146
FXUS61 KLWX 120129
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
929 PM EDT Sat May 11 2024

.SYNOPSIS...
Low pressure moving across the area will bring showers and a few
thunderstorms through tonight. A lingering upper level
disturbance may allow showers to persist into Sunday along with
cool temperatures. Drier conditions return with brief high
pressure Monday. A slow moving low pressure system will bring
more unsettled weather Tuesday into Wednesday.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
The initial band of light to moderate rain showers has nearly
cleared the entire forecast area. As of 900 PM, this decaying
swath of showers stretches from Cecil County down through the
Eastern Shore into Calvert County. After locations cleared in
the wake, low to mid clouds continue to filter in leading to
mostly cloudy skies. Farther upstream, a cluster of severe
thunderstorms originally from southwestern Pennsylvania has
begun exiting Garrett County. As this feature tracks near a warm
front, a lingering severe risk persists into northern Maryland
and portions of the eastern West Virginia panhandle. This storm
cluster will push across the I-81 corridor by around 10 PM
before continuing its trek eastward. For those looking to view
the geomagnetic storm and resultant aurora, increased clouds
from this system may hinder viewing in spots.

Heading through the night, conditions will dry out from west to
east. The 12Z HREF mean keeps most areas along and east of U.S.
15 in low clouds with more clearing off to the west. Forecast
low temperatures drop into the mid 40s to low 50s.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
The aforementioned cold front will move east of the area Sunday
morning, though some residual moisture on the backside of the broad
low could bring some on-and-off showers along/north of US-50 through
Sunday afternoon. Conditions dry out Sunday evening as high pressure
builds in from the west. Highs generally be in the 60s, with some
low 70s possible in Central VA Sunday afternoon. Overnight lows
mostly in the 40s to low 50s.

For Monday, expect dry conditions as high temperatures reach back to
the mid to upper 70s. An approaching upper disturbance looks to hold
off until late Monday night, when scattered showers move into areas
west of the Blue Ridge.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Monday looks to be our driest day of the next 7 days with mid level
ridging overhead and surface high pressure sitting just to the south
of the region. This will yield a seasonable Spring day with high
temperatures in the mid to upper 70s and overnight lows in the 50s.

Unfortunately, the dry time will be brief as an upper trough
develops in the lee of the Rockies, and deepens as it tracks
eastward from the mid-Mississippi River Valley during the middle
part of workweek. Meanwhile, high pressure will shift off the VA/NC
coast Tuesday into Wednesday allowing for south to southeasterly
return flow to ensue. This will allow Atlantic and eventually Gulf
of Mexico moisture to increase across the region yielding daily
isolated to scattered chances for showers and thunderstorms.
Uncertainty remains in the placement and timing of the heaviest
precipitation with a focus midweek (late Tuesday into Wednesday).
This is due largely in part to a warm frontal boundary that will be
lifting northward into the region. The severe weather threat appears
to be minimal with richer moisture suppressed toward the Gulf Coast.
Locally heavy rainfall is possible especially during the midweek
timeframe due to increasing moisture and the placement of a warm
front draped nearby. High temperatures will remain at or slightly
below normal midweek. Expect highs in the low to mid 70s Wednesday
and mid to upper 70s Thursday. Lows will fall into the mid to upper
50s.

Low pressure and its resulting trough depart offshore Thursday
into Friday. A cold front will quickly follow bringing in drier
air as high pressure builds over eastern Canada. The dry time
once again will be short lived as another trough and area of low
pressure approach from the Ohio River Valley.

&&

.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
In the wake of the earlier band of showers, all TAF sites have
recovered to VFR conditions. Based on the latest nighttime
satellite imagery, low clouds have begun to develop in many
spots. MVFR ceilings become likely overnight, continuing until
around daybreak. Some showers exiting western Maryland will also
impact all downstream locations outside of KCHO. Given a history
of thunder, KMRB features a VCTS group from 10 PM until
midnight.

The cold front sweeps through early Sunday morning, causing
winds to shift northwest behind the front. Gusts to around 20
knots are likely from late morning through the afternoon Sunday.
VFR conditions expected through Monday as high pressure
returns.

VFR conditions are expected with high pressure nearby. Sub VFR
ceilings along with a showers and a few thunderstorms are possible
Tuesday and Wednesday as an area of low pressure and front push into
the region. Shower and thunderstorm chances look to linger Thursday
with high pressure briefly returning Friday. South to southwesterly
winds are expected Monday before switching to the south and
southeast Tuesday and Wednesday. Gusts of 15 to 20 kts can be
expected each afternoon.

&&

.MARINE...
A cluster of showers with a history of severe weather continue
to press eastward across western Maryland and the northeastern
West Virginia panhandle. Given the decrease in lightning and
near-zero instability over the waters, do not expect any impacts
later this evening.

Winds increase this evening into part of tonight just ahead of
the approaching cold front. A Small Craft Advisory is in effect
for the waters of the Chesapeake Bay and Lower Tidal Potomac
through 4 AM Sunday. Thereafter, winds should diminish late
tonight.

Winds turn northwest behind the cold front Sunday morning, and could
gust to SCA levels for a few hours during the afternoon. Winds
diminish Sunday night into Monday as high pressure builds into the
region.

SCA conditions will likely continue Monday, Tuesday, and Wednesday
as low pressure approaches from the south and high pressure pushes
offshore. South to southeasterly winds will gusts up to 20 kts each
day with the potential for a few thunderstorms on both Tuesday and
Wednesday afternoon/evening.

&&

.TIDES/COASTAL FLOODING...
Additional periods of coastal flooding are expected tonight
with a number of tidal sites in Coastal Flood Advisories. This
extends over additional high tide cycles at many of these spots.
Afterwards, water levels should drop off Sunday as northwest
flow kicks in across the area. However, a shift to easterly
onshore winds Sunday evening into early Monday could bring
anomalies back up again.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Coastal Flood Advisory until 3 PM EDT Sunday for DCZ001.
MD...Coastal Flood Advisory from 8 AM to 3 PM EDT Sunday for MDZ011.
     Coastal Flood Advisory until 1 PM EDT Sunday for MDZ014.
     Coastal Flood Advisory until 11 AM EDT Sunday for MDZ016-018.
     Coastal Flood Advisory until 9 AM EDT Sunday for MDZ017.
     Coastal Flood Advisory from 11 AM to 5 PM EDT Sunday for
     MDZ508.
VA...Coastal Flood Advisory until 3 PM EDT Sunday for VAZ054.
     Coastal Flood Advisory until 11 AM EDT Sunday for VAZ057.
WV...None.
MARINE...Small Craft Advisory until 4 AM EDT Sunday for ANZ530>534-537-
     538-543.

&&

$$

SYNOPSIS...KRR
NEAR TERM...BRO/KRR
SHORT TERM...KRR
LONG TERM...LFR
AVIATION...LFR/BRO/KRR
MARINE...LFR/BRO/KRR
TIDES/COASTAL FLOODING...BRO/KRR/LFR