Alert archive / Maryland / River Flood Warnings in 2011

River Flood Warning 82, NWS Philadelphia/Mount Holly

April 17, 2011Cecil County, Harford County, Maryland

NWS Philadelphia/Mount Holly issued this river flood warning at Apr 17, 2011, 5:55 PM EDT for Cecil County, Harford County, Maryland. It took effect at Apr 18, 2011, 12:38 PM EDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued: Apr 17, 2011, 5:55 PM EDT (21:55 UTC)
In effect from: Apr 18, 2011, 12:38 PM EDT
Expired: Apr 18, 2011, 7:48 PM EDT
In force: 7 hr
Issued by: NWS Philadelphia/Mount Holly
Flood severity: Minor

Counties Cecil County, MD, Harford County, MD

The radar

The Dover AFB radar (KDOX), 100 km from the middle of the area, began a volume at 21:56 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 Susquehanna River at Conowingo Dam (CNWM2). The gauge peaked at 23.46 ft at Apr 18, 2011, 10:00 PM EDT.

Action stage: 21.5 ft
Minor stage: 23.5 ft
Moderate stage: 24.8 ft
Major stage: 28.5 ft

This gauge today: stage, forecast and historic crests

Stage from the USGS instantaneous record for site 01578310, 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.

064 
WGUS41 KPHI 172155
FLWPHI
BULLETIN - IMMEDIATE BROADCAST REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE MT HOLLY, NEW JERSEY
555 PM EDT SUN APR 17 2011

...THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A FLOOD 
WARNING FOR THE FOLLOWING RIVERS IN MARYLAND... 

  SUSQUEHANNA BELOW CONOWINGO DAM AFFECTING CECIL AND HARFORD COUNTIES

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SAFETY MESSAGE...DO NOT ATTEMPT TO DRIVE THROUGH FLOODED AREAS. THE 
WATER MAY BE DEEPER THAN YOU THINK.

&&

MDC015-025-180355-
/O.NEW.KPHI.FL.W.0082.110418T1902Z-000000T0000Z/
/CNWM2.1.ER.110418T1902Z.110418T2300Z.000000T0000Z.NO/
555 PM EDT SUN APR 17 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A 

* FLOOD WARNING FOR 
  THE SUSQUEHANNA BELOW CONOWINGO DAM.
* FROM MONDAY AFTERNOON UNTIL FURTHER NOTICE...OR UNTIL THE WARNING IS 
  CANCELLED.
* AT  5:30 PM SUNDAY THE STAGE WAS 22.4 FEET. 
* FLOOD STAGE IS 23.5 FEET. 
* MINOR FLOODING IS FORECAST. 
* FORECAST...RISE ABOVE FLOOD STAGE BY TOMORROW AFTERNOON AND CONTINUE 
  TO RISE TO NEAR 23.7 FEET BY TOMORROW EVENING.
* IMPACT...AT 23.7 FEET...NOTIFICATION LEVEL 4 WITH 18 TO 20 GATES OPEN 
  AT CONOWING DAM. MINOR FLOODING BEGINS IN THE TOWN OF PORT DEPOSIT 
  MARYLAND.

$$

                   FLD      OBSERVED          FORECAST
 LOCATION          STG    STG  DAY TIME       CREST

SUSQUEHANNA RIVER
  CONOWINGO DAM    23.5   22.41  SUN 5 PM    23.7  MON 7 PM 

&&

3 follow-up statements

479 
WGUS81 KPHI 180319
FLSPHI
FLOOD STATEMENT 
NATIONAL WEATHER SERVICE MT HOLLY, NEW JERSEY
1119 PM EDT SUN APR 17 2011

...THE FLOOD WARNING CONTINUES FOR THE FOLLOWING RIVERS IN MARYLAND...
 
  SUSQUEHANNA BELOW CONOWINGO DAM AFFECTING CECIL AND HARFORD COUNTIES 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SAFETY MESSAGE...DO NOT ATTEMPT TO DRIVE THROUGH FLOODED AREAS. THE 
WATER MAY BE DEEPER THAN YOU THINK.

&&

MDC015-025-181319-
/O.EXT.KPHI.FL.W.0082.110418T1315Z-000000T0000Z/
/CNWM2.1.ER.110418T1315Z.110419T0000Z.000000T0000Z.NO/
1119 PM EDT SUN APR 17 2011

THE FLOOD WARNING CONTINUES FOR
  THE SUSQUEHANNA BELOW CONOWINGO DAM.
* FROM MONDAY MORNING UNTIL FURTHER NOTICE.
* AT 10:30 PM SUNDAY THE STAGE WAS 23.1 FEET. 
* FLOOD STAGE IS 23.5 FEET. 
* MINOR FLOODING IS FORECAST.
* FORECAST...RISE ABOVE FLOOD STAGE BY LATE MONDAY MORNING AND 
  CONTINUE TO RISE TO NEAR 23.9 FEET BY MONDAY EVENING.
* IMPACT...AT 23.7 FEET...NOTIFICATION LEVEL 4 WITH 18 TO 20 GATES OPEN 
  AT CONOWING DAM. MINOR FLOODING BEGINS IN THE TOWN OF PORT DEPOSIT 
  MARYLAND.

$$

                   FLD      OBSERVED          FORECAST
 LOCATION          STG    STG  DAY TIME       CREST

SUSQUEHANNA RIVER
  CONOWINGO DAM    23.5   23.10  SUN 10 PM   23.9  MON 8 PM 

&&

317 
WGUS81 KPHI 181310
FLSPHI
FLOOD STATEMENT 
NATIONAL WEATHER SERVICE MT HOLLY, NEW JERSEY
910 AM EDT MON APR 18 2011

...THE FLOOD WARNING CONTINUES FOR THE FOLLOWING RIVERS IN MARYLAND...
 
  SUSQUEHANNA BELOW CONOWINGO DAM AFFECTING CECIL AND HARFORD COUNTIES 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SAFETY MESSAGE...DO NOT ATTEMPT TO DRIVE THROUGH FLOODED AREAS. THE 
WATER MAY BE DEEPER THAN YOU THINK.

&&

MDC015-025-182310-
/O.EXT.KPHI.FL.W.0082.110418T1638Z-000000T0000Z/
/CNWM2.1.ER.110418T1638Z.110418T1800Z.000000T0000Z.NO/
910 AM EDT MON APR 18 2011

THE FLOOD WARNING CONTINUES FOR
  THE SUSQUEHANNA BELOW CONOWINGO DAM.
* FROM THIS AFTERNOON UNTIL FURTHER NOTICE.
* AT 8:30 AM MONDAY THE STAGE WAS 22.9 FEET. 
* FLOOD STAGE IS 23.5 FEET. 
* MINOR FLOODING IS FORECAST.
* FORECAST...RISE ABOVE FLOOD STAGE BY THIS AFTERNOON AND CONTINUE TO 
  RISE TO NEAR 23.7 FEET BY THIS EVENING.
* IMPACT...AT 23.7 FEET...NOTIFICATION LEVEL 4 WITH 18 TO 20 GATES OPEN 
  AT CONOWING DAM. MINOR FLOODING BEGINS IN THE TOWN OF PORT DEPOSIT 
  MARYLAND.

$$

                   FLD      OBSERVED          FORECAST
 LOCATION          STG    STG  DAY TIME       CREST

SUSQUEHANNA RIVER
  CONOWINGO DAM    23.5   22.89  MON 8 AM    23.7  MON 2 PM 

&&

620 
WGUS81 KPHI 182348
FLSPHI
FLOOD STATEMENT 
NATIONAL WEATHER SERVICE MT HOLLY, NEW JERSEY
748 PM EDT MON APR 18 2011

...THE FLOOD WARNING IS CANCELLED FOR THE FOLLOWING RIVERS IN 
MARYLAND...
 
  SUSQUEHANNA BELOW CONOWINGO DAM AFFECTING CECIL AND HARFORD COUNTIES

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SAFETY MESSAGE...DO NOT ATTEMPT TO DRIVE THROUGH FLOODED AREAS. THE 
WATER MAY BE DEEPER THAN YOU THINK.

&&

MDC015-025-190018-
/O.CAN.KPHI.FL.W.0082.000000T0000Z-110418T2348Z/
/CNWM2.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.NO/
748 PM EDT MON APR 18 2011

THE FLOOD WARNING IS CANCELLED FOR
  THE SUSQUEHANNA BELOW CONOWINGO DAM.
* AT  7:30 PM MONDAY THE STAGE WAS 21.8 FEET. 
* FLOOD STAGE IS 23.5 FEET. 
* FORECAST...THE RIVER CRESTED BELOW FLOOD STAGE AT 23.2 FEET.  THE 
  RIVER WILL CONTINUE TO GRADUALLY FALL TONIGHT.
* IMPACT...AT 22.9 FEET...NOTIFICATION LEVEL 3 WITH 16 TO 17 GATES OPEN 
  AT CONOWINGO DAM. MARYLAND ROUTE 222 NORTH OF PORT DEPOSIT CLOSED.

$$

                   FLD      OBSERVED          FORECAST
 LOCATION          STG    STG  DAY TIME       CREST

SUSQUEHANNA RIVER
  CONOWINGO DAM    23.5   21.84  MON 7 PM    ALREADY CRESTED 

&&

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 16, 8:38 PM EDT	Severe Thunderstorm Warning	PHI	Caroline	52 min
Apr 16, 9:11 PM EDT	Severe Thunderstorm Warning	PHI	Cecil	64 min

Nearby

River Flood Warnings in Maryland, 2011 Every river flood warning in 2011

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.