Summerlike Warmth Returns for First Days of June

I'm expecting summerlike warmth to come back for the first week or so of June.

The image above shows projected 500mb height anomalies over the northern hemisphere. 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. In the image above, if we look towards the Bering Sea, we can see a very strong ridge of high pressure, seen by the splotch of red around the Aleutian Islands. This image is valid for May 13-14, and if we extrapolate it out 2-3 weeks using the Bering Sea Rule, we can expect high pressure and warm weather to appear in the East US.

If we look at another 500mb height anomaly forecast graphic, this one valid on May 19th, we now see that our strong ridge has shifted west into the middle of the Bering Sea, with cooler, stormier weather now protruding into western Alaska. This tells us that we can expect warm temperatures in the first several days of June in the middle of the country, with cooler conditions along the Eastern Seaboard.

This warmth is supported by long range modelling of enhanced tropical convection around the central Pacific, which is typically associated with warmer than normal weather in the Central and East US in the May-June-July time period. The bottom panel in the graphic above demonstrates the enhanced convection (blue) present in the Central Pacific.

Andrew

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