Alert archive / Pennsylvania / Areal Flood Advisories in 2021

Areal Flood Advisory 162, NWS Philadelphia/Mount Holly

August 28, 2021Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this areal flood advisory at Aug 28, 2021, 2:47 AM EDT for Berks County, Pennsylvania. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Aug 28, 2021, 2:47 AM EDT (06:47 UTC)
Expired
Aug 28, 2021, 5:00 AM EDT
In force
2 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

County Berks County, PA

The radar

The Philadelphia radar (KDIX), 151 km from the middle of the area, began a volume at 06:48 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 00:00Z, 6.8 hours before the alert went out and 205 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-pSkew-T log-p diagram, Washington/Dulle, VA at 00:00Z on 2021-08-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 711 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2021-08-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
711 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
1370 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
99 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

232 
WGUS81 KPHI 280647
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
247 AM EDT Sat Aug 28 2021

PAC011-280900-
/O.NEW.KPHI.FA.Y.0162.210828T0647Z-210828T0900Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-
247 AM EDT Sat Aug 28 2021

The National Weather Service in Mount Holly has issued a

* Flood Advisory for...
  Berks County in eastern Pennsylvania...

* Until 500 AM EDT.

* At 247 AM EDT, Doppler radar indicated heavy rain due to 
  thunderstorms. Between 0.5 and 1 inch of rain has fallen. Combined 
  with the heavy rainfall much of this area received last evening, 
  these storms will likely produce areas of poor-drainage and urban 
  flooding.

* Some locations that may experience flooding include...
  Reading, Wyomissing, Birdsboro, Hamburg, Fleetwood, Sinking 
  Spring, Laureldale, Womelsdorf, Wernersville, Robesonia, Leesport, 
  and Shoemakersville.

This includes the following highways...
	Pennsylvania Turnpike between mile markers 296 and 300.
	Interstate 78 in Pennsylvania between mile markers 10 and 35.
	Interstate 176 in Pennsylvania between mile markers 1 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 4065 7596 4025 7569 4014 7587 4036 7621
      4037 7623 4050 7644 4054 7617 4058 7604
      4057 7602 4064 7599

$$

CMS
2 follow-up statements
674 
WGUS81 KPHI 280745
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
345 AM EDT Sat Aug 28 2021

PAC011-280900-
/O.CON.KPHI.FA.Y.0162.000000T0000Z-210828T0900Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-
345 AM EDT Sat Aug 28 2021

...FLOOD ADVISORY REMAINS IN EFFECT UNTIL 5 AM EDT EARLY THIS 
MORNING FOR SOUTHERN BERKS COUNTY...

At 345 AM EDT, local law enforcement reported heavy rain in the 
advisory area due to thunderstorms. Minor flooding is already 
occurring in Spring Township. Between 1 and 2 inches of rain have 
fallen.

Some locations that may experience flooding include...
  Reading, Wyomissing, Birdsboro, Fleetwood, Sinking Spring, 
  Laureldale, Womelsdorf, Wernersville, Robesonia, Leesport, 
  Shoemakersville, and Bernville.

This includes the following highways...
	Pennsylvania Turnpike between mile markers 296 and 299.
	Interstate 176 in Pennsylvania between mile markers 1 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 4052 7587 4025 7569 4022 7575 4021 7576
      4019 7579 4018 7581 4014 7587 4034 7619
      4036 7621 4036 7622 4037 7623 4050 7600

$$

CMS
643 
WGUS81 KPHI 280853
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
453 AM EDT Sat Aug 28 2021

PAC011-280903-
/O.EXP.KPHI.FA.Y.0162.000000T0000Z-210828T0900Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Berks PA-
453 AM EDT Sat Aug 28 2021

...FLOOD ADVISORY WILL EXPIRE AT 5 AM EDT EARLY THIS MORNING FOR 
SOUTHERN BERKS COUNTY...

The threat for widespread flooding has increased over the area. 
Therefore the Flood Advisory has been replaced by a Flash Flood 
Warning. Please refer to that bulletin for more information.

LAT...LON 4052 7587 4025 7569 4022 7575 4021 7576
      4019 7579 4018 7581 4014 7587 4034 7619
      4036 7621 4036 7622 4037 7623 4050 7600

$$

CMS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 28, 3:06 AM EDTAreal Flood AdvisoryPHIChester, Delaware, Montgomery, Philadelphia2 hr
Aug 28, 4:06 AM EDTFlash Flood WarningPHIBerks3 hr
Aug 28, 8:07 AM EDTAreal Flood AdvisoryPHIBucks, Montgomery, Northampton3 hr
Aug 28, 9:06 AM EDTFlash Flood WarningPHIBucks, Montgomery, Northampton3 hr
Aug 28, 11:57 AM EDTFlash Flood WarningPHIDelaware, Montgomery, Philadelphia3 hr

Nearby

Areal Flood Advisories in Pennsylvania, 2021Every areal flood advisory in 2021

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.