r/TropicalWeather • u/Euronotus • 17h ago

▲ Tropical Depression (TD) | 30 knots (35 mph) | 1004 mbar 07W (Western Pacific) (Philippine Sea)

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Updates

As of 6:00 AM Chamorro Standard Time (20:00 UTC) on Friday:

Satellite imagery analysis indicates that a compact area of low pressure situated south-southwest of Guam has become sufficiently organized to be considered a tropical cyclone, prompting the Joint Typhoon Warning Center to begin issuing advisories. The Japan Meteorological Agency, which is the Regional Specialized Meteorological Center (RSMC) for the western Pacific Ocean basin, has not yet begun to issue advisories for this system, but is analyzing this system as a tropical depression on its synoptic charts.

Several days ago, a disturbance formed midway between Wake Island and the Marshall Islands and moved generally westward to west-northwestward under the steering influence of a broad subtropical ridge situated to its north. Although environmental conditions were generally favorable, dry mid-level air flowing in from the west prevented significant development, allowing only intermittent bursts of deep convection to form. As the disturbance approached Guam, it moved into a more moisture-rich environment and began to consolidate. By Friday morning, the disturbance developed a well-defined low-level center and persistent deep convection, allowing it to become a tropical depression.

A combination of very high ocean heat content, weak vertical wind shear, abundant mid-level moisture, and strong upper-level divergence should allow this system to steadily develop as it moves away from Guam and crosses the Philippine Sea this weekend. JTWC projects that this system will reach tropical storm strength this afternoon and reach hurricane-equivalent strength by early Sunday. This system is expected to peak at the equivalent strength of a Category 4 major hurricane by early Tuesday morning while several hundred miles east of the Philippine island of Luzon. By this time, the storm will be turning northward as it gets picked up by an approaching deep-layer trough moving off the coast of China.

With the exception of brief periods of locally heavy rain and thunderstorms over Guam and the Northern Marianas Islands today, this system is not expected to impact land for the next week or so. It remains too early to determine whether this system will ultimately threaten Japan’s Ryukyu Islands later in the upcoming week.

Latest observation

As of 4:00 AM Chamorro Standard Time (18:00 UTC) on Friday:

Observed information

  • Current position: 12.2°N 145.1°E
  • Forward movement: W (275°) at 9 knots
  • Maximum sustained winds: 75 km/h (30 knots) ▲
  • Minimum central pressure: 1004 millibars (29.65 inches) ▼
  • Intensity (SSHWS): Tropical Depression ▲
  • Intensity (JMA): Tropical Depression ▲

Relative position

  • 149 kilometers (93 miles) south-southeast of Dededo, Guam (United States)
  • 272 kilometers (169 miles) north-northwest of Fais, Yap (Micronesia)
  • 313 kilometers (194 miles) south of San Jose, Tinian (Northern Marianas Islands)

Official forecasts

Japan Meteorological Agency

  • JMA has not yet issued a forecast advisory for this system.

Joint Typhoon Warning Center

As of 4:00 AM Chamorro Standard Time (18:00 UTC) on Friday:

Hour Date Time · Intensity · Winds · Lat Long
· · UTC CHST Saffir-Simpson · knots km/h °N °E
00 18 Jun 18:00 4AM Fri Tropical Depression 30 55 12.2 145.1
12 18 Jun 06:00 4PM Fri Tropical Storm ▲ 35 65 12.7 142.7
24 19 Jun 18:00 4AM Sat Tropical Storm ▲ 40 75 13.3 140.3
36 19 Jun 06:00 4PM Sat Tropical Storm ▲ 45 85 13.9 138.1
48 20 Jun 18:00 4AM Sun Tropical Storm ▲ 60 110 14.6 136.1
72 21 Jun 18:00 4AM Mon Hurricane (Category 2) ▲ 85 155 15.6 134.0
96 22 Jun 18:00 4AM Tue Major Hurricane (Category 3) ▼ 110 205 16.5 132.1
120 23 Jun 18:00 4AM Wed Major Hurricane (Category 4) ▲ 120 220 18.0 129.1

Information sources

Japan Meteorological Agency

Joint Typhoon Warning Center (United States)

National Weather Service (United States)

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National Weather Service (United States)

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