Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Binghamton New York
751 PM EDT Sat Apr 25 2015
upper level low pressure over the Canadian Maritimes will keep the
weather unseasonably cool through early next week. Skies will be
mostly clear tonight... then cloudier on Sunday as some moisture
rotates around the upper low and advances toward our region from
the north. The chance of showers will increase Sunday night and
Monday as the upper low moves slightly to the southwest closer to
Near term /until 6 am Sunday morning/...
lots of sunshine continues across the area late this afternoon
with scattered cumulus over the western Catskills... and some high clouds
brushing across northeast PA. A more extensive area of cloudiness
over central and northern New England is rotating southwestward
toward central New York but appears to be eroding as it moves
closer to the area. Expect any cumulus to dissipate early this evening
while high clouds over PA continue to shift south... setting the
stage for a mostly clear night tonight. With a dry airmass in
place and light north-northwesterly flow this will result in
unseasonably cool conditions with lows falling into the 20s at
many locations... with lower to middle 30s in normally warmer
Short term /6 am Sunday morning through Tuesday/...
moisture rotating around the upper low over the Canadian Maritimes
will produce more in the way of SC cloudiness across our area on
Sunday as a weak warm air advection pattern becomes established
over Quebec southward toward New York and Atlantic moisture starts
to be pulled westward. Have gone with low chance probability of precipitation for the western
Catskills and Mohawk Valley with this pattern for Sunday
afternoon but most areas should remain dry. The deep layer airmass
will be slightly warmer Sunday compared to today... but with more
clouds expect temperatures to be pretty similar to today with
highs near 50 in most places.
The upper low backs slightly westward later Sunday night and
Monday increasing the chance of clouds and showers across the
entire area as weak warm advection and moist Atlantic trajectories
continue. Have increased probability of precipitation to high chance or low likely for all
areas by Monday afternoon. Once again temperatures will be on the
cool side with plenty of clouds. Models are in good agreement
showing the upper low moving slightly east on Tuesday in response
to a system moving southeast toward the western Great Lakes. That
should result in some improvement on Tuesday with more sunshine
and temperatures climbing into the 50s to lower 60s.
Long term /Tuesday night through Saturday/...
typical Spring pattern in the long term with slow moving closed lows as
the northern stream jet continues to transition from winter to Summer.
Significant dfrncs in details between the GFS and Euro in the long
term despite a gnrl agreement on the long WV pattern. Both try to build
an upper ridge from the northern plains to the southeast US CST next week. Biggest
dfrnc is that the GFS tries to keep a deep trough over the western
Atlantic that occasionally spins some wet weather through the forecast area. Euro is
drier and keeps closed lows moving independently over the Atlantic
without develops a long WV trough. Believe the Euro makes more sense
given the time of year and the GFS tendency to build dramtic troughs.
So...for the period gnrly kept dry and uneventful weather...with just some
low chance or slight chance at times...especially near the end of the period.
Temperatures will continue a bit below normal in the northerly flow...but higher than
they have been of late.
Aviation /00z Sunday through Thursday/...
conditions remain VFR through tonight under mainly clear skies for
most areas. The exception will be for krme where clouds will
likely persist but conditions will remain VFR.
For Sunday, a broken deck of clouds develops by late morning into
the afternoon as moisture around an upper low retrogrades back
into the area. However at this point indications are conditions
will, at worst, be low end VFR with this deck through the taf
Winds light and variable tonight will become north/northwest at around 5 to
10 knots for Sunday.
Sun ngt-Mon...possible MVFR ceilings at times due to the cool northerly flow.
Tuesday - Thursday...mainly VFR.