819
FXUS61 KLWX 120129
AFDLWX

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

.SYNOPSIS...
A weak area of low pressure passes off to the southeast while
high pressure returns through Thursday leading to mostly dry
conditions. A cold front tracks through the area on Friday
leading to renewed shower and thunderstorm chances. High
pressure settles over the area this weekend. Next week looks to
become hot as a strong upper ridge builds towards the region.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
High pressure settles over the Mid-Atlantic back into the
Tennessee Valley tonight. This allows winds to go calm overnight
with some lingering high clouds overhead. Another round of
patchy fog is possible overnight as moisture gets trapped
underneath developing radiation inversions. The most likely area
for such fog development would be from I-81, especially within
river and mountain valleys. Forecast low temperatures stay on
the cool side with widespread 50s expected.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
The trough axis anchoring the eastern U.S. should more or less
consolidate into a closed low off the New England coastline on
Wednesday. The trailing synoptic flow turns more west-
northwesterly in nature with a gradual increase in mid-level
heights overhead. Rebounding heights coupled with a shift to
low-level southwesterly winds will aid in a warming trend for
the middle to latter portions of the work week. The increase in
heights aloft along with high pressure at the surface should
yield a mostly sunny day across the region. This dry pattern
persists through Thursday. Humidity will actually remain fairly
low for this time of year, as there isn`t a great plume of
moisture being pulled in, even amidst southerly flow. Dew points
are forecast to reach the upper 50s to low 60s on Wednesday,
then a few degrees higher on Thursday.

By Thursday afternoon, forecast 850-mb temperatures peak in the
14-17C range. Mixing this air mass dry adiabatically to the
surface would yield highs in the upper 80s to low 90s. Thursday
night`s low temperatures turn to more typical June levels,
generally in the mid 60s to low 70s.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Surface high to our east moves well out into the Atlantic Ocean
Friday, as a weak cold front dips south into the area during the
second half of the day. Southwesterly flow is likely to produce the
highest temperatures of the week, with highs reaching the lower 90s,
with mid 90s most likely in central VA. The downslope component of
the wind and previous days of dry conditions should limit heat
indices to the upper 90s.

Scattered showers and thunderstorms are likely to develop along the
cold front. A severe thunderstorm or two is possible. However,
westerly flow aloft tends to diminish severe storm threat in this
area, and instability will be tempered by low to mid 60s dew points.
Any delay in the FROPA arrival will push storms into the nighttime,
which should further limit the severe potential. Something to
monitor in the days to come.

High pressure builds across the region over the weekend, bringing
slightly above normal highs in the mid to upper 80s and dry
conditions. Overnight lows remain mild in the 60s, though upper 50s
possible for most of the area Saturday night.

Next week looks to start exceedingly hot as mid to upper level
ridging takes hold across much of the eastern CONUS. Based on
various ensembles, the mid-level ridge will be near or over our area
Monday and Tuesday. This is likely to push afternoon highs in the
mid to upper 90s.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions with light winds expected really through at least
Thursday night.

Winds turn southerly Wednesday afternoon, albeit still AOB 10
knots. Winds will then increase into Thursday ahead of an
approaching cold front to around 15 to 20 knots out of the
S/SW.

A cold front moving across the area Friday afternoon into Friday
evening will bring scattered showers and thunderstorms. The stronger
storms could produce brief periods of sub-VFR conditions and gusty
winds. High pressure builds in behind the cold front Friday night
into the weekend. Outside of any shower/storms on Friday, VFR
conditions are expected through the weekend.

&&

.MARINE...
Winds remain below advisory levels through the first half of
the day on Thursday. Winds will shift to southerly the second
half of Wednesday but should remain fairly light. This will
change on Thursday as southerly winds increase ahead of an
approaching cold front. Southerly channeling effects become much
more prominent from Thursday evening into the night, especially
over the wider portions of the Chesapeake Bay. This will likely
need a Small Craft Advisory as we get closer in time.

Southerly channeling could produce SCA conditions in the open waters
of the Chesapeake Bay Friday afternoon. A cold front is forecast to
cross the waters during the second half of Friday, bringing
scattered showers and thunderstorms. Any strong storm could be
capable of producing wind gusts of 35 knots or greater.

Another period of SCA conditions is possible behind the cold front
early Saturday morning through mid Saturday afternoon as northerly
channeling produces gusts of 20-25 knots.

&&

.TIDES/COASTAL FLOODING...
No tidal flooding is expected through Wednesday as winds remain
light. However, as winds turn southerly late Wednesday into
Thursday, tidal anomalies will rise as a result. This could
result in some minor tidal flooding towards the end of the week.
No flooding is forecast at this time, but the current forecast
does gradually rise some of the more sensitive sites well into
action stage, so it will certainly be close.

&&

.CLIMATE...
High temperatures could approach records on both Thursday and
Friday afternoon. Below is a list of record high temperatures
for June 13th and 14th, the year the record was set, and the
current forecast high temperatures for those days.

                                    Thursday Jun 13th
Climate Site                  Record High     Forecast High
Washington-National (DCA)     96F (1954)          91F
Washington-Dulles (IAD)       95F (2017)          91F
Baltimore (BWI)               97F (2017+)         91F

                                     Friday Jun 14th
Climate Site                  Record High     Forecast High
Washington-National (DCA)     98F (1954)          94F
Washington-Dulles (IAD)       98F (1994)          94F
Baltimore (BWI)               98F (1994)          93F

+ 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...None.

&&

$$

SYNOPSIS...BRO
NEAR TERM...CJL/ADM
SHORT TERM...BRO/CJL
LONG TERM...KRR
AVIATION...CJL/ADM/KRR
MARINE...CJL/KRR
TIDES/COASTAL FLOODING...LWX
CLIMATE...LWX