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Area Forecast Discussion (AFD)

Issued by Baltimore/Washington (LWX)

                            
000
FXUS61 KLWX 230800
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
400 AM EDT Fri Aug 23 2019

.SYNOPSIS...A cold front will cross the area today and move
into the southern mid-Atlantic and southeast states this
weekend. Strong high pressure will build north of the region 
tonight and settle over northern New England and Atlantic Canada
through early next week. A tropical depression could form over
the weekend as it moves near the southeast coast.

&&

.NEAR TERM /THROUGH TONIGHT/...

Showers are expected today as cold front crosses the area and
intercepts a moisture-laden air mass. Across far southern 
areas along the LWX/AKQ CWAs where the front will be slow to
clear this afternoon, there should be enough destabilization 
to allow t-storms to develop. Enough shear and instability
appear present for a risk of a severe thunderstorm or two mainly 
over southern St. Marys County and the lower Potomac and
Chesapeake Bay waters. Front clears southern areas tonight with
showers gradually ending. Much cooler today with highs around
80.


&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...

High pressure will build north of the region tonight and hold
strong through early next week. It should be pleasant and mainly
dry, but areas along the lower Chesapeake Bay may still have a
slight risk of a shower or two due to onshore flow. 

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...

For the most part, high pressure will be in control of the weather 
and provide dry and slightly cooler conditions Monday through 
Tuesday. An onshore flow from the western Atlantic could spawn a few 
showers or a thunderstorm, mainly Tuesday and across the Potomac 
Highlands.

The high pressure will move to the northeast Tuesday night and 
Wednesday. A cold front will approach the region from the west. 
Ahead of the front, the warmth and humidity will return due to a 
developing and persistent southerly flow. A chance for additional 
showers and thunderstorms will be present, especially Wednesday 
afternoon and evening. 

The cold front is expected to push to the southeast and move 
offshore the East Coast Thursday. A cooler dome of high pressure 
will build behind the front from the Upper Midwest and Great Lakes 
region. Cooler and drier air will ensue with this high. 

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...

MVFR cigs with showers mainly this morning across northern
terminals and all day at KCHO. Conditions improving tonight.

VFR conditions for all terminals Monday through Tuesday night. Any 
isolated shower or thunderstorm could briefly bring conditions to 
MVFR and probably would be mainly near MRB or CHO Tuesday.
Winds northeast 5 to 10 knots Monday, then variable Monday night. 
Winds southeast around 5 knots Tuesday and Tuesday night.

&&

.MARINE...

SMWs may be required for the far southern waters this afternoon.
Improving weather tonight as cold front pushes south. Will need
to monitor northerly channeling and potential TC passing
offshore early or mid next week for increasing winds and
possible SCAs.

No marine hazards expected Monday through Tuesday night. Winds 
northeast 10 knots Monday, then light and variable Monday night. 
Winds becoming southeast 10 knots Tuesday and Tuesday night.

&&

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

&&

$$
SYNOPSIS...LFR
NEAR TERM...LFR
SHORT TERM...LFR
LONG TERM...KLW
AVIATION...LFR/KLW
MARINE...LFR/KLW