US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
312 PM EDT Wed Jun 09 2021
 
Valid Saturday June 12 2021 - Wednesday June 16 2021
 
Hazards:
- Flooding possible across portions of the Tennessee Valley.
- Flooding occurring or imminent across portions of the Lower Mississippi Valley and the Southern 
Plains.
- Excessive heat across portions of the Central Great Basin, California, and the Southwest, 
Sun-Wed, Jun 13-Jun 16.
- Excessive heat across portions of the Northern Plains and the Northern Rockies, Mon-Tue, Jun 
14-Jun 15.
- Much above normal temperatures across portions of the Central Plains, the Central Rockies, the 
Central Great Basin, the Northern Plains, the Northern Rockies, the Southern Rockies, the Northern 
Great Basin, the Upper Mississippi Valley, and the Southwest, Sun-Wed, Jun 13-Jun 16.
- Much above normal temperatures across portions of the Northern Rockies and the Northern Great 
Basin, Sun-Tue, Jun 13-Jun 15.
 
Detailed Summary:

The medium range forecast period (Saturday, June 12 to Wednesday, June 16) will feature a building 
upper-level ridge over the Rockies, High Plains, and Southwest, with upper-level troughs expected 
over the East and Pacific Northwest. As a result, this weather pattern is forecast to focus much of 
the precipitation along the East Coast, Southeast, and Gulf Coast. However, outside of local 
impacts from isolated downpours, no widespread heavy rain is expected during this time frame. 
Temperatures are expected to remain around average to slightly below average along the East Coast, 
Southeast, and Deep South as well.

The main weather story across the Lower 48 during the medium range period will be associated with 
excessive heat and much above average temperatures throughout the West and north-central United 
States. By this weekend, above average temperatures will begin to build across the Intermountain 
West, northern/central Rockies, and northern Plains. The sizzling heat will settle over this region 
due to an anomalously strong upper-level ridge/high pressure centered near the Four Corners region. 
There is high confidence within the global forecast guidance regarding this feature and associated 
weather pattern. The center of the highest temperature anomalies (15 to 20 degrees above average) 
are currently forecast over the northern Rockies and northern High Plains on Monday and Tuesday of 
next week. Widespread temperatures in the 90s are expected, with triple digits possible over 
central and eastern Montana. An excessive heat area was added to the hazards chart today to 
highlight the potential for temperatures to reach dangerously high levels throughout parts of 
Montana and northern Wyoming. This area of extreme heat may shift eastward and into the Dakotas and 
Minnesota by Wednesday, but large uncertainty exists here by the middle of next week regarding the 
magnitude of the above average temperatures. The Intermountain West will also see scorching heat 
beginning on Sunday and lingering through next week. Places such as Salt Lake City, Utah could 
experience multiple days with high temperatures close to 100 degrees. Parts of the northern Great 
Basin should see relief from the summer heat by Wednesday as a Pacific cold front sweeps through. 
Meanwhile, the Desert Southwest will also see its fair share of extreme heat, which will 
undoubtedly increase the already exceptional drought concerns over the region. With several 
consecutive days with high temperatures between 110 and 120 degrees possible by Sunday, residents 
are urged to plan on spending plenty of time indoors/out of the heat. High temperatures will 
possibly soar higher than 120 degrees throughout the typical desert valleys in the Southwest on 
Tuesday and Wednesday. Several daily high temperature records are forecast on Tuesday from 
southwest California and Arizona to Montana. 

For Alaska, a potent low pressure system over the Bering Sea may bring gusty winds to the Aleutian 
islands and heavy rain to southwest portions of the state along the Gulf of Alaska late this 
weekend into early next week. However, both of these potential hazards appear to remain below 
threshold.

Snell