Alert archive / Pennsylvania / River Flood Warnings in 2018

River Flood Warning 46, NWS Philadelphia/Mount Holly

September 28, 2018Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this river flood warning at Sep 28, 2018, 5:33 AM EDT for Montgomery County, Pennsylvania. It took effect at Sep 28, 2018, 9:00 AM EDT. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Sep 28, 2018, 5:33 AM EDT (09:33 UTC)
In effect from: Sep 28, 2018, 9:00 AM EDT
Expired: Sep 28, 2018, 11:05 AM EDT
In force: 2 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 09:36 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 10.69 ft at Sep 28, 2018, 8:00 AM EDT.

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.

025 
WGUS41 KPHI 280933
FLWPHI
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mt Holly NJ
533 AM EDT Fri Sep 28 2018

...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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SAFETY MESSAGE...Do not attempt to drive through flooded areas. The water may be
deeper than you think.

&&

PAC091-281532-
/O.NEW.KPHI.FL.W.0046.180928T1300Z-180929T0100Z/
/GRAP1.1.ER.180928T1300Z.180928T1400Z.180928T1900Z.NO/
533 AM EDT Fri Sep 28 2018

The National Weather Service in Mount Holly NJ has issued a 

* Flood Warning for 
  The Perkiomen Creek at Graterford.
* from this morning to this evening...Or until the warning is cancelled.
* At  5:16 AM Friday the stage was 8.9 feet.
* Flood stage is 11.0 feet.
* Minor flooding is forecast.
* Forecast...Rise above flood stage by late this morning and continue to rise to
  near 12.2 feet by late this morning.the river will fall below flood stage by 
  late this afternoon.
* Impact...At 12.0 feet...Penitentiary Bridge is closed. Flooding begins in 
  Collegeville. Houses on the right bank in Graterford take on water.
* Flood history...This crest compares to a previous crest of 12.1 feet on Oct 28 
  2003.  

 
&&

                         FLD    OBSERVED           FORECAST
 LOCATION                STG    STG  DAY TIME      CREST

Perkiomen Creek
  Graterford             11.0    8.89  Fri 5 AM    12.2    Fri 10 AM
 
&&
 
LAT...LON 4024 7549 4024 7542 4011 7542 4012 7547
                                      

$$

1 follow-up statement

374 
WGUS81 KPHI 281505
FLSPHI
Flood Statement
National Weather Service Mt Holly NJ
1105 AM EDT Fri Sep 28 2018

...The Flood Warning is cancelled for the following rivers in
Pennsylvania...

  Perkiomen Creek At Graterford affecting Montgomery County

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SAFETY MESSAGE...Do not attempt to drive through flooded areas.
The water may be deeper than you think.

&&

PAC091-281535-
/O.CAN.KPHI.FL.W.0046.000000T0000Z-180929T0100Z/
/GRAP1.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.NO/
1105 AM EDT Fri Sep 28 2018

The Flood Warning is cancelled for
  The Perkiomen Creek at Graterford.
* At 10:46 AM Friday the stage was 10.3 feet.
* Flood stage is 11.0 feet.
* Forecast...The river crested below flood stage at 10.7 feet. 

&&

                         FLD    OBSERVED           FORECAST
 LOCATION                STG    STG    DAY TIME    CREST

Perkiomen Creek
  Graterford             11.0   10.32  Fri 11 AM   Slowly falling
 
&&
 
LAT...LON 4024 7549 4024 7542 4011 7542 4012 7547
                                      

$$

Kruzdlo

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 28, 12:10 AM EDT	Areal Flood Advisory	PHI	Berks, Carbon, Lehigh, Monroe, Northampton	13 hr
Sep 28, 1:44 AM EDT	Areal Flood Advisory	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	5 hr
Sep 28, 3:13 AM EDT	Areal Flood Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	4 hr
Sep 28, 4:59 AM EDT	River Flood Warning	PHI	Chester	7 hr
Sep 28, 7:33 AM EDT	Areal Flood Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	5 hr
Sep 28, 8:28 AM EDT	River Flood Warning	PHI	Chester, Delaware	13 hr
Sep 28, 8:33 AM EDT	River Flood Warning	PHI	Chester, Montgomery, Philadelphia	7 hr
Sep 28, 12:31 PM EDT	Areal Flood Warning	PHI	Montgomery, Philadelphia	2 hr

Nearby

River Flood Warnings in Pennsylvania, 2018 Every river flood warning in 2018

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.