US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
359 PM EDT Thu May 21 2020
 
Valid Sunday May 24 2020 - Thursday May 28 2020
 
Hazards:
- Heavy rain across portions of the central and southern Plains, Sun-Mon, May 24-May 25.
- Heavy rain across portions of central and southern Plains, Tue-Wed, May 26-May 27.
- Flooding possible across portions of the interior Southeast into the interior Mid-Atlantic and 
the southern Appalachians.
- Flooding occurring or imminent across portions of the lower Mississippi Valley, northeastern 
South Dakota, the interior Pacific Northwest, the Midwest, lower Great Lakes, and the Ohio Valley.
- Flooding likely across portions of the Mid-Atlantic, the southern Appalachians, and the northern 
Rockies.
- Much above normal temperatures from portions of California into Nevada, Tue-Thu, May 26-May 28.
- Much above normal temperatures across portions of the central Great Basin into the central and 
southern Rockies, Wed-Thu, May 27-May 28.
- Heavy precipitation across portions of coastal southern Alaska, Sun, May 24.
 
Detailed Summary:

As the highly amplified upper-level pattern breaks down and returns to a more typical 
configuration, a cold front is forecast to push southward through the Great Plains and become a 
focus for heavy rain during the medium range period (Sunday 5/24 - Thursday 5/28).  Moisture 
returning from the Gulf of Mexico should begin to raise the threat of heavy rainfall from the 
central Plains southward into Texas well ahead of the cold front on Sunday.  From Memorial Day 
onward, the highest threat of heavy rain should shift farther south into Texas as the cold front 
begins to interact with an upper-level vortex which is forecast to detach from the northern stream 
and then lingers over the southern High Plains.

Cooler than normal conditions are expected to spread from the northwestern U.S. toward the southern 
Plains behind the cold front in contrast with above normal temperatures across the upper Midwest 
and the Great Lakes spreading toward the Northeast ahead of the front.  High temperatures could be 
well up into the 80s across the interior Northeast by midweek next week.  Meanwhile, a warming 
trend is expected to spread from west to east across the western U.S. starting on Memorial Day as 
an upper-level ridge builds over the Southwest.  Temperatures are expected to be well above normal 
for a good portion of California into Nevada Monday and Tuesday, spreading eastward into parts of 
the central and southern Rockies Wednesday and Thursday.

As for Alaska, heavy precipitation near the southern coastal sections of Alaska should gradually 
taper off on Sunday as the associated occluded cyclone continues to weaken.  Above normal 
temperatures are forecast to persist across central to northern Alaska but they do not necessitate 
a temperature hazardous area at this time.  However, ice jam flooding will be 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.

Kong