Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 250, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 11, 2021, 6:16 PM EDT for Berks County, Lehigh County, Montgomery County, Pennsylvania. It was in force for 44 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 11, 2021, 6:16 PM EDT (22:16 UTC)
- Expired
- Aug 11, 2021, 7:00 PM EDT
- In force
- 44 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Berks County, PA, Lehigh County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 125 km from the middle of the area, began a volume at 22:17 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 |
|---|---|---|---|
| Aug 11, 6:30 PM EDT | TSTM WND DMG | 2 W Oley, PA | TREE DOWN AT VICTORIA LN/BULL ROAD. TIME ESTIMATED FROM RADAR. |
| Aug 11, 6:32 PM EDT | TSTM WND DMG | 1 Nne Oley, PA | TREES AND WIRES DOWN IN OLEY TOWNSHIP ON WATER ROAD. TIME ESTIMATED FROM RADAR. |
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.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Aug 11, 3:02 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 10.3 hours before the alert went out and 232 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
- 553 J/kg
- Mixed-layer CIN
- -190 J/kg
- Mixed-layer LCL
- 1301 m above ground
- 0-6 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- 20 m²/s²
- 0-3 km storm-relative helicity
- 77 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
165
WUUS51 KPHI 112216
SVRPHI
PAC011-077-091-112300-
/O.NEW.KPHI.SV.W.0250.210811T2216Z-210811T2300Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
616 PM EDT Wed Aug 11 2021
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Northeastern Berks County in eastern Pennsylvania...
Central Lehigh County in eastern Pennsylvania...
Northwestern Montgomery County in southeastern Pennsylvania...
* Until 700 PM EDT.
* At 616 PM EDT, severe thunderstorms were located along a line
extending from near Lenhartsville to near Reading, moving east at
25 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
* Locations impacted include...
Allentown, Reading, Emmaus, Wyomissing, Kutztown, Fleetwood,
Laureldale, East Greenville, Topton, Bally, Bechtelsville, Lyons,
Lenhartsville, Coffeetown, Zionsville, Ancient Oaks, Claussville,
Gilbertsville, Catasauqua and West Reading.
This includes the following highways...
Northeast Extension between mile markers 50 and 62.
Interstate 78 in Pennsylvania between mile markers 36 and 58.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4062 7589 4068 7550 4066 7548 4066 7547
4043 7550 4033 7552 4034 7598
TIME...MOT...LOC 2216Z 251DEG 22KT 4058 7581 4034 7587
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
JEO2 follow-up statements
501
WWUS51 KPHI 112231
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
631 PM EDT Wed Aug 11 2021
PAC011-077-091-112300-
/O.CON.KPHI.SV.W.0250.000000T0000Z-210811T2300Z/
Berks PA-Lehigh PA-Montgomery PA-
631 PM EDT Wed Aug 11 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR NORTHEASTERN BERKS...CENTRAL LEHIGH AND NORTHWESTERN MONTGOMERY
COUNTIES...
At 631 PM EDT, severe thunderstorms were located along a line
extending from near Claussville to 6 miles southeast of Fleetwood,
moving east at 25 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
Locations impacted include...
Allentown, Reading, Emmaus, Kutztown, Fleetwood, Laureldale, East
Greenville, Topton, Bally, Bechtelsville, Lyons, Coffeetown,
Zionsville, Ancient Oaks, Claussville, Gilbertsville, Catasauqua,
Boyertown, Coplay and Macungie.
This includes the following highways...
Northeast Extension between mile markers 50 and 62.
Interstate 78 in Pennsylvania between mile markers 42 and 58.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4063 7579 4068 7550 4066 7548 4066 7547
4043 7550 4033 7552 4034 7590 4047 7591
4048 7585 4053 7581
TIME...MOT...LOC 2231Z 251DEG 22KT 4061 7571 4037 7577
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
JEO255
WWUS51 KPHI 112258
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
658 PM EDT Wed Aug 11 2021
PAC011-077-091-112308-
/O.EXP.KPHI.SV.W.0250.000000T0000Z-210811T2300Z/
Berks PA-Lehigh PA-Montgomery PA-
658 PM EDT Wed Aug 11 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN BERKS...CENTRAL
LEHIGH AND NORTHWESTERN MONTGOMERY COUNTIES WILL EXPIRE AT 700 PM
EDT...
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.
A Severe Thunderstorm Watch remains in effect until 900 PM EDT for
eastern and southeastern Pennsylvania.
LAT...LON 4063 7579 4068 7550 4066 7548 4066 7547
4043 7550 4033 7552 4034 7590 4047 7591
4048 7585 4053 7581
TIME...MOT...LOC 2258Z 251DEG 22KT 4066 7551 4042 7557
$$
JEOThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 10, 8:02 PM EDT | Severe Thunderstorm Warning | PHI | Delaware, Philadelphia | 43 min |
| Aug 10, 8:18 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware, Montgomery | 42 min |
| Aug 10, 8:36 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 39 min |
| Aug 10, 8:43 PM EDT | Areal Flood Advisory | PHI | Delaware, Montgomery, Philadelphia | 2 hr |
| Aug 11, 2:56 PM EDT | Excessive Heat Watch | PHI | Berks, Bucks, Chester, Lehigh, Montgomery, Northampton | 12 hr |
| Aug 11, 4:46 PM EDT | Special Weather Statement | PHI | Monroe | 44 min |
| Aug 11, 4:58 PM EDT | Special Weather Statement | PHI | Berks | 47 min |
| Aug 11, 5:20 PM EDT | Areal Flood Advisory | PHI | Carbon, Monroe | 57 min |
| Aug 11, 5:48 PM EDT | Severe Thunderstorm Warning | PHI | Berks | 57 min |
| Aug 11, 6:26 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester, Delaware, Montgomery | 49 min |
| Aug 11, 6:48 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Lehigh, Montgomery, Northampton | 42 min |
| Aug 11, 6:50 PM EDT | Areal Flood Advisory | PHI | Monroe, Northampton | 3 hr |
| Aug 11, 7:04 PM EDT | Areal Flood Advisory | PHI | Berks, Bucks, Chester, Delaware, Lehigh, Montgomery and 2 more | 2 hr |
| Aug 11, 7:11 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Chester, Delaware, Montgomery, Philadelphia | 49 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2021Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.