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Area forecast discussion
National Weather Service Buffalo New York
324 am EDT Sat Sep 21 2019

high pressure centered along the Carolina coastline will continue to
provide US with pleasant late Summer weather and well above normal
temperatures through Sunday. The next chance of widespread rain will
arrive Sunday night and Monday as a cold front moves through the
eastern Great Lakes.


Near term /through tonight/...
high pressure remains centered along the Caroline coast and for the
most part will remain in control of our weather. Increasing
southwest flow on the back side of the high will help bring in a bit
more moisture today. Forecast soundings showing a bit more
instability developing during peak afternoon heating. The
instability combined with the increasing moisture will help to
develop more diurnal cumulus, with some more robust cumulus
possible along the Lake Erie lake breeze, where a pop-up shower
can not be ruled out. A good surge of warm air will enter the
region today with most areas seeing temperatures getting into
the upper 70s to lower 80s, with even a few mid 80s possible.

Any limited shower activity that develops on the Lake Erie lake
breeze will end early this evening, however higher dewpoints and
warmer temperatures will remain through the night on increased
southwesterly flow.


Short term /Sunday through Monday night/...
Sunday deep southwesterly flow will be found across the region which
will lie between a departing surface high just off the southeast coastline
and frontal trough of low pressure to our northwest. The increasing
pressure gradient will give a warm breeze Sunday afternoon and
overnight across the region. Occasional gusts could reach 35 mph to
the northeast of Lake Erie.

The cold front to our west will slowly edge eastward, possibly
bringing a few showers Sunday night to our western zones, and then
across the entire region Monday as the front passes. The influx of
tropical moisture (pwats near 1.75 inches) and a deep warm cloud
depth could bring brief heavier downpours. The early in the day
passage will limit instability...and will keep thunder out of the

Though some 10 degrees lower Monday, temperatures will still be
above normal with highs in the low to mid 70s.

A surface wave along the cold front is making for a slower exit to
this system...with rain showers likely through at least the first
half of the day Monday as the cold front advances across our
region...and likely rain showers into Monday night east of Lake
Ontario where wrap around moisture and upslope flow continues

It will be cooler, and less humid Monday night with lows dropping
back into the upper 40s to mid 50s across the region.


Long term /Tuesday through Friday/...
a sharp mid level trough and surface low will exit off the New
England coast Tuesday. Wrap around moisture and lingering ascent
from the departing mid level trough may support a few showers
through the first half of the day east of Lake Ontario, with dry
weather across western New York. Wrap around and diurnally driven cloud
cover will be most prevalent east of Lake Ontario, with clearing
skies by evening as deeper moisture moves east of the area.

High pressure will build into the Ohio Valley and eastern Great
Lakes Tuesday night before moving to the East Coast Wednesday. This
will provide a return to dry weather for our region, with patchy
frost possible across the interior north country Wednesday morning. A
cold front will then sweep east across the eastern Great Lakes late
Wednesday night or Thursday. The GFS is faster than the European model (ecmwf) by
about 6 hours. The slower European model (ecmwf) timing is preferred with the best
rain chances during the day Thursday. High pressure is then forecast
to build into the eastern Great Lakes Friday, with a return to dry

The coolest day will be Tuesday as a pool of cold air aloft moves
across the eastern Great Lakes. Expect highs in the upper 60s at
lower elevations, and lower 60s across higher terrain. Temperatures
will then warm into the 70s for the rest of the week.


Aviation /07z Saturday through Wednesday/...
River Valley fog through about 14z with local IFR, but the lower
conditions are expected to remain just east of the kjhw terminal.
Otherwise, high pressure centered over the Carolina coast will
allow for VFR conditions through this evening. There is a
localized threat for a few showers between 19z and 22z along the
Lake Erie lake breeze.


Tonight and Sunday...mainly VFR, with localized IFR in southern
tier valley fog possible late tonight and early Sunday.
Sunday night and Monday...areas of MVFR with showers likely.
Tuesday...MVFR/VFR with scattered showers.


high pressure will provide our region with light winds and minimal
wave action through tonight.

A low pressure system will develop across northern Ontario province
this weekend, with southwest winds increasing to 15 to 25 knots by
Sunday. Small craft advisories may be needed for portions of
the area during this time.


the kbuf WSR-88D radar remains down due to an equipment failure.
Repairs are expected to begin this morning with a return to
service expected by this afternoon.


Buf watches/warnings/advisories...
New York...none.



near term...Fries/jjr/tma
short term...Thomas

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