Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Binghamton New York
423 am EDT Monday Apr 27 2015
hit and miss showers will dot central New York and northeast
Pennsylvania into this evening...as upper level disturbances
impact the area. High pressure will build into the region Tuesday
through Wednesday...to bring dry weather...and milder
Near term /until 6 PM this evening/...
415 am update... satellite/radar imagery continue to show moisture
rotating into the region from the north...as an upper level low
retrogrades slowly westward over the Canadian Maritimes. Despite the
increasingly moist environment...overall forced lift will be
fairly weak today...owing mainly to poor jet dynamics. Thus...probability of precipitation
will be kept on the low side...with only isolated-scattered shower coverage
Lack of insolation will keep temperatures below average for late April...with
highs mainly in the 50s this afternoon.
Short term /6 PM this evening through Wednesday/...
430 am update... isolated-scattered showers should linger this evening...before
diminishing late tonight...as the above mentioned upper low begins to
kick eastward again away from the region...over the western Atlantic.
Tue-Wed...dry weather is expected...as surface ridging builds southeastward from
ont...and shortwave ridging develops in the mid-lvls. Although clouds could
linger early in the day Tuesday...with moisture perhaps trapped
underneath building heights aloft...we should see some clearing by/during
Tuesday afternoon...with partly-mostly sunny skies then anticipated Wednesday.
Better insolation and air mass modification should push high temperatures into
the upper 50s-middle 60s range.
Long term /Wednesday night through Sunday/...
GFS and Euro are slowly coming into agreement on the closed low and
developing coastal system in the long term...with the GFS trending toward
the Euro. Long WV pattern is similar with flat ridging into the Upper Middle
west. Dfrncs continue to Stem from the handling of a northern stream WV
dropping into the east CST trough...and it/S interactions with a
strong southern stream system. Euro continues to keep a separate and
dominant southern stream storm moving off the middle Atlantic CST...keeping
a weak trough to the north...while the GFS wants to rapidly deepen
the northern WV and capture the southern WV resulting in a deep system off
the CST and a closed upper low over western New York. GFS solution wld likely
produce a colder and wetter scenario...perhaps some snow...for the
forecast area. Euro wld continue to keep the area below normal...but much lighter
and all liquid on the precipitation.
With the GFS/S tendency to create bogus deep storms in the long
term...will continue to follow the Euro solution and keep low chance probability of precipitation
with below normal temperatures for much of the extended period. This also allows for
a continued gradual imprvmt in the weather into the first part of the
weekend...although some light precipitation cannot be ruled out.
Aviation /08z Monday through Friday/...
a few upper level disturbances will drop south through the taf
period as we will remain in northerly flow aloft. These
disturbances will create an environment conducive for showers.
Showers will be temperature dependent... thus areas where temperatures
are near or below freezing will see snow... and with temperatures above
freezing... precipitation will be rain. The chance for rain will prevail
over much of the region starting around sunrise and last through the
afternoon and evening. At this time... VFR conditions prevail across the
region. Northerly flow generally creates downsloping... thus
believe we will just see a brief period of MVFR ceilings early this
morning and sites will see mostly VFR for much of the forecast.
After 00z tonight... the flow will transition to a more
northwesterly flow... and the chance for low end MVFR and IFR ceilings
increase. At this time... put low end MVFR at kbgm and ith as confidence
is the high.
Winds will become westerly and gusty this afternoon with an
occasional gust around 20-25 knots.
Monday night...possible MVFR/IFR ceilings at times due to the cool northerly flow.
Tuesday - Thursday...mainly VFR.
Friday...possibly MVFR-IFR restrictions with rain and br.