An interesting weather event is forecast to evolve in the northeastern Pacific over the next 24-48 hours. The remnants of Tropical Storm Namtheun are in the process of converting into an extratropical storm system in the northern Pacific. This process will continue on Wednesday and Thursday and the system will rapidly deepen and intensify.

The system will intensify so much that the central pressure is forecast to drop to 950 mb or lower. This is a greater than 48 mb drop in barometric pressure in a short period of time. Because of such a quick drop in pressure during the intensifcation process, this system will become what is known as a superbomb cyclone late Wednesday. This occurs when a storm system observes a drop in pressure of at least 48 mb within a 24 hour period.

![](https://firsthandweather.s3.amazonaws.com/9_km_ECMWF_Global_Pressure_850_h_Pa_Wind_850_h_Pa_Wind_48_25452816c1.png)

European 850 hPa Wind Speeds in knots (WeatherModels.com)

![](https://firsthandweather.s3.amazonaws.com/9_km_ECMWF_Global_Pressure_500_h_Pa_Height_500_h_Pa_Height_42_2b9d29975a.png)

European 500hPa Geopotential Height (WeatherModels.com)

This storm is forecast to bring impacts to parts of British Columbia and Alaska late this week.

large_9-km-ECMWF-Global-Pressure-850-hPa-Wind-850-hPa-Wind-48.png

“Superbomb” storm in northeast Pacific