textproduct: NWS Wilmington

WHAT HAS CHANGED

Forecast highs have been tweaked upward by 1-2 degrees today and Thursday. Forecast lows have been tweaked down by 1-3 degrees tonight. Daytime dewpoints have been adjusted downward today and Thursday which could yield minimum relative humidity of 25-30 percent both days.

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 flow continues over the Carolinas between a ridge over the southern Plains and deepening 999 mb low pressure almost 400 miles east of the Virginia coast. This low is expected to continue drifting north through Thursday before being shunted away to the northeast for the weekend. With high pressure in control of the weather locally, dry weather, clear skies, and generally below normal temperatures are forecast through the end of the week.

Changes to NBM blends mainly centered on widening diurnal temperature ranges over the next couple of days (adding 1-2 degrees to highs and subtracting a bit from lows) and lowering daytime dewpoints by up to 6 degrees F.

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. Recent models show showers may develop offshore where higher dewpoints will promote small convective instability beneath the subsidence inversion aloft.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

SKC and unlimited visibility will continue over the coming 24 hours. A layer of northerly 20 knot winds 1500-2000 feet AGL will mix down to the surface after 14z increasing surface winds to 10-12 knots through mid afternoon.

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

MARINE

Today through Sunday...999 mb low pressure centered almost 400 miles east of Norfolk, VA should drift northward along 70 degrees west longitude through Thursday. Recent models suggest the low should deepen by another 10-15 millibars during that time, but increasing distance from the Carolinas means it should have diminishing influence on our weather conditions.

North-northeasterly winds at 15-20 knots this morning should diminish this afternoon and generally remain 15 knots or less through Thursday. A considerable 11-second northeasterly backswell still present currently should diminish in height through Thursday, leading to slowly improving marine weather conditions.

A new area of Canadian high pressure will begin to nose south along the East Coast Friday which should lead to a tighter pressure gradient and increasing winds and seas for the weekend. Small Craft Advisory conditions should develop across the coastal waters Friday, and there is at least some potential for gusts to Gale force across the offshore forecast zones (20-60 miles offshore) beginning Friday night.

ILM WATCHES/WARNINGS/ADVISORIES

NC...Beach Hazards Statement from 6 AM EDT this morning through this evening for NCZ108. SC...None. MARINE...Small Craft Advisory until 6 PM EDT this evening for AMZ250- 252.