Marine Weather and Tide Forecast for Annapolis Neck, MD

NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/
A trough located over the Great Lakes will approach the area this evening, while a weak surface low over Ohio moves eastward.
Skies remain clear across much of the area early this afternoon, but warm advection forced snow is already entering the Allegheny Mountains. This system will be moisture starved in nature, but the combination of synoptic scale ascent and upslope flow will be enough to produce snow showers through tonight in the Alleghenies, heaviest during the early evening hours along and in the wake of the cold front. Around 2-3 inches of very light, fluffy snow is expected by late tonight. Have held off on advisories for now due to the brief duration (~6 hours) for the bulk of the accumulating snow, but this will be monitored over the next several hours. Winds will also be gusty out of the west, which could lead to blowing snow at times. There's a brief window early this evening where heavier snow showers or squalls are possible. As the Froude number increases above 1, some snow showers or streamers could spill east toward the northern Shenandoah Valley. Further east, a few passing flurries can't be ruled out during the early evening (mid level warm advection)
and mid to late evening (decaying snow showers with moisture/instability in the DGZ), but conditions should remain predominantly dry. Some guidance does have spotty snow accumulation all the way to the Chesapeake Bay, but this should be the exception, not the rule.

There will be a stronger surge of winds overnight in the wake of the cold front. This will hold temperatures up (mid teens to lower 20s) but bring down wind chills. Widespread wind chills in the single digits are expected late tonight but should remain above Cold Weather Advisory criteria for much of the area, However, wind chills will reach -10 to -20 in the Alleghenies and along the Blue Ridge, where Cold Weather Advisories have already been issued.

SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/
High pressure will build to the southwest Wednesday, leading to decreased snow shower activity in the mountains, and completely dry conditions further east. However, the pressure gradient will remain tight, with blustery WNW winds gusting 20-35 mph. The cold advection will result in highs only in the mid 20s to mid 30s. Wind chills will remain the in the mid teens to mid 20s, with near to below zero in the higher elevations.

A clipper system embedded in northwesterly flow aloft will track toward the area on Thursday. This system will have slightly more moisture to work with, and should produce a period of snow showers in the mountains Thursday into Thursday night. Snow may be moderate to heavy at times with relatively high snow ratios. Current projections are for 3-6 inches of snow in the Alleghenies, but amounts have been trending higher. Flurries will once again be possible to the east of the mountains, and there is a small chance for some steadier snow showers to spread east and produce a quick coating of snow. Locations between the Alleghenies and Blue Ridge (I-81 corridor), as well as northern Maryland should have the best chance (east of the Alleghenies)
to experience steadier snow during this time. It will be yet another cold day, with mostly cloudy skies and high temperatures in the upper 20s to mid 30s at lower elevations and 20s in the mountains.

LONG TERM /FRIDAY THROUGH TUESDAY/
Synoptically, broad upper level troughing will continue to reside over the eastern half of the CONUS with ridging across the western U.S. Ensemble and deterministic guidance continues to remain persistent on upper level troughing holding firm over the eastern U.S and central U.S through the middle of next week. Embedded in the trough will be a series of shortwave disturbances and an Arctic front that looks to cross the area this weekend into the start of next week. The features of most concern look to push across the area Saturday into Saturday evening and late Sunday into early Monday.
These two time periods look to be the best windows of opportunity for increased precipitation chances across the region.

Brief high pressure builds back into the area Friday before sliding off the VA/NC coast Friday evening into Friday night. As a result, expect south to southwesterly flow to ensue Friday afternoon boosting temperatures back into the 40s for daytime highs east of the mountains. Dry conditions will continue into Friday night with increasing clouds late as high pressure pushes further offshore.
Lows Friday night will fall back into the upper 20s and low 30s.

By Saturday, we await the arrival of low pressure tracking out of the southern Plains/lower MS River Valley toward the Carolinas.
Increasing isentropic lift and warm air advection ahead of this system will allow precipitation to break out across areas west of the Blue Ridge early Saturday morning into Saturday midday.
Precipitation will then work east of the Blue Ridge and toward the metros late Saturday morning and evening before diminishing east of the mountains Saturday night. Models remain a bit disjointed with the main energy source Saturday although confidence continues to increase for some wintry precipitation especially at the onset along and west of the Blue Ridge and perhaps along the PA/MD line as antecedent cold temperatures will remain in place. Elsewhere, rain is expected as southerly flow increases in the mid-levels Saturday morning into Saturday afternoon. Mountain locations especially west of the Alleghenies could hold onto mixed precipitation through the entirety of the event. High temperatures Saturday will push into the mid to upper 40s with 30s across the high valleys of the Blue Ridge and Allegheny Front. Lows Saturday night will fall back into the mid to upper 20s and low 30s.

The cold front will work south and east of the area Sunday into Sunday night. Cold air advection will quickly race in along with lingering mountain upslope snow showers. Meanwhile, the front will reside toward the coast with a trailing low pressure system racing north and east from the Carolinas and toward the New England coast late Sunday into Monday morning. Some uncertainty remains in regards to this storm system especially when it comes to intensity (i.e forcing) and moisture advection during the aforementioned timeframe above. For now, went with a blend of ensemble and deterministic guidance leaving a chance of snow in the forecast Sunday into Sunday into Sunday night. Precipitation chances look to gradually decrease Monday into Tuesday as 1045-1050 mb Arctic high pressure builds into the region. High temperatures Sunday will top out in the mid to upper 30s and low 40s with 20s in the mountains. By Monday and Tuesday, high temperatures will struggle to get out of the 20s with 850 mb temperatures in the -16 to -21 degree C range. Low temperatures Monday and Tuesday nights will fall into the teens and single digits with wind chills following a similar trend.

AVIATION /20Z TUESDAY THROUGH SUNDAY/
VFR conditions are expected through Wednesday night, though a period of VFR ceilings are expected this evening. Some flurries may spill east of the mountains late this afternoon into the evening (most likely to affect MRB), but steadier snow is unlikely at this time. Winds will be out of the WNW through Wednesday night. A relative lull is occurring this afternoon but will increase again this evening as a cold front moves through, with a possible stronger surge of winds of 25-35 kt toward midnight. There may be a relative decrease around sunrise before 25-30 knot gusts resume through the day on Wednesday.

Winds will lessen Wednesday night then become southwesterly on Thursday. A clipper system will affect the region Thursday into Thursday night. There is a low chance of MVFR conditions and a brief period of light snow or flurries, mainly at MRB.

VFR conditions are expected Friday into Friday night with high pressure nearby. Westerly winds will switch to the south and southwest Friday afternoon and night as high pressure pushes offshore. Increasing clouds and southerly winds are expected Saturday ahead of a strong cold frontal boundary. Sub-VFR conditions look to return Saturday morning into Saturday evening as widespread precipitation chances are expected across the terminals. Additional sub-VFR conditions are expected Sunday as another wave of low pressure pushes through. Winds will remain elevated out of the northwest in the wake of the departing frontal boundary.

MARINE
Relatively lighter winds are occurring this afternoon. However, a surge of stronger winds in northwesterly flow will occur tonight behind a reinforcing cold front. Gale Warnings are in effect for all waters tonight. SCAs will likely be needed Wednesday through at least part of Wednesday night in continued northwesterly flow. Winds finally decrease to sub-SCA levels out of the southwest on Thursday, but could near low-end SCA levels over the widest waters. A clipper system pushing through Thursday night could also lead to a slight uptick in winds.

Sub-SCA level westerly winds are expected through the front half of Friday as high pressure sits nearby. Winds will turn to the south and southwest Friday afternoon and night as high pressure pushes offshore. SCA conditions will likely return to the wider waters Friday night and into Saturday due to southerly channeling.
Northwest winds are expected in the wake of the boundary Saturday night with near SCA level winds expected Sunday in post-frontal northwest flow.

TIDES/COASTAL FLOODING
Offshore flow behind a series of fronts is resulting in declining water levels. The strongest negative surge will take place tonight into Wednesday, when blowout conditions will be possible. Water levels will return closer to normal by Thursday as winds take a more southwesterly direction.

LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...Small Craft Advisory until 6 PM EST this evening for MDZ008.
Gale Warning from 6 PM this evening to 6 AM EST Wednesday for MDZ008.
Cold Weather Advisory from 6 PM this evening to noon EST Wednesday for MDZ001.
Cold Weather Advisory from 6 PM this evening to 10 AM EST Wednesday for MDZ501.
VA...Cold Weather Advisory from 6 PM this evening to noon EST Wednesday for VAZ503.
Cold Weather Advisory from 6 PM this evening to 10 AM EST Wednesday for VAZ504-507-508.
WV...Cold Weather Advisory from 6 PM this evening to noon EST Wednesday for WVZ501-505.
Cold Weather Advisory from 6 PM this evening to 10 AM EST Wednesday for WVZ503-506.
MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ530>543.
Gale Warning from 6 PM this evening to 6 AM EST Wednesday for ANZ530>543.