Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
895
FXUS61 KLWX 131847
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
247 PM EDT Thu Jun 13 2024
.SYNOPSIS...
High pressure moves further offshore today. A cold front tracks into
the region Friday, with increasing shower and thunderstorm chances.
Secondary high pressure builds back in for the weekend with lower
humidity and slightly cooler temperatures. Hot and humid conditions
return next week as a strong upper ridge impacts the area.
&&
.NEAR TERM /THROUGH TONIGHT/...
High pressure will continue to slide further offshore later
today. Some scattered cumulus clouds will continue to form early
this afternoon and continue to build throughout the remainder
of the day. Afternoon highs will be in the mid to upper 80s for
most areas with even a few sites reaching 90 degrees. The high
terrain will likely top out in the upper 70s to low 80s.
With some subtle lift in the flow, cannot completely rule
out an isolated shower for the afternoon and evening hours and just
after sunset. While these showers will likely be fairly short-lived,
there is a non-zero chance for an isolated rumble of thunder given
the convective parameters in place. Showers and thunder chances
should fall off just after sunset with overnight lows dropping into
the 60s.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
Friday morning, conditions should be mostly dry with clouds
increasing from the northwest as a result of an approaching cold
front moving in from the Great Lakes region. Another above normal
temperature day is expected, with highs in the low 90s across the
lower elevations and mid to upper 70s for the mountains. The cold
front will likely become more negatively tilted as it approaches
areas along and east of the Blue Ridge which may enhance coverage
and intensity of any showers and thunderstorms that spawn. For now,
expecting isolated to scattered thunderstorms to develop Friday
afternoon and evening just ahead of the frontal passage. With
increased CAPE, slightly steep low-level lapse rates, and increased
flow aloft, a few of theses storms may become strong to severe. The
area of best chances for this looks to be across north-central to
northeast MD. The main hazards for these storms will likely be
damaging winds, with increasing DCAPE through the afternoon. Cannot
rule out some hail with these storms as well. Most convection likely
moves east of the area after midnight Friday. Overnight lows will
fall into the low to mid 50s across the mountains and slightly
warmer into the low to mid 60s further east across the lower
elevations.
Secondary high pressure will build in for the weekend, with
decreasing humidity and slightly cooler temperatures. Highs will
generally be in the low to mid 80s both days, with winds remaining
light. Overnight lows Saturday night will be in the 50s for most
areas, with gradual humidity increase Sunday night with lows in the
low 60s for most areas.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Upper level ridging sets up over the eastern half of
CONUS for the entirety of the long term period. Sunday will be the
coolest day of the long term period with high temperatures in the
80s for most. Those at higher elevations will stay in the mid to
upper 70s. With high pressure at the surface, dry conditions are
expected areawide. Dry conditions are expected overnight Sunday into
Monday with low temperatures 60s for most.
As we head into the workweek and the ridge settles overhead, above
average temperatures will be the main story. While there is a bit of
model discrepancy on exact high temperature forecasts, models agree
on above average temperatures each day. High temperatures each day
will be in the 90s with only those at highest elevations staying in
the 80s. With dew points in the upper 60s, heat indices will rise
into the upper 90s to even exceeding low 100s possible. Overnight
low temperatures will cool into the 60s to low 70s each night with
the metro areas staying in the upper 70s.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
VFR conditions are expected through early Friday, with gusts this
afternoon up to 15 knots at the terminals. Isolated showers are
possible this afternoon and evening but they should remain benign.
Cannot completely rule out a stray rumble of thunder but elected to
keep VCTS out of the TAFs. Some patchy fog is possible later tonight
and into early Friday but visibility restriction at the terminals
are not expected at this time.
By Friday afternoon, a cold front will approach the area and bring
the potential for isolated to scattered thunderstorms. Some of these
storms could become severe, especially for the more northeastern
terminals. Sub-VFR conditions may be briefly possible Friday
afternoon and evening with any of these showers and storms that
approach the terminals.
VFR conditions return for the weekend with light winds as a result
of reinforcing high pressure nearby.
VFR conditions are expected throughout the long term period with
high pressure and upper level ridging overhead. Southeasterly winds
on Sunday will shift to southerly on Monday. Dry weather is expected
both days with winds remaining light, blowing 5-10 knots.
&&
.MARINE...
An elevated pressure gradient over the waters this afternoon yielded
a Small Craft Advisory across much of the waters. Could see
additional SCAs on Friday with southerly channeling bringing gusts
near 20 knots at times during the afternoon and evening hours.
Additionally, SMWs may be needed for any strong to severe
thunderstorms that cross the waters during the day on Friday. High
pressure returns for the weekend. Cannot rule out SCA conditions
early Saturday with northerly channeling building for the open
waters especially.
Southeasterly winds on Sunday are expected to remain below SCA
criteria. By Monday morning, winds shift to southerly and will
primarily stay below SCA criteria. Winds in the lower portions of
the waters will near SCA criteria Monday evening, gusting up to 17
knots with a SCA being possible during this time.
&&
.TIDES/COASTAL FLOODING...
Current tidal anomalies remain slightly elevated, generally ranging
between 0.5 to 0.7 feet. At this point, only the sensitive locations
like Annapolis and Straits Point are expected to reach Action stage
during the next several high tides. Water levels do quickly drop off
over the weekend behind a cold front. North to northwesterly flow
should push a lot of the excess water back toward the south.
&&
.CLIMATE...
High temperatures early next week. Below is a list of record high
temperatures for June 17th, 18th, and 19th, the year the record
was set, and the current forecast high temperatures for those
days. Daily temperature records are currently only maintained at
DCA, IAD, BWI, and MRB. Others are shown for reference.
Monday Jun 17th
Climate Site Record High Forecast High
Washington-National (DCA) 99F (2022) 93F
Washington-Dulles (IAD) 96F (2022) 94F
Baltimore (BWI) 96F (2022+) 92F
Martinsburg (MRB) 98F (1939+) 91F
Charlottesville (CHO) 97F (2022) 93F
Annapolis (NAK) 96F (1939) 87F
Hagerstown (HGR) 96F (1952) 92F
Tuesday Jun 18th
Climate Site Record High Forecast High
Washington-National (DCA) 97F (1944) 95F
Washington-Dulles (IAD) 94F (2018+) 95F
Baltimore (BWI) 97F (1957+) 93F
Martinsburg (MRB) 99F (1943) 92F
Charlottesville (CHO) 96F (2014+) 93F
Annapolis (NAK) 96F (1957) 89F
Hagerstown (HGR) 95F (1957) 93F
Wednesday Jun 19th
Climate Site Record High Forecast High
Washington-National (DCA) 99F (1994) 95F
Washington-Dulles (IAD) 98F (1994) 95F
Baltimore (BWI) 99F (1994) 93F
Martinsburg (MRB) 96F (1994+) 92F
Charlottesville (CHO) 97F (2018) 94F
Annapolis (NAK) 96F (1993) 89F
Hagerstown (HGR) 97F (1994) 94F
+ indicates that value has been reached on multiple years, with
the year displayed being the most recent.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 5 AM EDT Friday for ANZ530>534-
537>543.
&&
$$
SYNOPSIS...ADM
NEAR TERM...ADM
SHORT TERM...ADM
LONG TERM...AVS
AVIATION...AVS/ADM
MARINE...AVS/ADM
TIDES/COASTAL FLOODING...LWX
CLIMATE...BRO