Scientific Forecaster Discussion
fxus61 kaly 271741
Area forecast discussion
National Weather Service Albany New York
141 PM EDT Thu Jul 27 2017
a cold front will bring some showers and thunderstorms to the
area today. Dry weather is expected for most of the area Friday
into the weekend; however, some rainfall is possible across far
southern areas as low pressure passes by to the south.
Temperatures will remain a bit cooler than normal.
Near term /through tonight/...
as of 130 PM, cloud cover abounds throughout the forecast area
with showers over areas south of the Adirondacks. This activity
is occurring in advance of a surface cold front/upper trough
that is readily seen on water vapor imagery. A few breaks in the
clouds are noted over the southern tier west of Elmira. These
breaks in the clouds could make it into the far southern part of
our forecast area this afternoon. Prospects for thunder are
still not very high, but if cloud breaks occur and we
destabilize somewhat, could still see some thunder especially
over the Mid- Hudson valley and northwest Connecticut. Have
lowered high temps a bit more given the persistent cloud cover
over most areas. Some partial clearing could start working into
the southern Adirondacks this afternoon as well. Have shifted
pops southward late this afternoon into the evening as the
front tracks through in concert with hi-res models.
Lingering showers and isolated thunderstorms will remain
possible early tonight as a secondary boundary drops into the
region. Drier air quickly builds in tonight on northwest flow
as high pressure begins to nose in. Can't rule out some fog if
clearing develops, especially in areas that see rainfall
this afternoon. Lows in the upper 50s in the high terrain to the
mid 60s in the valley locations.
Short term /Friday through Friday night/...
Friday, a vigorous, compact upper low will move from the
western Great Lakes towards the mid-Atlantic coast. A seasonably
strong surface low will develop ahead of this feature in the
Lee of the mid-Atlantic Appalachians Friday night. As this
system takes shape, some showers could squeeze into southern New
York Friday night. However, most of Friday looks dry and
seasonably cool with high pressure in place. Highs on Friday
will generally be in the 70s.
Long term /Saturday through Wednesday/...
for this weekend, rather tranquil for most of the region. However,
some subtle changes and trends are possible south of Albany as
latest NCEP model suite and international global guidance suggest
the tail end of the departing trough becomes cut-off from the
westerlies and develops an upper low over the mid-Atlantic region
for the start of the weekend. While this overall trend was further
south, now there are signals of a little further north with the
placement of this low and the slower departure through the weekend
(and perhaps into Monday as well). Ensemble trends also favor a
little northward trend as well so we will take the pops/wx a little
northward with this forecast package through Monday. Overall
confidence is lower than normal through Monday.
Conditions should improve along with warming temperatures through
Tuesday and Wednesday as ridge axis builds across the eastern Continental U.S..
with an increase in temperatures and the approach of another
boundary across the Great Lakes region, the low level moisture
should also increase and the slight chance for some diurnally driven
Temperatures through the period will average near normal through the
Aviation /18z Thursday through Tuesday/...
band of showers continues to slowly advance southward with flight
conditions remaining in the VFR category but bordering MVFR
thresholds. Expectations are for at least the ceilings to drop
back to MVFR through the day as these showers continue to
advance southward and moisten up the lower levels. Kgfl will be
the first to see flight condition restrictions with kpou
experiencing it last.
Then with daytime heating additional isolated to scattered
convection is expected. As with convection, difficult to
highlight the best timing for impacting tafs as we will place a
vcsh with a combination of MVFR to some IFR for kpsf with
favorable upslope conditions and moist lower levels.
Winds will generally be light and variable with a tendency to
become westerly through the daylight hours at speeds 10kts or
less. Then winds become light and variable again tonight. Along
with those light winds the chance of low stratus or fog
formation becomes increasingly probable.
Friday night: no operational impact. No sig weather.
Saturday: no operational impact. No sig weather.
Saturday night: no operational impact. No sig weather.
Sunday: no operational impact. No sig weather.
Sunday night: no operational impact. No sig weather.
Monday: no operational impact. No sig weather.
Monday night: no operational impact. No sig weather.
Tuesday: low operational impact. Slight chance of rain showers...tsra.
showers and thunderstorms will become likely once again
today, especially north of the Mid-Hudson valley. Drier weather
takes hold Friday into the weekend, although periods of
rainfall may impact areas south of the capital district Friday
and Friday night. Temperatures will come up short of normal
values. Relative humidity values will bottom out in the 55 to 65 percent range
Friday, and become drier Saturday in the 40 to 50 percent range.
Northerly winds may become a bit gusty Saturday to near 25 mph.
periods of showers and thunderstorms are expected today into early
tonight. Basin average rainfall is expected to remain below a
half inch; however, locally heavy rainfall will be possible in
any thunderstorm. Isolated urban and poor- drainage flooding
cannot be ruled out in areas that see repeated rounds of
Conditions will generally be dry Friday into the weekend, but
some periods of rainfall may impact areas south of the capital
district Friday afternoon into Friday night. Latest indications
are that amounts will remain on the light side; however, there
is a low probability that the associated storm track will shift
north and bring more of a soaking rain to southern portions of
the forecast area.
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.