Forecast Discussion for Willowsford Farm and vicinity from the NWS in Sterling, Virginia

000
FXUS61 KLWX 060149
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
949 PM EDT Sun Jul 5 2020

.SYNOPSIS...
Weak surface high pressure continues to build over the Atlantic
through Tuesday. Meanwhile, upper-level ridging builds in
across the area as well. Cutoff low pressure will develop to the
south for Wednesday and it may impact the area later in the
week.

&&

.NEAR TERM /THROUGH MONDAY/...
Showers and thunderstorms have mostly ended early this evening.
A few scattered showers persist over the central Shenandoah
Valley but have been slowly dissipating within the last hour. A
few additional showers are also visible on radar just north of
the Mason Dixon Line, which have also been weakening. Therefore
don`t expect any additional convective activity through the
overnight in which conditions will remain dry. Some patchy fog
is also plausible overnight, but should remain confined to the
valley areas. Warm and humid conditions are expected to continue
overnight with surface temperatures in the upper 60s to low 70s
and dew points in the 70s as well.

Latest WV imagery shows weak ridging working its way into the
region. As a result, weak high pressure will remain overhead for
Monday. However a weak shortwave traveling southeastward along
the ridge axis, will cause enough lift to spark another round
of convection Monday afternoon. Similar to today, high MU CAPE
values (around 2000 J/Kg) coupled with a better 0-6KM shear
profile of 20-25 kts will provide an enhanced environment for
more organized multicell clusters. For that reason SPC has place
much of the forecast area under a marginal risk for severe
weather. Damaging winds would be the primary risk with any
storms, but some hail cannot be ruled out as well. Otherwise,
expect another hot and humid day with heat indices climbing to
the mid-upper 90s for most.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
Any convective activity that develops Monday is expected to
mainly die down by Monday evening as the previously mentioned
shortwave slides southeastward; along with losing the daytime
heating. With weak high pressure still in place, expected Monday
night into Tuesday to remain warm, humid, and dry. The
continuation of the hot and humid trend persists through
Tuesday. The aforementioned ridge will begin to slide offshore
throughout the day on Tuesday, allowing yet another weak
shortwave to fire off additional convection Tuesday afternoon
and early evening.


&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
A warm and potentially fairly stormy pattern exists through the long
term. To start, on Wednesday a weak upper low be near or just south
of the region. This low lingers Thursday. The location of this low
will help dictate how stormy the weather is, with a closer locale
likely resulting in more afternoon thunderstorms and slightly cooler
temperatures. Friday and Saturday, uncertainty grows, with some
guidance kicking the upper low east ahead of a stronger trough
approaching from the west, while others keep the low around. This
will significantly affect the forecast, but uncertainty is high.
Bottom line, however, is that slightly warmer than normal
temperatures are likely, but the extent of thunderstorms is a more
uncertain.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
Expect mainly VFR conditions across the terminals overnight
with the exception of CHO and MRB which could see some MVFR/IFR
CIG/VSBYs as areas of patchy fog are expected to develop.
However, confidence remains low in this regard.

Generally expecting VFR at all terminals through Tuesday.
However, there will be a chance for afternoon showers and storms
each day, given the hot and humid air mass we are stuck in.
This threat will generally end once the sun sets each evening.

Main concern Wednesday and Thursday will be potential for early
morning fog and afternoon thunderstorms. Both of these concerns
are most likely to affect CHO and MRB.

&&

.MARINE...
Light southerly winds (below SCA) are expected over the waters
through Tuesday. Isolated to scattered showers and thunderstorms
are expected Monday and Tuesday afternoons. Special Marine
Warnings may be needed for any stronger storms that form.

Mainly light winds on the waters Wednesday and Thursday, with the
primary hazard being potential for afternoon thunderstorms both
days.

&&

.TIDES/COASTAL FLOODING...
Southerly flow continues over the next several days, which will
help to keep anomalies generally elevated. Could see minor
coastal flooding in many of the same spots this evening/tonight
yet again. For now though, am holding off, as subtle shifts in
the wind speed/direction could lead to quick drops in the
anomalies, which could quickly bump the forecast back down. So,
will hold off on any advisories at this time.

&&

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

&&

$$
SYNOPSIS...MSS
NEAR TERM...MSS
SHORT TERM...MSS
LONG TERM...RCM
AVIATION...RCM/CJL
MARINE...RCM/MSS
TIDES/COASTAL FLOODING...CJL

NWS LWX Office Area Forecast Discussion