=== Is there an historical analog? === In 1956, Colorado experienced a dry spring and a hot June. This was also a La Niña year as was the case in 2012 until late spring. The maps below compare the patterns of 1956 to those in 2012. These maps show a similar story in terms of circulation patterns and their effects. ==== Temperature ==== {{gallery popup="true" entries="ee127951-7747-43ea-8a9b-3f729e640520,ef987b46-61f3-4e62-9159-e2c7a717ae1f" width="300" }} ==== Precipitation ==== {{gallery popup="true" entries="d7899c55-6225-4eff-a408-2f51c4a9b031,2f4c29f6-ca88-4181-ac0a-b9908bf75bcd" width="300" }} ==== 500 millibar heights (May-June) ==== {{gallery popup="true" entries="6529d9af-5de4-424e-b212-9d865b48f3e6,935eb80f-d30b-4c72-aa83-aa63875adf21" width="300" }} <!-- Addressing the patterns associated with the June 1956 heatwave in an article (McQueen and Shellum, 1956) in the Monthly weather, McQueen and Shellum stated: "It might be well to state that while it is practically essential that the 700-mb. and 500-mb. height be above normal for the formation of a heat wave condition, this fact by itself is not sufficient in the development of an above normal temperature area. The air mass must approach the dry-adiabatic and not be of a stable air mass type. Little or no moisture should be indicated by the upper-air soundings as the sky must be practically cloudless. In addition, there should be a high probability of these conditions being or becoming stagnant over the area." -->