4 Things to Know About This Week's Weather

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Noticeable changes are expected across the U.S. for the first full week of May.

May began with summerlike heat in the Northeast, a rash of severe thunderstorms from the Plains into the Midwest and Northeast, while snow and cool temperatures prevailed in the West.

The jet stream pattern has now switched from a northward bulge over the East and a southward dip over the West to a broad southward dip over the East and a northward bulge in the West. This configuration of the jet stream persisted for much of April, but it will not be as pronounced in the week ahead as it was then. This general pattern will hold until late in the week or this weekend.

(MORE: What to Watch Out For and Look Forward to in May)

Below, we take a look at four things to know about the weather this week.

1. Much Less Widespread Severe Weather

A slow-moving low-pressure system brought rounds of severe thunderstorms from portions of the central U.S. into the Northeast last week.

This week's weather pattern will not favor a repeat of widespread severe weather.

(MORE: One of the Most Tornadic Times of Year Won't Have Many Tornadoes)

An area of low pressure will track through the Plains early this week. This system will continue eastward into the Midwest and Northeast late-week.

Ingredients for severe storms, including moisture, will be more limited with this system compared to last week. That said, a few severe storms could develop Wednesday in the mid-Mississippi and Lower Ohio valleys.

Another weather system will ride from the northern Rockies into the Midwest mid- to late-week with rain from Montana to the Great Lakes. We'll have more on this system's impacts below.

2. Heat Continues in the West

On Sunday, Phoenix (106 degrees) soared to a daily record high, and both Death Valley and Thermal, California, set the nation's first 110-degree highs of 2018.

Much of the southwestern U.S. will remain under the influence of an upper-level ridge of high pressure through at least the middle of the week. This will keep more summerlike temperatures in play over the Southwest and, at least through early this week, over the Rockies and Northwest.

(MORE: Snow Blanketed Parts of West To Start May)

Phoenix should see temperatures above the 100-degree mark through Friday.

Early this week, highs should climb into the mid- to upper 70s as far north as Portland, Oregon, with 70s also expected in Seattle.

Low temperatures for much of the West will also be warmer than average.

3. More Like Spring in the East

Last week, temperatures soared into the 90s as far north as parts of New England, making it feel more like summer. A cold front has since moved through, which has allowed temperatures to cool closer to what is expected in mid-spring.

High temperatures will remain near to warmer than average in the East through Thursday, after which a cold front may drape southward into parts of New England and New York state.

Expect highs to range from the 60s and 70s in New England to near 80 degrees closer to the Mason-Dixon line in the mid-Atlantic states. 

(MAPS: 10-Day Forecast)

4. Chillier, Wetter Weekend Ahead

Late this week, the pattern will change again.

Namely, a southward dip in the jet stream will lumber into the Rockies Friday, eventually pivoting into the Plains by the weekend.

With a frontal system draped across the Plains and upper Midwest, the setup for multiple rounds of thunderstorms with locally heavy rain will set in as soon as Thursday evening in this general zone.

(MAPS: Weekly Planner)

All that rain and cloud cover north of the frontal boundary will keep temperatures much chillier than recent days from northern New England to parts of the Great Lakes, northern Plains and northern Rockies, where highs may only manage the 50s late this week. A few of the colder locations in the northern Great Lakes and High Plains may struggle to get out of the 40s.

Temperatures may even be cold enough for snow over the higher elevations of the northern and central Rockies, as far south as the high country of Colorado to the west of Denver. 

(MAPS: 10-Day U.S. Forecast Highs and Lows)

It remains to be seen how much rain will be able to soak the exceptional drought area in the southern High Plains.