US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
458 PM EDT Mon May 25 2020
 
Valid Thursday May 28 2020 - Monday June 01 2020
 
Hazards:
- Heavy rain across portions of California, the Pacific Northwest, and the Northern Great Basin, 
Sat-Mon, May 30-Jun 1.
- Heavy rain across portions of the Southeast and the Lower Mississippi Valley, Thu, May 28.
- Heavy rain across portions of the Northeast and the Great Lakes, Fri, May 29.
- Flooding possible across portions of the Southeast, the Mid-Atlantic, and the Ohio Valley.
- Flooding occurring or imminent across portions of the Middle/Lower Mississippi Valley, the 
Northern Plains, the Northern Rockies, the Mid-Atlantic, the Southern Appalachians, the Northern 
Great Basin, the Southeast, and the Great Lakes.
- Much above normal temperatures across portions of the Northern/Central Plains, the Central Great 
Basin, the Rockies, the Upper/Middle Mississippi Valley, California, the Northern Great Basin, the 
Pacific Northwest, and the Southwest, Thu-Mon, May 28-Jun 1.
- Much above normal temperatures across portions of the Northeast, Thu-Fri, May 28-May 29.
- Heavy rain across portions of mainland Alaska and the Aleutians, Mon, Jun 1.
- Much above normal temperatures across portions of mainland Alaska, Thu-Mon, May 28-Jun 1.
 
Detailed Summary:

Upper-level ridging over the Northeast on Thursday will slowly weaken as and upper-level low over 
the Southern Plains/Lower Mississippi Valley moves northeastward and a trough over the Canadian 
Prairies moves eastward to the Great Lakes by Saturday morning. The trough and the upper-level low 
will weaken the ridge over the Northeast, likewise by Saturday. The upper-level ridging will aid in 
producing much above normal temperatures over the Northeast on Thursday and Friday. 

Over the West Coast, another upper-level ridge over the Southwest/Great Basin will expand eastward 
as the aforementioned upper-level low and trough move eastward.  This will allow temperatures to 
increase over the West Coast and slowly move eastward to the Upper Midwest by Monday 01 June. The 
temperatures will be warm enough to meet the criteria for much above normal temperatures that will 
similarly move eastward to Northern/Central Plains and the Upper Mississippi Valley on Thursday 
through Monday.  Furthermore, another upper-level low over the Eastern Pacific will move 
northeastward to Northern California by Sunday followed by another region of upper-level energy 
moving over the location on Monday.  These two regions of energy will aid in producing an inch or 
more of rainfall on Sunday and Monday over Oregon.        

Over Alaska, above normal temperatures are forecast to persist across the North Slope of Alaska 
with a upper-level high over the region from Thursday to Monday.  Ice jam flooding will be remain a 
concern over the North Slope as rivers have not yet broken up, while minor snowmelt flooding is a 
possibility in central and southern parts of the mainland.  Meanwhile, a developing deep surface 
low over the North Pacific will move just south of the Aleutian Islands on Sunday and lingering 
through to Monday.  The Low will produce heavy rain over the Eastern Aleutians and the Alaska 
Peninsula on Monday.

Ziegenfelder