Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 16, NWS Philadelphia/Mount Holly

May 8, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at May 8, 2021, 3:43 PM EDT. It was in force for 62 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
May 8, 2021, 3:43 PM EDT (19:43 UTC)
Expired
May 8, 2021, 4:45 PM EDT
In force
62 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
34.0 mph

The radar

The Dover AFB radar (KDOX), 16 km from the middle of the area, began a volume at 19:44 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, 7.7 hours before the alert went out and 113 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 2021-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2021-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 47 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1134 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
47 m²/s²
0-3 km storm-relative helicity
47 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

339 
WHUS51 KPHI 081943
SMWPHI
ANZ430-431-082045-
/O.NEW.KPHI.MA.W.0016.210508T1943Z-210508T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
343 PM EDT Sat May 8 2021

The National Weather Service in Mount Holly NJ has issued a

* Special Marine Warning for...
  Delaware Bay...

* Until 445 PM EDT.

* At 342 PM EDT, strong thunderstorms were located along a line
  extending from 7 nm southwest of Ship John Shoal Light to 14 nm
  southwest of Bowers Beach, moving southeast at 25 knots.

  HAZARD...Wind gusts 34 knots or greater and small hail.

  SOURCE...Radar.

  IMPACT...Small craft could be damaged in briefly higher winds and 
           suddenly higher waves.

* Locations impacted include...
  Brown Shoal Light, Fourteen Foot Bank Light, Slaughter Beach,
  Bowers Beach, Miah Maull Light, Brandywine Shoal Light and Cross
  Ledge Light.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor until hazardous weather passes.

&&

LAT...LON 3929 7551 3907 7492 3867 7521 3868 7524
      3872 7524 3875 7520 3876 7530 3879 7531
      3883 7529 3894 7541 3899 7539 3903 7546
      3918 7547 3921 7557
TIME...MOT...LOC 1942Z 300DEG 25KT 3920 7548 3894 7567 

HAIL...<.75IN
WIND...>34KTS

$$

SFJ
2 follow-up statements
909 
FZUS71 KPHI 082004
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
404 PM EDT Sat May 8 2021

ANZ430-431-082045-
/O.CON.KPHI.MA.W.0016.000000T0000Z-210508T2045Z/
404 PM EDT Sat May 8 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 445 PM EDT...

For the following areas...
Delaware Bay waters north of East Point NJ to Slaughter Beach DE...
Delaware Bay waters south of East Point NJ to Slaughter Beach DE...

At 403 PM EDT, showers were located along a line extending from near
Cross Ledge Light to 9 nm west of Slaughter Beach, moving southeast
at 25 knots.

HAZARD...Wind gusts to 40 knots and small hail.

SOURCE...Radar indicated.

IMPACT...Small craft could be damaged in briefly higher winds and 
         suddenly higher waves.

Locations impacted include...
Brown Shoal Light, Fourteen Foot Bank Light, Slaughter Beach, Bowers
Beach, Miah Maull Light, Brandywine Shoal Light and Cross Ledge
Light.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor until hazardous weather passes.

&&

LAT...LON 3929 7551 3907 7492 3867 7521 3868 7524
      3872 7524 3875 7520 3876 7530 3879 7531
      3883 7529 3894 7541 3899 7539 3903 7546
      3918 7547 3921 7557
TIME...MOT...LOC 2003Z 300DEG 25KT 3913 7531 3887 7550 

HAIL...<.75IN
WIND...40KTS

$$

SFJ
647 
FZUS71 KPHI 082026
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
426 PM EDT Sat May 8 2021

ANZ430-431-082045-
/O.CON.KPHI.MA.W.0016.000000T0000Z-210508T2045Z/
426 PM EDT Sat May 8 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 445 PM EDT...

For the following areas...
Delaware Bay waters north of East Point NJ to Slaughter Beach DE...
Delaware Bay waters south of East Point NJ to Slaughter Beach DE...

At 426 PM EDT, strong thunderstorms were located along a line
extending from Fourteen Foot Bank Light to 7 nm south of Slaughter
Beach, moving southeast at 25 knots.

HAZARD...Wind gusts to 40 knots and small hail.

SOURCE...Radar indicated.

IMPACT...Small craft could be damaged in briefly higher winds and 
         suddenly higher waves.

Locations impacted include...
Brown Shoal Light, Miah Maull Light, Brandywine Shoal Light, Cross
Ledge Light, Fourteen Foot Bank Light and Slaughter Beach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor until hazardous weather passes.

&&

LAT...LON 3920 7527 3907 7492 3867 7521 3868 7524
      3872 7524 3875 7520 3876 7529 3879 7531
      3883 7529 3895 7532
TIME...MOT...LOC 2026Z 300DEG 25KT 3906 7515 3880 7534 

HAIL...<.75IN
WIND...40KTS

$$

SFJ

The office that day

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

IssuedProductOfficeCountiesLasted
May 8, 11:22 AM EDTSpecial Weather StatementPHIMonmouth38 min
May 8, 1:12 PM EDTSpecial Weather StatementPHIMonmouth33 min
May 8, 1:15 PM EDTAreal Flood AdvisoryPHIMiddlesex, Monmouth58 min
May 8, 1:45 PM EDTSpecial Weather StatementPHIOcean15 min
May 8, 2:01 PM EDTSpecial Weather StatementPHIOcean14 min
May 8, 2:34 PM EDTSmall Craft AdvisoryPHI7 hr
May 8, 2:42 PM EDTSpecial Weather StatementPHIMiddlesex, Monmouth, Morris48 min
May 8, 2:47 PM EDTSpecial Marine WarningPHI31 min
May 8, 3:04 PM EDTSpecial Weather StatementPHISalem26 min
May 8, 3:23 PM EDTSpecial Weather StatementPHISalem37 min
May 8, 3:46 PM EDTSpecial Weather StatementPHISomerset29 min
May 8, 3:53 PM EDTSpecial Marine WarningPHI56 min
May 8, 4:01 PM EDTSpecial Marine WarningPHI48 min
May 8, 4:16 PM EDTSpecial Weather StatementPHICumberland29 min
May 8, 4:21 PM EDTSpecial Weather StatementPHIHunterdon, Middlesex, Somerset24 min
May 8, 4:28 PM EDTSpecial Marine WarningPHI62 min
May 8, 4:46 PM EDTSpecial Weather StatementPHIHunterdon, Mercer, Middlesex, Somerset29 min
May 8, 5:22 PM EDTSpecial Marine WarningPHI53 min
May 8, 3:39 PM EDTSpecial Weather StatementPHIKent36 min
May 8, 3:54 PM EDTSpecial Weather StatementPHISussex36 min
May 8, 4:15 PM EDTSpecial Weather StatementPHISussex30 min
May 8, 4:33 PM EDTSpecial Weather StatementPHISussex27 min
May 8, 5:56 PM EDTSpecial Weather StatementPHIKent34 min

Nearby

Special Marine Warnings in New Jersey, 2021Every special marine warning in 2021

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.