Area Forecast Discussion
Issued by NWS Buffalo, NY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 261925

Area Forecast Discussion
National Weather Service Buffalo NY
325 PM EDT Sun Mar 26 2017

A weak system will move northeast through the Great Lakes region
tonight with another round or two of rain along with some
embedded thunderstorms. Some rain may last into Monday, but in
general expect drying trend. Another relatively weak system will
move through on Tuesday. Drier and cooler weather will arrive
for Wednesday and Thursday. Showers will return Friday and last
through the weekend.


The upper level pattern over the US features a cutoff low near
Chicago this afternoon with another one on its heals near the TX
panhandle. Both are embedded a broad but weak upper level
longwave ridge and will therefore have minimal impact over
Western and Central NY over the next few days, although both
will bring some short-lived periods of rain and the possibility
of thunderstorms

Through tonight...the main concern is focused over the Chicago
low with a weak surface reflection. There are three troughs
rotating around this low. The first of the three troughs will
move through this evening and will be denoted as a warm front.
But, surface temperatures will vary little with its passage with
most of the warmth remaining aloft while the surface remains
under an inversion. There may be some convection with this
boundary as they move into Western NY, but the thick inversion
should keep any winds aloft from mixing down to the surface.
Winds aloft max are not too impressive anyway as they max out at
about 40kts. The 2nd trough will follow quickly with a similar
scenario - a band of showers with the possibility of
thunderstorms over WNY. Both band should continue ENE overnight
and weaken a little with a diminishing threat for thunderstorms
toward Central NY.

Despite the inversion, temperatures climbed to 60F in the
downslope area of WNY while other areas remain in the 40s or
lower 50s this afternoon. Some of this warmth will be lost as
the inversion strengthens together with the loss of daylight,
but overall expect a relatively warm night - mostly in the
40s...a little cooler toward the Eastern Lake Ontario region.

Monday...the third trough marks the cold front. This feature
should be rather weak as a result and may come through dry or
only with some scattered showers sometime on Monday. The front
erase the warm air aloft, but at the surface expect little
temperature variation from the front itself. In fact with some
mixing, temperatures should again climb into the 50s across most
areas, and touching the 60F mark over downslope regions south
of Lake Ontario (but away from the shoreline).


While initially dry Monday evening, as a narrow ridge of high
pressure moves across the region, late Monday night into Tuesday
morning will see increasing coverage of rain showers as an open
trough tracks through Ohio Valley to off the northeast coast by
Tuesday afternoon. This will result in a few hours of showers moving
across the region, with a drying trend from west to east across the
region by Tuesday afternoon. Increased PoPs to categorical, with
most all locations picking some light rain on Tuesday, however it is
important to stress that Tuesday looks to be far from a washout,
with plenty of dry time as showers taper off. Highs on Tuesday will
range from the upper 40s in the North Country to the upper 50s in
the Southern Tier as cooler air moves in from the north behind the
trough passage.

Tuesday night through Thursday will finally bring a stretch of dry
weather to region as a sprawling high pressure system builds in
across the Great Lakes. Temperatures will moderate to near seasonal
normals, with highs mainly in the 40s and low in the 20s/30s.


The pattern will become more active again by the end of the week
after a few dry days. A mid level closed low will meander across the
Four Corners region during the first half of the week, then eject
ENE across the central Plains to the Ohio Valley by Friday.
Increasing warm advection and moisture transport ahead of this
trough will bring a chance of a few showers Thursday night mainly in
Western NY. Rain chances will then increase Friday and Friday night
as the deep mid level trough and associated surface low cross the
region. The system will be filling with time, which generally keeps
forcing and moisture transport on the weaker side which will in
turn keep rain amounts relatively modest.

This system will slowly pull out next weekend, with a few scattered
showers lingering into Saturday as the trough and surface low move
to the east coast, with northwest flow and wrap around moisture
hanging back across the Lower Great Lakes. Moisture and rain chances
should diminish by Sunday as the trough moves well off the eastern

Temperatures will likely run a little above average through the
period, with highs generally in the low to mid 50s and lows in the


one or two bands or showers with some thunderstorms will move
toward far Western NY late this afternoon from the OH valley.
Expect a broken line or lines to continue moving across the
Genesee Valley and into the Eastern Lake Ontario region
overnight. There will be an increasing chance for MVFR and some
IFR conditions from CIGS with the passage of these
showers...particularly in the hilly terrain toward the PA
border. Expect a decreasing chance for showers on Monday with
slowly improving conditions to VFR areawide.


Tuesday...MVFR/IFR cigs with periods of rain.
Wednesday and Thursday...VFR.


Winds will veer to southeast and then southerly as an area of
low pressure tracks across the central Great Lakes and towards
NW Lake Ontario. As these winds veer, they will increase some on
the eastern half of Lake Ontario, such that low end SCA wind
thresholds will be met and last through tonight.

The relatively weak low will move northeast of Lake Ontario
Monday, and in its weaken state, and warm air over the cold lake
waters, both winds and waves should remain below SCA criteria.


MARINE...Small Craft Advisory until 11 PM EDT this evening for LOZ042-
         Small Craft Advisory until 8 AM EDT Monday for LOZ044-045.



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