Good Day on This Tuesday October 20, 2020
An upper level disturbance will move across today. Otherwise,
offshore high pressure will prevent a weak cold front from
moving into the area until late Wednesday night and Thursday
morning. The front will stall nearby or just south of the area
on Thursday as high pressure passes to the north Thursday into
Friday. Another cold front will approach on Saturday, and pass
through on Sunday.
Area of showers and isolated tstms approaching from the south
should impact mainly Long Island and southern CT this morning
per latest guidance. Hi-res guidance indicated additional bands
of showers developing and moving across during the morning and
early afternoon, with a stripe of rainfall of 1/4 to 1/2 inch
across central/eastern Long Island and SE CT.
Otherwise, clouds and onshore flow will prevail today. Despite
the cloud cover and precip, temps should reach the lower 70s in
the NYC metro and the upper 60s elsewhere.
For tonight and early Wed morning, low level moisture will
remain locked in place as a moist onshore flow continues. Patchy
light rain/drizzle/fog should spread in from the east mainly
after midnight. Low temps will range from the lower 60s in/just
outside NYC, to the mid/upper 50s elsewhere. cloud cover will
begin to thin out in the afternoon, with a mild day expected as
high temps reach the lower and mid 70s.
Models in fairly good agreement with the region remaining under the
influence of western Atlantic ridging later this week, as
longwave troughing dominates the north Central portions of the
country. The ridging weakens this weekend as an energetic
shortwave slides through southern Ontario and Quebec Friday into
Saturday allowing the eastern flank of the upper trough to push
overhead with a fast cross-CONUS SW flow aloft. This upper flow
will also help deflect Hurricane Epsilon NE away from the coast
heading into this weekend, eventually shearing into this flow
east of the Canadian Maritimes.
A weak cold front will sags through the region Wed Night/Thu AM,
with Canadian high pressure gradually building into New
England Thu into Fri. Low clouds and patchy drizzle may be
possible mainly for coastal areas Wed night, before passage of
this front. A transition in air mass from warm and moist Wed/Wed
night to warm and drier Thu with offshore flow and more
sunshine. Temps on Thu could be nearly 10 degrees above
seasonable for this time of year. A transition to a Canadian
maritime airmass on Friday, with gusty NE flow between high
pressure sliding off the Canadian maritimes and Epsilon making
its closest approach as it attains hurricane strength. Long
period energetic swells from Epsilon will be building to the
shoreline as well Thu night into Friday, lingering through the
weekend.
The next chance of showers looks to be late Saturday into
Sunday as a stronger cold front sags into the region. This front
and associated showers activity could linger near the area into
early next week depending on how deeply the longwave trough
amplifies across the western US and the resultant orientation of
upper flow over the area. Low predictability at this time on
frontal position, but general agreement that the brunt of an
expansive cold pool over Canada remains locked near the
Canadian/US border for the time being, with near seasonably
temps in the wake of the frontal passage.
.MARINE...
A cold front slowly approaches the waters today and eventually
stalls well to the north and west of the waters tonight with that
same front lifting back north by Wednesday. Another cold front
approaches Wednesday night and moves across early Thursday. Overall,
the pressure gradient will remain weak through Wednesday night with
a slight increase in the pressure gradient on Thursday.
Conditions on all forecast waters are expected to remain below SCA
thresholds through Wednesday night. SCA level seas getting up to
near 5 ft are forecast for the ocean Thursday. Wavewatch shows some
long period swell emanating away from Epsilon and getting into
the local waters on Thursday. That is why despite winds being
relatively light, wave heights from the Wavewatch are rising to
near 5 ft by Thursday afternoon.
Good Day on This Tuesday October 20, 2020
An upper level disturbance will move across today. Otherwise,
offshore high pressure will prevent a weak cold front from
moving into the area until late Wednesday night and Thursday
morning. The front will stall nearby or just south of the area
on Thursday as high pressure passes to the north Thursday into
Friday. Another cold front will approach on Saturday, and pass
through on Sunday.
Area of showers and isolated tstms approaching from the south
should impact mainly Long Island and southern CT this morning
per latest guidance. Hi-res guidance indicated additional bands
of showers developing and moving across during the morning and
early afternoon, with a stripe of rainfall of 1/4 to 1/2 inch
across central/eastern Long Island and SE CT.
Otherwise, clouds and onshore flow will prevail today. Despite
the cloud cover and precip, temps should reach the lower 70s in
the NYC metro and the upper 60s elsewhere.
For tonight and early Wed morning, low level moisture will
remain locked in place as a moist onshore flow continues. Patchy
light rain/drizzle/fog should spread in from the east mainly
after midnight. Low temps will range from the lower 60s in/just
outside NYC, to the mid/upper 50s elsewhere. cloud cover will
begin to thin out in the afternoon, with a mild day expected as
high temps reach the lower and mid 70s.
Models in fairly good agreement with the region remaining under the
influence of western Atlantic ridging later this week, as
longwave troughing dominates the north Central portions of the
country. The ridging weakens this weekend as an energetic
shortwave slides through southern Ontario and Quebec Friday into
Saturday allowing the eastern flank of the upper trough to push
overhead with a fast cross-CONUS SW flow aloft. This upper flow
will also help deflect Hurricane Epsilon NE away from the coast
heading into this weekend, eventually shearing into this flow
east of the Canadian Maritimes.
A weak cold front will sags through the region Wed Night/Thu AM,
with Canadian high pressure gradually building into New
England Thu into Fri. Low clouds and patchy drizzle may be
possible mainly for coastal areas Wed night, before passage of
this front. A transition in air mass from warm and moist Wed/Wed
night to warm and drier Thu with offshore flow and more
sunshine. Temps on Thu could be nearly 10 degrees above
seasonable for this time of year. A transition to a Canadian
maritime airmass on Friday, with gusty NE flow between high
pressure sliding off the Canadian maritimes and Epsilon making
its closest approach as it attains hurricane strength. Long
period energetic swells from Epsilon will be building to the
shoreline as well Thu night into Friday, lingering through the
weekend.
The next chance of showers looks to be late Saturday into
Sunday as a stronger cold front sags into the region. This front
and associated showers activity could linger near the area into
early next week depending on how deeply the longwave trough
amplifies across the western US and the resultant orientation of
upper flow over the area. Low predictability at this time on
frontal position, but general agreement that the brunt of an
expansive cold pool over Canada remains locked near the
Canadian/US border for the time being, with near seasonably
temps in the wake of the frontal passage.
.MARINE...
A cold front slowly approaches the waters today and eventually
stalls well to the north and west of the waters tonight with that
same front lifting back north by Wednesday. Another cold front
approaches Wednesday night and moves across early Thursday. Overall,
the pressure gradient will remain weak through Wednesday night with
a slight increase in the pressure gradient on Thursday.
Conditions on all forecast waters are expected to remain below SCA
thresholds through Wednesday night. SCA level seas getting up to
near 5 ft are forecast for the ocean Thursday. Wavewatch shows some
long period swell emanating away from Epsilon and getting into
the local waters on Thursday. That is why despite winds being
relatively light, wave heights from the Wavewatch are rising to
near 5 ft by Thursday afternoon.
