Ohio, Pennsylvania, New York and much of the Northeast braced for severe thunderstorms and possible tornadoes on Thursday.

The National Weather Service warned that multiple states were threatened by destructive weather through the evening.

New Yorkers prepared for a derecho that experts warned could possibly hit the region. The meteorological phenomenon is described by the Storm Prediction Center as a "widespread, long-lived wind storm that is associated with a band of rapidly moving showers or thunderstorms ... By definition, if the wind damage swath extends more than 240 miles and includes wind gusts of at least 58 mph then the event may be classified as a derecho."

Elmira, New York, saw a possible tornado touch down, as a storm reportedly damaged a nearby mall and country club.

In Ohio, storms swept across the state, with reports of hail and trees downed, according to the Columbus Dispatch. The Associated Press reported that the storm shut down rides at the annual State Fair, with visitors encouraged to take shelter. The news organization adds that as of late afternoon, at least 12,000 customers have lost power to the storms.

Local Pennsylvania officials reported possible tornado sightings near Brookville and Barnett, with the National Weather Service issuing tornado warnings for specific regions of the state. An alert issued at 4pm EDT read: "SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS!" The warning asked residents to report hail and damage to the National Weather Service by calling toll free: 1-877-633-6772.

The National Weather Service offers this advice for surviving a tornado:

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS. IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

This isn't the first case of extreme weather to sweep the U.S. this season. Heat waves and severe drought have plagued regions of the country, leading many to connect potential dots between some weather patterns and climate change.

Visit the National Weather Service website for updates on the most recent storms threatening your area.

Click here for updated information.

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@ lheron : Awesome (in the terrifying sense) #nyc #derecho storm photo by @isardasorensen: http://t.co/hDNHgopA cc @wsjweather

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@ BuzzFeedAndrew : Lower Manhattan as seen from New Jersey. http://t.co/d7DRP2rW

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@ AC360 : #AC360 staff momentarily distracted by this outside our window: http://t.co/r063uSS9 NYC storm #Derecho

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@ severewarn : Severe Thunderstorm Watch for portions of the area in WV until 10:00pm EDT. #wvwx

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@ wkycweather : Forecast... Cleveland Weather: We aren't done yet http://t.co/GY1Z55YJ #Weather_Forecast #wkycweather

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@ MayorMark : Danbury 10 year olds stopping game to take shelter. #Danbury

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@ DarrenSweeney : The bowing I'm seeing on the radar tells me some big, widespread wind is likely especially in SW CT,awnings up lawn furniture in! #ctweather

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@ CTDEMHS : FLOOD WATCH STILL IN EFFECT FOR HARTFORD, TOLLAND AND WINDHAM COUNTIES

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@ wtaptelevision : Storms Shut Down Operations At Ohio State Fair: A powerful storm rolling through Ohio has shut down operations a... http://t.co/3c8gNSpm

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@ WxBeck : Thunderstorms are now spanning a line approximately ~2000 miles, from Texas, northeast to the bow moving into NYC. Impressive storm day.

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Storms have brought several inches of rain to Summit and Medina counties in Ohio, reports WKYC.

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@ TWCBreaking : A new #severe thunderstorm watch until 1am EDT for all of #Delaware, most of #Maryland, northern #Virginia, eastern #WV, and #DC

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@ Doppler10 : Another storm has popped up to the southwest of Marysville, Ohio. There's another one to the northwest. Follow... http://t.co/PxCQ06Y2

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@ nbc40weather : Severe thunderstorm watch for all of South Jersey now until 1am...included are Atlantic, Cumberland, Cape May, and Salem counties.

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@ EricFisherTWC : First Energy reporting nearly 100k customers without power in Pennsylvania alone. More to come around the region. #PAwx

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@ EricFisherTWC : From Bradford County: Massive reports of trees/branches with wires down but no reported structural damage. Lost one radio tower. #PAwx

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@ twcMariaLaRosa : Amazing solid line of warnings with this monster squall line; includes #NYwx #PAwx #WVwx #OHwx #severe @weatherchannel http://t.co/S4WO3JMF

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@ WSAZKari : Storm already hit my cousin's house up in northern Ohio. High winds!! Cable knocked out.

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@ usNWSgov : #Tornado impacts #Elmira, #NY, damaging the Arnot Mall and Elmira Country Club with people trapped in vehicles. #nywx

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Clouds move in over Geneva, Ohio, reports WKYC.

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@ severewarn : Severe Thunderstorm Warning for Athens, Gallia, Jackson, Meigs, Morgan, Vinton and Washington County in OH until 6:15pm EDT. #ohwx

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@ NYGovCuomo : Reports of significant damage in Elmira, possible tornadic activity, state assessment crews on the way #stormwatch

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@ mikeseidel : Per Chemung County, NY Emergency Management: Report of a Tornado Elmira Buildings Destroyed Houses on fire People trapped Unknown injuries

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@ IrishEagle : 2 pics out of Elmira, NY: http://t.co/jgVNkIS3 http://t.co/0Hw3bCCu #nywx

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@ usNWSgov : #Tornado impacts #Elmira, #NY, damaging the Arnot Mall and Elmira Country Club with people trapped in vehicles. #nywx

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@ breakingweather : 56,000 currently without power across Pennsylvania

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@ breakingweather : 23,000 customers are without power across the state of Ohio.

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@ breakingstorm : Report of storm damage to mall, country club in Elmira, New York - @usNWSgov

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@ usNWSgov : #Severe Tstorm Watch 524 in effect until 10pm EDT for portions of #IN, #KY #MD, #NY, #OH, #PA and #WV. http://t.co/kCPjwUtJ | #NWS #SPC

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