Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
129 am EDT Wednesday Sep 17 2014
dry conditions are expected into the weekend as high pressure
dominates. A cold airmass will move into the region Thursday
setting the stage for areas of frost along with some freezing
temperatures late Thursday night into Friday morning. Temperatures
are expected to rebound to above normal by Sunday ahead of an
approaching low pressure system.
Near term /until 6 am this morning/...
mainly clear skies across the region with 11u-3.9u satellite
imagery does reveal some lower stratus/fog developing in isolated
spots. Expectations are for the remainder of the overnight those
dewpoint depressions will narrow even further...especially near
bodies of water...for patchy fog to develop. Overnight lows look
good with no enhancements needed at this time.
Short term /6 am this morning through Friday/...
cold night on tap for Thursday night into Friday morning with
areas of frost and freezing temperatures expected.
The surface ridging over the region will weaken Wednesday and
Wednesday night. The upper level trough will deepen over the
region as short wave energy rotates about the upper low near
Hudson Bay. This will help push a cold front southward across the
region Thursday and Thursday night opening the door to colder air.
Mainly only an increase in clouds is expected...have only slight
chance probability of precipitation mentioned with the front mainly across the northern
portion of the forecast area. Cold Canadian high pressure will
build in behind this boundary passing over the region Friday with
heights rising aloft.
850 mb temperatures are anticipated to drop to -2 to 3 degrees
celsius across the forecast area by Friday morning. We will need
frost and likely freeze headlines. Have continued to highlight
threat is our hazardous weather outlook with freezing temperatures
possible for southern Adirondacks including the Lake George
area...the central and southeastern Catskills and the higher
terrain of southern Vermont...and frost for rest of the forecast
area except the immediate capital district...middle Hudson Valley and
southern Litchfield County.
Below normal temperatures continue with each day a bot cooler than
the one before. Looking at highs around 10 degrees below normal
generally ranging from the middle 50s to middle 60s.
Long term /Friday night through Tuesday/...
a dry start is in store during this period...but showers become a
threat going into the work week. High pressure slides off the
coast...giving way to low pressure which will track from about Lake
Superior northeast across southern Quebec through Monday. A
southerly flow out ahead of its cold front will bring a rapid
increase in dewpoints and humidity over the weekend...although
temperatures will be increasingly mild and pleasant.
At the temperature peak...highs on Sunday will range mainly from the
upper 60s through the upper 70s. The weekend nights will be much
milder as well. Friday nights lows will be in only the middle 30s to
middle 40s range. By Sunday night...however...they will range from
around 50 degrees in the high peaks of the Adirondacks and
greens...to around 60 degrees down the Hudson Valley...around a 15
degree rebound overall.
When the cold front comes through from the northwest Sunday night...
temperatures dive back to around the seasonably cool levels of the
past 24 hours. Very low convective available potential energy throughout the period means there are
no concerns for convective activity...except perhaps at the very
onset of showery activity Sunday...mainly confined to the Adirondack
region and western Mohawk Valley...where slightly greater
instability is expected. Dry weather returns for Tuesday with
increasing...though not necessarily abundant...sunshine.
Aviation /06z Wednesday through Sunday/...
high pressure will build in from the west overnight through
The combination of mainly clear skies...light winds...and a fairly
moist boundary layer should promote fog/low stratus development
through daybreak...especially between 08z-13z/Wed. The probability for
fog/low stratus and IFR/LIFR conditions is lowest at kalb...where
a light west wind is persisting. This light west wind may keep
most of the fog just east of terminal. Therefore did not include
mention of IFR/LIFR conditions. Have included IFR/LIFR conditions
with fog/low ceilings elsewhere.
Any fog/stratus should lift between 12z-13z/Wed...giving way to
VFR conditions for the rest of Wednesday into Wednesday evening. Some
patchy ground fog may develop once again after 03z/Thu...especially at
Winds will initially be from the west/SW at less than 6 knots...trending
toward calm by daybreak. Mainly west to southwest winds will
resume by middle morning Wednesday at 5-10 knots...becoming light/variable
once again toward and after sunset.
Wednesday night: no operational impact. No sig weather.
Thu: low operational impact. Slight chance of rain showers.
Thursday night-Sat night: no operational impact. No sig weather.
Sun: low operational impact. Slight chance rain showers...tsra.
dry conditions are expected into the weekend as high pressure dominates.
Relative humidity values are expected to recover to near 100 percent
tonight and Wednesday night. Minimum relative humidity values are
expected to be mainly in the 40s Wednesday afternoon. Minimum
values Thursday afternoon are expected to be mainly in the 45 to
55 percent range...with lower values around 40 percent across the
middle Hudson Valley and northwestern Connecticut.
no widespread Hydro problems are expected this week. Dry conditions
are expected into the weekend as high pressure dominates.
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.