Marine Weather and Tide Forecast for Galesville, MD

KEY MESSAGES
- 1) Near record warmth and mainly dry conditions continue through Wednesday.

- 2) A strong front moves through the region late week, bringing strong winds and cold conditions.

DISCUSSION
KEY MESSAGE 1...Dry and very warm through Wednesday.

Weak high pressure and mid-level ridging will continue to dominate the forecast heading into the midweek period. The high itself will slide offshore later today allowing the mid-level ridge to buckle heading into Wednesday. Meanwhile, a series of shortwave disturbances will quickly slide from west to east across northern portions of the forecast region as a cold front drops south from the Great Lakes and Ohio River Valley. This front will touch off showers and perhaps a few thunderstorms Wednesday afternoon and evening, mainly in areas along and north of I-66/US-50 and US-48. A Marginal Risk (Level 1 out of 5) for severe weather is in place for portions of western MD, eastern WV, and the VA Highlands Wednesday afternoon where better instability will reside. Coverage overall will be isolated to scattered with damaging winds as the primary concern.
Most locations will remain dry through Wednesday afternoon given the timing of the front and residual dry air to work with as the ridge slowly buckles.

Before the front arrives, expect near record warmth this afternoon and again Wednesday. Highs today will reach into the low to mid 80s (mid 70s mountains). Lows tonight will fall back into the upper 50s and mid 60s. Highs Wednesday will be much warmer in the mid to upper 80s and potentially low 90s for areas south and east of DC.

Cooler conditions return briefly Thursday as more of a wedge like pattern settles in. This is due to a large surface high pressure system anchored over southern Ontario Thursday wedging south along the eastern face of the Appalachians. Expect cloudy conditions to prevail along with passing showers especially across the southern 2/3rds of the forecast region. Highs will return closer to normal with most locations in the mid to upper 60s. The CAD will quickly erode Thursday night into Friday ahead of the next front heading into the weekend.

KEY MESSAGE 2...A strong front moves through the region late week, bringing strong winds and cold conditions.

A low pressure system is forecast to track from the Great Lakes region into Canada Thursday night into Friday, pushing a cold front across the forecast area on Friday. This frontal system brings increased precipitation chances across the forecast area Thursday and Friday, with a few rumbles of thunder possible as the cold front pushes through on Friday. Additionally, high temperatures in the 60s to low 80s cool to the 40s and 50s on Saturday as noticeably colder air moves in. Behind the front, temperatures plummet into the 30s for most Saturday night with only the metro areas staying in the low 40s. Temperatures will gradually warm on Sunday with highs in the 50s to low 60s and overnight lows in the upper 30s to 40s.

Behind the frontal system, surface high pressure builds over the central CONUS beginning on Friday before shifting eastward. A tight pressure gradient between the surface high and the departing low pressure system leads to windy conditions across the forecast area Friday night into Saturday. Northwest winds gust 20 to 30 miles per hour , with higher elevations gusting up to 40 mph. Wind headlines may be needed across the higher elevations but we will continue to monitor.

It's also worth mentioning that with gusty northwest winds, upslope snow showers are possible along the Alleghenies late Friday night into Saturday morning. While snow showers are unlikely, a rain/snow mix cannot be ruled out. Little to no accumulation is expected although the first flakes of the season are possible.

AVIATION /14Z TUESDAY THROUGH SATURDAY/

VFR conditions expected for the remainder of today through Wednesday afternoon as weak high pressure resides nearby. A front will drop into the area from the north Wednesday afternoon and evening bringing spotty to scattered showers and thunderstorms. This will lead to brief sub-VFR reductions between 20-03z/4-11pm in thunderstorm activity is low over the corridor with high thunderstorm probabilities of 25 percent or greater mainly west of MRB. The front drops south of the region Thursday before stalling in the vicinity of southeast and southwest VA. This will put us in more of a wedge like pattern with on and off showers and widespread sub- VFR conditions at most of the terminals. Winds will remain out of the south today at 5 to 10 kts with occasional gusts up to 20 kts. South winds continue tonight into Wednesday at less than 10 kts. Winds will switch to the north and northeast Thursday at less than 15 kts in the wake of the frontal boundary.

On Friday, sub-VFR conditions are possible across all terminals as a cold front moves across the forecast area, bringing precipitation.
Additionally, south winds in the morning shift to northwesterly by the evening gusting 20 to 30 knots. VFR conditions are expected on Saturday with northwest winds continuing to gust 20 to 30 knots.

MARINE
South winds around 10-15 knots are expected today across the waters.
Southerly channeling effects could bring gusts close to SCA levels (around 20 knots), but this likely won't be for a long enough period to require a Small Craft Advisory. Instead, Marine Weather Statements are more likely to be issued for small crafts to exercise caution.

Winds diminish tonight into Wednesday, with generally sub-SCA conditions. A front moves south across the waters Thursday morning, and this is likely to bring SCA conditions with gusts around 20 knots for several hours. Winds do quickly diminish Thursday afternoon.

Southerly winds on Friday morning shift to northwest Friday afternoon and remain out of the northwest on Saturday. A strong pressure gradient between high pressure to the west and low pressure to the NE will bring gusty winds both days, with SCA conditions expected. Gale force winds are possible over the open waters each day.

TIDES/COASTAL FLOODING
South winds on Wednesday could result in elevated water levels at sensitive locations along the Chesapeake Bay. This could result in several stations reaching Action Stage, with Annapolis forecast to be closer to minor tidal flooding during the Wednesday evening high tide. A surge of offshore (north) winds Thursday morning will bring water levels back down.

LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.