Alert archive / Pennsylvania / Special Weather Statements in 2018

Special Weather Statement, NWS Philadelphia/Mount Holly

September 18, 20184 counties in Pennsylvania; Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this special weather statement at Sep 18, 2018, 2:09 AM EDT for 4 counties in Pennsylvania; Cecil County, Maryland. It was in force for 81 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
Sep 18, 2018, 2:09 AM EDT (06:09 UTC)
Expired
Sep 18, 2018, 3:30 AM EDT
In force
81 min
Issued by
NWS Philadelphia/Mount Holly

Counties Cecil County, MD, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Dover AFB radar (KDOX), 116 km from the middle of the area, began a volume at 06:08 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 6.2 hours before the alert went out and 160 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, Washington/Dulle, VA at 00:00Z on 2018-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 709 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, Washington/Dulle, VA at 00:00Z on 2018-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 178 square meters per square second.193958Sfc1 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
709 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
587 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
178 m²/s²
0-3 km storm-relative helicity
256 m²/s²
Significant tornado parameter
0.5
Supercell composite
4.8

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 Sep 18, 12:50 AM EDT, 1 hour 19 minutes earlier.

Area forecast discussion, Sep 18, 12:50 AM EDT, 1 hour 19 minutes before
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Hazardous weather outlook, Sep 17, 3:34 PM EDT, 10 hours 35 minutes before
Hazardous Weather Outlook
National Weather Service Mount Holly NJ
334 PM EDT Mon Sep 17 2018

DEZ001>003-MDZ008-012-015-019-020-NJZ001-007>010-012-013-015>023-027-
PAZ054-055-060>062-070-071-101>106-181945-
New Castle-Kent-Inland Sussex-Cecil-Kent MD-Queen Annes-Talbot-
Caroline-Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-
Western Monmouth-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Ocean-Cumberland-Atlantic-Cape May-
Southeastern Burlington-Carbon-Monroe-Berks-Lehigh-Northampton-
Delaware-Philadelphia-Western Chester-Eastern Chester-
Western Montgomery-Eastern Montgomery-Upper Bucks-Lower Bucks-
334 PM EDT Mon Sep 17 2018

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

.DAY ONE...This Afternoon and Tonight.

Periods of heavy rain and showers through tonight from the remnants
of Florence may result in localized flash flooding.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Some heavy rain Tuesday from the remnants of Florence and a cold
front may result in localized flash flooding.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

DEZ004-NJZ014-024>026-181945-
Delaware Beaches-Eastern Monmouth-Atlantic Coastal Cape May-
Coastal Atlantic-Coastal Ocean-
334 PM EDT Mon Sep 17 2018

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

.DAY ONE...This Afternoon and Tonight.

There is a moderate risk of dangerous rip currents.

Periods of heavy rain and showers through tonight from the remnants
of Florence may result in localized flash flooding.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Some heavy rain Tuesday from the remnants of Florence and a cold
front may result in localized flash flooding.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

ANZ430-431-450>455-181945-
Delaware Bay waters north of East Point NJ to Slaughter Beach DE-
Delaware Bay waters south of East Point NJ to Slaughter Beach DE-
Coastal waters from 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-
334 PM EDT Mon Sep 17 2018

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

.DAY ONE...This Afternoon and Tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

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, Sep 18, 1:13 AM EDT, 56 minutes before
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Special weather statement, Sep 18, 2:09 AM EDT, 0 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Sep 18, 4:13 AM EDTSpecial Weather StatementPHICamden, Gloucester, Salem92 min
Sep 18, 9:27 AM EDTFlash Flood WatchPHIBurlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex and 5 more6 hr
Sep 18, 10:59 AM EDTAreal Flood AdvisoryPHIHunterdon, Mercer, Middlesex, Monmouth, Somerset4 hr
Sep 18, 12:01 PM EDTFlash Flood WarningPHIMercer, Middlesex, Somerset4 hr
Sep 18, 12:16 PM EDTSpecial Weather StatementPHIMiddlesex29 min
Sep 18, 12:36 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester, Mercer, Middlesex, Monmouth and 2 more3 hr
Sep 18, 1:20 PM EDTSpecial Weather StatementPHIBurlington25 min
Sep 18, 1:35 PM EDTSpecial Marine WarningPHI55 min
Sep 18, 2:51 PM EDTSpecial Marine WarningPHI38 min
Sep 18, 2:55 PM EDTSpecial Weather StatementPHIOcean35 min
Sep 18, 3:02 PM EDTAreal Flood AdvisoryPHIBurlington, Ocean3 hr
Sep 18, 3:12 PM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Camden, Ocean47 min
Sep 18, 3:47 PM EDTSpecial Weather StatementPHIOcean28 min
Sep 18, 4:12 PM EDTSpecial Weather StatementPHIAtlantic33 min
Sep 18, 4:47 PM EDTAreal Flood AdvisoryPHIAtlantic, Cape May, Cumberland, Ocean2 hr
Sep 18, 5:17 PM EDTFlash Flood WarningPHIAtlantic113 min
Sep 18, 1:13 AM EDTSpecial Weather StatementPHIChester62 min
Sep 18, 2:38 AM EDTAreal Flood AdvisoryPHIChester, Montgomery4 hr
Sep 18, 6:27 AM EDTAreal Flood AdvisoryPHICarbon, Monroe4 hr
Sep 18, 10:57 AM EDTAreal Flood AdvisoryPHIBucks, Chester, Delaware, Montgomery, Philadelphia3 hr
Sep 18, 5:26 PM EDTSpecial Weather StatementPHISussex34 min

Nearby

Special Weather Statements in Pennsylvania, 2018Special Weather Statements in Maryland, 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.