textproduct: NWS Wilmington

WHAT HAS CHANGED

A Beach Hazards Statement was put out for southeast and east-facing beaches due to a strong longshore developing later in the day due to the increasing winds. Aviation discussion updated for 18z TAFs below.

KEY MESSAGES

1) Above-normal temperatures, low daytime relative humidity, and zero rain chances through early Saturday afternoon will lead to intensifying drought and fire weather concerns through the week.

2) No significant impact on drought conditions expected despite best rain chances/amounts in quite some time this weekend into next week.

DISCUSSION

KEY MESSAGE 1... Above-normal temperatures, low daytime relative humidity, and zero rain chances through early Saturday afternoon will lead to intensifying drought and fire weather concerns through the week.

Split upper level flow features near-normal 500 mb heights across the Carolinas between a ridge over the Great Lakes and a trough over Florida. Convergence downstream of the split is supporting surface high pressure off the Southeast U.S. coast, and this should remain in place through Friday.

This would be a summerlike pattern if not for dry air both within the boundary layer and aloft. Deep mixing via strong April sun has created inland mixing heights near 10k feet today. Mixing should be at least this deep again on Friday, transporting down very dry air from up within the subsidence inversion aloft. Daytime relative humidity inland from the seabreeze front should reach 20-25 percent again on Friday. This is the main weather concern as dry air in concert with increasing evapotranspiration rates as we push deeper into Spring will deplete already stressed soil moisture, groundwater, and river levels across the area. Fire weather concerns will continue until humidity increases, or better yet, until substantial rainfall occurs. UNCW-operated gauges on Smith Creek in Wilmington indicate rising salinity as salt water moves upstream in the past two weeks from the brackish Cape Fear River due to low flows.

Highs Friday should again reach the mid to upper 80s inland from the seabreeze which should keep beaches almost 10 degrees cooler. Seabreeze winds both this evening and again Friday afternoon/evening could reach 25 mph in gusts due to the substantial air temperature contrasts.

KEY MESSAGE 2... No significant impact on drought conditions expected despite best rain chances/amounts in quite some time this weekend into next week.

A frontal system will drag a cold front through late Saturday night into Sunday morning, with another weak front moving through Tuesday. These features will keep at least low rain chances in the forecast Saturday afternoon onwards with the best chances Saturday night and Tuesday. Confidence is increasing in the rainfall associated with the Sat/Sun front being ~0.25-0.5", with the NBM showing lower chances Tuesday for rainfall near 0.5", now near 10-20%. The front Tuesday may drop to our south before stalling near the area which could keep unsettled weather through the end of the period, adding additional rainfall though with much lower confidence in totals due to the possibility of convection and where the front ends up. WPC 7 day rainfall totals have our area in the 0.5-1" range, but this won't be enough to make up deficits. Embedded thunderstorms are possible with both frontal passages, but severe weather is not expected at this time. The frontal passage on Tuesday appears more favorable for low severe chances, but it is still uncertain at this time.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

VFR should continue for the next 24 hours. Today's seabreeze front should push inland through KCRE before 18z, KMYR by 19z, and KILM by 21z, increasing southerly winds to 15-20 knots through this evening.

Smoke from the large south Georgia wildfire will be transported northward across the Carolinas at times this afternoon through Friday. There's a low chance surface visibility could fall below 7 at local airports although this is not indicated in the TAFs at this time.

Extended Forecast...VFR conditions should prevail through at least midday Saturday. Showers associated with an approaching cold front could bring MVFR conditions Saturday afternoon through Sunday. Northeasterly wind gusts to 25 knots are possible behind the front Monday.

MARINE

Through Friday... High pressure off the coast will maintain a southwesterly synoptic wind through Friday. Away from seabreeze/ landbreeze influences wind speeds should average 15 knots. GFS Marine MOS Guidance at Wrightsville Beach suggests seabreeze- enhanced winds could reach as high as 21 knots early this evening before diminishing overnight. The same synoptic weather pattern will result in another strong seabreeze Friday afternoon where guidance suggests 23 knot peak winds Friday evening.

A small easterly 9-second swell will be overlaid by short-period wind chop with combined seas averaging 3 to 4 feet through Friday.

Friday Night through Tuesday... S/SW winds 15-20 kt expected through Saturday ahead of a cold front which drops through the waters late Saturday night. Winds then shift to the NE for Sunday and Monday, with a low chance of SCA conditions Sunday night over coastal waters with the NE surge behind the front. Gusts over the 20-60 NM waters up to 25-30 kt. Winds will come around to the SW through Tuesday ahead of another cold front. Seas 2-3 ft will increase to 3-5 ft where they'll stay through the period.

ILM WATCHES/WARNINGS/ADVISORIES

NC...Air Quality Alert until 8 PM EDT this evening for NCZ087. Beach Hazards Statement until 8 PM EDT this evening for NCZ106- 108. SC...Beach Hazards Statement until 8 PM EDT this evening for SCZ054- 056. Air Quality Alert until midnight EDT tonight for SCZ039-055- 056. MARINE...None.