US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
431 PM EDT Thu Sep 24 2020
 
Valid Sunday September 27 2020 - Thursday October 01 2020
 
Hazards:
- Heavy rain across portions of the Southeast and the Mid-Atlantic, Tue, Sep 29.
- Heavy rain across portions of the Mid-Atlantic and the Northeast, Tue-Wed, Sep 29-Sep 30.
- Flooding occurring or imminent across portions of the Southeast.
- Much above normal temperatures across portions of California, the Great Basin, and the Pacific 
Northwest,  Mon-Wed, Sep 28-Sep 30.
- Much above normal temperatures across portions of the Southern Plains, Sun, Sep 27.
- Much below normal temperatures across portions of the Central Plains, the Northern Plains, the 
Upper/Middle Mississippi Valley, the Great Lakes, and the Ohio Valley, Wed-Thu, Sep 30-Oct 1.
- Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sun, Sep 27.
- Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Tue-Wed, Sep 
29-Sep 30.
- High winds across portions of the Alaska Panhandle and mainland Alaska, Sun, Sep 27.
 
Detailed Summary:

A strong upper-level high over the Pacific Northwest/Northern California Coast and associated 
upper-level ridge extending into the Southwestern corner of Texas will allow temperatures to become 
12 degrees or greater which meets the criteria for much above normal temperatures on Sunday.  The 
upper-level high and ridge will continue over the Northwest/Northern California through Friday.  
The high will allow temperatures to become much above normal over the region from Monday into 
Wednesday.  

A strong area of high pressure will develop over the the Plains and deep low pressure over the 
Great Lakes/East-Central Canada at the surface and at the upper-levels a deep upper-level trough 
roughly over the Mississippi Valley will allow temperatures over parts of the Upper Midwest to 
become much below normal on Wednesday and Thursday.  A front associated with the deep surface low 
over the Great Lakes into the Middle Mississippi Valley, on Tuesday, will move eastward to the 
Mid-Atlantic/Southeast by Wednesday will produce heavy rain over parts of the Carolinas on Tuesday. 
 The area of heavy rain will meet the criteria of one inch per 24 hours for depicting an area of 
heavy rain on the hazards map.
Likewise, the deep low and front will also produce heavy rain over parts of the Mid-Atlantic into 
the Northeast on Tuesday into Wednesday.  

Meanwhile in Alaska, deep low pressure over the Gulf of Alaska will produce strong wind over parts 
of the Gulf of Alaska Coast on Sunday.  In addition, moisture associated with the storm will 
produce an area of heavy precipitation from just northwest of Yakutat to Glacier Bay on Tuesday, 
too.  A second area of low pressure will move into the Gulf of Alaska on Tuesday remaining to 
Thursday.  This storm will have more moisture associated with it producing an area of heavy 
precipitation from Kenal Peninsula to just north of Sitka in the Alaska Panhandle on Tuesday into 
Wednesday. 

Ziegenfelder