-- Discussion containing changed information from previous version are highlighted. --
560
FXUS61 KBGM 100810
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
410 AM EDT Fri May 10 2024

.SYNOPSIS...
Widespread rain showers will impact the area today, before
decreasing in coverage tonight. Additional on-and-off showers are
anticipated for this weekend, along with below normal
temperatures. A gradual warm-up is expected next week, but
showers will remain in the forecast.

&&

.NEAR TERM /THROUGH SATURDAY/...
345 AM Update:

As a surface low passes to the south, a shortwave trough will be
pushing through the area today. This will set the stage for
widespread light to occasionally moderate rain showers. Despite
a prolonged period of rain, rates will be rather light. Flooding
is not a concern with this system due to the rather light
rainfall rates, combined with green-up underway or complete
across the area. With a cool airmass in place and the trough
moving through, temperatures will be cool for this time of the
year; mainly in the upper 40s to mid 50s. This will make it feel
more like late March or early April, rather than early-mid May.

There will be some lingering showers tonight, with perhaps some
dry time heading into early Saturday as the first shortwave
trough departs to the east. Lingering low-level moisture should
keep skies mostly cloudy, but some patches of partial clearing
will be possible. With this lingering moisture, patchy fog will
also be possible. Lows are expected to be in the upper 30s to
upper 40s. There is a low potential for some patchy frost in any
areas of partial clearing, but with marginal temperatures and
still mainly cloudy skies, the chances are that this will not
occur.

The mainly dry period will be short-lived as yet another wave
approaches the area by Saturday afternoon. This will bring a
renewed chance for some showers, with perhaps a rumble of
thunder across the Finger Lakes Region. The best chance of rain
showers will be for areas west of I-81 (especially the Finger
Lakes Region). Farther south and east (towards the Poconos-
Catskills), conditions may remain mainly dry until Saturday
evening with perhaps some partial sunshine during the day.
Temperatures will again be cooler than normal, with highs
expected to be in the mid 50s to near 60 degrees.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
-- Changed Discussion --
400 AM Update

Cool, showery weather continues over the region Saturday night and
Sunday as a closed off 700/500mb low slides east over the region.
Despite the cool air aloft (+1C at 850mb and -23C at 500mb)
there looks to be very limited, if any instability due to the
cool surface temperatures in the 40s overnight and 50s to
perhaps low 60s during the day. Can`t rule out an isolated
rumble of thunder, but overall very low probabilities.

The low exits fairly quickly Sunday night, replaced by a transient
shortwave ridge. This will bring dry weather, with partial clearing.
There is no strong surface high, so some clouds may linger and light
southwest winds will be present. Overnight lows will be rather cool,
dipping into the 40s areawide. Model guidance continues to be in
fairly good agreement that a front will quickly drop into the area
from the north-northwest on Monday. Out ahead of this boundary,
there could be enough daytime heating for modest instability to
build, as highs reach the mid-60s to lower 70s. The front will
initiate another round of showers, and perhaps some thunderstorms
through the day, especially in the afternoon over Central NY.

The surface boundary looks to stall over our region Monday night, as
the main upper level trough, and support remains north, with a zonal
500mb flow over our region. This will keep the potential for rounds
of showers to move over the area overnight. For now, kept chance
PoPs in the forecast. Not as cool, with lows in the 50s.
-- End Changed Discussion --

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...

-- Changed Discussion --
400 AM Update

Trends in the latest 00z model guidance are for increasing PoPs,
rainfall amounts and thunder chances on Tuesday. However, on the
other hand, the latest guidance is now trending drier later
Wednesday and especially Thursday with an upper level ridge.

A low pressure system approaches from the Tennessee Valley Monday
night into Tuesday. Moisture spreads northeast along the above
mentioned stalled frontal boundary. Stuck close to the latest NBM
ensemble guidance which gave solid likely to even borderline
categorical PoPs on Tuesday, with a slight chance to chance for
thunderstorms as well...depending on how much CAPE/instability
can develop in the unsettled pattern. Overall, it is still not
looking very unstable and with dew points in the 50s, the
rainfall should not be overly heavy. This system will be
something to monitor moving forward, in case rainfall amounts
trend higher. Highs are near average in the mid-60s to lower
70s once again.

Behind this system drier air begins to move in from NW to SE
Tuesday night into Wednesday. There are timing differences in
the 00z deterministic guidance, with the GFS lingering more
showers into Wednesday, while the ECMWF dries our weather out
faster. For now, stayed close to the NBM ensemble guidance...but
did lower PoPs some to account for the latest trends. Temperatures
do not change much compared to Tuesday.

Model guidance seems to be coming into much better agreement on
a period of dry and warm weather Thursday, under an upper level
ridge. Lowered PoPs below what NBM was suggesting to account
for this trend. Bumped high temperatures up well into the 70s,
as skies are forecast to be mostly sunny. Rounding out the long
term period, there is uncertainty on the timing of the next low
pressure system. Some of the guidance brings it into the area on
Friday, while other guidance keeps it dry next Friday. With the
uncertainty this far out in time, decided to remain very close
to the NBM/ensemble guidance. This gave 30-40% chance for
showers. Temperature remain nearly unchanged, back in the 70s.
-- End Changed Discussion --

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
Despite rain showers around, ceilings and visbys remain at VFR
as of 06Z. Still expecting this to become mainly MVFR to Fuel
Alternate over the next several hours. Despite guidance hinting
at IFR conditions this morning, this is looking less likely and
therefore kept restrictions no worse than Fuel Alternate for
now. Best chance for some IFR restrictions will actually be
tonight after the bulk of the rain moves out, as it is possible
that lingering low ceilings and/or fog/mist may be present.

Outlook...

Saturday through Tuesday...Occasional rain showers may
bring intermittent restrictions as multiple disturbances pass
through the region. Some periods of mainly VFR conditions
possible in between disturbances, but timing of this is
uncertain.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.

&&

$$

SYNOPSIS...BJG
NEAR TERM...BJG
SHORT TERM...MJM
LONG TERM...MJM
AVIATION...BJG