Severe Tropical Storm Mun (04W) - Tropical Cyclone Advisory #11, 1500 UTC 7/6/25

…Mun expected to become post-tropical by Tuesday…

Current storm information:

• Position: 33.3°N 149.6°E

• Movement: NNE at 6 knots (10 km/h)

• Intensity: 50 knots (95 km/h)

• Central pressure: 985 hPa

Trend:

• Mun is forecast to begin weakening later tonight, and it will likely become a post-tropical cyclone late Monday night or early Tuesday.

Watches and warnings:

• There are no land-based watches or warnings in effect.

Hazards affecting land:

• None.

Discussion:

Mun is beginning to lose tropical characteristics. The system has taken on an asymmetric appearance with most of its associated convection displaced to the south and east of an increasingly exposed circulation center. Convection has tried to wrap around the center intermittently, and an eye has been present every now and then, but the shear has consistently broken down the eyewall structure. Cloud tops within the single band of convection have also been warming for the past 12 hours or so. The intensity is 50 kts, which may be generous as most Dvorak-based and automated estimates are lower.

Mun is embedded within an upper-level trough, and this has resulted in a rather slow and erratic northward motion during the past couple of days. This motion is expected to continue for another day or so, with Mun expected to gradually turn northeastward as it gets swept up into the mid-latitude westerlies. Steadily cooling SSTs and even stronger shear will likely make quick work of Mun’s convection, and Mun will likely become a post-tropical cyclone late Monday or early Tuesday. The post-tropical cyclone should continue weakening as it accelerates to the east-northeast, and Mun will likely be absorbed by another extratropical low southwest of the Aleutian Islands by midweek.

Forecast positions and maximum winds

• 00 hrs: 33.3°N 149.6°E – 50 kts

• 12 hrs: 35.1°N 149.0°E – 40 kts

• 24 hrs: 37.1°N 148.4°E – 35 kts Post-tropical

• 48 hrs: 41.4°N 151.5°E – 35 kts Post-tropical/extratropical

• 72 hrs: 43.4°N 161.5°E – 30 kts Post-tropical/extratropical

• 96 hrs: Absorbed by larger extratropical low