Scientific Forecaster Discussion
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Area forecast discussion
National Weather Service Binghamton New York
659 PM EST Fri Dec 13 2019
a major storm system which will track right over New York and PA
tonight through Saturday night. This storm will bring rain
beginning later today and continuing through Saturday. As the
storm passes northeast of our area Saturday night, colder
northwest winds will change the rain to snow before ending as
snow showers and flurries on Sunday.
Near term /through Saturday/...
7 PM update...
increased the coverage of fog tonight and tomorrow, and also
added mention of drizzle to the forecast in replace of light
rain this evening and again in the dry slot that develop Sat
afternoon. Otherwise, the forecast remains on track and mostly
2 PM update...
Widespread rain is moving through the cwa now. A few locations
such as our eastern counties have temperatures around freezing.
The majority are in Pike County PA. Temperatures fall a degree
or two with the rain then should rise the rest of today into
tonight. The threat of freezing rain should end by 5 PM. The
rain this afternoon into evening will last the longest in our
northern Poconos and western Catskills. For the overnight the
main batch of rain moves in ahead of the surface low. The track
is to the northeast just east of our area. This will keep the
heavier rain mostly east. The highest amounts of rain for
tonight and Saturday are nearly an inch for Pike and Sullivan
counties. This is good news with rivers still high from the last
rain event. Some snow will melt too but despite the warm
temperatures winds will be light. A point or two in the
headwaters of the Delaware River could get above caution stage
again this amount of rain. If the track ends up further west
like previous model runs, rain amounts will be higher and minor
flooding could occur Saturday night and Sunday. Not confident
enough for a Flood Watch.
This afternoon Max temperatures will be close to the min temps
tonight. Temperatures at sunrise around 40.
As the surface low moves into New England, a short wave rounds
the base of the digging upper level trough. This will pull deep
moisture and colder air southeast into the area. After a lull
Saturday morning the afternoon into the night will be wet. Storm
total liquid equivalent amounts west of an Elmira to Utica line
will be 1 to 1.5 inches. The tricky part is that the rain during
the rain will change to snow from northwest to southeast
Saturday night. Some higher elevations locations could get a
inch or two in central New York. The highest terrain in Steuben and
Oneida counties could get 4 inches. Snow amounts in nepa the
valleys will be mostly under an inch. Temperatures fall to
Short term /Saturday night through Monday night/...
with the west-northwest flow, moisture will continue to move
southeast into our area keeping the clouds around and be enough
for in the way of lake effect snow showers near the New York thruway
corridor. Momentum Transfer off of BUFKIT soundings show the
potential for 25-35 mph wind gusts at times as well.
Temperatures should stay rather steady or only slowly rise in
the 30's throughout the day.
Winds will decrease Sunday night as high pressure builds in,
shutting off the lake effect. Low temperatures should fall to
around 20 but the winds look high enough still to prevent
tanking temperatures as a result of snow cover.
Our next low pressure system moves into the Ohio Valley Monday
before tracking over the region on Tuesday. Modeling has
continued to trend further and west with the track of this
system. As a result, more warm air both and surface and in the
mid-levels should work into most of the region at some point
during the event. This would cut down on potential snowfall while
increasing the chances for a period of freezing rain across
most of the region.
A warm front ahead of the low will move into the area Monday
night. Moisture will overrun the front producing a period of
snow which moves in from south to north Monday night. The best
forcing and lift looks confined to locations further south of
the region through Monday night. If this forcing was to
translate further north than currently anticipated, snowfall
intensity may also increase from our forecast. Light
precipitation is currently anticipated to overspread the region
Monday night. Warmer air aloft typically GOES further north than
modeled which is accounted for in this forecast. The warmer air
aloft should allow most locations to transition to freezing rain
and even rain as the surface warms. What precipitation types
that will be seen are still highly dependent on the expected track
of the storm which will be fine tuned in the next few days.
Temperatures rise into the 30's and 40's Tuesday before falling
again Tuesday afternoon. A non-diurnal temperature spread is an
increasing possibility as well.
Long term /Tuesday through Friday/...
the low pressure system which passes over our region Tuesday
will most likely be pulling northeast of cny/nepa by Tuesday
night with the focus returning to lake effect potential through
the end of the week.
Cold and unsettled conditions are expected with scattered to
numerous snow showers for Our Lake snow belt areas and flurries
further south. Highs will struggle to get into the 20's
Wednesday through Friday with overnight lows at least in the
teens. If the operational GFS and European model (ecmwf) are to be believed
temperatures will have to be adjusted even further downward
given the modeled boundary layer temperatures.
Aviation /00z Saturday through Wednesday/...
low pressure developing over the Carolinas this evening will
lift to the N/NE tomorrow with a broad area of light rain
through most of the day. A relative lull in the rain is evident
across much of the region this evening with many areas seeing
patchy fog and drizzle. A push of more widespread rain will be
seen after 04-05z this evening before a pocket of drying occurs
along and east of I-81 roughly 12z-19z Sat. IFR cigs will
likely dominate through the next 24 hours with periods of LIFR
or below alt minimum cigs and vsbys. There may be some
improvement late morning and early afternoon Saturday, but a
likely return to IFR or worse conditions after 19z as the next
slug of moisture pushes in from the SW.
Southeast winds 5 to 10 kts become east and light tonight and
Sat morning before shifting to the W/NW 5 to 15 kt late Sat
Saturday evening through Sunday... rain changing to light snow
with MVFR/IFR restrictions. Northwest wind at 10 to 20 kts with gusts
20 to 30.
Sunday night and Monday...VFR with winds decreasing.
Monday night and Tuesday...MVFR/IFR restrictions with a wintry
Wednesday...MVFR/IFR restrictions in cny maybe reaching avp.