Alert archive / Pennsylvania / Tornado Warnings in 2009

Tornado Warning 12, NWS Philadelphia/Mount Holly

August 2, 2009Bucks County, Pennsylvania; Mercer County, New Jersey

NWS Philadelphia/Mount Holly issued this tornado warning at Aug 2, 2009, 11:51 AM EDT for Bucks County, Pennsylvania; Mercer County, New Jersey. It was in force for 24 min. 1 report 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 2, 2009, 11:51 AM EDT (15:51 UTC)
Expired
Aug 2, 2009, 12:15 PM EDT
In force
24 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Mercer County, NJ, Bucks County, PA

What was reported inside it

TimeReportWhereRemark
Aug 2, 12:06 PM EDTTSTM WND DMGEwing, NJNUMEROUS TREES SHEARED.

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

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 3.9 hours before the alert went out and 179 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 2009-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 105 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 2009-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 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
105 J/kg
Mixed-layer CIN
-79 J/kg
Mixed-layer LCL
723 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
111 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

000 
WFUS51 KPHI 021551
TORPHI
NJC021-PAC017-021615-
/O.NEW.KPHI.TO.W.0012.090802T1551Z-090802T1615Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1151 AM EDT SUN AUG 2 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* TORNADO WARNING FOR...
  WESTERN MERCER COUNTY IN CENTRAL NEW JERSEY...
  THIS INCLUDES THE CITY OF TRENTON...
  SOUTHEASTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 1215 PM EDT

* AT 1149 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR NEWTOWN...
  OR 9 MILES WEST OF TRENTON...MOVING EAST AT 20 MPH.

* THE TORNADO WILL BE NEAR...
  WOODSIDE AND WASHINGTON CROSSING BY NOON EDT...
  EWING BY 1210 PM EDT...
  TRENTON AND WHITE HORSE BY 1215 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

WHEN A TORNADO WARNING IS ISSUED BASED ON DOPPLER RADAR...IT MEANS
THAT STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY
ALREADY BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY. IF YOU
ARE IN THE PATH OF THIS DANGEROUS STORM...MOVE INDOORS AND TO THE
LOWEST LEVEL OF THE BUILDING. STAY AWAY FROM WINDOWS. IF DRIVING...DO
NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.

&&

LAT...LON 4034 7475 4017 7470 4018 7495 4026 7497
TIME...MOT...LOC 1550Z 255DEG 18KT 4022 7493

$$

IOVINO

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 2, 2:19 AM EDTFlash Flood WatchPHIBerks, Carbon, Delaware, Lehigh, Monroe, Northampton and 1 more13 hr
Aug 2, 3:29 AM EDTAreal Flood AdvisoryPHIBerks3 hr
Aug 2, 5:54 AM EDTAreal Flood AdvisoryPHIChester3 hr
Aug 2, 7:34 AM EDTAreal Flood AdvisoryPHIBucks, Montgomery, Philadelphia3 hr
Aug 2, 7:51 AM EDTAreal Flood WarningPHIChester4 hr
Aug 2, 9:04 AM EDTAreal Flood WarningPHIMontgomery, Philadelphia4 hr
Aug 2, 9:06 AM EDTFlash Flood WarningPHIBerks, Carbon, Chester, Lehigh, Monroe, Northampton4 hr
Aug 2, 10:08 AM EDTFlash Flood WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia9 hr
Aug 2, 10:08 AM EDTSevere Thunderstorm WarningPHIChester67 min
Aug 2, 10:24 AM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery66 min
Aug 2, 10:53 AM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia67 min
Aug 2, 11:14 AM EDTSevere Thunderstorm WarningPHIBucks, Lehigh, Montgomery, Northampton61 min
Aug 2, 11:25 AM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia65 min
Aug 2, 11:48 AM EDTSevere Thunderstorm WarningPHIBucks57 min
Aug 2, 12:33 PM EDTRiver Flood WarningPHIBucks28 hr
Aug 2, 1:25 PM EDTAreal Flood WarningPHIMontgomery, Philadelphia6 hr
Aug 2, 4:06 PM EDTAreal Flood AdvisoryPHIBerks, Carbon, Lehigh, Monroe, Northampton4 hr
Aug 2, 4:21 PM EDTRiver Flood WarningPHIChester56 min
Aug 2, 4:22 PM EDTFlash Flood WarningPHIBerks2 hr
Aug 2, 6:15 PM EDTAreal Flood WarningPHIMontgomery, Philadelphia4 hr
Aug 2, 6:25 PM EDTAreal Flood WarningPHIPhiladelphia4 hr
Aug 2, 8:48 AM EDTAreal Flood WarningPHIMercer4 hr
Aug 2, 11:18 AM EDTFlash Flood WarningPHIHunterdon, Mercer, Middlesex, Morris, Somerset9 hr
Aug 2, 11:30 AM EDTSevere Thunderstorm WarningPHIAtlantic, Camden, Cape May, Cumberland, Gloucester, Salem60 min
Aug 2, 11:33 AM EDTSpecial Marine WarningPHI87 min
Aug 2, 12:13 PM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 3 more3 hr
Aug 2, 12:23 PM EDTSpecial Marine WarningPHI97 min
Aug 2, 12:27 PM EDTSevere Thunderstorm WarningPHIMorris, Somerset48 min
Aug 2, 12:45 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Monmouth60 min
Aug 2, 12:49 PM EDTRiver Flood WarningPHIMercer8 hr
Aug 2, 1:28 PM EDTSpecial Marine WarningPHI92 min
Aug 2, 1:43 PM EDTSevere Thunderstorm WarningPHICape May47 min
Aug 2, 1:49 PM EDTSpecial Marine WarningPHI86 min
Aug 2, 1:51 PM EDTSpecial Marine WarningPHI84 min
Aug 2, 1:56 PM EDTSpecial Marine WarningPHI2 hr
Aug 2, 1:59 PM EDTRiver Flood WarningPHIHunterdon, Somerset13 hr
Aug 2, 4:16 PM EDTRiver Flood WarningPHIMiddlesex, Somerset20 hr
Aug 2, 4:16 PM EDTRiver Flood WarningPHIMiddlesex, Somerset22 hr

Nearby

Tornado Warnings in Pennsylvania, 2009Tornado Warnings in New Jersey, 2009Every tornado warning in 2009Tornadoes 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.