Alert archive / Pennsylvania / River Flood Warnings in 2020
River Flood Warning 41, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this river flood warning at Nov 30, 2020, 5:33 PM EST for Montgomery County, Pennsylvania. It was in force for 10 hr.
The area
The outline as issued.
The facts
- Issued
- Nov 30, 2020, 5:33 PM EST (22:33 UTC)
- Expired
- Dec 1, 2020, 3:36 AM EST
- In force
- 10 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- Minor
County Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 93 km from the middle of the area, began a volume at 22:36 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The river
Written for the forecast point Perkiomen Creek at Graterford (GRAP1). The gauge peaked at 12.46 ft at Nov 30, 2020, 9:00 PM EST.
- Action stage
- 8 ft
- Minor stage
- 11 ft
- Moderate stage
- 13 ft
- Major stage
- 16 ft
This gauge today: stage, forecast and historic crests
Stage from the USGS instantaneous record for site 01473000, one reading an hour, from a day before the product to a day after it ended. Flood stages are today's.
The text
As transmitted.
870 WGUS41 KPHI 302233 FLWPHI BULLETIN - EAS ACTIVATION REQUESTED Flood Warning National Weather Service Mount Holly NJ 533 PM EST Mon Nov 30 2020 ...The National Weather Service in Mount Holly NJ has issued a Flood Warning for the following rivers in Pennsylvania... Perkiomen Creek At Graterford affecting Montgomery County. For the Perkiomen Creek...including Graterford...Minor flooding is forecast. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Flood Warning means that flooding is imminent or occurring. All interested parties should take necessary precautions immediately. Turn around...don't drown when encountering flooded roads. Most flood deaths occur in vehicles. Additional information is available at www.weather.gov/phi. PAC091-011045- /O.NEW.KPHI.FL.W.0041.201130T2233Z-201201T1353Z/ /GRAP1.1.ER.201201T0100Z.201201T0600Z.201201T0752Z.NO/ 533 PM EST Mon Nov 30 2020 The National Weather Service in Mount Holly has issued a * Flood Warning for the Perkiomen Creek At Graterford. * From this afternoon to Tuesday morning. * At 5:15 PM EST Monday the stage was 10.8 feet. * Flood stage is 11.0 feet. * Minor flooding is forecast. * Forecast...The river is expected to rise above flood stage this evening to a crest of 11.5 feet just after midnight tonight. It will then fall below flood stage just after midnight tonight. * Impact at 8.0 feet...Park Avenue in Schwenksville is flooded. The Perkiomen Trail is flooded in Perkiomen Township at Plank Road and Route 113. Ninth Avenue begins to flood in Collegeville. Impact at 11.0 feet...Graterford Road and Penitentiary Bridge are closed due to flooding. Impact at 12.0 feet...Portions of Central Perkiomen Park in Collegeville are flooded. Flood waters expand onto and to the west of First Avenue in Collegeville. * Flood History...This crest compares to a previous crest of 11.5 feet on 12/28/1993. && Stream Fld Observed Fcsts (7 pm) Crest Location Stg Stg Day/Time Tue Wed Stg Time Date Perkiomen Creek Graterford 11.0 10.8 Mon 5 pm 5.3 2.9 11.5 1am 12/01 && LAT...LON 4024 7549 4024 7542 4011 7542 4012 7547 $$ BAH
3 follow-up statements
620 WGUS41 KPHI 010105 FLWPHI BULLETIN - EAS ACTIVATION REQUESTED Flood Warning National Weather Service Mount Holly NJ 805 PM EST Mon Nov 30 2020 ...The Flood Warning continues for the following rivers in Pennsylvania... Perkiomen Creek At Graterford affecting Montgomery County. For the Perkiomen Creek...including Graterford...Minor flooding is forecast. PRECAUTIONARY/PREPAREDNESS ACTIONS... Turn around...don't drown when encountering flooded roads. Most flood deaths occur in vehicles. A Flood Warning means that flooding is imminent or occurring. All interested parties should take necessary precautions immediately. Additional information is available at www.weather.gov/phi. PAC091-011315- /O.CON.KPHI.FL.W.0041.000000T0000Z-201201T1353Z/ /GRAP1.1.ER.201130T2227Z.201201T0300Z.201201T0800Z.NO/ 805 PM EST Mon Nov 30 2020 ...The Flood Warning remains in effect... The Flood Warning continues for the Perkiomen Creek At Graterford. * Until Tuesday morning. * At 7:17 PM EST Monday the stage was 12.1 feet. * Flood stage is 11.0 feet. * Minor flooding is occurring and minor flooding is forecast. * Recent Activity...The maximum river stage in the 24 hours ending at 7:17 PM EST Monday was 12.1 feet. * Forecast...The river is expected to rise to a crest of 12.2 feet late this evening. It will then fall below flood stage late tonight. * Impact at 8.0 feet...Park Avenue in Schwenksville is flooded. The Perkiomen Trail is flooded in Perkiomen Township at Plank Road and Route 113. Ninth Avenue begins to flood in Collegeville. Impact at 11.0 feet...Graterford Road and Penitentiary Bridge are closed due to flooding. Impact at 12.0 feet...Portions of Central Perkiomen Park in Collegeville are flooded. Flood waters expand onto and to the west of First Avenue in Collegeville. Impact at 13.0 feet... First Avenue in Collegeville becomes impassable. * Flood History...This crest compares to a previous crest of 12.1 feet on 10/28/2003. && Stream Fld Observed Fcsts (7 pm) Crest Location Stg Stg Day/Time Tue Wed Stg Time Date Perkiomen Creek Graterford 11.0 12.1 Mon 7 pm 5.4 2.9 12.2 10pm 11/30 && LAT...LON 4024 7549 4024 7542 4011 7542 4012 7547 $$ BAH
755 WGUS81 KPHI 010205 FLSPHI Flood Statement National Weather Service Mount Holly NJ 905 PM EST Mon Nov 30 2020 ...The Flood Warning is extended for the Perkiomen Creek at Graterford... For the Perkiomen Creek...minor flooding is occurring and forecast to continue. PRECAUTIONARY/PREPAREDNESS ACTIONS... Motorists should not attempt to drive around barricades or drive through flooded areas. Additional information is available at www.weather.gov/phi. PAC091-011400- /O.EXT.KPHI.FL.W.0041.000000T0000Z-201201T1400Z/ /GRAP1.1.ER.201130T2227Z.201201T0400Z.201201T0800Z.NO/ 905 PM EST Mon Nov 30 2020 ...The Flood Warning is now in effect until late tomorrow morning... The Flood Warning continues for the Perkiomen Creek At Graterford. * Until Tuesday morning. * At 8:45 PM Monday the creek level was 12.4 feet. * Flood stage is 11.0 feet. * Minor flooding is occurring and minor flooding is forecast to continue. * Forecast...The creek is expected to rise to a crest of 12.6 feet late this evening. It will then fall below flood stage late tonight. * Impact at 12.0 feet...portions of Central Perkiomen Park in Collegeville are flooded. Flood waters expand onto and to the west of First Avenue in Collegeville. * Flood History...This crest compares to a previous crest of 12.5 feet on 09/22/1979. && Stream Fld Observed Fcsts (7 pm) Crest Location Stg Stg Day/Time Tue Wed Stg Time Date Perkiomen Creek Graterford 11.0 12.4 Mon 8 pm 5.5 3.0 12.6 11pm 11/30 && LAT...LON 4024 7549 4024 7542 4011 7542 4012 7547 $$ Iovino
384 WGUS81 KPHI 010836 FLSPHI Flood Statement National Weather Service Mount Holly NJ 336 AM EST Tue Dec 1 2020 ...The Flood Warning is cancelled for the following rivers in Pennsylvania... Perkiomen Creek at Graterford affecting Montgomery County. PAC091-010945- /O.CAN.KPHI.FL.W.0041.000000T0000Z-201201T0836Z/ /GRAP1.1.ER.700119T1419Z.700119T1419Z.700119T1420Z.NO/ 336 AM EST Tue Dec 1 2020 ...The Flood Warning for the Perkiomen Creek At Graterford has been cancelled... The Flood Warning is cancelled for the Perkiomen Creek At Graterford. * At 3:16 AM EST Tuesday the stage was 9.0 feet. * Flood stage is 11.0 feet. * Forecast...The river is expected to fall to 2.4 feet early Friday morning. && Stream Fld Observed Fcsts (1 am) Crest Location Stg Stg Day/Time Wed Thu Stg Time Date Perkiomen Creek Graterford 11.0 9.0 Tue 3 am 4.1 2.8 7.1 7am 12/01 && LAT...LON 4024 7549 4024 7542 4011 7542 4012 7547 $$ CMS
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 30, 12:15 PM EST | Areal Flood Advisory | PHI | Chester, Delaware | 3 hr |
| Nov 30, 12:41 PM EST | Special Weather Statement | PHI | Chester, Montgomery | 49 min |
| Nov 30, 2:17 PM EST | Areal Flood Warning | PHI | Berks, Bucks, Lehigh, Montgomery | 9 hr |
| Nov 30, 2:18 PM EST | Coastal Flood Advisory | PHI | Bucks, Delaware, Philadelphia | 2 hr |
| Nov 30, 2:41 PM EST | Severe Thunderstorm Warning | PHI | Chester, Delaware | 49 min |
| Nov 30, 2:48 PM EST | Areal Flood Warning | PHI | Chester, Delaware, Montgomery | 8 hr |
| Nov 30, 3:01 PM EST | Severe Thunderstorm Warning | PHI | Chester, Delaware, Montgomery, Philadelphia | 44 min |
| Nov 30, 3:26 PM EST | Areal Flood Warning | PHI | Berks, Bucks, Carbon, Lehigh, Monroe, Northampton | 4 hr |
| Nov 30, 3:43 PM EST | Severe Thunderstorm Warning | PHI | Berks, Bucks, Lehigh, Monroe, Montgomery, Northampton and 1 more | 47 min |
| Nov 30, 3:51 PM EST | River Flood Warning | PHI | Chester | 14 hr |
| Nov 30, 3:53 PM EST | Areal Flood Warning | PHI | Monroe, Northampton | 16 hr |
| Nov 30, 3:53 PM EST | Tornado Warning | PHI | Bucks, Montgomery | 13 min |
| Nov 30, 4:17 PM EST | Areal Flood Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 10 hr |
| Nov 30, 5:30 PM EST | River Flood Warning | PHI | Chester, Delaware | 16 hr |
| Nov 30, 5:35 PM EST | River Flood Warning | PHI | Delaware | 4 hr |
Nearby
River Flood Warnings in Pennsylvania, 2020Every river flood warning in 2020
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive; the gauge from the NWS water service and the USGS.