National Weather Service United States Department of Commerce

Heat, Severe and Fire Weather

Excessive heat warnings persist across the Desert Southwest, while the heat and humidity lingers along the East Coast. An extensive zone of strong to severe thunderstorms with damaging winds and locally heavy rain are expected along a strong cold front from New England to the south-central Plains. Finally, elevated fire weather threats/red flag warnings are likely across the Inter-mountain West. Read More >

Overview

A large-scale trough in southeastern Canada and the northeastern portions of the United States was in place on 29 June 2019.  At the surface, a cold front was drifting southward in portions of New York and New England during the afternoon and evening hours. The environment to the south of the front and downstream of a midlevel vorticity maximum moving into the region became moderately unstable, and storms readily developed along ambient mesoscale boundaries.  Steep low-level lapse rates allowed for the mixing of strong downdrafts to the surface, with storms quickly organizing into linear bands or clusters as cold pools developed and congealed.  The most severe storms occurred in two corridors:  eastern Pennsylvania into northern New Jersey (where a differential heating boundary allowed for localized stronger shear) and in far southeast Pennsylvania and northern Delmarva eastward through central New Jersey (where an instability gradient developed during the afternoon).  Numerous reports of wind damage occurred in these corridors.  Meanwhile, more cellular convection developed in central Delmarva and southern New Jersey in advance of the two aforementioned wind-damage corridors.  In these areas, sporadic large hail occurred as well as a few microbursts. Interestingly, these predecessor storms appeared to rejuvenate the line of storms moving through the Delaware Valley, likely owing to convergence of outflow boundaries. Several additional reports of severe weather occurred in Burlington, Ocean, and Monmouth Counties as the line re-intensified as it approached the coast.

Note that this page will be updated with additional information in the coming days.

Image
Composite radar loop of the widespread severe storms on 29 June 2019.

Meteorological Environment/Setup

Synoptic Overview at 12z 29 June 2019 (courtesy of SPC)

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Figure 1: 250-mb analysis Figure 2: 300-mb analysis Figure 3: 500-mb analysis
 
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Figure 4: 700-mb analysis Figure 5: 850-mb analysis Figure 6: 925-mb analysis

Synoptic Overview at 00z 30 June 2019 (courtesy of SPC)

Environment Environment Environment
Figure 7: 250-mb analysis Figure 8: 300-mb analysis Figure 9: 500-mb analysis
 
Environment Environment Environment
Figure 10: 700-mb analysis Figure 11: 850-mb analysis Figure 12: 925-mb analysis
 

Surface Maps (courtesy of WPC)

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Figure 13: 15z surface map Figure 14: 18z surface map Figure 15: 21z surface map
 
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Figure 16: 00z surface map Figure 17: 03z surface map Figure 18: 06z surface map

Observed Soundings
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Figure 19: 12z Upton, NY sounding Figure 20: 12z Sterling, VA sounding Figure 21: 12z Wallops Island, VA sounding
Environment Environment Environment
Figure 22: 00z Upton, NY sounding Figure 23: 00z Sterling, VA sounding Figure 24: 00z Wallops Island, VA sounding

Preliminary Storm Reports

prelimreports prelimreports prelimreports
Figure 1: National Preliminary Reports 12z 29 June 2019 to 12z 30 June 2019 Figure 2: 1630z SPC Convective Outlook Figure 3: Zoomed Preliminary Reports for the same period.

Warning Information

prelimreports
Figure 1: Plot of local storm reports and storm-based warnings for the 29 June 2019 event. Click here for more information.

Preliminary Local Storm Reports

 

NWUS51 KPHI 010016
LSRPHI

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
816 PM EDT SUN JUN 30 2019

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

0251 PM     TSTM WND DMG     1 E CAYOTS              39.48N 75.83W
06/29/2019                   CECIL              MD   PUBLIC           

            DOWNED TREES RESULTED IN PROPERTY DAMAGE ON 
            WOODSTOCK FARM LANE. TIME ESTIMATED FROM 
            RADAR. 

0255 PM     TSTM WND DMG     2 ENE CAYOTS            39.49N 75.81W
06/29/2019                   CECIL              MD   PUBLIC           

            SEVERAL DOWNED TREES AND LIMBS ALONG STATE 
            HIGHWAY 310 SOUTH OF CHESAPEAKE CITY. TIME 
            ESTIMATED FROM RADAR. 

0312 PM     HAIL             SICKLERVILLE            39.72N 74.97W
06/29/2019  E0.75 INCH       CAMDEN             NJ   PUBLIC           

             

0316 PM     TSTM WND DMG     1 ENE BLANDON           40.44N 75.86W
06/29/2019                   BERKS              PA   FIRE DEPT/RESCUE 

            DOWNED TREE ON HOCH ROAD. TIME ESTIMATED 
            FROM RADAR. 

0317 PM     HAIL             1 E SICKLERVILLE        39.72N 74.96W
06/29/2019  M1.00 INCH       CAMDEN             NJ   PUBLIC           

            PHOTO SHOWING NICKEL TO QUARTER SIZE HAIL. 

0320 PM     HAIL             WOOLWICH TWP            39.75N 75.30W
06/29/2019  M0.70 INCH       GLOUCESTER         NJ   PUBLIC           

             

0322 PM     TSTM WND DMG     1 ENE MOHNTON           40.29N 75.97W
06/29/2019                   BERKS              PA   FIRE DEPT/RESCUE 

            DOWNED TREE ON WIRES ON WELSH ROAD IN CUMRU 
            TWP. TIME ESTIMATED FROM RADAR. 

0322 PM     TSTM WND DMG     KENHORST                40.31N 75.94W
06/29/2019                   BERKS              PA   FIRE DEPT/RESCUE 

            DOWNED TREE ONTO A HOUSE ON COMMONWEALTH 
            BLVD IN KENHORST BORO. TIME ESTIMATED FROM 
            RADAR. 

0324 PM     TSTM WND DMG     2 NE WEST SADSBURY TWP  40.01N 75.91W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE BLOCKING THE ROADWAY AT THE 
            INTERSECTION OF SANDY HILL ROAD AND TYLER 
            DRIVE. TIME ESTIMATED FROM RADAR. 

0326 PM     TSTM WND DMG     2 W WEST CALN TWP       40.01N 75.89W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE BLOCKING THE ROADWAY AT THE 
            INTERSECTION OF KINGS HIGHWAY AND ASH ROAD. 
            TIME ESTIMATED FROM RADAR. 

0326 PM     TSTM WND DMG     1 SW WEST BRANDYWINE TW 40.03N 75.84W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE ON CEDAR KNOLL ROAD IN WEST CALN 
            TWP. TIME ESTIMATED FROM RADAR. 

0329 PM     TSTM WND DMG     2 NNW ROBESON TWP       40.26N 75.88W
06/29/2019                   BERKS              PA   FIRE DEPT/RESCUE 

            DOWNED TREE AT THE INTERSECTION OF CHRISTY 
            COURT AND WHITE BEAR ROAD. TIME ESTIMATED 
            FROM RADAR. 

0329 PM     TSTM WND DMG     1 SSE PARKESBURG        39.95N 75.91W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE NEAR THE INTERSECTION OF 
            LIMESTONE ROAD AND OLD RACETRACK ROAD. TIME 
            ESTIMATED FROM RADAR.. 

0331 PM     TSTM WND DMG     1 SSE ATGLEN            39.94N 75.97W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREES AND POWER LINES ON AND NEAR 
            FALLOWFIELD ROAD. TIME ESTIMATED FROM RADAR. 

0331 PM     HAIL             WAGONTOWN               40.01N 75.85W
06/29/2019  E1.00 INCH       CHESTER            PA   PUBLIC           

             

0332 PM     TSTM WND DMG     1 SSE ALLENTOWN         40.59N 75.47W
06/29/2019                   LEHIGH             PA   PUBLIC           

            NUMEROUS TREES AND POWERLINES DOWN IN THE 
            AREA SOUTH OF SUSQUEHANNA ST. A FEW ROADS 
            BLOCKED. TIME ESTIMATED FROM RADAR. 

0333 PM     HAIL             COATESVILLE             39.98N 75.82W
06/29/2019  E1.00 INCH       CHESTER            PA   PUBLIC           

            TIME ESTIMATED FROM RADAR. 

0333 PM     TSTM WND DMG     1 S WEST BRANDYWINE TWP 40.02N 75.82W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE BLOCKING MONACY ROAD NEAR MANOR 
            ROAD. TIME ESTIMATED FROM RADAR. 

0335 PM     TSTM WND DMG     1 NNW UPPER MILFORD TWP 40.50N 75.53W
06/29/2019                   LEHIGH             PA   DEPT OF HIGHWAYS 

            DOWNED TREE IN WIRES AT THE INTERSECTION OF 
            CHESTNUT STREET AND KINGS HIGHWAY. LANE 
            CLOSURES IN PLACE. TIME ESTIMATED FROM 
            RADAR. 

0337 PM     TSTM WND DMG     1 SE ATGLEN             39.94N 75.96W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE ON GAP NEWPORT PIKE NEAR GLEN 
            RUN ROAD. TIME ESTIMATED FROM RADAR. 

0339 PM     TSTM WND DMG     1 W SALISBURY TWP       40.59N 75.44W
06/29/2019                   LEHIGH             PA   PUBLIC           

            SOCIAL MEDIA VIDEO FOOTAGE OF NUMEROUS TREES 
            DOWN AND PROPERTY DAMAGE IN THE POTTER 
            STREET AND TIOGA STREET SECTIONS OF 
            ALLENTOWN. TIME ESTIMATED FROM RADAR. 

0339 PM     TSTM WND DMG     2 SSW HANOVER TWP       40.65N 75.40W
06/29/2019                   NORTHAMPTON        PA   NEWSPAPER        

            DOWNED TREE ON JACKSONVILLE ROAD NEAR MACADA 
            ROAD. TIME ESTIMATED FROM RADAR. 

0340 PM     HAIL             1 NNE SOUTH HARRISON TW 39.72N 75.25W
06/29/2019  M1.00 INCH       GLOUCESTER         NJ   PUBLIC           

             

0340 PM     TSTM WND DMG     1 NE SOUTH HARRISON TWP 39.72N 75.25W
06/29/2019                   GLOUCESTER         NJ   TRAINED SPOTTER  

            TWO TREES BLOWN DOWN. 

0341 PM     TSTM WND DMG     2 S PARKESBURG          39.94N 75.92W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE BLOCKING LIMESTONE ROAD NEAR 
            HIGHLAND ROAD. TIME ESTIMATED FROM RADAR. 

0342 PM     TSTM WND DMG     2 NW BYRAM TWP          40.96N 74.74W
06/29/2019                   SUSSEX             NJ   PUBLIC           

            NUMEROUS TREES REPORTED DOWN IN THE AREA. 
            TIME ESTIMATED FROM RADAR. 

0345 PM     TSTM WND DMG     1 S BETHLEHEM TWP       40.64N 75.33W
06/29/2019                   NORTHAMPTON        PA   NEWSPAPER        

            SEVERAL REPORTS OF DOWNED TREES AND WIRES ON 
            FREEMANSBURG AVENUE. TIME ESTIMATED FROM 
            RADAR. 

0347 PM     TSTM WND DMG     EAST FALLOWFIELD TWP    39.95N 75.82W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE NEAR THE INTERSECTION OF 
            STRASBURG ROAD AND YOUNGSBURG ROAD. TIME 
            ESTIMATED FROM RADAR. 

0351 PM     TSTM WND DMG     COATESVILLE             39.98N 75.83W
06/29/2019                   CHESTER            PA   PUBLIC           

            CORRECTS PREVIOUS TSTM WND DMG REPORT FROM 
            COATESVILLE. PHOTO OF A LARGE TREE DOWN. 
            TIME ESTIMATED FROM RADAR. 

0351 PM     TSTM WND DMG     2 WNW CONOWINGO         39.68N 76.19W
06/29/2019                   CECIL              MD   PUBLIC           

            THUNDERSTORM OUTFLOW RESULTED IN A DOWNED 
            TREE AND WIRES ON CONOWINGO ROAD. TIME 
            ESTIMATED FROM RADAR. 

0351 PM     TSTM WND DMG     1 NNW EAST CALN TWP     40.04N 75.69W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE NEAR THE INTERSECTION OF WILLIAM 
            SALESBURY DRIVE AND HICKORY DRIVE. TIME 
            ESTIMATED FROM RADAR. 

0352 PM     TSTM WND DMG     1 SSW ALLENTOWN         40.59N 75.48W
06/29/2019                   LEHIGH             PA   PUBLIC           

            PHOTO SHOWS A LARGE TREE DOWN ON A FENCE AND 
            POWER LINES. TIME ESTIMATED FROM RADAR. 

0352 PM     HAIL             2 N COATESVILLE         40.01N 75.82W
06/29/2019  E0.25 INCH       CHESTER            PA   PUBLIC           

             

0354 PM     TSTM WND DMG     3 NNW EAST CALN TWP     40.06N 75.71W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE BLOCKING DORIAN MILL ROAD NEAR 
            ROBERT DEAN DRIVE. TIME ESTIMATED FROM 
            RADAR. 

0358 PM     TSTM WND DMG     2 ESE EAST COVENTRY TWP 40.19N 75.59W
06/29/2019                   CHESTER            PA   DEPT OF HIGHWAYS 

            DOWNED TREE IN WIRES AT THE INTERSECTION OF 
            BETHEL CHURCH ROAD AND KOLB ROAD. LANE 
            CLOSURES REQUIRED. TIME ESTIMATED FROM 
            RADAR. 

0358 PM     TSTM WND DMG     1 SSW SPRING CITY       40.17N 75.56W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE ON STONY RUN ROAD NEAR 
            SCHUYLKILL ROAD IN EAST VINCENT TWP. TIME 
            ESTIMATED FROM RADAR. 

0358 PM     TSTM WND DMG     1 NNW EAST CALN TWP     40.04N 75.69W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE NEAR THE INTERSECTION OF 
            WOODLAND DRIVE AND SANTILLO WAY. TIME 
            ESTIMATED FROM RADAR. 

0400 PM     TSTM WND DMG     PHILLIPSBURG            40.69N 75.20W
06/29/2019                   WARREN             NJ   COUNTY OFFICIAL  

            DOWNED TREE NEAR THE INTERSECTION OF HUDSON 
            STREET AND WASHINGTON STREET. TIME ESTIMATED 
            FROM RADAR. 

0402 PM     TSTM WND DMG     2 SE EXTON              40.01N 75.61W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE BLOCKING BOOT ROAD NEAR KING 
            ROAD IN WEST WHITELAND TWP. TIME ESTIMATED 
            FROM RADAR. 

0402 PM     TSTM WND DMG     2 N OAKS                40.16N 75.46W
06/29/2019                   MONTGOMERY         PA   COUNTY OFFICIAL  

            DOWNED TREE NEAR STELLAS WAY AND LEVEL ROAD. 
            TIME ESTIMATED FROM RADAR. 

0402 PM     HAIL             FAIRFAX                 39.79N 75.54W
06/29/2019  E0.75 INCH       NEW CASTLE         DE   PUBLIC           

            TIME ESTIMATED FROM RADAR. 

0402 PM     TSTM WND DMG     1 NW PLEASANT HILL      39.68N 75.92W
06/29/2019                   CECIL              MD   PUBLIC           

            SOCIAL MEDIA PHOTO OF LARGE TREE BLOWN DOWN 
            ACROSS BLUE BALL ROAD NEAR WHEATLEY ROAD. 
            MORE TREES REPORTED DOWN IN THE AREA. TIME 
            ESTIMATED FROM RADAR. 

0403 PM     TSTM WND DMG     1 W HELLERTOWN          40.58N 75.37W
06/29/2019                   NORTHAMPTON        PA   PUBLIC           

            LARGE TREE LIMBS DOWNED. TIME ESTIMATED FROM 
            RADAR. 

0405 PM     TSTM WND DMG     LANDENBERG              39.78N 75.77W
06/29/2019                   CHESTER            PA   PUBLIC           

            TREES DOWN. TIME ESTIMATED FROM RADAR. 

0406 PM     TSTM WND DMG     1 W GRADYVILLE          39.94N 75.48W
06/29/2019                   DELAWARE           PA   DEPT OF HIGHWAYS 

            DOWNED TREE ON STATE HIGHWAY 352 NEAR VALLEY 
            ROAD. ALL LANES CLOSED. TIME ESTIMATED FROM 
            RADAR. 

0406 PM     TSTM WND DMG     2 E PHILLIPSBURG        40.70N 75.17W
06/29/2019                   WARREN             NJ   COUNTY OFFICIAL  

            DOWNED TREE ON U.S. HIGHWAY 22 NEAR MEMORIAL 
            PARKWAY. TIME ESTIMATED FROM RADAR. 

0406 PM     TSTM WND DMG     WEST CHESTER            39.96N 75.60W
06/29/2019                   CHESTER            PA   PUBLIC           

            REPORTS OF DOWNED TREES AND LIMBS IN SEVERAL 
            LOCATIONS IN AND NEAR WEST CHESTER. TIME 
            ESTIMATED FROM SOCIAL MEDIA REPORTS AND 
            RADAR. 

0408 PM     TSTM WND DMG     1 WSW GRADYVILLE        39.94N 75.48W
06/29/2019                   DELAWARE           PA   DEPT OF HIGHWAYS 

            CORRECTS PREVIOUS TSTM WND DMG REPORT FROM 1 
            WSW GRADYVILLE. DOWNED TREE ON GRADYVILLE 
            ROAD NEAR VALLEY ROAD. ALL LANES CLOSED. 
            TIME ESTIMATED FROM RADAR. 

0408 PM     TSTM WND DMG     2 NNW PAOLI             40.06N 75.49W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE NEAR THE INTERSECTION OF VALLEY 
            ROAD AND SWEDESFORD ROAD. TIME ESTIMATED 
            FROM RADAR. 

0408 PM     TSTM WND DMG     1 SSW KENNETT SQUARE    39.83N 75.72W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE NEAR THE INTERSECTION OF ORIOLE 
            DRIVE AND CHANDLER MILL ROAD. TIME ESTIMATED 
            FROM RADAR. 

0412 PM     TSTM WND DMG     1 ENE BERWYN            40.05N 75.41W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE NEAR THE INTERSECTION OF UPPER 
            GULPH ROAD AND WENTWORTH ROAD. TIME 
            ESTIMATED FROM RADAR. 

0413 PM     TSTM WND DMG     BEAR                    39.63N 75.66W
06/29/2019                   NEW CASTLE         DE   PUBLIC           

            LARGE TREE LIMBS DOWN IN BEAR. TIME 
            ESTIMATED FROM RADAR. 

0414 PM     TSTM WND DMG     1 NW BROOKHAVEN         39.89N 75.40W
06/29/2019                   DELAWARE           PA   PUBLIC           

            DOWNED TREE ON STATE HIGHWAY 352 NEAR 
            MIDDLETOWN ROAD. ALL LANES CLOSED. TIME 
            ESTIMATED FROM RADAR. 

0414 PM     TSTM WND DMG     2 W WEST CONSHOHOCKEN   40.07N 75.34W
06/29/2019                   MONTGOMERY         PA   COUNTY OFFICIAL  

            DOWNED TREE BLOCKING INTERSTATE 76 EXIT RAMP 
            TO BALLIGOMINGO ROAD. TIME ESTIMATED FROM 
            RADAR. 

0414 PM     TSTM WND DMG     2 E BERWYN              40.05N 75.40W
06/29/2019                   CHESTER            PA   COUNTY OFFICIAL  

            DOWNED TREE NEAR THE INTERSECTION OF OLD 
            EAGLE SCHOOL ROAD AND VALLEY ROAD. TIME 
            ESTIMATED FROM RADAR. 

0415 PM     TSTM WND DMG     NEWARK                  39.68N 75.76W
06/29/2019                   NEW CASTLE         DE   TRAINED SPOTTER  

            TREE DAMAGE AND WINDS ESTIMATED TO BE 60-65 
            MPH. TIME ESTIMATED FROM RADAR. 

0415 PM     HAIL             GALLOWAY TWP            39.47N 74.51W
06/29/2019  E0.25 INCH       ATLANTIC           NJ   TRAINED SPOTTER  

             

0416 PM     TSTM WND DMG     1 E CONSHOHOCKEN        40.08N 75.28W
06/29/2019                   MONTGOMERY         PA   COUNTY OFFICIAL  

            DOWNED TREE AT BARREN HILL ROAD AND RIVER 
            ROAD. TIME ESTIMATED FROM RADAR. 

0416 PM     TSTM WND DMG     1 NNW GLADWYNE          40.05N 75.29W
06/29/2019                   MONTGOMERY         PA   COUNTY OFFICIAL  

            LARGE TREES DOWN NEAR STONY LANE. TIME 
            ESTIMATED FROM RADAR. 

0416 PM     HAIL             1 WNW SMITHVILLE        39.50N 74.48W
06/29/2019  E0.88 INCH       ATLANTIC           NJ   PUBLIC           

             

0418 PM     TSTM WND DMG     1 ENE LAWRENCE PARK     39.98N 75.32W
06/29/2019                   DELAWARE           PA   PUBLIC           

            LARGE LIMBS DOWNED FROM THE CANOPIES OF 
            SEVERAL OAK AND MAPLE TREES. TIME ESTIMATED 
            FROM RADAR. 

0418 PM     TSTM WND DMG     1 WSW GLADWYNE          40.03N 75.29W
06/29/2019                   MONTGOMERY         PA   COUNTY OFFICIAL  

            DOWNED TREE AND WIRES NEAR THE INTERSECTION 
            OF DOVE LAKE ROAD AND BLACK ROCK ROAD. TIME 
            ESTIMATED FROM RADAR. 

0419 PM     TSTM WND GST     3 NNE PENNSVILLE        39.69N 75.51W
06/29/2019  M58 MPH          SALEM              NJ   MESONET          

            PRIVATE WEATHER STATION. 

0420 PM     TSTM WND DMG     BYRAM TWP               40.94N 74.71W
06/29/2019                   SUSSEX             NJ   COUNTY OFFICIAL  

            TELEPHONE POLES AND WIRES DOWN. 

0422 PM     TSTM WND DMG     FRENCHTOWN              40.53N 75.06W
06/29/2019                   HUNTERDON          NJ   PUBLIC           

            PHOTO OF A LARGE TREE DOWN. TIME ESTIMATED 
            FROM RADAR. 

0422 PM     TSTM WND DMG     1 E ORELAND             40.11N 75.17W
06/29/2019                   MONTGOMERY         PA   COUNTY OFFICIAL  

            DOWNED TREE ON TENNIS AVENUE NEAR LIMEKILN 
            PIKE. TIME ESTIMATED FROM RADAR. 

0422 PM     TSTM WND DMG     1 SSE ARDMORE           40.00N 75.29W
06/29/2019                   MONTGOMERY         PA   COUNTY OFFICIAL  

            ROAD SIGN BLOWN OVER NEAR THE INTERSECTION 
            OF ARGYLE ROAD AND WYNNEWOOD ROAD. TIME 
            ESTIMATED FROM RADAR. 

0424 PM     HAIL             1 N MAGNOLIA            39.09N 75.47W
06/29/2019  E1.00 INCH       KENT               DE   PUBLIC           

            A TIN ROOF WAS DENTED FROM THE HAIL. TIME 
            ESTIMATED FROM RADAR. 

0424 PM     TSTM WND DMG     CHELTENHAM              40.06N 75.11W
06/29/2019                   MONTGOMERY         PA   COUNTY OFFICIAL  

            DOWNED TREE ON OAK LANE ROAD NEAR COVENTRY 
            ROAD. TIME ESTIMATED FROM RADAR. 

0426 PM     TSTM WND DMG     CHELTENHAM              40.05N 75.10W
06/29/2019                   MONTGOMERY         PA   COUNTY OFFICIAL  

            DOWNED TREE ON ASHMEAD ROAD NEAR TOOKANY 
            CREEK PARKWAY. TIME ESTIMATED FROM RADAR. 

0426 PM     TSTM WND DMG     1 NNW GERMANTOWN        40.05N 75.20W
06/29/2019                   PHILADELPHIA       PA   PUBLIC           

            SEVERAL TREES DOWN IN THIS AREA. TIME 
            ESTIMATED FROM RADAR. 

0428 PM     TSTM WND DMG     1 ENE CAYOTS            39.49N 75.83W
06/29/2019                   CECIL              MD   PUBLIC           

            SEVERAL TREES DOWN ALONG CAYOTS CORNER ROAD 
            BETWEEN MD 213 AND ST AUGUSTINE ROAD. TIME 
            ESTIMATED FROM RADAR. 

0428 PM     TSTM WND DMG     2 SW SCHOOLEYS MOUNTAIN 40.78N 74.85W
06/29/2019                   MORRIS             NJ   COUNTY OFFICIAL  

            DOWNED TREE NEAR THE INTERSECTION OF 
            PLEASANT GROVE ROAD AND STEPHENBURG ROAD. 
            TIME ESTIMATED FROM RADAR. 

0428 PM     TSTM WND DMG     1 SSE LOWER MORELAND TW 40.11N 75.06W
06/29/2019                   MONTGOMERY         PA   COUNTY OFFICIAL  

            LARGE TREE BLOWN DOWN BLOCKING STAHL ROAD 
            NEAR WELSH ROAD. TIME ESTIMATED FROM RADAR. 

0429 PM     TSTM WND GST     1 SW BARNEGAT LIGHT     39.75N 74.12W
06/29/2019  M70 MPH          OCEAN              NJ   MESONET          

            PRIVATE WEATHER STATION. 

0430 PM     TSTM WND DMG     1 NNW CHESAPEAKE CITY   39.54N 75.82W
06/29/2019                   CECIL              MD   PUBLIC           

            TREES DOWN IN THE AREA. TIME ESTIMATED FROM 
            RADAR. 

0430 PM     TSTM WND DMG     1 W STANHOPE            40.91N 74.72W
06/29/2019                   SUSSEX             NJ   DEPT OF HIGHWAYS 

            DOWNED TREE ON U.S. HIGHWAY 206 NORTH OF 
            INTERSTATE 80. ALL LANES CLOSED. TIME 
            ESTIMATED FROM RADAR. 

0430 PM     TSTM WND DMG     1 SW ROCKLEDGE          40.08N 75.10W
06/29/2019                   MONTGOMERY         PA   COUNTY OFFICIAL  

            DOWNED TREE NEAR THE INTERSECTION OF 
            CHANCELLOR AVENUE AND NORTHWOOD AVENUE. TIME 
            ESTIMATED FROM RADAR. 

0430 PM     TSTM WND DMG     TACONY                  40.03N 75.05W
06/29/2019                   PHILADELPHIA       PA   PUBLIC           

            REPORTS OF DOWNED TREES IN THE AREA. TIME 
            ESTIMATED FROM RADAR. 

0432 PM     HAIL             MOUNT HOLLY             39.99N 74.79W
06/29/2019  E0.70 INCH       BURLINGTON         NJ   PUBLIC           

            DIME SIZE HAIL REPORTED IN DOWNTOWN MOUNT 
            HOLLY. TIME ESTIMATED FROM RADAR. 

0432 PM     TSTM WND DMG     1 ENE PILESGROVE TWP    39.67N 75.37W
06/29/2019                   SALEM              NJ   PUBLIC           

            MPING REPORT OF TREE LIMBS DOWN AND PROPERTY 
            DAMAGE FROM THUNDERSTORM WINDS AT THIS 
            LOCATION. TIME ESTIMATED FROM RADAR. 

0432 PM     TSTM WND DMG     NORTHEAST PHILADELPHIA  40.09N 75.02W
06/29/2019                   PHILADELPHIA       PA   PUBLIC           

            SOCIAL MEDIA PHOTOS OF SEVERAL TREES DOWN IN 
            THE NORTHEAST PHILADELPHIA AREA. TIME 
            ESTIMATED FROM RADAR. 

0433 PM     MARINE TSTM WIND 2 E WARETOWN            39.79N 74.17W
06/29/2019  M46 MPH          ANZ451             NJ   MESONET          

            WEATHERFLOW GAUGE. 

0434 PM     TSTM WND DMG     MOUNT HOLLY             39.99N 74.79W
06/29/2019                   BURLINGTON         NJ   NWS EMPLOYEE     

            TREES AND LARGE TREE LIMBS DOWN. TIME 
            ESTIMATED FROM RADAR. 

0434 PM     HAIL             MOUNT HOLLY             39.99N 74.79W
06/29/2019  E0.75 INCH       BURLINGTON         NJ   PUBLIC           

            TIME ESTIMATED FROM RADAR. 

0434 PM     TSTM WND DMG     SUCCASUNNA              40.87N 74.65W
06/29/2019                   MORRIS             NJ   DEPT OF HIGHWAYS 

            DOWNED TREE ON STATE HIGHWAY 10 EASTBOUND 
            NEAR MAIN STREET. ALL LANES CLOSED. TIME 
            ESTIMATED FROM RADAR. 

0436 PM     TSTM WND DMG     2 WNW RANDOLPH, NJ      40.86N 74.60W
06/29/2019                   MORRIS             NJ   DEPT OF HIGHWAYS 

            DOWNED TREE ON STATE HIGHWAY 10 WESTBOUND 
            NEAR ARROWGATE DRIVE. ALL LANES CLOSED. TIME 
            ESTIMATED FROM RADAR. 

0436 PM     TSTM WND DMG     1 S LANDING             40.89N 74.66W
06/29/2019                   MORRIS             NJ   DEPT OF HIGHWAYS 

            DOWNED TREE ON U.S. HIGHWAY 46 EASTBOUND 
            NEAR MAIN STREET. ALL LANES CLOSED. TIME 
            ESTIMATED FROM RADAR. 

0440 PM     TSTM WND DMG     1 WSW MIDDLETOWN        39.45N 75.73W
06/29/2019                   NEW CASTLE         DE   PUBLIC           

            SEVERAL REPORTS OF TREE DAMAGE IN THE 
            MIDDLETOWN AREA. TIME ESTIMATED FROM RADAR. 

0440 PM     TSTM WND DMG     2 WSW MORRISVILLE       40.20N 74.81W
06/29/2019                   BUCKS              PA   TRAINED SPOTTER  

            DOWNED TREE SEVERELY DAMAGED AN APARTMENT 
            BUILDING. TIME ESTIMATED FROM RADAR. 

0441 PM     MARINE TSTM WIND 1 E BARNEGAT LIGHT      39.76N 74.09W
06/29/2019  M55 MPH          ANZ451             NJ   MESONET          

            WEATHERFLOW GAUGE. 

0441 PM     HAIL             CHERRY HILL             39.93N 75.03W
06/29/2019  M0.25 INCH       CAMDEN             NJ   TRAINED SPOTTER  

            LASTED FOR 10 MINUTES. 

0442 PM     TSTM WND DMG     ODESSA                  39.46N 75.66W
06/29/2019                   NEW CASTLE         DE   PUBLIC           

            MPING REPORT OF TREE LIMBS DOWN AND PROPERTY 
            DAMAGE FROM THUNDERSTORM WINDS AT THIS 
            LOCATION. TIME ESTIMATED FROM RADAR. 

0442 PM     TSTM WND DMG     1 NW LANGHORNE          40.18N 74.93W
06/29/2019                   BUCKS              PA   TRAINED SPOTTER  

            SEVERAL TREES AND POWER LINES DOWN. WINDS 
            BLEW DOWN A PARTY TENT. TIME ESTIMATED FROM 
            RADAR. 

0443 PM     TSTM WND DMG     1 SSE BENSALEM          40.10N 74.92W
06/29/2019                   BUCKS              PA   PUBLIC           

            MPING REPORT OF TREE LIMBS DOWN AND PROPERTY 
            DAMAGE FROM THUNDERSTORM WINDS. TIME 
            ESTIMATED FROM RADAR. 

0443 PM     TSTM WND DMG     TACONY                  40.03N 75.05W
06/29/2019                   PHILADELPHIA       PA   PUBLIC           

            TREE DOWN ON A TRUCK AND APARTMENT. TIME 
            ESTIMATED FROM RADAR. 

0445 PM     HAIL             RANDOLPH, NJ            40.85N 74.57W
06/29/2019  M0.25 INCH       MORRIS             NJ   TRAINED SPOTTER  

             

0445 PM     TSTM WND DMG     1 SSW PHILADELPHIA      39.94N 75.16W
06/29/2019                   PHILADELPHIA       PA   TRAINED SPOTTER  

            TREES AND POWER LINES DOWN BETWEEN 
            WASHINGTON AND CHRISTIAN STREETS. TIME 
            ESTIMATED FROM RADAR. 

0445 PM     TSTM WND DMG     1 S CHESTERTOWN         39.19N 76.06W
06/29/2019                   QUEEN ANNE'S       MD   PUBLIC           

            MULTIPLE TREES DOWN, ROOF SHINGLES AND 
            SIDING TORN OFF HOUSES, DAMAGE TO RIVER 
            DOCKS NEAR 322 RIVER ROAD. 

0446 PM     TSTM WND DMG     SHILOH                  39.46N 75.30W
06/29/2019                   CUMBERLAND         NJ   BROADCAST MEDIA  

            DOWNED TREE AT A RESIDENCE. TIME ESTIMATED 
            FROM RADAR. 

0447 PM     TSTM WND DMG     HOPEWELL                40.39N 74.76W
06/29/2019                   MERCER             NJ   PUBLIC           

            PHOTO OF A LARGE TREE DOWN OVER A ROADWAY 
            AND LIMB DOWN ON A CAR. TIME ESTIMATED FROM 
            RADAR. 

0448 PM     TSTM WND DMG     MORRISVILLE             40.21N 74.77W
06/29/2019                   BUCKS              PA   PUBLIC           

            TREES DOWN. TIME ESTIMATED FROM RADAR. 

0450 PM     HAIL             1 W MOUNT LAUREL        39.94N 74.91W
06/29/2019  E0.75 INCH       BURLINGTON         NJ   PUBLIC           

             

0454 PM     TSTM WND DMG     1 N BASKING RIDGE       40.72N 74.55W
06/29/2019                   SOMERSET           NJ   PUBLIC           

            MPING REPORT OF TREE LIMBS DOWN AND PROPERTY 
            DAMAGE FROM THUNDERSTORM DAMAGE AT THIS 
            LOCATION. TIME ESTIMATED FROM RADAR. 

0455 PM     TSTM WND DMG     BERNARDS TWP            40.70N 74.55W
06/29/2019                   SOMERSET           NJ   PUBLIC           

            PHOTOS OF SEVERAL TREES DOWN IN THE AREA. 
            TIME ESTIMATED FROM RADAR. 

0456 PM     TSTM WND DMG     MORRISTOWN              40.79N 74.47W
06/29/2019                   MORRIS             NJ   DEPT OF HIGHWAYS 

            DOWNED TREE ON INTERSTATE 287 NORTHBOUND 
            RAMP TO EXIT 36. TIME ESTIMATED FROM RADAR. 

0456 PM     TSTM WND DMG     BASKING RIDGE           40.71N 74.55W
06/29/2019                   SOMERSET           NJ   PUBLIC           

            A TREE AND A FEW LARGE LIMBS DOWN. TIME 
            ESTIMATED FROM RADAR. 

0457 PM     TSTM WND DMG     JACKSONVILLE            40.00N 74.78W
06/29/2019                   BURLINGTON         NJ   PUBLIC           

            A TREE FELL ONTO A HOUSE IN MOUNT HOLLY. 
            TIME ESTIMATED FROM RADAR. 

0500 PM     HAIL             BROWNS MILLS            39.97N 74.58W
06/29/2019  E0.70 INCH       BURLINGTON         NJ   PUBLIC           

            TIME ESTIMATED FROM RADAR. 

0500 PM     TSTM WND DMG     2 S MONROE TWP          39.64N 74.98W
06/29/2019                   GLOUCESTER         NJ   PUBLIC           

            MPING REPORT OF TREES AND POWER LINES DOWN 
            AT THIS LOCATION. TIME ESTIMATED FROM RADAR. 

0502 PM     HAIL             1 E WYOMING             39.12N 75.55W
06/29/2019  E0.25 INCH       KENT               DE   PUBLIC           

             

0505 PM     TSTM WND DMG     BROWNS MILLS            39.96N 74.58W
06/29/2019                   BURLINGTON         NJ   PUBLIC           

            PHOTO OF SEVERAL HARDWOOD TREES DOWN IN 
            COUNTRY LAKES. TIME ESTIMATED FROM RADAR. 

0506 PM     TSTM WND DMG     2 NW WRIGHTSTOWN        40.06N 74.65W
06/29/2019                   BURLINGTON         NJ   DEPT OF HIGHWAYS 

            DOWNED TREE ON STATE HIGHWAY 68 NEAR 
            MONMOUTH ROAD. ALL LANES CLOSED. TIME 
            ESTIMATED FROM RADAR. 

0506 PM     TSTM WND DMG     1 NNE PEMBERTON         39.99N 74.67W
06/29/2019                   BURLINGTON         NJ   LAW ENFORCEMENT  

            FORT DIX ROAD CLOSED BETWEEN POINTVILLE ROAD 
            AND ODD FELLOWS ROAD FROM DOWNED TREES. TIME 
            ESTIMATED FROM RADAR. 

0507 PM     TSTM WND DMG     1 W NORTH PLAINFIELD    40.62N 74.44W
06/29/2019                   SOMERSET           NJ   PUBLIC           

            PHOTOS OF MULTIPLE TREES DOWN. TIME 
            ESTIMATED FROM RADAR. 

0509 PM     TSTM WND DMG     2 W ESTELL MANOR        39.38N 74.86W
06/29/2019                   CUMBERLAND         NJ   LAW ENFORCEMENT  

            REPORTS OF TREES DOWN NEAR AND WEST OF 
            ESTELL MANOR. TIME ESTIMATED FROM RADAR. 

0510 PM     MARINE TSTM WIND FORTESCUE               39.24N 75.18W
06/29/2019  M48 MPH          CUMBERLAND         NJ   MESONET          

            NJWXNET SENSOR. 

0510 PM     HAIL             2 NNW HIGHLAND PARK     40.52N 74.43W
06/29/2019  E0.25 INCH       MIDDLESEX          NJ   TRAINED SPOTTER  

             

0511 PM     TSTM WND DMG     EDISON                  40.54N 74.38W
06/29/2019                   MIDDLESEX          NJ   TRAINED SPOTTER  

            TREES SPLIT. TIME ESTIMATED FROM RADAR. 

0513 PM     TSTM WND DMG     METUCHEN                40.54N 74.36W
06/29/2019                   MIDDLESEX          NJ   TRAINED SPOTTER  

            REPORT OF A LARGE TREE DOWN BLOCKING BOTH 
            DIRECTION OF MIDDLESEX AVENUE IN METUCHEN. 
            TIME ESTIMATED FROM RADAR. 

0514 PM     HAIL             DOVER                   39.16N 75.53W
06/29/2019  M1.00 INCH       KENT               DE   TRAINED SPOTTER  

            PEA TO QUARTER SIZE HAIL FELL FROM 5:14 TO 
            5:22 PM. 

0515 PM     TSTM WND DMG     1 NE ISELIN             40.58N 74.31W
06/29/2019                   MIDDLESEX          NJ   DEPT OF HIGHWAYS 

            DOWNED TREE ON STATE HIGHWAY 27 NEAR NEW 
            DOVER ROAD. TIME ESTIMATED FROM RADAR. 

0515 PM     MARINE TSTM WIND FORTESCUE               39.24N 75.17W
06/29/2019  M43 MPH          CUMBERLAND         NJ   MESONET          

             

0519 PM     HAIL             1 SE METUCHEN           40.53N 74.36W
06/29/2019  E0.75 INCH       MIDDLESEX          NJ   TRAINED SPOTTER  

             

0521 PM     TSTM WND GST     PORT READING            40.57N 74.24W
06/29/2019  M68 MPH          MIDDLESEX          NJ   TRAINED SPOTTER  

             

0534 PM     MARINE TSTM WIND SEASIDE PARK            39.94N 74.07W
06/29/2019  M41 MPH          OCEAN              NJ   MESONET          

            WEATHERFLOW GAUGE. 

0534 PM     MARINE TSTM WIND 1 ENE LANOKA HARBOR     39.87N 74.14W
06/29/2019  M44 MPH          OCEAN              NJ   MESONET          

            WEATHERFLOW GAUGE. 

0536 PM     TSTM WND GST     SANDY HOOK              40.47N 74.01W
06/29/2019  M61 MPH          MONMOUTH           NJ   MESONET          

             

0536 PM     HAIL             EATONTOWN               40.31N 74.06W
06/29/2019  E1.75 INCH       MONMOUTH           NJ   PUBLIC           

            TIME ESTIMATED FROM RADAR. 

0537 PM     HAIL             WEST LONG BRANCH        40.29N 74.01W
06/29/2019  E1.75 INCH       MONMOUTH           NJ   PUBLIC           

            GOLF BALL SIZE HAIL IN WEST LONG BRANCH. 
            TIME ESTIMATED FROM RADAR. 

0538 PM     TSTM WND DMG     1 ENE ASBURY PARK       40.22N 74.00W
06/29/2019                   MONMOUTH           NJ   BROADCAST MEDIA  

            DAMAGE TO AN OUTDOOR STAGE AND EQUIPMENT 
            OWING TO THUNDERSTORM WINDS. TIME ESTIMATED 
            FROM RADAR. 

0539 PM     MARINE TSTM WIND BRICK                   40.01N 74.06W
06/29/2019  M55 MPH          OCEAN              NJ   MESONET          

            WEATHERFLOW GAUGE. 

0540 PM     TSTM WND DMG     MIDDLETOWN              40.41N 74.13W
06/29/2019                   MONMOUTH           NJ   PUBLIC           

            SEVERAL DOWNED TREES, BRANCHES, AND POWER 
            LINES REPORTED. TIME ESTIMATED FROM RADAR. 

0540 PM     MARINE TSTM WIND 1 ESE MANASQUAN         40.12N 74.03W
06/29/2019  M43 MPH          MONMOUTH           NJ   MESONET          

             

0542 PM     MARINE TSTM WIND 2 WSW SHIP BOTTOM       39.64N 74.21W
06/29/2019  M52 MPH          ANZ451             NJ   MESONET          

            WEATHERFLOW GAUGE. 

0542 PM     MARINE TSTM WIND ATLANTIC CITY           39.38N 74.42W
06/29/2019  M40 MPH          ANZ452             NJ   MESONET          

             

0543 PM     MARINE TSTM WIND 2 NNE STRATHMERE        39.22N 74.64W
06/29/2019  M40 MPH          CAPE MAY           NJ   MESONET          

            WEATHERFLOW GAUGE. 

0544 PM     MARINE TSTM WIND 2 SE PLEASANTVILLE      39.37N 74.50W
06/29/2019  M39 MPH          ATLANTIC           NJ   MESONET          

            WEATHERFLOW GAUGE. 

0545 PM     MARINE TSTM WIND 1 NNW SEA ISLE CITY     39.17N 74.70W
06/29/2019  M43 MPH          ANZ453             NJ   MESONET          

            WEATHERFLOW GAUGE. 

0545 PM     TSTM WND GST     TILGHMAN                38.72N 76.33W
06/29/2019  M63 MPH          TALBOT             MD   MESONET          

            MDDOT GAUGE. 

0545 PM     TSTM WND DMG     EATONTOWN               40.31N 74.06W
06/29/2019                   MONMOUTH           NJ   PUBLIC           

            SEVERAL REPORTS OF TREES AND LIMBS DOWN IN 
            EATONTOWN. TIME ESTIMATED FROM RADAR. 

0545 PM     MARINE TSTM WIND MANTOLOKING             40.04N 74.05W
06/29/2019  M56 MPH          OCEAN              NJ   MESONET          

             

0545 PM     MARINE TSTM WIND NORTH WILDWOOD          39.01N 74.80W
06/29/2019  M47 MPH          CAPE MAY           NJ   MESONET          

             

0545 PM     MARINE TSTM WIND 1 ENE CAPE MAY POINT    38.94N 74.94W
06/29/2019  M39 MPH          CAPE MAY           NJ   MESONET          

             

0545 PM     TSTM WND DMG     2 NNE TOMS RIVER        39.97N 74.18W
06/29/2019                   OCEAN              NJ   FIRE DEPT/RESCUE 

            SEVERAL REPORTS OF TREES AND WIRES DOWN IN 
            THIS AREA FROM 530 TO 600 PM. TIME BASED ON 
            A COMBINATION OF RADAR, NEARBY SURFACE 
            OBSERVATIONS, AND SOCIAL MEDIA REPORTS. 

0546 PM     TSTM WND DMG     1 SSW TOMS RIVER        39.94N 74.20W
06/29/2019                   OCEAN              NJ   TRAINED SPOTTER  

            MULTIPLE TREES DOWN ON HOMES WITH WIRES DOWN 
            THROUGHOUT SOUTH TOMS RIVER. 

0554 PM     MARINE TSTM WIND CAPE MAY HARBOR         38.95N 74.89W
06/29/2019  M54 MPH          CAPE MAY           NJ   MESONET          

             

0559 PM     MARINE TSTM WIND 2 WNW LEWES             38.79N 75.16W
06/29/2019  M56 MPH          SUSSEX             DE   MESONET          

            WEATHERFLOW GAUGE. 

0600 PM     MARINE TSTM WIND 1 ENE LEWES             38.78N 75.12W
06/29/2019  M46 MPH          ANZ431             DE   MESONET          

             

0602 PM     MARINE TSTM WIND 1 SSW NORTH CAPE MAY    38.97N 74.96W
06/29/2019  M59 MPH          CAPE MAY           NJ   MESONET          

            WEATHERFLOW GAUGE. 

0602 PM     TSTM WND GST     1 SSW NORTH CAPE MAY    38.97N 74.96W
06/29/2019  M59 MPH          CAPE MAY           NJ   MESONET          

            WEATHERFLOW GAUGE. 

0608 PM     MARINE TSTM WIND INDIAN BEACH            38.68N 75.08W
06/29/2019  M49 MPH          SUSSEX             DE   MESONET          

            WEATHERFLOW GAUGE. 


&&

$$

CMS/ADS/TCD

Radar Interrogation

Chester County Downbursts and Hail

Environment Environment Environment
Figure 1: KDIX radar reflectivity factor (top left), base velocity (top right), differential reflectivity (ZDR; bottom left), and correlation coefficient (CC; bottom right) for the 2.4 degree elevation angle valid at 1917 UTC 29 June 2019. This elevation scan is around 20,000 to 25,000 feet above the ground in the western portions of Chester County and adjacent areas. The radar reflectivity factor is greater than 70 dBZ with the storm in eastern Lancaster County (just northeast of Quarryville), which is strongly indicative of impending severe weather (and sizable hail lofted by the updraft). Though range folding is occurring in the region of the storm of interest (note the band of purple in the ZDR and CC images), there are indications of a three-body scatter spike to the west of the storm (low CC west of Quarryville). The storm northwest of Coatesville is also likely severe, with 60-65 dBZ observed at these heights. Several reports of severe weather occurred with these two storms in the 15 minutes following this scan. Figure 2: Same as Fig. 1, valid at 1930 UTC 29 June 2019. The higher reflectivities have diminished but remain quite high (55-60 dBZ) at the 20,000-25,000 foot level, indicating severe weather is still likely with both storms. Another storm is developing near Honey Brook. A mere 15 minutes later, the characteristics of the storms aloft had changed dramatically. The lowering of the reflectivity at this level is actually indicative of the heaviest precipitation descending to the ground (and is correlated strongly with the timing of the severe reports from these storms). The nature of these storms is pulse-like; that is, the storm intensifies rapidly, with high reflectivities aloft that descend to the ground quickly (followed by weakening of the storm). Figure 3: Same as Fig. 1, valid at 1942 UTC 29 June 2019. Note the Honey Brook storm is now the most intense aloft, whereas the other two storms continue to exhibit lowering reflectivities (as the downdrafts continue to descend). Severe reports continued with all three storms in Chester County at this point, with widespread tree damage across the county.
Environment Environment Environment
Figure 4: As in Fig. 1, looped from 1914 UTC to 1954 UTC 29 June 2019, for the 0.5 degree elevation angle, which ends up being about 5000-5500 feet above the ground in Chester County. We see the initially distinct storms west of Coatesville and east of Quarryville quickly congeal as they progress into west-central Chester County. Meanwhile, the developing storm near Honey Brook quickly intensifies and propagates downstream rapidly, with the storms forming a loosely organized band by the end of the animation. Note how each of the storms pulses upward and then downward in intensity (given the increasing and then decreasing reflectivity), with new development on the flanks of the antecedent cells. The process of convective regeneration is critical to the maintenance of the storms and to the increased organization with time. The individual updrafts and downdrafts generally last about 30 to 45 minutes, but the rain-cooled air within the downdraft (a so-called cold pool) impinges upon unstable air surrounding the initial storm, forcing new updrafts to develop. This process continues until insufficient instability exists to generate subsequent updrafts. As the cold pools expand, the storms increasingly congeal/organize, and larger-scale flow develops. This is especially apparent with the northern-most cell in the animation, with base velocities noticeably increasing as the storm intensifies and then grows/congeals with the storms to the south. As this convective evolution continues, the localized wind damage with the initial cells becomes more widespread as the storms organize. Numerous instances of wind damage occur between Kennett Square and Phoenixville as a result. Figure 5: KDIX cross-section of radar reflectivity factor for the cell east of Quarryville, PA, in Lancaster and Chester Counties at 1926 UTC on 29 June 2019. Radar reflectivity factor reaches 70 dBZ up to 20,000 feet and 60 dBZ up to 35,000 feet (indicative of an intense updraft). Notably, the storm exhibits little vertical tilt (i.e., the radar reflectivity generally is upright). This is indicative of weak vertical shear and explains why the individual updrafts of storms intensified and diminished relatively quickly. Figure 6: Same as Fig. 5, valid at 1939 UTC 29 June 2019. The same storm about 15 minutes later is ultimately collapsing, with the highest reflectivity near the ground now and much weaker reflectivity (though still relatively strong, in general) aloft. New updrafts are generating downstream and on the north/south sides of the storm, as the current storm's cold pool forces unstable air upward.

Burlington/Ocean County Wind Damage

Environment
Figure 7: As in Fig. 4, valid from 2046 to 2121 UTC 29 June 2019. The loosely organized line of storms at the beginning of the animation is moving across the Delaware River. The storms have become more cellular and less organized; however, the cold pool remains strong, with severe winds reported in much of southeastern Bucks and northeastern Philadelphia Counties. However, the winds diminish somewhat as the outflow crosses into New Jersey. Meanwhile, clusters of storms have developed near and east of Mount Holly to central portions of Ocean County. The cell immediately west of the radar (KDIX) has generated a microburst (Note the localized very strong base velocities that actually fold from green to red colors as the storm approaches KDIX; this microburst actually started before the animation, in the Mount Holly area.), with several reports of wind damage in this general vicinity. The storm also generates an outflow boundary that propagates northward into Monmouth County and westward toward the line of storms. This outflow boundary serves to rejuvenate the loosely organized storms in western Burlington County, and more wind damage occurs east of Mount Holly as the line re-intensifies. Additionally, storms develop along the intersection of outflow boundaries northward into Monmouth County near the end of the animation. These storms became severe subsequent to the animation shown here as they approached the coast, with several reports of wind damage from Sandy Hook to Asbury Park. Near the end of the animation, there are two distinct lines of wind maxima. One is approaching Toms River as the storm that produced a microburst in Burlington County continues to be severe as it approaches coastal Ocean County (several reports of wind damage in this area). The second is approaching the radar, with sporadic reports of gusty/strong winds and sporadic damage in the Pemberton, Browns Mills, and Fort Dix areas.

North New Jersey Wind Damage and Hail

Environment
Figure 8: As in Fig. 4, valid from 2016 to 2056 UTC 29 June 2019. Storms had generated on an ambient surface boundary (aided in part from differential heating) from southern Sussex County through northern Morris County. The storms intensify rapidly in southeast Sussex County, in an environment of moderate instability and locally stronger shear (aided by the preexisting boundary and somewhat stronger deep-layer flow in this region versus farther south). The storm produced significant wind damage in Byram Township and Stanhope in Sussex County and continued to produce tree damage in much of Morris County. Sub-severe hail was also reported in western Morris County, timed closely with the storm's appearance of stronger rotation (as evident with base velocities) and non-uniform beam filling seen down-radial (northwest) of the storm in CC at the time the strongest reflectivities occurred. Radar did not exhibit much indication of severe hail, which was consistent with ground reports. As the cold pool strengthened, additional storms to the south rapidly intensified with the added lift provided by the strong downdraft generated to the north. A line of storms formed with an apparent bowing segment near and northwest of Morristown, where a maximum in wind-damage reports occurred. As the line moved southeast, additional damage reports were received from northern Somerset and northern Middlesex Counties.