189
FXUS61 KBUF 130547
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
147 AM EDT Mon May 13 2024

.SYNOPSIS...
High pressure will move from the Ohio Valley to the Mid Atlantic
overnight, bringing mainly dry weather to our region. A warm front
will move across the area Monday with a few periods of showers and
possibly a thunderstorm or two. This front will usher in a period
warm and unsettled weather which will last through the middle of the
week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Surface high pressure will drift from the Ohio Valley to the
Mid Atlantic tonight, with a mid level ridge briefly moving
across the eastern Great Lakes. This will provide mostly dry
weather for most of the night, with varying amounts of cloud
cover. Radar is picking up on some weak echos which may result
in a brief period of sprinkles. For those attempting to see the
Aurora Borealis again tonight, expect a few intervals of clouds
that last for a few hours at any given location, with periods
of partial clearing. Not ideal, but less cloud cover than last
night.

Late tonight through Monday, a warm frontal segment and 40 knot LLJ
will move across the area as the ridge departs to the east.
Increasing isentropic upglide and moisture transport associated with
these features will bring showers into Western NY around daybreak,
with the rain chances spreading quickly east from there Monday
morning, arriving in the eastern Lake Ontario region during the
afternoon. Modest diurnal instability may support a few spotty
thunderstorms in the afternoon and evening. A gusty southwest wind
in the warm sector behind the cold front will support an expanding
stable lake shadow ENE of Lake Erie Monday afternoon, with mainly
dry weather within this stable lake shadow following the morning
showers.

The southwest winds may gust in the 20-30 mph range areawide, and up
to 35 mph northeast of Lake Erie as the stronger winds aloft
effectively downslope off the dome of stable air over Lake Erie.
Temperatures tomorrow afternoon will be about 10 degrees warmer with
highs in the upper 60s to mid 70s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
Unsettled weather will be the predominate theme during this period
with chances for showers and thunderstorms.

Monday night...there appears to be a brief lull in most of the
shower activity but still can`t say it will be completely dry
overnight. Have low end PoPs (less than 30%) for much of the region.
Closer to the frontal boundary to our north-northwest for locations
along the south shore of Lake Ontario and North Country will see the
greatest potential for showers. Overall a mild night with lows found
in the 50s for most locales.

The nearly stationary frontal boundary to our north and northwest
Tuesday will draw closer or even sag into the region. Guidance
continues to advertise several waves traversing this front which
will `potentially` bring numerous showers and thunderstorms through
Tuesday. Given that PW values will be hovering in the 1.15"-1.35"
range, and overall light flow (small MBE vectors) any convection may
produce periods of heavy rain at times. We will need to keep an eye
on this potential. As was mentioned...severe weather still looks
very limited with unfavorable shear profiles and the lack
instability. Now for temperatures...the challenge here will be the
position of the front and overall precipitation coverage. Still
thinking we will see highs in the upper 60s for most locales but
some spots could even climb into the low 70s.

Tuesday night through Wednesday...the speed and track of the
eastward advancing low will determine weather we continue to see wet
weather or a slow but gradual drying trend.

Wednesday night...still looks like there will be some lingering
showers but an overall drying trend does take place.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
A progressive flow aloft will maintain chances for showers and
thunderstorms this period. Thursday may end up dry, with low PWATS
and a narrow ridge of high pressure nearby...this between an east
coast low, and trough across the Plains. However there is a
possibility that a few showers from the east coast low sneak far
enough westward into our eastern CWA.

This western trough will push eastward, likely in the Friday to
Saturday timeframe...with still a good deal of model spread to
narrow down it`s passage. Behind the trough lowering chances for
precipitation, through a secondary trough dropping out of Canada may
bring chances for showers to the North Country. Temperatures will
average above normal, especially Friday ahead of the trough, and
again on Sunday when a milder airmass begins to push northward.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
VFR conditions are across the eastern Great Lakes region late
tonight. An area of mid-level clouds extends north-south across
western NY and will move east through the overnight hours. Regional
radar shows weak echoes which may result in a brief period of
scattered sprinkles at KROC and KART through daybreak. The
backedge of the cloud deck will move into KIAG, KBUF, and KJHW
late tonight. Valley fog may form across the western Southern
Tier which could produce MVFR/IFR at KJHW for a brief period. A
westerly low-level jet will strengthen across the region through
Monday morning. There will be a brief period of low-level wind
shear prior to surface winds increasing Monday morning.

A warm front will move across the region Monday afternoon. Showers
and a chance of thunderstorms will track across western NY through
Monday morning and east of Lake Ontario Monday afternoon. VFR
conditions will continue, however low-end VFR will move into KART
Monday afternoon. Any heavier showers or thunderstorms could produce
a brief period of IFR but confidence is low of reaching a TAF site.

Outlook...

Tuesday...MVFR/IFR with the likelihood for showers and thunderstorms.
Wednesday...MVFR/IFR with showers, especially for southern and eastern
portions of the area. Improving later Wednesday.
Thursday...VFR.
Friday...VFR. A chance of showers late.

&&

.MARINE...
Southwesterly winds will increase following the passage of a warm
front late tonight and into Monday. Winds and waves will likely stay
below Small Craft Advisory criteria, although it will become choppy
at times. Otherwise, winds and waves are expected to remain well
below Small Craft conditions with just some light chop at times
through at least Tuesday.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...None.

&&

$$

SYNOPSIS...Apffel/Hitchcock
NEAR TERM...Apffel/Hitchcock/HSK
SHORT TERM...AR
LONG TERM...Thomas
AVIATION...HSK
MARINE...Apffel/Hitchcock