Area Forecast Discussion

WHAT HAS CHANGED

Coastal Flood Advisory has been issued for Anne Arundel County.

KEY MESSAGES

- 1) Showers and possible thunderstorms return Sunday.

- 2) Rain showers & cooler temperatures persist into midweek ahead of drier conditions next weekend.

DISCUSSION

KEY MESSAGE 1...Showers and possible thunderstorms return Sunday.

Fair weather is expected through this evening. Low overcast conditions are expected to develop late this evening and through the overnight as moisture advection develops atop a shallow cool layer on SE winds. By daybreak, expect showers to move into western Maryland and track southeast across the area. A second round of afternoon showers is expected to move in from the Appalachian region and southern Pennsylvania. A few thunderstorms are possible along Interstate 64 in central Virginia, but severe wx appears unlikely. Showers will continue into the evening along a frontal zone before dissipating or shifting south late Sunday night.

Light rain or off and on showers will persist through Tue morning, particularly along and west of the Blue Ridge Mountains in areas of onshore flow. Expect a noticeable cooling trend beginning Monday in the wake of the cold front late Sunday night.

KEY MESSAGE 2...Rain showers & cooler temperatures persist into midweek ahead of drier conditions next weekend.

Mid-level moisture overhead will coincide with an area of low pressure just off the East Coast tracking north on Wednesday. Weak instability at the surface will suppress thunderstorm activity for the most part, but expect rain showers to continue through Wednesday and Thursday as shortwave disturbances continue to track across tShowers and possible thunderstorms return Sunday.he Mid- Atlantic. High temperatures continue to range in the 60s as these disturbances move through.

As the coastal low skirts the Mid-Atlantic coastline, winds will be elevated Wednesday and Thursday with wind gusts between 20-30 MPH possible, especially along the Chesapeake Bay. Winds could potentially be higher over the waters, and this onshore flow combined with stronger tidal influence could increase coastal flood risk during this period. Refer to the coastal flooding section below for more details.

As this system tracks north towards the end of the week, winds along the coastline should gradually decrease. Mid-level dry air moves in overhead from the Midwest, which should lead to diminishing rainfall potential heading into the weekend.

AVIATION /19Z SATURDAY THROUGH THURSDAY/

Low overcast conditions/MVFR cigs are expected to develop late this evening and continue through midday Sunday. Sunday will feature two rounds of showers, one in the morning, and one in the afternoon toward evening. Any thunderstorms would be confined to KCHO. Monday and Tuesday will feature low overcast conditions with flight restrictions likely.

Intermittent sub-VFR conditions could persist into Wednesday & Thursday as scattered showers continue throughout the region. Gusty winds between 20-25 knots are possible on Thursday. Winds flow from northeasterly to northerly by Friday.

MARINE

Winds will flirt with SCA across the Chesapeake Bay waters through Monday night. A more definite upward trend is seen starting late Monday night through the middle of the week when additional advisories will be needed.

North to northeasterly Wind gusts remain elevated through Wednesday and Thursday as an area of low pressure remains off the East Coast. Showers & a couple of thunderstorms are possible over the waters during this period. As this system begins to track north late in the week, winds should begin to decrease heading into the weekend.

TIDES/COASTAL FLOODING

Coastal Flood Advisory has been issued for Anne Arundel County. CBOFS guidance seems like the only guidance performing well with the elevated water levels and showing the rapid response due to the onshore flow.

Onshore flow will persist through at least the middle of next week with water levels remaining elevated with minor coastal flooding expected at times of high tide. At this time, the risk of moderate coastal flooding seems low.

LWX WATCHES / WARNINGS / ADVISORIES

DC...None. MD...Coastal Flood Advisory from 9 PM this evening to 5 AM EDT Sunday for MDZ014. VA...None. WV...None. MARINE...Small Craft Advisory until 1 AM EDT Sunday for ANZ534-537-543.