026
FXUS61 KLWX 020751
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
351 AM EDT Tue Jul 2 2024

.SYNOPSIS...
Surface high pressure will continue to pivot across the Mid-
Atlantic today before shifting offshore throughout the day on
Wednesday. A frontal boundary will approach the area and stall
to our northwest through the end of the week, before passing
through the forecast area this weekend.

&&

.NEAR TERM /THROUGH TODAY/...
High pressure will remain overhead with dry conditions and
mostly sunny skies. Relative humidity will remain low as dry
air remains in place. Aloft, ridging builds over the east coast
leading to continual warming of temperatures. Temperatures will
be a few degrees warmer compared to yesterday with highs in the
mid 80s for most. Those at higher elevations will stay in the
low to mid 70s.

Overnight low temperatures will be slightly warmer compared to
last night with lows in the 60s for most. Those west of I-81
will see low temperatures in the mid 50s to low 60s.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
Temperatures continue to gradually warm on Wednesday as upper
level ridging builds over the east coast. At the surface,
aforementioned high pressure will shift offshore as return flow
ushers in warm and moist air. High temperatures will be int he
mid 80s to low 90s with overnight lows in the mid 60s to low
70s. Wednesday will start out dry with mostly sunny skies.
However, an approaching cold front will bring increased cloud
cover and and a slight chance of showers and thunderstorms to
those west of I-81 Wednesday night into Thursday. Most
locations will remain dry though with increasing mugginess.

Warming trend continues for the 4th of July, as upper level
ridging pivots off the east coast. An approaching frontal
boundary and pre-frontal pressure trough will lead to scattered
to numerous showers and thunderstorms, mainly that afternoon and
into the early evening. High temperatures will soar into the
mid 90s most with heat indices reaching triple digits for some.
Instability increases throughout the day with SBCAPE values
exceeding 1500 J/Kg. However, there still remains a good bit of
uncertainty regarding any convection on Independence day with
weak lapse rates (<6 C/km) and Bulk Shear(<30 knots). Overnight
low temperatures will be in the 70s for most.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
The end of this week and start of the weekend look to be active as a
weak surface frontal boundary is stalled over the area. Aloft,
southwesterly flow prevails as the region is in between a slow
moving upper trough over the Great Lakes, and a ridge over the Deep
South. Deep moisture from the Gulf of Mexico works its way north
into our area, bringing PWATs over 2" and dew points in the low to
mid 70s. Scattered to widespread afternoon showers and thunderstorms
are expected each day Friday and Saturday, especially along and east
of the Blue Ridge. A few strong to severe storms are possible given
the ample instability and moisture present. Afternoon highs reach
the low to mid 90s, with peak heat indices between 102-107 east of
the Blue Ridge, and 97-102 west of the Blue Ridge.

The upper trough over the Great Lakes slides northeast as a weak
surface high builds over the OH Valley. The weak frontal boundary
over the area is pushed southward, with drier air moving at least
into the northwestern half of the CWA. A tight moisture gradient is
likely to be present. Isolated to scattered showers/storms focus
mainly in Central VA to southern MD. A slight dip in temperatures to
the upper 80s to low 90s, though less humidity as heat indices
remain below 100 Sunday.

This break in convection/humidity is short lived as the frontal
boundary lifts north over the area as a warm front Monday. Unsettled
weather with scattered afternoon thunderstorms return for the start
of next week.

&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
Prevailing VFR conditions are expected today through Wednesday
night with high pressure in place. Winds remain light and shift
to southeasterly throughout the day today. High level clouds
are expected throughout the day with some low level clouds this
afternoon. Winds remain light and southerly on Wednesday, with
MRB, BWI and MTN seeing the strongest gusts of up to 15 knots.

VFR conditions continue for the most part on Thursday with
southwesterly winds in the morning shifting to westerly in the
afternoon. Scattered to numerous showers and thunderstorms are
expected in the afternoon and could cause conditions to
deteriorate to sub-VFR.

Scattered to widespread showers and thunderstorms are likely across
the area each afternoon Friday and Saturday. Any thunderstorm moving
over a terminal will be capable of producing brief periods of sub-
VFR conditions, in addition to gusty winds and lightning strikes.
Thunderstorm activity could linger into the evening at IAD, DCA,
BWI, and MTN, then clear out overnight. Outside of convection, VFR
conditions are expected.

&&

.MARINE...
Mild and dry conditions are expected across all waters today as
high pressure pivots overhead. Southeasterly winds remain below
SCA criteria through tonight. Winds shift to southerly on
Wednesday with channeling resulting in SCA criteria gusts in the
afternoon and evening.

On Thursday, winds remain out of the south/southeast with SCA
criteria gusts possible in the southern portions of the waters.
SMWs may be needed during showers and thunderstorms that
afternoon.

A weak frontal boundary in place over the local waters will result in
at least scattered thunderstorms each afternoon Friday and Saturday.
These storms will be capable of producing wind gusts in excess of 35
knots and frequent lightning strikes. Special Marine Warnings may be
needed as storms move across the waters. Thunderstorm activity
diminishes in the evening, though a storm or two could last into the
night. Outside of thunderstorm activity, southerly winds around 10-
15 knots are expected.

&&

.TIDES/COASTAL FLOODING...
Tidal anomalies are forecast to steadily rise through the week
as southeast to south winds prevail. No coastal flooding
concerns today as most, if not all, sites remain below Action
Stage. However, by Wednesday morning some sensitive locations
will reach Action Stage, and Annapolis is the most likely to go
into minor flooding Wednesday morning. Additional periods of
coastal flooding are possible during the morning high tide
Thursday and Friday.

&&

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

&&

$$

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