Friday, June 21, 2013

Long Range Risk Analysis - June 21, 2013

This Long Range Risk Analysis covers the timeframe from now to the next 20 days. Confidence in this analysis is Average.

Overall Synopsis
Closed low in the Pacific Northwest will be torn up and allow the pattern to become mainly zonal for a prolonged period of time. The jet stream will be displaced into Canada and not only allow for increased heat, but lower chances of significant severe weather.

Severe Weather Outlook: Medium Activity
Confidence: Average
Multiple days of severe weather are expected in the short term as the Storm Prediction Center has outlined the Northern Plains for severe weather potential. This potential will eventually die down and shift a bit further north as the zonal atmospheric flow disrupts chances at significant severe weather. To account for the short term, the activity outlook is Medium with Average confidence.

Heat Outlook: High Activity
Confidence: Above Average
Zonal flow in the medium range will permit large high pressure formation over much of the nation (save the New England area) and induce warmer temperatures for days and days on end. The core of the heat is expected in the western Plains, with hot weather still expected as far east as the Mid-Atlantic. Details on the high pressure evolution remain a bit murky, but medium-range confidence allows an Above Average confidence level of High activity.

Tropical Outlook: Medium/High Activity
Confidence: Above Average
Short term has no interest in tropical development, although from June 30th we will begin to see increased activity. Very favorable upper and mid level atmospheric pattern will allow the development of at least one tropical cyclone. Depending on the longevity of the favorable upper air pattern, multiple tropical cyclones may be observed. Confidence in development chance is high, although formation and sustainment outlook is murky. Above Average confidence on a Medium/High Activity call is favored.