Marine Weather and Tide Forecast for Highland Beach, MD

KEY MESSAGES
- 1) Near-record warmth Monday through Wednesday, with isolated storms possible over the mountains Monday and Tuesday.

- 2) A strong cold front moves through on Wednesday, bringing chances for thunderstorms. Much cooler and showery conditions are expected to end the week.

DISCUSSION
KEY MESSAGE 1...Near-record warmth Monday through Wednesday, with isolated storms possible over the mountains Monday and Tuesday.

Conditions remain dry and mild across the area this evening. It will be another warm night tonight, with just a few passing high clouds. Patchy fog may also be possible late tonight, especially to the west of the Blue Ridge. Low temperatures are forecast to be in the 60s.

Tomorrow looks like it will be the hottest day of the year thus far, with temperatures forecast to climb into the mid 90s across the lower elevations (80s in the mountains). As upper level ridging strengthens overhead, most locations should stay dry with mostly sunny skies. The exception will be far northwestern portions of the forecast area (the WV Panhandle and Western Maryland), where many forecast models show thunderstorms forming during the late afternoon and evening hours. If storms do form, many of the ingredients are there for storms to produce gusty winds. Forecast soundings show steep low-level lapse rates, inverted V soundings with ample dry air below the cloud base, MLCAPE values of 1000-2000 J/kg, DCAPE values of 1000-1300 J/kg, and enough mid-level flow (20-30 kt) to provide some organization to any cold pools that develop. Some CAMs show gusts of near or over 50 knots with these storms as they track from southwest to northeast, and nearly all CAMs shows gusts in excess of 40 knots. As a result, the potential for severe storms tomorrow across the West Virginia Panhandle and Western Maryland bears watching. Any storms should wind down through the evening hours, with dry conditions expected for much of tomorrow night. Hot conditions are expected again on Tuesday, but the upper ridge will continue to strengthen aloft, making conditions even less favorable for the development of storms. However, an isolated storm or two can't be completely ruled out over the higher terrain.

Outside of the afternoon/evening shower and thunderstorm threat will be the bigger story which is the heat. This will become really pronounced by Monday and continue through Wednesday, with widespread highs in the low to mid 90s each day. Tuesday will mark the hottest day of the next 7 with highs in the mid to upper 90s east of the mountains. Wednesday will then be slightly cooler compared to Tuesday, but still well into the 90s for most. The humidity will gradually increase each day, though not to the extent where heat headlines will be needed. Something that we'll continue to monitor since we are early in the season. Don't expect too much relief from the heat at night with low temperatures Monday and Tuesday nights in the mid 60s and low 70s.

KEY MESSAGE 2...A strong cold front moves through on Wednesday, bringing chances for thunderstorms. Much cooler and showery conditions are expected to end the week.

A mid-week frontal system remains on track to impact the area, albeit with some uncertainties in the overall details. Most notably, the core of the forcing and stronger wind fields with this trough look to be well north of the region. Both of those components will lend itself to a less organized convective event. However, the timing of the cold front does align closely to the peak in diurnal heating. Given multiple days of well above average temperatures, this system will be conducive to shower and thunderstorm development. This should especially be the case along the developing lee trough and trailing cold front. The severe weather aspect remains the biggest question mark at this time.

Any convective chances likely wind down on Wednesday night as the cold front eventually settles near the Virginia Tidewater region on Thursday morning. This supports a shift to northerly winds on Thursday which is accompanied by a rather dramatic cool down.
Forecast highs are likely to not escape the upper 60s to low 70s which is around 15 to 25 degrees lower than previous days. Expect a similar temperature forecast for Friday as well with the shift to an onshore easterly wind. A gradual warm up is possible next weekend, but this will depend on the degree of cloud cover and extent of rainfall.

This overall pattern remains quite stagnant as the earlier frontal zone stalls near the southeastern U.S. Meanwhile, strong high pressure settles across eastern Canada down into New England. Within the southwesterly flow aloft, a series of mid/upper disturbances will keep daily chances for rain in the forecast. The setup looks more convectively-stable in nature which would limit thunderstorm chances for this late week period.

AVIATION /00Z MONDAY THROUGH FRIDAY/
Prevailing VFR conditions are expected across the terminals through Tuesday as high pressure strengthens offshore.
South/southwesterly winds return Monday and Tuesday gusting between 15 to 20 kts during the afternoon and evening hours.
Daily shower and thunderstorm chances will occur each afternoon although coverage will be spotty in nature between the terminals. The highest confidence for showers and t-storms appears to be west of MRB, HGR, and FDK. where brief reductions are possible. Elsewhere confidence remains low given the lack of a lifting mechanism.

Some restrictions are possible on Wednesday, particularly given the expectation of afternoon/evening showers and thunderstorms with the cold front. Prevailing winds will be out of the southwest through much of the day before this front passes through. Some low ceilings are possible into Wednesday night as the system presses off to the south and east. Winds shift to north to northwesterly for much of Thursday before turning more easterly by Friday. With the presence of low clouds and rain at times, sub-VFR conditions are looking possible during the Thursday through Friday timeframe.

MARINE
Sub-SCA level winds are expected through Monday morning.

South southeasterly winds return Monday with gusts up to 20 knots across the bay and lower tidal Potomac. A Small Craft Advisory was issued for Monday afternoon into Monday evening.
Additional SCAs may be needed due channeling Tuesday into Tuesday night, especially over the wider waters. Winds will continue out of the south and southwest with gusts up to 20 kts.

For Wednesday, marine winds ahead of the front should largely meander between south and southwesterly. This cold front will increase the risk of showers and thunderstorms, particularly during the afternoon/evening hours. Any of the stronger convection may require Special Marine Warnings. Overall storm chances wind down late Wednesday night as winds shift to mainly northerly on Thursday.
A frontal surge will bring gusts up to 20 knots which may require Small Craft Advisories through midday Thursday. Thereafter, winds drop below advisory thresholds.

CLIMATE
Here are some daily temperature records during the May 18-20, 2026 timeframe:

A '+' sign indicates multiple years currently hold that record.
A '!' sign indicates the record is forecast to be tied or broken.

***MONDAY, MAY 18TH, 2026*** LOCATION RECORD HIGH (YEAR) RECORD WARM LOW (YEAR)
Washington-National (DCA) 96F (1877) 72F (2015)
Washington-Dulles (IAD) 91F (1987)! 68F (2015)! Baltimore (BWI) 97F (1962) 70F (2017)
Baltimore Inner Harbor (DMH) 97F (1962) 75F (2017)
Martinsburg (MRB) 96F (1911) 66F (2015)! Charlottesville (CHO) 95F (1962)+ 73F (1911)
Annapolis (NAK) 95F (1962)+ 69F (1953)+! Hagerstown (HGR) 93F (1962) 71F (2017)

***TUESDAY, MAY 19TH, 2026*** LOCATION RECORD HIGH (YEAR) RECORD WARM LOW (YEAR)
Washington-National (DCA) 96F (1997)+ 72F (2015)! Washington-Dulles (IAD) 92F (1997)+! 66F (2017)+! Baltimore (BWI) 98F (1962) 75F (1877)
Baltimore Inner Harbor (DMH) 98F (1962) 78F (1962)
Martinsburg (MRB) 98F (1911) 69F (1996)! Charlottesville (CHO) 97F (1962) 72F (1997)
Annapolis (NAK) 96F (1962) 71F (1911)! Hagerstown (HGR) 97F (1996) 69F (2017)+!

***WEDNESDAY, MAY 20TH, 2026*** LOCATION RECORD HIGH (YEAR) RECORD WARM LOW (YEAR)
Washington-National (DCA) 96F (1996) 73F (2019)
Washington-Dulles (IAD) 93F (1996) 69F (2019)
Baltimore (BWI) 95F (1962) 71F (2019)+ Baltimore Inner Harbor (DMH) 97F (1962) 74F (1998)+ Martinsburg (MRB) 97F (1911) 70F (1998)
Charlottesville (CHO) 96F (1996) 73F (1996)
Annapolis (NAK) 98F (1997) 76F (1898)
Hagerstown (HGR) 97F (1996) 66F (1998)

LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 3 PM Monday to 2 AM EDT Tuesday for ANZ531>534-537>543.