Scientific Forecaster Discussion
fxus61 kbgm 221028
Area forecast discussion
National Weather Service Binghamton New York
628 am EDT Thu Mar 22 2018
a northerly flow of cold air will continue across the area into
the weekend. With that cold air will come scattered snow
showers from time to time.
Near term /through tonight/...
surface gradient does not weaken as the storm deepens as it
moves slowly off to the east. This will keep a north flow of
cold air over the area through the day, becoming gusty as mixing
brings some of the stronger winds down near the surface. There
will be a a decent amount of clouds around in the cold
advection, but flurries are not expected with limited moisture
and the very Cold Lake. Temperatures will be cold enough for all
snow, even in the afternoon and despite the Spring sun. Max
temps Friday will be a good 10 degrees below normal, along with
a damp and gusty north wind. Little change expected Friday night
as the upper low meanders off to the east.
Short term /Friday through Saturday night/...
500 mb closed low passes across the area late tonight and on
Friday bringing deeper moisture, increased instability, and
eventually scattered snow showers, especially over the New York zones.
Even with the continued presence of an upper-level trough over the
northeast, a transient surface high passing east of Hudson Bay
should allow Saturday to be mainly dry for most of the forecast
area. As the day progresses, though, synoptic scale forcing will
likely increase over our region as the center of the upper low
pivots southeastward toward the coast. This may aid in the
development of some light snow showers over parts of the forecast
area by Saturday night. Little, if any, accumulation is expected at
Long term /Sunday through Wednesday/...
an upper trough axis remains near the northeast U.S. Coast at the
start of the long term period. A weak surface trough, combined with
additional shortwave energy to bring a little bit of light
precipitation to eastern parts of the region (mainly) during the
morning. Forecast soundings suggest that the dominant precip type
will likely be snow, but given the drying that's expected to occur
in the boundary layer during the morning, coverage/amounts appear to
be limited at this time.
This system should move farther offshore Sunday night into Monday,
as the next upper-level trough digs into the western part of the
country. Downstream amplification of the flow aloft will result in
ridging (generally both at the surface and aloft) across our region
for early next week. Given temperatures at 850mb approaching 5
degrees celsius by Tuesday afternoon, especially over western parts
of the forecast area, I can't rule out a few locations reaching 50
degrees. The most likely result, though, will be near normal
afternoon temperatures for late March, with most places in the
middle and upper 40s.
Ridging will start losing its grip on our weather Tuesday night. The
upper trough over the western U.S. Is expected to head east,
allowing a cold front to reach from the u.P. Of Michigan into the
mid-Mississippi Valley by Wednesday morning. Closer to home,
atmospheric moisture will deepen in a strengthening southwesterly
flow aloft. This should result in greater odds of seeing
precipitation beginning Tuesday night and continuing through
Wednesday as a warm front moves northward over the area and the cold
front inches closer.
It's really too early to pinpoint a precipitation type at this
range given inherent uncertainty present for days 6 and 7 of the
forecast. Medium range models, however, indicate warm advection
developing in the 850-700 mb layer at some point Tuesday night
or Wednesday. Forecast soundings are latching onto this as well,
with a saturated profile and a warm nose indicated within the
layer. Based on available information, I think we might start
out as wintry or mixed precipitation Tuesday night. Everything
should become a cold rain at some point Wednesday.
Aviation /12z Thursday through Monday/...
VFR conditions are expected into tonight. East Coast snow storm
will continue to pull east leaving drier air and a north flow
over the area. Winds will become gustier after sunrise as the
low spins up and mixing brings higher winds to the surface. A
VFR SC deck will likely develop, but no snow showers are
expected. Winds become lighter again tonight as the gradient
weakens. Tonight, and upper low passes across the region
bringing deeper moisture and a continued north flow. This will
likely bring a MVFR deck to may stations, and perhaps a few snow
Thursday night through Monday...mainly VFR. A period of lower
ceilings is possible Thursday night into Friday.