Alert archive / Pennsylvania / Special Weather Statements in 2017

Special Weather Statement, NWS Philadelphia/Mount Holly

March 30, 2017Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Mar 30, 2017, 10:12 PM EDT for Montgomery 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
Mar 30, 2017, 10:12 PM EDT (02:12 UTC)
Expired
Mar 30, 2017, 10:45 PM EDT
In force
33 min
Issued by
NWS Philadelphia/Mount Holly

County Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 83 km from the middle of the area, began a volume at 02:13 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 00:00Z, 2.2 hours before the alert went out and 217 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 00:00Z on 2017-03-31Temperature 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, Brookhaven, NY at 00:00Z on 2017-03-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -25 square meters per square second.1939587897Sfc1 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
1601 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
-25 m²/s²
0-3 km storm-relative helicity
76 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

925 
WWUS81 KPHI 310212
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
1012 PM EDT THU MAR 30 2017

PAZ103>106-310245-
Lower Bucks-Upper Bucks-Eastern Montgomery-Western Montgomery-
1012 PM EDT THU MAR 30 2017

...A STRONG THUNDERSTORM PRODUCING PEA SIZE HAIL WILL AFFECT CENTRAL 
MONTGOMERY AND CENTRAL BUCKS COUNTIES...

At 1010 PM EDT, a strong thunderstorm was located near Schwenksville,
or 21 miles northwest of Philadelphia, moving east at 40 mph.

This storm has a history of producing pea size hail and cloud to 
ground lightning. Downpours will also occur.

This storm will be near...
  Souderton and Hatfield around 1015 PM EDT. 
  Lansdale and Fricks around 1020 PM EDT. 
  Ambler and Chalfont around 1025 PM EDT. 
  Doylestown around 1030 PM EDT. 
  Hatboro, Bryn Athyn, Ivyland and Willow Grove around 1035 PM EDT. 
  Richboro around 1040 PM EDT. 

Other locations impacted by this storm include Harleysville, Horsham,
Warminster Heights, Telford, Maple Glen, Brittany Farms-Highlands,
New Britain, North Wales, Spring House and Kulpsville.

LAT...LON 4022 7555 4033 7546 4033 7494 4013 7503
TIME...MOT...LOC 0210Z 275DEG 37KT 4024 7540 

$$

Gorse

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 31, 2:59 AM EDTCoastal Flood AdvisoryPHIMiddlesex, Monmouth, Ocean25 hr
Mar 31, 3:41 AM EDTFlood WatchPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 9 more20 hr
Mar 31, 4:36 PM EDTAreal Flood AdvisoryPHIMonmouth, Ocean4 hr
Mar 31, 4:50 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester, Salem9 hr
Mar 31, 5:20 PM EDTAreal Flood WarningPHIHunterdon, Somerset3 hr
Mar 31, 6:05 PM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Camden, Ocean3 hr
Mar 31, 6:30 PM EDTAreal Flood AdvisoryPHIMercer, Middlesex, Monmouth, Somerset7 hr
Mar 30, 10:57 PM EDTSpecial Weather StatementPHIBerks, Lehigh33 min
Mar 31, 7:16 PM EDTRiver Flood WarningPHIChester8 hr
Mar 31, 5:35 PM EDTRiver Flood WarningPHINew Castle8 hr

Nearby

Special Weather Statements in Pennsylvania, 2017Every special weather statement in 2017

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.