May 21-25 Potential Storm System & Severe Weather

I'm analyzing the May 21-25 time period for a substantial storm system to bring cool weather and possibly some severe weather to the nation.

Tropical Tidbits

The image above shows projected 500mb height anomalies over the western Pacific. We can signify the blues with negative height anomalies, which indicate the presence of cooler and stormier weather, while reds denote positive height anomalies, which allow for warmer than normal and calm weather. Looking towards Japan on this forecast graphic, valid on May 15th, we see a substantial closed low approaching Japan, bringing in cooler than normal and unsettled weather for the area. If we utilize the Typhoon Rule, we can expect this storm system to impact the United States 6-10 days after this storm affects Japan, which would give us a May 21-25 time period.

Indications I am getting from this graphic tell me much of the United States may be impacted by this cooler than normal weather, and while I do believe severe weather is possible, I'm currently thinking any severe weather will be limited due to the lack of a powerful ridge advecting north over Japan prior to this closed low hitting the country.

Andrew