May 21, 2019
DC Climate Report
Last 72 Hours: Observations
Today: Sunny, with a high near 73°. Northwest wind 10 to 13 mph.
Tonight: Mostly clear, with a low around 55°. North wind 5 to 8 mph.
Wednesday: Sunny, with a high near 76°. Light and variable wind becoming northeast around 5 mph in the afternoon.
Wednesday Night: A chance of showers, mainly after 2am. Partly cloudy, with a low around 61°. South wind 5 to 7 mph. Chance of precipitation is 30%.
Thursday: A chance of showers, with thunderstorms also possible after 2pm. Partly sunny, with a high near 85°. Southwest wind 3 to 7 mph. Chance of precipitation is 30%.
Thursday Night: A chance of showers and thunderstorms, mainly before 8pm. Mostly cloudy, with a low around 69°. Chance of precipitation is 30%.
Friday: Mostly sunny, with a high near 85°.
Friday Night: Partly cloudy, with a low around 65°.
Saturday: Mostly sunny, with a high near 85°.
Saturday Night: Partly cloudy, with a low around 69°.
Sunday: Mostly sunny, with a high near 88°.
Sunday Night: Mostly cloudy, with a low around 69°.
Memorial Day: A chance of showers. Partly sunny, with a high near 85°. Chance of precipitation is 30%.
Latest Forecast | Forecast Archive | Observations Archive
FXUS61 KLWX 210759
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
359 AM EDT Tue May 21 2019
Canadian high pressure will stretch across the Great Lakes and
into the Mid Atlantic through Wednesday. As the high shifts
offshore Wednesday night, a warm frontal boundary will approach
from the southwest on Thursday. A frontal boundary will linger
nearby through much of the weekend.
.NEAR TERM /THROUGH TONIGHT/...
A canadian high pressure system will build into our region today.
Winds will be breezy and out of the northwest with wind guys upwards
of 25 mph possible due to a pressure surge behind the cold front
that exited our region last night. The breezy conditions will taper
off this evening with winds becoming light and variable. Skies will
remain mostly clear with a few linger higher clouds this morning
mainly over the WV eastern panhandle and western Maryland.
Temperatures will run slightly below average today in the low to mid
70s. Temperatures tonight will fall back into the upper 40s to
middle 50s under mostly clear skies.
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Canadian high pressure will remain in place over our region through
Wednesday afternoon. Skies will remain mostly clear with winds
starting out as light out of the north. High pressure will start to
shift out of our region to the Northeast as a warm front moves
through our area Wednesday evening and into Thursday. Winds will
become southerly by Wednesday afternoon and continue into Thursday
leading to a warming trend due to warm advection. Temperatures will
trend up into the 80s by Thursday. The frontal boundary will stall
over or near our region on Thursday. This boundary will have the
potential to act as a focus for the formation showers and
thunderstorms. The continued southerly flow through Thursday will
lead to advection of warm and moist air into our region which will
allow CAPE values to increase above 1500 and possibly as high as
3000 in some areas. Models are indicating that this will mainly be a
high CAPE and low shear environment. As the boundary will remain
stalled over our region, we can`t rule out that a few thunderstorms
could reach severe thresholds. There remains a lot uncertainty at
this time especially on where the front will stall on Thursday.
.LONG TERM /FRIDAY THROUGH MONDAY/...
Mid to upper level ridging is expected to persist through the
first half of the weekend, with mainly dry conditions winning
out the bulk of the time. This ridge will break down on Sunday
as the flow aloft becomes zonal, then turning cyclonic as a
shortwave digs into the northeast. At the surface, a lingering
frontal boundary will reside nearby Friday, lifting northward as
a warm front on Saturday as low pressure tracks north of the
Great Lakes. With strong ridging aloft and surface high pressure
anchored over the southeastern states, thinking shower/storm
chances will remain in the low end chance category at this
time, with any activity focused during peak heating hours in the
mountains and our northern zones, both Saturday and Sunday. Not
looking like a washout at all at this time, with temperatures
running in the 80s both days. A better shot of showers and
storms comes Monday as a shortwave trough digs across the Great
Lakes and into interior New England as the flow aloft turns
cyclonic. At the surface, another frontal boundary will be
dropping toward our region, aiding in the initiation of said
showers/storms. Will advertise higher end chance POPs Monday and
Monday night as a result, with temperatures well into the 80s
for Memorial Day.
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
High pressure will be in place over our region through Wednesday
afternoon. Winds will breezy out of the northwest today but will
taper off this evening. Winds will become southerly Wednesday
afternoon through Thursday but remain light. Skies will remain
mostly clear through Wednesday, but clouds will build back into our
region on Thursday with mid to high level cloud decks. VFR
conditions are expected through Thursday but brief restrictions
can`t be ruled out with isolated showers and thunderstorms on
High pressure building to the north Friday and into Saturday
will yield predominate VFR conditions at the terminals.
Afternoon showers/storms will be possible Saturday afternoon,
but much of the activity is likely to remain in the mountains,
with MRB seeing the only potential impact at this time.
Light northerly flow on Friday will veer southerly by Saturday
as the high shifts offshore.
High pressure will be in place over the water through Wednesday
with sub SCA conditions expected. Breezy northerly winds over
18 knots are likely today but winds are expected to taper this
evening. Winds are expected to remain light through Thursday
with winds becoming southerly by Thursday. No further Small
Craft Advisories are expected at this time after today.
Sub SCA conditions expected Friday and Friday night as high
pressure resides north of the waters. Southerly flow increases
on Saturday as the high shifts offshore, but winds look to
remain below SCA criteria through Saturday night at this time.
MARINE...Small Craft Advisory until 6 PM EDT this evening for
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