Great Lakes on Saturday, and then descended to near the surface over PA and the Mid Atlantic region yesterday.

Models show this pattern changing very little over the next few days which should maintain dry weather, clear skies, and generally below normal temperatures. The warmest day of the week may end up being today with mid 70s now forecast across most of the area. That's very close to normal for mid October.

New Canadian high pressure will expand south across the Great Lakes late this week. As the high moves south this weekend, our wind directions may veer easterly enough to bring more humidity onshore, but with sufficient ridging continuing aloft to maintain dry weather.

AVIATION /06Z TUESDAY THROUGH SATURDAY/

VFR conditions will continue over the coming 24 hours. The only aviation weather concern will be winds. Increasing winds at 1500-2000 feet AGL should reach LLWS criteria over KILM now through daybreak. These winds will mix down as surface temperatures rise after daybreak with gusts to at least 20 knots expected throughout the day. Surface winds should die down again this evening, but there is some risk LLWS could redevelop, particularly along the coast affecting KILM, KCRE, and KMYR.

Extended Outlook...VFR will continue through the period. Breezy northeasterly winds could gust to 25 knots at times Friday and Saturday.

MARINE

Today through Saturday...1003 mb low pressure centered about 200 miles east of the northern Outer Banks is shown by the models to move little while deepening by another 5-8 mb over the next 36 hours. This should maintain breezy north winds across the local coastal and offshore waters. Gale-force gusts have ended across our North Carolina 20-60 mile offshore zone, so the Gale Warning is being allowed to expire on schedule.

Even with slowly weakening local winds, marine conditions will remain rather rough for the next few days as a large zone of strong northerly winds off the Mid Atlantic coast maintains large seas across our area. Seas across the South Carolina nearshore waters should improve some today and tonight, but 6 foot seas should continue through all of Wednesday for our exposed portions of the North Carolina coastal waters near Cape Fear.

Looking later in the week: high pressure nosing south from Canada Friday should lead to increasing northeasterly winds with seas likely to surge back over 6 feet again across the coastal waters.

ILM WATCHES/WARNINGS/ADVISORIES

NC...High Risk for Rip Currents through this evening for NCZ108. High Surf Advisory until 8 AM EDT this morning for NCZ108. SC...Beach Hazards Statement through this evening for SCZ056. MARINE...Small Craft Advisory until 6 PM EDT Wednesday for AMZ250-252. Small Craft Advisory until 8 AM EDT this morning for AMZ254. Small Craft Advisory until 8 PM EDT this evening for AMZ256. Gale Warning until 2 AM EDT early this morning for AMZ280.