Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 250, NWS Philadelphia/Mount Holly

July 21, 2019Berks County, Chester County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 21, 2019, 10:42 PM EDT for Berks County, Chester County, Montgomery County, Pennsylvania. It was in force for 48 min. 3 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
Jul 21, 2019, 10:42 PM EDT (02:42 UTC)
Expired
Jul 21, 2019, 11:30 PM EDT
In force
48 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Berks County, PA, Chester County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 147 km from the middle of the area, began a volume at 02:44 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

TimeReportWhereRemark
Jul 21, 10:50 PM EDTTSTM WND DMG1 Sse Cedarville, PADOWNED TREE ON ROUTE 100 NEAR TEMPLE ROAD. TIME ESTIMATED FROM RADAR.
Jul 21, 10:55 PM EDTTSTM WND DMGExeter Twp, PAREPORTS OF DOWNED TREES IN EXETER TWP. TIME ESTIMATED FROM RADAR.
Jul 21, 11:16 PM EDTTSTM WND DMG2 Wsw Lower Frederick T, PAA FOUR-FOOT DIAMETER TREE WAS BLOWN DOWN ACROSS GERLOFF ROAD NEAR RYANFORD ROAD. TIME ESTIMATED FROM RADAR.

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

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 3 storm reports to this severe thunderstorm warning; the first came 8 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 2.7 hours before the alert went out and 195 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, Washington/Dulle, VA at 00:00Z on 2019-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 157 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2019-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -73 square meters per square second.1939Sfc1 km3 km6 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
157 J/kg
Mixed-layer CIN
-308 J/kg
Mixed-layer LCL
1994 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-73 m²/s²
0-3 km storm-relative helicity
-77 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

668 
WUUS51 KPHI 220242
SVRPHI
PAC011-029-091-220330-
/O.NEW.KPHI.SV.W.0250.190722T0242Z-190722T0330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
1042 PM EDT Sun Jul 21 2019

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Berks County in eastern Pennsylvania...
  Northwestern Montgomery County in southeastern Pennsylvania...
  Northeastern Chester County in southeastern Pennsylvania...

* Until 1130 PM EDT.

* At 1042 PM EDT, severe thunderstorms were located along a line
  extending from near Strausstown to near Lionville, moving northeast
  at 20 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Reading, Pottstown, Phoenixville, Wyomissing, Downingtown,
  Souderton, Birdsboro, Collegeville, Royersford, Fleetwood, Sinking
  Spring, Laureldale, Trappe, Womelsdorf, Wernersville, Newmanstown,
  Robesonia, Leesport, Schwenksville and Shoemakersville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

In addition to large hail and damaging winds, frequent cloud to
ground lightning is occurring with these storms. 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 4052 7634 4052 7625 4053 7620 4050 7593
      4032 7532 3997 7566 4012 7591 4014 7588
      4036 7621 4037 7623 4049 7643
TIME...MOT...LOC 0242Z 219DEG 16KT 4046 7619 4007 7567 

HAIL...<.75IN
WIND...60MPH
 
$$

CMS
2 follow-up statements
654 
WWUS51 KPHI 220258
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1058 PM EDT Sun Jul 21 2019

PAC011-029-091-220330-
/O.CON.KPHI.SV.W.0250.000000T0000Z-190722T0330Z/
Berks PA-Montgomery PA-Chester PA-
1058 PM EDT Sun Jul 21 2019

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1130 PM EDT
FOR BERKS...NORTHWESTERN MONTGOMERY AND NORTHEASTERN CHESTER
COUNTIES...

At 1058 PM EDT, severe thunderstorms were located along a line
extending from near Strausstown to near Laureldale to Chester
Springs, moving northeast at 20 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Reading, Pottstown, Phoenixville, Wyomissing, Souderton, Birdsboro,
Collegeville, Royersford, Fleetwood, Sinking Spring, Laureldale,
Trappe, Womelsdorf, Wernersville, Newmanstown, Robesonia, Leesport,
Schwenksville, Shoemakersville and Bally.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Continuous cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. 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 4052 7634 4052 7625 4053 7620 4050 7593
      4032 7532 4001 7562 4020 7579 4027 7607
      4032 7615 4036 7621 4037 7623 4049 7643
TIME...MOT...LOC 0258Z 216DEG 16KT 4051 7614 4036 7583 4012 7562 

HAIL...<.75IN
WIND...60MPH
 
$$

CMS
109 
WWUS51 KPHI 220321
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1121 PM EDT Sun Jul 21 2019

PAC011-029-091-220330-
/O.EXP.KPHI.SV.W.0250.000000T0000Z-190722T0330Z/
Berks PA-Montgomery PA-Chester PA-
1121 PM EDT Sun Jul 21 2019

...THE SEVERE THUNDERSTORM WARNING FOR BERKS...NORTHWESTERN
MONTGOMERY AND NORTHEASTERN CHESTER COUNTIES WILL EXPIRE AT 1130 PM
EDT...
    
The storms which prompted the warning are moving out of the area.
Therefore, the warning will be allowed to expire.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Mount Holly NJ.

LAT...LON 4052 7634 4052 7625 4053 7620 4050 7593
      4032 7532 4001 7562 4020 7579 4027 7607
      4032 7615 4036 7621 4037 7623 4049 7643
TIME...MOT...LOC 0320Z 219DEG 16KT 4058 7606 4043 7575 4019 7554 

$$

CMS

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Philadelphia/Mount Holly wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 21, 9:41 PM EDT, 1 hour 1 minute earlier.

Area forecast discussion, Jul 21, 9:41 PM EDT, 1 hour 1 minute before
Area Forecast Discussion
National Weather Service Mount Holly NJ
941 PM EDT Sun Jul 21 2019

.SYNOPSIS...
Low pressure is expected to develop in the Ohio River Valley
tonight before drifting eastward across northeastern Maryland,
eastern Pennsylvania, Delaware and New Jersey on Monday
afternoon and Monday evening. As the low continues toward Nova
Scotia on Tuesday it is anticipated to pull a cold front slowly
through our region. High pressure is forecast to build in from
the west on Wednesday and Thursday. The center of the high is
expected to slide off the coast next weekend but will still
continue to influence our weather.

&&

.NEAR TERM /THROUGH MONDAY/...
930 pm update: Very busy this evening. Pulse storms have
occurred in much of the CWA along/north of Interstate 78.
Several microbursts have occurred with these storms, including a
particularly damaging one in Somerset and Middlesex Counties
between 7 and 7:30 pm. Storms currently in northwest New Jersey
into the Lehigh Valley are exhibiting similar characteristics,
with some wind damage now being reported in Lehigh County in the
past half hour. Meanwhile, other storms in northern Maryland
with a history of severe weather are beginning to move toward
the Eastern Shore. Latest model trends suggest a diminishing
trend should occur around/after midnight, but given the
lackluster performance this evening, not overly confident. The
environment remains very warm and very moist and is quite
favorable for mixing stronger downbursts to the surface given
reasonable midlevel lapse rates and quite good low-level lapse
rates.

Main changes to the overnight forecast were to accommodate
(somehow) for hourly temperatures and dew points, which are
quite chaotic owing to the sporadic convection. Otherwise, the
forecast is holding quite well.

Excessive heat warning will be allowed to expire at 10 pm.

Previous discussion...

As of 3 PM, the cold front, which will be around the region for
the next 36 hours or so, was across central and NE PA. This
front should slowly start to sink south into our region
overnight and continuing through the day on Monday.

There are two main rounds of showers and thunderstorms we will
be watching over the next day. First, there could be a round of
isolated or maybe scattered convection into this evening. The
second and more significant round is expected Monday afternoon
continuing into Monday evening.

Through this evening: More widespread convection will develop
along the front and a few of those cells may drift into our
region. More likely is that we will see additional convective
development along gust fronts from other showers and
thunderstorms. As we saw Saturday evening, there is a potential
for strong to severe winds, but given how limited the coverage
could be of showers and thunderstorms, the severe threat is
marginal.

Monday afternoon into evening: As the front slips into our
region tomorrow, it could make it as far southeast as the I95
corridor before stalling. Additionally, a mid and upper level
short wave trough will be digging southeast towards the region.
Expect convective initiation to begin along the front around mid
day. Thanks to the warm and humid air mass ahead of the front,
expect CAPE values well above 1000 J/kg. There could also be a
cap in place depending on how warm we get before convective
initiation starts. In the vicinity of the front, bulk shear
values of 30 kt will be possible.

Monday hazards: The primary hazard looks to be damaging winds
as combination of high DCAPE values and potential for precip
loading increases the risk for downbursts. I can't rule out the
potential for tornadoes, primarily right along the front.
However, higher than normal LCLs should limit this threat. In
addition to the damaging winds, the other concern is heavy rain
leading to flash flooding. High precipitable water values and a
relatively deep warm cloud layer increase the threat for heavy
rain. In addition, given how slow moving the front will be,
there is a potential for training of showers and thunderstorms.

Heat: Though we will see some relief from the heat, heat index
values above 100 will once again be possible for locations that
will be south of the front. This primarily includes Delmarva and
far south Jersey. Therefore, have issued a heat advisory that
begins once the excessive heat warning expires late this evening
for those locations.

&&

.SHORT TERM /MONDAY NIGHT/...
Front will continue to slowly progress through the region. At this
time, have trended with a more progressive solution given the trends
of the cold front so far (although I still expect it to stall, at
least for a while over our region). Once we get past the evening
hours tomorrow, the severe wind threat should diminish. However, the
heavy rain/flash flooding threat will continue through Monday night.
Given the more progressive trends, the axis of highest QPF has also
been shifted SE. This would be good news if the threat for heaviest
rain is southeast of the urban corridor as the axis of highest QPF
would now be over an area with higher flash flood guidance.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Tuesday through Wednesday...

By early Tuesday morning, frontal boundary will be situated SW to NE
extending from the southern Delmarva off the coast of NJ which will
mean the area will be on the cool side of the boundary. However
upper level trough will continue to lag just off to the west with at
least one more impulse likely to come through. For this reason, one
more round of rain/showers and possible thunder is likely for
Tuesday morning mainly from around I-95 and points S/E. The rain
should not be as heavy as what could occur Monday/Monday night but
could still exacerbate any flooding issues that may be ongoing due
to earlier heavy rain. Temperatures will be much cooler with highs
in the 70s to around 80 and dew points in the 60s.

More appreciable clearing finally occurs Tuesday night as the front
continues to push off the coast and high pressure continues to
approach from the west. This surface ridging will nose into western
PA into upstate NY during the day Wednesday. However as the upper
trough axis moves through this along with daytime heating will
result in some daytime Cu but these should be of the fair weather
variety. Temperatures will be near if not a little below average for
this time of year with comfortable levels of humidity.

Wednesday night through Sunday....

A stretch of fair weather looks to finally take hold for the long
term as high pressure should dominate. This will mean mainly sunny
skies with seasonable temperatures and comfortable humidity levels
for Thursday and Friday as the high sets up right near the area.

By next weekend, as the high moves off the coast, a SW flow looks to
kick in so temperatures and dew points may start to nudge back up a
bit. However it doesn't look like a repeat of the current hot
stretch as heat indicies should not be nearly as high. Also, at this
point conditions look to remain mainly clear and free of precip
through next weekend.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Overnight...Cannot rule out storms through at least early
morning, especially at RDG/ABE/TTN and ILG given current radar
trends. Impacts would be fairly brief, but temporary
restrictions and gusty/erratic winds should be expected if
storms are nearby. Outside of storms, VFR with light/variable
winds.

Monday...Starting VFR conditions, but expect showers and
thunderstorms to develop between 15 and 18Z, and widespread
showers and thunderstorms are possible between 18 and 03Z. MVFR
or even IFR conditions will be possible with storms.
Gusty/erratic winds and torrential rainfall should be expected
with any storms. Winds will be quite variable in proximity to a
front moving slowly through the area, with speeds generally up
to 10 kt outside of storms.

OUTLOOK...
Monday night...Another round of showers and thunderstorms are
possible, especially south and east of the cold front, with MVFR
or IFR conditions possible. Otherwise, expect VFR conditions and
a shift to northerly or northwesterly winds with the front.

Tuesday...MVFR and IFR conditions in the morning due to lingering
low clouds and showers...especially from KILG through KPHL/KPNE and
KTTN and points S/E. Mainly VFR in the afternoon with a chance of
showers. N/NW wind around 10 knots.

Tuesday night...Mainly VFR. Northwest wind 5 to 10 knots.

Wednesday...Mainly VFR. Northwest wind around 10 knots.

Wednesday night and Thursday...Mainly VFR. Variable wind 10 knots or
less.

Friday...VFR.

&&

.MARINE...
Winds are forecast to remain south to southwesterly around
10-15 kts with gusts possibly up to 20 kts through tonight.
Seas 2-3 ft over the ocean and 2 ft or less over Delaware Bay.

OUTLOOK...
Monday night...a brief period of SCA conditions are possible,
especially just ahead of the cold front on Monday night.

Tuesday through Friday...Seas may be close to Small Craft
Advisory levels early Tuesday but otherwise no marine headlines
are anticipated.

RIP CURRENTS...
Wind will be southwesterly around 10-15 knots today, while seas
will remain 2-3 feet with a swell period of around 6 seconds.
This will keep a low risk of rip currents.

An increasing southerly wind fetch and building waves may
create a moderate risk for the development of dangerous rip
currents on Monday along parts of the New Jersey and Delaware
coastlines.

&&

.CLIMATE...
Record Temperatures for today:

7/21
Site     Max/Year          High Min/Year
ABE      101/1980             75/1980
ACY       99/1981             77/1991
PHL      103/1930             79/2017
ILG      102/1957             77/1972
RDG      102/2011             77/2011
TTN      101/1930             78/1980
MPO       94/2011             72/2011
GED      101/1957             79/2017

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Excessive Heat Warning until 10 PM EDT this evening for PAZ054-
     055-060>062-070-071-101>106.
     Flash Flood Watch from 8 AM EDT Monday through Tuesday morning
     for PAZ054-055-060>062-070-071-101>106.
NJ...Excessive Heat Warning until 10 PM EDT this evening for NJZ001-
     007>010-012>027.
     Flash Flood Watch from 8 AM EDT Monday through Tuesday morning
     for NJZ001-007>010-012>027.
     Heat Advisory until 7 PM EDT Monday for NJZ016-021-023-024.
DE...Excessive Heat Warning until 10 PM EDT this evening for
     DEZ001>004.
     Flash Flood Watch from 8 AM EDT Monday through Tuesday morning
     for DEZ001>004.
     Heat Advisory until 7 PM EDT Monday for DEZ001>004.
MD...Excessive Heat Warning until 10 PM EDT this evening for MDZ008-
     012-015-019-020.
     Flash Flood Watch from 8 AM EDT Monday through Tuesday morning
     for MDZ008-012-015-019-020.
     Heat Advisory until 7 PM EDT Monday for MDZ008-012-015-019-020.
MARINE...None.

&&

Synopsis...Fitzsimmons
Near Term...CMS/Johnson
Short Term...Johnson
Long Term...Fitzsimmons
Aviation...CMS/Fitzsimmons/Johnson
Marine...Fitzsimmons/Johnson
Climate...Staarmann
Hazardous weather outlook, Jul 21, 10:05 PM EDT, 37 minutes before
Hazardous Weather Outlook
National Weather Service Mount Holly NJ
1005 PM EDT Sun Jul 21 2019

NJZ001-007>010-012-013-015-017>020-022-027-PAZ054-055-060>062-070-
071-101>106-230215-
Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-Western Monmouth-
Mercer-Gloucester-Camden-Northwestern Burlington-Ocean-Atlantic-
Southeastern Burlington-Carbon-Monroe-Berks-Lehigh-Northampton-
Delaware-Philadelphia-Western Chester-Eastern Chester-
Western Montgomery-Eastern Montgomery-Upper Bucks-Lower Bucks-
1005 PM EDT Sun Jul 21 2019

...FLASH FLOOD WATCH IN EFFECT FROM 8 AM EDT MONDAY THROUGH TUESDAY
MORNING...

This Hazardous Weather Outlook is for central New Jersey, northern
New Jersey, northwest New Jersey, southern New Jersey, east central
Pennsylvania, northeast Pennsylvania and southeast Pennsylvania.

.DAY ONE...Tonight.

Isolated storms may produce heavy rain and localized flooding as well
as damaging winds.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flash Flood Watch.

Thunderstorms Monday afternoon and evening could produce severe
weather with damaging winds being the biggest threat.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

DEZ001>003-MDZ008-012-015-019-020-NJZ016-021-023-230215-
New Castle-Kent-Inland Sussex-Cecil-Kent MD-Queen Annes-Talbot-
Caroline-Salem-Cumberland-Cape May-
1005 PM EDT Sun Jul 21 2019

...HEAT ADVISORY IN EFFECT UNTIL 7 PM EDT MONDAY...
...FLASH FLOOD WATCH IN EFFECT FROM 8 AM EDT MONDAY THROUGH TUESDAY
MORNING...

This Hazardous Weather Outlook is for central Delaware, northern
Delaware, southern Delaware, northeast Maryland and southern New
Jersey.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Heat Advisory.

Isolated storms may produce heavy rain and localized flooding as well
as damaging winds.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Heat Advisory.
   Flash Flood Watch.

Thunderstorms Monday afternoon and evening could produce severe
weather with damaging winds being the biggest threat.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

NJZ014-025-026-230215-
Eastern Monmouth-Coastal Atlantic-Coastal Ocean-
1005 PM EDT Sun Jul 21 2019

...FLASH FLOOD WATCH IN EFFECT FROM 8 AM EDT MONDAY THROUGH TUESDAY
MORNING...

This Hazardous Weather Outlook is for central New Jersey and
southern New Jersey.

.DAY ONE...Tonight.

Isolated storms may produce heavy rain and localized flooding as well
as damaging winds.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flash Flood Watch.

There is a moderate risk for the formation of dangerous rip currents
on Monday.

Thunderstorms Monday afternoon and evening could produce severe
weather with damaging winds being the biggest threat.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

NJZ024-230215-
Atlantic Coastal Cape May-
1005 PM EDT Sun Jul 21 2019

...HEAT ADVISORY IN EFFECT UNTIL 7 PM EDT MONDAY...
...FLASH FLOOD WATCH IN EFFECT FROM 8 AM EDT MONDAY THROUGH TUESDAY
MORNING...

This Hazardous Weather Outlook is for southern New Jersey.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Heat Advisory.

Isolated storms may produce heavy rain and localized flooding as well
as damaging winds.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Heat Advisory.
   Flash Flood Watch.

Thunderstorms Monday afternoon and evening could produce severe
weather with damaging winds being the biggest threat.

There is a moderate risk for the formation of dangerous rip currents
on Monday.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

DEZ004-230215-
Delaware Beaches-
1005 PM EDT Sun Jul 21 2019

...HEAT ADVISORY IN EFFECT UNTIL 7 PM EDT MONDAY...
...FLASH FLOOD WATCH IN EFFECT FROM 8 AM EDT MONDAY THROUGH TUESDAY
MORNING...

This Hazardous Weather Outlook is for southern Delaware.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Heat Advisory.

Isolated storms may produce heavy rain and localized flooding as well
as damaging winds.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Heat Advisory.
   Flash Flood Watch.

Thunderstorms Monday afternoon and evening could produce severe
weather with damaging winds being the biggest threat.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

ANZ430-431-450>455-230215-
Delaware Bay waters north of East Point NJ to Slaughter Beach DE-
Delaware Bay waters south of East Point NJ to Slaughter Beach DE-
Coastal waters from Sandy Hook to Manasquan Inlet NJ out 20 nm-
Coastal waters from Manasquan Inlet to Little Egg Inlet NJ out 20 nm-
Coastal waters from Little Egg Inlet to Great Egg Inlet NJ out 20 nm-
Coastal waters from Great Egg Inlet to Cape May NJ out 20 nm-
Coastal waters from Cape May NJ to Cape Henlopen DE out 20 nm-
Coastal waters from Cape Henlopen to Fenwick Island DE out 20 nm-
1005 PM EDT Sun Jul 21 2019

This Hazardous Weather Outlook is for Atlantic coastal waters and
Delaware Bay Waters.

.DAY ONE...Tonight.

There is a low probability for widespread hazardous weather.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Thunderstorms from Monday afternoon into Tuesday morning may be
accompanied by wind gusts in excess of 35 knots.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

CMS

In the hours before

Local storm report, Jul 21, 10:22 PM EDT, 20 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1022 PM EDT SUN JUL 21 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1015 PM     TSTM WND GST     TREXLERTOWN             40.55N 75.59W
07/21/2019  E70 MPH          LEHIGH             PA   STORM CHASER

            CHASER ESTIMATES GUSTS UP TO 70MPH.

&&

JEO
Local storm report, Jul 21, 10:27 PM EDT, 15 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1027 PM EDT SUN JUL 21 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1022 PM     TSTM WND DMG     SCHNECKSVILLE           40.67N 75.61W
07/21/2019                   LEHIGH             PA   STORM CHASER

            MULTIPLE TRANSFORMERS EXPLODING WITH
            ESTIMATED GUSTS TO AT LEAST 60MPH.

&&

JEO
Local storm report, Jul 21, 10:29 PM EDT, 13 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1029 PM EDT SUN JUL 21 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1025 PM     TSTM WND DMG     TREXLERTOWN             40.55N 75.60W
07/21/2019                   LEHIGH             PA   STORM CHASER

            MULTIPLE TRANSFORMERS EXPLODING WITH
            ESTIMATED GUSTS TO AT LEAST 60MPH.

&&

JEO
Local storm report, Jul 21, 10:34 PM EDT, 8 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1034 PM EDT SUN JUL 21 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1030 PM     TSTM WND DMG     1 W SALISBURY TWP       40.59N 75.44W
07/21/2019                   LEHIGH             PA   FIRE DEPT/RESCUE

            DOWNED WIRES ON ELLSWORTH ST.

&&

JEO
Local storm report, Jul 21, 10:35 PM EDT, 7 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1035 PM EDT SUN JUL 21 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1030 PM     TSTM WND DMG     1 ENE SALISBURY TWP     40.59N 75.41W
07/21/2019                   LEHIGH             PA   FIRE DEPT/RESCUE

            DOWNED TREES AND WIRES ON CHURCH RD.

&&

JEO
Local storm report, Jul 21, 10:41 PM EDT, 1 minute before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1041 PM EDT SUN JUL 21 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1013 PM     TSTM WND DMG     TREXLERTOWN             40.55N 75.60W
07/21/2019                   LEHIGH             PA   PUBLIC

            MPING REPORT OF 3 INCH TREE LIMBS OR POWER
            POLES SNAPPED.

&&

JEO

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 8:25 PM EDTSpecial Weather StatementPHICarbon, Lehigh, Northampton50 min
Jul 21, 8:44 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh, Monroe, Northampton46 min
Jul 21, 9:24 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Lehigh, Northampton51 min
Jul 21, 9:30 PM EDTSevere Thunderstorm WarningPHIChester45 min
Jul 21, 9:58 PM EDTAreal Flood AdvisoryPHIBerks, Bucks, Lehigh, Montgomery, Northampton2 hr
Jul 21, 10:14 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Lehigh, Montgomery, Northampton46 min
Jul 21, 10:30 PM EDTFlash Flood WarningPHIBerks, Lehigh, Northampton3 hr
Jul 21, 10:31 PM EDTFlash Flood WarningPHIBerks, Lehigh, Northampton3 hr
Jul 21, 10:35 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh40 min
Jul 21, 10:54 PM EDTSevere Thunderstorm WarningPHIDelaware25 min
Jul 21, 10:58 PM EDTAreal Flood AdvisoryPHIBerks, Chester, Montgomery59 min
Jul 21, 11:05 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Lehigh, Montgomery40 min
Jul 21, 11:31 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia44 min
Jul 21, 11:38 PM EDTFlash Flood WarningPHIBerks, Carbon, Lehigh, Monroe, Northampton2 hr
Jul 21, 11:40 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Carbon, Lehigh, Montgomery, Northampton50 min
Jul 22, 12:05 AM EDTSevere Thunderstorm WarningPHICarbon, Monroe40 min
Jul 22, 12:45 AM EDTSpecial Weather StatementPHIMonroe30 min
Jul 22, 1:11 AM EDTSpecial Weather StatementPHIMonroe34 min
Jul 22, 5:32 AM EDTAreal Flood WarningPHILehigh49 min
Jul 22, 1:28 PM EDTSpecial Weather StatementPHIMonroe32 min
Jul 22, 1:50 PM EDTSpecial Weather StatementPHINorthampton25 min
Jul 22, 3:18 PM EDTSpecial Weather StatementPHIChester57 min
Jul 22, 3:27 PM EDTSevere Thunderstorm WarningPHIMonroe48 min
Jul 22, 3:33 PM EDTAreal Flood AdvisoryPHICarbon, Monroe, Northampton7 hr
Jul 22, 3:39 PM EDTSpecial Weather StatementPHIBerks51 min
Jul 22, 3:47 PM EDTSevere Thunderstorm WarningPHIChester, Delaware58 min
Jul 22, 4:11 PM EDTAreal Flood AdvisoryPHIBerks, Bucks, Chester, Lehigh, Montgomery, Northampton4 hr
Jul 22, 4:16 PM EDTSevere Thunderstorm WarningPHIChester, Delaware59 min
Jul 22, 4:40 PM EDTAreal Flood AdvisoryPHIDelaware, Montgomery, Philadelphia114 min
Jul 22, 4:55 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Lehigh, Montgomery, Northampton50 min
Jul 22, 5:04 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia41 min
Jul 22, 5:05 PM EDTFlash Flood WarningPHIBerks, Lehigh, Northampton4 hr
Jul 22, 5:14 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia61 min
Jul 22, 5:17 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Lehigh, Montgomery, Northampton73 min
Jul 22, 5:34 PM EDTFlash Flood WarningPHIBucks, Lehigh, Montgomery, Northampton4 hr
Jul 22, 5:40 PM EDTSevere Thunderstorm WarningPHIBucks, Philadelphia80 min
Jul 22, 5:43 PM EDTAreal Flood AdvisoryPHIBucks3 hr
Jul 22, 5:50 PM EDTSevere Thunderstorm WarningPHIBucks40 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2019Every severe thunderstorm warning in 2019

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.