Marine Weather and Tide Forecast for Annapolis, MD

NEAR TERM /THROUGH TONIGHT/
The CAD wedge continues to remain over the region today with strong inversion this morning. This has led to a continuation of low clouds, fog, drizzle, and passing showers across much of the region.

A pronounced area of stratiform rain has developed from the DC Metro north to Baltimore and northern MD. This does not look likely to dissipate until this afternoon, so adjusted the rain chances as the NBM proved too low. Elsewhere, some light showers are ongoing, but coverage is much lower south of I-66 and west of the Blue Ridge.

Meanwhile, another ripple of shortwave energy is spinning back across southern Ohio, western WV, and eastern KY. This feature along with the dissipating stalled front to the south will be the catalyst once again for showers and perhaps a few thunderstorms across portions of the region later this afternoon and into the evening hours. Highest coverage for shower and thunderstorm activity today looks to be once again across the Alleghenies back into southwest and south-central VA.

A Flood Watch remains in effect for the Alleghenies from noon through midnight tonight. These locations received anywhere between 0.50-2" of rain yesterday that will further aid in flooding concerns today.

Convective development once again appears to be midday through roughly 7-9pm this evening. MUCAPE values will hover between 500-800 j/kg with 0-6km shear values around 30 kts. PWATS will remain elevated between 1.5 and 2.0 inches. Efficient warm rain processes will once again result in quick rainfall accumulations in a short period of time.

Cloud cover prevails, limiting highs temperatures to the upper 60s and low 70s areawide. Locations west of the Allegheny Front and south of I-64 may filter a break of sunshine or two yielding highs in the mid to upper 70s.

The wedge remains in place as flow in and above the boundary layer is not strong enough to scour it away. This means more of the same with low clouds, fog, drizzle, and lingering showers at times tonight. Lows fall back into the low to mid 60s.
Values closer to 70 degrees can be found in the Baltimore/DC urban centers, near the bay, and south of the I-64 corridor.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/
The stalled surface boundary that will have lingered over the area for several days will finally start to dissipate and lift north of the area as a warm front Tuesday into Wednesday. Meanwhile, a subtle upper level trough will approach from the Ohio Valley. Showers and thunderstorms are expected to form during the afternoon hours within a very humid airmass (surface dewpoints around 70). The risk for severe weather is low, but not 0 with the Storm Prediction Center highlighting a Marginal Risk (Level 1 out 5) over portions of the Alleghenies and Shenandoah Valley/central Piedmont region. Damaging winds look to be the main threat with storms along with localized flash flooding. Storms should be fairly progressive, but given the antecedent conditions and moist atmosphere at play localized instances of flash flooding cannot be ruled out. CAPE values will approach 2000 j/kg with 0-6 km shear values 35 to 45 kts. High temperatures on Tuesday are expected to be reach into the upper 70s and lower to mid 80s for most as sunshine returns. Lows Tuesday night will fall back into the upper 60s and low 70s. FOg will be possible during the overnight hours given the very moist airmass overhead.

More of the same can be expected Wednesday as the warm front lifts further north of the area. This will allow hotter temperatures to move in along with slightly drier conditions under the influence of west to southwest downsloping flow. Current CAMS and synoptic guidance still hint on the threat of a few showers and thunderstorms during the afternoon and evening hours Wednesday. This is due largely in part to a shortwave trough ejecting east of the Ohio River Valley. Highest probability of severe thunderstorms looks to be west of the Alleghenies where the shortwave trough will reside.
Elsewhere, pop showers and thunderstorms are likely given the hot and humid airmass in place. Highs Wednesday will push into the mid to upper 80s and low 90s outside the mountains.

The lead shortwave trough works east Wednesday night into THursday as the cold front approaches form the Ohio River Valley. Convection over the mountains will work east as well before slowly dissipating given the lack of instability during the overnight hours. Lows Wednesday night will fall back into the low to mid 70s.

LONG TERM /THURSDAY THROUGH SUNDAY/
High pressure strengthens offshore moving into the middle of the week, leading to south to southwesterly low-level flow and increasing heat and humidity locally. Temperatures should reach into the 90s on both Wednesday and Thursday. When combined with dewpoints in the lower 70s, heat indices may approach 100 on Thursday.
Thunderstorms could have decent coverage on Thursday as an upper trough tracks off to our north across the Great Lakes, with its associated cold front approaching from the west. Current model guidance suggests that ample instability and shear may be present on Thursday, so some storms may be on the stronger side. SPC has the area highlighted with a D4 outlook, so definitely something to keep an eye on.

Upper troughing is expected to dig in from the Great Lakes on Friday. Cooler and drier conditions are expected locally in the wake of the system's cold front Friday into Saturday before warming up on Sunday.

AVIATION /14Z MONDAY THROUGH FRIDAY/
IFR conditions look to continue through mid-morning as a result of low clouds, passing showers, and patchy drizzle. An area of broad light rain will continue through early afternoon at IAD, DCA, BWI, and MTN. OVC CIGS will continue to hover between 500-1000 feet, with pockets of sub 500 feet CIGS amongst the terminals through at least 15z/11am this morning.

CIGS may lift a bit this afternoon and evening as additional shower activity works through. The highest concentration of showers and perhaps a few thunderstorms this afternoon to remain west of KMRB and KCHO. Shower activity may filter back into the I-95 corridor late in the afternoon and through the evening hours. PROB30 groups have been introduced to highlight this.

Low clouds, fog, and drizzle set up again overnight leading to additional IFR CIGS/vsbys and even some brief periods of LIFR west of the corridor terminals.

Conditions are expected to improve late Tuesday morning into Tuesday afternoon as warm front lifts through the area. This will finally scour out the low clouds. Temporary drops to sub- VFR conditions may be possible in thunderstorms both Tuesday and Wednesday afternoon, especially at terminals along and west of the Blue Ridge.

Prevailing VFR conditions are expected Thursday. Temporary drops to sub-VFR conditions may be possible in thunderstorms especially Thursday afternoon and evening.

MARINE
A stalled front will remain south of the waters through this evening. Easterly winds around 10 knots, and likely remain sub-SCA through the start of the week. Occasional gusts to around 20 knots are possible at times. Low clouds and some marine fog is possible this morning and again tonight given the moist airmass in place. A warm front will lift back across the waters Tuesday into Wednesday.

Sub-SCA level southerly winds are expected over the waters on both Tuesday and Wednesday. An SMW or two cannot be ruled out with scattered showers and thunderstorms during the afternoon and evening hours.

SMWs are possible given thermodynamic and kinematic environment for Thursday in any thunderstorm. SCA conditions likely return with cold frontal passage Thursday into Friday.

LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...Flood Watch through this evening for MDZ501-509-510.
VA...Flood Watch through this evening for VAZ503-504.
WV...Flood Watch through this evening for WVZ501>503-505-506.
MARINE...None.