Several weak disturbances and their associated boundaries, in combination with an unstable airmass, produced strong to severe thunderstorms over Delaware during the late afternoon and evening hours. Localized heavy downpours were also reported.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS PHI wrote it up.
Several weak disturbances and their associated boundaries, in combination with an unstable airmass, produced strong to severe thunderstorms over Delaware during the late afternoon and evening hours. Localized heavy downpours were also reported.
The local office's own words before the first event, 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 the first event at Jun 4, 8:58 PM EST, 12 minutes earlier.
Area Forecast Discussion
National Weather Service Mount Holly NJ
958 PM EDT Thu Jun 4 2020
.SYNOPSIS...
Unsettled weather will continue through the next several days
as multiple upper level disturbances move across the area,
before a cold front moves across the Mid Atlantic region
Saturday. High pressure will build across the northeast and Mid
Atlantic regions Late Sunday through at least Tuesday. Unsettled
weather may return toward the end of the week next week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
945 PM Update...As of mid evening, one area of storms
congealing into a N-S oriented line and closing in on SE PA and
Delmarva. Still upwards of 500-1000 j/kg of ML CAPE here so
still at least some potential for storms to be strong to severe
but we don't expect this to match the high end severe weather we
saw Wednesday. Additional showers/storms were located farther
north as of the mid evening across parts of the Lehigh Valley
into the southern Poconos. Instability is lower here so don't
see much of a severe threat but given that these are tending to
train, this will have to be monitored for hydro issues over the
next several hours. Biggest threat would be small stream
flooding and flooding of lower lying flood prone areas.
Showers/storms look to wind down overnight.
Previous Discussion: Fairly tricky forecast tonight, with the
convective evolution the obvious challenge. Storms are
developing rapidly this afternoon in central Pennsylvania south-
southwestward through southwest Virginia and adjacent West
Virginia. Several low- amplitude perturbations are moving east-
northeast across the Northeast/Mid-Atlantic. With strong
differential diabatic heating and orographic effects, sub-
synoptic lift has proven sufficient for convective initiation a
little bit earlier than most high-resolution guidance has been
depicting today. Meanwhile, a convectively-enhanced perturbation
moving through the upper Ohio Valley has generated vigorous and
well-organized convection in Ohio.
Unfortunately, high-resolution convection-allowing guidance has been
quite variable with the evolution of these two initially separate
regions of convection during the past day or so. However, there has
been some approach to convergence with the 12z/subsequent
simulations. In general, (1) the MCS in Ohio is expected to track
into central Pennsylvania and weaken in the higher terrain with the
loss of daytime heating, (2) another MCS may develop from the
convection in western Virginia and attempt to reach Delmarva after
sunset (though models are trending away from this, in general), and
(3) fairly disorganized/pulse-like convection in central
Pennsylvania and adjacent portions of Maryland/Virginia is progged
to congeal into a band or bands of convection in eastern
Pennsylvania and northern/central New Jersey (perhaps aided by
outflow from the upstream MCS). An examination of upper-air analyses
and satellite data would suggest that the stronger large-scale lift
will remain north of the Maryland border. With this in mind, have
trended PoPs higher to the north for late evening through the
overnight hours, with the highest PoPs between 00z and 06z. However,
concerned that convection will move in faster via recent radar
trends, so we may make some fairly quick adjustments as needed.
The severe-weather parameter space is sufficient for severe storms
(MUCAPE > 1000 J/kg; deep-layer vertical shear of 30-40 kt), though
low-level stability will increase via gradual nocturnal cooling. The
threat for heavy rainfall remains too, although think storm motions
are sufficiently high to preclude a larger threat of flash flooding.
In other words, I think the threat of severe storms is higher than
the threat of flash flooding.
Once the convection wanes (hopefully) after midnight, potential for
some localized fog may occur (similar to last night). However, left
this out of the forecast for now, as convection-allowing models have
hinted at potential for lingering showers/isolated storms
(especially recent HRRR simulations). Given the large uncertainty
with the precipitation forecast, did not want to provide too much
specificity to the grids afterward (at this point).
Lows tonight will be quite warm, with most readings in the 60s to
around 70.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
Concern is increasing tomorrow for another round of severe storms,
and heavy rainfall is also quite possible.
A stronger perturbation is expected to move into the Northeast by
Friday afternoon, with a surface trough attendant to this
perturbation moving into western portions of the CWA by afternoon.
Large-scale lift in advance of the trough combined with mesoscale
lift via the aforementioned trough, differential heating, and
orographic effects should readily generate convection by early
afternoon. The problem is that the orientation of the trough will be
increasingly parallel to the midlevel flow. The question will be how
parallel, as this will have implications on the progression of the
convection (e.g., the 12z GFS implies less parallel orientation and
quicker progression of the convection as a result; the 12z NAM is
slower and suggests very heavy rainfall possible in advance of the
slowly moving trough). Current thinking is that the slower
advancement of the trough is likely, especially on the northeast
side of the trough (where there is increased consensus for a more
west-to-east orientation of the boundary). Should this slower
progression materialize, some areas of the CWA will likely receive
high rainfall totals (2+ inches probable; 3+ inches possible). For
now, confidence is too low for a flash flood watch (particularly
given uncertainty with antecedent convection), but not ruling out
the possibility with future forecast updates.
Meanwhile, the severe-weather parameter space also remains favorable
for severe storms, with SBCAPE 1500-2000+ J/kg and deep-layer shear
of 25-35 kt possible by afternoon. Threat for wet microbursts
exists, with a more organized wind threat possible should a stronger
cold pool develop. Timing appears to be generally after midday and
mostly northwest of the urban corridor until the early evening, with
a slow progression east/southeast during the evening/overnight
hours. Threat for severe weather will likely peak in the late
afternoon/early evening, with the heavy rainfall threat possibly
existing longer in time thereafter.
Temperatures on Friday and Friday night will remain quite warm, with
mid 80s to low 90s for highs and upper 60s to low 70s for lows.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
After several days of active weather, including the beginning
of the long term period, quiet conditions return for much of the
rest of the extended period through the middle of next week,
before more potential unsettle weather returns by the end of the
week.
The beginning of the long term starts off with one final round
of showers and thunderstorms as a cold front will finally move
across the area. CAPE values build to 1000-2000 J/kg, while
shear is forecast to be 35-40 knots due to 700-500 mph winds of
30-40 knots. There will be some enhanced lift due to the front,
although not much significant short wave/vorticity impulses are
expected. However, with PWs increasing to 1.5-1.75 inches, any
showers or thunderstorms that do develop could contain a brief
period of moderate to heavy rainfall.
Behind the cold front, quiet conditions return to the area
beginning Sunday and continuing through the first half of next
week as high pressure builds across the northeast states and Mid
Atlantic region. For Sunday, the main concern will be the
potential for winds to gust around 15-20 mph, but winds for
Monday and Tuesday will be much weaker. Temperatures Sunday and
Monday return close to normal, before returning above normal on
Tuesday.
The high begins to get squeezed by Tuesday night into Wednesday
as a cold front approaches from the west, and an area of low
pressure approaches the east coast from the western Atlantic.
As we go into Thursday, the GFS and ECMWF begin to differ with
their outcomes. The GFS hangs the front to our west and keeps
the low offshore, while the ECMWF brings the front across the
eastern seaboard, before bringing the weak low across the area.
The ECMWF has a better chance of showers than the GFS, so we
will keep a chance of showers from late Wednesday into Thursday.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Tonight...Showers/storms look to affect most of the I-95
corridor sites and points north through late this evening
bringing temporary restrictions to IFR. After storms progress
east and/or dissipate overnight, local fog and/or lingering low
cloudiness may develop with additional periods of MVFR or even
IFR possible. Light south to southwest winds becoming light and
variable (outside of convection). Low confidence, particularly
after 06z.
Friday...Any lingering (local) fog and/or low clouds in the morning
becoming VFR quickly. However, storms are expected to develop
northwest of the urban corridor during the afternoon (including
RDG/ABE; generally after 18z), possibly affecting the Philly
terminals by 00z. Restrictions likely in proximity to storms. South
to southwest winds 5 to 15 kt. Strong/erratic gusts and torrential
downpours likely with the stronger storms. Moderate confidence.
Friday night...Storms with local restrictions likely, especially in
the evening. Residual restrictions late in the overnight possible.
Southwest winds up to 10 kt. Low confidence.
Outlook...
Saturday...Mostly VFR conditions expected. A chance of showers
and thunderstorms, which may temporarily lead to lower
conditions. West winds become northwest during the afternoon
with gusts 15-20 knots.
Saturday night-Tuesday...VFR conditions are expected through
the period.
&&
.MARINE...
South to southwest winds 10 to 20 kt are expected tonight through
Friday night, with seas generally below 5 feet. Cannot rule out a
marginal advisory gust or a period of seas around 5 feet, but
conditions are expected to remain predominantly sub-advisory.
A chance of storms exists tonight and again tomorrow evening/night.
Strong/erratic gusts, locally higher waves, and torrential downpours
are expected with the strongest storms.
OUTLOOK...
Saturday...Conditions expected to remain below advisory levels.
However, there will be a chance of showers and thunderstorms
Saturday afternoon which may contain gusty winds.
Saturday night-Tuesday...Conditions expected to remain below
advisory levels through the period, but winds may gust around 20
knots at times Saturday night through Sunday night.
&&
.TIDES/COASTAL FLOODING...
The astronomical tides associated with this full moon are
particularly high, especially the high tide this evening and
tonight. Only a modest positive tidal departure will result in
minor flooding this evening.
Tidal departure this evening will range from +0.5 to +1.0, and
this will be enough to produce minor coastal flooding along the
New Jersey and Delaware oceanfront, many of the Atlantic bays,
as well as Delaware Bay, and up the Delaware River.
South to southeast flow will result in a buildup of water that
will continue into tonight. As a result, went ahead and expanded
the Coastal Flood Advisory to include all coastal areas
tonight.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Coastal Flood Advisory until 5 AM EDT Friday for PAZ070-071-
106.
NJ...Coastal Flood Advisory until midnight EDT tonight for
NJZ012>014-020>027.
Coastal Flood Advisory until 5 AM EDT Friday for NJZ015-
017>019.
Coastal Flood Advisory until 1 AM EDT Friday for NJZ016.
DE...Coastal Flood Advisory until midnight EDT tonight for
DEZ002>004.
Coastal Flood Advisory until 1 AM EDT Friday for DEZ001.
MD...None.
MARINE...None.
&&
Synopsis...Robertson
Near Term...CMS/Fitzsimmons
Short Term...CMS
Long Term...Robertson
Aviation...CMS/Fitzsimmons/Robertson
Marine...CMS/Robertson
Tides/Coastal Flooding...Hazardous Weather Outlook National Weather Service Mount Holly NJ 438 PM EDT Thu Jun 4 2020 NJZ001-007>010-PAZ054-055-062-052045- Sussex-Warren-Morris-Hunterdon-Somerset-Carbon-Monroe-Northampton- 438 PM EDT Thu Jun 4 2020 This Hazardous Weather Outlook is for northern New Jersey, northwest New Jersey, east central Pennsylvania and northeast Pennsylvania. .DAY ONE...Tonight. There is a low probability for widespread hazardous weather. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Thunderstorms are expected to develop on Friday afternoon. Some may produce locally heavy rainfall, with instances of flash flooding possible. Damaging wind gusts may also occur with the strongest storms. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. NJZ015-052045- Mercer- 438 PM EDT Thu Jun 4 2020 ...COASTAL FLOOD ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 5 AM EDT FRIDAY... This Hazardous Weather Outlook is for central 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. Coastal Flood Advisory. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Thunderstorms are expected to develop on Friday afternoon. Some may produce locally heavy rainfall, with instances of flash flooding possible. Damaging wind gusts may also occur with the strongest storms. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. NJZ012-013-052045- Middlesex-Western Monmouth- 438 PM EDT Thu Jun 4 2020 ...COASTAL FLOOD ADVISORY IN EFFECT UNTIL MIDNIGHT EDT TONIGHT... This Hazardous Weather Outlook is for central New Jersey and northern 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. Coastal Flood Advisory. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Thunderstorms are expected to develop on Friday afternoon. Some may produce locally heavy rainfall, with instances of flash flooding possible. Damaging wind gusts may also occur with the strongest storms. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. MDZ008-012-015-019-020-PAZ060-061-101>105-052045- Cecil-Kent MD-Queen Annes-Talbot-Caroline-Berks-Lehigh- Western Chester-Eastern Chester-Western Montgomery- Eastern Montgomery-Upper Bucks- 438 PM EDT Thu Jun 4 2020 This Hazardous Weather Outlook is for northeast Maryland, east central Pennsylvania and southeast Pennsylvania. .DAY ONE...Tonight. Showers and thunderstorms this evening may bring strong wind gusts, hail and heavy rain. The rain could result in localized flooding of small streams and areas of poor drainage. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Thunderstorms are expected to develop on Friday afternoon. Some may produce locally heavy rainfall, with instances of flash flooding possible. Damaging wind gusts may also occur with the strongest storms. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. NJZ017>019-PAZ070-071-106-052045- Gloucester-Camden-Northwestern Burlington-Delaware-Philadelphia- Lower Bucks- 438 PM EDT Thu Jun 4 2020 ...COASTAL FLOOD ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 5 AM EDT FRIDAY... This Hazardous Weather Outlook is for southern New Jersey and southeast Pennsylvania. .DAY ONE...Tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Coastal Flood Advisory. Showers and thunderstorms this evening may bring strong wind gusts, hail and heavy rain. The rain could result in localized flooding of small streams and areas of poor drainage. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Thunderstorms are expected to develop on Friday afternoon. Some may produce locally heavy rainfall, with instances of flash flooding possible. Damaging wind gusts may also occur with the strongest storms. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. DEZ001-NJZ016-052045- New Castle-Salem- 438 PM EDT Thu Jun 4 2020 ...COASTAL FLOOD ADVISORY IN EFFECT FROM 9 PM THIS EVENING TO 1 AM EDT FRIDAY... This Hazardous Weather Outlook is for northern Delaware 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. Coastal Flood Advisory. Showers and thunderstorms this evening may bring strong wind gusts, hail and heavy rain. The rain could result in localized flooding of small streams and areas of poor drainage. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Thunderstorms are expected to develop on Friday afternoon. Some may produce locally heavy rainfall, with instances of flash flooding possible. Damaging wind gusts may also occur with the strongest storms. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. DEZ002-003-NJZ020>023-027-052045- Kent-Inland Sussex-Ocean-Cumberland-Atlantic-Cape May- Southeastern Burlington- 438 PM EDT Thu Jun 4 2020 ...COASTAL FLOOD ADVISORY IN EFFECT UNTIL MIDNIGHT EDT TONIGHT... This Hazardous Weather Outlook is for central Delaware, southern Delaware 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. Coastal Flood Advisory. Showers and thunderstorms this evening may bring strong wind gusts, hail and heavy rain. The rain could result in localized flooding of small streams and areas of poor drainage. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. There is a low probability for widespread hazardous weather. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. NJZ014-052045- Eastern Monmouth- 438 PM EDT Thu Jun 4 2020 ...COASTAL FLOOD ADVISORY IN EFFECT UNTIL MIDNIGHT EDT TONIGHT... This Hazardous Weather Outlook is for central 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. Coastal Flood Advisory. There is a moderate risk for the development of dangerous rip currents. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. There is a moderate risk for the development of dangerous rip currents on Friday. Thunderstorms are expected to develop on Friday afternoon. Some may produce locally heavy rainfall, with instances of flash flooding possible. Damaging wind gusts may also occur with the strongest storms. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. NJZ024>026-052045- Atlantic Coastal Cape May-Coastal Atlantic-Coastal Ocean- 438 PM EDT Thu Jun 4 2020 ...COASTAL FLOOD ADVISORY IN EFFECT UNTIL MIDNIGHT EDT TONIGHT... 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. Coastal Flood Advisory. There is a moderate risk for the development of dangerous rip currents. Showers and thunderstorms this evening may bring strong wind gusts, hail and heavy rain. The rain could result in localized flooding in areas of poor drainage. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. There is a moderate risk for the development of dangerous rip currents on Friday. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. DEZ004-052045- Delaware Beaches- 438 PM EDT Thu Jun 4 2020 ...COASTAL FLOOD ADVISORY IN EFFECT UNTIL MIDNIGHT EDT TONIGHT... 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. Coastal Flood Advisory. Showers and thunderstorms this evening may bring strong wind gusts, hail and heavy rain. The rain could result in localized flooding in areas of poor drainage. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. There is a low probability for widespread hazardous weather. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. ANZ450-052045- Coastal waters from Sandy Hook to Manasquan Inlet NJ out 20 nm- 438 PM EDT Thu Jun 4 2020 This Hazardous Weather Outlook is for Atlantic coastal waters. .DAY ONE...Tonight. There is a low probability for widespread hazardous weather. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Storms may produce strong wind gusts and locally higher waves late Friday afternoon into Friday night. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to standard operating procedures. ANZ430-431-451>455-052045- 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 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- 438 PM EDT Thu Jun 4 2020 This Hazardous Weather Outlook is for Atlantic coastal waters and Delaware Bay Waters. .DAY ONE...Tonight. Showers and thunderstorms this evening may bring strong wind gusts, and hail. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Storms may produce strong wind gusts and locally higher waves late Friday afternoon into Friday night. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to standard operating procedures. CMS
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
714 PM EDT THU JUN 4 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0700 PM TSTM WND GST 1 SSW RUSCOMBMANOR TWP 40.41N 75.83W
06/04/2020 M58 MPH BERKS PA PUBLIC
CWOP SITE.
&&
JEOPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
744 PM EDT THU JUN 4 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0630 PM TSTM WND DMG BERNVILLE 40.43N 76.11W
06/04/2020 BERKS PA 911 CALL CENTER
A FEW TREES REPORTED DOWN IN BERNVILLE. ALSO
A COUPLE OF SPORADIC DOWNED TREE REPORTS IN
NEARBY AREAS. TIME ESTIMATED FROM RADAR.
&&
JEOSpecial Weather Statement
National Weather Service Mount Holly NJ
747 PM EDT Thu Jun 4 2020
NJZ009-PAZ061-062-105-050030-
Hunterdon-Upper Bucks-Lehigh-Northampton-
747 PM EDT Thu Jun 4 2020
...A STRONG THUNDERSTORM WILL AFFECT SOUTHWESTERN HUNTERDON...
SOUTHEASTERN LEHIGH...NORTHWESTERN BUCKS AND SOUTH CENTRAL
NORTHAMPTON COUNTIES...
At 746 PM EDT, a strong thunderstorm was located over Quakertown, or
10 miles southeast of Allentown, moving east at 25 mph.
Wind gusts up to 40 mph are possible with this storm.
Locations impacted include...
Allentown, Bethlehem, Emmaus, Quakertown, Byram, Bedminster,
Hellertown, Tinicum, Ferndale, Frenchtown, Milford, Bloomsbury,
Riegelsville, Stockton, Pleasant Valley, Revere, Lumberville,
Ottsville, Geryville and Pipersville.
This includes the following highways...
Interstate 78 in Pennsylvania between mile markers 57 and 70.
Northeast Extension near exit A44.
Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
LAT...LON 4057 7552 4063 7519 4061 7520 4059 7518
4063 7515 4065 7510 4066 7504 4041 7495
4039 7544 4041 7548
TIME...MOT...LOC 2346Z 259DEG 22KT 4046 7539
GorseSpecial Weather Statement
National Weather Service Mount Holly NJ
915 PM EDT Thu Jun 4 2020
MDZ008-012-015-019-050200-
Queen Anne's-Talbot-Cecil-Kent-
915 PM EDT Thu Jun 4 2020
...A LINE OF STRONG THUNDERSTORMS WILL AFFECT TALBOT...QUEEN
ANNE'S...KENT AND CENTRAL CECIL COUNTIES...
At 914 PM EDT, radar indicated strong thunderstorms were located
along a line extending from near White Marsh to near Magothy River to
near Dunkirk. Movement was east at 40 mph.
Wind gusts up to 50 mph and pea size hail are possible with these
storms.
Locations impacted include...
Easton, Elkton, Centerville, Talbot, Chestertown, Centreville, North
East, Romancoke, Rock Hall, Charlestown, St. Michaels, Church Hill,
Cecilton, Oxford, Sudlersville, Queen Anne, Old Town, Grasonville,
Starr and Copperville.
This includes Interstate 95 in Maryland between mile markers 92 and
105.
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with these storms, and may
cause localized flooding. Do not drive your vehicle through flooded
roadways.
LAT...LON 3886 7626 3886 7625 3879 7620 3879 7619
3894 7621 3884 7637 3885 7638 3894 7636
3897 7635 3904 7631 3900 7617 3917 7628
3943 7600 3958 7610 3968 7585 3917 7585
3869 7605 3867 7620 3878 7629 3867 7634
TIME...MOT...LOC 0114Z 248DEG 35KT 3939 7638 3901 7638 3868 7662
MPSSpecial Weather Statement
National Weather Service Mount Holly NJ
954 PM EDT Thu Jun 4 2020
DEZ001-002-MDZ008-012-015-019-020-NJZ016-PAZ102-050230-
Kent-New Castle-Queen Anne's-Talbot-Cecil-Kent-Caroline-Salem-Eastern
Chester-
954 PM EDT Thu Jun 4 2020
...A LINE OF STRONG THUNDERSTORMS WILL AFFECT NEW CASTLE...WESTERN
KENT...TALBOT...EASTERN QUEEN ANNE'S...CAROLINE...NORTHEASTERN
KENT...EASTERN CECIL...WESTERN SALEM AND SOUTH CENTRAL CHESTER
COUNTIES...
At 954 PM EDT, radar indicated strong thunderstorms were located
along a line extending from Fair Hill to near Crumpton to Oxford.
Movement was east at 45 mph.
Wind gusts up to 50 mph are possible with these storms.
Locations impacted include...
Wilmington, Dover, Newark, Middletown, Easton, Elkton, Pennsville,
Smyrna, Carneys Point, Elsmere, New Castle, Penns Grove, Salem,
Denton, North East, Camden, Clayton, Federalsburg, Greensboro and
Oakland.
This includes the following highways...
Interstate 295 in New Jersey between mile markers 0 and 3.
Interstate 95 in Maryland between mile markers 101 and 109.
Interstate 95 in Delaware between mile markers 0 and 21.
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with these storms, and may
cause localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
LAT...LON 3863 7608 3864 7615 3868 7617 3867 7620
3871 7624 3921 7595 3974 7595 3984 7551
3983 7546 3928 7544 3883 7568 3883 7572
3876 7572 3868 7576 3868 7580 3871 7584
3870 7590 3866 7596 3860 7599 3857 7604
TIME...MOT...LOC 0154Z 258DEG 40KT 3969 7588 3923 7588 3868 7620
MPSSpecial Weather Statement
National Weather Service Mount Holly NJ
1005 PM EDT Thu Jun 4 2020
DEZ001-PAZ060-070-071-101>104-050245-
New Castle-Eastern Montgomery-Western Montgomery-Delaware-Western
Chester-Eastern Chester-Berks-Philadelphia-
1005 PM EDT Thu Jun 4 2020
...A LINE OF STRONG THUNDERSTORMS WILL AFFECT NORTH CENTRAL NEW
CASTLE...SOUTHEASTERN BERKS...MONTGOMERY...CHESTER...PHILADELPHIA AND
DELAWARE COUNTIES...
At 1004 PM EDT, radar indicated strong thunderstorms were located
along a line extending from Terre Hill to near Coatesville to
Ladenberg. Movement was northeast at 60 mph.
Wind gusts up to 40 mph are possible with these storms.
Locations impacted include...
Philadelphia, West Chester, Norristown, Chester, Pottstown,
Phoenixville, Lansdale, West Norriton, East Norriton, Coatesville,
Yeadon, Westtown, Downingtown, Conshohocken, Hatboro, Souderton,
Folcroft, Ambler, Swarthmore and Kennett Square.
This includes the following highways...
Interstate 95 in Pennsylvania between mile markers 7 and 8, between
mile markers 13 and 14, and between mile markers 19 and 24.
Interstate 476 in Pennsylvania between mile markers 0 and 19.
Pennsylvania Turnpike between exits 298 and 343.
Northeast Extension between exits A20 and A31.
Interstate 176 in Pennsylvania between mile markers 1 and 3.
Interstate 676 in Pennsylvania between mile markers 0 and 1.
Interstate 76 in Pennsylvania between mile markers 327 and 351.
Torrential rainfall is also occurring with these storms, and may
cause localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
LAT...LON 4004 7593 4011 7594 4014 7588 4018 7594
4044 7552 4015 7506 3997 7511 3995 7514
3991 7513 3976 7583 3997 7590 4001 7595
TIME...MOT...LOC 0204Z 209DEG 51KT 4015 7604 4002 7587 3977 7579
GorseThe Dover AFB radar (KDOX), 41 km away, was scanning. The volume nearest the first event began at 02:08 UTC.
6 thunderstorm wind. Local standard time, as filed.
A few trees were downed in Marydel due to severe winds. Also some power outages in the area. Time estimated from radar.
Measured wind gust of 59 MPH.
Downed tree and wires near the intersection of main street and Middletown-Warwick Road. Time estimated from radar.
Large tree and power lines down. Time estimated from radar.
Downed utility pole on Ashland-Clinton School Road near Old Kennett Road. Time estimated from radar.
Downed tree and wires near Old Kennett Road and Way Road. Time estimated from radar.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Delaware in 2020Every state in 2020This day in weather historyWarnings in Delaware, June 2020
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 885072, 885078, 885073, 885074, 885076, 885077.