Cheltenham, Maryland Weather Forecast Discussion

578
FXUS61 KLWX 020120
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
920 PM EDT Wed Oct 1 2025
.SYNOPSIS...
Broad high pressure over eastern Canada will wedge south into the
region through Friday bringing lower humidity and cooler
temperatures. The wedging high will gradually push off the New
England coast leading to moderating temperatures this weekend.
The next chance for rain arrives with a cold front early next
week.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
00Z IAD sounding shows dry air throughout the column. No
changes needed to the forecast. Probably too dry for fog besides
some mist along the rivers. Current dew points in the mid 30s
in Garrett County support the previously issued Frost Advisory.
Main concern will be for tidal flooding (see section below).
Previous discussion:
High pressure over Quebec will gradually build southward over
the next few days, eventually settling over New Jersey by Friday
morning. This will support fair weather conditions and north to
northeast winds around 10 mph or less. Low temperatures tonight
will fall into the 40s west of I-95 with even some mid 30s and
frost in the most sheltered high elevation valleys.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
The surface wind flow will turn more onshore Thursday into
Friday leading to a scattered stratocumulus deck. Lows Friday
morning will be similar to Thursday despite more clouds around.
The surface high will drop further down the Mid-Atlantic coast
with light winds and daytime stratocumulus clouds Friday. It
will continue to be cooler than normal, especially at night due
to good radiational cooling conditions under high pressure.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Persistent upper-level ridging will remain over the East Coast
Saturday through early next week as troughing approaches from
the west. At the surface, high pressure stationed over the
Northeast will yield reduced cloud cover and dry conditions
Saturday through Monday. High temperatures will warm gradually
with highs in the 70s to low 80s for most; those at higher
elevations will stay in 60s each day. Overnight low temperatures
will be in 40s and 50s Saturday night before warming to the 50s
and 60s Sunday night.
As upper-level troughing approaches the area, a cold front
will approach from the Great Lakes early next week. This will
bring the next chance for precipitation Tuesday into Wednesday.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
N/NE winds AOB 10 kt are expected through through tonight. Flow
will become E to SE Thursday, then SE Friday. Few to scattered stratocumulus
clouds may develop Thursday morning and persist on and off
through Friday with bases between FL025-FL060 (lowest 09z-16z).
Winds remain out of the south Saturday and Sunday, blowing 5 to 10
knots each afternoon. Winds are expected to become light and
variable overnight. VFR conditions persist both days with no
precipitation in the forecast.
&&
.MARINE...
Winds will gradually diminish and turn from N/NE to E then SE
through Friday. SCAs may be cancelled early if the gradient
relaxes a bit quicker than anticipated. There is some potential
for the wider waters of the bay to see renewed advisory
conditions Thursday night. Otherwise, light winds and dry
weather are forecast through the end of the week.
Southerly winds of 5 to 10 knots are expected across the waters
Saturday and Sunday. No marine hazards are expected as high
pressure builds over the waters.
&&
.TIDES/COASTAL FLOODING...
The threat for widespread minor coastal flooding, with moderate
coastal flooding at Annapolis, will occur during multiple high
tide cycles through Friday. Anomalies are climbing faster than
previously forecast, and will likely top out near or above 2
feet above normal for many locations. Have expanded advisories
to most of the other tidal zones. Warning remains in effect for
Anne Arundel for tonight only (though Thursday night could also
be close). The daytime high tide is astronomically lower, then
water levels may start declining somewhat after that. However,
advisories will likely need to be extended for some locations
for the Thursday night cycle if not into Friday. Water levels
should equalize toward the end of the week as the tropical
systems move farther offshore.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Coastal Flood Advisory until 7 AM EDT Thursday for MDZ011.
     Coastal Flood Warning until 5 AM EDT Thursday for MDZ014.
     Coastal Flood Advisory from 5 AM to 5 PM EDT Thursday for
     MDZ014.
     Coastal Flood Advisory until 3 PM EDT Thursday for MDZ016-018.
     Coastal Flood Advisory until 1 PM EDT Thursday for MDZ017.
     Coastal Flood Advisory from 3 AM to 10 AM EDT Thursday for
     MDZ508.
     Frost Advisory from 2 AM to 9 AM EDT Thursday for MDZ509-510.
VA...Coastal Flood Advisory until 3 PM EDT Thursday for VAZ057.
     Frost Advisory from 2 AM to 9 AM EDT Thursday for VAZ503-504.
WV...Frost Advisory from 2 AM to 9 AM EDT Thursday for WVZ501-503-
     505-506.
MARINE...Small Craft Advisory until midnight EDT tonight for ANZ531-532-
     540-542.
     Small Craft Advisory until 6 PM EDT Thursday for ANZ533-534-
     537-541-543.
&&
$$
SYNOPSIS...DHOF/EST
NEAR TERM...ADS/LFR/DHOF
SHORT TERM...LFR/DHOF
LONG TERM...AVS
AVIATION...ADS/AVS/LFR/DHOF
MARINE...ADS/AVS/LFR/DHOF
TIDES/COASTAL FLOODING...ADS

NWS LWX Office Area Forecast Discussion