Month of June Weather Review

The month of June was characterized by warmer and drier weather across most of the United States. This was as a result of high pressure that set up across the west and central United States during the middle part of the month and allowed the West to have above normal temperatures and be drier than normal during the month of June as a whole. (See previous blog post) At the same time that there was a high pressure system over the west and central United States, the eastern United States had a low pressure system because of the atmosphere’s wavelike pattern. Air flows around the high pressure in a clockwise manner and in a counter clockwise manner around low pressure systems. Consequently, air flowed from southwest to northeast from the western United States into south-central Canada and then northwest to southeast into the Mid-Atlantic States. The average low pressure over the northeast United States during the month of June allowed for near normal temperatures, but the low level dry air as a result of a June averaged northwest cool and dry flow contributed to morning cool temperatures and daily warm temperatures. Subsequently, that allowed what could have been above normal temperatures during the day to be offset slightly by the cool morning temperatures.

June averaged streamfunction indicating locations of high (low) pressure systems in red (blue). Notice the high pressure over the West and the low pressure over the East.
June averaged streamfunction indicating locations of high (low) pressure systems in red (blue). Notice the high pressure over the West and the low pressure over the East.
June's temperature anomalies. Notice the Warm temperature anomalies in the West and the near normal temperatures in the Northeast
June’s temperature anomalies. Notice the Warm temperature anomalies in the West and the near normal temperatures in the Northeast
Dry weather across the bulk of the United States.
Dry weather across the bulk of the United States shown by relative humidity departures from normal.
Boston's temperatures compared to normal. Notice the bottoms of the temperature ranges (the vertical blue columns) reaching in the minimum colorations. This was helped along by the drier weather.
Boston’s temperatures compared to normal. Notice the bottoms of the temperature ranges (the vertical blue columns) reaching in the minimum colorations. This was helped along by the drier weather.

 

With the low level dry air, the Northeast United States was also quite dry during the month of June with the only day above 1/4 inch of rain being June 4th to June 5th. That was when a low pressure system passed by to the northwest and dragged its warm front across the region with plenty of moisture associated with it. From then on through June the only precipitation was from thunderstorm activity, which tended to be hit or miss and quite light. As a result, the month of June for the northeast United States contained below normal precipitation and the drought increased in the northeast United States during June.

Precipitation anomalies for the month of June. Notice the above normal precipitation from the Northern Plains to the Mid-Atlantic. This was a flooding storm system. Also notice the below normal precipitation in the Southwest, north-central Plains and Northeast.
Precipitation anomalies for the month of June. Notice the above normal precipitation from the Northern Plains to the Mid-Atlantic. This was a flooding storm system. Also notice the below normal precipitation in the Southwest, north-central Plains and Northeast.
Boston's precipitation during June. Notice the early average rainfall with a day of around an inch of precipitation, but then the drop-off for the rest of the month.
Boston’s precipitation during June. Notice the early average rainfall with a day of around an inch of precipitation, but then the drop-off for the rest of the month.
Drought affects as a result of precipitation in the United States. Notice the increase of drought in the Northeast, Southeast and North Central US.
Drought affects as a result of precipitation in the United States. Notice the increase of drought in the Northeast, Southeast and North Central US.

 

While the Northeast United States and West were dry, the aforementioned general flow from northwest in south-central Canada to southeast into the Mid-Atlantic allowed an energetic disturbance to form and move along that track, as was also hinted at in the aforementioned previous blog post. Multiple areas of thunderstorms were able to form along it and training thunderstorms or storms that go over the same area multiple times contributed to record flooding rainfall in West Virginia from June 23rd to 24th. Southwest Virginia recorded 10+ inches of precipitation on June 24th with 1 to 1.5 inches of rain on the 23rd.  Unfortunately 26 fatalities occurred as a result of the flooding making it the third-deadliest flood in the state. In Queen Shoals, West Virginia, a river rose to 33.37 feet breaking a record from 1888 according to the National Weather Service (Via USA Today).

 

Back to top