Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
745 PM EDT Thursday Oct 8 2015
clouds will be increasing this evening as a storm system
approaches from the Great Lakes. An area of rain will spread across
the region late tonight...especially for northern areas...and
continue into tomorrow morning...as low pressure passes by to the
north. Steady rain will transition to rain showers and isolated
thunderstorms for tomorrow afternoon...as the storm/S cold front
passes through the area from west to east...with precipitation
ending by the early evening hours. Dry and seasonable weather is
expected over the weekend...with cool morning temperatures and mild
Near term /until 6 am Friday morning/...
as of 745 PM EDT...clouds were slow to increase across the area just yet
as they were still back across Lake Ontario. They will however...begin to
quickly build into northern areas in the next few hours...then slide further
south as overnight. High pressure continued to retreat further east off
the New England coastline.
For this update...tempered back the cloud coverage the evening hours.
As result of the slow increase in clouds...temperatures have dropped
quite a bit...especially north of the Mohawk River where some
places were already into the upper 40s...while most other places were in the 50s.
We did not lower overnight lows cause once these clouds
begin to make their move...temperatures should halt in their decline.
The timing of the onset of rain looks pretty good although it might be a tad
too fast. For now...made no real changes in the timing of the rain.
Temperatures look to fall this evening...and eventually hold
steady/slowly rise...as cloud cover increases and a southerly
breeze starts to develop. With isentropic lift /warm air
advection/ occurring...a steady rain will be moving into the
region from western and central New York late tonight. By 2 or 3
am...rain will begin first across the Adirondacks and western
Mohawk Valley...and gradually spread east and expanding across the
region. By sunrise Friday morning...rain will likely be occurring
as far south as the Berkshires and capital region...although areas
further south could still remain dry...as the best lift may be
occurring to the north of the Catskills...middle Hudson Valley and
northwest CT. The steadiest/heaviest rain looks to occur across the
Adirondacks...where the core of a 50 knots low level jet will be
pushing into the region...upsloping the high terrain. Some pockets
of moderate to locally heavy rainfall could be possible for these
far northern areas late tonight.
Min temperatures will be occurring in the middle of the night...as the
increasing clouds/southerly flow will allow temperatures to rise for the
last few hours of the night. Mins will mainly be in the middle 40s to
middle 50s...although a few cooler spots are possible across the
Short term /6 am Friday morning through Saturday night/...
with a surface warm front crossing the region...steady rainfall will
continue into Friday morning...especially for areas north of I-90. The
best isentropic lift looks to shifting north of the area by midday
Friday...as surface low pressure passes by to the north across the
northern Adirondacks and into central/northern Vermont. It may not
rain much across far southern areas until the afternoon hours...when
the storm/S cold front will be crossing the area from west to
east. During the afternoon hours...model guidance suggest some surface
based instability could be present for southern parts of the County Warning Area.
The models may be overdoing it somewhat...as cloud cover in place
should prevent much instability from occurring. Still...cannot
rule out a rumble of thunder...so will include isolated threat for
thunder across far southern areas with the passage of the storm/S
cold front on Friday afternoon. Any breaks in the clouds could allow for
more instability and warmer temperatures...so will have to watch
satellite trends closely tomorrow. Temperatures look to range from the
upper 50s to upper 60s across the area...although some low to middle
70s are possible for the middle Hudson Valley...especially if any breaks of
Rain looks to be tapering off on Friday evening with the cold front
crossing the area from west to east. Total quantitative precipitation forecast will only be a
quarter of an inch for far southern areas...around a half to three
quarters of an inch for the capital region and southern Vermont...and an
inch to inch and a quarter across the Adirondacks and Lake
George/Saratoga area. It may be cloudy for the first half of the
night...but clouds should decrease by late Friday night...as the
storm continues to move away...and high pressure over the Great
Lakes starts to build into the area. Min temperatures will be in the
40s...with some upper 30s over the Adirondacks.
With high pressure passing overhead...dry and seasonable weather
is expected for Sat into Sat night. Plenty of sunshine will be in
place on Saturday...with mostly clear skies on Sat night. Cooler
temperatures aloft /850 hpa of only 3 to 6 degrees c/ will only allow
for highs in the 50s to near 60 on Saturday /some 40s for the
Adirondacks and greens/. A cool night is expected for Sat night
with most areas falling into the 30s. Some frost is possible Sat
night for outlying areas where the growing season is still
ongoing...so will mention this threat in the severe weather potential statement statement.
Long term /Sunday through Thursday/...
a rather fast/zonal/progressive flow will be in place across noam as
the latest global model consensus continues to suggest a mild start
to the long term...then a little cool down into the middle week period.
A broad and increasing southerly flow evolves on Sunday as a warm
front continues to lift northeast of the region. A h850 temperatures climb
to above +10c...along with downsloping component...this will result
in a period of above normal temperatures /normal highs are usually
into the lower 60s/. Highs on Sunday and Monday will be 5-10
degrees above normal.
Short wave trough...which is coming ashore across the British
Columbia shoreline...is expected to race along and just north of the
U.S./Canadian border late Monday night into Tuesday. This will
likely be the main period with the potential of wet conditions where
we will place chance-scattered probability of precipitation.
In the wake of the frontal passage...h850 temperatures settle back into the lower
single digits which will result in a more seasonable temperatures
for the middle of October.
Aviation /00z Friday through Tuesday/...
VFR flying conditions will prevail at the taf sites through the
evening ... diminishing to MVFR conditions towards sunrise
and continuing into the afternoon hours. Rain will be associated with
a low pressure system impacting the region.
Per our fogger local study (a new program implemented by one of our
interns ian lee)...most models indicated the formation of IFR fog/low stratus
between 06z-10z at most of our taf sites. However...with an increase
of clouds...the only station we place a brief period of IFR fog/stratus
was kpsf since the clouds will take longer to reach there and it will cool
more than the other stations. We only have it there from 08z-10z.
Otherwise...MVFR condtions (low MVFR at kpsf and kgfl) into the afternoon
hours...improving to VFR at kpou and kalb at 20z and 22z respectively.
The wind tonight will be light or calm...becoming south or southeasterly
5-10kts later overnight into Friday...with some higher gusts possible
at kspf and kalb later on Friday (not included in the taf yet).
The wind will turn more westerly later Friday afternoon as an
occluded front works through the region.
Friday night: low operational impact. Slight chance of rain showers.
Saturday: no operational impact. No sig weather.
Saturday night: no operational impact. No sig weather.
Sunday: no operational impact. No sig weather.
Sunday night: no operational impact. No sig weather.
Columbus day: no operational impact. No sig weather.
Monday night: low operational impact. Slight chance of rain showers.
Tuesday: moderate operational impact. Chance of rain showers.
with a storm system moving across the region...a steady and
wetting rainfall will move into the region tonight and continue
into much of tomorrow. Relative humidity values will be above 60 percent this
entire time. Light winds this evening will become south at 10 to
20 miles per hour by tomorrow morning...and become west at 10 to 15 miles per hour by
late in the day on Friday.
With dry weather returning over the weekend...relative humidity values will fall
to 40 to 50 percent each afternoon. Northwest winds will be 5 to 15 miles per hour on
Saturday...and S-SW at 5 to 10 miles per hour on Sunday.
no Hydro problems are expected through at least the next five days.
It will remain dry through this evening...as high pressure departs
across northern New England. Late tonight into tomorrow morning...a
storm system will bring a steady rain to the region...which will
be tapering to showers on tomorrow afternoon before ending in the
evening hours. The rain will be heaviest for areas north of
Interstate 90. Rainfall amounts will range from just a quarter of
an inch over the middle Hudson Valley and northwest CT...to around an inch
and a quarter over the Adirondacks. This rainfall will cause some
minor rises on rivers and streams...but no flooding will occur.
Behind this storm system...dry weather will return for the
Columbus day weekend...as another high pressure area moves
towards the region. The next chance for rain will be some showers
along a passing cold front on Tuesday.
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