Marine Weather and Tide Forecast for Dundalk, MD

KEY MESSAGES
- 1) Heat, humidity, and an approaching cold front bring the next chance for severe weather on Thursday.

- 2) A warm front is spawning a couple of showers in parts of Northeast Maryland and far southern Maryland. A thunderstorm cannot be ruled out in parts of the region.

- 3) Thunderstorm potential will return late Sunday into Monday.

DISCUSSION
KEY MESSAGE 1...Heat, humidity, and an approaching cold front bring the next chance for severe weather on Thursday.

A very strong low pressure system is forecast to track northeast from the Great Lakes on Thursday with the associated cold front pushing across the forecast area through the day. Ahead of the cold front, southerly flow ushers in warm air with high temperatures in the 80s to mid 90s. Gusty winds should keep heat indices near the high temperature, although hot and humid conditions are expected.

The combination of the warm and humid air surge ahead of the cold front and increasing winds will result in the possibility of strong to severe thunderstorms Thursday into Thursday evening. The Storms Prediction Center has all of our forecast region in a Slight Risk for Severe Thunderstorms for Thursday and Thursday night, except for northern Garrett, northern Allegany, and western Washington Counties in Maryland. The main threat with these possible severe thunderstorms will be damaging winds given the wind field. Most recent guidance is indicating that the best forcing will be north of the forecast area, therefore leading to lower confidence in the severe threat. If storms develop, there is a high ceiling for impacts although westerly downsloping flow over the forecast are combined with lack of forcing may inhibit convection from developing. We will continue to monitor as Thursday gets closer.
The Weather Prediction Center has Garrett County in Maryland in a Slight Risk for Excessive Rainfall Thursday into Thursday evening. This indicates that heavy rainfall, accompanying frequent showers and strong thunderstorms, could lead to isolated flooding in places.

In the wake of the cold front, temperatures will be about 10 to 15 degrees cooler compared to the day before. Precipitation lingers into Friday morning, although surface high pressure building overhead yields dry conditions and decreasing cloud cover through the day.

KEY MESSAGE 2...A warm front is spawning a couple of showers in parts of Northeast Maryland and far southern Maryland. A thunderstorm cannot be ruled out in parts of the region.

A warm front, currently wiggling northward across east-central Virginia and southern Maryland, is spawning isolated to scattered showers during the early morning hours this morning. A rumble of thunder cannot be ruled out over the next 1 to 3 hours. Areas off to the west should stay dry. Additional showers are moving across southwest Pennsylvania and will clip northwestern Garrett County in Maryland over the next hour or two.

KEY MESSAGE 3...Thunderstorm potential will return late Sunday into Monday.

Broad low pressure remains in the region Saturday. A second cold front may slide through the area, but dry weather is likely.
Temperatures will be seasonable, but the noticeable change will be the drier, less humid airmass along with breezy northwest winds.

Model spread increases considerably for Sunday into early next week as the next shortwave trough emanates from a closed low over central Canada. This will lead to low pressure developing between the Ohio Valley and east coast, potentially strengthening off the coast early next week. Based on the current spread in timing, precipitation chances could increase as early as Sunday, but there is more model agreement for Monday. While thunderstorms are possible, instability may be limited, especially depending on the northerly advance of the warm sector. Overall it will be less hot and humid compared to some of the recent events, so any threat for strong to severe storms will be more conditional. The largest spread in temperatures is Monday, dependent on the position of the fronts.

AVIATION /07Z WEDNESDAY THROUGH SUNDAY/
VFR conditions are expected through the TAF period. Most of any showers over the next 1 to 3 hours will lift and move northeast of the BWI and MTN terminals. No significant reductions in ceilings or visiblities are expected. Winds will turn more southwesterly throughout today.

Primarily VFR conditions are expected on Thursday. Background winds will be out of the southwest on Thursday, and could gust in excess of 30 knots at times. Temporary drops to sub-VFR conditions and even stronger winds may be possible in thunderstorms Thursday afternoon.

VFR conditions are likely Saturday but northwesterly winds may gust to around 25 kt. The next frontal system may approach Sunday but is more likely to bring showers and thunderstorms Monday.

MARINE
A few showers will move across parts of the far northern zones of the Chesapeake Bay and the zones adjacent to far southern Maryland as a warm front lifts northward. Winds shift to southwest today which may support Small Craft Advisories for portions of the waters. SCAs appear likely on Thursday in southwesterly flow. Gale force winds are possible Thursday afternoon over the northern Tidal Potomac and northern portions of the Chesapeake Bay. SMWs will also likely be needed as thunderstorms move over the waters on Thursday as strong to severe thunderstorms potentially track over the waters. Small Craft Advisories are possible Saturday in northwesterly flow.
Winds may be lighter Sunday as high pressure passes to the south.

TIDES/COASTAL FLOODING
Tides will have the potential to reach Minor Flood, especially Annapolis today. Other sites will show and increase as well as an increasing southwesterly flow evolves ahead of Thursday's front.



LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.