97W upgraded to a Tropical Cyclone Formation Alert

A developing tropical disturbance, Invest 97W, was upgraded to “High” for development, or a Tropical Cyclone Formation Alert, this morning by the Joint Typhoon Warning Center. This means that 97W could be upgraded to a tropical depression within the next 24 hours. At 6am ChST, 97W was centered near 13.7N 144.2E, just west-northwest of Guam. 97W is expected to lift northward today with a gradual turn toward the northwest and away from the Marianas.

Monsoon surge

Invest 97W does not pose a direct threat to the Marianas or western Micronesia. However, the strong monsoon being influenced by 97W will surge from across Palau and Yap State, to Guam and the CNMI through tonight.

Winds will strengthen through the day as the surge increases across the region. The CNMI is already seeing strong wind gusts this morning with sustained winds at the Saipan airport of 20 to 30 mph and with gusts up to 45 to 50 mph. The Saipan airport just recorded a gust of 49 mph in their 9am observation. Across Guam, winds outside of showers have been pleasant, but with moderate to heavy showers, are reaching to between 15 and 20 mph sustained, with gusts up to 30 mph. Stronger winds prevail to the south and east, near a band of heavier showers. This will all shift northwestward over Guam and Rota later today.

Wind impacts will be similar to those last week: Tents, canopies, tarps, trash bins, lawn furniture and other loose, outdoor items will be vulnerable to the strong winds and gusts. We are anticipating peak conditions this afternoon across the Marianas with the strongest winds and heavy showers then. Conditions will improve by Tuesday morning with better conditions across the region for the last half of the week.

Watches/warnings /advisories

• A number of watches, warnings and advisories are in effect due to wind, rain and marine-based hazards.
• High Wind Warning – Guam/CNMI – through 6am Tuesday
• High Surf Advisory – Guam/CNMI – through 6pm Tuesday
• Flood Watch – Guam/CNMI – through 6am Tuesday
• Gale Warning – Guam/CNMI – through 6am Tuesday

• Hazardous Seas Warning – Guam/CNMI – through 6am Tuesday

• High Surf Advisory – Yap – through 6pm Monday (this evening)
• Small Craft Advisory – Yap – through 6pm Tuesday
• Small Craft Advisory – Palau – through 8am Tuesday

Please stay up to date with the latest forecasts and information from the NWS Guam on the web at www.weather.gov/gum. (PR)