Four Things To Look For This Week: Hot West, Mild East, Stormy Plains, Southwest Monsoon

Tom Moore
Published: June 27,2016

June can often feature a wide variety of weather, and this week will be true to form as we close out the month.
A widespread ridge (bulge in the jet stream) will allow much of the West to remain hot. Meanwhile, a trough (dip in the jet stream) will keep a good portion of the East quite mild for this time of year. Between the ridge and the trough, a "battleground" zone will set up, most likely in the Plains, where thunderstorms are likely to occur.
For the first time this season, it looks like some "monsoonal" moisture will sneak into parts of the southwestern U.S.
Let's take a deeper look at what we'll see this week.

Jet Stream With Western Heat (Red) vs. Eastern Cool (Yellow)

1.) Mild East

Areas from the Great Lakes to New England, down to the mid-Atlantic, have been able to dodge any persistent heat so far, and that trend will continue this week. A trough of low pressure (southward dip in the jet stream) has been a frequent visitor to these areas.
This pattern is favorable for frequent cold fronts to move through, and another one will move through this week. That front will likely produce scattered showers and thunderstorms from Monday through Wednesday, but severe weather is unlikely.
The result will be high temperatures around, or slightly below seasonal averages for a few days. Low temperatures in the 50s to low 60s will also be likely. Needless to say, most residents are hoping that this general pattern will last through the summer.

Mild Temperatures In The East This Week

2.) Western Heat Persists

The East has been mild in recent weeks, but the West has been a far different story. A ridge of high pressure (bulge in the jet stream) seems to have taken up residence throughout much of this region. This rather large ridge will hang tough through this week.
The result will be more hot temperatures for areas away from the immediate West Coast. The Great Basin could see temperatures eclipsing 100 degrees, and a daily record high will be threatened in Salt Lake City on Monday with temperatures rising above 100 degrees.
Reno, Nevada, could set new daily record highs on Tuesday and Wednesday, with temperatures climbing to around 100 degrees.
Some moisture is expected to make its way into the Southwest this week, which may allow temperatures to be a bit lower in cities like Phoenix, but humidity levels will be higher.
(MAPS: 10-Day Forecast)

West Remains Hot Through This Week

3.) Southwest Monsoon Arrives

When the core of high pressure aloft sets up across the Four Corners area, moisture can sneak into the Southwest. The "summer monsoon" often kicks in at the end of June or early July, and it looks like that pattern will set up this week. With dew points rising, humidity levels will be higher from parts of New Mexico back to Southern California.
There will be scattered thunderstorms, mainly in the higher terrain, early in the week, but some thunderstorms could find their way into lower elevations as the week progresses. Many of these thunderstorms have little rain, but can produce gusty winds and blowing dust.
(MORE: Weekly Planner)

"Monsoonal" Moisture Moves Into the Southwest This Week

4.) Stormy Plains

Between the western ridge and the eastern trough, we will likely have a "battleground" zone where thunderstorms are more likely to occur. For this week, scattered thunderstorms are expected in portions of the High Plains into midweek.
Some of these thunderstorms are likely to turn severe. The highest risk for severe thunderstorms on Monday and Tuesday will be found from northwestern Kansas, northeastern Colorado, western Nebraksa, western South Dakota and eastern Wyoming.
(MORE: Severe Thunderstorm, Heavy Rain in the Plains Forecast)
Thunderstorms in the Plains this time of year can often form a line of damaging winds, or they can cluster together to produce locally heavy rain. Both may be concerns this week and we will continue to monitor this system.
(FORECAST: Rapid City, South Dakota | North Platte, Nebraska | Omaha, Nebraska | Kansas City)

Monday's Thunderstorm Forecast

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