Flood, Lehigh
- When
- September 23, 6:00 AM EST to 4:25 PM EST
- Where
- Lehigh forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 40.613, -75.592 (the zone’s center; the record gives no point)
Flooding in Pennsylvania, September 23, 2003
A slow moving cold front helped produce heavy rain as it displaced a warm and humid air mass preceding it across the Lehigh Valley. Widespread flooding was reported across the region and made for a difficult morning commute.
Where it happened
Every event with a place to put it; 2 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
- 2
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.
A slow moving cold front helped produce heavy rain as it displaced a warm and humid air mass preceding it across the Lehigh Valley. Widespread flooding was reported across the region and made for a difficult morning commute. Doppler Radar storm total estimates ranged from 1 to 4 inches with th highest in northwest Lehigh County. The heaviest rain fell between 5 a.m. and 9 a.m. EDT. Runoff from the heavy rain led to flooding along sections of the Lehigh River including Walnutport. In Walnutport, the Lehigh River was above its 8 foot flood stage from 1225 p.m. through 525 p.m. EDT on the 23rd. It crested at 8.39 feet at 245 p.m. EDT. The Jordan Creek in Allentown flooded Jordan Park and also the Home Depot parking lot in Whitehall Township (Lehigh County). Sections of both Pennsylvania State Routes 309 and 248 were closed in Lehigh County. In Northampton County, the Lehigh River flooded Lehigh Drive in West Easton for about three-quarters of a mile. Pennsylvania State Route 145 in Lehigh Township was closed across the Lehigh River. Flooding along the Bushkill Creek forced the closure of Zucksville Road. The heavy rain weakened some trees and consequently knocked down some power lines in the Lehigh Valley. About 6,000 homes and businesses lost power. Storm totals included 1.95 inches at the Lehigh Valley International Airport and 1.84 inches in Easton. September 2003 was an unseasonably wet month throughout Eastern Pennsylvania. On a county weighted average, monthly precipitation totals ranged from 5.9 inches in Philadelphia County to 12.5 inches in Monroe County. The Lehigh County average was 12.0 inches and Northampton County 10.8 inches. Normal is around 4.1 inches. The September monthly precipitation total at the Lehigh Valley International Airport was 11.08 inches, which was 6.71 inches wetter than normal and the second wettest September on record.
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 Sep 23, 2:52 AM EST, 3 hours 8 minutes earlier.
Area forecast discussion, Sep 23, 2:52 AM EST, 3 hours 8 minutes before
AREA FORECAST DISCUSSION...CORRECTED TO INCLUDE DE CTY PA IN WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
352 AM EDT TUE SEP 23 2003
DROPPING FLD WATCH ESSENTIALLY FROM PHL E...SPECIFIC CNTYS LISTED
BLO...AS THAT AREA DID NOT HAVE SGFNT RAINS LAST WK...AS OPPOSED TO
OUR NWRN ZONES AND AREA TO THE IMMEDIATE W OF PHL.
OTRW...PCPN SHOULD END FM THE W BY NOON OR SHRTLY THRFTR...THEN DRY
INTO THU WHEN NXT FNT ARRIVES FM THE NW. SLOWED PCPN TIMING DOWN
JUST A BIT...BGNG THU MRNG NWRN ZONES AND THU AFTN SERN ZONES.
OTRW...LEFT EXTDDS PRETTY MUCH AS THEY WERE.
NO CHGS ON THE MARINE...SML CRAFT REMAINS UP ALL WTRS.
ZONES AND UPDATED FLOOD WATCH SHOULD FLY BY 430 AM.
.PHI...FLOOD WATCH THIS MRNG PA54-55,60-62,67-70 NJ1,7 DE1 MD8
SML CRAFT ADVY CST AND DE BAY.
KRAUSHazardous weather outlook, Sep 23, 5:28 AM EST, 32 minutes before
DEZ001>004-MDZ008-012-015-019-020-NJZ001-007>010-012>027-PAZ054-055- 060>062-067>071-231230- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 628 AM EDT TUE SEP 23 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 FLOOD WATCHES REMAIN IN EFFECT THIS MORNING FOR MUCH OF THE AREA TO THE NORTH AND WEST OF PHILADELPHIA...AND FLOOD WARNINGS HAVE BEEN ISSUED FOR SOME COUNTIES. THE RAIN WILL MOVE EAST AND SHOULD BE OFF THE COAST BY EARLY AFTERNOON. STORM TOTALS WILL EXCEED THREE INCHES IN SOME SPOTS. THERE IS A MODERATE RISK OF RIP CURRENTS TODAY ALONG THE NEW JERSEY AND DELAWARE COASTS. .DAYS TWO THROUGH SEVEN... NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ASKED TO CALL IN WITH SIGNIFICANT RAINFALL TOTALS...OF TWO INCHES OR MORE. KRAUS
In the hours before
Special weather statement, Sep 23, 4:45 AM EST, 1 hour 15 minutes before
DEZ001>003-MDZ008-012-015-019-020-NJZ001-007>010-012-015>019-021- PAZ054-055-060>062-067>071-231115- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 545 AM EDT TUE SEP 23 2003 ...AREA OF HEAVY RAIN MOVING SLOWLY EAST... AT 530 AM...NATIONAL WEATHER SERVICE RADAR SHOWED AN AREA OF HEAVY RAIN MOVING SLOWLY EAST ACROSS EASTERN PENNSYLVANIA AND MARYLAND. IT EXTENDED FROM THE POCONOS THROUGH ALLENTOWN PA...SOUTH THROUGH CHESTER COUNTY AND THEN ALONG THE NORTHERN CHESAPEAKE BAY. RAINFALL AMOUNTS OF OVER AN INCH IN LESS THAN HALF AN HOUR HAVE BEEN REPORTED. THE RAIN WILL SLOWLY SHIFT EAST INTO THE PHILADELPHIA AND WILMINGTON AREAS AFTER 6 AM...AND ALSO INTO WESTERN NEW JERSEY AND THE NORTHERN DELMARVA. BE ESPECIALLY CAUTIOUS ON THE ROADS THIS MORNING...AS THERE WILL BE WATER PONDED IN LOW LYING AREAS AND UNDERPASSES. SLOW DOWN AND ALLOW FOR EXTRA SPACE BETWEEN YOU AND THE CARS AROUND YOU. A FEW OVERNIGHT RAINFALL REPORTS THROUGH 530 AM...READING AIRPORT IN BERKS COUNTY...2.93 INCHES...AND MOUNT POCONO AIRPORT IN MONROE COUNTY...2.42 INCHES. KRAUS
The radar
The national radar mosaic for the moment the first event began.
Event by event
2 flood. Local standard time, as filed.
Flood, Northampton
- When
- September 23, 6:00 AM EST to 4:25 PM EST
- Where
- Northampton forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 40.754, -75.307 (the zone’s center; the record gives no point)
What these are
- Flood
- Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Tornado in Pennsylvania, September 23, 2003
- Tornado in New Jersey, September 23, 2003
- Tornado in New Jersey, September 23, 2003
- Tornado in New Jersey, September 23, 2003
- Damaging Wind in New Jersey, September 23, 2003
- Damaging Wind in Pennsylvania, September 23, 2003
- Flash Flooding and Flooding in Virginia, September 23 to 24, 2003
- Tornadoes and Damaging Winds in Virginia, September 23, 2003
- Flash Flooding and Damaging Wind in North Carolina, September 23, 2003
- Flash Flooding and Damaging Wind in Massachusetts, September 23, 2003
- Flash Flood and Damaging Wind in New York, September 23, 2003
- High Wind in Alaska, September 23 to 24, 2003
More
Every storm in Pennsylvania in 2003Every state in 2003This day in weather historyWarnings in Pennsylvania, September 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: 5335076, 5335077.