813
FXUS61 KLWX 111412
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1012 AM EDT Sun Oct 11 2026
.WHAT HAS CHANGED...
While widespread rainfall amounts of 1 to 2 inches have been
observed, river responses have been limited thus far, likely
owing to ongoing drought conditions. Will continue to monitor
the situation as additional rainfall tracks through the area
this morning. Further, the Storm Prediction Center has now
shifted the Slight Risk near/south of I-64 given a stable east
to northeasterly wind persists over the area.
&&
.KEY MESSAGES...
- 1) Remnants of Isaias bring rain, breezy conditions, and
potential for isolated tornadoes today.
- 2) Above normal temperatures through mid week, then cooler
conditions as moisture starved fronts move through.
&&
.DISCUSSION...
KEY MESSAGE 1...Remnants of Isaias bring rain, breezy conditions,
and potential for isolated tornadoes today.
Rain associated with the remnants of Hurricane Isaias has overspread
the entire region this morning. Given 6 to 12 hours of persistent
moderate intensity rainfall, total precipitation amounts have
largely averaged between 1 to 2 inches. This also includes a few
random pockets of 2 to 3 inches across portions of central
Virginia around the Blue Ridge Mountains. Based on the radar
appearance, this soaking rain is likely to continue through the
remainder of the morning hours. Based on upstream activity, some
of the storms over southwestern Virginia have a bit more
vertical growth to them. Will see how this evolves and
materializes while tracking toward a more stable thermodynamic
environment across the Mid-Atlantic region.
Synoptically not much has changed as the remnant mid-level
circulation of Isaias is now a large cutoff low over the TN Valley.
Forcing for ascent over the Mid-Atlantic is helping maintain
the coverage of rain. The interaction of the cutoff low to the
west and surface high to the east will create a large area of
convergence / broad frontal zone over the Mid-Atlantic. SPC
Mesoanalysis indicates that PWATs of 2" are now pushing
northward into southern Maryland.
Rain totals are generally still around 1.5-2.5" across the area.
Orographic effects of easterly winds into the Blue Ridge will result
in 3-4" of rain along the eastern slopes into the Piedmont. The
Flood Watch in effect for those areas continues. Some of the high
res models indicate the potential for enhanced rainfall over the DC
metro late this evening as a surface wave of low pressure approaches
then slows right around DC, before quickly departing to the east
late tonight. Any additional rain in the metro area could certainly
lead to flooding concerns, so will continue to monitor model and
radar trends to see if the Flood Watch need to be expanded.
In terms of the severe weather threat, SPC has now shifted the
main focus for more intense storms to I-64 and points southward.
This is where the Slight Risk has been shifted which is likely
driven by a stable air mass holding strong off to the north.
Once the main shield of rain departs to the north this afternoon,
most of the area enters a brief lull where we could see some
breaks in the clouds. There`s a better chance for this to occur
over Central VA to Southern MD. A wave of surface low pressure
then tracks through the area this afternoon. If this can take
advantage of any present instability, there is more than enough
shear to fuel organized severe convection. The 12Z IAD sounding
still shows a large cyclonically looping hodograph (0-3 km
storm-relative helicity of almost 800 m2/s2), so the tornado
threat still exists, although cannot rule out a random damaging
wind gust or two. The biggest question mark remains how much
instability can develop, and how far north that instability will
reach. Right now, it appears the most favorable area is going
to be east of the Blue Ridge and south of I-64.
The Wind Advisory remains through late this morning for the
Alleghenies and Blue Ridge where gusts of 45-50 mph are expected.
Elsewhere, breezy conditions develop late this morning into the
afternoon, with the strongest gusts around 20-30 mph.
Another round of steady rain is likely tonight as the cutoff low
aloft moves across the Mid-Atlantic. Precip comes to an end from
west to east Monday morning as the remnants of Isaias finally push
offshore. Humid and warm conditions for Monday afternoon, though
most of the area is going to be dry.
KEY MESSAGE 2...Above normal temperatures through mid week, then
cooler conditions as moisture starved fronts move through.
Brief ridging may bring high temperatures Tuesday and Wednesday
to near 80 degrees. Low pressure passing north of the area will
send a cold front southward sometime on Wednesday. Most of the
rain likely remains across Pennsylvania, although some showers
may sneak southward.
There remains significant model spread the progression of
additional fronts and upper troughs at the end of this week into
next weekend. However, the trend remains for cooler conditions
as highs return closer to normal values for Thursday and
Friday.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
Conditions continue to deteriorate as a steady moderate rain
falls over the region. IFR conditions are expected at all
terminals by late morning, and remain that way through tonight.
It is possible some breaks in the clouds occur this afternoon,
but they build back in this evening. Guidance is indicating the
potential for LIFR CIGs late this evening. Conditions begin to
quickly improve tonight as northwest winds take hold, with VFR
conditions returning Monday morning.
Northwest winds gust around 20-25 knots Monday afternoon, then
diminish Monday night into Tuesday. Prevailing VFR conditions
are anticipated from Tuesday through Thursday. Passing showers
Thursday night into Friday could bring brief sub-VFR conditions.
&&
.MARINE...
SCA conditions expected to continue through tonight as the remnants
of Isaias move across the region. East to southeast wind gusts
to around 30 knots at times throughout the day, with some gusts
to Gale force are possible at times.
Clusters of thunderstorms are likely to move across parts of the
waters this afternoon. It is possible that Special Marine Warnings
may be needed for wind gusts in excess of 35-40 knots and possible
waterspouts, especially for the more southern waters.
Winds over the waters diminish late tonight, but will pick back up
Monday afternoon. Another round of SCAs is going to be needed to
account for these northwest winds. Winds drop again Monday night.
Winds could fluctuate in & out of SCA criteria between Wednesday
and Thursday as a cold front passes through.
&&
.TIDES/COASTAL FLOODING...
Increasing onshore winds and elevated tide levels due to the New
Moon will result in coastal flooding during the high tide this
afternoon to evening. Coastal Flood Advisories have been issued for
some locations, and it is possible additional ones need to be
issued. For Annapolis, while it may be a bit close, the trend
suggests tidal levels fall just short of moderate flood stage.
Thus, a Coastal Flood Advisory is in effect for this evening`s
high tide. Water levels quickly decrease Monday morning as
offshore winds follow.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 11 PM EDT this evening for MDZ008.
Coastal Flood Advisory from 3 PM this afternoon to 11 PM EDT
this evening for MDZ014.
Coastal Flood Advisory from 2 PM this afternoon to 6 PM EDT
this evening for MDZ016.
Coastal Flood Advisory from 1 PM this afternoon to 6 PM EDT
this evening for MDZ018.
Wind Advisory until 11 AM EDT this morning for MDZ509.
VA...Coastal Flood Advisory from 2 PM this afternoon to 6 PM EDT
this evening for VAZ057.
Wind Advisory until 11 AM EDT this morning for VAZ507-508.
Flood Watch through late tonight for VAZ036>040-050-051-501-
502-507-508.
WV...Wind Advisory until 11 AM EDT this morning for WVZ501-505.
MARINE...Small Craft Advisory until 11 PM EDT this evening for
ANZ530>543.
&&
$$
DISCUSSION...BRO/KRR
AVIATION...BRO/KRR
MARINE...BRO/KRR
TIDES/COASTAL FLOODING...BRO/KRR
NWS LWX Office Area Forecast Discussion