When it lasts until and how strong the winds will be vary according to where you are..
Erie & Niagara Counties: until 4 pm Friday, with 30- 40 MPH winds and gusts as high as 60 MPH
Chautauqua County: until 2 pm, with higher gusts expected along the Thruway to Lake Erie, and across higher terrain.
Orleans, Genesee & Wyoming: until 5 pm Winds: Southwest 30 to 40 MPH, with gusts up to 60 MPH
Regardless of where you are, the weather service says winds of this magnitude may bring down some trees and powerlines resulting in scattered power outages, and could also make for difficult travel in high profile vehicles.
Verbatim from the National Weather Service;
URGENT - WEATHER MESSAGE NATIONAL WEATHER SERVICE BUFFALO NY 450 AM EDT FRI NOV 1 2013 NYZ001-010-085-011700- /O.CON.KBUF.HW.W.0003.000000T0000Z-131101T2000Z/ NIAGARA-NORTHERN ERIE-SOUTHERN ERIE- INCLUDING THE CITIES OF...NIAGARA FALLS...BUFFALO... ORCHARD PARK...SPRINGVILLE 450 AM EDT FRI NOV 1 2013 ...HIGH WIND WARNING REMAINS IN EFFECT UNTIL 4 PM EDT THIS AFTERNOON... * LOCATIONS...ERIE AND NIAGARA COUNTIES. * TIMING...THROUGH LATE THIS AFTERNOON. * WINDS...SOUTHWEST 25 TO 35 MPH WITH GUSTS UP TO 60 MPH. * IMPACTS...WINDS OF THIS MAGNITUDE MAY BRING DOWN SOME TREES AND POWERLINES RESULTING IN SCATTERED POWER OUTAGES...AND ALSO MAKE FOR DIFFICULT TRAVEL IN HIGH PROFILE VEHICLES. IN ADDITION... HOLIDAY DECORATIONS AND OTHER LOOSE OUTDOOR ITEMS SUCH AS TRASH CANS MAY BE BLOWN AWAY. PRECAUTIONARY/PREPAREDNESS ACTIONS... A HIGH WIND WARNING IS ISSUED WHEN SUSTAINED WINDS OF 40 MPH ARE EXPECTED FOR AT LEAST AN HOUR...WITH GUSTS OF 58 MPH OR GREATER AT ANY TIME. DAMAGE TO TREES...POWER LINES...AND PROPERTY ARE POSSIBLE WITH WIND OF THIS MAGNITUDE. IF YOU HAVE A HIGH PROFILE VEHICLES BE EXTRA CAREFUL UNTIL THE WIND SUBSIDES.