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FXUS61 KBUF 171432

Area Forecast Discussion
National Weather Service Buffalo NY
1032 AM EDT Tue Sep 17 2019

Strong high pressure will provide us with a prolonged stretch of 
magnificent late summer weather for the rest of the week...with
temperatures climbing to well above normal by late in the week.


During this period the axis of sprawling surface high pressure will 
slowly drift from western Quebec and the Central Great Lakes to the 
Saint Lawrence Valley and eastern New York. Copious amounts of 
attendant dry air and subsidence will guarantee fair dry weather 
across our area along with mostly sunny/mainly clear skies...with 
the only real blemish on the forecast coming in the form of the 
usual Southern Tier valley fog later on tonight. As for 
temperatures...expect slightly above normal highs ranging from 
the upper 60s across the higher terrain to the lower to mid 70s 
elsewhere today. Lows tonight will then range from around 40 
across interior portions of the North Country to the lower 50s 
across the lake plains of far western New York.


...Magnificent Weather Through the Period...

An impressively persistent...high amplitude H5 ridge will be in 
place across the eastern half of the continent through this period. 
Its accompanying area of high pressure at the surface will be 
equally dominant in it will spend the majority of the 
time frame being sprawled over New England and the Mid Atlantic 
states. This will guarantee fair dry weather across our forecast 
area with subtle warm advection leading to steady day to day warming.

H85 temps that will start off between 8 and 10c will slowly warm to 
the mid teens by the end of the work week. This will allow some of 
the normally warmer areas (lake plains, valleys) to reach 80 by 
Friday afternoon. Overall...temperatures for the three day period 
will average a solid 5 degrees f above normal...with the greatest 
positive temperature departures being experienced each afternoon. 
This time period will prove to be ideal to do/complete any outdoor 
projects before the seasons really change.


High confidence remains in place during this period that 
temperatures will average well above normal. Temperatures are 
expected to average 10 to 15 degrees above seasonal levels during 
the weekend...with readings more typical of early August than late 
September. While the late summer warmth will fade somewhat on 
Monday...they will still be solidly above normal.

Supporting the warm weather will be a broad ridge that will be 
positioned over the eastern third of the country. A potent shortwave 
that is currently digging south along the coast of British Columbia 
though will make its way across the Canadian prairies by the 
weekend...and this feature will eventually push the impressive ridge 
out to sea. This will bring an end to the late summer warmth while 
introducing some showers to the region. Breaking this down on a day 
to day level...

Saturday should be the nicest day of the the H5 ridge 
axis will cross our region while its corresponding sfc high will be 
centered over the Mid Atlantic region. This will support a wealth of 
sunshine...and with H85 temps in the mid teens...we can anticipate 
afternoon highs to be in the 80s for all but the higher elevations.

As the surface high moves off the Mid Atlantic coast Saturday night 
and Sunday...a deepening southerly flow will advect moderately more 
humid air into our region. We can still expect clear to partly 
cloudy conditions though with another day featuring afternoon highs 
in the 80s.

By late Sunday though...some showers ahead of a pre frontal trough 
will near our region via southern Ontario. While the day should be 
rain free for the vast majority of the forecast area...a late day 
shower cannot be ruled out west of the Genesee Valley.

A pre frontal trough and subsequent cold front will then move 
through our region later Sunday night and Monday. This will support 
scattered showers...particularly on Monday.


During the TAF period the axis of the aforementioned area of high 
pressure will slowly drift from western Quebec and the Central Great 
Lakes to the Saint Lawrence Valley and eastern New York. This will 
result in widespread unlimited VFR conditions...with the only 
exception to this again coming in the form of the usual Southern 
Tier valley fog and attendant localized IFR conditions later on

Wednesday through Saturday...Mainly VFR...with localized 
IFR in Southern Tier valley fog possible each night/early morning.


High pressure will provide our region with light winds and minimal 
wave action for the rest of the week.






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