Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 2, NWS Philadelphia/Mount Holly

January 20, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Jan 20, 2021, 1:00 PM EST. It was in force for 65 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
Jan 20, 2021, 1:00 PM EST (18:00 UTC)
Expired
Jan 20, 2021, 2:05 PM EST
In force
65 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.0 in
Wind
40.0 mph

The radar

The Philadelphia radar (KDIX), 74 km from the middle of the area, began a volume at 18:00 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

Brookhaven, NY (KOKX), launched 12:00Z, 6.0 hours before the alert went out and 143 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, Brookhaven, NY at 12:00Z on 2021-01-20Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2021-01-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -7 square meters per square second.1939587897117136Sfc1 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
1247 m above ground
0-6 km bulk shear
74 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
195 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

627 
WHUS51 KPHI 201800
SMWPHI
ANZ450>452-470>473-202000-
/O.NEW.KPHI.MA.W.0002.210120T1800Z-210120T2000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
100 PM EST Wed Jan 20 2021

The National Weather Service in Mount Holly NJ has issued a

* Special Marine Warning for...
  
Coastal waters from Sandy Hook to Great Egg Inlet NJ out 20 nm...
Outer waters from Sandy Hook to Cape May NJ out 20 to 40 nm...

* Until 300 PM EST.

* At 1256 PM EST, showers were located along a line extending from 6
  nm northeast of Shark River Reef to 8 nm southeast of Barnegat
  Light Reef to Little Egg Inlet, moving southeast at 30 knots.

  HAZARD...Wind gusts to 40 knots.

  SOURCE...Radar.

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

* Locations impacted include...
  Beach Haven, Barnegat Light, North Beach Haven, Garden State North
  Reef, Little Egg Reef, Shark River Reef, Little Egg Inlet, Ship
  Bottom, Barnegat Light Reef, Garden State South Reef, Harvey Cedars
  and Brigantine.

LAT...LON 3956 7334 3936 7344 3894 7378 3947 7444
      3989 7401 4027 7368 4026 7365 3994 7337
      3982 7331 3971 7330
TIME...MOT...LOC 1756Z 308DEG 28KT 4020 7360 3974 7387 3948 7431 

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

$$

Robertson
2 follow-up statements
446 
FZUS71 KPHI 201829
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
129 PM EST Wed Jan 20 2021

ANZ450-201839-
/O.CAN.KPHI.MA.W.0002.000000T0000Z-210120T2000Z/
129 PM EST Wed Jan 20 2021

...THE SPECIAL MARINE WARNING IS CANCELLED...

The affected areas were...

Coastal waters from Sandy Hook to Manasquan Inlet NJ out 20 nm...

The showers have moved out of the warned area and no longer pose a 
significant threat to boaters.

LAT...LON 3895 7377 3935 7422 3968 7373 4008 7350
      3994 7337 3982 7331 3971 7330 3956 7334
      3936 7344
TIME...MOT...LOC 1829Z 308DEG 28KT 4007 7338 3961 7365 3935 7409 

$$

ANZ451-452-470>473-202000-
/O.CON.KPHI.MA.W.0002.000000T0000Z-210120T2000Z/
129 PM EST Wed Jan 20 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 300 PM EST...

For the following areas...
Coastal waters from Little Egg Inlet to Great Egg Inlet NJ out 20
nm...
Coastal waters from Manasquan Inlet to Little Egg Inlet NJ out 20
nm...
Waters from Great Egg Inlet NJ to Cape May NJ out 20 to 40 nm...
Waters from Little Egg Inlet NJ to Great Egg Inlet NJ out 20 to 40 nm
from 20 to 40 NM...
Waters from Manasquan Inlet NJ to Little Egg Inlet NJ out 20 to 40
nm...
Waters from Sandy Hook NJ to Manasquan Inlet NJ out 20 to 40 nm...

At 129 PM EST, showers were located along a line extending from 14 nm
southwest of Buoy 44025 to 18 nm east of Garden State North Reef to 9
nm northeast of Atlantic City Reef, moving southeast at 30 knots.

HAZARD...Wind gusts to 40 knots.

SOURCE...Radar indicated.

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

The showers will remain over mainly open waters.

LAT...LON 3895 7377 3935 7422 3968 7373 4008 7350
      3994 7337 3982 7331 3971 7330 3956 7334
      3936 7344
TIME...MOT...LOC 1829Z 308DEG 28KT 4007 7338 3961 7365 3935 7409 

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

$$

Robertson
492 
FZUS71 KPHI 201905
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
205 PM EST Wed Jan 20 2021

ANZ451-452-470>473-201914-
/O.CAN.KPHI.MA.W.0002.000000T0000Z-210120T2000Z/
205 PM EST Wed Jan 20 2021

...THE SPECIAL MARINE WARNING IS CANCELLED...

The affected areas were... 

Coastal waters from Manasquan Inlet to Great Egg Inlet NJ out 20
nm...
Outer waters from Sandy Hook to Cape May NJ out 20 to 40 nm...

The showers have weakened and no longer pose a significant threat to
boaters.

LAT...LON 3895 7377 3935 7422 3968 7373 4008 7350
      3994 7337 3982 7331 3971 7330 3956 7334
      3936 7344
TIME...MOT...LOC 1900Z 308DEG 28KT 3992 7313 3946 7340 3920 7384 

$$

Robertson

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 20, 9:52 AM ESTSpecial Weather StatementPHIHunterdon, Somerset, Warren53 min
Jan 20, 10:42 AM ESTSpecial Weather StatementPHIHunterdon, Mercer, Middlesex, Monmouth, Morris, Somerset63 min
Jan 20, 12:02 PM ESTSpecial Marine WarningPHI58 min
Jan 20, 8:56 AM ESTSpecial Weather StatementPHICarbon, Monroe49 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.