US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
334 PM EDT Tue May 04 2021
 
Valid Friday May 07 2021 - Tuesday May 11 2021
 
Hazards:
- Heavy rain across portions of the Central Plains, the Middle/Lower Mississippi Valley, the 
Tennessee Valley, the Great Lakes, the Southern Appalachians, the Southeast, the Southern Plains, 
and the Ohio Valley, Sat-Tue, May 8-May 11.
- Flooding occurring or imminent across portions of the Southern Plains.
- High winds across portions of California and the Pacific Northwest, Fri-Tue, May 7-May 11.
 
Detailed Summary:

n the medium-range forecast period, an area of strong high pressure over the Eastern Pacific †
off the West Coast of the CONUS †and a thermal trough developing over California will create a 
strong pressure gradient over California and along as well offshore from the California Coast.  
With high pressure being semi-permanent, the area of high wind will continue from Friday to 
Tuesday. 

Meanwhile, a developing area of low pressure over the Central High Plains will move eastward to the 
Western Ohio Valley on Sunday, pulling a front across the Mississippi Valley and the Plains.  On 
Monday, the low moves off the Northeast Coast with a trailing front from the Mid-Atlantic to the 
Southern Plains.  The front becomes quasi-stationary, extending from the southern 
Mid-Atlantic/Southeast to the Southern Plains.  Heavy rain will develop along the front over parts 
of the Ohio/Middle Mississippi Valleys on Saturday and moves southward with the front over the 
Lower Mississippi /Tennessee/Ohio Valleys by Sunday. When the boundary becomes quasi-stationary, 
the area of heavy rain will continue over the Lower Mississippi/Tennessee Valleys, the Southeast, 
and parts of the Southern Appalachians on Monday and Tuesday. 

For Alaska, an area of low pressure will move along the Aleutians on Friday, followed by another 
area of low pressure moving over the Aleutians on Saturday.  A third area of low pressure moves 
close to the Aleutians on Sunday and is slow to move away on Monday.  The areas of low pressures 
have a pressure gradient associated with them.  At this point in time, the wind associated with the 
lows over the state will be below the criteria for high wind. 

Ziegenfelder