Alert archive / Pennsylvania / Special Weather Statements in 2021
Special Weather Statement, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this special weather statement at Aug 19, 2021, 12:04 AM EDT for Bucks County, Delaware County, Montgomery County, Pennsylvania. It was in force for 71 min. 7 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 19, 2021, 12:04 AM EDT (04:04 UTC)
- Expired
- Aug 19, 2021, 1:15 AM EDT
- In force
- 71 min
- Issued by
- NWS Philadelphia/Mount Holly
- Hail
- 0.00 in
- Wind
- 50
Counties Bucks County, PA, Delaware County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 81 km from the middle of the area, began a volume at 04:03 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 19, 12:15 AM EDT | TSTM WND DMG | 2 Ese West Whiteland Tw, PA | SEVERAL REPORTS OF TREE AND POWER LINE DAMAGE IN THE DOWNINGTOWN, WEST CHESTER, AND EXTON AREAS, WITH SEVERAL ROADS CLOSED. TIME ESTIMATED FROM RADAR. |
| Aug 19, 12:25 AM EDT | TSTM WND DMG | 2 Wnw Chesterbrook, PA | DELAYED REPORT. SEVERAL REPORTS OF TREES DOWN BETWEEN MALVERN AND PHOENIXVILLE. TIME ESTIMATED FROM RADAR. |
| Aug 19, 12:25 AM EDT | TORNADO | 1 Wnw Hatfield, PA | EF1 WITH ESTIMATED PEAK WINDS UP TO 105 MPH. A LINE OF THUNDERSTORMS MOVED ACROSS MONTGOMERY AND BUCKS COUNTIES EARLY ON THE MORNING OF AUGUST 19TH AS THE REMNANTS OF TROPICAL STORM FRED MOVED ACROSS CENTRAL PENNSYLVANIA. WHAT STARTED AS A FAIRLY QUIET DAY FOR |
| Aug 19, 12:27 AM EDT | TSTM WND DMG | 1 Ese Souderton, PA | DOWNED TREES AND WIRES AND SOME DAMAGE TO HOMES IN THE AREA OF DEERFIELD DRIVE AND TOWNSHIP LINE ROAD. TIME ESTIMATED FROM RADAR. POSSIBLE TORNADO DAMAGE. |
| Aug 19, 12:33 AM EDT | TSTM WND DMG | 1 E Perkasie, PA | WIRES DOWN NEAR PERKASIE. LIKELY TORNADO DAMAGE. TIME BASED ON RADAR AND APPARENT TORNADO DEBRIS SIGNATURE. |
| Aug 19, 12:40 AM EDT | TSTM WND DMG | 1 Wsw North Wales, PA | DELAYED REPORT. LARGE TREE DOWN NEAR THE INTERSECTION OF 2ND STREET AND OAK STREET. TIME BASED ON DISPATCH REPORT. |
| Aug 19, 1:19 AM EDT | TSTM WND DMG | Fort Washington, PA | DELAYED REPORT. DOWNED TREE CLOSED ROUTE 309 NEAR HIGHLAND AVENUE. TIME ESTIMATED FROM RADAR. |
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 00:00Z, 4.1 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.
- Mixed-layer CAPE
- 491 J/kg
- Mixed-layer CIN
- -11 J/kg
- Mixed-layer LCL
- 580 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 62 m²/s²
- 0-3 km storm-relative helicity
- 103 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
300
WWUS81 KPHI 190404
SPSPHI
Special Weather Statement
National Weather Service Mount Holly NJ
1204 AM EDT Thu Aug 19 2021
DEZ001-PAZ070-101>106-190515-
New Castle DE-Lower Bucks PA-Upper Bucks PA-Eastern Montgomery PA-
Western Montgomery PA-Delaware PA-Western Chester PA-
Eastern Chester PA-
1204 AM EDT Thu Aug 19 2021
...Strong thunderstorms will impact portions of northern New Castle,
Montgomery, Bucks, central Chester and Delaware Counties through 115
AM EDT...
At 1204 AM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Revere to Fricks to near Collegeville to
West Chester. Movement was northeast at 35 mph.
HAZARD...Wind gusts up to 50 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Philadelphia, Wilmington, West Chester, Norristown, Chester,
Phoenixville, Lansdale, West Norriton, East Norriton, Westtown,
Quakertown, Perkasie, Doylestown, Byram, Downingtown, Conshohocken,
Hatboro, Souderton, Bedminster and Ambler.
This includes the following highways...
Pennsylvania Turnpike between mile markers 313 and 344.
Northeast Extension between mile markers 21 and 45.
Interstate 95 in Pennsylvania between mile markers 0 and 4.
Interstate 95 in Delaware between mile markers 13 and 23.
Interstate 76 in Pennsylvania between mile markers 327 and 337.
Interstate 476 in Pennsylvania between mile markers 1 and 19.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with these storms and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.
These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 4005 7567 4042 7548 4051 7538 4060 7520
4057 7518 4057 7511 4054 7507 4042 7506
4040 7497 4034 7494 4008 7517 4007 7519
4009 7522 4006 7526 4002 7523 3972 7549
3972 7593
TIME...MOT...LOC 0404Z 222DEG 31KT 4053 7513 4032 7525 4017 7541 3995
7564
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH
$$
MeolaThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 11:19 PM EDT | Areal Flood Advisory | PHI | Warren | 3 hr |
| Aug 19, 12:48 AM EDT | Tornado Warning | PHI | Hunterdon | 27 min |
| Aug 19, 1:32 AM EDT | Small Craft Advisory | PHI | 5 hr | |
| Aug 19, 2:05 AM EDT | Areal Flood Advisory | PHI | Hunterdon, Mercer, Morris, Somerset | 3 hr |
| Aug 19, 2:13 AM EDT | Flash Flood Warning | PHI | Burlington, Camden, Mercer | 4 hr |
| Aug 19, 2:33 AM EDT | Tornado Warning | PHI | Morris | 27 min |
| Aug 19, 2:40 AM EDT | Tornado Warning | PHI | Morris | 24 min |
| Aug 19, 3:09 AM EDT | Tornado Warning | PHI | Mercer, Middlesex, Monmouth | 36 min |
| Aug 19, 6:09 AM EDT | Areal Flood Warning | PHI | Mercer | 3 hr |
| Aug 18, 8:53 PM EDT | Areal Flood Advisory | PHI | Berks | 3 hr |
| Aug 18, 9:10 PM EDT | Areal Flood Advisory | PHI | Lehigh, Monroe, Northampton | 3 hr |
| Aug 18, 9:30 PM EDT | Flash Flood Warning | PHI | Berks | 2 hr |
| Aug 18, 9:35 PM EDT | Areal Flood Advisory | PHI | Berks, Lehigh | 3 hr |
| Aug 18, 9:45 PM EDT | Areal Flood Advisory | PHI | Berks | 3 hr |
| Aug 18, 9:47 PM EDT | Special Weather Statement | PHI | Berks | 58 min |
| Aug 18, 10:16 PM EDT | Flash Flood Warning | PHI | Berks, Lehigh | 3 hr |
| Aug 18, 10:44 PM EDT | Flash Flood Warning | PHI | Lehigh, Monroe, Northampton | 4 hr |
| Aug 18, 10:50 PM EDT | Flash Flood Warning | PHI | Bucks, Chester, Montgomery | 4 hr |
| Aug 18, 11:19 PM EDT | Special Weather Statement | PHI | Bucks, Chester, Montgomery | 41 min |
| Aug 18, 11:47 PM EDT | Flash Flood Warning | PHI | Chester | 2 hr |
| Aug 19, 12:26 AM EDT | Tornado Warning | PHI | Bucks, Montgomery | 34 min |
| Aug 19, 12:31 AM EDT | Flash Flood Warning | PHI | Bucks, Chester, Delaware, Montgomery | 4 hr |
| Aug 19, 12:44 AM EDT | River Flood Warning | PHI | Chester | 5 hr |
| Aug 19, 12:47 AM EDT | Tornado Warning | PHI | Chester, Delaware, Montgomery, Philadelphia | 28 min |
| Aug 19, 1:14 AM EDT | Special Weather Statement | PHI | Bucks, Delaware, Philadelphia | 91 min |
| Aug 19, 1:30 AM EDT | Flash Flood Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 4 hr |
| Aug 19, 4:33 AM EDT | Areal Flood Warning | PHI | Chester, Delaware | 4 hr |
| Aug 19, 8:50 AM EDT | Areal Flood Warning | PHI | Montgomery, Philadelphia | 3 hr |
| Aug 19, 10:40 AM EDT | Areal Flood Warning | PHI | Delaware | 3 hr |
| Aug 19, 3:22 PM EDT | Flash Flood Watch | PHI | Kent, Sussex | 23 hr |
Nearby
Special Weather Statements in Pennsylvania, 2021Every special weather statement 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.