Alert archive / Pennsylvania / River Flood Warnings in 2019

River Flood Warning 21, NWS Philadelphia/Mount Holly

July 11, 2019Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this river flood warning at Jul 11, 2019, 6:57 PM EDT for Montgomery County, Pennsylvania. It took effect at Jul 11, 2019, 8:31 PM EDT. It was in force for 11 hr.

The area

The outline as issued.

The facts

Issued: Jul 11, 2019, 6:57 PM EDT (22:57 UTC)
In effect from: Jul 11, 2019, 8:31 PM EDT
Expired: Jul 12, 2019, 7:02 AM EDT
In force: 11 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 22:57 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 15.95 ft at Jul 11, 2019, 11:00 PM 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.

733 
WGUS41 KPHI 112257
FLWPHI
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mt Holly NJ
657 PM EDT Thu Jul 11 2019

...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.

&&

PAC091-120457-
/O.NEW.KPHI.FL.W.0021.190712T0400Z-190712T1317Z/
/GRAP1.1.ER.190712T0400Z.190712T0600Z.190712T0717Z.NO/
657 PM EDT Thu Jul 11 2019

The National Weather Service in Mount Holly NJ has issued a 

* Flood Warning for 
  The Perkiomen Creek at Graterford.
* From late tonight to Friday morning...or until the warning is 
  cancelled.
* At 6:31 PM Thursday the stage was 6.2 feet.
* Flood stage is 11.0 feet.
* Minor flooding is forecast.
* Forecast...Rise above flood stage to near 11.3 feet tonight.
  The river will fall below flood stage by early tomorrow.
* Impact...At 11.0 feet...Graterford Road and Penitentiary Bridge 
  are closed due to flooding.
* Flood history...This crest compares to a previous crest of 11.4 
  feet on Aug 13 2018.  
 
&&

                         FLD    OBSERVED           FORECAST
 LOCATION                STG    STG    DAY TIME    CREST

Perkiomen Creek
  Graterford             11.0    6.19  Thu 7 PM    11.3    Fri 2 AM 
 
&&
 
LAT...LON 4024 7549 4024 7542 4011 7542 4012 7547
                                      

$$

Kruzdlo

3 follow-up statements

919 
WGUS41 KPHI 120033
FLWPHI
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mt Holly NJ
833 PM EDT Thu Jul 11 2019

...Forecast flooding changed from Minor to Moderate severity
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.

&&

PAC091-120632-
/O.EXT.KPHI.FL.W.0021.190712T0031Z-190712T1500Z/
/GRAP1.2.ER.190711T2344Z.190712T0300Z.190712T0900Z.NO/
833 PM EDT Thu Jul 11 2019

...Forecast flooding increased from Minor to Moderate severity...

The Flood Warning continues for 
 The Perkiomen Creek At Graterford.
* Until Friday morning...or until the warning is cancelled.
* At 8:15 PM Thursday the stage was 12.1 feet.
* Flood stage is 11.0 feet.
* Minor flooding is occurring and Moderate flooding is forecast.
* Forecast...The river will continue rising to near 13.5 feet by 
  tonight. The river will fall below flood stage early tomorrow.
* Impact...At 14.0 feet...Storm sewers back up in Collegeville 
  and flood Route 29.
* Flood history...This crest compares to a previous crest of 13.3
  feet on Nov 3 2018.  
 
&&

                         FLD    OBSERVED           FORECAST
 LOCATION                STG    STG    DAY TIME    CREST

Perkiomen Creek
  Graterford             11.0   12.10  Thu 8 PM    13.5    Thu 11 PM
 
&&
 
LAT...LON 4024 7549 4024 7542 4011 7542 4012 7547
                                      

$$

Kruzdlo

997 
WGUS81 KPHI 120227
FLSPHI
Flood Statement
National Weather Service Mt Holly NJ
1027 PM EDT Thu Jul 11 2019

...The Flood Warning continues 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.

&&

PAC091-121226-
/O.EXT.KPHI.FL.W.0021.000000T0000Z-190712T1600Z/
/GRAP1.2.ER.190711T2344Z.190712T0400Z.190712T1000Z.NO/
1027 PM EDT Thu Jul 11 2019

The Flood Warning continues for
  The Perkiomen Creek at Graterford.
* At 10:02 PM Thursday the stage was 15.3 feet.
* Flood stage is 11.0 feet.
* Moderate flooding is occurring.
* Forecast...The river will continue rising to near 15.4 feet around
  midnight. The river will fall below flood stage tomorrow morning.
* Impact...At 15.0 feet...East Main Street in Collegeville floods.
* Flood history...This crest compares to a previous crest of 15.7 
  feet on Oct 19 1996.  
 
&&

                         FLD    OBSERVED           FORECAST
 LOCATION                STG    STG    DAY TIME    CREST

Perkiomen Creek
  Graterford             11.0   15.31  Thu 10 PM   15.4    Fri 12 AM
 
&&
 
LAT...LON 4024 7549 4024 7542 4011 7542 4012 7547
                                      

$$

Kruzdlo

253 
WGUS81 KPHI 121102
FLSPHI
Flood Statement
National Weather Service Mt Holly NJ
702 AM EDT Fri Jul 12 2019

...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.

&&

PAC091-121132-
/O.CAN.KPHI.FL.W.0021.000000T0000Z-190712T1600Z/
/GRAP1.3.ER.190711T2344Z.190712T0317Z.190712T0949Z.NO/
702 AM EDT Fri Jul 12 2019

The Flood Warning is cancelled for
  The Perkiomen Creek at Graterford.
* At  6:46 AM Friday the stage was 8.4 feet.
* Flood stage is 11.0 feet.
* Fell below flood stage at 5:49 AM Friday.
* Forecast...The river will continue to fall through this morning.


&&

                         FLD    OBSERVED           FORECAST
 LOCATION                STG    STG  DAY TIME      CREST

Perkiomen Creek
  Graterford             11.0    8.43  Fri 7 AM     9.2    Fri 8 AM 
 
&&
 
LAT...LON 4024 7549 4024 7542 4011 7542 4012 7547
                                      

$$

Meola

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 11, 3:44 AM EDT	Flash Flood Watch	PHI	Berks, Bucks, Chester, Delaware, Lehigh, Montgomery and 2 more	18 hr
Jul 11, 12:33 PM EDT	Special Weather Statement	PHI	Chester	57 min
Jul 11, 1:23 PM EDT	Special Weather Statement	PHI	Chester, Delaware	52 min
Jul 11, 1:44 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Montgomery, Philadelphia	61 min
Jul 11, 2:41 PM EDT	Special Weather Statement	PHI	Philadelphia	64 min
Jul 11, 2:44 PM EDT	Special Weather Statement	PHI	Bucks, Montgomery	61 min
Jul 11, 2:50 PM EDT	Areal Flood Advisory Emergency	PHI	Berks, Chester, Montgomery	4 hr
Jul 11, 3:00 PM EDT	Flash Flood Warning	PHI	Berks, Chester, Montgomery	8 hr
Jul 11, 3:13 PM EDT	Areal Flood Advisory	PHI	Bucks, Carbon, Lehigh, Monroe, Northampton	4 hr
Jul 11, 3:33 PM EDT	Areal Flood Advisory	PHI	Northampton	4 hr
Jul 11, 3:45 PM EDT	Flash Flood Warning	PHI	Berks, Bucks, Lehigh, Montgomery, Northampton	4 hr
Jul 11, 4:45 PM EDT	Flash Flood Warning Emergency	PHI	Berks, Montgomery	4 hr
Jul 11, 5:12 PM EDT	Flash Flood Warning	PHI	Chester	4 hr
Jul 11, 5:20 PM EDT	Flash Flood Warning	PHI	Bucks, Chester, Montgomery	4 hr
Jul 11, 5:33 PM EDT	Areal Flood Advisory	PHI	Bucks	4 hr
Jul 11, 6:14 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Montgomery, Philadelphia	61 min
Jul 11, 6:15 PM EDT	Flash Flood Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	4 hr
Jul 11, 6:17 PM EDT	Areal Flood Advisory	PHI	Bucks	4 hr
Jul 11, 6:28 PM EDT	River Flood Warning	PHI	Montgomery	22 hr
Jul 11, 7:03 PM EDT	River Flood Warning	PHI	Chester, Montgomery, Philadelphia	26 hr
Jul 11, 7:19 PM EDT	River Flood Warning	PHI	Chester	7 hr
Jul 11, 7:47 PM EDT	Flash Flood Warning	PHI	Berks, Bucks, Lehigh, Montgomery	3 hr

Nearby

River Flood Warnings in Pennsylvania, 2019 Every river flood warning in 2019

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.