textproduct: NWS Wilmington

WHAT HAS CHANGED

A Small Craft Advisory has been issued for the coastal waters tonight through Saturday night.

KEY MESSAGES

- 1) An Arctic cold front arrives Saturday. A Cold Weather Advisory will be needed Saturday night.

DISCUSSION

KEY MESSAGE 1...An Arctic cold front arrives Saturday. A Cold Weather Advisory will be needed Saturday night.

KEY MESSAGE 1 DESCRIPTION... One final jet max will rotate around the southern periphery on the through in the NE Saturday into Sunday. Low pressure develops well off the MidAtlantic coast, driving an Arctic cold front through the Carolinas Saturday. Temperatures at 850mb will bottom out at -7C to -12C from south to north. Saturday night's lows will be near 20 away from the beaches with some upper teens over northern zones. Even as the gradient relaxes considerably the few kt of wind that remain the apparent temperature will drop below the Cold Weather Advisory thresholds of 15F for all but perhaps Williamsburg County.

AVIATION /06Z FRIDAY THROUGH TUESDAY/

There is a moderate potential for MVFR visibility developing at KFLO before sunrise, otherwise the potential for ceiling and visibility restrictions is low (but not completely zero) elsewhere. A weak ridge of high pressure will traverse the eastern Carolinas this morning bringing light winds. As the ridge moves offshore this afternoon wind speeds should increase, especially inland where gusts should exceed 20 knots at KFLO after 18z.

An arctic cold front will approach from the north after sunset. Although moisture is extremely limited with this feature, there may be enough depth of clouds for some showers or sprinkles affecting the KLBT and KILM airports between 22z Fri-02z Sat. As the front pushes through, winds will turn northwesterly at 10-12 knots as dry air pushes across the area. Low level wind shear conditions have some potential to develop after the front as models at 1000 and 2000 feet AGL show speeds increasing to 30kt and 40 kt, respectively, after 00-02z.

Extended Forecast...VFR.

MARINE

Through Tonight...A period of relatively light winds is expected this morning as a weak ridge of high pressure pushes across the area. Mariners wanting benign boating conditions should take advantage of this lull as much stronger winds are expected to develop tonight behind an arctic cold front. This front should push offshore between 8-11 PM followed immediately by a burst of northwest winds 20-25 knots gusting to 30 knots. A Small Craft Advisory is being issued for this period of adverse weather conditions which will last through Saturday.

Saturday through Tuesday... Arctic frontal passage early in the period to bring advisory-worthy wind gusts through Saturday and most of Saturday night. It is on Sunday when the gradient between the incoming high and the well offshore low eases for decreasing and slightly backing winds. Wind waves will be abating but there will be an emergence of some ENE swell energy. The surface high will sink to our south on Monday further veering the still lightening winds, falling to 10kt or less. The gradient will remain poorly defined on Tuesday bringing a further decrease in wind wave energy though spectral plots continue to show a 12 second easterly swell.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...None. MARINE...Small Craft Advisory from 10 PM this evening to 7 AM EST Sunday for AMZ250-252-254. Small Craft Advisory from 6 PM this evening to 7 AM EST Sunday for AMZ256.