Alert archive / Pennsylvania / Areal Flood Warnings in 2022

Areal Flood Warning 21, NWS Philadelphia/Mount Holly

May 7, 2022Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this areal flood warning at May 7, 2022, 12:23 PM EDT for Montgomery County, Pennsylvania. It was in force for 5 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
May 7, 2022, 12:23 PM EDT (16:23 UTC)
Expired
May 7, 2022, 5:41 PM EDT
In force
5 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

County Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 106 km from the middle of the area, began a volume at 16:23 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, 4.4 hours before the alert went out and 228 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 12:00Z on 2022-05-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2022-05-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
461 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
268 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

537 
WGUS41 KPHI 071623
FLWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mount Holly NJ
1223 PM EDT Sat May 7 2022

PAC091-072030-
/O.NEW.KPHI.FA.W.0021.220507T1623Z-220507T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery PA-
1223 PM EDT Sat May 7 2022

...FLOOD WARNING IN EFFECT UNTIL 430 PM EDT THIS AFTERNOON...

* WHAT...Flooding caused by excessive rainfall is expected.

* WHERE...A portion of southeast Pennsylvania...including the 
  following county...Montgomery.

* WHEN...Until 430 PM EDT.

* IMPACTS...Flooding of rivers, creeks, streams, and other low-lying 
  and flood-prone locations is imminent or occurring.

* ADDITIONAL DETAILS...
  - At 1221 PM EDT, Doppler radar indicated heavy rain. Flooding
    is ongoing or expected to begin shortly in the warned area.
    The Perkiomen Creek at East Greenville has exceeded flood
    stage and will likely remain above flood stage for several
    hours. Between 1.5 and 2.5 inches of rain have fallen.
  - For Perkiomen Creek at East Greenville:
    At 12:16pm the stage was 5.09 feet.
    Flood Stage is 5 feet.
    ...
    For West Branch Perkiomen Creek at Hillegass:
    At 11:15am the stage was 2.28 feet.
    Flood Stage is 5 feet.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

&&

LAT...LON 4042 7554 4043 7551 4036 7547 4035 7552


$$

JEO
2 follow-up statements
037 
WGUS41 KPHI 072017
FLWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mount Holly NJ
417 PM EDT Sat May 7 2022

PAC091-072200-
/O.EXT.KPHI.FA.W.0021.000000T0000Z-220507T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery PA-
417 PM EDT Sat May 7 2022

...FLOOD WARNING NOW IN EFFECT UNTIL 6 PM EDT THIS EVENING...

* WHAT...Flooding caused by excessive rainfall continues.

* WHERE...A portion of southeast Pennsylvania...including the 
  following county...Montgomery.

* WHEN...Until 600 PM EDT.

* IMPACTS...Flooding of rivers, creeks, streams, and other low-lying 
  and flood-prone locations is imminent or occurring.

* ADDITIONAL DETAILS...
  - At 416 PM EDT, Doppler radar indicated heavy rain. Flooding
    is occurring on the Perkiomen Creek at East Greenville.
    Between 2 and 2.5 inches of rain have fallen.
  - For Perkiomen Creek at East Greenville:
    At 3:47pm the stage was 5.69 feet.
    Flood Stage is 5 feet.
    ...
    For West Branch Perkiomen Creek at Hillegass:
    At 3:15pm the stage was 2.5 feet.
    Flood Stage is 5 feet.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

&&

LAT...LON 4042 7554 4043 7551 4036 7547 4035 7552


$$

JEO
683 
WGUS81 KPHI 072141
FLSPHI

Flood Statement
National Weather Service Mount Holly NJ
541 PM EDT Sat May 7 2022

PAC091-072151-
/O.CAN.KPHI.FA.W.0021.000000T0000Z-220507T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery PA-
541 PM EDT Sat May 7 2022

...FLOOD WARNING IS CANCELLED...

The Flood Warning is cancelled for Northwestern Montgomery County.

Flood waters have receded. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 4042 7554 4043 7551 4036 7547 4035 7552


$$

JEO

The office that day

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

IssuedProductOfficeCountiesLasted
May 7, 4:36 AM EDTCoastal Flood AdvisoryPHIBucks, Delaware, Philadelphia3 days
May 7, 10:39 AM EDTAreal Flood AdvisoryPHIBerks, Bucks, Chester, Lehigh, Montgomery, Northampton5 hr
May 7, 12:14 PM EDTAreal Flood AdvisoryPHICarbon, Lehigh, Monroe, Northampton4 hr

Nearby

Areal Flood Warnings in Pennsylvania, 2022Every areal flood warning in 2022

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.