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Marine Weather Message

The Marine Weather Message (MWW) informs mariners of adverse marine weather hazards and serves as a dedicated long duration marine watch, warning and advisory product. The MWW implements the operational Valid Time Event Code (VTEC) for all long term marine Watch, Warning and Advisory events. This includes tropical cyclone watches/warnings. The MWW is patterned after the winter weather watch/warning/advisory bulletin (WSW) and the non-precipitation watch/warning/advisory bulletin (NPW).

The MWW does not include information on short duration events such as severe thunderstorms and waterspouts. That type of information is included in Special Marine Warnings, which is not a part of the MWW. 

Current MWW products as well as most other Marine forecast and warning products

This product contains the following suite of marine watch, warning and advisory events:

Marine Watches

  • Hurricane Fore Wind Watch
  • Storm Watch
  • Gale Watch
  • Hazardous Seas Watch
  • Heavy Freezing Spray Watch
  • Tropical Storm Watch
  • Hurricane Watch
  • Storm Surge Watch

Marine Warnings

  • Hurricane Force Wind Warning
  • Storm Warning
  • Gale Warning
  • Hazardous Seas Warning
  • Heavy Freezing Spray Warning
  • Tropical Storm Warning
  • Hurricane Warning
  • Storm Surge Warning

Marine Advisories

  • Ashfall Advisory
  • Brisk Wind Advisory
  • Dense Fog Advisory
  • Dense Smoke Advisory
  • Freezing Spray Advisory
  • Low Water Advisory
  • Small Craft Advisory

Official NWSI 10-315, Marine Weather Message MWW Directive

Use the following product headers in communications databases to begin receiving the MWW

NWS Eastern Region
Local Office WMO Heading AWIPS ID
TAUNTON MA WHUS71 KBOX MWWBOX
BUFFALO NY WHUS71 KBUF MWWBUF
CHARLESTON SC WHUS72 KCHS MWWCHS
CLEVELAND OH WHUS71 KCLE MWWCLE
NEW YORK NY WHUS71 KOKX MWWOKX
PHILADELPHIA PA WHUS71 KPHI MWWPHI
CARIBOU ME WHUS71 KCAR MWWCAR
GRAY/PORTLAND ME WHUS71 KGYX MWWGYX
WILMINGTON NC WHUS72 KILM MWWILM
NEWPORT NC WHUS72 KMHX MWWMHX
WAKEFIELD VA WHUS71 KAKQ MWWAKQ
STERLING VA WHUS71 KLWX MWWLWX

 

NWS Central Region
Local Office WHO Heading AWIPS ID
GAYLORD, MI WHUS73 KAPX MWWAPX
DETROIT, MI WHUS73 KDTX MWWDTX
GRAND RAPIDS, MI WHUS73 KGRR MWWGRR
MARQUETTE, MI WHUS73 KMQT MWWMQT
CHICAGO, IL WHUS73 KLOT MWWLOT
NORTHERN INDIANA, IN WHUS73 KIWX MWWIWX
GREEN BAY, WI WHUS73 KGRB MWWGRB
MILWAUKEE, WI WHUS73 KMKX MWWMKX
DULUTH, MN WHUS73 KDLH MWWDLH

 

NWS Southern Region
Local Office WHO Heading AWIPS ID
MOBILE, AL WHUS74 KMOB MWWMOB
KEY WEST, FL WHUS72 KKEY MWWKEY
JACKSONVILLE, FL WHUS72 KJAX MWWJAX
MIAMI, FL WHUS72 KMFL MWWMFL
MELBOURNE, FL WHUS72 KMLB MWWMLB
TAMPA, FL WHUS72 KTBW MWWTBW
TALLAHASSEE, FL WHUS72 KTAE MWWTAE
LAKE CHARLES, LA WHUS74 KLCH MWWLCH
NEW ORLEANS, LA WHUS74 KLIX MWWLIX
BROWNSVILLE, TX WHUS74 KBRO MWWBRO
CORPUS CHRISTI, TX WHUS74 KCRP MWWCRP
HOUSTON, TX WHUS74 KHGX MWWHGX
SAN JUAN, PR WHCA72 TJSJ MWWSJU
SAN JUAN, PR/SPANISH/ WHCA72 TJSJ MWWSPN

 

NWS Western Region
Local Office WMO Heading AWIPS ID
LOS ANGELES, CA WHUS76 KLOX MWWLOX
SAN DIEGO, CA WHUS76 KSGX MWWSGX
MEDFORD, OR WHUS76 KMFR MWWMFR
PORTLAND, OR WHUS76 KPQR MWWPQR
SEATTLE, WA WHUS76 KSEW MWWSEW
EUREKA, CA WHUS76 KEKA MWWEKA
MONTEREY, CA WHUS76 KMTR MWWMTR

 

NWS Pacific Region
Local Office WMO Heading AWIPS ID
HONOLULU, HI WHHW70 PHFO MWWHFO
GUAM, GU WHGM70 PGUM MWWGUM

 

MWW Example
WHUS72 KMLB 281406
MWWMLB

URGENT - MARINE WEATHER MESSAGE
National Weather Service Melbourne FL
1006 AM EDT Thu Mar 28 2019

AMZ552-555-570-572-575-290900-
/O.EXP.KMLB.GL.W.0005.000000T0000Z-190328T1400Z/
/O.CON.KMLB.SC.Y.0017.000000T0000Z-190329T2000Z/
Volusia-Brevard County Line to Sebastian Inlet 0-20 nm-
Sebastian Inlet to Jupiter Inlet 0-20 
nm-Flagler Beach to Volusia-
Brevard County Line 20-60 nm
-Volusia-Brevard County Line to Sebastian Inlet 20-60 nm-
Sebastian Inlet to Jupiter Inlet 20-60 nm-
1006 AM EDT Thu Mar 28 2019

...SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 4 PM EDT FRIDAY...

* WINDS...Northeast winds 20 to 30 knots with occasional gusts to gale force this morning. 
Northeast winds decreasing to 20 to 25 knots this afternoon and evening.
 
* WAVES/SEAS...9 to 12 feet nearshore. Up to 12 to 16 feet offshore and near the Gulf Stream. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 20 to 33 knots are expected to produce 
hazardous wave conditions to small craft. Inexperienced mariners...especially those operating 
smaller vessels should avoid navigating in these conditions.

&&

$$
	

If you have additional questions on the MWW product, contact:

Darren Wright
National Weather Service
Marine Weather Program Leader
Phone: 301-427-9283
email: Darren.Wright@noaa.gov