Scientific Forecaster Discussion
fxus61 kbgm 221330
Area forecast discussion
National Weather Service Binghamton New York
930 am EDT Tue Oct 22 2019
a strong cold front will bring breezy winds and periods of rain
areawide later today into tonight. High pressure builds back in
Wednesday through Thursday, bringing mainly dry and seasonable
weather. Another cold front approaches the region Friday brining
chances for more showers to end the week.
Near term /through Wednesday/...
Strong warm air advection is developing out ahead of the
frontal boundary, and temperatures will hold steady or slowly
rise through the 50s this morning. Some patchy drizzle develop
across the higher terrain of the Poconos this morning and will
likely continue for the rest of the morning. Only minor
adjustments to the forecast below with the mid-morning update.
Ahead of the front, enough lift and moisture will present for a
widespread band of rain to move through the region ahead of the
front. Rain overspreads the area arriving in the far west
between 11am to 2pm. The rain will move somewhat slowly off to
the east, reaching the I-81 corridor by 2-5pm, then finally our
eastern zones by 4-7 PM. This is expected to be a period of
steady, moderate rain...cannot rule out a rumble of thunder
along the front itself, but not enough confidence to include in
the forecast grids at this time. Used a blend of the latest
hrrr, rap, 3km NAM for timing of rainfall today. Used a similar
blend of models, along with nbm and wpc for quantitative precipitation forecast forecasts for
this event. A surge of deep moisture is still expected to arrive
along and just ahead of the front, with pwats reaching around
1.3 inches for a few hours. Overall, rainfall amounts are
trending down from this system, as it will be quite progressive.
Latest forecasts now only have the steady rain lasting for
about 6-9 hours at any one location. Am now expecting between
0.40 to 0.80 inches of rain for much of the area, with locally
up to 1.25 inches by the time the rain ends tonight. With these
amounts do not expect any significant Hydro issues. Perhaps some
ponding of water on roadways where drains may be clogged due to
leaves etc. Looking for only minor rises of a few feet on area
rivers and creeks by tonight.
Tonight: rain exits from west to east during the evening hours
west of I-81, and after midnight east. Modest cold air advection
takes hold in a west-southwest flow after the frontal passage.
850mb temperatures fall to around +1c by daybreak. This should
elicit a lake response, with a few rain showers skirting our
northern zones off of Lake Erie/Ontario. Lake effect cloud cover
lingers north, but turning partly cloudy from the twin tiers
south into NE PA. May see some patchy fog develop late in the
deeper valleys of the southern tier and NE PA, as surface
ridging nudges in from the South. West-southwest winds 5 to 10
mph (except light/variable in the valleys). Cool with lows
Wednesday: zonal west-west southwest flow of cool air aloft
continues; 850mb temperatures hover around 0c all day.
Therefore, do think there will be lake effect clouds and
showers, but the flow will be around 210-230 degrees, so this
activity will only scrape our far northwest zones. Further south
,across the majority of the area a surface ridge continues to
slowly build in from the south. This will keep the sensible
weather dry and partly sunny. It will be breezy, with west-
southwest winds 10-20 mph and gusty at times. Seasonable
temperatures with highs in the mid to upper 50s.
Short term /Wednesday night through Thursday night/...
high pressure over the region will bring quiet weather and
mild temperatures to New York and PA through the short term period.
After a cool overnight Wednesday night, a southerly flow will
push temperatures to around 60 degrees on Thursday.
Clouds will increase ahead of an approaching storm Thursday
night as temperatures fall to around 40.
Long term /Friday through Monday/...
the long term will begin with an active weather pattern as an
upper level wave spreads showers into the northwestern third of
our forecast area.
Northwesterly flow behind the wave will cause lake enhanced rain
showers Friday night into early Saturday before a dome of high
pressure slides across New York and PA and cuts off the rain showers
A cyclone rotating into Michigan will cause isolated shower activity
over our forecast area for Sunday and Monday.
Aviation /14z Tuesday through Saturday/...
generally MVFR ceilings across the area early this morning, except
still VFR at ksyr and krme.
Low level wind shear is occurring at krme, ksyr, kith and kelm
and is forecast to continue through 14-15z before gradually
decreasing. Marginal at kavp and kbgm.
Ceilings continue to lower through the morning hours, reaching MVFR
or fuel alternate by late morning from the New York southern tier down
across NE PA. Kith, ksyr and krme likely remain VFR, with cloud
decks 4-8k ft agl through 15z this morning.
Expecting widespread fuel alternate, and occasional IFR
restrictions (cigs and vis) in moderate rain late this afternoon
into this evening. Best window for these restrictions seems to
be from about 18z to 23/03z. Highest probability for IFR will
be at kbgm, kavp and krme. Then, some gradual improvement from
west to east toward the end of the taf period, after 23/04-07z.
South-southeast winds 8-15 kts, and gusty today. Winds turn
southwest and decrease under 10 kts after 23/00z.
Wednesday morning...becoming VFR. Patchy fog possible in the
early morning, mainly at kelm.
Wednesday afternoon through Friday morning...mainly VFR with
IFR valley fog possible in the early mornings.
Friday through Saturday...possible restrictions in showers.