Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
920 PM EDT Thursday may 28 2015
a cold front will settle south and east of the region overnight...as
high pressure builds in from the Great Lakes. This will bring cooler
and much less humid conditions for tonight...and warm but dry for
Friday. The high will move off the East Coast Friday night...as a
cold front moves southward toward and across the region late
Saturday into Sunday. This should bring showers and thunderstorms to
the region...followed by much cooler temperatures by Sunday.
Near term /until 6 am Friday morning/...
as of 920 PM EDT...in the wake of the cold front...much cooler
and drier air continues to overspread the region.
As high pressure builds across the region overnight...and winds
decrease...we expect skies to be mainly clear...setting the stage
for excellent radiational cooling. We therefore have went a little
below the mav/met MOS...with most temperatures from I-90 north falling
into the middle 40s to lower 50s...with mainly Lower/Middle 50s to the
Short term /6 am Friday morning through Sunday/...
Friday...high pressure will drift across the region bringing sunny
and warm conditions...after an initial cool start. Humidity levels
should remain low...so it should be quite comfortable. Expect maximum
temperatures to reach the Lower/Middle 80s by late afternoon in
valleys...and 70s across higher terrain.
Friday nt...some models suggest showers arrive in northwest areas before
daybreak Sat...while the majority keep conditions dry...with just
some clouds and an increasing south wind. Expect mild temperatures...only
falling into the middle 50s to lower 60s for most areas...perhaps a
bit warmer close to the Hudson River valley.
Sat-sun...models are trending a bit slower with the
approaching/passing front from the north and west...with some suggestion
of a weak wave developing along it. At this time...have indicated
best chance of showers/storms for late Sat...and more so for Sat
nt and early sun...before tapering from north to S later sun. As for
severe potential...most models suggest the timing of the frontal
passage for Sat nt...at time of minimal heating. Also...0-6 km
bulk shear is fairly weak Sat afternoon ahead of the
front...generally in the 20-25 knots range or less. Middle level lapse
rates are also not forecast to be overly impressive...generally in
the 5.5-6 c/km range. The degree of diabatic heating is also in
question Sat afternoon...as middle level clouds may spread across the
region limiting heating...especially for areas north of I-90. At this
time...perhaps the biggest threat during this time could be
locally heavy downpours should any training cells develop late Sat
or Sat nt. Otherwise...maximum temperatures should reach the Lower/Middle 80s
Sat afternoon...perhaps even warmer should more sunshine occur than
currently expected. Sat nt/sun am mins should only fall into the
upper 50s to middle 60s. The trickiest temperatures will be Sunday...as
shallow cold air advection settles southward across the region. If
clouds and especially rain persist...maximum temperatures may be quite
limited...perhaps barely rising out of the upper 50s to lower 60s
for portions of the region. For now...have indicated slightly
warmer maxes...in the 65-70 range in valleys and 60-65 across
higher elevations...in case the rain tapers off and any thin spots
in the clouds develop...or the front slows down a bit allowing for
warmer morning temperatures before frontal passage. However...it is possible that
if the surface boundary passes and rainfall lingers in its
wake...much cooler maxes are possible.
Long term /Sunday night through Thursday/...
this Marks the beginning of a dry period...with high pressure in
control through the period. The only chance of probability of precipitation will be Sunday
night into Monday for mainly the southern zones. Temperatures will
increase daily...with highs anywhere from the upper 50s to lower
70s. By Thursday...highs will range from the middle 70s to middle 80s.
Normal highs at Albany are in the middle 70s. Lows will become only
slightly milder daily...with lows Sunday night ranging from the middle
40s to middle 50s. By Wednesday night...lows will be in the 50s at all
locations. Normal lows at Albany are in the lower to middle 50s.
Aviation /01z Friday through Tuesday/...
the cold front which brought showers and thunderstorms to parts of
the region has now moved southeast of the forecast area. For tonight VFR
conditions are expected...until after 06z-07z when some fog and
low clouds could develop at all taf sites. Too far out to be
specific...so indicating MVFR visibilities with scattered clouds
below 500 feet...but kgfl and kpsf could see broken ceilings
depending on how much low level moisture lingers with the light to
calm winds toward sunrise. By 14z...any MVFR/IFR conditions should
mix out and VFR conditions should return...through the rest of the
Winds should be around 10 knots from the west to northwest with
gusts 15 to 20 knots at times early this evening. Winds diminish to
near calm through the night and remain variable at 6 knots or less
after daybreak and through tomorrow morning.
Friday night: no operational impact. No sig weather.
Saturday: moderate operational impact. Breezy chance of rain showers...tsra.
Saturday night: high operational impact. Breezy likely rain showers...tsra.
Sunday: high operational impact. Likely rain showers.
Sunday night: moderate operational impact. Chance of rain showers.
Monday: no operational impact. No sig weather.
Monday night: no operational impact. No sig weather.
Tuesday: no operational impact. No sig weather.
most areas have received rainfall amts greater than one quarter of
an inch over the past 2 days.
Relative humidity values will recover to 90-100 percent tonight with widespread
dew formation likely. The relative humidity will then fall to 35-45 percent for
Widespread showers and thunderstorms are expected for late Sat
rainfall amts over the past 24-36 hours generally ranged from one
tenth...to one third of an inch. However...locally much higher
amts of 1-2 inches occurred...especially from Schenectady Colorado into central
Saratoga Colorado and southeast Warren/southern Washington cos.
Dry conditions are expected through Friday nt.
A cold front is expected to bring widespread rainfall amts of one
half...to one and one half inches between Sat and sun. Locally
heavy downpours could lead to ponding of water in low lying...poor
drainage and urban areas...especially should any heavier downpours
repeatedly occur in any location.