Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
424 am EDT Friday may 22 2015
a cold front will move across the area today with isolated showers.
In its wake...a cold air mass will filter into the region tonight
into early Saturday morning with frost or freeze conditions. Dry
conditions are expected to prevail through Sunday...with a chance of
rainfall returning by Memorial Day. Temperatures will slowly
moderate over the Holiday weekend.
Near term /until 6 PM this evening/...
as of 415 am EDT...an upper level short wave trough is currently
moving across areas south and east of Albany...with a few light
showers lingering. Any showers will dissipate by 6 am as the
disturbance moves well east of the region. Satellite imagery shows
some clearing west of the Hudson Valley due to subsidence behind
the short wave...although there are additional clouds upstream
along a cold front located over Lake Ontario and the St. Lawrence
Valley at this time.
So there should be a period of clearing this morning for the
southeast 3/4 of the area...with skies averaging partly sunny by
afternoon as the cold front progresses southeastward across the
area. Will mention only isolated showers /slight chance probability of precipitation/ due to
very limited moisture with this system.
Despite cold advection commencing...temperatures will still have
good warming potential due to deep mixing to 700 mb developing from
the Hudson Valley eastward. Highs here will be in the middle 60s to
lower 70s...while cooler middle 50s to lower 60s are expected north and
west. It will be a breezy day...with wind gusts of 25 to 30 miles per hour
common this afternoon once the deeper mixing develops.
Short term /6 PM this evening through Sunday/...
freeze warnings and frost advisories have been issued for late
tonight into early Saturday morning across the region. A cold air
mass will settle in overnight on the back side of an upper level low
moving through New England. It appears the surface high pressure
center will get close enough /central PA/ for winds to eventually
decouple especially after midnight. Most areas outside the Hudson
Valley and Litchfield CT look to have freezing low temperatures in
the upper 20s to lower 30s...with even a few middle 20s possible in the
Adirondacks. For the Hudson Valley and Litchfield CT...frost is
still likely with temperatures dropping to the 33-36 degree range.
After a cold start to the day on Saturday...temperatures will
moderate with abundant sunshine. Below normal readings are still
expected...but with pleasant 60s in the valleys and slightly cooler
upper 50s in the mountains. Saturday night will remain dry...however
winds are expected to be persistent through the night due to more of
a pressure gradient. As a result temperatures should not be as cold
as Friday night with no frost/freeze headlines anticipated at this
time. Sunday looks to feature temperatures warming back into the 70s
in most areas due to a moderating air mass in well mixed
Long term /Sunday night through Thursday/...
00z model runs are in better agreement that the showers
associated with a warm front will start around sunrise on Monday
over western areas... with showers spreading to the rest of the
region during the day. The only model that still shows the
rainfall holding off until Monday night is the Canadian. So as not
to flip the forecast too much...have increased the probability of precipitation during the
day Sunday to between 30 and 50 percent by the afternoon...with
the lowest probability of precipitation over the southeast...highest probability of precipitation over the
northwest. With the warm yet to move through...temperatures Sunday night
and Monday will still be near seasonable levels. Lows Sunday night
will be in the upper 40s to middle 50s. Highs Monday upper 60s to middle
The warm front will lift northeastward through the region Monday
night... followed by Summer like heat and humidity moving into the
region and remaining through Thursday. Highest probability of precipitation are forecast
for Monday night... ranging from around 40 percent over the
southeast...to just under 55 percent over the northwest. Lows
Monday night will be in the middle 50s to lower 60s...and dewpoint
temperatures will slowly rise well into the 50s.
The rest of the long term period will be dominated by a moist
flow of air from the Gulf of Mexico...on the northwest side of a
strong upper level ridge just off the southeast coast. This is the
perfect setup for summerlike heat and humidity...along with a
nearly continuous chance of showers and thunderstorms...especially
each afternoon and evening. Have forecast probability of precipitation generally in the 30
to 40 percent range from Tuesday through Thursday. High temperatures each
day will be in the upper 70s to middle 80s. Lows Tuesday and
Wednesday nights will be in the upper 50s to middle 60s. It will be
humid...with dewpoint temperatures during this period generally in the
low or middle 60s.
Aviation /09z Friday through Tuesday/...
VFR conditions are expected at the kgfl/kalb/kpou/kpsf taf sites
through at least 06z/Sat.
A passing upper level disturbance will bring middle level clouds
overnight along with some sprinkles at kalb/kpou/kpsf where vcsh
has been forecast through about 12z.
A cold front will cross the terminals late Friday morning. A
shower or sprinkle could occur...but again...overall probability
is very low due to lack of low level moisture.
Winds will be light and variable for the rest of tonight. On
Friday...winds will shift into the southwest to west in the morning
and increase to 8-12 knots with some gusts of 15-20 knots. Then...as the
cold front passes...winds will shift into the west to northwest
and increase to 12-18 knots...with gusts reaching 25-30 knots or
slightly stronger Friday afternoon. Winds will begin to slowly
diminish after sunset on Friday.
Saturday night: no operational impact. No sig weather.
Sunday: no operational impact. No sig weather.
Sunday night: no operational impact. No sig weather.
Memorial Day to wednesday: moderate operational impact. Chance of
..low relative humidity values of 20 to 30 percent this afternoon...
..Wind gusts of 25 to 30 miles per hour this afternoon...
A cold front will move across the region today...with dry air and
gusty winds developing this afternoon. Relative humidity values are expected to
drop to between 20 and 30 percent during the afternoon...with west-
northwest winds increasing to 10 to 20 miles per hour with gusts of 25 to 30
miles per hour. So there will be localized fire weather concerns today...but
with trees being in the leafed out/green-up phase...the keetch-Byram
drought index must be considered to ascertain the need for fire
weather headlines. A threshold of greater than 300 is needed...and
currently values are in the 200-250 range so no headlines will be
issued at this time. Despite this...extreme caution should still be
exercised with any outdoor burning.
Relative humidity values will recover somewhat to around 65 to 85 percent
tonight...then drop back down to the 20 to 30 percent range Saturday
afternoon. Northwest winds will become lighter tonight decreasing
to around 5 to 10 miles per hour. Winds on Saturday will be northwest around 10
to 15 miles per hour...with some occasional gusts of 20 to 25 miles per hour. Wetting
rainfall is not anticipated until some time next week.
no Hydro problems expected over the next 5 days...with river levels
holding steady or falling through the period.
Dry conditions will persist through Sunday. A chance for showers and
thunderstorms will return by Monday afternoon into Tuesday...but any
rainfall is much needed due to the recent dry conditions. The U.S.
Drought monitor has now included much of eastern New York and western New
England in the d1 category...which is considered moderate drought.
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
CT...frost advisory from midnight tonight to 8 am EDT Saturday for
New York...freeze warning from midnight tonight to 8 am EDT Saturday for
Frost advisory from midnight tonight to 8 am EDT Saturday for
Massachusetts...freeze warning from midnight tonight to 8 am EDT Saturday for
Vermont...freeze warning from midnight tonight to 8 am EDT Saturday for