Area Forecast Discussion
Issued by NWS Buffalo, NY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

FXUS61 KBUF 201853

Area Forecast Discussion
National Weather Service Buffalo NY
253 PM EDT Wed Sep 20 2017

Warm temperatures and dry conditions will persist through the
remainder of the week and the coming weekend, as high pressure will
remain in place across the region.


It is yet another sunny and warm afternoon across the forecast area
this afternoon, as the nuisance marine stratus layer off of Lake
Ontario has finally mixed out. It will be a sunny end to the day for
all areas, with clear skies this evening.  The clear skies and light
winds will set the stage for another foggy night for many areas
later tonight and into early Thursday morning, particularly in
river valleys and near lakes/ponds. With ideal conditions for
radiational cooling and slightly lower dewpoints, we should see
cooler temperatures as compared to Tuesday night, with lows in
the 50s, with a few lower 60s near Lake Erie.

Thursday will be another near carbon-copy of today with perhaps the
only differences being the mid-level ridge strengthening to 588dm
and 850mb temps warming a degree to +17C. The high pressure surface
and aloft will keep dry and warm weather in place with high temps
again warming into the low to mid 80s or 10-15 degrees above normal
September levels. Dewpoints holding in the 60s will keep a humid
feel to the airmass.


The calendar will remain turned back a couple months through this an anomalously strong 590dm sub tropical ridge will
remain anchored over the Ohio Valley and Lower Great Lakes. This
prodigious ridge will be accompanied by equally exceptional warmth.

H85 temps tat will start off in the mid teens C Thursday night will
further warm to the upper teens C for the weekend. This will
encourage additional day to day warming so that by Saturday...max
temps will be in the mid to upper 80s F. Given the increasingly dry
antecedent conditions...its not out of the question that select
locations in the Genesee Valley (ie. Dansville) and in the typically
warmer valleys of the Southern Tier would reach 90. If this were mid
summer (when the sun angle would be more than 20 deg greater) then
we would possible be talking about some oppressive heat. Luckily for
us...the Gulf of Mexico will be cut dew points that will
start off in the upper 50s to lower 60s will not climb past 65 by
late in the weekend.

Meanwhile the nights will feature mainly clear skies with the
resulting favorable radiational cooling producing fog in open...
outlying areas...and particularly in the Southern Tier valleys. Mins
will range from the mid and upper 50s across the Southern Tier and
parts of the North Country to the low to mid 60s across the lake


A very high confidence forecast remains in place for the
unseasonable warmth to continue during this three day a
high amplitude ridge will remain intact across the eastern third of
the country. The only problem will be the possible effects from
Hurricane Maria...which by Wednesday will likely be churning
northward of the mid Atlantic coast. While the ridge will keep us
rain free through at least Tuesday...there have been some medium
range ensembles that are suggesting that some Atlantic moisture
could work back across the region late Tuesday night and Wednesday.
From this vantage point though...the odds favor continued dry
weather...but will introduce slgt chc pops as we end the seven day


Stratus coming off of Lake Ontario has finally mixed out this
afternoon, leaving widespread VFR skies in place across the forecast
area. Expect VFR conditions to prevail through the evening hours,
however with high pressure, light winds, and clear skies in place
tonight, expect fog to redevelop again tonight after 03-06Z. Similar
to last night, IFR/LIFR conditions are expected at KJHW/KROC and
potentially KIAG. KART may escape the fog tonight, as synoptic NE
flow may be strong enough to keep the lowest levels mixed - however
should the wind drop off later this evening, then fog formation is
likely. IFR/LIFR conditions will rapidly improve after 12-13Z on
Thursday, with another VFR day on tap for the area, as high pressure
will remain in place.


Thursday night through Tuesday...VFR. Local IFR conditions each late
night and early morning with fog.


High pressure will remain in place across the Lower Great Lakes
right through next weekend. This will provide a long stretch of very
light winds and flat wave action for the rest of the week and
weekend with ideal boating conditions, but not much wind for sailing.





MARINE...HITCHCOCK/THOMAS is the U.S. government's official web portal to all federal, state and local government web resources and services.