Truth Strikes: Debunking Biggest Weather Myths

A change in weather pattern this weekend will bring an end to the multi-day threat of severe thunderstorms as the East cools down and the Southwest heats up.

(MORE: Severe Weather Threat in Plains, Midwest)

The jet stream will reconfigure itself into a broad southward dip over the eastern states, with a large northward bulge developing across the West. This is a familiar pattern that dominated the United States for much of April.

Temperatures will return to closer to average across much of the East beneath that jet stream dip following the first prolonged warm spell of the spring for the Midwest and Northeast. The opposite will occur in the Southwest, where temperatures will warm to well-above-average levels this weekend into next week.

(MORE: As Midwest, East Warmed Up, Snow Blanketed Parts of West)

Widespread severe weather is uncommon in this type of setup because disturbances are unable to punch out of the Rockies and into the Plains, and any deep moisture is trapped near the Gulf Coast.

Given it's May, this pattern change won't usher in cold temperatures to the eastern states since average temperatures are mild this time of year. However, it will be a noticeable change after the widespread highs in the 70s, 80s and even 90s this week as far north as southern Canada.

New York City (92 degrees), Philadelphia (91 degrees) and Baltimore (92 degrees) all set new daily record highs on Thursday. Boston and Washington D.C. both reached 90 degrees Thursday but came up short of their records for the date.

Several cities broke or tied records again on Friday, including Baltimore (91 degrees), Georgetown, Delaware (90 degrees) and Erie, Pennsylvania (88 degrees).

(MORE: When the Last Freeze of the Season Typically Occurs)

Temperatures should still top out in the 60s or 70s for many locations this weekend into next week, as highs return to near average. This is certainly better than the record-cold and snowy April in parts of the Midwest and Northeast.

Meanwhile, the Southwest will bake in summerlike heat. Las Vegas will likely be in the upper 90s to near 100 degrees beginning Sunday and lasting through next week. The average high there is only in the mid-80s in early May.

Phoenix could see an extended stretch of days above 100 degrees beginning Saturday, which is 10 to 15 degrees above its average high of around 90 this time of year. The National Weather Service has issued an excessive heat warning for Phoenix on Sunday.

A few record highs are possible over the next few days, including Phoenix and Yuma on Sunday where current record highs are 105 and 107 degrees, respectively.

The southern Rockies, portions of the southern High Plains, as well as the Great Basin and Northwest, will also be well above average starting this weekend.

(MORE: May Temperature Outlook)

The good news about this upcoming pattern change is that any severe weather threats will be minimal, as the necessary ingredients for severe storms are not expected to be in place.