Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
225 PM EDT sun Sep 21 2014
the last official weekend of Summer will end on a mild note. A
cold front will move across the region this afternoon and evening
bringing some showers and perhaps a thunderstorm to the area. Cooler
and brisk conditions in the wake of the frontal passage will return
for late tonight into Monday. Looking further ahead...most of next
week looks dry...with seasonable temperatures during the middle of
the week...then above normal temperatures later in the week.
Near term /through tonight/...
the local area is located between a coastal low located off the
middle Atlantic coast and a cold front/low approaching from the west.
The coastal low will move northeastward passing south of Long
Island while the cold front gradually eastward today as the low
moves along the boundary along the New York/Canadian border. The cold
front will move across the area this evening.
The coverage of expected precipitation across the area continues
to be a challenge. The best chance for showers will be across the
northwest portion of the forecast area...to the north and west of
the capital district. While to the south and east chances will be
the lowest. There is still the threat for thunderstorms this
afternoon into the early evening hours. The Storm Prediction
Center continues to have see text across the region with US in the
day 1 convective wind outlook. They did pull the area out of the
hail outlook. Guidance indicates MUCAPE in the middle hundreds j/kg
this afternoon into the evening. The greatest 0-6km bulk shear
will be across the northwest portion of the forecast area with
lesser values as you head to the southeast. There is ongong
convection occurring across the eastern Great Lakes and western
and central New York. Slowed timing of convection across forecast
Warming up nicely as the stratus clouds have lifted and burn off
across most of the forecast area. They do linger across the far
southeast but are lifting. Its also feels humid/muggy as dew
points have risen into 60s across much of the area. Minor adjustments
Short term /Monday through Tuesday/...
the cold front will track across our western New England counties
this evening with the continue threat for scattered-broken line of
convection. In the wake of this frontal passage...the colder Upper Pool with
the trough and the that last wave move across the region
overnight. This will keep the clouds and threat for some showers
which the better probabilities will be across the higher terrain.
Furthermore...lake enhancement from Lake Ontario will also assist
with deeper low level moisture as Delta T/S climb above 13c.
Monday is shaping up to be a rather brisk and cool day with clouds
and the chance for more showers. The Heart of the cold pool /aoa
0c h850/ will be overhead coinciding with a tight surface pressure
gradient to provide gusts over 20kts. Highs Monday will be almost
15 degrees cooler than Sunday/S with mainly 50s across the
terrain and middle-upper 60s for valley locations.
The low level stratus may linger across portions of the region
Monday night with locations downwind of the Catskills likely
experiencing clearing skies including eastern Windham County of
southern Vermont. With the loss the sunlight...showers too should
diminish with overnight lows dipping back to the middle-upper 30s for
the dacks and 40s elsewhere /a reminder that the growing season
has ended across northern Herkimer...Hamilton...northern Warren
Tuesday...model trends are favoring another weak frontal boundary
migrating across the region. Frontolysis will be underway as the
thermal column will be warming through the day along with high
pressure building as heights rise aloft. So there will be
diurnally driven clouds through the day...mainly north and west of
the middle Hudson Valley...as high temperatures achieve 65-70f for valley
locations and low-middle 60s for the terrain.
Long term /Tuesday night through Saturday/...
ridging at 500 hpa will be in place for the entire extended
period...with building heights through the entire week. The 00z gefs
shows 500 hpa height anomalies of 1-2 Standard above normal by late in
the week...with anomalies of 2-3 Standard above normal situated just to
our northwest...where the core of where the warmest heights will be
At the surface...a large strong sprawling area of high pressure will
control the weather through the entire week as well. The high will
slowly move from over upstate New York and New England on Wednesday to off
the coast for Thursday through Saturday. This high pressure allow will
allow for dry conditions with mostly clear skies. Temperatures will
gradually warm up throughout the week...with valley highs in the
upper 60s to near 70 on Wednesday...low 70s on Thursday...and middle 70s for
Friday and Saturday. With the clear skies and light winds...good
radiational cooling will occur each night...and lows will generally
be in the 40s to low 50s /some upper 30s over the high terrain/.
Most areas that still have the growing season ongoing look to avoid
a frost/freeze through the upcoming week.
Aviation /18z Sunday through Thursday/...
lower clouds associated with the coastal low continue to impact the
southeast portion of the forecast area...kpou and kpsf...along with
some weak/light showers. Clouds are advancing into the northwest
portion of the forecast area ahead of the approaching cold front and
low. While inbetween clouds cover has been rather minimal at kgfl
Mainly VFR conditions will continue...however MVFR conditions will
linger a bit longer this afternoon at kpou. Clouds will be in the
increase and are expected to lower this evening and tonight
especially in the wake of the cold front with MVFR conditions
There are a couple lines of showers occurring ahead of the front
across western and central New York into Pennsylvania. Theses lines
will move eastward...however they are expected to weaken so have
address threat with vcsh in tafs.
Southerly flow will continue to gusty especially up the Hudson River
valley this afternoon. The winds will weaken this evening then shift
to the west with the passage of cold front tonight. Once daytime
mixing starts the westerly winds will become gusty.
Monday through Thu: no operational impact. No sig weather.
low level moisture will be high across the region with the
increase probability for showers...so expect relative humidity values to remain
above 50 percent through Monday night. We dry out Tuesday as we
begin a prolonged period of dry weather.
Southerly winds of 5 to 15 miles per hour with some gusts over 20 miles per hour today.
Winds shift to the west-northwest tonight then increase in gust
magnitudes on Monday well over 20 miles per hour at times.
no widespread Hydro problems are expected through next week.
A low pressure system will approach and cross the region today
bringing some much needed rainfall to the area Sunday into Sunday
night. Rainfall amounts are anticipated to generally be a tenth to a
third of an inch with higher amounts of 1/2 to 1 inch across
A return to dry weather is expected for most of the upcoming week.
For details on specific area rivers and lakes...including observed
and forecast river stages and lake elevations...please visit the
advanced hydrologic prediction service /ahps/ graphs on our website.