Alert archive / Pennsylvania / Areal Flood Advisories in 2008

Areal Flood Advisory 21, NWS Philadelphia/Mount Holly

August 10, 2008Berks County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this areal flood advisory at Aug 10, 2008, 5:25 PM EDT for Berks County, Montgomery County, Pennsylvania. It was in force for 110 min.

The area

The outline as issued.

The facts

Issued: Aug 10, 2008, 5:25 PM EDT (21:25 UTC)
Expired: Aug 10, 2008, 7:15 PM EDT
In force: 110 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Berks County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 112 km from the middle of the area, began a volume at 21:26 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 nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.4 hours before the alert went out and 206 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 771 J/kg
Mixed-layer CIN: -66 J/kg
Mixed-layer LCL: 923 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 3 m²/s²
0-3 km storm-relative helicity: 85 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.8

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WGUS81 KPHI 102125
FLSPHI

FLOOD ADVISORY
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
525 PM EDT SUN AUG 10 2008

PAC011-091-102315-
/O.NEW.KPHI.FA.Y.0021.080810T2125Z-080810T2315Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
525 PM EDT SUN AUG 10 2008

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED AN

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR...
  EASTERN BERKS COUNTY IN EASTERN PENNSYLVANIA...
  MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 715 PM EDT

* AT 522 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A 
  LINE OF SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN MOVING THROUGH   
  THE AREA FROM WEST TO EAST.

EXCESSIVE RUNOFF FROM THE HEAVY RAINFALL WILL CAUSE ELEVATED LEVELS 
ON SMALL CREEKS AND STREAMS...AND PONDING OF WATER IN URBAN 
AREAS...HIGHWAYS...STREETS AND UNDERPASSES AS WELL AS OTHER POOR 
DRAINAGE AREAS AND LOW LYING SPOTS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

A FLOOD ADVISORY MEANS RIVER OR STREAM FLOWS ARE ELEVATED OR PONDING
OF WATER IN URBAN OR OTHER AREAS IS OCCURRING OR IS IMMINENT.

LAT...LON 4024 7602 4056 7572 4019 7513 4004 7533
      4021 7555 4026 7569 4014 7589

$$

GORSE

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 10:18 AM EDT	Severe Thunderstorm Warning	PHI	Chester	57 min
Aug 10, 10:44 AM EDT	Severe Thunderstorm Warning	PHI	Delaware	61 min
Aug 10, 11:09 AM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	66 min
Aug 10, 11:32 AM EDT	Areal Flood Advisory	PHI	Chester, Delaware	3 hr
Aug 10, 11:46 AM EDT	Severe Thunderstorm Warning	PHI	Delaware	59 min
Aug 10, 12:09 PM EDT	Tornado Warning	PHI	Delaware	36 min
Aug 10, 12:17 PM EDT	Flash Flood Warning	PHI	Chester, Delaware, Montgomery	4 hr
Aug 10, 12:21 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Lehigh, Montgomery	84 min
Aug 10, 12:40 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Philadelphia	95 min
Aug 10, 1:05 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Carbon, Lehigh, Monroe, Northampton	115 min
Aug 10, 1:10 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	65 min
Aug 10, 1:47 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Montgomery	58 min
Aug 10, 3:05 PM EDT	Flash Flood Warning	PHI	Chester	3 hr
Aug 10, 3:35 PM EDT	Severe Thunderstorm Warning	PHI	Berks	40 min
Aug 10, 4:45 PM EDT	Severe Thunderstorm Warning	PHI	Chester	75 min
Aug 10, 5:45 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	75 min
Aug 10, 5:59 PM EDT	Areal Flood Advisory	PHI	Chester, Delaware	2 hr
Aug 10, 6:45 PM EDT	Areal Flood Advisory	PHI	Philadelphia	2 hr

Nearby

Areal Flood Advisories in Pennsylvania, 2008 Every areal flood advisory in 2008

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.