October 4-7, 2013 Severe Weather
A prolonged storm system affected the eastern half of the US between October 4-7, starting with an unseasonably early blizzard in North Dakota, with the cold front then slowly tracking east until reaching the northeast US on October 7, producing a strong squall line with heavy rain and thunderstorms, marking the only notable rain event during the month, and even spawning an EF-1 tornado over Paramus, NJ despite an otherwise inactive severe weather season in 2013.
October 7, 2013 Storm Archive
October 3 – Rain Finally Returns Next Week
October 4 – Brief Update
October 6 – Rain Returns This Week
October 7 – Heavy Rain, Storms, Wind Today
October 7 Storm Updates
The low pressure originated in the western Plains region on early Friday, October 4, with a minimum pressure near 1006 mb. The low continued to slowly track to the north as the trough became negatively tilted, later stalling for a short period of time over eastern North Dakota on Saturday morning, October 5. This led to a long duration heavy wet snow event over western North Dakota, with snow totals over 24-30 inches observed. With the low pressure becoming occluded by that point, precipitation weakened as the system began to gradually track east through Minnesota and Wisconsin. A Canadian trough then dived southwards and picked up the upper level low, which then opened up as the strong shortwave moved through Ohio into NY state, while the surface low pressure quickly tracked northeast into Canada on October 7 while the cold front slowly pushed east through the northeast US region, weakening later into the day as the strongest forcing lifted north into Canada.
Forecasting The Storm
This section will be added soon.
Storm Impact in the Northeast
Radar image from 3:28 PM on Monday, October 7, showing the squall line moving through the region; northeast NJ was in the southern end of the main squall line around the time a tornado formed over Paramus, NJ. Radar images from the National Weather Service.
Up until October 7, the northeast US region has been much drier than average with developing drought conditions; the last significant rain event prior to this event was on September 12. The cold front entered western parts of the region on Monday morning, October 7, with heavy thunderstorms developing along the front end of the line around 10-11am from Virginia through central PA and NY, holding together until reaching eastern Pennsylvania by 1pm. At that point, with the strongest forcing lifting north into NY state and Canada, the squall line became more broken south of central NJ, with heavy thunderstorms holding together over NY state, where heavy rain up to an inch and damaging wind gusts were reported with a strong low level jet over the region.
Despite the squall line falling apart near New Jersey, the southern end of the main squall line was located over northern NJ, with the line reaching western NJ by 2pm, north central NJ by 3pm, and NYC by 4pm. As the squall line brushed northeast NJ, an EF-1 tornado briefly developed over Paramus, NJ between 3:16pm and 3:18pm. With the strongest forcing over Canada, the cold front and squall line continued to weaken while moving east through NYC, with only scattered showers reaching Long Island and Connecticut by 5pm, with rain ending by 5-7pm from west to east.
Storm Rain Totals
Estimated rain total maps will be added into the storm archives later in 2014.
The storm was notable for producing the only widespread rain event in October in the NYC area, with 0.25 inch of rain in Central Park; following storm systems later in the month stayed south, such as October 9-11 which was initially forecast to produce widespread heavy rain but instead remained south of the area. The total precipitation for October was 0.36 inch, making it the 3rd driest October and 11th driest month on record in Central Park while offering little relief from the developing drought. More widespread heavy rain totals stayed west and north of the area, with up to 1 to 1.5 inch of rain from Maryland into central PA and central NY states. Despite an otherwise inactive severe weather season in 2013, the squall line was responsible for spawning an EF-1 tornado over Paramus, NJ, with wind speeds up to 100 mph. Below is the statement on the tornado from the National Weather Service at Upton, NY:
...TORNADO CONFIRMED NEAR PARAMUS IN BERGEN COUNTY NEW JERSEY... LOCATION...PARAMUS IN BERGEN COUNTY NEW JERSEY DATE...OCTOBER 7 2013 ESTIMATED TIME...316 PM - 318 PM EDT MAXIMUM EF-SCALE RATING...EF1 ESTIMATED MAXIMUM WIND SPEED...100 MPH MAXIMUM PATH WIDTH...100 YARDS PATH LENGTH...1.25 MILES BEGINNING LAT/LON...40.9317N / 74.0926 W ENDING LAT/LON...40.9459 N / 74.0779 W * FATALITIES...0 * INJURIES...0 * THE INFORMATION IN THIS STATEMENT IS PRELIMINARY AND SUBJECT TO CHANGE PENDING FINAL REVIEW OF THE EVENT(S) AND PUBLICATION IN NWS STORM DATA.