454
FXUS61 KLWX 231015
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
615 AM EDT Fri Oct 23 2026

.WHAT HAS CHANGED...
Several Coastal Flood Advisories were extended/re-issued.
Otherwise, no significant changes to the forecast thinking
overnight, but did add/fine tune the mention of frost the next
couple nights.

&&

.KEY MESSAGES...
- 1) Frost or freezing temperatures are possible in many areas
  tonight and again Saturday night.

- 2) Dry and seasonable conditions are likely to continue
  through much of next week.

&&

.DISCUSSION...
KEY MESSAGE 1...Frost or freezing temperatures are possible in
many areas tonight and again Saturday night.

With a large area of Canadian high pressure building overhead
the next 24 to 48 hours, conditions will likely become favorable
for radiational cooling (light to calm winds, mainly clear skies
and a cool background airmass). The coldest conditions are
expected through early Sunday morning, with some moderation in
temperatures thereafter.

The growing season for 2026 has ended along and west of the Blue
Ridge and Catoctin Mountains, but continues east of there. Any
headlines for frost/freeze conditions will only be issued where
the growing season remains active.

For tonight, temperatures look to fall into the mid 30s for many
areas west of I-95, perhaps even into interior/rural southern MD.
The typically colder spots of northern/north-central MD and the
central VA piedmont could at least briefly come close to freezing.
Will see what the latest guidance and trends have later this
morning before making any headline decisions.

For Saturday night, more widespread cold (possible frost/freeze)
conditions are apparent as high pressure settles more directly
overhead. This would bring the frost/freeze threat for most
areas outside the major urban centers and immediate shore of the
Chesapeake Bay. If the colder temperature guidance verifies,
then the growing season may end for all areas west I-95 come
early Sunday morning.

Relied on a blend of MOS guidance and NBM 10th percentile for
low temperatures the next couple of nights, even undercutting
by a couple degrees in the typically colder locales.


KEY MESSAGE 2...Dry and seasonable conditions are likely to
continue through much of next week.

Sprawling Canadian high pressure will build into the Northeast
and Mid-Atlantic through the weekend as ridging in the upper
levels slowly builds in from the west. Most of the time should
be void of many if any clouds, though some high clouds are
possible as a weakening remnant upper trough pivots and pulls
away through tonight. Thereafter, there are some hints at just
enough saturation in the low levels for perhaps some patchy low
clouds mainly during the early morning hours by later in the
weekend. No precipitation is expected, however.

Heading into early next week, a backdoor front looks to drop
into the region from the north. This will be a dry frontal
passage with not much noticeable change in airmass as it stalls
and weakens over the area. In fact, temperatures may trend
milder early next week as ridging continues to build aloft.

By mid to late next week, there are some hints that upper
ridging begins to break down. Surface high pressure is expected
to hold firm through the forecast period, but there may be a
glimmer of (very) low precipitation chances beyond that point.

With the rather persistently dry airmass in place, the latest
forecast package leans on lower/drier dew point guidance that
has been verifying better of late, especially for the next
couple of days as the pattern remains largely unchanged.

&&

.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
VFR conditions are expected to prevail through early next week.
There are some hints that a slight uptick in low-level moisture
could lead to some patchy fog or low clouds mainly during the
early morning hours by later in the weekend, though confidence
in timing and extent of sub-VFR is low at this time.

N winds with a few gusts to around 15 kts are expected just
after daybreak until roughly 15Z, becoming NE this afternoon.
Winds will be light to calm tonight. A more E flow is likely
Saturday, with light to calm winds again Saturday night. Wind
direction may be a bit variable, ranging from SE to NE as high
pressure passes directly overhead Sunday. Light SE winds early
Monday become NW by midday Monday, then N with a few gusts
possible Tuesday as a backdoor cold front drops through.

It is possible that the first near-freezing temperatures of the
season are observed particularly early Sunday morning for sites
like CHO, IAD and BWI.

&&

.MARINE...
Northerly flow will remain gusty through this morning for most
area waterways (excluding the middle/upper tidal Potomac River).
Winds will gradually subside through the day, likely becoming
sub-SCA across all waters by this evening. Some hi-res guidance
indicates the potential for (1) brief near SCA gusts over the
mid/upper tidal Potomac River around mid morning, and (2) this
evening over the waters around southern MD. However, in both
cases it looks marginal and brief, so no additional advisories
have been issued.

High pressure will build overhead this weekend. Winds will vary
a bit from northeast to southeast, but at light speeds less than
10 knots. Light winds continue Monday as they shift around to
the northwest. An increase in north to northeast flow is likely
in the wake of a backdoor cold front on Tuesday, which may
prompt the next round of Small Craft Advisories.

&&

.TIDES/COASTAL FLOODING...
Generally light but steady northeast winds are expected to keep
water levels elevated through the upcoming weekend. When paired
with high astronomical tides due to the upcoming full moon on
October 26, additional rounds of minor tidal flooding are likely
at vulnerable sites like Annapolis, Straits Point, Dahlgren,
Solomons, and Alexandria. Will have to see if excess water is
able to slowly escape the mouth of the Chesapeake Bay, or if the
northeast flow keeps tides steady or even increases them a bit.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Coastal Flood Advisory until 7 PM EDT this evening for MDZ014.
     Coastal Flood Advisory until 5 PM EDT this afternoon for
     MDZ016>018.
VA...Coastal Flood Advisory until 5 PM EDT this afternoon for
     VAZ057.
     Coastal Flood Advisory until 8 AM EDT this morning for VAZ054.
WV...None.
MARINE...Small Craft Advisory until 11 AM EDT this morning for
     ANZ530>532-538>540.
     Small Craft Advisory until 6 PM EDT this evening for ANZ533-
     534-537-541>543.

&&

$$

DISCUSSION...DHOF
AVIATION...DHOF
MARINE...DHOF
TIDES/COASTAL FLOODING...DHOF

NWS LWX Office Area Forecast Discussion