Weather with Bill Evans
National Weather Service New York NY
Monday April 1, 2025
High pressure builds across the region through Wednesday. A
warm frontal passage occurs early Thursday. High pressure
briefly builds in from the north on Friday. A frontal boundary
near or over the region will bring unsettled conditions this
weekend. The front should begin moving offshore early next week.
The cold front is well offshore with a tight pressure
gradient over the area as high pressure begins to build toward
the region. Northwest gusts continue to peak near 30kt with a
few localized gusts over 30kts across Long Island. Expect the
deep mixing and pressure gradient to remain through at least
the early afternoon before relaxing somewhat. Highs still on
track for the low to mid 50s areawide, despite the gusty
northwest flow making things feel several degrees cooler.
High pres ridges into the area tngt, with the center of the high
strengthening over QC. Any significant mid clouds are modeled to
not reach the cwa until close to 12Z. Despite the weak pres grad,
this should help winds decouple for most areas overnight. As a
result, went with a blend of the MOS for low temps, which was colder
than the NBM.
Return flow sets up on Wed with thickening mid and high clouds. With
the cool airmass reinforced by the llvl flow off the Atlc, highs in
the 40s per the NBM seemed reasonable.
Llvl moisture continues to increase Wed ngt ahead of an approaching
warm front. As the theta-e ridge builds in, chances for shwrs to
develop overnight, particularly late per the 00Z model timing. At
the same time, stratus and fog are likely to develop with the
advecting marine layer.
The warm front lifts or jumps thru the cwa on Thu. Another 20-plus
degree difference from W to E again as about 200-220 degree llvl
flow develops. E cstl areas could get quite breezy with the synoptic
flow enhanced by the differential heating component. Sustained winds
around 20kt with gusts around 30 possible. With the jet over Canada
and the sfc boundary N of the cwa, a completely dry aftn is possible
and the fcst pops reflect this.
The upper level pattern will consist of mean troughing over the
western CONUS with a strong ridge over the southeast and Western
Atlantic. The region will lie between these features with a series
of mid level shortwaves and associated pieces of energy passing
through into the weekend. The ridge looks to weaken late in the
weekend and especially early next week as the mean upper trough
settles over the eastern seaboard.
The first low pressure will be moving across southeastern Canada
Thursday night helping to drag a cold front across the area. Showers
are possible with the passage of the front Thursday night. Rainfall
amounts on average should be a few hundredths to a few tenths. The
front then sags south on Friday as high pressure briefly builds down
from southern Canada. The high then retreats Friday night into
Saturday as the aforementioned frontal boundary begins approaching
as a warm front. The warm advection and energetic middle level flow
will support the likelihood of showers on Saturday. There may be some
weak waves along the front, which may continue the potential showers
into Saturday night. The modeling then diverges with the placement
of the warm front on Sunday. There is a chance the boundary lifts
over or just north of the area. It is also possible the boundary
stalls near or just south of Long Island. This results in greater
uncertainty with temperatures and degree of instability, if any, for
Sunday. The boundary lifting north could lead to an increase in
instability for a portion of the area and a chance for a few
thunderstorms. The boundary remaining south would likely limit
instability and any thunderstorm potential. For now have continue to
show a chance of showers through Sunday. Another wave of low
pressure may also form to our southwest at some point Sunday into
Sunday night and then pass over or near the area Sunday night. The
low should be able to drag the boundary offshore to start next week
with potential for improving conditions. The latest NBM probably
for greater than 1 inch of rain in any 24 hour period this weekend
is low and generally 10 percent or less.
A sca remains in effect for all waters today with peak gusts
nearing 30-35 kts this morning. The ocean stays at sca lvls
tngt, then all waters stay blw sca lvls for most of Wed. Winds
and waves quickly build Wed eve, with a sca likely needed on the
ocean Wed ngt thru Thu. Winds may be close to criteria
elsewhere on Thu.
Winds on the waters will remain below SCA levels Thursday night
through Saturday. Seas on the ocean will likely be 5-7ft Thursday
night, but should begin subsiding Friday morning with seas below 5
ft late Friday through Saturday.
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