WHGM70 PGUM 201839

MWWGUM



URGENT - MARINE WEATHER MESSAGE

National Weather Service Tiyan GU

439 AM ChST Sat Mar 21 2026



PMZ153-154-210845-

/O.NEW.PGUM.SC.Y.0031.260320T1839Z-260322T0700Z/

Tinian Coastal Waters-Saipan Coastal Waters-

439 AM ChST Sat Mar 21 2026



...SMALL CRAFT ADVISORY IN EFFECT UNTIL 5 PM CHST SUNDAY...



* WHAT...Northeast winds 15 to 20 kt with gusts up to 30 kt and

  seas 8 to 10 feet.



* WHERE...Tinian and Saipan Coastal Waters.



* WHEN...Until 5 PM ChST Sunday.



* IMPACTS...Conditions will be hazardous to small craft.



* ADDITIONAL DETAILS...Elevated northeast to east swell and wind

  waves, reinforced by diminishing long-period north to northeast

  swell produced by distant low pressure systems, will produce seas

  up to 10 feet within the eastern Marianas coastal waters. The

  increase in seas will initially occur over eastern Saipan and

  Tinian waters before spreading to Guam and Rota waters tonight,

  producing to conditions hazardous to small craft. Combined seas may

  briefly diminish around Sunday night, increasing once more through

  Monday as the northeast swell and wind waves are reinforced by a

  building trade-wind surge. This may lead to a reissuance or 

  extension of hazards.



PRECAUTIONARY/PREPAREDNESS ACTIONS...



Inexperienced mariners, especially those operating smaller

vessels, should avoid boating in hazardous conditions.



&&



$$



PMZ151-152-210845-

/O.NEW.PGUM.SC.Y.0031.260321T1200Z-260322T0700Z/

Guam Coastal Waters-Rota Coastal Waters-

439 AM ChST Sat Mar 21 2026



...SMALL CRAFT ADVISORY IN EFFECT FROM 10 PM THIS EVENING TO 5 PM

CHST SUNDAY...



* WHAT...Northeast winds around 20 kt with gusts up to 30 kt and seas

  7 to 10 feet expected.



* WHERE...Guam and Rota Coastal Waters.



* WHEN...From 10 PM this evening to 5 PM ChST Sunday.



* IMPACTS...Conditions will be hazardous to small craft.



* ADDITIONAL DETAILS...Elevated northeast to east swell and wind

  waves, reinforced by diminishing long-period north to northeast

  swell produced by distant low pressure systems, will produce seas

  up to 10 feet within the eastern Marianas coastal waters. The

  increase in seas will initially occur over eastern Saipan and

  Tinian waters before spreading to Guam and Rota waters tonight,

  producing conditions hazardous to small craft. Combined seas may

  briefly diminish around Sunday night, increasing once more through

  Monday as the northeast swell and wind waves are reinforced by a

  building trade-wind surge. This may lead to a reissuance or 

  extension of hazards.



PRECAUTIONARY/PREPAREDNESS ACTIONS...



Inexperienced mariners, especially those operating smaller

vessels, should avoid boating in hazardous conditions.



&&



$$



DeCou