FXUS61 KLWX 201914

AFDLWX



Area Forecast Discussion

National Weather Service Baltimore MD/Washington DC

314 PM EDT Sun Sep 20 2026



.WHAT HAS CHANGED...



Nothing.



&&



.KEY MESSAGES...

- 1) Numerous showers expected through this evening. Turning

     much cooler Monday and through the rest of the week.



- 2) Cool & wet conditions persist through the end of the week,

  with drier conditions heading into the weekend. 



&&



.DISCUSSION...



KEY MESSAGE 1...Numerous showers expected through this evening. Turning

much cooler Monday and through the rest of the week.



Extensive cloudiness has limited instability all day with VIS 

imagery and NUCAPS data showing only southern MD having received

enough sunshine for thunderstorms to potentially develop later

this afternoon or evening. Otherwise, a weak area of low 

pressure will pass through the area early this evening and 

should bring a round of light showers to most areas through mid 

evening, except in the south. The front will sink south

overnight with showers ending, with clouds lowering. 



More showers will arrive in the west toward daybreak as the next 

shortwave-trough and weak area of low pressure approaches the

area. These showers will slowly progress east during the

afternoon Monday. The period of heaviest rainfall looks to be

Monday night/early Tuesday when onshore flow/moisture advection

is strongest combines with a weak low to mid-level low pressure.



High pressure then builds south from the Northeast Tue setting

up a strong cold air damming event supporting well below normal

temperatures and cloudy conditions. 



KEY MESSAGE 2...Cool & wet conditions persist through the end 

of the week, with drier conditions heading into the weekend. 



Intermittent showers remain possible mid-to-late week as a 

lingering frontal boundary sags to the south. Additionally, a 

strong coastal low begins to track north close to the Maryland 

coast Thursday and into Friday, which will bring gusty 

conditions to the region. This strong onshore flow could bring 

minor coastal flooding to sites along the Chesapeake Bay. See 

the coastal flooding section below for more information. 



As this coastal low tracks to the north, dry mid-level air from the 

upper Midwest moves in overhead. This will create somewhat drier 

conditions heading into the weekend, although there is a bit of 

model discrepancy on how slow the coastal low will be moving out of 

the area. Winds could stay elevated until this system is well north 

of the Mid-Atlantic. Temperatures stay slightly cooler-than-average 

during this time, although gradually increase near the end of the 

week as any lingering shortwave disturbances track offshore. 





&&



.AVIATION /18Z SUNDAY THROUGH FRIDAY/...



A cold front will drop south this evening supporting numerous

showers. Winds shift to the north tonight with IFR conditions

developing. IFR cigs persist through mid week.



Intermittent sub-VFR conditions likely continue through Thursday as 

additional showers move through the Mid-Atlantic, reducing CIGs and 

VSBYs. Conditions potentially improve somewhat on Friday as a trough 

moves north out of the region. Gusty winds remain a possibility 

through the end of the week due to onshore flow, with gusts between 

15-25 knots possible. Winds flow north to northeasterly. 



&&



.MARINE...



Winds have relaxed a bit this afternoon, but are expected to

strengthen Monday night through early Thursday. Additional SCAs

will be needed. 



Wind gusts will be strongest on Thursday over the Bay as a coastal 

storm tracks to the north off the East Coast. Sustained winds 

between 20-25 knots are possible with as winds flow northeasterly. 

Winds stay elevated on Friday, flowing due north. On and off showers 

are possible over the waters as multiple shortwave disturbances move 

through. 



&&



.TIDES/COASTAL FLOODING...



Water levels remain elevated as onshore flow has developed.

Stronger NNE winds Monday afternoon will push the water south

into the mouth of Chesapeake Bay. This excess water is expected

to slosh back mid week resulting in widespread minor coastal

flooding, perhaps moderate at Annapolis.



&&



.LWX WATCHES/WARNINGS/ADVISORIES...

DC...None.

MD...Coastal Flood Advisory until 6 AM EDT Monday for MDZ014.

VA...None.

WV...None.

MARINE...Small Craft Advisory from 6 AM to noon EDT Monday for 

     ANZ531>534-539>541-543.



&&



$$



DISCUSSION...LFR/SRT

AVIATION...LFR/SRT

MARINE...LFR/SRT