textproduct: Wakefield

WHAT HAS CHANGED

Updated Aviation discussion for the 00Z TAF.

Small Craft Advisories now in effect for the Chesapeake Bay from Smith Point to Little Creek through late tonight.

KEY MESSAGES

1) Scattered showers and isolated storms are possible Saturday afternoon and evening. Additional showers are possible Sunday evening through Monday.

2) Seasonable temps Tuesday through Friday with another chance of rain and potential storms Wednesday/early Thursday.

DISCUSSION

As of 730 PM EDT Friday...

KEY MESSAGE 1...1) Scattered showers and isolated storms are possible Saturday afternoon and evening. Additional showers are possible Sunday evening through Monday.

High pressure translates offshore late this afternoon into the evening hours with continued dry and pleasant weather expected. Temperatures warm into the mid and upper 70s on Saturday as surface winds become SSW or SW. Mainly zonal flow aloft will bring weak disturbances into the area Saturday afternoon and evening. Chance PoPs (40% or less) during the afternoon will favor the eastern third of the area. Some instability is noted on forecast soundings so a few rumbles of thunder cannot be ruled out late Saturday, especially for the MD Eastern Shore where CAM guidance shows the potential for a few stronger convective cores. Sunday looks to stay dry with temperatures rising into the mid 80s. Moisture increases substantially Sunday night into early Monday with the potential for more widespread rainfall on Monday. High temperatures tumble back into the 60s and 70s (coolest N/warmest S) on Monday. Forecast soundings show little to no instability with this wave so not expecting to have any severe weather concerns.

KEY MESSAGE 2...Seasonable temps Tuesday through Friday with another chance of rain and potential storms Wednesday/early Thursday.

Latest guidance shows low pressure and an associated cold front approaching Wednesday and crossing the region Thursday. Ahead of the front, low level southerly flow will bring increasing moisture into the area. Models are in general agreement showing this surface low to our north and west, keeping the local area in the warm sector. Showers and storms are possible Wednesday into early Thursday ahead of the cold front. Guidance shows a decent overlap of enhanced winds aloft and some instability, so a few stronger storms are possible during the this period. High temps mainly in the 70s with low in the 40s and 50s through the end of the week.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

As of 730 PM EDT Friday...

VFR conditions in place across area terminals will prevail through the 00z TAF period. High pressure moving over the region is resulting in mainly light and variable winds this evening. Winds will become SSE tonight/early Saturday, as the high slides offshore. Winds turn from the S-SW on Saturday, mainly 10-15 kt with gusts to 20 kt.

Outlook: A quick moving system will bring a potential for a few widely scattered showers and isolated storms Saturday afternoon, with best chances mainly along the coast. An area of low pressure approaches the region late Sunday into Monday, bringing the potential for additional showers and flight restrictions.

MARINE

As of 710 PM EDT Friday...

Key Messages:

- SCAs have been issued for the bay north of Little Creek this evening-tonight and low-end/marginal SCAs are possible across the northern Ocean.

- Primarily sub-SCA conditions prevail through this weekend, though elevated southerly winds develop tonight/Sat.

- Small Craft Advisories are likely Monday into Tuesday, with increasing N winds, as deepening low pressure moves offshore, followed by high pressure building in from the NW. The latest wx analysis depicted high pressure just offshore, with an increasing pressure gradient across the Ches Bay and coastal waters. SE winds have already increased to 15-20 kt across the lower bay with S winds occasionally gusting to around 25 kt across the northern coastal waters. The pressure gradient continues to increase this evening into tonight as the high shifts offshore. This will allow winds to turn to the south and increase to 15-20 kt with gusts to 25 kt. Given late afternoon obs reflecting the higher model guidance, with respect to wind speed, and the model guidance continuing to support a period of 15-20 kt winds with gusts up to 25 kt overnight across the Ches Bay, have expanded the SCAs to include the lower Ches Bay (apart from the mouth of the bay). Additionally, have extended the SCAs for the middle bay through 6 AM Sat. Still, boundary layer mixing will be poor over the waters given the WAA regime and there will be a difference in wind speeds in elevated sensors vs. lower level sites.

Across the northern coastal waters, a few gusts to around 25 kt have been noted mainly at Ocean City. However, the Delaware Bay Buoy offshore has not yet seen gusts to 25 kt and the limited buoy data (and model guidance) doesn't support 5 ft seas. As such, have held off on SCAs for the coastal waters at this time. Nevertheless, the continued, elevated southerly flow could eventually lead to ~5ft seas off the northern Ocean zones later Saturday, with a potential SCA possible there. Mostly benign marine conditions are then expected Saturday night and Sunday as the pressure gradient weakens as high pressure returns. The better chance for a more significant event arrives Monday into Tuesday, as low pressure deepens while tracking along an advancing frontal boundary, and continues to intensify offshore Mon night as the next area of high pressure builds in from the NW Tuesday. Northerly winds are anticipated, along with ample mixing, so SCA headlines are likely for most, if not all of the marine area.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory until 6 AM EDT Saturday for ANZ630-631. Small Craft Advisory until 4 AM EDT Saturday for ANZ632.