Area forecast discussion
National Weather Service Albany New York
525 PM EDT sun may 19 2013
Synopsis...
an approaching weak warm front will produce showers into early
across areas from Albany north and east. Warmer temperatures will
return to the region for much of the upcoming week...along with
several opportunities for showers and thunderstorms.
&&
Near term /until 6 am Monday/...
as of 445 PM...current radar trends the showers over the northeast
half of the forecast area gradually shifting eastward and out of the
forecast area. However...a large batch of showers was also sliding
southeast across the Saint Lawrence valley and far northern
Adirondacks. This batch will likely affect the Albany adirodack
zones as well this evening and then slide southeast across the upper
Hudson Valley and eventually southern Vermont. Will continue likely
probability of precipitation in these areas into this evening. Probability of precipitation will be forecast to
decrease in all areas tonight...droping to slight chance in all
areas by 06z. It will remain cloudy with temperatures not droping that much
from there current readings. Lows will generally be in the low or
middle 50s.
&&
Short term /Monday through Tuesday night/...
as low pressure moves across southern Canada...a trailing cold
front will slide south into the region on Monday and then become
stationary across the region through Tuesday. During Tuesday night
this boundary will begin to slowly lift northward as a warm front as
another wave of low pressure moves east through the northern Great
Lakes.
This will all result in a unsettled weather patter with lows of
clouds and periods with showers and possible thunderstorms. Timing of these
systems will be difficult...but it would appear that Tuesday afternoon
into Tuesday night will be the period with the best chance for
widespread shower activity. Have forecast a 30 to 40 percent chance
of showers Monday afternoon and evening...and a 40 to 50 percent chance of
showers Tuesday afternoon and night. As instabiltity increases...will
also be including a chance of thunderstorms Monday afternoon and evening...and
again from Tuesday afternoon through Tuesday night.
It will be warmer during the short term period. Highs Monday will be
in the 70s. Lows Monday night in the 50s to lower 60s. Highs Tuesday
in the 70s to around 80... lows Tuesday night in the middle 50s to
lower 60s.
&&
Long term /Wednesday through Sunday/...
the model and ensemble guidance are in fairly good agreement
weakening closed low over the Midwest as it heads northeastward
and shears out as moves across the Great Lakes region into the
northeastern United States as the ridge over the eastern United
States flattens. An upper low will drop southward from near Hudson
Bay across eastern Canada as we head into weekend.
At the surface...the low pressure system will move eastward and
across the northeastern United States late in the week. The
system's warm frontal boundary will have moved into the region by
middle week and the area should be in the warm sector for Thursday. The
system's cold front is expected to move across the region Thursday
night/Friday morning. The atmosphere will be unstable as boundaries
move through so have thunderstorms in the forecast for Wednesday
through Thursday night. The upper trough axis will still need to
swing through Friday. For the weekend...ridging is expected to build
southward out of Canada at the surface while aloft the models are
not quite in agreement about how long it will take before heights
begin to rise...looks like we may have to be wait until Monday.
As for temperatures...looking at above normal for Wednesday and
especially on Thursday. However...with the passage of the cold front
and the upper trough moving over region it will be cool with below
normal temperatures through much of the weekend. Expecting highs
mainly in the 60s with chilly nights with lows in the 40s with 30s
across the higher terrain.
Note: the growing season has already started across the middle Hudson
Valley...greater capital district...Lake George Saratoga
region...the Mohawk Valley...eastern Catskills...Taconics...
Bennington County...Berkshires and Litchfield County. It will start
on may 20th for eastern Windham County and on may 25th on the
southern Adirondacks and western Windham County.
&&
Aviation /18z Sunday through Friday/...
MVFR/IFR ceilings and visibilities will continue to provide dismal
flying conditions through the taf period as scattered showers and
overnight fog develop in an increasingly moist low-level airmass.
This afternoon...scattered shower activity will continue to impact
all taf sites occasionally dropping ceilings and visibilities to IFR
levels. Have indicated tempo groups to account for uncertainty
regarding shower coverage/timing. In between these showers all taf
sites will remain primarily at MVFR levels as abundant low-level
moisture and a low stratus deck remain entrenched across the region.
Tonight into Monday...shower coverage will begin to diminish this
evening...however cannot rule out an isolated shower affecting the
taf sites through the remainder of the taf period. Light winds and
saturated low-levels will allow for IFR fog/low stratus development
towards daybreak at all taf sites. Flying conditions should improve
to VFR after 12z Monday...with vcsh persisting.
Southerly winds will be generally around 5-10 knots this afternoon
with occasional gusts to 20 knots where the flow can be channeled.
Winds will diminish to near calm overnight before increasing
slightly to around 4-8 knots Monday.
Outlook...
Monday night-Fri...VFR/MVFR. Chance -shras/-tsras.
&&
Fire weather...
relative humidity values will rise to near 100 percent tonight as rain showers end
this evening. As a humid airmass moves into the region on Monday...
relative humidity values will remain above 50 percent.
Winds will be southerly through tonight at 5 to 15 miles per hour...then shift
to southwest on Monday at the same speed...but with some gusts to 20
miles per hour.
&&
Hydrology...
occasional light rain that has fallen over the northeast two-thirds
of the forecast area will likely result in a tenth to a quarter of
an inch before it ends this evening. This amount of rain will have
little impact on area streams and rivers.
There will be a continued threat for showers and possibly
thunderstorms during much of the week. Due to the scattered nature
of the showers...basin average quantitative precipitation forecast will be highly variable this
week. The best threat for seeing significant amounts of showers or
thunderstorms will be during the middle to late week period.
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...gjm
near term...gjm
short term...gjm
long term...iaa
aviation...irl
fire weather...gjm
hydrology...gjm
