Catonsville, Maryland 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

354
FXUS61 KLWX 081800
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
200 PM EDT Tue Apr 8 2025

.SYNOPSIS...
A strong area of high pressure will build in through the middle
of the week. An upper-level system will bring additional rain
to the area Thursday into Friday. High pressure will return
over the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
A few leftover cumulus clouds will dissipate heading into this
evening as high pressure and dry air build overhead. The cold
and dry airmass coupled with light winds and clear skies tonight
will lead to ideal radiational cooling conditions. Low temps
tonight will be 15 to 25 degrees below normal, perhaps near
record levels in spots (see Climate section).

The well below normal temps equate to lows in the 20s for most
of the area (around freezing in the urban cores and perhaps mid
to upper teens in the coldest spots). Have gone ahead and
started the growing season early and issued Freeze Warnings in
coordination with surrounding offices. This is due to recent
warmth and the fact we are only a few days from the typical
start of the growing season for areas near and east of I-81
(excluding the Blue Ridge Mountains).

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As high pressure builds overhead and eventually pushes offshore
on Wednesday, a brief return to quiet weather is expected.
Highs return to the mid 50s Wednesday afternoon under mostly
sunny skies as winds switch back out of the south.

The upper-level pattern will become more amplified toward the end of
the week. The initial shortwave and associated low pressure system
will approach on Thursday. Rain chances will increase Thursday as
the warm front lifts into the area. This of course will also
come with an increase in temperatures back to the upper 50s to
low 60s for areas along and south of the front. However, highs
north of the front remain in the upper 40s to low 50s.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
There continues to be discrepancies in the models regarding the
possible cutoff low pressure system late in the week into the
first half of the weekend.

The NAM model `tendency` and the GFS model both show a cutoff
low pressure system developing Friday night and then pivoting
across New Jersey and south of Long Island Saturday into
Saturday night. Dry conditions would be more likely along and
west of I-81, while moderate rain tapers and gradually ends from
west to east through the day Friday into Friday evening.
Saturday and Saturday night would be dry, cooler and breezy.

The EURO and Canadian models both show a cutoff low pressure
system developing slowly over our CWA Friday into Friday night
and not moving a lot to the northeast or east Saturday into
Saturday night. Therefore, this scenario of either model would
reveal moderate rain much of the day Friday and Friday night.
Moderate rain would linger early Saturday before transitioning
over to scattered showers on the backside of the low later
Saturday into Saturday night. The only difference is that the
EURO is more generous toward heavier rainfall amounts in any one
area than the Canadian.

For now, the solution we have in terms of the cutoff low
pressure system Friday through Saturday night is moderate to
heavy rain showers everywhere Friday through Friday evening.
Showers linger Friday night into Saturday morning, before
becoming isolated Saturday afternoon, then ending southwest to
northeast Saturday night.

High temperatures both Friday and Saturday are expected to be below
average with highs mainly in the 50s with some 40s in the mountains
and lower 60s near the Chesapeake Bay shoreline. Low temperatures
will be mainly in the 30s in the mountains and in the 40s
elsewhere both nights.

As for Sunday into Monday, high pressure will build into the region
from the west and bring tranquil conditions Sunday, with warmer
conditions Monday. High temperatures will mainly be in the 50s
Sunday, then warming into the upper 60s to lower 70s on Monday.

Along with the warmer temperatures on Monday comes a chance for
showers to reenter the picture late Monday into Monday evening,
mainly in the mountains with the next approaching low pressure
system.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
High pressure building in will lead to diminishing winds and
clear skies tonight. It will be cold, with well below freezing
temperatures expected early Wednesday morning. High pressure
persists through Wednesday, which should keep winds light
(shifting to S) and conditions VFR. Southerly winds may gust to
around 20 kt Thursday. Sub-VFR conditions due to low ceilings
and rain are possible late Thursday.

Widespread rain shower coverage could induce IFR or LIFR conditions
at the terminals Friday through Saturday night. There are
discrepancies since we are 3 and 4 days out from the possible cut-
off low. Coverage and intensity are still uncertain based on
the multiple model solutions, but something to keep in mind.
Winds east becoming northeast 5 to 10 knots Friday and Friday
night, becoming north to northwest 5 to 10 knots Saturday and
Saturday night.

&&

.MARINE...
Tonight is a great setup for northerly channeling of winds
along the open waters of the Chesapeake Bay. An SCA was issued
for this threat into Wednesday morning. High pressure returns
by Wednesday, with sub-SCA conditions expected at this time.

SCA conditions are possible again Thursday into Thursday night
with southerly flow developing ahead of an approaching frontal
system, which will bring unsettled conditions by Thursday night.

Small Craft Advisories are possible late Friday into Friday
evening, then again Saturday afternoon into Saturday evening.
This will be determined by the position and intensification of
a possible cutoff/coastal low pressure system late in the week
into the weekend. Winds southeast becoming northeast around 10
knots gusts up to 20 knots Friday and Friday night. Winds
northeast becoming northwest 10 knots gusts up to 20 knots
Saturday and Saturday night.

&&

.CLIMATE...
Well below normal temperatures are expected tonight through
Wednesday morning, dropping 15 to 25 degrees below normal.

Below is a list of record daily low temperatures for April 9.

Site                                    Record (year set)
Washington DC area              (DCA)   28 F (1972, 1917, 1896)
Baltimore MD area               (BWI)   26 F (2007)
Baltimore Downtown MD area      (DMH)   28 F (1972)
Sterling-Dulles Airport VA area (IAD)   23 F (1977)
Annapolis MD area               (NAK)   23 F (1972)
Hagerstown MD area              (HGR)   21 F (1972)
Martinsburg WV area             (MRB)   20 F (1972)
Charlottesville VA area         (CHO)   26 F (2007)

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Freeze Warning from 2 AM to 9 AM EDT Wednesday for DCZ001.
MD...Freeze Warning from 2 AM to 9 AM EDT Wednesday for MDZ003>006-
     008-011-013-014-016>018-503>508.
VA...Freeze Warning from 2 AM to 9 AM EDT Wednesday for VAZ025>031-
     036>040-050-051-053>057-501-502-505-506-526-527.
WV...Freeze Warning from 2 AM to 9 AM EDT Wednesday for WVZ051>053.
MARINE...Small Craft Advisory until 6 AM EDT Wednesday for ANZ530>534-
     537>543.
     Small Craft Advisory until 7 PM EDT this evening for ANZ535-
     536.

&&

$$

SYNOPSIS...DHOF/CJL
NEAR TERM...DHOF
SHORT TERM...DHOF/CJL
LONG TERM...KLW
AVIATION...KLW/DHOF/CJL
MARINE...KLW/DHOF/CJL
CLIMATE...DHOF