Scientific Forecaster Discussion
fxus61 kaly 191424
Area forecast discussion
National Weather Service Albany New York
924 am EST sun Feb 19 2017
a cold front will pass through the region today with isolated to
scattered rain or snow showers north and west of the capital
region. An upper level disturbance moves through tonight with
high pressure building back into the region behind it. Another
weak mid-level disturbance approaching from the west will bring
chances for light mixed wintry precipitation Tuesday evening
through Tuesday night. Temperatures will generally be above
average this week.
Near term /through tonight/...
as of 920 am EST, weak frontal boundary was progressing through
the region with a stronger push of colder air set to arrive much
later. Cloud coverage was most prevalent south of i90 with the
stratus deck remaining well upstream at the present time. So a
window of opportunity for more sunshine, ample mixing per our
12z sounding, and with favorable locations with respect to
downsloping we will increase our afternoon high temperatures a
couple more degrees. In addition, also delayed the pops a bit
further across the Adirondacks due to aforementioned drier
profiles and delay of the stronger arrival of the cold front.
As of 630 am EST, temperatures continue to fluctuate from the
low 30s to upper 40s across the area. High level clouds have
moved in across the central portion of the forecast area and
this is where the milder temperatures are currently seen. So
very tricky temperature forecast today depending on this
mornings low temperature and variable cloudiness. Have nudged
temperatures towards the latest glamp guidance as it seems to
have somewhat captured the temperature variability across the
region this morning.
Latest WV imagery shows a strong mid level jet oriented west to
east across New York, sandwiched between a disturbance to our
north and a strong upper low moving into the Carolinas. This
disturbance, and surface cold front, will drop through the area
late today into tonight with noticeable cooling behind the
front. Low level clouds are also expected to increase throughout
the day but are still well north of the area, per latest infrared
imagery. Depending on how slow the low level clouds advance
southward today will determine how warm the temperatures can
climb this afternoon. Current thinking is that temps will climb
into the lower 40s in the high terrain and potentially into the
mid 50s in the Mid-Hudson valley, especially since early
morning temperatures remain fairly mild overall. So have went
above guidance for afternoon highs. Most locations will remain
dry with the passage of the disturbance except for a slight
chance for rain/snow showers north and west of the capital
district late this afternoon into the overnight period.
As winds turn out of the north/northwest, strong cold advection
will ensue allowing temperatures to dip into the low 20s to low
30s overnight tonight.
Short term /Monday through Tuesday/...
any lingering shower activity should be gone by dawn on Monday.
Clouds will then gradually decrease throughout the day, allowing
for temperatures to rebound into the lower 30s to mid 40s by the
afternoon. Surface high pressure briefly builds into the capital
district Monday night with temperatures excepted to dip into the
teens and lower 20s. Winds then shift back to south with warm
air advection ensuing.
A quick moving upper level wave is expected to provide a period
of deeper moisture and upper dynamics late Tuesday afternoon
and Tuesday night. Clouds will increase throughout the day,
along with chances for rain showers. However, it appears as if
the best chance for precipitation will be late Tuesday evening
into the overnight period. Precipitation should start out as
rain or a rain/snow mix in the higher terrain. Afternoon highs
should generally be in the upper 30s to lower 40s area wide.
Long term /Tuesday night through Saturday/...
the long term begin unsettled with a light mix of precipitation
impacting the forecast area. A series of frontal systems will
impact the region into the weekend with overall above normal temps.
Tue night into Wed...an occluded front moves across most of upstate
New York and New England Tue night into early Wed. The triple Point of
the system may pass just south of the capital region. The latest
GFS is about 12 hours faster than the European model (ecmwf)...Canadian ggem and
several gefs members with little or no pcpn at night. The blend of
guidance yields a mixture of light rain/snow with some sleet and
freezing mixing in over the higher elevations and especially outside
the Hudson River valley. We will continue to mention this light mix
in the severe weather potential statement. It should be very brief. Right now, a blend of the
thermal profiles yields some light icing over the Berkshires,
eastern Catskills, and southern Vermont. Lows will be in the upper 20s
to mid 30s. Temps behind this boundary will be mild with increasing
sunshine Wed with weak high pressure building in. Highs will be a
good 10 to 15 degrees above normal with 40s to 50s across the region.
Wed night into Thu...the fast near zonal and split mid level flow
continues. Another short-wave will quickly approach from the Great
Lakes region and southeast Ontario late Wed night into Thu with
mainly isolated to scattered showers. A few snow showers early on
over the southern dacks. This system does not have much moisture
with it, and its warm front will lift north of the region in the
morning. Highs will surge even warmer with the system passing to
the north, as highs will be mid and upper 50s in the valleys, and
mid 40s to lower 50s over the mountains. A few 60f readings may be
possible in the Mid-Hudson valley.
Thu night into Friday...the systems cold front moves south of the
region Thu night with a quick shot of cold advection sending temps
back into the upper 20s and 30s. However, the boundary starts to
lift back as a warm front on Fri, as a stronger system will be
ejecting out of the Central Plains. A chance of showers increases
Friday night into Saturday...low pressure moves into the western
Great Lakes region. Good isentropic lift ahead of the warm front
should provide a widespread rainfall with some Gulf moisture tapped.
The cold front to the system will move quickly across the region to
open the weekend. Temps look to be milder once again for late Feb,
as the storm track has shifted back well north and west of New York and
Aviation /15z Sunday through Thursday/...
a cold front continues to move across southern New York and eastern New
England this morning. An upper level disturbance and secondary cold
front will swing across the region late this afternoon into tonight.
VFR conditions prevail early this morning with just some sct-bkn
cirrus around. The winds are light to calm at kgfl/kpou/kalb.
However, west winds of 10-15 kts with gusts to 20 kts are continuing
at kpsf. Still the 2 kft above ground level winds are mainly west to northwest at
35-40 kts, and wind shear groups were kept in the tafs until 14z-15z
at all sites except kpsf until the low-level jet passes and better
mixing occurs. A tempo for some MVFR mist was kept in until 13z at
VFR conditions continue into the afternoon with stratocumulus
forming in the 3.5-4 kft above ground level at all the sties. We did place some
MVFR stratocumulus in at kpsf towards 20z at 3 kft agl, and this may
lower 1.5 kft above ground level around 00z/Mon. Otherwise we continue to VFR
cigs/vsbys at kgfl/kalb/kpou into 00z/Monday with maybe some snow
showers near kgfl/kpsf. VFR conditions should return to all the
sites after 06z with decreasing clouds.
The winds increase from the southwest/west at 5-10 kts initially,
then will veer to the west to northwest at 8-15 kts in the late
morning into the afternoon with some gusts to 20-25 knots possible at
kalb/kpsf especially in the afternoon. The winds will lighten to 5-
10 kts from the north to northwest between 00z-06z/Mon.
Monday-Monday night: no operational impact. No sig weather.
Tuesday: low operational impact. Slight chance of rain.
Tuesday night: moderate operational impact. Chance of rain...sn.
Wednesday: no operational impact. No sig weather.
Wednesday night: no operational impact. No sig weather.
Thursday: low operational impact. Slight chance of rain showers
no widespread Hydro problems are expected into the middle of
next week with limited chances of widespread precipitation.
A cold front moves across the area later today with some very
light precipitation that will be possible across northern areas,
but total amounts will only be a few hundredths of an inch at
most and will have no impact on rivers and streams.
Milder temperatures are expected into early next week. Although
these warmer temperatures will promote some snow melt during
the day, it won't be accompanied by any significant rainfall and
strong southerly winds, and overnight temperatures will fall
below freezing. This will allow for a controlled and gradual
diurnal melt of the snowpack in place. Only small and minor
rises can be expected on rivers and streams through the early to
middle portion of next week.
With another approaching storm system, a light mix of
precipitation to rain showers is expected Tuesday night into
Wednesday. This looks fairly light and is not expected to have
a major impact on the Hydro service area at this time.
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.