Editor's note: This story was updated on July 10, 2019.
At least 33 tornadoes have hit Pennsylvania since the beginning of the year, according to the National Oceanic and Atmospheric Administration (NOAA).
Fifteen of those tornadoes occurred in May.
Thirteen of those occurred in one week.
According to the National Weather Service, the 33 tornadoes -- so far -- in 2019 makes it the third-highest number on record.
1998 saw the most, with 61.
Note: Some meteorologists say that there have been 34 tornadoes in Pennsylvania, but the National Weather Service confirms only 33.
Tornadoes occur most frequently in April, May and June in Pennsylvania.
Pennsylvania typically averages 16 tornadoes for an entire year, according to research from NOAA.
"Of course, mid-Spring into mid-summer is our 'severe weather season,' so some T-storm threats is normal, but it’s been unusually active for sure this year," said Millersville meteorologist Eric Horst.
"The jet stream off the Pacific has been unusually strong the last few months due to enhancement by the El Nino ongoing in the Pacific—so this is a factor." said Horst.
Horst also said that the pattern of severe weather will likely continue for a little while yet.
How are tornadoes measured?
Meteorologists use the Enhanced Fujita Scale to correspond winds with a score. Sometimes, winds can be hard to measure in the peak of a tornado, so sometimes the amount of damage caused by the tornado will act as an indicator of how fast the winds were.
EF-0: 65-85 miles per hour
EF-1: 86-110 miles per hour
EF-2: 111-135 miles per hour
EF-3: 136-165 miles per hour
EF-4: 166-200 miles per hour
EF-5: 200+ miles per hour
Where tornadoes touched down in Pennsylvania in 2019:
NNE of New Lebanon, Mercer County, EF-1
Springboro, Crawford County, EF-0
SE of Cooperstown, Venango County, EF-0
NE of Cherrytree, Venango County, EF-0
Starbrick to Scandia, Warren County, EF-2
Buffalo Valley, Union County, EF-1
Benton, Columbia County, EF-2
Dushore, Sullivan County, EF-1
Scranton, Lackawanna County, EF-0
Harford Township, Susquehanna County, EF-1
Knobsville, Fulton County, EF-1
St. Thomas, Franklin County, EF-2
Richvale, Huntingdon County, EF-1
Krause, Juniata County, EF-1
Lewistown, Mifflin County, EF-2
West Cocalico Township, Lancaster County, EF-1
Ottsville, Bucks County, EF-1
Westmont, Cambria County, EF-0
Burrell Township, Indiana County, EF-1
Homer City, Indiana County, EF-0
Caernarvon Township near Morgantown, Berks County, EF-2
Wysox Township, Bradford County, EF-1
Newton Township, Lackawanna County, EF-1
Penn Run, Indiana County, EF-0
Losh Run, Perry County, EF-1
Border of Bucks, Lehigh counties, EF-0
Matamoras, Dauphin County, EF-1
Falls Township, Wyoming County, EF-0
Dushore, Sullivan County, EF-0
Wells Tannery area, Fulton County, EF-1
Sharon, Mercer County, EF-1
Parker, Butler and Armstrong Counties, EF-1
Commodore, Indiana County, EF-1