Strong ridge to fuel near-record heat in the Southwest late this week

As we plow ahead toward monsoon season here in July, the monsoon will find it difficult to get started as a massive ridge in the jet stream closes the door to moisture from Mexico for the time being.

It has already been a hot few days in the Southwest, with Phoenix reaching 110 degrees the past few days.

There has been some troughiness in the West and Southwest recently, but a huge ridge will gradually build into the weekend.

Here is a look at the flow in the mid-levels of the atmosphere off the GFS valid on Saturday.

Without getting too deep in the weeds on what everything on this map means, take note of the "600" bubble over Arizona and New Mexico. That is a range we don't see a whole lot on these maps, so that is an indication of a very strong ridge.

The result will be high temperatures around or above 115 degrees this weekend in Phoenix and temperatures over 110 degrees in Las Vegas.

There will be a bump in temperature as far west as the California coast, but the increase will be small, especially when compared to offshore wind events.

The heat is not great news for what has been a rough fire season so far in Arizona, although the wind will not be a significant factor in this stretch of hot weather. That should prevent the fire concerns from reaching critical levels. However, as long as the heat and dry weather win out over the monsoon, the longer the fire season will drag on in the Desert Southwest.

There really aren't any signs that the monsoon will get going in any meaningful way in the next week or two.

The ridge will mostly be over the Southwest, and you need the ridge to be more to the east so the flow around the ridge can bring moisture, and in turn showers and thunderstorms, into the Southwest from northern Mexico.

There are some signs that the ridge may drift eastward toward the middle of the month, which would potentially allow the monsoon to get started.