US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
438 PM EDT Thu Oct 10 2019
 
Valid Sunday October 13 2019 - Thursday October 17 2019
 
Hazards:
- Heavy rain across portions of the Northeast, the Pacific Northwest, the Northern Mid-Atlantic, 
California, and the Lower Great Lakes, Wed-Thu, Oct 16-Oct 17.
- Heavy rain across portions of the Southeast, the Southern Mid-Atlantic, the Lower Mississippi 
Valley, the Southern Appalachians, and the Tennessee Valley, Mon-Wed, Oct 14-Oct 16.
- Flooding possible across portions of the Plains, the Upper/Middle Mississippi Valley, and the 
Great Lakes.
- Flooding occurring or imminent across portions of the Northern/Central Plains, the Upper/Middle 
Mississippi Valley, and the Great Lakes.
- Flooding likely across portions of the Middle Mississippi Valley and the Northern Plains.
- Much below normal temperatures across portions of the Northern/Central Plains, the Upper/Middle 
Mississippi Valley, and the Great Lakes, Sun-Wed, Oct 13-Oct 16.
- Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Tue-Wed, Oct 
15-Oct 16.
- High winds across portions of the Aleutians, Mon-Wed, Oct 14-Oct 16.
- High significant wave heights for coastal portions of the Alaska Panhandle, Thu, Oct 17.
- High significant wave heights for coastal portions of the Aleutians, Mon-Wed, Oct 14-Oct 16.
 
Detailed Summary:

A deep storm and upper-level trough over Western Ontario, Canada will bring cold air over parts of 
the Upper Midwest that will produce temperatures much below normal to the region from Sunday into 
Wednesday.  Meanwhile, a front and developing area of low pressure over the Middle/Lower 
Mississippi Valley on Sunday will move northeastward to the Great Lakes by Wednesday.  Moisture 
from the Gulf of Mexico will stream northward intersecting the boundary that will produce an area 
of heavy rain from parts of the Lower Mississippi/Tennessee Valleys roughly northeastward to parts 
of the Southeast/Southern Appalachians on Monday into Wednesday.  Additionally, the area of low 
pressure over Southeastern Ontario, Canada and Lower Great Lakes will move eastward to the 
Northeast by Thursday.  The system and moisture pooling a long the associated front will produce 
rain over parts of the Northeast resulting in an area of heavy precipitation over parts of the area 
on Wednesday into Thursday.  

Elsewhere, an approaching front over the Eastern Pacific and week moisture supply along with 
onshore flow off the Pacific will aid in producing an area of heavy rain over parts of the Pacific 
Northwest Coast into a small part of the Northern California Coast on Wednesday into Thursday.  

Over Alaska on Monday into Wednesday, what was once Super Typhoon HAGIBIS will become extra 
tropical and become a deep area of low pressure moving across parts of the Aleutian Islands then 
move eastward into the Gulf of Alaska merging with another area of deep low pressure by Tuesday. 
The storm will bring high winds of 50 knots or greater and significant waves of 20 feet or greater 
to the Aleutians on Monday into Wednesday.  Moisture associated with the deep storm over the Gulf 
of Alaska will aid in producing an area of heavy precipitation over the Alaska Panhandle on Tuesday 
into Wednesday.  On Wednesday into Thursday a third area of low pressure over the Bering Sea will, 
likewise, merge with what was once Super Typhoon HAGIBIS over the Gulf of Alaska.  The area of very 
deep low pressure and the long path the wind travels over the ocean will aid in producing an area 
significant waves of 20 feet or greater to parts of the Southern Panhandle of Alaska on Thursday.  

Ziegenfelder