Flood, Montgomery
- When
- October 27, 12:00 PM EST to October 28, 12:41 AM EST
- Where
- Montgomery forecast zone
- Reported by
- AWOS,ASOS,MESONET,ETC
Showers and thunderstorms associated with a slow moving cold front produced poor drainage flooding and stream flooding in Montgomery County. Heavy rain started during the morning and persisted into the early evening.
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.
The episode as NWS PHI wrote it up.
Showers and thunderstorms associated with a slow moving cold front produced poor drainage flooding and stream flooding in Montgomery County. Heavy rain started during the morning and persisted into the early evening. Doppler Radar storm total estimates ranged between 2 and 4 inches with the highest amounts in the upper part of the county. The East Branch of the Perkiomen Creek at Schwenksville was above its 7 foot flood stage from Noon EST on the 27th through 1241 a.m. EST on the 28th. It crested at 8.97 feet at 530 p.m. EST. Farther downstream, the main stem of the Perkiomen Creek at Graterford was above its 11 foot flood stage from 405 p.m. through 1142 p.m. EST on the 27th. It crested at 12.08 feet at 8 p.m. EST on the 27th. Storm totals included 3.79 inches in Royersford, 3.60 inches in Palm, 3.50 inches in Pottstown, 3.32 inches in Blue Bell, 3.10 inches in Green Lane, 3.05 inches in Willow Grove and 2.67 inches in Wynnewood.
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 Oct 27, 8:47 AM EST, 3 hours 13 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
847 AM EST MON OCT 27 2003
QUICK UPDATE TO EXPAND FLOOD WATCH AREA TO THE NW...AND TO INCLUDE
PHILLY CTY. ALSO ADJUSTED SVR STATEMENT TO REFLECT LATEST SPC OTLK.
KRAUS
-----------------------------
PREVIOUSLY...
PRODUCTS...INCLUDING SEVERE WEATHER OUTLOOK AND FLOOD WATCH...HAVE
ALREADY BEEN ISSUED. DYNAMICS...POTENTIAL FOR THERMODYNAMICS...AND
WIND FIELDS HAVE ALREADY BEEN DISCUSSED IN PREVIOUS AFDS. THERE IS
STILL SUPPORT FROM THE UPPER JET...DIFLUENCE AT MID LEVELS...STRONG
OMEGA PROGGED...A MID LEVEL TROF THAT IS TILTING NEGATIVE ALBEIT AS
IT WEAKENS...A STRONG H8 JET...GOOD SPEED AND DIRECTIONAL SHEAR FROM
THE SFC TO H7...NO CONVECTIVE INHIBITION AND A CHANCE FOR MORE
INSTABILITY THAN IS PROGGED ON THE SFC SRLY FLOW. THE OCEAN IS NOW A
VERY DECENT SOURCE OF LOW LEVEL THETA E. MODELS DO NOT DIFFER TOO
MUCH AND HAVE NOT CHANGED SIGNIFICANTLY SINCE YESTERDAY. SPC KEEPS
MOST OF FA IN SLIGHT RISK...AND THEY MENTION THE POSSIBILITY OF A
FEW SUPERCELLS AND EVEN AN ISOLATED TORNADO. AS NOTED
ABOVE...STATEMENT IS OUT AND ZONES ARE WORDED ACCORDINGLY.
FFG AND FFH VALUES...GIVEN HIGH END OF EXPECTED RAINFALL
AMOUNTS...INDICATE SOME FLOODING OF THE AREAS AND STREAMS MOST PRONE
TO IT IS POSSIBLE...HENCE THE FLOOD WATCH FOR NORTHERN
DELAWARE...THE NORTHERN AND WESTERN SUBURBS OF PHILADELPHIA AND
MERCER COUNTY NJ.
AFTER TODAY...THE GFS IS THE MOST ACTIVE WITH THE BAROCLINIC ZONE
OFF THE COAST...AND EVEN IT DOESNT BRING PCPN INTO FA TUE NIGHT INTO
WED. THEREFORE DIDNT CHANGE THE FORECAST MUCH AFTER TONIGHT...EXCEPT
TO MAKE TUE A BIT MORE OPTIMISTIC.
SCA UP FOR THE BAY AND COAST.
FCSTID = 45
MPO 60 36 50 39 / 100 30 10 40
ABE 65 41 57 42 / 100 30 10 40
RDG 65 42 57 42 / 100 30 10 40
PHL 69 46 59 48 / 100 40 0 30
12N 64 38 56 41 / 100 30 10 40
SMQ 66 40 59 44 / 100 40 0 40
TTN 67 44 59 46 / 100 40 0 40
MIV 69 42 60 45 / 100 60 0 10
ACY 68 46 60 52 / 100 60 0 10
ILG 69 44 59 46 / 100 40 0 30
DOV 72 45 62 48 / 100 60 0 10
GED 72 45 62 47 / 100 60 0 10
ESN 72 45 61 47 / 100 60 0 10
.PHI...FLOOD WATCH TDA DE1, ALL PA ZONES, NJ1,7,15
SML CRAFT ADVY CST AND DE BAY.
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</html>1 flood. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2003Every state in 2003This day in weather historyWarnings in Pennsylvania, October 2003
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 2026-10-01. Each event’s entry at NCEI: 5371890.