Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Binghamton New York
1008 am EDT Friday Oct 31 2014
clouds will increase today...but it will be mainly dry. A chilly upper
level disturbance will slowly approach the region tonight through
Saturday...bringing some rain showers...eventually mixing with
snow showers as cooler air works into the region. Once this system
moves away by later Sunday...drier weather...with moderating
temperatures...should then be the rule into early next week.
Near term /through tonight/...
10 am update...
have continued trend of further delaying mentionable rain chances.
Clouds will increase but basically a dry day for most...with
developing showers mainly west of Penn Yan-Corning. Then for
tonight...Allegheny Highlands will have a good chance of showers
but elsewhere the chances will only slowly increase and be focused
to mainly after midnight.
Previous forecast discussion...
300 am EDT update...
weak high pressure is over the region this morning and quiet and
dry weather is present. The upper level trough that will bring
showers over the region today is located over central WI. This
trough will continue to dig south and amplify over the Midwest
this afternoon. The strongest forcing with this system will stay
well to the south of New York and PA. However the middle level trough will
remain close enough that this will provide enough support for
showers and mostly cloudy skies this afternoon and evening over
the County Warning Area. There are some breaks in the clouds this morning over the
far southeast portion of the County Warning Area... but do not expect this to last long.
Expect mostly cloudy skies to return over the southeast shortly after 18z
Expect the onset of showers to be later than previously thought.
With showers pushing into the far western County Warning Area around 18z. Showers
will be scattered like in nature and will spread eastward through
the afternoon/evening. Temperatures this afternoon will reach the upper
40s to low 50s... thus expect all showers this afternoon/early
evening to be rain. When temperatures start to cool off after 00z tonight
there is a slight chance that some of the precipitation will fall as a
mix of rain and snow. The chance for snow will be primarily over
the higher terrain. Temperatures are expected to range tonight in the
lower 30s to lower 40s.
Short term /Saturday through Sunday night/...
440 am EDT update...
by Sat morning the base of the upper level trough will start to move
over SC. Then... by 00z Sat the main axis will be off the eastern
Continental U.S.. the main forcing with the upper low will not impact our
region... and the path of the upper low will keep the coastal
system well out of our area. However... the upper branch of the
potent upper low will provide enough support for the showers to
develop across the County Warning Area through Sat night. The system will continue
to move east through the forecast period.
As the main axis moves east cooler air will start to drain into
portions of central New York and northeast PA. 850mb temperatures will start as
negative one 12z Saturday... fall to negative three 00z Sunday...
then fall to negative eight by Sunday afternoon. Due to strong
cold air advection... all rain showers will transition over to snow by Sunday
morning as the atmospheric profile will then support snow growth.
Saturday evening environmental conditions look plausible for the
development of lake effect snow showers off The Finger lakes. The
longevity of The Finger lake bands will be determined by the mean
boundary layer wind and the moisture profile right above the surface.
Sunday morning the chance for precipitation starts to drop off. Upslope
induced snow showers are possible during the day. But due very dry
air moving into the region and strong subsidence aloft... the
chance for accumulating snow showers are slim. Expect flurries at
best. Winds during the afternoon on Sunday will be breezy with
winds sustained around 10-20 miles per hour with gusty near 30 miles per hour. Thus
with temperatures only increasing into the upper 30s to low 40s... Sun
afternoon will be rather chilly. Sunday evening will br dry with
partly cloudy skies as high pressure starts to build into the region,
Long term /Monday through Thursday/...
315 am update...no significant changes made to the extended
forecast as 00z model runs are consistent with previous.
1 PM Thursday update... deep upper-level trough along the East Coast at the
start of the period...will be in the process of lifting away to the NE
early next week. In its wake...surface ridging...and also shortwave ridging
aloft...will lead to mainly dry weather and moderating temperatures Mon-Tue.
Our next shot at precipitation will likely come towards the middle of next
week...when an upper-level trough within an increasingly zonal flow
aloft is prognosticated to approach from the west...along with a surface frontal
complex. As a result...we've inserted scattered showers starting later
Tuesday night...then persisting through at least Wednesday.
As alluded to above...readings will be on the upswing next week...with
daily high temperatures generally in the 50s-lower 60s.
Aviation /14z Friday through Tuesday/...
VFR conditions are generally expected through this taf period.
Scattered strato cumulus continues to drift across the region this
morning in weak low level flow. Through much of today middle level
clouds will increase over the region as surface low pressure over Lake
Huron drops south into the Ohio Valley. This evening ceilings will
lower to around 4k feet with light rain showers near the ksyr/kelm
East/southeast winds around 5 knots later this morning and continuing
Sat-Sat night...occasional restrictions are possible in rain/snow showers.