Marine Weather and Tide Forecast for Mayo, MD

NEAR TERM /THROUGH TONIGHT/
Ongoing showers across the area as of 300 am will continue to move off to the northeast over the next couple hours. Nothing heavy by any means, more so light wetting rains. Attention then turns to a decaying MCS across West Virginia and southwest Virginia. This will bring rain to the area in the predawn and near the metros by daybreak into the morning rush. Expecting some embedded pockets of more moderate intensity rain unfold as mesoscale impulses aloft track though from a larger scale trough.

Flood Watches remain in effect across far western Maryland (Garrett and Allegany), while extending down into Mineral and western Grant counties. These continue through late tonight.
This area is of greatest concern for hydrologic issues given the excessive rains of last week. WPC has maintained a Slight Risk for excessive rainfall in this area where the stationary front looks to stall with easterly flow east of the front running into westerly flow west of the front. Additionally, also given past history over the northern Blue Ridge Mountains and adjacent easterly upslope counties, a Flood Watch is in effect for this area until 11 PM tonight. However, the signal is much stronger for heavier rainfall across the former watch area where 2 to 3 inches of rain are possible.

A more defined upper low/trough which is set to track from the Ohio Valley toward the Mid-Atlantic on this afternoon/evening.
Increasing lift with this trough coupled with anomalous moisture and local orographic should all play a role in locally heavier rainfall in the northwest tier of the flood watch.

For the rest of the forecast area, a soaking rain overspreads the region which will hopefully alleviate the ongoing drought issues. With strong high pressure to the north and a wavy frontal zone over the Carolinas, the region remains wedged in within a CAD setup. As a result, a very stable profile sets up which should mitigate overall thunderstorm chances. As expected, SPC has removed the Marginal Risk of severe weather from the forecast area due to the CAD signature and no real instability making it into the area. Will have to keep an eye west of the Allegheny Front in case anything gets going to the west of the mountains.

Well below average temps today with highs in the upper 50s to 60s (slightly cooler in the mountains). This comes with thick low clouds and east-southeasterly gusts up to 20 to 25 mph, especially east of the Blue Ridge and Catoctins. Rain continues off and on into the overnight hours which will favor a low diurnal temperature range. For tonight, expect lows in the mid/upper 40s in the mountains to 50s elsewhere. As mentioned, there may be some breaks in the action as focus shifts toward a developing wave of low pressure near the Virginia Tidewater region. This would support some dry slot over the area as the energy transfer unfolds.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/
As the upstream upper low wobbles eastward, the associated embedded shortwaves will pass overhead on Thu. Additional rain showers or even a period of steadier rain is possible as a lobe of vorticity rotates through the area. Better forcing is north into PA, but regardless more rain is likely across the area. The biggest difference between the two days will be much less moisture availability as precipitable water values drop to below an inch. As a result, total rainfall amounts should be lower, generally averaging between 0.20 to 0.40 inches. The atmosphere should be more unstable as the CAD wedge will have eroded. Thus, expect isolated thunderstorms to pop up during Thu afternoon to evening, especially in areas that can see some sunshine.
Forecast highs will mainly be in the 60s, but expect 50s in the mountains and low/mid 70s along and east of I-95. This also comes with a shift in winds given low pressure to the east.
Mainly west to northwesterly winds are expected with gusts up to 20 to 25 mph, locally up to 35 mph along the Allegheny ridges.

Conditions gradually dry out through the night with even some breaks in the cloud cover. Forecast lows drop into the mid 40s to mid 50s.

Given the position of the ULL Fri, a continued cool NW flow will continue into the area. The majority of the day Fri is expected to stay dry, but an uptick in both cloud cover and areal coverage of showers will occur during the afternoon in response to daytime heating and resultant destabilization. Below normal temperatures (highs in the 60s, lows in the 40s to low 50s) on Fri.

LONG TERM /SATURDAY THROUGH TUESDAY/
Low pressure will continue to reside near New England into Saturday while high pressure builds in from the northwest. However, there may still be enough moisture in northwest flow for a stray shower or sprinkle, mainly closer to the Pennsylvania border. Northwest winds will remain gusty. The low will pull away Sunday, but the high will never fully move into the region, as an upper trough in the Plains causes a warm front to start lifting north toward the area. The frontal zone will be nearly parallel to westerly flow aloft stretching from the mid Mississippi Valley toward the Mid Atlantic.
This will provide the opportunity for upper level ripples to combine with moisture overrunning the frontal zone to produce showers as early as Sunday. An upper level low may eventually form early next week as a surface low moves toward the area. This would likely draw additional moisture into the area (and the highest rain chances of the stretch) Monday into Tuesday. The low may not clear the area until the middle of next week. It's too early to speculate on rainfall amounts with lots of model spread at this point in how the system will evolve.

While temperatures may tick up slightly by Monday and Tuesday, overall below normal temperatures will continue through the long term period. Highs will be in the 60s to lower 70s with lows in the 40s and 50s.

AVIATION /07Z WEDNESDAY THROUGH SUNDAY/
Ceilings are expected to drop through MVFR to IFR by daybreak and may remain that way throughout Wednesday. Models continue to hint at a break of rain during the middle of the day/early afternoon which may allow conditions to improve to MVFR. At times, visibility could also begin to near IFR within the moderate to heavy downpours. This also comes with increase east- southeasterly winds which will begin gusting to around 20 knots by late Wednesday morning. These winds also make sustained IFR conditions uncertain, especially the further east towards DCA and BWI. Anywho, such wind fields persist through the afternoon to early evening hours. Another wave of moderate rain will likely arrive toward this evening. Restrictions hold in place for all terminals into tonight, some potentially falling to LIFR at times.

As low pressure forms to the east near the Virginia coastline, winds shift over to west-northwesterly on Thu. Additional restrictions are possible as well as more showers pass through the area. However, do expect more breaks in the action, but with isolated thunderstorms possible during Thu afternoon to evening. Continued west-northwesterly winds should gradually dry things out into Thu night. Depending on how much low-level moisture is left, some return to VFR conditions is possible.

VFR conditions will prevail Fri into Sat with northwesterly wind gusts up to 20-25 kt. Showers and sub-VFR conditions could move back into the area as early as Sunday ahead of a warm front, but confidence is currently low.

MARINE
East-southeast winds will steadily increase through daybreak.
All waters should have gusts of 20-25 kt today. There is a low chance of a few gusts near gale force on the middle bay, but uncertainties wrt the inversion and how much wind punches through exist. Winds will decrease tonight as low pressure moves up the coast, with advisories ending.

As low pressure passes by to the east, winds shift to mainly west-northwesterly on Thu. These come with continued shower chances, but as not continuous and concentrated as Wednesday.
Isolated thunderstorms cannot be ruled out during the afternoon/evening hours. Outside of any such storm, winds should stay below advisory levels.

Small Craft Advisory conditions remain possible Fri into Sat in continued northwest flow. Low pressure to the northeast finally pulls away Sunday, so winds are expected to be lighter.

TIDES/COASTAL FLOODING
The combination of strong high pressure to the north over Ontario with low pressure passing through to the south will shift winds to easterly while strengthening in time today.
Through Thu morning, there will be an increasing threat for Minor tidal flooding at the more sensitive locations. Have issued a Coastal Flood Advisory for Annapolis for the next two high tides. If anomalies continue to spike, there is a low end chance for moderate tidal flooding. Water levels eventually drop off on Thu as winds shift to northwesterly.

LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...Small Craft Advisory from 6 AM this morning to midnight EDT tonight for MDZ008.
Coastal Flood Advisory from 11 AM this morning to 5 AM EDT Thursday for MDZ014.
Flood Watch through late tonight for MDZ501-502-509-510.
VA...Flood Watch through this evening for VAZ038>040-507.
WV...Flood Watch through late tonight for WVZ501-503-504.
MARINE...Small Craft Advisory from 6 AM this morning to midnight EDT tonight for ANZ530-531-535-536-538-539-542.
Small Craft Advisory until midnight EDT tonight for ANZ532>534- 537-540-541-543.