Marine Weather and Tide Forecast for Upper Marlboro, MD

NEAR TERM /THROUGH TONIGHT/
A moisture starved cold front will pass through the region this afternoon. Only real tangible wx from passing will be a reinforcement of NW winds of 20-25 mph. Breezy and warm conditions are expected behind the front as highs reach the low to mid 70s this afternoon, which is ~5 or so degrees above mid- October norms. Winds should decrease this evening.

Notably cooler tonight with lows in the 40s for most, with lower to mid 30s in the Alleghenies. Areas of frost are possible in the elevated sheltered valleys, but there appears to be enough wind through the night to prevent widespread frost from developing. Areas that do see frost likely already saw it this fall. Opted to not issue a Frost Advisory at this time given current wind forecast.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/
A rather large area of Canadian High Pressure will dominate the wx across the NE US to end the week. Dry and much cooler conditions are expected, with highs in the 60s each day.
Elevated winds remain on Thu as winds gust around 20 mph in the afternoon, then light winds for Fri as the high settles overhead.

Thu night is still expected to be the coldest night of the week when lows drop to the 30s across most of the area, except in the low 40s east of I-95. Typical sheltered high elevation valleys likely make a run into the 20s, and would not be surprised if parts of the Shenandoah Valley fall into the 20s as well with the high overhead, calm winds, and Tds in the upper 20s. Widespread frost and/or freezing temperatures looks likely along and west of the Blue Ridge. Have issued a Freeze Watch for locales west of the Blue Ridge. Frost concerns spread eastward towards the I-95 corridor. Frost Advisories are likely needed further east in future shifts.

LONG TERM /SATURDAY THROUGH WEDNESDAY/
Warmer temps return this weekend along with the chance of showers and t-storms. Most locations should see dry conditions through Sun morning due to the influence of broad high pressure departing off the Carolinas. A potent upper level trough and strong cold front look to cross the area late Sun into Mon with high pressure set to return by the middle of next week.

Sat appears to be the best of the two weekend days as high pressure drifts off the VA/NC coast. This will allow for S to Sw'ly return flow across the region boosting temps into the low to mid 70s for most. Upper 60s in NE MD.

High pressure will continue offshore late Sat night into Sun morning. Meanwhile, a cutoff area of low pressure will work from the upper Midwest toward the eastern Great lakes with a digging trough working south and east across the Ohio/Tennessee Valleys. A potent cold front will accompany the trough as the cutoff low ejects north and east into the eastern Great Lakes region. This front looks to cross the area sometime late Sun into early Mon bringing the next chance of measurable rainfall.
Continued uncertainty remains in regards to the placement/tilt of the trough and timing of the front as it swings through.
Timing may have slowed down to more of a Sun evening/night passage.

With that said, the risk for t-storms may not be out of the question including the potential for severe weather. Of course this will revolve around the timing of the front and how much instability can be maximized. Basically, a high shear to low/no CAPE environment. If the ingredients can be maximized we could be looking a a few stronger storms or at least a broken line of gusty showers pushing through the region. CIPS/CSU guidance highlights this threat, and SPC has an honorable mention in their extended outlook. This will be something that we closely monitor in the coming days ahead.

Shower activity could linger into Mon in northwest flow as the front works east at the resultant closed low departs for eastern Canada. Skies will gradually clear Mon afternoon with breezy conditions expected as the front departs east and high pressure returns from the southeast U.S. High pressure will return Tue into Wed with temps set to warm back to normal or just above normal.

AVIATION /15Z WEDNESDAY THROUGH SUNDAY/
VFR conditions are expected to prevail for the rest of this week.
Gusty N to NW winds expected today and Thu, from late morning to late afternoon, with gusts around 20-25 knots. Light winds Fri as the high settles overhead.

VFR conditions are expected across the terminals through Sun morning. Sub-VFR conditions return with a potent cold front Sun afternoon into the night. Showers and perhaps a few t-storms look to accompany this front as it pushes through. VFR conditions return Mon and Tue next week.

MARINE
A cold front will move through the region today, then Canadian high pressure builds in through the end of the week. A surge of northerly winds behind the front tonight will bring gusts up to 25-30 knots over the open waters of the Chesapeake Bay. After that, gusts will mainly be between 20-25 knots across the waters through Fri morning. Fri during the day there remains some uncertainty with the strength of the gradient and inherent winds. Southern waters likely need extended at least partially into the day Fri, though uncertainness remain with northward extent of SCA gusts. Will let future shifts evaluate. Winds diminish below SCA levels by Fri evening.

No marine hazards are expected Sat through Sun morning. Sub-SCA S'ly winds will remain between 10 to 15 kts. SCA southerly channeling returns ahead of the front Sun with gusty west to northwest SCA level flow behind the front Sun night into Mon next week.

FIRE WEATHER
Elevated fire weather conditions are possible Thu afternoon due to the combination of gusty winds and low RH values. NW winds could gust around 20 to 25 mph along and north of Route 50, with gusts of 15 to 20 mph to the S. Minimum RH values are forecast to be 25-35%, with the driest in the central Shenandoah Valley.
Based on available data, fuels appear a tad above thresholds as well in terms of moisture.

LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...Small Craft Advisory until 6 AM EDT Friday for MDZ008.
Freeze Watch from late Thursday night through Friday morning for MDZ003-501-502-509-510.
VA...Freeze Watch from late Thursday night through Friday morning for VAZ025>031-503-504.
WV...Freeze Watch from late Thursday night through Friday morning for WVZ050>053-055-501>506.
MARINE...Small Craft Advisory until 6 AM EDT Friday for ANZ530>534- 537>543.
Small Craft Advisory until 8 PM EDT this evening for ANZ535- 536.
Small Craft Advisory from 10 AM to 8 PM EDT Thursday for ANZ535-536.