Alert archive / Pennsylvania / River Flood Warnings in 2009

River Flood Warning 28, NWS Philadelphia/Mount Holly

December 9, 2009Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this river flood warning at Dec 9, 2009, 11:36 AM EST for Montgomery County, Pennsylvania. It took effect at Dec 9, 2009, 2:38 PM EST. It was in force for 2 hr.

The area

The counties it named.

The facts

Issued: Dec 9, 2009, 11:36 AM EST (16:36 UTC)
In effect from: Dec 9, 2009, 2:38 PM EST
Expired: Dec 9, 2009, 5:00 PM EST
In force: 2 hr
Issued by: NWS Philadelphia/Mount Holly
Flood severity: Minor

County Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 86 km from the middle of the area, began a volume at 16:39 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 10.57 ft at Dec 9, 2009, 1:00 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, in the capitals the NWS used until 2016.

000 
WGUS41 KPHI 091636
FLWPHI
BULLETIN - IMMEDIATE BROADCAST REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE MT HOLLY, NEW JERSEY
1136 AM EST WED DEC 09 2009

...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.

&&

PAC091-092236-
/O.NEW.KPHI.FL.W.0028.091209T1938Z-091210T0600Z/
/GRAP1.1.ER.091209T1938Z.091209T2100Z.091210T0000Z.NO/
1136 AM EST WED DEC 09 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A 

* FLOOD WARNING FOR 
  THE PERKIOMEN CREEK AT GRATERFORD.
* TO LATE TONIGHT...OR UNTIL THE WARNING IS CANCELLED.
* AT 11:15 AM WEDNESDAY THE STAGE WAS 10.1 FEET. 
* MINOR FLOODING IS FORECAST. 
* FLOOD STAGE IS 11.0 FEET. 
* FORECAST...RISE TO NEAR 11.5 FEET BY LATE THIS AFTERNOON. THE RIVER
  WILL FALL BELOW FLOOD STAGE BY THIS EVENING.
* IMPACT...AT 12.0 FEET...PENITENTIARY BRIDGE IS CLOSED. FLOODING BEGINS 
  IN COLLEGEVILLE. HOUSES ON THE RIGHT BANK IN GRATERFORD TAKE ON WATER

$$

                   FLD      OBSERVED          FORECAST
 LOCATION          STG    STG  DAY TIME       CREST

PERKIOMEN CREEK
  GRATERFORD       11.0   10.08  WED 11 AM   11.5  WED 4 PM 

&&

1 follow-up statement

000 
WGUS81 KPHI 092200
FLSPHI
FLOOD STATEMENT 
NATIONAL WEATHER SERVICE MT HOLLY, NEW JERSEY
500 PM EST WED DEC 09 2009

...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.

&&

PAC091-092230-
/O.CAN.KPHI.FL.W.0028.000000T0000Z-091210T0600Z/
/GRAP1.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.NO/
500 PM EST WED DEC 09 2009

* AT 4:30 PM WEDNESDAY THE STAGE WAS 10.3 FEET. 
* NO FLOODING IS CURRENTLY FORECAST.
* FLOOD STAGE IS 11.0 FEET. 
* IMPACT...AT 10.0 FEET...THE FIRST EVACUATIONS BEGIN IN SWENKSVILLE 
  UPSTREAM OF THE GAGE

$$

                   FLD      OBSERVED          FORECAST
 LOCATION          STG    STG  DAY TIME       CREST

PERKIOMEN CREEK
  GRATERFORD       11.0   10.26  WED 4 PM     FALLING 

&&

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 9, 6:53 AM EST	Areal Flood Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	8 hr
Dec 9, 7:47 AM EST	Areal Flood Warning	PHI	Bucks, Chester, Montgomery	7 hr
Dec 9, 8:16 AM EST	River Flood Warning	PHI	Bucks	12 hr
Dec 9, 8:25 AM EST	River Flood Warning	PHI	Delaware	5 hr
Dec 9, 9:58 AM EST	Areal Flood Advisory	PHI	Berks, Lehigh, Northampton	3 hr
Dec 9, 10:19 AM EST	River Flood Warning	PHI	Chester	7 hr
Dec 9, 10:40 AM EST	River Flood Warning	PHI	Chester, Delaware	13 hr
Dec 9, 12:00 PM EST	Wind Advisory	PHI	Berks, Carbon, Delaware, Lehigh, Monroe, Northampton and 1 more	33 hr
Dec 9, 1:15 PM EST	Areal Flood Warning	PHI	Berks	4 hr
Dec 9, 2:26 PM EST	Coastal Flood Advisory	PHI	Delaware, Philadelphia	7 hr
Dec 9, 2:55 PM EST	Areal Flood Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	7 hr

Nearby

River Flood Warnings in Pennsylvania, 2009 Every river flood warning in 2009

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.