Scientific Forecaster Discussion
fxus61 kbgm 231033
Area forecast discussion
National Weather Service Binghamton New York
633 am EDT Mon Apr 23 2018
high pressure will reside over the region through tonight with
continued mostly sunny conditions today. Clouds will increase
tonight with a low pressure system that will bring rain for the
mid week period.
Near term /through Tuesday/...
High pressure over the region will bring US one more sunny day with
light southerly winds today. The high pressure system will then
start to move out of the area tonight. As this occurs, low
pressure will slowly track up the East Coast bringing an
increase in clouds Tuesday and some rain spreading into the
region by late in the day.
Went on the warmer end of the model guidance with the forecasted
highs in the 60's across the region. This is largely based on the
increase with model temperatures in the boundary layer and
another day of abundant sunshine expected. Temperatures were
updated with the morning update to reflect a few locations
which had a typical sharp temperature drop before sunrise.
Temperatures should rise fairly quickly this morning. This
forecast also trended dewpoints a bit lower than modeled with
the potential for mixing. While relative humidity values may drop to around
30%, winds will be light enough to preclude any fire weather
concern. The lav guidance appears to be picking up on the lower
dewpoints and was incorporated with the morning update.
Light southerly winds and increase in high clouds will keep
temperatures several degrees warmer tonight, with lows in the
mid 30's to low 40's. Temperatures Tuesday will be highly
dependent on the amount of cloud cover. Northern portions of the
region from Syracuse to Rome that see more sunshine look to
have another day well into the 60's. Areas further southeast
that see more clouds will be closer to 60 for actual highs.
The NAM and Canadian are on the faster end moving rain into the
region Tuesday afternoon with the European model (ecmwf) a few hours slower. For
now, leaned slightly toward the faster model guidance with some
potential for light rain by the afternoon hours and more
widespread rain holding off till Tuesday night. Rain chances
will be highest the further southwest you go across the region
Short term /Tuesday night through Thursday/...
355 am update...
rain will continue to overspread the region Tuesday night and
Wednesday as a short wave passing through the Great Lakes phases
with a cut-off upper low moving from the srn appalachian mtns newd
to near New Jersey. A weak surface low associated with this system will
track out ahead of the upper low from the Carolinas to the New
England coast. A push of warm moist air northward ahead of the low
will prime the air mass for widespread rain showers into Wed night.
The most favorable period for moderate to possibly heavy rain will
be during the day Wednesday with the sfc low near the Delmarva
Peninsula resulting in tight thermal packing within a moderate
baroclinic zone lifting north through ern PA and central New York. The
development of a weak-MDT layer of mid lvl f-gen should be enough to
enhance precipitation efficiency during the late morning and
afternoon hours on Wednesday. Rainfall amts from Tue night through
Wed night should range from 0.5 to 1 inch...with locally higher
isolated amts in the elevated regions of the Poconos and Catskills
above 1500 ft.
There are still some timing/placement differences among the
guidance, with the NAM and GFS being the most progressive with the
incoming S/W phasing with low to the south and pushing it much
quicker to the NE than the CMC and especially the ECMWF, which is
the slowest. How long the rain showers linger Wed night and Thursday
will greatly depend on this transition period. Should see available
deep layer moisture slowly decrease late Wednesday night and through
the day Thursday as the low pressure system exits to the NE.
Kept the higher chances of rain confined to the northern
counties with only low chances for rain showers during the day
Temperatures will remain fairly mild Wed and Thursday with highs in
the 50s and lows in the upper 30s and 40s.
Long term /Thursday night through Sunday/...
355 am update...
weak ridging aloft and an associated weak surface high moving
through Thursday night and Friday will likely keep weather
conditions quiet before the next system moves in for the weekend.
There still remains radically differing solutions among the
deterministic guidance with the latest 00z European model (ecmwf) pushing through a
basic looking cold front on Saturday, with a round of cool rain
showers, and high pressure building back in on Sunday. The 00z GFS
brings a low up the coast with high pressure behind it and a
trailing cold front further to the west...which washes out as it
lifts to the north on Saturday with limited precip before high
pressure builds in late in the weekend. The 00z CMC develops a large
cut-off upper low over the Tennessee Valley Friday night and lifts this
system to the NE Sat and Sat night with widespread rain showers
expected and a cool and dry air mass filling in behind the
system on Sunday. Will have to await further model runs as the
week progresses to get a better handle on how the pattern will
Temperatures on Friday may actually be above normal with afternoon
highs in the lower 60s. Overnight lows in the 30s and lower 40s are
likely through the weekend. Highs on Sat and sun may only reach into
the lower to mid 50s. There is a glimmer of Spring on the horizon as
most models have the polar jet shifting well to the north next week
and the strongest push of warm air this season...with temperatures
well above average.
Aviation /12z Monday through Friday/...
VFR through the taf period. Skies will be clear with some south
to southwest winds from 5 to 10 knots in the afternoon today.
Some cirrus will start moving into the region after 00z tonight
then become scattered toward sunrise Tuesday. Some of our more
biased aggressive data hints at low level wind shear for ksyr around 12z
Tuesday. However, a closer look at this gives the general
impression low level wind shear criteria will not be met. High confidence.
Tuesday morning...VFR with ceilings lowering. High confidence.
Tuesday afternoon...rain developing with some restrictions
possible toward sunset. High confidence.
Tuesday night through Thursday... some restrictions likely with
rain showers. Moderate confidence.
Thursday night and Friday...VFR. Moderate confidence.