This page was created to evaluate the precursor conditions to this unusual
MCS over land, and to describe
its effects across the eastern Great Lakes, Upper Ohio valley, and
northern Mid-Atlantic regions of the
United States.
All surface and upper level analyses shown below were performed
by members of the staff of the
Hydrometeorological Prediction Center (HPC) in Camp Springs, MD.
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An area of convection developed across eastern Iowa near a weak stationary/warm
front at 0302 GMT (image above),
and moved to the east along this old frontal boundary. By 1203
GMT (below), the convective system had matured,
taking on the shape of a wavy squall line across western Ohio and southern
Indiana.
At 250 hPa (below), the suspect area was in the right entrance
region of one upper jet streak, with a
stronger jet streak on its heels across the northern Plains, a very
favorable coupled jet structure. This led
to a significantly diffluent/divergent environment aloft, which allowed
the MCS to continue to evolve.
At 500 hPa (below), the trough is seen moving through the Ohio Valley, with its axis was still across Indiana.
At 850 hPa and in the precipitable water fields (below), you can see
the moisture pooling across Ohio
Valley, Pennsylvania, and New York, continuing the development of the
MCS.
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The surface analysis (below) shows the MCS as depicted with a trough
with a meso-high
quickly on its heels across southwest Ohio and southeast Indiana.
Due to the moisture present and daytime heating, thunderstorm activity
grew in coverage and
intensity across Kentucky at the tail of the outflow boundary, starving
the MCS of moisture and
causing it to weaken. Below is an image from 1503 GMT.
2. Formation of the eye feature
As the system moved away from the thunderstorm area over the Ohio Valley,
the system reintensified,
starting to form a large hook, with occasional hook echoes appearing
along its eastern side. This is also
the time when the cyclone became defined in the surface pressure and
wind patterns. Below is a radar
image from 1837 GMT, and the surface analysis from 1800 GMT.
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The system became more impressive later in the day. By 1900 GMT,
the central pressure of the cyclone
had fallen to 1001 hPa. Below is an image from 2036 GMT,
and the surface analysis from 2100 GMT.
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3. Death of the eye feature
By 2244 GMT, a squall line took shape along its band to the south.
This began to starve the inner
convection, which can be seen in the corresponding radar image from
that time.
By 0126 GMT, daytime heating had ceased, the squall line had run out
ahead of the low, causing
the entire convective structure to weaken (below).
4. Effects of the MCS
Rainfall was our main concern at the Hydrometeorological Prediction
Center. Below is
an isohyetal map of the rainfall observed at cooperative weather sites,
in inches.
Below is a list of post storm reports, reported by their respective
WFOs from Ohio to New York.
They speak for themselves.
| NWUS51 KCLE 220405
LSRCLE
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
0330 PM COCHRANTON
PA FLASH FLOODS
0330 PM COCHRANTON
PA FLASH FLOODS
0400 PM COCHRANTON
PA FLASH FLOODS
0400 PM TITUSVILLE
PA FLASH FLOODS
0400 PM LIITTLES CORNERS
PA FLASH FLOODS
MAT
NOUS41 KCLE 220347
PUBLIC INFORMATION STATEMENT
RAINFALL REPORTS SO FAR TODAY.
RAIN TIME/DATE
MEADVILLE 4.07 1000 PM 07/21 MANSFIELD AIRPORT 2.04 1124 PM 07/21 SAGERTOWN 4.00 1000 PM 07/21 CAMBRIDGE SPRINGS 4.00 1000 PM 07/21 TITUSVILLE 3.50 0600 PM 07/21 MEADVILLE AIRPORT 3.09 1120 PM 07/21 ERIE AIRPORT 1.14 1121 PM 07/21 AKRON CANTON AIRPORT 2.10 1121 PM 07/21
YOUNGSTOWN AIRPORT 4.66
1123 PM 07/21
CANTON NE WATER PLANT 0.80 1127 PM 07/21 CANTON NW WATER PLANT 1.20 1128 PM 07/21 WOOSTER WAYNE CO. AIRPORT 2.23 1128 PM 07/21 CLEVELAND LAKEFRONT 2.28 1140 PM 07/21 LORAIN COUNTY AIRPORT 1.31 1140 PM 07/21 RAVENNA 3.50 1145 PM 07/21 $$
THOMPSON
NWUS51 KCLE 220309
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
0145 PM YOUNGSTOWN
OH TORNADO
NWUS51 KCLE 220156
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
0200 PM SOUTHINGTON
OH FLASH FLOODS
0230 PM SAGERSTOWN
PA FLASH FLOODS
0310 PM TITUSVILLE
PA FLASH FLOODS
0125 PM LAKE MILTON
OH WIND DAMAGE
LINES DOWN.
0330 PM LINESVILLE
PA FLASH FLOODS
0733 PM LIBERTY
OH WIND DAMAGE
0740 PM HUDSON
OH FLASH FLOODS
0800 PM SILVER LAKE
OH FLASH FLOODS
0802 PM STOW
OH FLASH FLOODS
0833 PM WARREN
OH FLASH FLOODS
MAT
NWUS51 KILN 220118
PRELIMINARY LOCAL STORM REPORT...CORRECTION
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
0715 AM
IN WIND DAMAGE
0710 AM
IN WIND DAMAGE
0710 AM LIBERTY
IN WIND DAMAGE
0717 AM NULLTOWN
IN WIND DAMAGE
0725 AM
IN WIND DAMAGE
0718 AM 2 SW EATON
OH WIND DAMAGE 07/21/03
0733 AM
IN WIND DAMAGE 07/21/03
0900 AM ROCKFORD
OH FLOOD
0750 AM
IN WIND DAMAGE
0755 AM
IN WIND DAMAGE
0755 AM
OH WIND DAMAGE
0800 AM HARRISON
OH WIND DAMAGE
0810 AM
KY WIND DAMAGE
0802 AM S COVINGTON
KY 60 MPH TSTORM WIND ON
0815 AM NEW CARLISLE
OH WIND DAMAGE
0755 PM NW EATON
OH FLOOD
0751 PM RICHMOND
IN FLOOD
MG
NWUS51 KILN 220057
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
0715 AM RICHMOND
IN WIND DAMAGE
0710 AM BROOKVILLE
IN WIND DAMAGE
0710 AM LIBERTY
IN WIND DAMAGE
0717 AM NULLTOWN
IN WIND DAMAGE
0725 AM OSGOOD
IN WIND DAMAGE
0824 PM MANCHESTER
IN WIND DAMAGE
0825 PM ROCKFORD
OH FLOOD
0750 AM RISING SUN
IN WIND DAMAGE
0831 PM CENTER SQUARE
IN WIND DAMAGE
0755 AM HAMILTON
OH WIND DAMAGE
0833 PM HARRISON
OH WIND DAMAGE
0842 PM CALIFORNIA
KY WIND DAMAGE
0802 AM S COVINGTON
KY 60 MPH TSTORM WIND
0846 PM NEW CARLISLE
OH WIND DAMAGE
MG
NWUS51 KCLE 211906
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
0935 AM GALLION
OH WIND DAMAGE
0925 AM MOUNT GILEAD
OH WIND DAMAGE
0930 AM CHESTERVILLE
OH WIND DAMAGE
1005 AM 5 N ASHLAND
OH WIND DAMAGE
0930 AM CENTERBURG
OH 60 MPH TSTM WIND GUST
NWUS51 KCLE 211841
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
0615 AM WEST INDEPENDENCE
OH 1.00 INCH HAIL
LOMBARDY
NWUS51 KCLE 211825
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
0918 AM FINDLAY
OHIO WIND DAMAGE
0915 AM LARUE
OH WIND DAMAGE
1000 AM WASHINGTON TOWNSHIP
OH WIND DAMAGE
1240 PM FREEDOM
OH FLOOD
1255 PM FRANKLIN
OH FLOOD
1259 PM SILVER LAKE
OH FLOOD
0100 PM 5 NW WARREN
OH FLASH FLOODS
0117 PM 8 SW AKRON CANTON AIRPORT OH WIND
DAMAGE
0145 PM YOUNGSTOWN
OH WIND DAMAGE
LOMBARDY
NOUS41 KCTP 231908
...F1 TORNADO CONFIRMED IN LYCOMING COUNTY ON MONDAY JULY 21...
THE TORNADO FIRST TOUCHED DOWN ON FUNSTON ROAD IN LAIRDSVILLE WHERE
THE TORNADO PATH WAS 5 MILES LONG. THE TORNADO REACHED ONE HALF MILE
THE FUJITA SCALE RATES TORNADOES ON WIND SPEED AND DAMAGE. THE SCALE
F0...LESS THAN 73 MPH.
THE NATIONAL WEATHER SERVICE TEAM ALSO INVESTIGATED OTHER DAMAGE IN
IN LEWISBURG...THE DAMAGE WAS FAR MORE EXTENSIVE. HUNDREDS OF TREES
REMEMBER...THE BEST WAY TO STAY ON TOP OF WEATHER DEVELOPMENTS IN
$$
HEAD/ONDREJIK
PRELIMINARY LOCAL STORM REPORT
...REPORT ON TORNADO AND MACROBURST MONDAY AFTERNOON...
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
0225 PM 1 SW NEW LEBANON
PA TORNADO
0235 PM CARLTON
PA WIND DAMAGE
0245 PM OIL CITY
PA WIND DAMAGE
(SEE ALSO PITPNSPBZ FOR MORE DETAILS)
NOUS41 KPBZ 222334
PUBLIC INFORMATION STATEMENT
...DOWNBURST AND A TORNADO HIT PARTS OF WESTERN PENNSYLVANIA...
MANY COUNTIES ACROSS NORTHWEST PENNSYLVANIA EXPERIENCED EXTREMELY
IN MERCER COUNTY...PENNSYLVANIA
AN F0 TORNADO TOUCHED DOWN AROUND 225 PM TO THE NORTHEAST OF
MEANWHILE...FARTHER TO THE NORTHEAST IN MERCER COUNTY IN THE TOWN OF
IN VENANGO COUNTY...PENNSYLVANIA
THIS SAME INTENSE THUNDERSTORM SYSTEM PRODUCED A LARGE MACROBURST IN
IN ADDITION TO THE DAMAGE DESCRIBED ABOVE...THERE WERE SEVERAL AREAS
A DOWNBURST IS A STRONG WIND GUST ON OR NEAR THE GROUND WHICH IS
LAST YEAR IN THE COUNTY WARNING AREA OF THE NATIONAL WEATHER SERVICE
SO FAR THIS YEAR...TWO CONFIRMED TORNADOES HAVE OCCURRED ACROSS THE
KANE/GIGLIOTTI NOUS41 KCTP 222145
PUBLIC INFORMATION STATEMENT
...F3 TORNADO CONFIRMED IN POTTER COUNTY ON MONDAY JULY 21...
A TEAM FROM THE NATIONAL WEATHER SERVICE OFFICE IN STATE COLLEGE
THE TORNADO FIRST TOUCHED DOWN ABOUT 2 MILES SOUTHWEST OF THE TOWN
THE TORNADO PATH WAS 2 1/2 MILES LONG...WHILE THE WIDTH WAS ABOUT
THE FUJITA SCALE RATES TORNADOES ON WIND SPEED AND DAMAGE. THE SCALE
F0...LESS THAN 73 MPH.
REMEMBER...THE BEST WAY TO STAY ON TOP OF WEATHER DEVELOPMENTS IN
$$
JUNG/FOOSE
NOUS41 KCTP 222115 CCA
PUBLIC INFORMATION STATEMENT...CORRECTED FOR DATE
...STRAIGHT LINE WIND DAMAGE FOUND IN DAUPHIN COUNTY FROM JULY 21
A TEAM FROM THE NATIONAL WEATHER SERVICE OFFICE IN STATE COLLEGE
THE THUNDERSTORM PRODUCED WIND GUSTS OF 65 TO 70 MPH IN THE GREATER
$$
JUNG/BUDD
NOUS41 KCTP 222113 CCA
PUBLIC INFORMATION STATEMENT...CORRECTED FOR DATE
...F1 TORNADO CONFIRMED IN MCKEAN COUNTY ON MONDAY JULY 21...
A TEAM FROM THE NATIONAL WEATHER SERVICE OFFICE IN STATE COLLEGE
THE THUNDERSTORM WHICH SPAWNED THE TORNADO FIRST STARTED PRODUCING
THE TORNADO THEN LIFTED UP ABOUT 2 1/2 MILES NORTHEAST OF THE
THIS SECOND TOUCHDOWN DAMAGED 2 BARNS...AND DESTROYED A THIRD. TWO
THE FUJITA SCALE RATES TORNADOES ON WIND SPEED AND DAMAGE. THE SCALE
F0...LESS THAN 73 MPH.
REMEMBER...THE BEST WAY TO STAY ON TOP OF WEATHER DEVELOPMENTS IN
$$ JUNG/ONDREJIK NWUS51 KCTP 220400
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
0255 PM TROUTVILLE
PA POSSIBLE FUNNEL
0312 PM CURWENSVILLE
PA WIND DAMAGE
0330 PM ST MARYS
PA WIND DAMAGE
0345 PM KANE
PA WIND DAMAGE
0345 PM GREENCASTLE
PA WIND DAMAGE
0345 PM PETERSBURG
PA WIND DAMAGE
0415 PM WELLSBORO
PA WIND DAMAGE
0425 PM FLEMINGTON
PA WIND DAMAGE
0430 PM WATROUS
PA WIND DAMAGE
0430 PM LOCK HAVEN
PA WIND DAMAGE
0430 PM BEAVER SPRINGS
PA WIND DAMAGE
0430 PM REEDSVILLE
PA WIND DAMAGE
0433 PM GENESSE
PA TORNADO
0437 PM GALETON
PA WIND DAMAGE
0437 PM BRADFORD
PA FLOOD
0445 PM CURWENSVILLE
PA WIND DAMAGE
0446 PM GRANVILLE
PA WIND DAMAGE
0450 PM BRADFORD
PA WIND DAMAGE
0450 PM WALNUT
PA WIND DAMAGE
0500 PM MUNCY
PA WIND DAMAGE
0500 PM WILLIAMSPORT
PA WIND DAMAGE
0515 PM MILTON
PA WIND DAMAGE
0520 PM HUGHSVILLE
PA WIND DAMAGE
0530 PM HERNDON
PA WIND DAMAGE
0532 PM MILLERSTOWN
PA WIND DAMAGE
0555 PM WICONISCO
PA WIND DAMAGE
0600 PM MT. JEWETT
PA WIND DAMAGE
0600 PM MIFFLINBURG
PA WIND DAMAGE
0600 PM SUNBURY
PA WIND DAMAGE
0625 PM WATROUS
PA WIND DAMAGE
0625 PM YORK SPRINGS
PA WIND DAMAGE
0700 PM BLOOMSBURG
PA WIND DAMAGE
0730 PM DOVER
PA WIND DAMAGE
0753 PM SHIREMANSTOWN
PA WIND DAMAGE
0800 PM LANCASTER
PA 0.50 INCH HAIL
1000 PM KANE
PA FLOOD
1014 PM NEW COLUMBIA
PA WIND DAMAGE
1020 PM HARRISBURG
PA WIND DAMAGE
$$
NWUS51 KCTP 220336
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
0500 PM MUNCY
PA WIND DAMAGE
VGC
NWUS51 KPHI 220328
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
0655 PM JIM THORPE
PA WIND DAMAGE
0655 PM POCONO PINES
PA WIND DAMAGE
0715 PM BELTZVILLE
PA 0.25 IN HAIL
0725 PM TOBYHANNA
PA HEAVY RAIN
0735 PM DINGMANS FERRY
NJ WIND DAMAGE
0740 PM BLUE MOUNTAIN
PA WIND DAMAGE
0755 PM NW PART OF COUNTY
PA WIND DAMAGE
0755 PM NORTHERN 2/3RDS OF COUNTY PA WIND
DAMAGE
0810 PM WEST PART OF COUNTY
NJ WIND DAMAGE
0828 PM BLUE MOUNTAIN
PA WIND DAMAGE
0835 PM MOUNT PENN
PA 0.25 IN HAIL
0938 PM NORTHERN PART OF COUNTY PA
WIND DAMAGE
0940 PM BOYERTOWN
PA HEAVY RAIN
0940 PM POTTSTOWN
PA WIND DAMAGE
1000 PM POTTSTOWN
PA 0.25 IN HAIL
1000 PM SOUTH COVENTRY
PA HEAVY RAIN
NWUS51 KCTP 220320
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
0425 PM FLEMINGTON
PA WIND DAMAGE
0433 PM GENESSE
PA TORNADO
0532 PM MILLERSTOWN
PA WIND DAMAGE
1000 PM KANE
PA FLOOD
1014 PM NEW COLUMBIA
PA WIND DAMAGE
1020 PM HARRISBURG
PA WIND DAMAGE
VGC
NWUS51 KPBZ 220302
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
1050 PM EVANS CITY
PA WIND DAMAGE
NWUS51 KPBZ 220254
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
1050 PM SHARPSVILLE
PA FLASH FLOODS
NWUS51 KPHI 220211
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
0655 PM JIM THORPE
PA WIND DAMAGE
0655 PM POCONO PINES
PA WIND DAMAGE
0715 PM BELTZVILLE
PA 0.25 IN HAIL
0725 PM TOBYHANNA
PA HEAVY RAIN
0735 PM DINGMANS FERRY
NJ WIND DAMAGE
0740 PM BLUE MOUNTAIN
PA WIND DAMAGE
0755 PM NW PART OF COUNTY
PA WIND DAMAGE
0755 PM NORTHERN 2/3RDS OF COUNTY PA WIND
DAMAGE
0810 PM WEST PART OF COUNTY
NJ WIND DAMAGE
0828 PM BLUE MOUNTAIN
PA WIND DAMAGE
0835 PM MOUNT PENN
PA 0.25 IN HAIL
0940 PM BOYERTOWN
PA HEAVY RAIN
1000 PM POTTSTOWN
PA 0.25 IN HAIL
1000 PM SOUTH COVENTRY
PA HEAVY RAIN
NWUS51 KPBZ 220209
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
1000 PM FRANKLIN
PA FLASH FLOODS
0930 PM MERCER
PA FLASH FLOODS
0905 PM COUNTYWIDE
PA WIND DAMAGE
NWUS51 KCTP 220158
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
0345 PM PETERSBURG
PA WIND DAMAGE
0415 PM WELLSBORO
PA WIND DAMAGE
0415 PM WELLSBORO
PA WIND DAMAGE
0430 PM WATROUS
PA WIND DAMAGE
0530 PM HERNDON
PA WIND DAMAGE
0625 PM YORK SPRINGS
PA WIND DAMAGE
0700 PM BLOOMSBURG
PA WIND DAMAGE
0730 PM DOVER
PA WIND DAMAGE
0753 PM SHIREMANSTOWN
PA WIND DAMAGE
0800 PM LANCASTER
PA 0.50 INCH HAIL
NWUS51 KCTP 220153
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
0345 PM PETERSBURG BOROUGH
PA WIND DAMAGE
0415 PM WELLSBORO
PA WIND DAMAGE
0430 PM WATROUS
PA WIND DAMAGE
0530 PM HERNDON
PA WIND DAMAGE
0625 PM YORK SPRINGS
PA WIND DAMAGE
0700 PM BLOOMSBURG
PA WIND DAMAGE
0730 PM DOVER
PA WIND DAMAGE
0753 PM SHIREMANSTOWN
PA WIND DAMAGE
0800 PM LANCASTER
PA 0.50 INCH HAIL
$$
NWUS51 KCTP 212254 CCA
PRELIMINARY LOCAL STORM REPORT...CORRECTED LAST ENTRY
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
0255 PM TROUTVILLE
PA POSSIBLE FUNNEL
0312 PM CURWENSVILLE
PA WIND DAMAGE
0330 PM ST MARYS
PA WIND DAMAGE
0345 PM KANE
PA WIND DAMAGE
0345 PM GREENCASTLE
PA WIND DAMAGE
0345 PM PETERSBURG BOROUGH
PA WIND DAMAGE
0430 PM LOCK HAVEN
PA WIND DAMAGE
0430 PM BEAVER SPRINGS
PA WIND DAMAGE
0430 PM REEDSVILLE
PA WIND DAMAGE
0437 PM GALETON
PA WIND DAMAGE
0437 PM BRADFORD
PA FLOOD
0445 PM CURWENSVILLE
PA WIND DAMAGE
0446 PM GRANVILLE
PA WIND DAMAGE
0450 PM BRADFORD
PA WIND DAMAGE
0450 PM WALNUT
PA WIND DAMAGE
0500 PM WILLIAMSPORT
PA WIND DAMAGE
0515 PM MILTON
PA WIND DAMAGE
0520 PM HUGHSVILLE
PA WIND DAMAGE
0555 PM WICONISCO
PA WIND DAMAGE
0600 PM MT. JEWETT
PA WIND DAMAGE
0600 PM MIFFLINBURG
PA WIND DAMAGE
0600 PM SUNBURY
PA WIND DAMAGE
0625 PM WATROUS
PA WIND DAMAGE
NWUS51 KCTP 212250
PRELIMINARY LOCAL STORM REPORT
TIME(EDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
0255 PM TROUTVILLE
PA POSSIBLE FUNNEL
0312 PM CURWENSVILLE
PA WIND DAMAGE
0330 PM ST MARYS
PA WIND DAMAGE
0345 PM KANE
PA WIND DAMAGE
0345 PM GREENCASTLE
PA WIND DAMAGE
0345 PM PETERSBURG BOROUGH
PA WIND DAMAGE
0430 PM LOCK HAVEN
PA WIND DAMAGE
0430 PM BEAVER SPRINGS
PA WIND DAMAGE
0430 PM REEDSVILLE
PA WIND DAMAGE
0437 PM GALETON
PA WIND DAMAGE
0437 PM BRADFORD
PA FLOOD
0445 PM CURWENSVILLE
PA WIND DAMAGE
0446 PM GRANVILLE
PA WIND DAMAGE
0450 PM BRADFORD
PA WIND DAMAGE
0450 PM WALNUT &nb |