Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Albany New York
642 am EDT Thursday Aug 28 2014

Synopsis...
high pressure will continue to build in from the central
Great Lakes region into the northeast today. It will move over New
York and New England on Friday with fair and dry weather to close
the week. The surface high will move offshore Friday night into
Saturday with a return southerly flow of more humid air to open the
Holiday weekend.

&&

Near term /until 6 PM this evening/...
as of 642 am EDT...pleasant and dry late August weather conditions are
expected today with an upper level trough slowly shifting
downstream over New York and New England...as surface high pressure ridges
in from the central Great Lakes region and southern Ontario. Strong
subsidence in the wake of the cold front...and with the surface
anticyclone building will promote partly to mostly sunny
conditions with temperatures near or slightly below normal. The cloud
over the western Mohawk Valley...eastern Catskills...Taconics...srn
greens...Berkshires...and Litchfield Hill should dissipate quickly
this morning.

H850 temperatures will range from +7c to +11c from northwest to southeast over eastern New York
and western New England with cold advection ongoing this morning. Deep
mixing and the surface pressure gradient between the approaching surface
anticyclone and the departing Cristobal over the western Atlantic will
keep it breezy today with northwest winds 10 to 15 miles per hour with a few gusts
around 25 miles per hour over the eastern Catskills...capital region...Mohawk
Valley...and Berkshires.

High temperatures were favored closer to the cooler gfsmos values with
middle and u70s in the valleys...and m60s to l70s over the hill towns
and mountains humidity levels will be very comfortable.

&&

Short term /6 PM this evening through Saturday night/...
tonight...the winds should diminish shortly after sunset with the surface
high building in over New York and western New England. The skies will clear
and ideal raditional cooling conditions will set up. Patchy fog is
likely in the major river valleys. Lows will be on the chilly side
with 40s to l50s. Some u30s are possible in the Adirondacks of
Hamilton County.

Friday...more great late August weather with mostly sunny
conditions with low humidity levels. Surface dewpoints will be in the
u40s to l50s. The surface high should be centered over eastern New York and New
England during the day...which will limit deep mixing. Maximum temperatures
will be similar to Thursday...but with less wind. High temperatures will range
from the u60s to m70s over the region with a few u70s in the middle
Hudson Valley...and northwest CT.

Friday night...the surface high moves off the New England coast towards
the Gulf of Maine and Nova Scotia. Initially temperatures will drop off
with clear skies and light to calm winds...but some cirrus should
begin to move in from the south and west after midnight. A warm
front will start to lift north from the Ohio Valley and the Upper
Middle Atlantic region. Lows will not be not as cool as the previous
night with widespread 50s.

Sat-Sat night...more clouds then sunshine is possible on
Saturday...especially north and west of the capital region. A warm
advection regime sets up with an increasing S/SW flow in the low
to middle levels may cause isolated to scattered showers to develop over the
southern dacks...western Mohawk Valley...and eastern Catskills during the late
morning into the afternoon. Any isolated thunderstorms would be tied
to the diurnal heating. It will start to become more humid...but
based on the latest GFS/ECMWF/gefs...and even NAM trends most of
this day appears to be dry with the best synoptic forcing well
north and west of the area. Highs in the u70s to l80s are expected
on the first third of the Labor Day Holiday.

During the evening...the low and middle level ridge becomes firmly
established over the eastern Seaboard. A weak perturbation in the SW
h500 flow...and ahead of the frontal boundary north of the St
Lawrence River valley may focus some isolated-scattered showers...and
perhaps some isolated thunderstorms from the capital district...southern
Vermont...eastern Catskills north and west. It will be muggy with lows
generally in the 60s.

&&

Long term /Sunday through Wednesday/...
unsettled weather will be the norm during much of the long term
period from Sunday through Wednesday. Forecast area looks to be impacted by
several frontal boundaries which are expected to produce at least
scattered convection Sunday through Tuesday with drier weather by
Wednesday.

On Sunday expect a low pressure system to move along a cold front
dropping slowly southward from the upper Great Lakes and southern
Canada. This boundary is expected to remain across southern Canada into
Monday with a trough of low pressure extending southward through our
region. Late Monday night into Tuesday a cold front will be
approaching the eastern Great Lakes which will move through our area
by Wednesday morning bringing more showers and thunderstorms to our
region. High pressure will then finally build east from the Ohio
Valley resulting in improving conditions on Wednesday. Precipitable waters will
generally be between 1.5 and 2.0 inches for much of the time Sunday
through Tuesday...so not only will it be humid...but there is the
potential for some heavy rainfall as well Sunday through Tuesday.

Temperatures are expected to average above normal with precipitation
expected to be well above normal during the long term period. Highs
are generally expected to be in the middle 70s to middle 80s Sunday and
Monday and in the upper 70s to upper 80s on Tuesday...Wednesday will
be cooler with highs in the upper 60s to lower 80s. Lows will mainly
be in the 60s Sunday night and Monday night and in the middle 50s to
middle 60s Tuesday night.

&&

Aviation /12z Thursday through Monday/...
mainly VFR conditions are expected at the taf sites through the
taf period ending at 12z Friday. The exception will be at kgfl where
LIFR fog is expected for a time later tonight after 08z and at kpsf
where MVFR conditions are expected after 08z tonight.

During the day today...VFR conditions will be prevalent with
generally p6sm sct040-060 conds. West-northwest winds will increase during daytime
to around 10 kts then decrease this evening with sky clear conditions after
00z.

Outlook...

Friday night to saturday: no operational impact. No sig weather.
Saturday night: low operational impact. Slight chance of rain showers...tsra.
Sunday: moderate operational impact. Chance of rain showers...tsra. Sunday
night: moderate operational impact. Chance of rain showers...tsra. Labor
day: moderate operational impact. Chance of rain showers...tsra. Monday
night: low operational impact. Slight chance of rain showers. Tuesday:
moderate operational impact. Chance of rain showers...tsra.

&&

Fire weather...
high pressure will continue to build in from the central
Great Lakes region into the northeast today. It will move over New
York and New England on Friday with fair and dry weather to close
the week with less humid conditions.

Relative humidity values will lower to 35 to 50 percent this
afternoon...then increase 90 to 100 percent Friday morning with a
very heavy dew formation. The relative humidity values will fall to 30 to 50
percent Friday afternoon

The winds will increase from the northwest at 10 to 15 miles per hour today
with some gusts in the 20 to 25 miles per hour range. The winds will become
light to calm Thursday night...and be light and variable in
direction at 5 miles per hour or less on Friday.

&&

Hydrology...
no widespread Hydro problems are expected on the main Stem rivers
the next 5 days ending Labor Day.

Another stretch of dry weather is then expected today into
Saturday morning...as high pressure returns to the region and then
moves offshore to start the weekend. The main Stem rivers will
continue to slowly recede into Saturday.

A slow moving cold front near the St Lawrence River valley will
focus scattered showers and thunderstorms Sunday into Monday in a
much more humid air mass. The threat for locally heavy rainfall
with any thunderstorms will increase by Labor Day.

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...wasula
near term...wasula
short term...wasula
long term...11
aviation...11
fire weather...jpv/wasula
hydrology...jpv/wasula

National Weather Service Glossary of Abbreviations