textproduct: NWS Wilmington

WHAT HAS CHANGED

The 12Z aviation discussion was updated.

KEY MESSAGES

1) Much needed rainfall expected through the early morning hour and into the afternoon as a cold front moves through the area.

2)Showers on Wednesday associated with a cold front will be light and thus not bring any drought releif.

DISCUSSION

KEY MESSAGE 1....Much needed rainfall expected through the early morning hour and into the afternoon as a cold front moves through the area.

KEY MESSAGE 1 DESCRIPTION... The forecast area is finally getting some much needed rainfall thanks to a swath of high PWATs ahead/along the cold front which is progressing toward the central Carolinas early this morning. Developing low pressure off DELMARVA will push this boundary off the coast this afternoon. The deeper moisture has trended to hang around longer today with deeper drying noted in time-height cross sections generally after 18Z today. QPF is expected to range from 0.25-0.50 inches (less across portions of northeast SC. A few areas may be lucky enough to see an inch (current probabilistic rainfall amounts show about a 25-30% chance of an inch across coastal areas of southeast NC. While this rainfall is certainly helpful, it will not put much of a dent into the current drought conditions. Low-level moisture will be hard to scour-out along the coastal areas, thus mostly cloudy conditions will likely persist along coastal areas through at least late tonight. Otherwise, the NEly pressure gradient will tighten in the wake of the cold front and gusty NE winds are expected to develop this afternoon and carry into the evening.

KEY MESSAGE 2...Showers on Wednesday associated with a cold front will be light and thus not bring any drought releif.

KEY MESSAGE 2 DESCRIPTION... Precipitable water values shoot up to 1.4" on Wednesday ahead of a cold front. And while this sounds like potential good news given the current drought situation the overall QPF prospects appear minimal. This is both due the weakness of the front itself meaning that low level forcing is weak, and also to the fact that mid level flow remains westerly and with only minimal embedded vorticity. So similar to the low level forcing, the mid level forcing for ascent will also be minimal and most of the aforementioned PW will not be tapped.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

A cold front will continue to push southeast and southward across the area resulting in mainly -SHRA at the terminals through 18-21Z (west to east) timeframe. There is a high likelihood that IFR/MVFR CIGs will develop as the front moves through. CIGs are expected to improve at KLBT/KFLO generally after 20Z today, but it will take longer for the low level moisture to exit the coastal terminals. In addition, NEly winds are expected to become gusty in the wake of the front, especially at the coastal terminals.

Extended Forecast...Lingering MVFR CIGs remain possible through early Monday morning, mainly for the coastal terminals. There is some potential for low stratus or ground fog Tuesday and Wednesday nights, along with impacts possible from showers or thunderstorms on Wednesday.

MARINE

Through tonight...A cold front approaching the central Carolinas early this morning will move generally north to south across the coastal waters this afternoon. The flow in the wake of the front will veer to a N-NEly direction and increase to Small Craft thresholds for the coastal waters. Counter-current winds farther offshore will result in steep wave conditions there. The NEly fetch will persist through tonight with little improvement in the seas. Showers and thunderstorms are expected to increase in coverage across the waters, especially farther offshore where there is better instability. Locally higher winds and seas can be expected near any thunderstorms. The chance for storms will persist through tonight, especially across the offshore waters.

Monday through Friday... Wedge of high pressure still nosing in from the north on Monday for NE winds and choppy seas. Veering is then slated for Tuesday as the high weakens. After a period of light onshore flow a more typical S to SW flow resumes Tuesday night into Wednesday as a cold front approaches from the NW. Offshore flow behind the frontal passage for Thursday and Friday as another high builds in from the NW.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...None. MARINE...Small Craft Advisory from 5 PM this afternoon to 6 PM EDT Monday for AMZ250. Small Craft Advisory from 8 PM this evening to 6 PM EDT Monday for AMZ252-254-256.