Rochester, New York 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

655
FXUS61 KBUF 201054
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
654 AM EDT Sun Jul 20 2025

.SYNOPSIS...
A cold front slowly moving through from the north will result in
some shower and thunderstorm activity across the region through the
early afternoon. Much cooler and quieter weather will then prevail
through Monday night. Summer heat and humidity begin to ramp up in
the second half of the week with increasing chances for unsettled
weather.

&&

.NEAR TERM /THROUGH TONIGHT/...
Low amplitude troughing centered over northern Quebec will pivot and
dig across the Northeast through the period. A wave of sfc low
pressure slowly moving through the Eastern Great Lakes will be
followed by a cold front from the north later this morning into the
early afternoon.

Convection along the main sfc trough axis this morning should
continue to weaken over Lake Ontario before sliding east into the
North Country. Coverage should remain more uneven across WNY this
morning, though as SBCAPE values increase to around 1000J/kg with
daytime heating ahead of the boundary some intensification could
occur across the Finger Lakes and/or interior Southern Tier. Behind
this round of convection, a localized zone of convergence as the
front encounters some backed SW flow across Lake Erie may also cause
additional shower/thunderstorm development across WNY, though
confidence in this occurring is low. The majority of the convective
activity will depart the region to the southeast by early to mid
afternoon.

Strong CAA with 850H temps dipping down into the mid/upper single
digits (C) by tonight combined with brisk NNW flow will translate to
a cooler night with strato-cu developing. A few upslope enhanced
light showers/sprinkles will be possible, particularly in the Finger
Lakes region overnight.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
During this period broad upper-level troughing across the Great
Lakes and Northeast on Monday will give way to rising heights
Tuesday and Wednesday as upper-level ridging over the south-central
CONUS builds across the central Mississippi Valley. Meanwhile at the
surface...Canadian high pressure initially centered near James Bay
on Monday will slowly drift southeastward to New York State and New
England through Tuesday night...then off the New England/mid-
Atlantic coastlines Wednesday.

All this will result in something we haven`t seen much of this
summer...a multi-day period of fair dry weather areawide. Cool air
aloft (850 mb temps of +6 to +10C) attendant to the upper trough and
Canadian surface high will result in highs only reaching the upper
60s to lower 70s in most spots on Monday...with day-to-day airmass
modification and (eventually) a developing southerly return flow of
warmer air then allowing highs to climb back to the mid-upper 80s in
most areas by Wednesday. Meanwhile humidity levels will be quite
comfortable both Monday and Tuesday...before climbing back to
moderately sticky levels by later Wednesday and Wednesday night.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
Midsummer heat and humidity will return in full force by Thursday as
the core of the upper ridge slides eastward across the Lower Ohio
Valley and Virginias...with associated subsidence and continued warm
advection in between the departed surface ridge and a slow-moving
frontal boundary over Ontario/Quebec helping to pump 850 mb temps up
into the vicinity of +20C. This should translate into highs in the
upper 80s to lower 90s in many areas...with a few of our normal warm
spots possibly reaching the mid 90s. Coupled with surface dewpoints
surging to around 70F...this may result in apparent temperatures
reaching the 95-100 range from portions of the Niagara Frontier/
Genesee Valley eastward to Oswego county. Otherwise the day should
be largely dry...with just a low chance for some widely scattered
afternoon convection as the aforementioned frontal boundary begins
to slowly sag southward.

Friday and Saturday the upper ridge will flatten and get shunted
southeastward in response to shortwave energy rippling eastward
along the Canadian border...with the latter helping to push the
surface front southward and (eventually) across our region...though
the medium range guidance suite continues to exhibit differences
with respect to just how quickly the front pushes southward. In
general this should lead to an increased potential for showers and
thunderstorms Thursday night through Friday night...with pcpn
chances potentially lingering into Saturday depending upon the
southward progression of the cold front. Otherwise it should remain
rather warm and quite muggy Friday...with a nominal reduction in
temps/humidity levels then following for Saturday.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
A wave of sfc low pressure moving east through the region will be
followed by a cold front from the north today. A period of MVFR cigs
is expected along and immediately behind this front with scattered
areas of showers and embedded thunderstorms. Brief MVFR and
localized IFR vsbys in thunderstorms cannot be completely ruled out
at any one location though this risk sharply decreases for the TAF
sites after about 17z. Cigs should improve to mainly VFR and scatter
out behind the front later this afternoon.

Cold air advection and northerly flow may result in additional
strato-cu and some widely scattered showers south of most of the TAF
sites tonight. Cigs may be low enough across the higher terrain
areas (KJHW) to cause MVFR though VFR should prevail further north.

Outlook...

Monday through Wednesday...VFR...with localized river valley fog/IFR
possible each late night and early morning.

Thursday...MVFR/VFR with showers and thunderstorms possible.

&&

.MARINE...
A cold front will slowly move across the Lower Great Lakes later
this morning and afternoon, with Canadian high pressure building in
its wake. Showers and embedded thunderstorms are expected over Lake
Ontario this morning ahead of the front.

West/southwesterly winds this morning will turn northerly and then
increase on both lakes later this evening and through tonight behind
the front. Marginal SCA conditions could be briefly achieved on Lake
Erie during this timeframe, though will more solidly reached on the
eastern half of Lake Ontario.

The decreasing pressure gradient as the high moves further into the
Great Lakes region will cause winds to relax later Monday morning.
Sub-SCA conditions are then expected on both lakes through much of
the week.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory from 8 PM this evening to 8 AM EDT Monday
         for LOZ043-044.

&&

$$

SYNOPSIS...PP
NEAR TERM...PP
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...PP
MARINE...PP