textproduct: NWS Wilmington

WHAT HAS CHANGED

Updated aviation discussion for the routine 06Z issuance.

Rain chances have decreased for inland areas this afternoon.

KEY MESSAGES

1) Minimal rain chances expected today ahead of a cold front this weekend.

2) Scattered showers and storms remain possible through the end of the forecast period.

DISCUSSION

KEY MESSAGE 1...Minimal rain chances expected today ahead of a cold front this weekend.

Inverted trough north of the Bahamas will push a tongue of increased moisture northwestward early this morning and through the afternoon. Low level vorticity signatures weaken as the feature approaches the coast which lowers confidence in large-scale PoPs due to lacking upper level support. However, the additional moisture should increase the depth of developing cumulus along the sea breeze during the late morning and early afternoon. Surface dew point depressions are still marginal for climatological sea breeze development, so the latest forecast maintains a PoP forecast of around 20%. Latest HREF guidance supports this forecast update with only a few members producing stray showers, primarily near the Cape Fear. Poor mid level lapse rates result in a low chance of thunderstorms.

Inland, a cold front will be drifting southward through the central Carolinas and southern VA. This will supply lift ahead of a warm, humid air mass. Latest HREF/REFS keep the bulk of convection west of I-95 and nearly outside of our area completely. This has been rater consistent over the last several days in deterministic models. The slower moving front is a favored solution based on the last few hours of surface analyses. PoPs have been cut as a result along the I-95 corridor through this evening. If any convection sneaks southward, lapse rates will remain poor, therefore SPC's determination is that severe weather appears unlikely.

KEY MESSAGE 2...Scattered showers and storms remain possible through the end of the forecast period.

The cold front will drop into the area Friday before being pushed back to the north Friday night. For this reason highest POPs will start up along the afternoon sea breeze before transitioning to our N/NW areas closer to the front later in the day. The main driver for precip will then return to the daily sea breeze with a more typical widely scattered shower/thunderstorm setup going from the coast in the afternoon to inland in the evening. POPs have been decreased to reflect this pattern throughout the entire period.

AVIATION /06Z THURSDAY THROUGH MONDAY/

Light boundary layer winds, clear skies, and near-surface moisture should produce areas of fog overnight. Some fog could be dense, best chance will be east of I-95. Confidence is slightly lower for fog inland, but conditions don't support a restriction-free night.

Bermuda high maintains summer-like conditions today. A stray shower is possible along the sea breeze, mainly at ILM late this morning and into the early afternoon. A shower or thunderstorm may impact FLO/LBT early this evening, but HREF/REFS guidance suggests that meaningful probabilities remain west of I-95.

Extended Forecast... IFR possible for Friday morning, mainly inland due to a few showers along the coast. Shower and storm chances increase on Friday. Air mass thunderstorms return on Saturday through Monday with restrictions possible in morning fog/stratus and afternoon showers and storms.

MARINE

Through Tonight... High confidence in summer-like conditions due to prevailing Bermuda high pressure. Southerly winds will mostly be 10- 15 kt or less, although locally higher near the Gulf Stream beyond 20 nm tonight and near the coast due to the sea breeze this afternoon. Waves will continue to be dominated by 2-4 foot, 8-9 second southeast swells.

Friday through Tuesday...Predominantly southerly winds under Bermuda high pressure as a front fails to cross the coastal waters from the north on Friday, speeds generally 10-15 kts. Seas 2-3 ft out to 20nmi with 4 ft 20-60nmi. As we enter a summer-like airmass, rain and thunderstorms will be possible day to day, primarily along the sea breeze and then later during the overnight hours.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...None. MARINE...None.