Pennsylvania, 2017

Hail and Damaging Winds in Pennsylvania, February 25, 2017

February 25, 2017 · NWS PHI · 28 events in 6 counties and zones

Several days of record warmth came to an end with a frontal passage. Abnormally high moisture and instability was present ahead of the front.

Where it happened

Every event with a place to put it. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

Open the live radar over this ground

The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
28

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.

What happened

The episode as NWS PHI wrote it up.

Several days of record warmth came to an end with a frontal passage. Abnormally high moisture and instability was present ahead of the front. This led to a line of showers and thunderstorms ahead of the front that produced damaging winds and hail during the late afternoon hours. Thousands of people lost power and the hardest hit regions were from Berks county northward into the Lehigh Valley. Philadelphia International had a ground stop during the storms with numerous flight delays.

What forecasters said that day

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 Feb 25, 2:54 PM EST, 26 minutes earlier.

Area forecast discussion, Feb 25, 2:54 PM EST, 26 minutes before
Area Forecast Discussion
National Weather Service Mount Holly NJ
254 PM EST Sat Feb 25 2017

.SYNOPSIS...
In the wake of the strong cold front moving through our region
Saturday afternoon, cooler air will settle in over the region. High
pressure then builds south of the region on Sunday before moving
offshore on Monday. Low pressure approaching from the west will lift
a warm front through the region on Tuesday. The aforementioned low
will propagate from the Great Lakes region into eastern Canada.
The associated cold front will move through Wednesday night or
Thursday. A quick moving low pressure system will slide over the
Mid Atlantic at the end of the week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
245 pm update: Forecast updated to include severe thunderstorm
watch 40 for portions of eastern PA and northern NJ until 9 pm.
Storms along a line from Oneonta, NY, to Pottsville, PA, have
rapidly intensified in the past hour. Damaging winds remain the
primary threat, but updrafts in environment of very strong shear
and marginally sufficient buoyancy appear to be capable of
producing hail approaching severe levels as well.

PoPs/weather grids/temperatures/winds updated through tonight to
account for latest trends. A more comprehensive near-term
discussion will be issued within the hour.

130 pm update: Forecast updated to include severe thunderstorm
watch 39 for portions of southeast PA, southwest NJ, the Eastern
Shore of MD, and northern/central DE until 8 pm. Grids updated
to include isolated damaging wind gusts.

Environment continues to become more favorable for severe
storms, with storms rapidly intensifying from Harrisburg, PA,
southwestward to Charlottesville, VA. These storms are moving
into an increasingly unstable air mass, with MLCAPE 500-1000
J/kg and effective bulk shear 40-60 kts. With continued heating
in the low levels, near-surface lapse rates are continuing to
increase, with 7-7.5 C/km readings reaching the I-76 corridor.
Though thermodynamic profiles do not appear favorable for large
hail, some subsevere hail is possible with the strongest
updrafts.

1230 pm update: Environment is becoming more unstable this
afternoon as diabatic heating has increased with the partial
clearing observed in much of the area this morning. Model
analyses indicate MLCAPE 500-1000 J/kg generally south of I-76
(and away from the coast) with effective bulk shear 40-60 kts.
Though low-level lapse rates have been slow to improve this
morning, some 7+ C/km readings are now present in southeast PA.
As the cold front nears the region this afternoon, scattered
storms should continue to intensify in the increasingly unstable
air downstream. Already have showers developing in the southern
Poconos, with a clear uptick in convection in central PA during
the past hour. With fast unidirectional flow oriented parallel
to the front, one or more lines of storms should quickly
organize as it/they move east into the area along/ahead of the
front. Downward momentum transfer of this fast flow remains
possible with the stronger updraft cores, at least in isolated
instances, especially if surface heating continues this
afternoon (improving low-level lapse rates).

Made substantial modifications to the forecast this afternoon.
Increased temps across the area a bit more, changed PoPs to
account for latest trends, and kept mention of fog in coastal
NJ, where southeast winds will likely keep patches/areas of fog
around before the storms move in.

930 am update: Boundary layer mixing has successfully eroded
most of the lower clouds and fog in far southeast PA and much
of inland NJ; however, patchy dense fog continues across coastal
NJ. Coastal webcams showing Seaside Heights shrouded in fog,
with at least patchy fog also visible near Atlantic City,
Belmar, Tom's River, and Cape May. Though improvement is
expected through the morning hours, nudged temperatures downward in
coastal areas just a touch through the day as the consistent
southeast fetch will likely advect cooler air over the ocean
waters inland and may keep low clouds in place through much of
the day.

Temperatures were running warmer than forecast in areas where
clouds have eroded, but suspect the warming trend will be brief
given the increasing clouds moving in from the west. Tweaked
hourly temperature grids to account for the current trends, but
only modified max temps a degree or two in most locations, as
the expected slowing trend of the warming will likely preclude
temperatures from exceeding guidance excessively, as has been
observed several times in the past week.

Regarding the convective potential this afternoon, not much has
changed with the forecast thinking. High-resolution guidance has
been quite consistent with the timing of the main line of
convection generally from 20Z to 01Z from west to east.
Instability continues to look marginal but sufficient for
updraft maintenance as the cold front approaches the region
this afternoon. Within an environment of favorable deep-layer
shear and unidirectional wind profiles with directions mostly
parallel to the front, a line of convection will likely progress
through the area. The line may contain little lightning given
the marginal/thin CAPE profile, but with steep low-level lapse
rates underneath fast midlevel flow, downward momentum transfer
of these strong winds should occur with relative ease during the
afternoon hours. With favorable low-level helicity in vicinity
of the front, bowing structures and even an embedded rotating
storm/mesovortex cannot be ruled out.

Previous discussion below...

Another rather mild early morning across the area. Several
items to discuss today as we have more warmth ahead of a strong
cold front. Some varying amounts of low clouds with patchy fog
this morning, with much of this (at least low clouds) across
portions of eastern Pennsylvania and northern New Jersey due to
more of an upslope component of the low-level flow. Some thicker
fog/stratus has been noted along portions of New Jersey coast
and near the far upper portion of Delaware Bay near Wilmington.
Some guidance keeps low clouds across much of the area all day,
however the thinking is that enough mixing and boundary layer
heating occurs to erode this by early afternoon. Some fog was
kept from northern Delaware eastward to the New Jersey coast.
We now switch to the convective potential with an incoming
strong cold front this afternoon.

A strong upper-level trough will continue to move from the
Midwest to across the Great Lakes region today. This trough is
forecast to start taking on a negative tilt as it reaches the
eastern Great Lakes later today. This will drive strong height
falls eastward this afternoon along with a strengthening wind
field. The forecast soundings indicate deep unidirectional flow
with some veering below about 900 mb. There should be enough
instability to produce some thunder this afternoon, however
strong forcing along the leading edge of the height falls along
with robust short wave energy should result in a convective
line. This line will probably be more low-topped, however
enough instability is expected inland to produce some lightning.

Given the deep unidirectional flow contributing to
strengthening shear, some bowing segments are possible within
the line. Momentum transfer of stronger winds from aloft down to
the surface can result in locally damaging gusts, especially
with any bowing segments along with stronger cores due to water
loading of the downdrafts. While some smaller hail cannot be
ruled out, instability should be limited as soundings show more
of a thin CAPE profile. We will continue to carry gusty winds in
the forecast with thunder (may need to add damaging winds
later), with the convective line generally moving from west to
east across the area from about 20-00z. The intensity of the
convection should lessen as it reaches the coast due to the
cooler ocean influence.

Southerly flow ahead of the cold front will result in another
very warm day, with several areas already starting rather warm.
Highs will be able to over achieve expectations if more clearing
occurs ahead of the cold front during peak heating. High
temperatures were a MOS/continuity blend but then raised some
away from the coast given a warmer start.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
A short term discussion will be included in the next update in
about an hour.

&&

.LONG TERM /SUNDAY THROUGH SATURDAY/...
Few changes made in the long term so as to focus on current hazards
this evening.

Unsettled weather pattern is on tap through the week.

Monday and Tuesday are very low confidence especially with respect
to precip chances. As long as the high isn't more progressive in
shifting off shore, during the day Monday should stay dry. Monday
night into Tuesday there is low confidence as to the extent of rain
ahead of the arrival of the warm front and with the timing of the
warm front. Models have continued their run-to-run jumpiness with
the timing of this front.

Wednesday and Wednesday night looks to be the highest chance of
precip with the region solidly in the warm sector. Thunderstorms may
be possible as well if we can warm up enough to realize some modest
surface based instability.

Cold front still on track to move through late Wedensday night or
Thursday. Once it moves through, we should see a lull in the precip,
albeit a brief one.

The next question will be the timing and track of a quick moving low
which could move across the region Friday or Friday night. Moisture
may be limited as there will be strong dry air advection behind the
cold front, but there is some chance for precip around the area.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

For the 18Z TAFs...Mostly VFR before storms move in this
afternoon. Timing looks to be 19-23Z for KRDG/KABE, 20-00Z for
KPHL/KPNE/KTTN/KILG, and 22-02Z for KMIV and KACY. Sub-VFR
VSBYs/CIGs expected as the precipitation moves through, with
gusty/erratic winds 30-45 kts possible in proximity to the stronger
storms. Winds will quickly veer to westerly or northwesterly
after shower/storm passage late this afternoon/evening, with
winds gusting 20-30 kts through tomorrow afternoon before
diminishing.

Outlook...
Sunday night and Monday...VFR conditions expected.

Monday night through Thursday...periods of rain and showers are
possible. When/if this does occur, MVFR ceilings or lower are
possible. Highest chance is Wednesday and Wednesday night. There is
considerable forecast uncertainty in this period.

&&

.MARINE...
1230 pm update: Dense fog continues to plague the waters off the
coast of New Jersey. Extended the dense fog advisory through 6
pm. Winds are slowly increasing over the waters as well, so
current SCA looks good.  Rest of forecast unchanged.

930 am update: Webcams continue to show dense fog over the
coastal waters of New Jersey. Expanded the dense fog advisory to
cover all marine zones adjacent to the coast through noon.
Otherwise, forecast is in good shape.

Previous discussion...

A narrow area of stratus and/or fog continues right near the
coast of New Jersey with this mostly confined from portions of
Ocean County northward. Farther south, the low-level trajectory
suggests less development however some fog has been reported.
The dense fog advisory this morning remains in effect for just the
northern two Atlantic coastal waters zones. Otherwise, a
southerly flow will continue today and the increase may be
slowed due to much warmer air over cooler water. This will
increase especially later today as a strong cold front arrives,
with colder air quickly arriving tonight in its wake. It is
tonight when stronger winds are expected as mixing becomes much
more efficient. There could be some low-end gale force gusts
tonight, however it looks marginal and potentially short in
duration therefore we will maintain the Small Craft Advisory.
Seas will also respond to the increasing wind, however this was
slowed a bit for this morning.

A line of showers and embedded thunderstorms will move across
the area late this afternoon and especially early this evening.
These may weaken some as they encounter the marine influence,
however some local gusts of 30-40 knots are possible along
portions of the line.

Outlook...
Sunday night and Monday...wind gusts to 25 kt may linger for a few
hours on Sunday evening, but will be below SCA criteria for the
remainder of this period.

Tuesday through Wednesday...winds and seas should generally stay
below SCA criteria, though wind gusts above 20kt will be possible on
Wednesday. Periods of rain/showers possible, especially on Wednesday.

Wednesday night and Thursday...Northwesterly wind gusts around 25 kt
are possible

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Dense Fog Advisory until 6 PM EST this evening for ANZ450>453.
     Small Craft Advisory until 6 PM EST Sunday for ANZ450>455.
     Small Craft Advisory from 6 PM this evening to 6 PM EST Sunday
     for ANZ430-431.

&&

Synopsis...Johnson
Near Term...CMS
Short Term...CMS
Long Term...Johnson
Aviation...CMS/Johnson
Marine...CMS/Johnson
Hazardous weather outlook, Feb 25, 2:55 PM EST, 25 minutes before
Hazardous Weather Outlook
National Weather Service Mount Holly NJ
255 PM EST Sat Feb 25 2017

DEZ001-002-MDZ008-012-015-019-020-NJZ016>018-021-PAZ060-070-071-
101>104-262000-
New Castle-Kent-Cecil-Kent MD-Queen Annes-Talbot-Caroline-Salem-
Gloucester-Camden-Cumberland-Berks-Delaware-Philadelphia-
Western Chester-Eastern Chester-Western Montgomery-
Eastern Montgomery-
255 PM EST Sat Feb 25 2017

...SEVERE THUNDERSTORM WATCH 39 IN EFFECT UNTIL 8 PM EST THIS
EVENING...

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

.DAY ONE...This Afternoon and Tonight.

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

   Severe Thunderstorm Watch.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
 conditions according to Standard Operating Procedures.

NJZ001-007>010-012-015-PAZ054-055-061-062-105-106-262000-
Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-Mercer-Carbon-
Monroe-Lehigh-Northampton-Upper Bucks-Lower Bucks-
255 PM EST Sat Feb 25 2017

...SEVERE THUNDERSTORM WATCH 40 IN EFFECT UNTIL 9 PM EST THIS
EVENING...

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

.DAY ONE...This Afternoon and Tonight.

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

   Severe Thunderstorm Watch.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
 conditions according to Standard Operating Procedures.

DEZ003-004-NJZ013-014-019-020-022>027-262000-
Inland Sussex-Delaware Beaches-Western Monmouth-Eastern Monmouth-
Northwestern Burlington-Ocean-Atlantic-Cape May-
Atlantic Coastal Cape May-Coastal Atlantic-Coastal Ocean-
Southeastern Burlington-
255 PM EST Sat Feb 25 2017

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

.DAY ONE...This Afternoon and Tonight.

Scattered strong to severe thunderstorms are possible through early
this evening. The primary hazard with these storms will be strong,
damaging winds.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
 conditions according to Standard Operating Procedures.

ANZ431-454-455-262000-
Delaware Bay waters south of East Point NJ to Slaughter Beach DE-
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-
255 PM EST Sat Feb 25 2017

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

.DAY ONE...This Afternoon and Tonight.

Scattered strong to severe thunderstorms are possible through this
evening. The primary hazard with these storms will be strong,
damaging winds.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
 conditions according to Standard Operating Procedures.

ANZ450>453-262000-
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-
255 PM EST Sat Feb 25 2017

...DENSE FOG ADVISORY IN EFFECT UNTIL 6 PM EST THIS EVENING...

This Hazardous Weather Outlook is for Atlantic coastal waters.

.DAY ONE...This Afternoon and Tonight.

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

   Dense Fog Advisory.

Scattered strong to severe thunderstorms are possible through this
evening. The primary hazard with these storms will be strong,
damaging winds.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
 conditions according to Standard Operating Procedures.

ANZ430-262000-
Delaware Bay waters north of East Point NJ to Slaughter Beach DE-
255 PM EST Sat Feb 25 2017

...SEVERE THUNDERSTORM WATCH 39 IN EFFECT UNTIL 8 PM EST THIS
EVENING...

This Hazardous Weather Outlook is for Delaware Bay Waters.

.DAY ONE...This Afternoon and Tonight.

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

   Severe Thunderstorm Watch.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
 conditions according to Standard Operating Procedures.

In the hours before

Special weather statement, Feb 25, 10:01 AM EST, 5 hours 19 minutes before
Special Weather Statement
National Weather Service Mount Holly NJ
1001 AM EST Sat Feb 25 2017

NJZ013-014-020-022>027-251715-
Western Monmouth-Eastern Monmouth-Ocean-Atlantic-Cape May-
Atlantic Coastal Cape May-Coastal Atlantic-Coastal Ocean-
Southeastern Burlington-
Including the cities of Freehold, Sandy Hook, Jackson, Hammonton,
Cape May Court House, Ocean City, Atlantic City,
Long Beach Island, and Wharton State Forest
1001 AM EST Sat Feb 25 2017

Patchy dense fog continues along the coast of New Jersey late this
morning. If traveling, be prepared for quick reductions in
visibility to less than a mile at times. Slow down, use low-beam
headlights, and keep extra distance between vehicles.

CMS
Special weather statement, Feb 25, 2:22 PM EST, 58 minutes before
Special Weather Statement
National Weather Service Mount Holly NJ
222 PM EST SAT FEB 25 2017

PAZ060-252015-
Berks-
222 PM EST SAT FEB 25 2017

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT WEST CENTRAL BERKS
COUNTY...

At 221 PM EST, radar indicated strong thunderstorms were located
along a line extending from near Bainbridge to Hallam. Movement was
northeast at 40 mph.

Wind gusts up to 50 mph are possible with these storms.

These storms will be near...
  Newmanstown around 305 PM EST.
  Womelsdorf, Wernersville and Robesonia around 310 PM EST.
  Bernville and Strausstown around 315 PM EST.

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.

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.

A severe thunderstorm watch remains in effect until 800 PM EST for
eastern Pennsylvania.

LAT...LON 4051 7639 4052 7634 4052 7625 4054 7617
      4035 7601 4028 7610 4036 7621 4037 7623
      4048 7641
TIME...MOT...LOC 1921Z 221DEG 37KT 4005 7663 4000 7662

wd
Special weather statement, Feb 25, 2:55 PM EST, 25 minutes before
Special Weather Statement
National Weather Service Mount Holly NJ
255 PM EST SAT FEB 25 2017

PAZ054-252045-
Carbon-
255 PM EST SAT FEB 25 2017

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT NORTHWESTERN CARBON
COUNTY...

At 254 PM EST, radar indicated strong thunderstorms were located
along a line extending from Olyphant to near Delano to Pottsville.
Movement was northeast at 45 mph.

Winds in excess of 40 mph and pea size hail are possible with these
storms.

Locations impacted include...
Weatherly, Beaver Meadows and Tresckow.

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.

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 4111 7567 4103 7575 4103 7576 4086 7594
      4091 7599 4098 7582 4104 7576 4109 7577
      4109 7576 4110 7575 4111 7572 4113 7569
      4113 7566
TIME...MOT...LOC 1954Z 214DEG 40KT 4146 7558 4087 7607 4066 7621

DRAG
Special weather statement, Feb 25, 3:02 PM EST, 18 minutes before
Special Weather Statement
National Weather Service Mount Holly NJ
302 PM EST SAT FEB 25 2017

MDZ008-PAZ060-101-102-252100-
Cecil-Western Chester-Eastern Chester-Berks-
302 PM EST SAT FEB 25 2017

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT NORTHWESTERN CECIL...
SOUTHEASTERN BERKS AND WESTERN CHESTER COUNTIES...

At 301 PM EST, radar indicated strong thunderstorms were located
along a line extending from near Manchester to near Jacobus to near
Hampstead. Movement was northeast at 50 mph.

Wind gusts up to 50 mph and half inch hail are possible with these
storms.

These storms will be near...
  Womelsdorf, Newmanstown and Robesonia around 340 PM EST.
  Wernersville around 345 PM EST.
  Fairview Hgts around 350 PM EST.
  Sinking Spring, Leesport and New Morgan around 355 PM EST.
  Reading, Coatesville, Wyomissing, Birdsboro, Laureldale,
  Parkesburg, Honey Brook and Spring Ridge around 400 PM EST.

Other locations impacted by these storms include Wyomissing Hills,
West Lawn, West Reading, Lorane, Kenhorst, Mount Penn, Reiffton,
Whitfield, St. Lawrence and West Wyomissing.

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.

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 3972 7614 3974 7612 3973 7610 3976 7606
      3983 7604 3987 7599 3995 7600 4004 7593
      4011 7594 4014 7588 4035 7620 4047 7596
      4037 7573 3979 7586 3969 7621 3972 7623
TIME...MOT...LOC 2001Z 234DEG 48KT 4008 7676 3985 7670 3958 7677

DRAG
Special weather statement, Feb 25, 3:05 PM EST, 15 minutes before
Special Weather Statement
National Weather Service Mount Holly NJ
305 PM EST SAT FEB 25 2017

MDZ008-012-015-019-PAZ101-102-252100-
Queen Anne's-Talbot-Cecil-Kent-Western Chester-Eastern Chester-
305 PM EST SAT FEB 25 2017

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT CENTRAL TALBOT...
CENTRAL QUEEN ANNE'S...KENT...WESTERN CECIL AND SOUTHWESTERN CHESTER
COUNTIES...

At 304 PM EST, radar indicated strong thunderstorms were located
along a line extending from near Manchester to near Nanjemoy Creek.
Movement was east at 40 mph.

Wind gusts up to 50 mph and half inch hail are possible with these
storms.

Locations impacted include...
Easton, Centerville, Calvert, Talbot, Chestertown, Centreville, North
East, Rising Sun, Rock Hall, Charlestown, St. Michaels, Oxford,
Betterton, Zion, Blake, Old Town, Grasonville, Copperville, Newtown
and West Nottingham.

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.

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.

A severe thunderstorm watch remains in effect until 800 PM EST for
eastern and northeastern Maryland...and southeastern Pennsylvania.

LAT...LON 3875 7635 3886 7626 3879 7620 3879 7619
      3894 7621 3889 7629 3896 7631 3884 7637
      3885 7638 3894 7636 3904 7631 3900 7617
      3917 7628 3952 7598 3972 7623 3980 7585
      3862 7612 3867 7634 3876 7638
TIME...MOT...LOC 2004Z 254DEG 37KT 3970 7682 3844 7712

Robertson

The radar

The Philadelphia radar (KDIX), 154 km away, was scanning. The volume nearest the first event began at 20:21 UTC.

Open the radar archive at this moment

Event by event

22 thunderstorm wind, 6 hail. Local standard time, as filed.

Hail, Berks

When
February 25, 3:20 PM EST
Where
Berks County, 0.53 mi E of Bernville
Measured
1 in hail
Reported by
Trained Spotter
Coordinates
40.430, -76.110

Quarter size hail was measured.

Hail, Berks

When
February 25, 3:45 PM EST
Where
Berks County, Stouchsburg
Measured
1 in hail
Reported by
Trained Spotter
Coordinates
40.380, -76.230

Quarter size hail was measured.

Thunderstorm Wind, Berks

When
February 25, 3:50 PM EST
Where
Berks County, 0.53 mi E of Montello
Measured
52 kt (60 mph) estimated gust
Reported by
Fire Department/Rescue
Coordinates
40.320, -76.020

Several trees snapped and uprooted due to thunderstorm winds.

Thunderstorm Wind, Berks

When
February 25, 3:50 PM EST
Where
Berks County, Sinking Spg
Measured
61 kt (70 mph) estimated gust
Reported by
Trained Spotter
Coordinates
40.330, -76.080

Five trees were downed and a part of a barn roof was torn off.

Hail, Berks

When
February 25, 3:54 PM EST
Where
Berks County, 0.53 mi E of Bernville
Measured
1 in hail
Reported by
Trained Spotter
Coordinates
40.430, -76.110

Quarter size hail was measured.

Thunderstorm Wind, Berks

When
February 25, 3:55 PM EST
Where
Berks County, 0.69 mi N of Hamburg
Measured
52 kt (60 mph) measured gust
Reported by
Trained Spotter
Coordinates
40.560, -75.980

A measured 60 mph gust.

Thunderstorm Wind, Berks

When
February 25, 3:56 PM EST
Where
Berks County, (Rdg)spaatz Fld Read
Measured
53 kt (61 mph) measured gust
Reported by
ASOS
Coordinates
40.380, -75.970

Measured 61 mph wind gust.

Thunderstorm Wind, Berks

When
February 25, 4:00 PM EST
Where
Berks County, 1.05 mi E of Reading
Measured
56 kt (64 mph) measured gust
Reported by
Mesonet
Coordinates
40.350, -75.900

Measured wind gust.

Thunderstorm Wind, Berks

When
February 25, 4:05 PM EST
Where
Berks County, 0.69 mi N of Fleetwood
Measured
61 kt (70 mph) estimated gust
Reported by
Broadcast Media
Coordinates
40.460, -75.820

Several power poles and trees were downed due to thunderstorm winds. A barn roof was blown off.

Thunderstorm Wind, Carbon

When
February 25, 4:06 PM EST
Where
Carbon County, Parryville
Measured
52 kt (60 mph) estimated gust
Reported by
State Official
Coordinates
40.820, -75.670

Trees down throughout the county particularly from Parryville and points northeast.

Thunderstorm Wind, Berks

When
February 25, 4:07 PM EST
Where
Berks County, Kutztown
Measured
61 kt (70 mph) estimated gust
Reported by
Social Media
Coordinates
40.520, -75.780

A roof of a medivac hanger was blown off and hit a house in a mobile home park due to thunderstorm winds. Power outages as well.

Thunderstorm Wind, Berks

When
February 25, 4:09 PM EST
Where
Berks County, 0.87 mi NW of Blandon
Measured
52 kt (60 mph) estimated gust
Reported by
Social Media
Coordinates
40.440, -75.890

Yard fencing was blown off due to thunderstorm winds.

Thunderstorm Wind, Lehigh

When
February 25, 4:11 PM EST
Where
Lehigh County, 0.52 mi E of Emerald
Measured
52 kt (60 mph) estimated gust
Reported by
State Official
Coordinates
40.750, -75.620

Several reports of downed power lines, poles and trees along with roof damage due to thunderstorm winds.

Hail, Berks

When
February 25, 4:15 PM EST
Where
Berks County, 0.53 mi W of Boyertown
Measured
0.75 in hail
Reported by
Trained Spotter
Coordinates
40.330, -75.640

Penny size hail was measured.

Thunderstorm Wind, Lehigh

When
February 25, 4:15 PM EST
Where
Lehigh County, 0.52 mi W of Slatington
Measured
52 kt (60 mph) estimated gust
Reported by
State Official
Coordinates
40.750, -75.610

Several reports of downed power lines and trees along with roof damage.

Thunderstorm Wind, Lehigh

When
February 25, 4:23 PM EST
Where
Lehigh County, Macungie
Measured
56 kt (64 mph) estimated gust
Reported by
State Official
Coordinates
40.520, -75.550

A roof was blown off an apartment building due to thunderstorm winds. All occupants were evacuated and had to seek housing elsewhere.

Thunderstorm Wind, Lehigh

When
February 25, 4:23 PM EST
Where
Lehigh County, Hynemansville
Measured
52 kt (60 mph) estimated gust
Reported by
State Official
Coordinates
40.600, -75.720

Several power poles downed due to thunderstorm winds.

Thunderstorm Wind, Lehigh

When
February 25, 4:25 PM EST
Where
Lehigh County, 1.38 mi N of Allentown Muni
Measured
52 kt (60 mph) estimated gust
Reported by
Newspaper
Coordinates
40.590, -75.480

Several trees downed in West Allentown due to thunderstorm winds.

Hail, Lehigh

When
February 25, 4:30 PM EST
Where
Lehigh County, 1.38 mi N of Allentown Muni
Measured
0.75 in hail
Reported by
Trained Spotter
Coordinates
40.590, -75.480

Penny size hail was measured.

Thunderstorm Wind, Northampton

When
February 25, 4:30 PM EST
Where
Northampton County, 0.52 mi W of Bushkill Center
Measured
61 kt (70 mph) estimated gust
Reported by
Trained Spotter
Coordinates
40.800, -75.310

Numerous trees, power lines and telephone poles down due to thunderstorm winds. Some of the trees were blown onto homes and a barn. A tractor trailer was also overturned due to the wind and moved 30 feet.

Thunderstorm Wind, Northampton

When
February 25, 4:30 PM EST
Where
Northampton County, 0.87 mi SE of Clearfield
Measured
52 kt (60 mph) estimated gust
Reported by
Trained Spotter
Coordinates
40.790, -75.340

A tree fell onto a barn, a horse died on Creamery road. Trees down on Keller Road, Gold Mill Road, Jacobsburg Drive, Parkland Drive and Renaldi Drive.

Thunderstorm Wind, Northampton

When
February 25, 4:31 PM EST
Where
Northampton County, 0.87 mi SE of Clearfield
Measured
52 kt (60 mph) estimated gust
Reported by
State Official
Coordinates
40.790, -75.340

Several trees and wires downed due to thunderstorm winds.

Thunderstorm Wind, Northampton

When
February 25, 4:35 PM EST
Where
Northampton County, 0.87 mi SW of Zucksville
Measured
52 kt (60 mph) estimated gust
Reported by
State Official
Coordinates
40.810, -75.260

Several trees and wires downed due to thunderstorm winds.

Thunderstorm Wind, Northampton

When
February 25, 4:35 PM EST
Where
Northampton County, 1.73 mi SW of Wind Gap
Measured
52 kt (60 mph) estimated gust
Reported by
Broadcast Media
Coordinates
40.830, -75.320

Several trees downed with one hitting a house on Sullivan trail.

Thunderstorm Wind, Northampton

When
February 25, 4:38 PM EST
Where
Northampton County, 0.52 mi E of Belfast
Measured
52 kt (60 mph) estimated gust
Reported by
Department of Highways
Coordinates
40.780, -75.270

Trees downed onto wires due to thunderstorm winds at Sullivan trail road between Belfast road and Church road.

Thunderstorm Wind, Northampton

When
February 25, 4:40 PM EST
Where
Northampton County, 1.25 mi WSW of Stockertown
Measured
52 kt (60 mph) estimated gust
Reported by
Newspaper
Coordinates
40.740, -75.270

Traffic lights were blown down at the Tatamy interchange on route 33.

Thunderstorm Wind, Delaware

When
February 25, 4:48 PM EST
Where
Delaware County, Markham
Measured
52 kt (60 mph) measured gust
Reported by
Trained Spotter
Coordinates
39.880, -75.520

Measured wind gust.

Hail, Philadelphia

When
February 25, 5:14 PM EST
Where
Philadelphia County, 1.06 mi E of Manayunk
Measured
0.75 in hail
Reported by
Trained Spotter
Coordinates
40.020, -75.210

Penny size hail was measured.

What these are

Hail
Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Thunderstorm Wind
Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Pennsylvania in 2017Every state in 2017This day in weather historyWarnings in Pennsylvania, February 2017

Sources

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: 671611, 671612, 671617, 671618, 671613, 671640, 671641, 671642, 671619, 671620, 671622, 671624, 671625, 671614, 671627, 671628, 671630, 671631, 671615, 671633, 671639, 671634, 671635, 671908, 671637, 671909, 671643, 671616.