I am posting this thread as an educational resource for those interested in summertime climatology across the continental US.
In the summer the mid-latitude westerlies that help give rise to the severe weather we often see in the Plains April-June, migrates NWRD to the northern tier of states and sometimes into Canada. Across the south the westerlies are replaced by one or two dominant subtropical anticyclones, one in the SWRN US and/or another across the SERN US. The prevailing flow aloft is predominantly light easterlies across the southern tier of states. This is evidenced from this graphic below.
What you got to watch out for in the summer are embedded impulses ridding along the northern periphery of these subtropical ridges. These impulses can spark off some rather violent severe weather with the combination of ~40kts of shear and ~3000 CAPES. Meteorologist sometimes refer to this area along the edge of the subtropical ridge(s) as the "ring of fire". A good example of this comes from tomorrows (7/21) QPF forecast from the WRF-NMM.
South of this region of convection across the southern tier of states theres usually a lot of sinking air and very warm temperatures aloft beneath the ridge. This results in triple digit heat across parts of the Central and Southern Plains.
Across the inter-mountain west, the high sun angle heats up the dry-desert like surface below during the day resulting in a tremendous amount of rising thermals. This rising air is what results in the scattered afternoon and evening thunderstorms across this region in July and August. This is also referred to as the SW monsoon. These storms can be quite the lightning producers and have been known to spark some large wildfires that we sometimes hear about in the news this time of year. You can see the monsoon in the QPF graphic above.
In the summer the mid-latitude westerlies that help give rise to the severe weather we often see in the Plains April-June, migrates NWRD to the northern tier of states and sometimes into Canada. Across the south the westerlies are replaced by one or two dominant subtropical anticyclones, one in the SWRN US and/or another across the SERN US. The prevailing flow aloft is predominantly light easterlies across the southern tier of states. This is evidenced from this graphic below.
What you got to watch out for in the summer are embedded impulses ridding along the northern periphery of these subtropical ridges. These impulses can spark off some rather violent severe weather with the combination of ~40kts of shear and ~3000 CAPES. Meteorologist sometimes refer to this area along the edge of the subtropical ridge(s) as the "ring of fire". A good example of this comes from tomorrows (7/21) QPF forecast from the WRF-NMM.
South of this region of convection across the southern tier of states theres usually a lot of sinking air and very warm temperatures aloft beneath the ridge. This results in triple digit heat across parts of the Central and Southern Plains.
Across the inter-mountain west, the high sun angle heats up the dry-desert like surface below during the day resulting in a tremendous amount of rising thermals. This rising air is what results in the scattered afternoon and evening thunderstorms across this region in July and August. This is also referred to as the SW monsoon. These storms can be quite the lightning producers and have been known to spark some large wildfires that we sometimes hear about in the news this time of year. You can see the monsoon in the QPF graphic above.
