Weather with Bill Evans
National Weather Service New York NY
Thursday July 11, 2025
A weak cold frontal boundary will slowly push south of Long
Island today into tonight. High pressure then builds in from the
north and east going into this weekend. A warm front approaches
early Sunday, followed by a cold front approaching Sunday night.
High pressure eventually returns early next week, building in
through the middle of next week.
A slow moving cold front boundary pushes farther south through
today. The frontal boundary will also be weakening. Looking
aloft, ridging is taking place as a shortwave and its associated
jet streak move farther northeast of the region. There won`t be
much steering flow.
More sun is expected but extra clouds with convection and some
easterly component to the flow will limit the high temperature
potential. Used a blend of MAVs and NBM, ranging mainly within
the 80s, highest across parts of the interior and NE NJ. Without
much change in dewpoint, heat indices reach a few degrees higher
than the actual temperature. However, they still max out in the
lower 90s range, below advisory criterion.
With the lack of synoptic forcing aloft tonight, would expect
any shower or thunderstorm activity to rapidly diminish this
evening with the loss of diurnal instability. Models are showing
however some increase in shortwave activity late tonight into
early Saturday morning with some increase in upper level winds.
Might have a shower or thunderstorm across parts of the interior
with otherwise a mainly dry night expected.
Light southeast flow at the surface tonight as well as
abundance of clouds will help mitigate radiational cooling. Lows
forecast tonight will only be ranging mainly from upper 60s to
lower 70s. Another round of late night into early morning fog is
forecast, but kept more areas across the interior with coverage
more patchy elsewhere. HRRR indicated this fog development
offshore and moving into the area from the low level southeast
flow.
For the rest of this weekend, with daytime instability each day,
potential for showers and thunderstorms, mainly north and west
of NYC. Airmass remains very warm and humid but looks like heat
indices still expected to remain below advisory thresholds.
A broad mid level trough centered over the Upper Great Lakes
translates east into early next week, helping advance a frontal
system toward and through the region, bringing increased chances
for a more widespread rainfall, especially on Monday ahead of
the cold front. Parameters appear at least marginally supportive
of thunderstorm development, but steering flow appears
progressive enough to mitigate significant flood concerns.
Conditions dry behind the fropa into midweek as weak high pressure
drifts in and NW flow aloft looks to lower the humidity.
Temperatures through the period look to largely stay in the 80s most
afternoons thru early week, with a gradual warm up then into mid
next week.
Not much forcing and absence of a steep pressure gradient keeps
conditions below SCA thresholds on all waters through this
weekend.
Light flow and low seas should then maintain sub Small Craft
Advisory conditions on all coastal waters through early next
week.
Rip current risk is low through Saturday along Atlantic facing
ocean beaches with onshore flow 5-10 kt and a 3 ft swell from
the southeast at a 7-8 sec period.
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