Eastern Bay, MD Marine Forecast
|Rest Of This Afternoon...Nw Winds 5 Kt. Waves Less Than 1 Ft. Scattered Showers And Tstms.|
|Tonight...Se Winds 5 Kt. Waves Flat. Numerous Showers And Tstms. Vsby 1 Nm Or Less.|
|Thu...E Winds 5 Kt. Waves Less Than 1 Ft. A Chance Of Showers And Tstms.|
|Thu Night...Ne Winds 5 Kt. Waves Less Than 1 Ft. A Chance Of Showers And Tstms.|
|Fri...E Winds 5 Kt. Waves Less Than 1 Ft. Numerous Showers With A Chance Of Tstms.|
|Fri Night...E Winds 5 Kt. Waves Less Than 1 Ft. Scattered Showers And Tstms.|
|Sat...Ne Winds 5 To 10 Kt. Waves 1 Ft. A Chance Of Showers.|
|Sun...E Winds 5 To 10 Kt...Becoming Se After Midnight. Waves 1 Ft. Winds And Waves Higher And Visibilities Lower In And Near Tstms.|
| Area Forecast Discussion|
National Weather Service Baltimore MD/Washington DC
322pm EDT Wednesday July 6 2022
A cold front will meander over the Mid-Atlantic for the rest of the week before a second stronger cold front chases it away Saturday. High pressure will likely return Sunday into early next week.
Near Term - Through Tonight
The surface based cold front will continue to move south into the region. Satellite imagery shows a deck of broken mid-level clouds across the region with more breaks in sun to the far southwest from Highland County towards Charlottesville. Upstream of this area, showers and thunderstorms continue to rapidly develop across West Virginia with a storm motion into our southwest counties. With profiles continuing to moisten, additional showers and thunderstorms are expected to develop across this area and become concentrated and perhaps train through the evening. Therefore, have expanded the flood watch for the potential for flash flooding across this area. For the rest of the FA, as daytime heating is maximized and another shortwave progresses through amidst the northwest flow this afternoon, convection will increase in coverage.
Uncertainty arises headed into this evening with regard to shower and thunderstorm coverage. With the surface boundary sagging south across the FA, guidance signals at enhanced convergence along the boundary somewhere in the vicinity of the Mason-Dixon line towards central Virginia. PWs will approach or exceed 2" with easterly flow developing along the low levels of the atmosphere. Storm motions are rather slow and forecast to parallel the frontal boundary. This could result in an enhanced training component until the cold pool(a region of relatively cold air) becomes dominant. An additional component is the upper-level jet moving through with the right entrance region passing through leading to increased diffluence aloft. Timing for this is shortly after sunset. Given the overall setup, the flood watch for the potential for flash flooding has been expanded into parts of the eastern panhandle of West Virginia, central and northeast MD, and much of the Baltimore/Washington Metro areas. This area has the best overlap with lowered FFG to warrant a Flood Watch for the potential for flash flooding where the best low FFG/high Quantitative Precipitation Forecast signals overlap. FFG is notably higher south of I-66 in Virginia. Will continue to monitor latest mesoscale trends through this evening, but the hydro threat likely persists through much of the overnight given efficient warm rain processes and low-topped convection is able to sustain itself.
Given the CAPE/modest shear space present, any storms that do form may have a conditional severe risk (mainly wind, but some hail or a brief spin up can't be ruled out, though low-level shear is notably less today than yesterday).
Temperatures remain near seasonal levels through tonight with lows in the 70s outside the higher terrain.
Short Term - Thursday Through Friday Night
The aforementioned frontal boundary will continue moving southward on Thursday. The front will start to weaken, with the moisture remaining in place even behind the front, though columns are slightly drier than Wednesday. Overall flow remains weak, though the potential for an isolated severe storm is certainly possible Thursday into Friday. Attention will be focused upstream to the northwest for any MCS development that could track into the local region given sustainable instability.
The other concern is flooding due to repeated rounds of showers and thunderstorms through the end of the weak. Individual model guidance continues to differ significantly, though the overall signal for periods of potentially heavy rain certainly exist. Will continue to monitor.
Long Term - Saturday Through Tuesday
Unsettled conditions continue into Saturday for at least the southern half of the area as the shortwave continues to push the front southward. This will bring a few showers and storms to areas south of I-66 during the afternoon hours.
High pressure then sets up over the northeast on Saturday night into Sunday. This will bring an onshore flow into the region with below normal temperatures and slight chances for a few showers and some drizzle, along with abundant clouds, especially south of the (-66 corridor again.
High pressure pushes offshore into Monday and 500mb heigheights begin to rise as a brief upper ridge builds overhead leading to quiet weather. High temperatures remain below seasonal averages.
The next cold front will push through towards the middle of the week, perhaps on Tuesday, bringing the next chance for unsettled weather. That pattern looks to continue for several days thereafter.
Generally light W/NW flow is expected through the evening, becoming variable tonight and somewhat erratic through the end of the week as a front lingers overhead. Gusty winds, frequent light, heavy rain and perhaps a waterspout are possible with and thunderstorms - the likelihood of which will linger much of the rest of the week.
A few thunderstorms may be possible across the lower portions of the Potomac River and Chesapeake Bay on Saturday afternoon as a cold front lingers nearby. Cannot completely rule out the possibility of an SMW being issued.
Aside from that, high pressure builds in behind the showers and storms Saturday night. SCA's (Small Craft Advisories) may be needed for the open waters for the later part of the weekend, but otherwise fairly calm conditions for the long term period for the waters.e waters.
A cold front will sag slowly southward into the Mid-Atlantic through tonight. Aloft, a strong and somewhat drawn out shortwave will move along the front in W/NW flow. Although the exact placement of the front and heaviest rainfall is still somewhat uncertain, some enhanced convergence along with PWs rising above 2" should overlap areas with lower FFG resulting in a risk for flash flooding. Additionally, storm motions may be slowed some due to weakening low-level flow, and may train roughly parallel to the surface front.
The most likely time period for flash flooding is this evening into the overnight, but thunderstorms producing heavy rain will develop through the remainder of the afternoon as heating commences, and could linger well into the night given forcing from a passing upper jet streak.
NOAA Baltimore MD/Washington DC Office: Watches - Warnings - Advisories
DC...Flood Watch through late tonight for DCZ001. MD...Flood Watch through late tonight for MDZ003>006-008-011-013- 014-503>508. VA...Flood Watch through late tonight for VAZ052>054-505-506. WV...Flood Watch through late tonight for WVZ051>053.
Flood Watch through late tonight for ANZ535.