Flash Flood, Chester
- When
- August 12, 6:00 PM EST to 9:45 PM EST
- Where
- Chester County, Honey Brook
- Reported by
- NEWSPAPER
- Coordinates
- 39.973, -75.748 (the zone’s center; the record gives no point)
Flash Flood in Pennsylvania, August 12, 2001
Slow moving thunderstorms with torrential downpours caused flooding of streams and poor drainage flooding across the northern tier of Chester County from Honey Brook east through Phoenixville. Flash flooding of smaller streams were reported around Honey Brook and the French Creek.
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.
Slow moving thunderstorms with torrential downpours caused flooding of streams and poor drainage flooding across the northern tier of Chester County from Honey Brook east through Phoenixville. Flash flooding of smaller streams were reported around Honey Brook and the French Creek. Doppler Radar storm total estimates ranged from 2.5 to 4.0 inches across the northern tier of the county. Actual amounts included 3.80 inches in Honey Brook and 2.95 inches in Glenmoore. No serious injuries were reported. The French creek in Phoenixville exceeded its 8 foot flood stage from 805 p.m. EDT through 1036 p.m. EDT on the 12th. It crested at 8.77 feet at 845 p.m. EDT.
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 12, 1:30 PM EST, 4 hours 30 minutes earlier.
Area forecast discussion, Aug 12, 1:30 PM EST, 4 hours 30 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 230 PM EDT SUN AUG 12 2001 FFA WILL BE CONTD THRU TNGT AS CONVECTIVE ACTVTY HAS INCRD DURG THE LAST FEW HRS. WE HAVE CAUGHT A BREAK WITH THE CLDY SKIES...IT HAS COOLED THE CONVECTIVE JUICES A BIT. EVEN WITH THE CLDY SKIES...WE CAME CLOSE TO THE LOWERED FFG VALUES IN THE MD ERN SHORE. TWO SHRT WVS OF CONCERN...THE ONE MOVG ACRS DELMARVA ATTM AND THE SECOND HANDLED BY THE ETA BETTER OVR WV/ERN OH/SWRN PA. BLV GREATEST THREAT FOR FLOODING SHLD BE WITH THIS FEAT...ESP IF CONVECTION ARRIVES ERLY THIS EVE AND SHLD END ONCE THIS SHRT WV MOVES EWD OVRNGT. GIVEN FCST MOVEMENT AND INABILITY OF CONVECTION TO GET TOO FAR N OF THE MASON-DIXON LINE...WILL NOT BE EXTENDING THE FFA ANY FTHR N. IF THEY DIDN/T GET DRENCHED YDA WOULD HAVE PBLY PULLED THE WATCH DOWN IN THE LEHIGH VLY WITH THIS PKG. CORFIDI VECTORS FCSTG NO MOVEMENT THRU TNGT IN SERN PART OF OUR CWA LOSS OF DAYTIME HEATG SHLD SIMMER CONDS DOWN. WE HAVE A THETA E MAX OVR THE CWA ATTM...BUT THIS DOES GET REPLACED BY TROFFINESS TWD MRNG. OTRWISE THERE/S ENUF INSTAB AND CAPE TO SUPPORT THUNDER INTO THE NGT. BOTH THE ETA AND AVN DVLP A SHRT WV TWD MRNG WHICH MIGHT DVLP PCPN AGN. IT DID NOT OCR WITH MUCH ZEST THIS MRNG...ALTHO ATTM THIS POINT IS MOOT GIVEN CUR FFA AND WORDG OF ZONES. HARD TO ARGUE WITH GUID MINS FOR TNGT. FOG SHLD FORM AGN IN MUGGY AIR. ON MON ETA AND AVN CONT TO AGREE TO DISAGREE. ETA BRINGS CDFNT CLS TO WRN EDGE OF OUR CWA BY MON MRNG THEN WAITS FOR 2NDRY FRONTOGEN TO FINALLY MOVE HUMID AIR MASS OFSHR AT NGT. AVN APRS ABOUT 6 HRS SLOR AND INCRS THE CHCS FOR MORE FLDG TSRAS ON MON. ATTM WE DO NOT PLAN ON EXTDG FFA. IF THE ETA VERIFIES IT WON/T BE NECESSARY AS THERE IS STG NEG THETA E ADVT DURG THE DAY AND PWATS ARE IN A FREE FALL DURG MAX TIME OF DAYTIME HEATG. EVEN THE AVN HAS THE THETA E RDG IN FAR ERN ZONES BY AFTN AND STARTS DROPPING THE PWATS TWD EVE. MID SHIFT COULD REACCESS ALSO BASED UPON HOW MUCH HVY PCPN DOES OR DOES NOT FALL TNGT. OTRWISE PRFR TO LEAN TWD SLGTLY HIER POPS ON THE MAV AND CORRESPONDINGLY LWR MAX TEMPS. FULL SUN MACROS ARE IN THE MID 80S WHICH MIGHT BE STRETCHING IT GIVEN CONVECTIVE TEMPS ARE IN THE LWR 80S. WILL END PCPN CHCS WITH THE DAY IN OUR NWRN CWA...BUT WILL CARRY A LINGERING POP ACRS SERN 2/3RDS OF CWA FOR THE EVE ONLY. THERE SHLD BE SOME FOG FRMG OVRNGT AS SKIES CLR. GUID MINS AGN LOOK RSNBL FOR MON NGT. THE THREE WORDS EVERYONE WANTS TO HEAR HERE (OTHER THAN I LOVE YOU) WILL BE IN THE ZONES FOR TUE (AND LESS HUMID). ENUF DRY AIR FILTERS INTO MOST OF OUR ZONES PLUS THE ETA/S USUAL CAP TO KEEP THE CWA DRY. IT MIGHT BE CLS IN OUR FAR SRN ZONES ESP IF THE SLOR AVN VERIFIES. ATTM ITS MOS BARELY CARRIES A CHC POP FOR SBY...SO WE/LL LEAVE THE CWA DRY. ETA FULL SUN MAXT MACROS SAY MID 80S TO AROUND 90 FOR TUE. SO WILL DO A FLIP FLOP WITH THE GUID AND GO WITH THE WRMR AVN MOS FOR TUE. MAR: ALL/S QUIET AGAIN ALTHO SEAS WILL BE NEARING SCA CRIT. MY APOLOGIES FOR YDA/S SUSSEX CTY ANNIVERSARY DAY WHL IT WAS ON A SAT LAST YR...TDY IS THE TRUE CALENDAR YR ANNIVERSARY ONE WE ALL HOPE WON/T HAVE NEW FAMILY MEMBERS IN THE YEARS TO COME. .PHI... DE...FLASH FLOOD WATCH UNTIL 500 AM EDT MONDAY FOR ZONES DEZ001>004. MD...FLASH FLOOD WATCH UNTIL 500 AM EDT MONDAY FOR ZONES MDZ008... MDZ012...MDZ015...MDZ019>020. NJ...FLASH FLOOD WATCH UNTIL 500 AM EDT MONDAY FOR ZONES NJZ009>010...NJZ012>026. PA...FLASH FLOOD WATCH UNTIL 500 AM EDT MONDAY FOR ZONES PAZ060>062...PAZ067>071. MARINE...NONE TFG
The radar
The Philadelphia radar (KDIX), 114 km away, was scanning. The volume nearest the first event began at 22:57 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
- Heat in Missouri, August 12, 2001
- Lightning Strike in Alabama, August 12, 2001
- Heat in Texas, August 12, 2001
- Wildfire in Oregon, August 12 to 27, 2001
- Flash Flooding in Mississippi, August 12, 2001
- Wildfire in Washington, August 12 to 31, 2001
- Hail in Nebraska, August 12, 2001
- Flash Flood in Tennessee, August 12 to 13, 2001
- Flash Flood in Tennessee, August 12, 2001
- Lightning Strike in New Jersey, August 12, 2001
- Damaging Wind in Arizona, August 12, 2001
- Flash Flooding in West Virginia, August 12, 2001
More
Every storm in Pennsylvania in 2001Every state in 2001This day in weather historyWarnings in Pennsylvania, August 2001
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: 5268776.