Flood — Morris, New Jersey

2014-05-01 to 2014-05-06 · near Chatham, Morris, New Jersey

Event narrative

Very heavy rain caused poor drainage flooding as well as minor to moderate flooding in the Passaic Basin beginning on April 30th. Some of the flooding along the Passaic River did not start until May 1st. In Roxbury Township, the exit ramps in both directions off of U.S. Route 46 were flooded and closed. The heavy rain forced emergency repair lane closures on Interstate 287 in Parsippany-Troy Hills and Morristown. Mass transit was not immune. Service was suspended along a section of New Jersey Transit's Montclair-Boonton Line until May 5th as workers repaired a track washout. Buses were made available to shuttle passengers between Montclair State University and Denville. The flooding washed away the stones that support the rails between Boonton and Towaco stations early on May 1st. The Passaic River flooded sections of Long Hill Township and Chatham. Some roadways remained closed into May 2nd.

The Passaic River at Chatham had minor flooding and was above its 6 foot flood stage from 637 p.m. EDT on April 30th through 515 a.m. EDT on May 1st. It crested at 6.46 feet at 815 p.m. on April 30th. The Pequannock River at the Macopin Dam had minor flooding and was above its 5.5 foot flood stage from 1120 p.m. EDT on April 30th through 1130 a.m. EDT on May 2nd. It crested at 6.07 feet at 155 p.m. EDT on May 1st. The Whippany River at Morristown had minor flooding and was above its 6 foot flood stage from 711 p.m. EDT on April 30th and 700 a.m. EDT on May 1st. It crested at 6.37 feet at 1100 p.m. EDT on April 30th.

The Passaic River at Millington had minor flooding and was above its 8 foot flood stage from 7 a.m. EDT on May 1st through 445 a.m. EDT on May 3rd. It crested at 8.24 feet at 730 p.m. EDT on May 1st. The Passaic River at Chatham had a second round of minor flooding with a slightly lower crest. The river was above its 6 foot flood stage from 130 p.m. EDT on May 1st through Noon EDT on May 4th. It crested at 6.34 feet at 600 a.m. EDT on May 2nd. The Passaic River at Pine Brook had moderate flooding and was above its 19 foot flood stage from 120 p.m. EDT on May 1st through 845 a.m. EDT on May 6th. It crested at 20.23 feet at 300 p.m. EDT on May 2nd. Lastly, the Passaic River at Two Bridges had minor flooding and was above its 9 foot flood stage from 345 p.m. EDT on May 1st through 730 a.m. EDT on May 6th. It crested at 10.76 feet at 330 a.m. EDT on May 3rd. The Rockaway River below the Boonton Reservoir had minor flooding and was above its 5 foot flood stage from 120 a.m. EDT on May 1st through 300 a.m. EDT on May 3rd . It crested at 6.62 feet at 330 p.m. EDT on the 1st.

Event precipitation totals included 4.89 inches in Chatham, 4.74 inches in Florham Park, 4.70 inches in Madison, 4.58 inches in Chester Township, 4.56 inches in Long Hill Township and 4.53 inches in Morris Township.

Wider weather episode

A slow moving low pressure system and a deep southerly flow from the Gulf of Mexico and then the Atlantic Ocean dropped heavy rain across New Jersey centered on April 30th. Event precipitation totals averaged from 3 to 6 inches, with the highest amounts in central New Jersey. This caused widespread poor drainage flooding as well as flooding of creeks and rivers throughout most of the state. Flooding in parts of the Passaic Basin and southeast New Jersey did not start until May began. Major creek and river flooding occurred in the Raritan and Assunpink Basins with moderate river flooding occurring in parts of the Passaic Basin. Many roadways were flooded. New Jersey Transit cross honored tickets on the commuter rail lines and buses. One hundred forty-six major roadways and interstates were flooded and completely closed or had lane closures throughout the state of New Jersey. Many roadways were re-opened by the end of the day on May 1st and most were opened again on May 2nd. The steady rain started during the afternoon of April 29th and fell at a steady light to moderate clip through the night. But, on April 30th the rain fell heavy at times during the morning and afternoon in the southern third of the state, and from the late morning into the evening of April 30th elsewhere in the state. Rainfall amounts of 2 inches in six hours were common. The rain ended from the south to north from around Midnight EDT to around 6 a.m. EDT on May 1st.

The heavy rain was caused by the combination of a strong high pressure system that built over the Canadian Maritimes that initiated the onshore flow and a strong, but slow moving low pressure system. The low pressure system was located in northwest Missouri on the morning of April 29th. It moved northeast to near Chicago during the afternoon of April 29th. The low pressure system then became nearly stationary in southern Wisconsin as its cold front reached Ohio early on April 30th. Then a new low pressure system developed on the frontal boundary and was over Eastern Tennessee on the morning of April 30th. The low pressure system reached West Virginia during the late afternoon on April 30th as its warm front started to move through Delmarva. The low pressure system reached north central Maryland at 11 p.m. EDT on April 30th as its warm front reached extreme southeast Pennsylvania and central New Jersey. The low pressure system reached the Allentown, Pennsylvania area at 5 a.m. EDT on May 1st and then was absorbed again into the frontal boundary associated with the original low as it moved into New York State that morning. The steady rain ended as the low pressure system passed north of New Jersey. But the formation of the second low pressure system and the passage of the warm front helped veer the winds from the east to the southeast and enhanced the surface flow that produced the coastal flooding along the tidal Delaware River.

View location on OpenStreetMap → (40.7164, -74.3911)

Source: NOAA Storm Events Database, event_id 518361. Narrative written by the NWS forecast office that issued the report.