Alert archive / Delaware / Special Weather Statements in 2018

Special Weather Statement, NWS Philadelphia/Mount Holly

August 31, 2018Kent County, Delaware

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 31, 2018, 11:53 AM EDT for Kent County, Delaware. It was in force for 37 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 31, 2018, 11:53 AM EDT (15:53 UTC)
Expired
Aug 31, 2018, 12:30 PM EDT
In force
37 min
Issued by
NWS Philadelphia/Mount Holly

County Kent County, DE

The radar

The Dover AFB radar (KDOX), 21 km from the middle of the area, began a volume at 15:53 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 3.9 hours before the alert went out and 120 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Wallops Is Stn, VA at 12:00Z on 2018-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 72 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Wallops Is Stn, VA at 12:00Z on 2018-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
72 J/kg
Mixed-layer CIN
-177 J/kg
Mixed-layer LCL
1245 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
89 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

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

NWS Philadelphia/Mount Holly wrote its last area forecast discussion before this special weather statement went out at Aug 31, 9:53 AM EDT, 2 hours earlier.

Area forecast discussion, Aug 31, 9:53 AM EDT, 2 hours before
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Hazardous weather outlook, Aug 31, 5:20 AM EDT, 6 hours 33 minutes before
Hazardous Weather Outlook
National Weather Service Mount Holly NJ
520 AM EDT Fri Aug 31 2018

NJZ001-007>010-012-PAZ054-055-061-062-010930-
Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-Carbon-Monroe-
Lehigh-Northampton-
520 AM EDT Fri Aug 31 2018

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

.DAY ONE...Today and Tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

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.

DEZ001>003-MDZ008-012-015-019-020-NJZ013-015>023-027-PAZ060-070-071-
101>106-010930-
New Castle-Kent-Inland Sussex-Cecil-Kent MD-Queen Annes-Talbot-
Caroline-Western Monmouth-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Ocean-Cumberland-Atlantic-Cape May-
Southeastern Burlington-Berks-Delaware-Philadelphia-Western Chester-
Eastern Chester-Western Montgomery-Eastern Montgomery-Upper Bucks-
Lower Bucks-
520 AM EDT Fri Aug 31 2018

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

.DAY ONE...Today and Tonight.

Some showers and thunderstorms today will be capable of very heavy
downpours leading to localized flooding especially in poor drainage
areas.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

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.

DEZ004-NJZ014-024>026-010930-
Delaware Beaches-Eastern Monmouth-Atlantic Coastal Cape May-
Coastal Atlantic-Coastal Ocean-
520 AM EDT Fri Aug 31 2018

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

.DAY ONE...Today and Tonight.

There is a moderate risk for the formation of dangerous rip currents
along the New Jersey shore and the Delaware Beaches through this
evening.

Some showers and thunderstorms today will be capable of very heavy
downpours leading to localized flooding especially in poor drainage
areas.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

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>455-010930-
Coastal waters from Sandy Hook to Manasquan Inlet NJ out 20 nm-
Coastal waters from Manasquan Inlet to Little Egg Inlet NJ out 20 nm-
Coastal waters from Little Egg Inlet to Great Egg Inlet NJ out 20 nm-
Coastal waters from Great Egg Inlet to Cape May NJ out 20 nm-
Coastal waters from Cape May NJ to Cape Henlopen DE out 20 nm-
Coastal waters from Cape Henlopen to Fenwick Island DE out 20 nm-
520 AM EDT Fri Aug 31 2018

This Hazardous Weather Outlook is for Atlantic coastal waters.

.DAY ONE...Today and Tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

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.

ANZ430-431-010930-
Delaware Bay waters north of East Point NJ to Slaughter Beach DE-
Delaware Bay waters south of East Point NJ to Slaughter Beach DE-
520 AM EDT Fri Aug 31 2018

This Hazardous Weather Outlook is for Delaware Bay Waters.

.DAY ONE...Today and Tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

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

Local storm report, Aug 31, 7:34 AM EDT, 4 hours 19 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
734 AM EDT FRI AUG 31 2018

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

0719 AM     HEAVY RAIN       SOUTHAMPTON TWP         39.91N  74.73W
08/31/2018  M3.58 INCH       BURLINGTON         NJ   TRAINED SPOTTER

&&

EVENT NUMBER PHI1801457

DAVIS
Local storm report, Aug 31, 8:57 AM EDT, 2 hours 56 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
857 AM EDT FRI AUG 31 2018

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

0850 AM     HEAVY RAIN       1 ESE THORNBURY TWP     39.91N  75.54W
08/31/2018  M2.00 INCH       DELAWARE           PA   TRAINED SPOTTER

            RAINFALL IN THORNTON IN 45 MINUTES.

&&

EVENT NUMBER PHI1801458

GORSE
Local storm report, Aug 31, 10:08 AM EDT, 1 hour 45 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1008 AM EDT FRI AUG 31 2018

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

0845 AM     FLASH FLOOD      THORNBURY TWP           39.93N  75.50W
08/31/2018                   DELAWARE           PA   TRAINED SPOTTER

            NUMEROUS ROADS IMPASSABLE DUE TO FLASH FLOODING IN
            THORNBURY TOWNSHIP WEST OF CHENEY ROAD. PICTURE ON
            SOCIAL MEDIA SHOWED FLOOD WATERS FLOWING ACROSS A
            ROADWAY. 2 INCHES OF RAIN FELL WITHIN 45 MINUTES.

&&

EVENT NUMBER PHI1801459

GORSE
Local storm report, Aug 31, 10:15 AM EDT, 1 hour 38 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1015 AM EDT FRI AUG 31 2018

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

0714 AM     HEAVY RAIN       EASTAMPTON TWP          39.99N  74.75W
08/31/2018  M4.99 INCH       BURLINGTON         NJ   MESONET

            4 INCHES OF RAIN FELL IN 90-MINUTE PERIOD ENDING 624
            AM.

0739 AM     HEAVY RAIN       2 SSE EASTAMPTON TWP    39.98N  74.73W
08/31/2018  M5.58 INCH       BURLINGTON         NJ   MESONET

            5.06 INCHES OF RAIN FELL IN 2-HR PERIOD ENDING 7 AM.

0742 AM     HEAVY RAIN       LUMBERTON               39.96N  74.79W
08/31/2018  M2.32 INCH       BURLINGTON         NJ   MESONET

            6-HOUR RAINFALL.

&&

EVENT NUMBER PHI1801460
EVENT NUMBER PHI1801461
EVENT NUMBER PHI1801462

JRK
Local storm report, Aug 31, 10:55 AM EDT, 58 minutes before
PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1055 AM EDT FRI AUG 31 2018

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

0714 AM     HEAVY RAIN       EASTAMPTON TWP          39.99N  74.75W
08/31/2018  M4.99 INCH       BURLINGTON         NJ   MESONET

            4 INCHES OF RAIN FELL IN 90-MINUTE PERIOD ENDING 624
            AM.

0719 AM     HEAVY RAIN       SOUTHAMPTON TWP         39.91N  74.73W
08/31/2018  M3.58 INCH       BURLINGTON         NJ   TRAINED SPOTTER

0739 AM     HEAVY RAIN       2 SSE EASTAMPTON TWP    39.98N  74.73W
08/31/2018  M5.58 INCH       BURLINGTON         NJ   MESONET

            5.06 INCHES OF RAIN FELL IN 2-HR PERIOD ENDING 7 AM.

0742 AM     HEAVY RAIN       LUMBERTON               39.96N  74.79W
08/31/2018  M2.32 INCH       BURLINGTON         NJ   MESONET

            6-HOUR RAINFALL.

0845 AM     FLASH FLOOD      THORNBURY TWP           39.93N  75.50W
08/31/2018                   DELAWARE           PA   TRAINED SPOTTER

            NUMEROUS ROADS IMPASSABLE DUE TO FLASH FLOODING IN
            THORNBURY TOWNSHIP WEST OF CHENEY ROAD. PICTURE ON
            SOCIAL MEDIA SHOWED FLOOD WATERS FLOWING ACROSS A
            ROADWAY. 2 INCHES OF RAIN FELL WITHIN 45 MINUTES.

0850 AM     HEAVY RAIN       1 ESE THORNBURY TWP     39.91N  75.54W
08/31/2018  M2.00 INCH       DELAWARE           PA   TRAINED SPOTTER

            RAINFALL IN THORNTON IN 45 MINUTES.

&&

EVENT NUMBER PHI1801460 PHI1801457 PHI1801461 PHI1801462 PHI1801459
PHI1801458

GORSE
Special weather statement, Aug 31, 11:53 AM EDT, 0 minutes before
Special Weather Statement
National Weather Service Mount Holly NJ
1153 AM EDT FRI AUG 31 2018

DEZ002-311630-
Kent-
1153 AM EDT FRI AUG 31 2018

...A STRONG THUNDERSTORM WILL AFFECT EAST CENTRAL KENT COUNTY...

At 1152 AM EDT, a strong thunderstorm was located near Harrington, or
13 miles south of Dover, and nearly stationary.

Winds up to 5 mph are possible with this storm. Numerous cloud to
ground lightning strikes can also be expected.

Locations impacted include...
Frederica and Riverview.

LAT...LON 3905 7552 3902 7538 3896 7539 3896 7558
TIME...MOT...LOC 1552Z 018DEG 49KT 3897 7551

jjm

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 31, 5:17 AM EDTAreal Flood AdvisoryPHIBurlington3 hr
Aug 31, 5:36 AM EDTFlash Flood WarningPHIBurlington3 hr
Aug 31, 6:27 AM EDTFlash Flood WarningPHIBurlington3 hr
Aug 31, 6:37 AM EDTSevere Thunderstorm WarningPHIBurlington, Ocean53 min
Aug 31, 7:34 AM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Camden2 hr
Aug 31, 9:29 AM EDTAreal Flood AdvisoryPHIBurlington119 min
Aug 31, 12:47 PM EDTSpecial Marine WarningPHI118 min
Aug 31, 1:22 PM EDTAreal Flood AdvisoryPHIMorris, Sussex, Warren4 hr
Aug 31, 4:30 PM EDTSpecial Marine WarningPHI90 min
Aug 31, 6:52 AM EDTAreal Flood AdvisoryPHIPhiladelphia4 hr
Aug 31, 7:55 AM EDTAreal Flood AdvisoryPHIDelaware3 hr
Aug 31, 10:09 AM EDTFlash Flood WarningPHIBerks7 hr
Aug 31, 10:14 AM EDTAreal Flood AdvisoryPHIChester3 hr
Aug 31, 1:54 PM EDTAreal Flood AdvisoryPHIBerks, Chester, Lehigh, Montgomery4 hr
Aug 31, 3:59 PM EDTFlash Flood WarningPHIBerks, Chester4 hr
Aug 31, 5:13 PM EDTAreal Flood WarningPHIBerks7 hr
Aug 31, 1:37 AM EDTSpecial Weather StatementPHISussex53 min
Aug 31, 10:57 AM EDTAreal Flood AdvisoryPHIKent107 min
Aug 31, 11:31 AM EDTFlash Flood WarningPHIKent11 hr
Aug 31, 12:00 PM EDTSevere Thunderstorm WarningPHIKent15 min
Aug 31, 12:15 PM EDTFlash Flood WarningPHIKent, Sussex7 hr
Aug 31, 12:28 PM EDTSpecial Weather StatementPHIKent32 min
Aug 31, 12:35 PM EDTSevere Thunderstorm WarningPHIKent, Sussex40 min
Aug 31, 12:54 PM EDTFlash Flood WarningPHISussex4 hr
Aug 31, 1:09 PM EDTSevere Thunderstorm WarningPHISussex51 min
Aug 31, 1:58 PM EDTSpecial Weather StatementPHISussex32 min
Aug 31, 4:27 PM EDTSpecial Weather StatementPHISussex18 min
Aug 31, 4:32 PM EDTFlash Flood WarningPHISussex4 hr
Aug 31, 4:41 PM EDTAreal Flood AdvisoryPHIKent, New Castle4 hr
Aug 31, 4:42 PM EDTSpecial Weather StatementPHISussex33 min
Aug 31, 5:00 PM EDTFlash Flood WarningPHINew Castle4 hr
Aug 31, 5:14 PM EDTSpecial Weather StatementPHISussex46 min
Aug 31, 5:38 PM EDTAreal Flood AdvisoryPHIKent, New Castle, Sussex4 hr
Aug 31, 5:48 PM EDTFlash Flood WarningPHISussex3 hr
Aug 31, 7:11 PM EDTAreal Flood WarningPHIKent, Sussex4 hr
Aug 31, 7:37 PM EDTFlash Flood WarningPHIKent, New Castle4 hr

Nearby

Special Weather Statements in Delaware, 2018Every special weather statement in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.