Area forecast discussion
National Weather Service Albany New York
122 am EDT Monday may 20 2013
Synopsis...
a warm front will lift north of the area on Monday...with warmer
temperatures returning to the region for much of the upcoming
week. Increasing humidity levels will accompany the warmth...along
with several opportunities for showers and thunderstorms.
&&
Near term /until 6 am this morning/...
as of 122 am EDT...the regional radar mosaic shows showers have
ended across our area. Due to little forcing in place...no
additional showers are expected through the remainder of the
overnight hours. However...the abundant low level moisture and
light S-southeast off the Atlantic will keep plenty of low clouds
around...and perhaps some pockets of mist...especially across the higher
terrain. Min temperatures won't drop much from current readings due to
the high relative humidity and low clouds around...with lows in the lower to
middle 50s for most places.
&&
Short term /6 am this morning 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 instability 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 /06z Monday through Friday/...
expecting mainly dry conditions overnight as radar not showing any
showers in the region. However...low level moisture will remain
entrenched across the region tonight as a light southeast marine
flow continues. This will result in widespread overcast skies...in the
IFR range to start at kpou and kpsf...and MVFR at kalb and kgfl.
Ceilings should lower to just below 1000 feet even at kalb and
kgfl after 08z. Ceilings should lift back to MVFR after 12z at all
sites. Some MVFR visibilities are also possible between 07z-12z at
all sites...when ceilings are at their lowest. Ceilings should
slowly rise through the day after 12z and clouds should go to
scattered late in the afternoon...generally after 21z.
Winds will be south southeast less than 5 knots through the
morning...shifting to the south-southwest by midday and west to
southwest at less than 10 knots tomorrow afternoon.
Outlook...
Monday night-Fri...VFR/MVFR. Chance -shra/-tsra. Late night/early
morning IFR possible associated with fog and low stratus clouds.
&&
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/jpv
near term...frugis
short term...gjm
long term...iaa
aviation...NAS
fire weather...gjm
hydrology...gjm
