US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
343 PM EDT Fri Sep 27 2019
 
Valid Monday September 30 2019 - Friday October 04 2019
 
Hazards:
- Heavy rain across portions of the Plains, the Upper/Middle Mississippi Valley, the Great Lakes, 
the Southern Rockies, and the Southwest, Mon-Thu, Sep 30-Oct 3.
- Flooding possible across portions of the Central Plains, the Upper/Middle Mississippi Valley, and 
the Great Lakes.
- Flooding occurring or imminent across portions of the Northern/Central Plains and the 
Upper/Middle Mississippi Valley.
- Much above normal temperatures across portions of the Northern/Central Plains, the Upper/Middle 
Mississippi Valley, and the Great Lakes, Mon, Sep 30.
- Much above normal temperatures across portions of the Middle/Lower Mississippi Valley, the Great 
Lakes, the Ohio Valley, the Tennessee Valley, the Central/Southern Appalachians, the Mid-Atlantic, 
and the Southeast, Mon-Fri, Sep 30-Oct 4.
- Much below normal temperatures across portions of the Northern/Central Plains, the Central Great 
Basin, the Northern/Central Rockies, California, the Northern Great Basin, and the Pacific 
Northwest, Mon-Thu, Sep 30-Oct 3.
- Heavy rain across portions of the Alaska Panhandle and mainland Alaska, Mon-Tue, Sep 30-Oct 1.
 
Detailed Summary:

The upper-level pattern of troughing in the western U.S. and ridging in the eastern U.S. is 
expected to remain persistent through about next Wednesday. With this amplified pattern, 
temperatures are forecast to be quite anomalous, with colder than average temperatures in the West 
and warmer than average temperatures in the central to eastern U.S. Cold temperatures in the West 
will be around 10-15 degrees below average for lows while highs will be 15-30 degrees below 
average, with widespread records forecast, especially record low maximum temperatures. The warm 
temperatures farther east will occur ahead of a cold front that is expected to track southeastward 
through the period, so the region from the Central Plains to the Middle and Upper Mississippi 
Valley delineated for Much Above Normal Temperatures will cool down behind the front after Tue. The 
Ohio Valley and southward will remain warm through Wed, and much warmer than average temperatures 
could spread into the Great Lakes region and Northeast too, but only for about a day at a time. All 
these areas could experience record high temperatures--likely dozens of temperature records will be 
broken by late next week. By Thu/Fri, upper troughing is forecast to press southward into the 
northeastern quadrant of the U.S., and a cooler surface high will come in behind the aforementioned 
front. Thus by Friday, above normal temperatures should be confined to the Southeast, while the 
Northeast to Mid-Atlantic regions finally get a taste of fall. 

In between the trough and ridge, moisture streaming into the center of the country will lead to 
heavy rainfall. Portions of the Southern Rockies to the Plains, Mississippi Valley, and Great Lakes 
region have the potential for several inches of rain. The cold front will provide a focus for 
rainfall, so the locations expected to receive heavy rainfall should shift slowly southeastward 
from Mon to Thu.

In Alaska, model guidance signal remains in good agreement that heavy rainfall should occur on 
Mon/Tue as a surface low pressure system moves toward the southern coast. Some snow is possible in 
higher elevations, and some gusty winds could occur as well. Later in the week, another low is 
currently forecast to approach the western Alaska coast, but model uncertainty becomes greater. A 
high wind hazard area may be needed along the western coast and/or for the Aleutians if confidence 
increases in the next few days with this low. 


Tate