textproduct: NWS Wilmington

WHAT HAS CHANGED

Forecast challenges tonight include the potential for inland low stratus and fog to develop late, and also hammering out precisely when offshore showers will move onshore. MOS and NBM blends have performed poorly the last two nights with fog, overpredicting its coverage. Moisture depth is better tonight with light easterly flow well-established, however slowly increasing boundary layer winds late tonight may lead to low stratus rather than fog. This potential will be monitored throughout the evening.

The 18z RRFS is considerably faster than the 12z HREF or 22z NBM with the onset of showers tonight across the coastal Cape Fear region. I've maintained the slower timing in-line with our previous forecast with 20-40 percent chances sliding onshore by daybreak.

KEY MESSAGES

1) Unsettled weather Tuesday through Thursday will give way to cooler weather.

DISCUSSION

KEY MESSAGE 1...Unsettled weather Tuesday through Thursday will give way to cooler weather.

Previous forecast remains on track for this week with guidance showing good agreement on an upr-level trough diving into the Mid Atlantic during the mid week period, leading to elevated chances for rain (50-60% PoPs) Tuesday through Thursday. Not expecting enough precip to put a dent into the drought, but isolated pockets of heavy rain are possible on Tuesday...the Weather Predication Center has a marginal risk (threat level 1 out of 4) for excessive rainfall over part of the area. Environment is not really supportive of strong or severe storms, so while lightning will be a low risk, severe weather potential is very low. Thereafter, the upr-level low will cut off east of the Mid Atlantic region allowing for cool and dry advection into the area, leading to a period of slightly below normal temperatures for the first time in quite a while late week into the weekend.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

Light winds and VFR conditions should continue through about 08z before there inland conditions begin to deteriorate. There is a moderate to high potential for IFR ceilings and/or visibility to develop at KFLO after 09z Tuesday. A moderate potential exists for similar impacts at KLBT. Coastal airports should remain VFR although there is a low potential for spotty showers to push onshore before daybreak with brief MVFR ceilings or visibilities possible.

After daybreak, clusters of showers and possibly thunderstorms will spread slowly westward across the area. The highest potential for impacts is expected between 14-19z at the coastal airports. Inland airports will have a low to moderate potential for impacts mainly after 18z.

Extended Outlook...There is a good chance for MVFR/IFR ceilings at times in showers/thunderstorms/rain through Thursday.

MARINE

Sub-SCA conditions continue through at least Tuesday night with a fairly weak pressure gradient over the area. A low pressure system will develop offshore starting mid week leading to likely SCA conditions late Wednesday through Friday with even some gale gusts possible, mainly over the 20-60 NM waters, depending on how close to the coast the low develops and how quickly it strengthens. For now, expect mainly SCA headlines. An improving trend then for marine conditions into the weekend.

ILM WATCHES/WARNINGS/ADVISORIES

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