1998 April Fool's Day Tornadoes

As a cold front was moving into western PA during the morning hours, a line of showers and thunderstorms developed, basically along the frontal boundary. At this time (1335Z, or 835 am), the storms were not severe, but needed to be watched for further development.

Dew points were in the 50's to low 60's that day, with temperatures in the 60's.

As the thunderstorms moved east, across Blair and Centre counties, they weakened slightly, as shown in this 1430Z (930am EST) base reflectivity radar shot. However, over the next hour and a half, by 1600Z, the storms strengthened, with the strongest cells over south central Centre county and Huntingdon county. The storms continued to intensify as they moved toward the Susquehanna valley. By 1724Z, this 4-panel radar picture showed a mini bow-echo starting to develop over Union & Snyder counties. This bow then proceeded to move east, across northern Northumberland and Montour counties. At 1740Z, the storm velocity data suggested cyclonic shear over extreme northeastern Northumberland county (a few miles to the NW of where I live!) For the people who are not familiar with reading this map, let me explain. The green colors show inbound winds, and the red, outbound winds. Note the green inbounds in the Muncy area, and the red outbounds just north of Milton.

The bow-echo produced downburst and tornadic damage in northern Montour county. The strange thing about this event, is that the bow-echo formed many miles to the west, over Union and Snyder counties, but didn't produce ANY damage until it reached northern Montour county. Even then, the damage was in a very small area. This is unusual of bow-echoes, as they are usually associated with widespread wind damage.

Now that we saw how the event came together on radar, let's look at the damage.

A thunderstorm in the bow-echo produced a downburst just north of the route 44 & 54 intersection in northern Montour county. The damage was a combination of a downburst and a gustnado. It appears that the gustnado spun up along the leading edge of the downburst. The damage would indicate that there were two gustnadoes in the beginning, that then merged into one. The damage path was just over 2 miles long, and at times, up to three quarters of a mile wide. There was one witness to the event, and his story shows how quickly and suddenly the wind hit. Between the radar images and his report, the damage time was placed at around 12:40 pm. He was watching the storm from his farmhouse, and noted that there was light rain occurring, for a time, and then it picked up in intensity, just as the winds increased very fast. A shed along side his house was destroyed. The roof of his house was blown off and hit a shed across the road, and a hay cart was blown into the same shed. Several other hay carts and manure spreaders were also moved by the wind, and a fiber glass calf crib was blown a 1/4 mile away. Another farm 1350 feet away had a tree down on his house, and a small barn was completely blown apart. An Amish buggy was blown northward, while a swing set was blown to the south, which indicates rotation. Siding from the house and barn was left to rest on the tops of trees about a 1/2 mile away. 2 miles down the road, another farm was damaged, much like the previous one. 1 more mile down the road, yet another farm experienced damage. The roof was blown off a small barn, and more hay carts and manure spreaders were thrown into farm buildings, damaging a tractor. A window was blown out of the main barn, which had 80 dairy cows in it. Amazingly, no cows were injured! The door from one of the barns was ripped off its rails and bent.

You can see a map of the direction the damage was blown here. A statement of some of the findings was also issued.

Another gustnado touched down in Adams county, this one rated an F1, with a path length of 1.5 miles and a width of 100 yards. It initially touched down around 12:30 pm, just south of Table Rock north of route 394, or about 5 miles to the northeast of Gettysburg. At the beginning of the damage path the weak tornado blew away a small chicken coup, and then tracked across an open field for a half mile. A horse watering trough and a bench were picked up and thrown. A fence was also knocked down. Toward the end of the storm path, a barn had its roof taken off, and another had its south side doors blown in, and its northside walls blown out. Several trees were also snapped. Nearby, a woman who used her house as a day care center, said she heard the severe thunderstorm warning and took the children to the basement.

Yet another tornado occurred in Chester county, this one also rated an F1. It touched down just west of PA highways 100 & 724, in Coventry township. The path length was one half mile, and the width 100 yards. The Coventry Mall and eight homes suffered damage, estimated at $25,000. A Pizza Hut Restaurant roof was also damaged. At the mall, the tornado pulled several doors open, and sucked out two clothing racks from a J.C. Penny store. Also, two steel power line towers were snapped, power poles were snapped, numerous trees were uprooted, a shed was destroyed, a 10'x25' privacy wall was damaged, and a large trash container was blown through a concrete retaining wall. As the tornado crossed PA SR 100, it hurled construction equipment and street signs, injuring one worker. One exit sign was found a half mile away. Two State Roads (SR) remained closed throughout the evening. The tornado narrowly missed the local Elementary school.

Thunderstorm winds uprooted trees and collapsed a shed in Lickdale, Lebanon county, around 1:30 pm. In Seipstown, Lehigh county, a severe thunderstorm tore the roof off of a garage, knocked over a support of the house's patio, and uprooted seven trees. In Morgantown, Berks county, a severe thunderstorm snapped the ropes tied to the wings of a Cessna airplane at the local airport, and moved it several feet. Thunderstorm winds were also responsible for ripping the aluminum trim from the roof of a building at the sewage treatment plant, tossing three 150 pound railroad ties, shattering the windows of a car, and overturning a large doghouse. Lightning struck at least three homes in Montgomery county, resulting in fire.

Between 2:30 & 2:40 pm, a severe thunderstorm moved from downtown Scranton to just east of Clarks Summit, including Scott and Greenfield townships. Several large trees were uprooted in the city of Scranton. Minor home damage was reported from falling tree branches. The minor damage included shattered windows, torn roof shingles, and gutters ripped off. At least 2 vehicles received minor damage from falling debris. Near Tompkinsville (north of Scranton), a small barn was flattened by thunderstorm winds, and a large falling tree did moderate to major damage to the porch area of a house. Damage estimates from the damage in Scranton and Tompkinsville were up to $40,000. Amazingly, a severe thunderstorm warning was NOT issued for this area... for unknown reasons. Luckily, there were no reported injuries.

In addition to wind damage, very heavy rain fell in some areas. This prompted the NWS in Mount Holly NJ/Philadelphia PA to issue flash flood warnings for Chester and Montgomery counties, at approximately 3:30 pm. SKYWARN spotters reported streams out of their banks, covering some roads.

Go here for a complete listing of all images/text available for this event.