Alert archive / Pennsylvania / Special Weather Statements in 2021

Special Weather Statement, NWS Philadelphia/Mount Holly

September 23, 2021Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Sep 23, 2021, 12:57 PM EDT for Bucks County, Pennsylvania. It was in force for 33 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 23, 2021, 12:57 PM EDT (16:57 UTC)
Expired
Sep 23, 2021, 1:30 PM EDT
In force
33 min
Issued by
NWS Philadelphia/Mount Holly
Hail
0.00 in
Wind
40

County Bucks County, PA

The radar

The Philadelphia radar (KDIX), 89 km from the middle of the area, began a volume at 17:02 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

Brookhaven, NY (KOKX), launched 12:00Z, 5.0 hours before the alert went out and 215 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, Brookhaven, NY at 12:00Z on 2021-09-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 103 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, Brookhaven, NY at 12:00Z on 2021-09-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 249 square meters per square second.193958Sfc1 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
103 J/kg
Mixed-layer CIN
-11 J/kg
Mixed-layer LCL
687 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
249 m²/s²
0-3 km storm-relative helicity
201 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.1

Open this sounding in Storm Lab

The text

As transmitted.

748 
WWUS81 KPHI 231657
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
1257 PM EDT Thu Sep 23 2021
 
NJZ007-009-017-PAZ061-062-070-071-103>106-231730-
Hunterdon NJ-Warren NJ-Gloucester NJ-Lower Bucks PA-Upper Bucks PA-
Lehigh PA-Eastern Montgomery PA-Western Montgomery PA-Delaware PA-
Northampton PA-Philadelphia PA-
1257 PM EDT Thu Sep 23 2021

...Strong thunderstorms will impact portions of southwestern
Hunterdon, southwestern Warren, northwestern Gloucester, southeastern
Lehigh, central Montgomery, Bucks, northwestern Philadelphia, eastern
Delaware and southwestern Northampton Counties through 130 PM EDT...

At 1257 PM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from Geryville to near Chalfont to Darby Township.
Movement was north at 50 mph.

HAZARD...Wind gusts up to 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around 
         unsecured objects.

Locations impacted include...
Philadelphia, Allentown, Easton, Bethlehem, Norristown, Chester,
Lansdale, East Norriton, Yeadon, Emmaus, Northampton, Quakertown,
Perkasie, Doylestown, Byram, Wilson, Conshohocken, Hatboro, Souderton
and Folcroft.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 330 and 343.
 Northeast Extension between mile markers 21 and 26, and between mile
markers 28 and 54.
 Interstate 95 in Pennsylvania between mile markers 5 and 10.
 Interstate 76 in Pennsylvania between mile markers 330 and 340.
 Interstate 78 in Pennsylvania between mile markers 56 and 76.
 Interstate 295 in New Jersey between mile markers 11 and 12.
 Interstate 476 in Pennsylvania between mile markers 0 and 19.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

Torrential rainfall is also occurring with these storms and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 4056 7502 4039 7496 3976 7535 3990 7540
      4021 7532 4039 7558 4044 7553 4047 7557
      4082 7544
TIME...MOT...LOC 1657Z 200DEG 42KT 4044 7549 4023 7520 3990 7529 

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

$$

Staarmann

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 22, 8:43 PM EDTGale WarningPHI18 hr
Sep 23, 9:12 AM EDTCoastal Flood AdvisoryPHIBurlington, Camden, Gloucester10 hr
Sep 23, 11:33 AM EDTAreal Flood AdvisoryPHICumberland, Gloucester, Salem3 hr
Sep 23, 11:57 AM EDTFlash Flood WarningPHIGloucester, Salem3 hr
Sep 23, 12:12 PM EDTSevere Thunderstorm WarningPHIGloucester, Salem48 min
Sep 23, 12:54 PM EDTSpecial Weather StatementPHIGloucester51 min
Sep 23, 12:56 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Hunterdon, Mercer, Warren3 hr
Sep 23, 1:13 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester, Salem47 min
Sep 23, 1:42 PM EDTFlash Flood WarningPHIBurlington, Camden, Gloucester4 hr
Sep 23, 1:58 PM EDTSpecial Weather StatementPHICamden, Hunterdon32 min
Sep 23, 2:37 PM EDTAreal Flood AdvisoryPHIBurlington, Hunterdon, Mercer, Middlesex, Monmouth, Morris and 3 more3 hr
Sep 23, 2:47 PM EDTSpecial Weather StatementPHIHunterdon, Mercer28 min
Sep 23, 2:52 PM EDTSpecial Weather StatementPHICamden23 min
Sep 23, 3:13 PM EDTSpecial Weather StatementPHIMercer, Somerset32 min
Sep 23, 3:16 PM EDTSpecial Weather StatementPHIBurlington29 min
Sep 23, 3:23 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer, Middlesex, Morris, Somerset52 min
Sep 23, 3:26 PM EDTFlash Flood WarningPHIBurlington, Hunterdon, Mercer, Middlesex, Morris, Somerset2 hr
Sep 23, 3:50 PM EDTSpecial Weather StatementPHIBurlington25 min
Sep 23, 4:21 PM EDTAreal Flood AdvisoryPHIMiddlesex, Monmouth, Morris, Ocean, Somerset, Sussex15 min
Sep 23, 4:36 PM EDTFlash Flood WarningPHIMiddlesex, Monmouth, Morris, Somerset, Sussex3 hr
Sep 23, 5:00 PM EDTSpecial Weather StatementPHIMonmouth30 min
Sep 23, 10:52 AM EDTAreal Flood AdvisoryPHIChester3 hr
Sep 23, 11:40 AM EDTAreal Flood AdvisoryPHIBerks, Bucks, Carbon, Lehigh, Montgomery, Northampton3 hr
Sep 23, 12:28 PM EDTFlash Flood WarningPHIChester, Delaware, Montgomery, Philadelphia4 hr
Sep 23, 1:48 PM EDTRiver Flood WarningPHIChester5 hr
Sep 23, 4:26 PM EDTAreal Flood WarningPHIChester, Delaware, Montgomery, Philadelphia80 min
Sep 23, 7:18 PM EDTAreal Flood WarningPHIBerks, Montgomery36 min
Sep 23, 11:11 AM EDTSpecial Weather StatementPHINew Castle64 min
Sep 23, 11:42 AM EDTSevere Thunderstorm WarningPHINew Castle33 min
Sep 23, 8:08 AM EDTSpecial Weather StatementPHIKent, Queen Anne's, Talbot52 min
Sep 23, 9:03 AM EDTAreal Flood AdvisoryPHIKent, Queen Anne's, Talbot3 hr
Sep 23, 9:31 AM EDTSpecial Weather StatementPHIKent, Queen Anne's, Talbot59 min
Sep 23, 9:46 AM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's, Talbot44 min
Sep 23, 9:49 AM EDTFlash Flood WarningPHIKent, Queen Anne's, Talbot4 hr
Sep 23, 10:35 AM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's40 min
Sep 23, 10:55 AM EDTAreal Flood AdvisoryPHICaroline, Kent, Queen Anne's, Talbot3 hr

Nearby

Special Weather Statements in Pennsylvania, 2021Every special weather statement 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.