Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 137, NWS Philadelphia/Mount Holly

October 16, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Oct 16, 2021, 3:22 PM EDT. It was in force for 113 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Oct 16, 2021, 3:22 PM EDT (19:22 UTC)
Expired: Oct 16, 2021, 5:15 PM EDT
In force: 113 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.0 in
Wind: 40.0 mph

The radar

The Dover AFB radar (KDOX), 62 km from the middle of the area, began a volume at 19:24 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.

What was reported inside it

Time	Report	Where	Remark
Oct 16, 4:00 PM EDT	MARINE TSTM WIND 47	Lower Alloways Creek, NJ	NJ WEATHERNET SITE NJ74.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 7.4 hours before the alert went out and 161 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 914 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 50 m²/s²
0-3 km storm-relative helicity: 191 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

500 
WHUS51 KPHI 161922
SMWPHI
ANZ430-431-162115-
/O.NEW.KPHI.MA.W.0137.211016T1922Z-211016T2115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
322 PM EDT Sat Oct 16 2021

The National Weather Service in Mount Holly NJ has issued a

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

* Until 515 PM EDT.

* At 321 PM EDT, a front was located along a line extending from 14
  nm north of Northeast River to 8 nm east of Worton Point, moving 
  northeast at 55 knots. A line of heavy showers and isolated 
  thunderstorms was located along the leading edge of the front.

  HAZARD...Wind gusts to 40 knots and a sharp wind shift to 
           northwest.

  SOURCE...Radar.

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

* Locations impacted include...
  Fortesque Beach, Sea Breeze, Pea Patch Island, Fourteen Foot Bank
  Light, East Point, Woodland Beach, Stony Point, Miah Maull Light,
  Ship John Shoal Light, Brandywine Shoal Light, Cross Ledge Light
  and Reedy Point.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor immediately as gusty winds and high waves are
expected.

&&

LAT...LON 3963 7562 3975 7549 3960 7539 3954 7547
      3945 7538 3929 7516 3915 7487 3900 7495
      3888 7525 3913 7545 3950 7562
TIME...MOT...LOC 1921Z 219DEG 57KT 3976 7590 3931 7601 

HAIL...0.00IN
WIND...40KTS

$$

JEO

1 follow-up statement

956 
FZUS71 KPHI 162111
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
511 PM EDT Sat Oct 16 2021

ANZ430-431-162121-
/O.EXP.KPHI.MA.W.0137.000000T0000Z-211016T2115Z/
511 PM EDT Sat Oct 16 2021

...THE SPECIAL MARINE WARNING WILL EXPIRE AT 515 PM EDT...

The affected areas were... 
Delaware Bay...

The front has moved out of the area and no longer poses a significant
threat to boaters.

LAT...LON 3963 7562 3975 7549 3960 7539 3954 7547
      3945 7538 3929 7516 3915 7487 3900 7495
      3888 7525 3913 7545 3950 7562
TIME...MOT...LOC 2111Z 219DEG 57KT 3976 7590 3931 7601 

$$

JEO

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 16, 10:35 AM EDT	Coastal Flood Statement	PHI	Ocean	2 hr
Oct 16, 3:31 PM EDT	Severe Thunderstorm Warning	PHI	Salem	18 min
Oct 16, 3:41 PM EDT	Special Weather Statement	PHI	Hunterdon, Sussex, Warren	49 min
Oct 16, 4:02 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	43 min
Oct 16, 4:18 PM EDT	Special Weather Statement	PHI	Atlantic, Burlington, Camden, Cumberland, Gloucester, Mercer and 1 more	57 min
Oct 16, 5:10 PM EDT	Special Marine Warning	PHI		95 min
Oct 16, 5:29 PM EDT	Special Marine Warning	PHI		91 min
Oct 16, 6:09 PM EDT	Special Marine Warning	PHI		66 min
Oct 16, 6:52 PM EDT	Coastal Flood Statement	PHI	Ocean	4 hr
Oct 16, 1:39 PM EDT	Special Weather Statement	PHI	Berks	51 min
Oct 16, 2:32 PM EDT	Special Weather Statement	PHI	Berks, Lehigh	58 min
Oct 16, 2:44 PM EDT	Special Weather Statement	PHI	Chester	61 min
Oct 16, 3:40 PM EDT	Special Weather Statement	PHI	New Castle	50 min

Nearby

Special Marine Warnings in New Jersey, 2021 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.