Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus61 kbuf 170246 
afdbuf

Area forecast discussion
National Weather Service Buffalo New York
1046 PM EDT sun Jun 16 2019

Synopsis...
a frontal boundary will remain stalled just south of the area
through Wednesday with a chance of a few showers at times
across the southern tier. Weak high pressure over southeast
Ontario will keep the rest of the area mainly dry with temperatures
near average.

&&

Near term /through Monday/...
a frontal boundary has sagged south of our region this evening.
Rain showers have tapered off with a shortwave now well to our
east, and the remainder of the night should be dry. Cannot rule
out a stray shower near the state line with the frontal boundary
nearby, but this will be isolated at best.

Fog may develop tonight for two reasons. There may be fog across
higher terrain due to low level moisture and cloud bases lowering
to the surface. Also, any clearing south of Lake Ontario will
likely be followed by some radiation fog. This will be more patchy
in nature, but potentially more dense.

On Monday, Buffalo and Rochester and areas north will remain dry
with periods of sunshine due to high pressure ridging southward into
the region. Temperatures will also be much closer to normal with
highs in the lower to mid 70s. The western southern tier will be
closer to the stalled frontal boundary, and with more moisture
scattered showers and possibly a thunderstorm may develop along or
inland of the lake breeze Monday afternoon.

&&

Short term /Monday night through Wednesday night/...
the period will start out mainly dry with a cold front across
central Pennsylvania. Any showers across the southern tier will move
east into the evening hours. A shortwave trough will track across
the Ohio Valley Monday night while low pressure develops and moves
into Indiana and Ohio. Strong moisture transport and warm air
advection will occur south of cold front into Tuesday. This will
keep most of the rain to our south as high pressure resides across
the eastern Great Lakes. Light flow and daytime heating will allow
lake breeze circulations to take place by afternoon. Dewpoints will
in the low 60's across western New York will allow some showers to develop.
A thunderstorm can't be ruled out across the western southern tier.
Shower activity will diminish into Tuesday evening leading to dry
conditions overnight.

High pressure will persist across the eastern Great Lakes Wednesday
while low pressure remains across the northern mid-Atlantic region.
A light flow will persist across the region and daytime heating will
result in lake breeze circulations again. Dewpoints in the upper
50's and low 60's will result in some instability and scattered
showers and thunderstorms are likely late morning into afternoon.
Any shower activity will subside Wednesday evening. The next system
of note will approach the eastern Great Lakes from the Ohio Valley.
Moisture will increase overnight with rain moving into the western
New York by Thursday morning.

&&

Long term /Thursday through Sunday/...
its been a wet month for the majority of the region so far...and
unfortunately that trend is going to continue. In fact...there is
relatively high confidence that another soaking rain is on the
horizon.

As we open this period on Thursday...a stalled frontal boundary will
extend from about St Louis and the upper Ohio Valley to the Mason-
Dixon line. There is strong consensus between many of the gefs
ensemble members...as well as the operational GFS and European model (ecmwf)...that a
wave will track to the east along this boundary. While the strongest
forcing (40-50kt llj) and deepest moisture will be to our south over
Pennsylvania and parts of the mid Atlantic region...precipitable water values of
1.5" and relatively deep lift will support a fair amount of rain
over our region. This will especially be the case across the
southern tier counties where the rain could be heavy at times with
amounts in excess of an inch be possible. Pops on Thursday will
range from likely across the north country to categorical south of
Lake Ontario.

The well organized but relatively weak sfc low will continue to the
east across New Jersey during the course of Thursday night. While
the bulk of the forcing associated with this system will exit as
well...there will be more than enough moisture remaining in its wake
to support likely pops for showers...especially during the first
half of the night.

General hgt rises will be found over the lower Great Lakes on
Friday...as high pressure centered over Hudson Bay will attempt to
nose south across the lower Great Lakes. While this should encourage
fair dry weather...there is some 'debate' among the various guidance
packages as to the amplitude of the mid level ridge that will be
centered to our west. A higher amplitude ridge may allow for a
subtle shortwave to drop tot he south across our region with a
resulting shower threat. Will thus carry chc pops for Friday...but
am definitely leaning towards a mainly dry day.

There is greater confidence that dry weather will be in place for
Friday night and Saturday...as the mid level ridge will amplify with
its axis pushing east to our region.

As we close out this period though...the ridge axis will exit to our
east and open the door for the next shortwave and influx of moisture
to move into the lower Great Lakes region. This could lead to the
next round of showers to close out the weekend.

&&

Aviation /03z Monday through Friday/...
for the 00z tafs VFR flight conditions are found to the north of the
southern tier, while a deck of low stratus continues to grip the
southern tier. A frontal boundary remains just to the south of our
region, and these low clouds with IFR flight conditions will likely
persist through most if not all of the next 12 hours.

Skies will begin to clear from north to south tonight, and these
clearing skies and light winds may allow for some patches of ground
fog late tonight.

Monday VFR flight conditions will be widespread towards the north,
while morning IFR (kjhw) across the southern tier will
improve...though some scattered showers will become possible through
the afternoon.

Outlook...

Monday night and Tuesday...VFR to MVFR in scattered showers and
thunderstorms, mainly across the southern tier.

Wednesday...VFR.

Thursday...MVFR/IFR. Showers likely.

Friday...MVFR. A chance of showers.

&&

Marine...
a frontal zone will stall from the Ohio Valley to PA through
Wednesday while weak high pressure settles into southeast
Ontario and southern Quebec. This will keep a weak pressure
gradient across the eastern Great Lakes, with light winds and
flat wave action.

Low pressure will track near the eastern Great Lakes on Thursday,
but the track and strength of the low is uncertain. Winds and waves
may approach small craft levels depending on the development of this
system.

&&

Buf watches/warnings/advisories...
New York...none.
Marine...none.

&&

$$

Synopsis...apffel/Hitchcock

National Weather Service Glossary of Abbreviations