Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
1226 am EDT Wednesday Jul 27 2016
high pressure building into the region from the
Great Lakes will allow for a mostly clear sky tonight. Plenty of
sunshine is expected on Wednesday with continued hot temperatures.
Temperatures will continue to be rather warm through the remainder
of the week with the chance for showers and thunderstorms returning
for Thursday into the weekend.
Near term /until 6 am this morning/...
as of 1220 am EDT...mostly clear conditions are expected
overnight with some patchy fog expected. Temperatures remained on
the mild side with readings in the 60s to mid 70s.
Prev disc...at 500 hpa, a large and expansive ridge is situated
over much of the Continental U.S.. our region is located on the northern
fringe of this upper level ridging, with broad W-NW flow aloft
over the area. A weak upper level shortwave sliding along in the
flow is now well downstream of the area over Atlantic Canada.
Meanwhile, surface high pressure situated over the Great Lakes is
expanding northeast towards our area.
Cold air advection in the wake of the departing shortwave trough
allowed for plenty of stratocu/cu today, especially over the high
terrain. However, as high pressure builds into the area,
subsidence and the loss of daytime heating will help these clouds
to dissipate this evening, allowing for mostly clear skies
Clear skies and light winds will allow for good radiational
cooling. With some low-level moisture remaining in place, areas of
fog and mist may develop late tonight in the usual favored
Overnight lows will be seasonable, generally in the upper 50s to
Short term /6 am this morning through Thursday night/...
dry and quiet weather will continue on Wednesday with surface high
pressure nearby. Sky cover will generally be mostly to partly
sunny. With 850 hpa temps around +18 to +19 degrees c, it will
continue to be very warm with highs well into the 80s. A few
spots in the capital region and Mid-Hudson valley may even top
out in the lower 90s. Humidity levels won't be too high for late
July with dewpoints in the upper 50s to lower 60s.
It will remain fairly quiet into Wed night, although there may be
a few more passing clouds from time to time. Lows look to be in
By Thursday, a weak upper level disturbance will be sliding by to
the north across Canada. Although dynamics and large scale
forcing will be limited, there could be some showers or T-storms
around, mainly for areas north and west of the capital region.
Instability will be fairly meager, as warm temps aloft will keep
cape values limited to about 500 j/kg or less for most areas
throughout the day. Model soundings suggest 0-6 km bulk shear is
only around 25 kts as well. As a result, severe weather is not
anticipated, as any T-storms would be fairly brief and pulse in
nature. Highs look to reach the upper 80s to low 90s for valley
areas, with low to mid 80s for the hills and mountains.
On Thursday night, the diurnally-forced showers and thunderstorms
will end in the evening. However, there should could be a few
showers or thunderstorms around later in the night, especially for
southern areas, as a disturbance starts to approach from the Ohio
Valley and mid-Atlantic region. It will be muggy with overnight
lows in the mid to upper 60s for most areas.
Long term /Friday through Tuesday/...
a low confidence forecast shaping up for the long term, as there
continues to be quite a bit of variability among the various sources
of model guidance from Friday through the upcoming weekend.
The period starts out Friday with a potential low pressure system
somewhere in vicinity of the mid Atlantic states, tracking
northeastward close to southern New England Friday night. There
continues to be considerable spread among model guidance, with the
GFS showing the farthest south track, the NAM/CMC farthest north,
and the European model (ecmwf) in between. The gefs mean has a track similar to the
European model (ecmwf). Also, models are indicating possible convective feedback in
quantitative precipitation forecast field, which further complicate where/when actual precip will
occur. For now, will continue to mention chance pops with the higher
values across the southern half of the area closer to the low.
There may be a break in the showery conditions for Saturday, as the
first wave of low pressure departs, but isolated to widely scattered
showers cannot be ruled out. More unsettled conditions are possible
on Sunday, as a potential short wave moves through the mean trough
positioned across the Great Lakes into the northeast. Again, will
mention chance pops due to model differences. Temperatures look to
be seasonable for late July through the weekend, with only isolated
thunder at this time due to limited instability forecast.
It appears drier weather is in store for early next week as high
pressure attempts to build eastward across the region. A few
lingering showers will be possible on Monday as the flow will still
be slightly cyclonic, with a weak disturbance or two moving through.
More in the way of sunshine is expected by Tuesday as the ridge
should have more of an influence by then.
Aviation /06z Wednesday through Sunday/...
few-sct diurnal cu in VFR range moving over the terminals this
this evening. Skies will clear tonight with high pressure moving
in from the west. However, once winds become calm radiation fog
with IFR/MVFR conditions appear likely at kgfl/kpsf starting
around 07z or 08z. Some possible MVFR in br expected at kpou late
tonight. Vcfg at kalb with some fog developing nearby over the
Mohawk/Hudson rivers. Any fog will dissipate by 12z Wednesday with
full sunshine and VFR conditions returning.
Winds will be light and variable to calm overnight and will
remain light into Wednesday morning. Trends toward a westerly
direction through the daylight hours Wednesday.
Wednesday night: no operational impact. No sig weather.
Thursday through Friday night: moderate operational impact.
Chance of rain showers...tsra.
Saturday: low operational impact. Slight chance of rain showers...tsra.
Saturday night through sunday: moderate operational impact.
Chance of rain showers...tsra.
it will continue to be rain-free through at least Wednesday night.
Some showers and thunderstorms are possible as early as Thursday,
although a better chance looks to be Friday into the weekend.
Rh values will be near 100 percent tonight with light to calm
winds. Relative humidity values will drop 35 to 45 percent on Wednesday with west
winds around 5 mph. Relative humidity values will return back to 85 to 95 percent
on Wed night with light to calm winds. Relative humidity values will once again
drop to 35 to 55 percent on Thursday with light and variable winds,
with the lowest values in southeastern parts of the area.
much of the region is currently running 3 to 8 inches below normal
on annual rainfall. According to the U.S. Drought monitor, much of
the area is considered abnormally dry, and parts of the Catskills
and western New England are within a moderate drought.
High pressure will continue to allow for dry weather tonight
through tomorrow night. On Thursday, there is a slight to low
chance for showers and thunderstorms, with the best chance for
areas north and west of the capital region. Any rainfall would be
rather light and sparse in coverage.
A more widespread rainfall is possible between Friday and the
weekend, although model guidance has been unclear on the exact
timing, amounts and duration of the rain. This rainfall is much
needed, as river and stream flows are below normal across much of
eastern New York and western New England.
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.
number of 90+ degree days so far this year through July 25th,
what is normal and the most that has occurred in a year.
2016: 9 days
normal: 10 days
most: 32 days in 1955
note: daily records date back to 1874
Glens Falls ny:
2016: 8 days
normal: 6 days
most: 22 days in 1988
note: records date back to 1949
2016: 17 days
normal: 15 days
most: 30 days (numerous years most recent 2010, 2005 and 2002)
most in july: 17 days back in 1955 (so far this year we have had
12 days with 3 more 90+ days in the forecast this month)
Note: records date back to 1949, however data is missing from
January 1993 through July 2000
2016: 1 day
normal: 2 days
most: 7 days in 2010
based on data dating back to 2000
2016: 2 days
normal: 3 days
most: 9 days in 2010
based on data dating back to 2000