FXUS61 KBGM 250153

Area Forecast Discussion
National Weather Service Binghamton NY
953 PM EDT Thu Sep 24 2020

Northeast PA and central NY should stay dry into the weekend
with summer like temperatures. Unsettled weather with showers
and possible thunderstorms starts Monday.



Any showers will continue to decrease across the Finger Lakes
and Syracuse areas with the loss of instability early this
evening. Some river valley fog develops as well with clearing
skies and good radiational cooling. Updated the overall coverage
of the fog with the late evening update based on trends so far
through the early evening with more locations looking favorable
to see some fog. Otherwise, expect temperatures to stay warmer
than the previous night with lows in the 50s. The warming trend
continues Friday as temperatures peak in the 70s to near 80F in
the warmer spots. Winds shifting to the south/southwest stay
fairly light, peaking only at around 5 mph while skies stay
partly cloudy.


230 PM Update...

The weekend will continue to be rather mild as broad WSW flow
becomes established between high pressure over the western Atlantic
and gathering low pressure over the north central part of the
Nation. Saturday looks to continue the precipitation free conditions
under weak high pressure. Some models suggest light QPF across NEPA
on the northern fringes of a weak wave well to the south of our area
on Saturday afternoon, but not quite ready to latch onto that idea
this early. NAM seemed to be most aggressive with the feature, but I
have little confidence in Saturday afternoon showers right now.

However, moisture does increase Saturday night and Sunday, but there
remains no significant trigger to generate showers. What is being
noted more in this model cycle is a low level response to the
departing surface high offshore and a return of shallow marine layer
moisture into NEPA and possibly the western Catskills late Saturday
night and Sunday morning. Several models were squeezing out very
light QPF and forecast soundings definitely suggest an orographic
drizzle pattern setting up. Forecasters along my southern border
counties are in agreement, thus will increase PoPs overnight
Saturday night with a mention of patchy drizzle in these areas.

For the rest of Sunday, the area looks to break into a warm sector
again with expected temperatures reaching the upper 70s to low 80s.


230 PM Update...

No major changes to this part of the forecast. Looks like the ECMWF
has come around with less phasing of the major polar cyclone with
the southern branch...thus allowing frontal and precipitation timing
to come back in line with the somewhat faster GFS/GGEM solutions.
Still plenty of uncertainty to not make significant PoP
adjustments, though. Prevailing thought toward the better window
of time to get some appreciable rainfall in the area will be
Tuesday into Wednesday...although timing details and a dry slot
remain up in the air. Then...prepare for the early October cool

Previous discussion...

The threat for scattered rain showers will continue to increase
Sunday night into Monday as the upper trough over the central US
deepens dramatically into the srn MS Valley. A series of embedded
short waves will rotate north along the eastern side of the system
and combine with weak instability to produce persistent/scattered
showers and a few thunderstorms Monday afternoon/evening. There may
be a brief break late Monday night/Tuesday morning before
another...potentially more dynamic short wave tracks ne through the
region later Tuesday into Wed morning. There are still a number of
differences with respect to timing, location and intensity among the
suite of model guidance, but this trailing wave looks to be
potentially strong and interesting enough to keep an eye on through
the weekend. The entire upper low over the Great Lakes continues to
wrap up and intensify going into Wednesday, but with some drying and
ridging over the Northeast US...enough to allow the showers to come
to an end.

A noticeable cooling trend will develop early next week with highs
initially in the lower to mid 70s on Monday...but dropping into the
lower to mid 60s by Wednesday. Overnight lows will drop from the 50s
Monday into the 40s by Wed.


730 pm update...

VFR conditions for most sites into Friday evening.

Exceptions could be some valley fog at ELM and RME. RME could
have MVFR vsby fog 9 to 13z due to the increased low level
moisture. ELM should fall to IFR by 08z then rise by 14z. Low to
medium confidence on ELM again. Last few nights ELM had very
little fog. Guidance again has them going down hard. Low level
winds are light. Surface winds are calm already with clearing
skies. The river is still in the 60s but there hasn`t been rain
in about a week. ELM fog checklist did have all 5 cases dropping
below 1 mile.

Winds light and variable tonight becoming southwest at 5 kts

Friday night...Mainly VFR. Possible valley fog at KELM during
the early morning hours.

Saturday into Sunday...Atlantic moisture moves in from the
southwest with maybe some sprinkles for AVP. MVFR likely AVP and
south central NY. VFR at SYR/RME.

Sunday night into Tuesday...Scattered showers and thunderstorms
may lead to occasional restrictions.





NWS BGM Office Area Forecast Discussion

Random Fact

Weather Terms

Flood Warning - General or areal flooding of streets, low-lying areas, urban storm drains, creeks and small streams is occurring, imminent, or highly likely. Flood warnings are issued for flooding that occurs more than 6 hours after the excessive rainfall. These warnings are issued on a county by county basis by the local Weather Forecast Office and are generally in effect for 6 to 12 hours.