US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
405 PM EDT Mon Jun 29 2020
 
Valid Thursday July 02 2020 - Monday July 06 2020
 
Hazards:
- Flooding possible across portions of the Upper/Middle Mississippi Valley, the Great Lakes, and 
the Northern Plains.
- Flooding occurring or imminent across portions of the Central Plains, the Upper/Middle 
Mississippi Valley, and the Northern Plains.
- Flooding likely across portions of the Northern Rockies.
- Excessive heat across portions of the Central Plains, the Lower Mississippi Valley, the Tennessee 
Valley, the Middle Mississippi Valley, the Southeast, and the Southern Plains, Thu-Fri, Jul 2-Jul 3.
- Much above normal temperatures across portions of the Great Lakes, the Upper Mississippi Valley, 
and the Northern Plains, Thu-Sun, Jul 2-Jul 5.
- Much above normal temperatures across portions of the Southwest, Sun-Mon, Jul 5-Jul 6.
 
Detailed Summary:

An unusually intense upper-level low over the Western U.S. will lift into Southwestern Canada by 
Thursday.

Upper-level ridging extending from the Southern Plains northeastward into the Upper Great Lakes 
will strengthen on Thursday into Monday.  Under the upper-level ridging temperatures will become 
much above normal temperatures (on the order of 12-15 degrees) across parts of the Northern Plains 
into parts of the Upper Great Lakes from Thursday into Monday.  Also under the upper-level ridge 
moisture from the Gulf of Mexico will pool over the Lower Mississippi Valley. This moisture will 
allow dewpoints to reach the mid to upper 70's and surface temperatures will range from the low 
90's to the mid 100's that will produce heat indexes from 110 to 115 degrees that will exceed the 
criteria for excessive heat over this part of the country which is 105 degrees or greater.  The 
excessive heat will last on Thursday into Friday.  

Elsewhere, as the aforementioned upper-level trough retreats into Canada, upper-level ridging will 
build over parts of Southeastern California into parts of Southern Nevada on Sunday into Monday.  
The ridging will allow surface temperatures to become 12 degrees above normal on Sunday into 
Tuesday, too.  Those temperatures will meet the criteria for much above normal temperatures for 
this region. 

No hazards are forecast over Alaska.

Ziegenfelder