US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
344 PM EDT Thu Jun 18 2020
 
Valid Sunday June 21 2020 - Thursday June 25 2020
 
Hazards:
- Heavy rain across portions of the Central/Southern Plains, the Middle Mississippi Valley, the 
Lower Mississippi Valley, and the Tennessee Valley, Sun-Wed, Jun 21-Jun 24.
- Heavy rain across portions of the Southern Plains, Tue-Thu, Jun 23-Jun 25.
- Flooding possible across portions of the Northern Plains.
- Flooding occurring or imminent across portions of the Middle Mississippi Valley, the 
Mid-Atlantic, and the Northern Plains.
- Flooding likely across portions of the Mid-Atlantic and the Northern Rockies.
- Much above normal temperatures across portions of the Central Great Basin, California, and the 
Northern Great Basin, Tue-Thu, Jun 23-Jun 25.
- Much above normal temperatures across portions of the Northeast, Sun-Tue, Jun 21-Jun 23.
 
Detailed Summary:

An upper-level ridging ahead of an upper-level trough over the Upper Mississippi Valley will build 
into parts of the Northeast as an upper-level low over the Mid-Atlantic slowly weakens on Sunday.  
The building upper-level ridging will allow temperatures to become 12 degrees above normal over the 
Northeast on Sunday.  On Sunday the upper-level trough over the Upper Mississippi Valley will begin 
to move into the Northeast. These conditions meet the criteria for depicting and area of much above 
normal temperatures over the region on Sunday into Monday.  After Monday the upper-level trough 
will move over the Northeast making the temperatures cooler than the criteria. 

Upper-level ridging over the Pacific will move onshore over the Pacific Northwest overnight Monday. 
 The ridging will remain over the area and additional ridging will move onshore on Thursday.  The 
ridging over the area will allow temperature to become 12 degrees above normal that will reach the 
criteria for much above normal temperatures over a relatively small area over parts of the Pacific 
Northwest and Northern California from Tuesday into Thursday. 

A front extend from the Upper Great Lakes to the Southern High Plains and will move eastward to the 
Lower Great Lakes to the Central Plains will stalling over the area.  A plume of moisture will move 
northward from the Western Gulf of Mexico northward over the Southern Plains on Sunday into Monday 
that will overrun the front. Showers and thunderstorms and maybe a convective system will develop 
along the front that will produce enough rain to meet the criteria for heavy rain over parts of the 
Central/Southern Plains into parts of the Middle/Lower Mississippi Valley and parts of the 
Tennessee Valley on Sunday into Wednesday.  Meanwhile, upper-level energy over parts of the Western 
Gulf Coast and moisture flowing off the Gulf of Mexico will aid in producing heavy rain over the 
Western Gulf Coast in Texas on Tuesday into Thursday.

No hazards are delineated over Alaska. There will be rain over the Alaska Panhandle yet the rain 
will not meet the criteria for heavy rain over the area.

Ziegenfelder