Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 214, NWS Philadelphia/Mount Holly

August 21, 20094 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 21, 2009, 1:29 PM EDT for 4 counties in Pennsylvania. It was in force for 76 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 21, 2009, 1:29 PM EDT (17:29 UTC)
Expired
Aug 21, 2009, 2:45 PM EDT
In force
76 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Carbon County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 132 km from the middle of the area, began a volume at 17:31 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.

What was reported inside it

TimeReportWhereRemark
Aug 21, 1:30 PM EDTTSTM WND DMG4 Sw Beltzville State P, PATREES DOWN IN MAHONING, FRANKLIN, AND TOWAMENSING TWPS.
Aug 21, 2:15 PM EDTTSTM WND DMG1 Ssw Emerald, PATREE LIMBS AND WIRES DOWN IN WASHINGTON AND UPPER SAUCON TWPS.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 21, 11:28 AM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 5.5 hours before the alert went out and 155 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, Phillips Aaf/Abe, MD at 12:00Z on 2009-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 96 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, Phillips Aaf/Abe, MD at 12:00Z on 2009-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 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
96 J/kg
Mixed-layer CIN
-66 J/kg
Mixed-layer LCL
930 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
108 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.6

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 211729
SVRPHI
PAC025-077-089-095-211845-
/O.NEW.KPHI.SV.W.0214.090821T1729Z-090821T1845Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
129 PM EDT FRI AUG 21 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
  NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA...
  SOUTHEASTERN CARBON COUNTY IN NORTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF LEHIGHTON...
  SOUTHERN MONROE COUNTY IN NORTHEAST PENNSYLVANIA...

* UNTIL 245 PM EDT

* AT 128 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  NEW TRIPOLI...OR 14 MILES SOUTH OF LEHIGHTON...AND MOVING NORTHEAST
  AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  NEW TRIPOLI AROUND 135 PM EDT...
  JORDAN VALLEY AROUND 140 PM EDT...
  JORDAN VALLEY AROUND 145 PM EDT...
  NEFFS AND SCHNECKSVILLE AROUND 150 PM EDT...
  WALNUTPORT...SLATINGTON AND EMERALD AROUND 155 PM EDT...
  PALMERTON AROUND 200 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM EDT FRIDAY
EVENING FOR NEW JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4087 7507 4052 7563 4069 7587 4074 7578
      4079 7585 4106 7532
TIME...MOT...LOC 1729Z 235DEG 24KT 4064 7579

$$

NIERENBERG
1 follow-up statement
000 
WWUS51 KPHI 211832
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
232 PM EDT FRI AUG 21 2009

PAC025-077-211842-
/O.CAN.KPHI.SV.W.0214.000000T0000Z-090821T1845Z/
LEHIGH PA-CARBON PA-
232 PM EDT FRI AUG 21 2009

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN CARBON AND LEHIGH
COUNTIES IS CANCELLED...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM EDT FRIDAY
EVENING FOR NEW JERSEY AND EASTERN PENNSYLVANIA. A SEVERE
THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 900 PM EDT FRIDAY
EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN NEW
JERSEY.

LAT...LON 4068 7548 4074 7553 4074 7559 4079 7560
      4081 7547 4106 7532 4087 7507 4066 7541
TIME...MOT...LOC 1832Z 235DEG 24KT 4088 7533

$$

PAC089-095-211845-
/O.CON.KPHI.SV.W.0214.000000T0000Z-090821T1845Z/
NORTHAMPTON PA-MONROE PA-
232 PM EDT FRI AUG 21 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 245 PM EDT
FOR SOUTH CENTRAL MONROE AND NORTHAMPTON COUNTIES...

AT 231 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED NEAR SAYLORSBURG...OR 15 MILES NORTHWEST OF EASTON...MOVING
NORTHEAST AT 30 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  PEN ARGYL...ROSETO AND BANGOR BY 240 PM EDT...
  STORMVILLE...EAST BANGOR AND 8 MILES SOUTHEAST OF REEDERS BY 245 PM
  EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM EDT FRIDAY
EVENING FOR NEW JERSEY AND EASTERN PENNSYLVANIA. A SEVERE
THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 900 PM EDT FRIDAY
EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN NEW
JERSEY.

&&

LAT...LON 4068 7548 4074 7553 4074 7559 4079 7560
      4081 7547 4106 7532 4087 7507 4066 7541
TIME...MOT...LOC 1832Z 235DEG 24KT 4088 7533

$$

NIERENBERG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 12:20 PM EDTSevere Thunderstorm WarningPHIBerks55 min
Aug 21, 12:55 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe35 min
Aug 21, 1:16 PM EDTSevere Thunderstorm WarningPHIBerks59 min
Aug 21, 1:52 PM EDTSevere Thunderstorm WarningPHIChester68 min
Aug 21, 1:55 PM EDTSevere Thunderstorm WarningPHIMonroe65 min
Aug 21, 2:41 PM EDTAreal Flood AdvisoryPHIMonroe, Northampton3 hr
Aug 21, 2:47 PM EDTFlash Flood WatchPHIBerks, Carbon, Delaware, Lehigh, Monroe, Northampton and 1 more35 hr

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2009Every severe thunderstorm warning in 2009

Sources

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