Atmospheric River Bringing Heavy Rain to Southern California and Heavy Snow to the Sierra Nevadas

A strong atmospheric river will continue heavy rain over southern California through Friday. The heaviest rainfall is ongoing today in the Los Angeles Basin. Flash and urban flooding is possible. A prolonged heavy snowfall has begun over the Sierra Nevada Mountains and will continue through Friday. Travel will become increasingly difficult over the passes due to snow and strong winds. Read More >

Anytime a tropical cyclone (TC) is in the WFO Guam Area of Responsibility, WFO Guam issues increasing
information regarding the TC(s). At a minimum, Public Advisories are issued every 6 hours, but as TC
watches/warnings are issued for islands (lead times of 48hr/24hr of the arrival of damaging winds (39 mph / 34
kt)), Public Advisories increase to every 3 hours, as well as the 6-hourly issuance of the Local Statements. More
information about our special TC text products is below, as well as a 12-hour clock cycle of our TC operational
schedule.

Public Advisory (TCPPQ#)

A plain-language interpretation of the JTWC warning bulletin.
Provides latest information on tropical storm/typhoon watches and warnings.
Issued at least every 6 hours when a tropical cyclone is expected to affect WFO Guam's Area of Responsibility.
Issued every 3 hours when TC watches or warnings are in effect for any of WFO Guam’s 39 TC
warning points.

Local Statement (HLSPQ#)

Specific forecast for each island under a watch or warning, including rain, wind, surf, storm surge and coastal inundation, as well as recommended preparations.

Tropical Cyclone Update (TCUPQ#)

Hourly radar-based position estimates of a TC when within the range (about 230 miles) of Guam's Doppler radar.
Issued hourly near the top of the hour when a center position fix is available.
May also be issued, at any time, for significant changes, notable observations, or notable events
occurring in the development or progress of a TC in the Marianas.

Post-Storm Tropical Cyclone Reports (PSHGUM)

Brief history of a TC requiring WFO Guam’s issuance of TC watches/warnings.
Observational data from islands or surrounding marine zones during the TC passage.
Impacts narratives from each island affected by a passing TC.