National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KLWX 040737
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
337 AM EDT Sat Apr 4 2020

.SYNOPSIS...

Weak high pressure will build in from the Ohio Valley through
Sunday morning. A weak cold front will move in Sunday night
before becoming diffuse on Monday. A low pressure system will
approach from the midwest on Wednesday.

&&

.NEAR TERM /THROUGH TONIGHT/...

A mid-level circulation is clearly evident on all three GOES-16
water vapor channels and likely extends from 700 mb up to the
300 mb level. This circulation is significantly stronger than
what models are initializing early this morning. A few showers
have been observed over central PA this morning and are working
their way southward. The mid-level circulation is expected to
continue pushing southward this morning and move south of the
area by 18Z. Expect increasing cloudiness with lowering cigs and
the risk of a few sprinkles or very light showers between 09Z-
15Z for areas in MD east of Rt 15 and I-95. It will be about 5
degs cooler than yesterday with highs around 60 or lower 60s.

We`ll gradually lose the low clouds overnight, but high clouds
will start arriving at the same time. Overall, mostly cloudy
skies expected tonight. Lows will be in the mid 40s.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...

Few-sct showers are possible Sunday into Sun evening as weak
cold front approaches from the west and eventually crosses the
area. The front is expected to push south of the area late Sun
night and then become diffuse Monday. It should be on the warm
side with ridge axis overhead. Showers may enter the fcst area
again late Monday night and Tue as a weak area of low pressure
forms along a developing frontal zone attached to low pressure
over the upper Midwest.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...

The subtropical jet is forecast to move northward into the mid-
Atlantic region on Tuesday while a weaker upper level jet drops
southward from the Great Lakes region. This will lead to upper
level ridging over the central plains and parts of the
midwestern US through Wednesday. Shortwaves are forecast to move
along this ridge and down into our region on Wednesday. A
surface low associated with these disturbances will move to our
north bringing a chance for showers Tuesday and Wednesday.
Precipitation will likely be limited by the lack of good forcing
and a general westerly flow transporting in a drier downsloping
air. Temperatures during this period should slowly trend
upwards into the 70s with overnight lows in the 40s and 50s.


A strong upper level low is forecast to drop southward into the
central US from the Canada on Thursday. A surface low associated
with this upper level low will move through the Great Lakes region
and eastern Canada. A cold front will approach and move through our
region on Thursday bringing another chance for rain to our region.
There remains some uncertainty on the strength and timing of an
upper level jet which could help influence the location and amount
of precipitation that our region receives. The front should be
through our area by Friday morning but the low to our north is
forecast to occlude west over the NE US which could bring a back
end chance for showers again on Friday. Behind the frontal passage,
high pressure builds over our region on Friday along with a cooler
air mass which could bring a spring chill to our area.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...

Increasing clouds today with lowering cigs but still VFR. Low
clouds start lifting tonight. Few showers are expected Sun with
a frontal passage expected Sunday evening along with shifting
winds. Front becomes diffuse Monday. No sig wx Mon and Tue.

Showers will be possible Tuesday and Wednesday. Winds will be mainly
out of the west with periods of variable winds. VFR conditions
expected at this time for Tuesday and Wednesday. More widespread
rain expected Thursday which may lead to subVFR conditions.

&&

.MARINE...

Winds will gradually diminish through early this afternoon, then
light and variable winds tonight through at least the middle of
next week. No hazards expected.

&&

.TIDES/COASTAL FLOODING...

Water levels are expected to rise today into Sunday morning with
potential for moderate coastal flooding at Straits Point and
possibly Annapolis beginning tonight and continuing through Sun
night. Advisories may also be needed for today. At the very
least, will likely be issuing a Coastal Flood Watch for St.
Mary`s County before the end of my shift valid for tonight
through Sunday evening.

&&

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

&&

$$
SYNOPSIS...LFR
NEAR TERM...LFR
SHORT TERM...LFR
LONG TERM...JMG
AVIATION...LFR/JMG
MARINE...LFR/JMG
TIDES/COASTAL FLOODING...LFR