Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2018
Severe Thunderstorm Warning 100, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 26, 2018, 7:06 PM EDT for 4 counties in Pennsylvania; Cecil County, Kent County, Maryland; New Castle County, Delaware. It was in force for 54 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Sep 26, 2018, 7:06 PM EDT (23:06 UTC)
- Expired
- Sep 26, 2018, 8:00 PM EDT
- In force
- 54 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties New Castle County, DE, Cecil County, MD, Kent County, MD, Berks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Sep 26, 5:02 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 11.1 hours before the alert went out and 163 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
- 6 J/kg
- Mixed-layer CIN
- -201 J/kg
- Mixed-layer LCL
- 948 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 99 m²/s²
- 0-3 km storm-relative helicity
- 111 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
305
WUUS51 KPHI 262306
SVRPHI
DEC003-MDC015-029-PAC011-029-045-091-270000-
/O.NEW.KPHI.SV.W.0100.180926T2306Z-180927T0000Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
706 PM EDT WED SEP 26 2018
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Northwestern New Castle County in northern Delaware...
Northeastern Kent County in northeastern Maryland...
Cecil County in northeastern Maryland...
Southeastern Berks County in eastern Pennsylvania...
Montgomery County in southeastern Pennsylvania...
Chester County in southeastern Pennsylvania...
Western Delaware County in southeastern Pennsylvania...
* Until 800 PM EDT.
* At 705 PM EDT, severe thunderstorms were located along a line
extending from near Birdsboro to near Delta, moving east at 30 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...
Wilmington, Newark, West Chester, Elkton, Calvert, Norristown,
Pottstown, Phoenixville, Lansdale, West Norriton, East Norriton,
Coatesville, Westtown, Downingtown, Conshohocken, Souderton,
Ambler, Elsmere, Kennett Square and Birdsboro.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in Mount Holly NJ.
In addition to large hail and damaging winds, frequent cloud to
ground lightning is occurring with this storm. Move indoors
immediately. Remember, if you can hear thunder, you are close enough
to be struck by lightning.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 3973 7610 3987 7599 3995 7600 4004 7593
4011 7594 4014 7588 4022 7599 4044 7580
4030 7529 4022 7516 3936 7587 3936 7591
3941 7601 3952 7598 3955 7603 3955 7608
3972 7623
TIME...MOT...LOC 2305Z 290DEG 25KT 4030 7577 3969 7632
HAIL...0.75IN
WIND...60MPH
$$
MPS3 follow-up statements
156
WWUS51 KPHI 262334
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
734 PM EDT WED SEP 26 2018
DEC003-MDC015-029-PAC011-029-045-091-270000-
/O.CON.KPHI.SV.W.0100.000000T0000Z-180927T0000Z/
New Castle DE-Kent MD-Cecil MD-Berks PA-Montgomery PA-Chester PA-
Delaware PA-
734 PM EDT WED SEP 26 2018
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR NORTHWESTERN NEW CASTLE...NORTHEASTERN KENT...CECIL...
SOUTHEASTERN BERKS...MONTGOMERY...CHESTER AND WESTERN DELAWARE
COUNTIES...
At 734 PM EDT, severe thunderstorms were located along a line
extending from Pottstown to near Octoraro, moving east at 20 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
Locations impacted include...
Wilmington, Newark, West Chester, Elkton, Calvert, Norristown,
Pottstown, Phoenixville, Lansdale, West Norriton, East Norriton,
Coatesville, Westtown, Downingtown, Conshohocken, Souderton, Ambler,
Elsmere, Kennett Square and Birdsboro.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Mount Holly NJ.
In addition to large hail and damaging winds, frequent cloud to
ground lightning is occurring with this storm. Move indoors
immediately. Remember, if you can hear thunder, you are close enough
to be struck by lightning.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 3973 7610 3987 7599 3995 7600 4004 7593
4011 7594 4014 7588 4022 7599 4044 7580
4030 7529 4022 7516 3936 7587 3936 7591
3941 7601 3952 7598 3955 7603 3955 7608
3972 7623
TIME...MOT...LOC 2334Z 290DEG 18KT 4026 7565 3965 7620
HAIL...0.75IN
WIND...60MPH
$$
MPS928
WWUS51 KPHI 262347
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
747 PM EDT WED SEP 26 2018
DEC003-MDC029-PAC011-045-262355-
/O.CAN.KPHI.SV.W.0100.000000T0000Z-180927T0000Z/
New Castle DE-Kent MD-Berks PA-Delaware PA-
747 PM EDT WED SEP 26 2018
...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN NEW CASTLE...
NORTHEASTERN KENT...SOUTHEASTERN BERKS AND WESTERN DELAWARE COUNTIES
IS CANCELLED...
The storms which prompted the warning moved out of Berks county, and
are weakening and moving slowly. Therefore, the warning has been
cancelled.
A severe thunderstorm watch remains in effect until 1100 PM EDT for
northeastern Maryland...and eastern and southeastern Pennsylvania.
LAT...LON 3972 7623 3973 7610 3976 7606 3987 7599
3993 7600 3994 7598 3995 7600 4004 7593
4011 7594 4025 7567 4022 7541 3955 7603
3955 7608
TIME...MOT...LOC 2345Z 290DEG 25KT 4024 7558 3963 7613
$$
MDC015-PAC029-091-270000-
/O.CON.KPHI.SV.W.0100.000000T0000Z-180927T0000Z/
Cecil MD-Montgomery PA-Chester PA-
747 PM EDT WED SEP 26 2018
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR NORTHWESTERN CECIL...WEST CENTRAL MONTGOMERY AND CHESTER
COUNTIES...
At 745 PM EDT, severe thunderstorms were located along a line
extending from near Pottstown to near Octoraro, moving east at 30
mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Damage to roofs, siding, trees, and power lines is
possible.
Locations impacted include...
Calvert, Pottstown, Phoenixville, Coatesville, Downingtown,
Collegeville, Oxford, Royersford, Parkesburg, Trappe, West Grove,
Rising Sun, Honey Brook, Elverson, Glen Roy, Blake, West Nottingham,
Pughtown, Mount Vernon and Marshallton.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Mount Holly NJ.
In addition to large hail and damaging winds, frequent cloud to
ground lightning is occurring with this storm. Move indoors
immediately. Remember, if you can hear thunder, you are close enough
to be struck by lightning.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 3972 7623 3973 7610 3976 7606 3987 7599
3993 7600 3994 7598 3995 7600 4004 7593
4011 7594 4025 7567 4022 7541 3955 7603
3955 7608
TIME...MOT...LOC 2345Z 290DEG 25KT 4024 7558 3963 7613
HAIL...0.75IN
WIND...60MPH
$$
MPS018
WWUS51 KPHI 262354
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
754 PM EDT WED SEP 26 2018
MDC015-PAC029-091-270003-
/O.EXP.KPHI.SV.W.0100.000000T0000Z-180927T0000Z/
Cecil MD-Montgomery PA-Chester PA-
754 PM EDT WED SEP 26 2018
...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN CECIL...WEST
CENTRAL MONTGOMERY AND CHESTER COUNTIES WILL EXPIRE AT 800 PM EDT...
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore, the warning will
be allowed to expire. However gusty winds and heavy rain are still
possible with these thunderstorms.
A severe thunderstorm watch remains in effect until 1100 PM EDT for
northeastern Maryland...and eastern and southeastern Pennsylvania.
To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
in Mount Holly NJ.
A new Severe Thunderstorm Warning is now in effect for New Castle
county in Delaware, Cecil county in Maryland, and for Chester county
in Pennsylvania until 8:45 PM EDT.
LAT...LON 3972 7623 3973 7610 3976 7606 3987 7599
3993 7600 3994 7598 3995 7600 4004 7593
4011 7594 4025 7567 4022 7541 3955 7603
3955 7608
TIME...MOT...LOC 2353Z 290DEG 25KT 4023 7553 3962 7608
$$
MPSThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 25, 9:11 PM EDT | Areal Flood Warning | PHI | Philadelphia | 3 hr |
| Sep 26, 6:15 PM EDT | Special Weather Statement | PHI | Northampton | 30 min |
| Sep 26, 6:37 PM EDT | Special Weather Statement | PHI | Chester | 53 min |
| Sep 26, 6:41 PM EDT | Areal Flood Advisory | PHI | Carbon, Lehigh, Monroe, Northampton | 3 hr |
| Sep 26, 7:31 PM EDT | Areal Flood Advisory | PHI | Berks, Chester, Montgomery | 106 min |
| Sep 26, 7:53 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 52 min |
| Sep 26, 7:16 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Cecil, Kent, Queen Anne's, Talbot | 43 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2018Severe Thunderstorm Warnings in Maryland, 2018Severe Thunderstorm Warnings in Delaware, 2018Every severe thunderstorm warning in 2018
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.