Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Albany New York
357 PM EDT Wednesday Jun 3 2015

Synopsis...
high pressure over New England will slide offshore on Thursday.
Late Thursday into Friday a weather disturbance along the Carolina
coast will bring some clouds from the Catskills to southwest New
England. A cold front will approaching from the Great Lakes will
move through late Friday into Friday night...bringing scattered
showers and thunderstorms. A large area of high pressure will then
build over the region for the weekend from Ontario with dry and
seasonable conditions.

&&

Near term /until 6 am Thursday morning/...
as of 400 PM EDT...high pressure centered over New England providing
plenty of sunshine and dry conditions late this afternoon. Winds
have been less than 10 miles per hour...and will decrease after sunset. Some
high level clouds will pass through mainly southern areas
tonight...but should not be thick enough to preclude radiational
cooling. So expecting another cool night with lows mainly in the
40s. Patchy fog will also be possible in some spots. The center
of the high will drift towards the Gulf of Maine by sunrise
Thursday.

&&

Short term /6 am Thursday morning through Saturday night/...
high pressure will shift eastward of the coast on Thursday. Models
have backed of on timing of moisture approaching from the Middle
Atlantic States associated with a coastal front and weak upper level
low. So we are expecting sunshine across most of the area for much
of the day...with clouds increasing for southern areas from the
Catskills and middle Hudson Valley eastward to southwest New England
late in the afternoon. High temperatures are expected to be very
close to average...except a few degrees below normal across southern
areas due to clouds moving in late in the day.

A southerly return flow around the departing high will help to
eventually advect moisture/clouds into at least the southern half of
the region Thursday evening and night. This will make for a tricky
temperature forecast depending on where clouds vs. Breaks in the
clouds set up. Will mention the coolest readings across the
Adirondacks with upper 40s...and lower to middle 50s farther south and
east. Will only mention a slight chance of showers late south of
Albany with limited forcing.

There looks to be a better chance of at least scattered showers and
thunderstorms on Friday...as a cold front and upper level
disturbance approach from the Great Lakes. Models indicating modest
low level convergence/forcing along the boundary...with the best
upper dynamics passing by well to our north over Quebec. Instability
parameters look marginal...especially considering clouds may hold
for a while for areas south and east of Albany through much of the
day. Best instability axis looks to be mainly from the capital
district westward...but SBCAPE values are forecast to be rather
limited at generally 500-1000 j/kg or less. The NAM is showing
higher values compared to the GFS...but will depend on degree of
sunshine that occurs. Also 0-6 km shear looks fairly weak around 20-
25 kts so the severe threat is low at this time.

Chances for showers/T-storms continues into the evening hours Friday
as the cold front passes through...but instability should start to
wane after dark. Also moisture looks to be fairly meager so any
convection should dissipate by around midnight. Northerly winds will
develop in wake of the cold front late Friday night with cold
advection commencing.

&&

Long term /Sunday through Wednesday/...
confidence is high in the extended as 1z GFS/Canadian and European
models all indicate a similar scenario in the extended forecast.

The extended period opens with a northwesterly flow aloft bringing
high pressure overhead Saturday night and it lingers into Sunday. At
the surface...high pressure will crest overhead Saturday night and
keep it dry through Sunday.

Temperatures will in the 70s. A cutoff low is forecast by all these
models to lift out to our south Sunday.

Sunday night...high pressure will slide off to our east...and is
forecast to be followed by a fast moving potent upper air low moving
to our north...dragging an occluded front across the region on
Monday. We will continue with chances of showers overnight Sunday
into early Monday...increase chances to 50 percent by Monday.
Despite the fact the latest GFS indicated only meager cape for
Monday...we continue with chance of thunderstorms...mainly for the
afternoon. If we were to get some sunshine...the airmass could
easily become increasingly unstable.

The front GOES by Monday night...but energy from the strong upper
air low over Ontario Canada...could trigger some additional showers
..possibly lingering through Tuesday night. With a cold pool
aloft...there could be some small hail with the showers.

By Tuesday night...high pressure is forecast to build back into the
region from central Canada lingering into Wednesday.

Overall temperatures look seasonable through the extended with highs
generally in the middle to upper 70s in the valleys...middle 60s to lower
70s higher terrain. Lows will will be in the 50s Tuesday
morning...middle 50s to lower 60s Monday night and Tuesday night.

&&

Aviation /20z Wednesday through Monday/...
no aviation weather related problems through midnight as VFR
conditions will predominate.

The sky will be clear to partly cloudy with few-scattered cumulus around 4500
feet and a scattered cirrus. A north wind will average 5-10 miles per hour.

Tonight we loose most if not all wind. The sky will remain mostly
clear. Being such a short night...and some increasing wind aloft
after midnight...might mitigate the formation of fog. We did place
shallow fog (mifg) at all the taf sights except kalb. At
kalb...there might be just enough of a breeze to prevent all fog but
please check back if you plan to fly later overnight or early
Thursday for any updates.

Thursday looks like a good aviation day with a light wind become south-southeast
5-10kts and sky again mainly devoid of clouds.

Outlook...

Thursday night: no operational impact. No sig weather.
Friday: moderate operational impact. Chance of rain showers...tsra.
Friday night: moderate operational impact. Chance of rain showers...tsra.
Saturday to sunday: no operational impact. No sig weather.
Sunday night: moderate operational impact. Chance of rain showers.
Monday: moderate operational impact. Chance of rain showers...tsra.

&&

Fire weather...
high pressure over New England will slide offshore on Thursday.
Late Thursday into Friday a weather disturbance along the Carolina
coast will bring some clouds from the Catskills to southwest New
England. A cold front will approaching from the Great Lakes will
move through late Friday into Friday night...bringing scattered
showers and thunderstorms. A large area of high pressure will then
build over the region for the weekend from Ontario with dry and
seasonable conditions.

Relative humidity values will rise to around 85 to 100 percent
tonight...decreasing to minimum values of between 35 and 45 percent
Thursday afternoon. Relative humidity values will recover to around 80 to 100
percent Thursday night.

Winds tonight will be light and variable...becoming southerly around
5 to 10 miles per hour on Thursday. Winds will continue from the south around 5
miles per hour Thursday night.

&&

Hydrology...
river levels will continue to recede as mainly dry conditions will
dominate through Sunday...other than scattered showers and
thunderstorms Friday afternoon and evening. A more widespread
rainfall with showers and thunderstorms is possible early next
week

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.

&&

Aly watches/warnings/advisories...
CT...none.
New York...none.
Massachusetts...none.
Vermont...none.

&&

$$
Synopsis...Snyder/jpv
near term...jpv
short term...jpv
long term...hwjiv
aviation...hwjiv
fire weather...jpv
hydrology...Snyder/jpv

National Weather Service Glossary of Abbreviations