Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2009
Severe Thunderstorm Warning 4, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Mar 29, 2009, 5:55 PM EDT for 5 counties in Pennsylvania. It was in force for 50 min. 5 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
- Mar 29, 2009, 5:55 PM EDT (21:55 UTC)
- Expired
- Mar 29, 2009, 6:45 PM EDT
- In force
- 50 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Bucks County, PA, Chester County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA
The radar
The Philadelphia radar (KDIX), 103 km from the middle of the area, began a volume at 21:56 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
| Time | Report | Where | Remark |
|---|---|---|---|
| Mar 29, 5:55 PM EDT | TSTM WND GST 50 | Pennsburg, PA | ESTIMATED 50 MPH WIND GUST WITH PEA SIZE HAIL REPORTED IN PENNSBURG. |
| Mar 29, 5:55 PM EDT | HAIL 0.88 | Allentown, PA | NICKEL SIZE HAIL REPORTED IN ALLENTOWN AND ACCUMULATING ON THE GROUND. |
| Mar 29, 6:15 PM EDT | TSTM WND DMG | Emmaus, PA | TREE DAMAGE REPORTED IN EMMAUS. |
| Mar 29, 6:15 PM EDT | HAIL 0.88 | Quakertown, PA | NICKEL SIZE HAIL REPORTED IN QUAKERTOWN. |
| Mar 29, 6:20 PM EDT | HAIL 1 | Pennsburg, PA | ONE INCH HAIL REPORTED IN PENNSBURG. ABOUT ONE INCH ACCUMULATION ALSO REPORTED. |
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, 9.9 hours before the alert went out and 220 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 424 m above ground
- 0-6 km bulk shear
- 48 kt
- 0-1 km storm-relative helicity
- 474 m²/s²
- 0-3 km storm-relative helicity
- 554 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
000
WUUS51 KPHI 292155
SVRPHI
PAC017-029-077-091-095-292245-
/O.NEW.KPHI.SV.W.0004.090329T2155Z-090329T2245Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
555 PM EDT SUN MAR 29 2009
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
EASTERN LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
THIS INCLUDES THE CITY OF ALLENTOWN...
CENTRAL NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA...
THIS INCLUDES THE CITY OF BETHLEHEM...
NORTHWESTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
NORTHEASTERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
NORTHERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
* UNTIL 645 PM EDT
* AT 552 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL. THIS
STORM WAS LOCATED NEAR EAST GREENVILLE...OR 15 MILES SOUTH OF
ALLENTOWN...AND MOVING NORTHEAST AT 40 MPH.
* THE SEVERE THUNDERSTORM WILL BE NEAR...
GERYVILLE AND ZIONSVILLE BY 600 PM EDT...
QUAKERTOWN BY 610 PM EDT...
SPRINGTOWN...PLEASANT VALLEY AND HELLERTOWN BY 620 PM EDT...
FERNDALE AND 6 MILES NORTHWEST OF REVERE BY 625 PM EDT...
OLD ORCHARD BY 630 PM EDT...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.
&&
LAT...LON 4043 7552 4070 7556 4080 7534 4058 7522
4035 7501 4014 7549 4026 7569
TIME...MOT...LOC 2155Z 232DEG 33KT 4040 7552
$$
STAUBERThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 29, 4:41 PM EDT | Severe Thunderstorm Warning | PHI | Berks | 94 min |
| Mar 29, 4:58 PM EDT | Tornado Warning | PHI | Berks | 62 min |
| Mar 29, 5:11 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Lehigh | 64 min |
| Mar 29, 5:27 PM EDT | Severe Thunderstorm Warning | PHI | Lehigh | 63 min |
| Mar 29, 6:11 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware, Montgomery, Philadelphia | 64 min |
| Mar 29, 7:09 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 51 min |
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.