Flash Flood, Somerset
- When
- August 5, 2:00 PM EST to 4:00 PM EST
- Where
- Somerset County, Northeast Portion
- Reported by
- NEWSPAPER
- Coordinates
- 40.564, -74.616 (the zone’s center; the record gives no point)
Flash Flood in New Jersey, August 5, 2003
Thunderstorms with very heavy rain caused small stream and poor drainage flooding in the northeast part of Somerset County. Doppler Radar Storm total estimates were between 2 and 4 inches with the highest amounts in Watchung Borough.
Where it happened
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 1
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
What happened
The episode as NWS PHI wrote it up.
Thunderstorms with very heavy rain caused small stream and poor drainage flooding in the northeast part of Somerset County. Doppler Radar Storm total estimates were between 2 and 4 inches with the highest amounts in Watchung Borough. The worst reported flooding was in northern parts of Bound Brook Borough as both the Middle and Bound Brooks flooded. About 75 children from two day care centers were evacuated after the Middle Brook flooded. They were transported unharmed to Bound Brook High School. About ten roadways in Bound Brook were closed because of flooding including Main Street. Some lanes of U.S. Route 22 were also closed. Businesses and basements were flooded. Elsewhere in Somerset County, U.S. Route 22 was badly flooded in North Plainfield and Watchung Boroughs and there were several lane closures on Interstate 287 in Franklin Township.
What forecasters said that day
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Philadelphia/Mount Holly wrote its last area forecast discussion before the first event at Aug 5, 1:50 PM EST, 10 minutes earlier.
Area forecast discussion, Aug 5, 1:50 PM EST, 10 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 250 PM EDT TUE AUG 5 2003 THE UPPER TROUGH IS NOW COVERING THE FCST AREA...EMBEDDED SHORT WAVES WITHIN THE TROUGH WILL BE TRIGGERS FOR PCPN. WHEN THEY MOVE THROUGH DURING THE DAYLIGHT HOURS...THE HEATING OF THE DAY WILL ALLOW ANY DVLPG PCPN TO BE MORE WIDESPREAD THEN WHEN THE SAME SITUATION HAPPENS AT NIGHT. THE DIFFICULT PART OF THE FCST IS TIMING THE SHORT WAVES. THE ETA AND AVN HAVE DIFFERENT TIMING THROUGH THE FCST PERIOD. THEREFORE...I WILL ONLY TRY TO TIME THE PCPN EARLY IN THE PERIOD AND EMPHASIZE THE DIURNAL NATURE OF THE PCPN. POPS WILL GENERALLY REFLECT GUIDANCE. TO ALL SURROUNDING OFFICES...THANKS FOR YOUR COOR. LONG RANGE...THE PATTERN CONTINUES. HOWEVER...BY TUE...THE UPPER TROUGH LOOKS TO WEAKEN AND FLATTEN OUT ENOUGH TO LEAVE PCPN OUT FOR NOW...ALTHOUGH ISOLATED CNVCTN REMAINS PSBL. FCSTID = 9 MPO 66 77 64 80 / 80 50 40 40 ABE 68 83 65 85 / 70 60 50 40 RDG 68 83 65 85 / 70 50 50 40 PHL 70 85 72 87 / 50 50 50 40 12N 69 81 66 84 / 80 60 60 50 SMQ 68 84 67 86 / 70 60 70 40 TTN 69 86 70 86 / 60 60 60 40 MIV 69 85 70 87 / 40 50 50 40 ACY 72 82 72 85 / 40 60 60 40 ILG 70 85 72 87 / 40 50 50 40 DOV 70 85 71 87 / 40 40 40 40 GED 71 86 71 87 / 50 40 40 40 ESN 71 84 72 87 / 40 30 30 40 .PHI... DE...NONE. MD...NONE. NJ...FLOOD WATCH FOR THIS EVENING FOR ZONES NJZ001...NJZ007>008. PA...FLOOD WATCH FOR THIS EVENING FOR ZONES PAZ054>055...PAZ061>062. MARINE...NONE (SCA DISCONTINUED). RNS
Hazardous weather outlook, Aug 5, 5:24 AM EST, 8 hours 36 minutes before
DEZ001>004-MDZ008-012-015-019-020-NJZ001-007>010-012>027-PAZ054-055- 060>062-067>071-051115- HAZARDOUS WEATHER OUTLOOK...CORRECTED NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 420 AM EDT TUE AUG 5 2003 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL AND SOUTHEAST PENNSYLVANIA...DELAWARE...THE NORTHERN MARYLAND EASTERN SHORE...AND NEW JERSEY EXCLUDING THE FIVE NORTHEAST COUNTIES. .DAY ONE...TODAY A FLOOD WATCH HAS BEEN ISSUED FOR THE LEHIGH VALLEY...THE POCONO MOUNTAINS AND NORTHWEST NEW JERSEY. THERE IS ALSO A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE ENTIRE AREA. BIGGEST THREATS ARE EXCESSIVE RAINFALL AND LARGE HAIL ALTHOUGH GUSTY WINDS BELOW 45 MPH CAN BRING DOWN SOME TREES WITH THE WET GROUND. THERE IS A MODERATE RISK OF RIP CURRENTS ALONG THE COAST. .DAYS TWO THROUGH SEVEN... THE THREAT FOR SHOWERS AND THUNDERSTORMS WITH HEAVY RAINS EXISTS EACH DAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE REQUIRED. WN
In the hours before
Special weather statement, Aug 5, 10:20 AM EST, 3 hours 40 minutes before
DEZ002>004-MDZ012-015-019-020-051700- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1120 AM EDT TUE AUG 5 2003 ...THUNDERSTORMS MOVING ACROSS THE DELMARVA... AN AREA OF THUNDERSTORMS...SOME WITH WIND GUSTS TO 35 MPH...WILL MOVE ACROSS PORTIONS OF DELAWARE AND THE NORTHERN MARYLAND EASTERN SHORE FROM SOUTHWEST TO NORTHEAST LATE THIS MORNING AND EARLY THIS AFTERNOON. THE STRONGEST STORMS HAVE FREQUENT CLOUD TO GROUND LIGHTNING AND VERY HEAVY DOWNPOURS IN ADDITION TO GUSTY WINDS. ANY LIGHTNING IS POTENTIALLY DEADLY...AND THE DOWNPOURS COULD CAUSE SOME PONDING OF WATER ON ROADWAYS AND POOR DRAINAGE AREAS. MPD
Special weather statement, Aug 5, 11:25 AM EST, 2 hours 35 minutes before
DEZ001>004-MDZ008-012-015-019-020-051800- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1225 PM EDT TUE AUG 5 2003 ...THUNDERSTORMS MOVING ACROSS THE DELMARVA... AN AREA OF THUNDERSTORMS...SOME WITH WIND GUSTS OF 25 TO 35 MPH... WILL MOVE ACROSS PORTIONS OF DELAWARE AND THE NORTHERN MARYLAND EASTERN SHORE FROM SOUTHWEST TO NORTHEAST EARLY THIS AFTERNOON. THE STRONGEST STORMS HAVE FREQUENT CLOUD TO GROUND LIGHTNING AND VERY HEAVY DOWNPOURS IN ADDITION TO GUSTY WINDS. ANY LIGHTNING IS POTENTIALLY DEADLY...AND THE DOWNPOURS COULD CAUSE SOME PONDING OF WATER ON ROADWAYS AND POOR DRAINAGE AREAS. MPD
Special weather statement, Aug 5, 12:44 PM EST, 1 hour 16 minutes before
DEZ001-MDZ008-PAZ060-067-051915- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 144 PM EDT TUE AUG 5 2003 ...STRONG THUNDERSTORM NORTHEAST MARYLAND... AT 140 PM RADAR WAS TRACKING AN INTENSIFYING THUNDERSTORM OVER HARFORD COUNTY IN NORTHEAST MARYLAND. THIS STORM HAS SHOW AN INCREASE IN INTENSITY OVER THE PAST 15 MINUTES AND WAS MOVING TO THE NORTH AT 25 TO 30 MPH. ON ITS PRESENT MOVEMENT...THE THUNDERSTORM WILL SKIRT THE WESTERN BORDER OF CECIL COUNTY MARYLAND AND THE EXTREME SOUTHWEST PART OF CHESTER COUNTY. TORRENTIAL RAIN...FREQUENT LIGHTNING AND POSSIBLE WIND GUSTS OF 35 TO 40 MPH ARE POSSIBLE. EBERWINE
The radar
The Philadelphia radar (KDIX), 71 km away, was scanning. The volume nearest the first event began at 19:01 UTC.
Event by event
1 flash flood. Local standard time, as filed.
What these are
- Flash Flood
- Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Lightning Strike in Colorado, August 5, 2003
- Flash Flooding in New York, August 5, 2003
- Hail and Damaging Winds in Kansas, August 5, 2003
- Hail and Damaging Winds in Virginia, August 5, 2003
- Flash Flood in New Jersey, August 5, 2003
- Flash Flooding and Lightning Strike in New York, August 5, 2003
- Flash Flood and Flood in Ohio, August 5, 2003
- Lightning Strike in Oregon, August 5, 2003
- Hail and Damaging Winds in Oklahoma, August 5, 2003
- Flood and Damaging Wind in Pennsylvania, August 5, 2003
- Tornado and Flash Flooding in New York, August 5, 2003
- Flash Flood in New York, August 5, 2003
More
Every storm in New Jersey in 2003Every state in 2003This day in weather historyWarnings in New Jersey, August 2003
Sources
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5333131.