US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
358 PM EDT Fri Oct 11 2019
 
Valid Monday October 14 2019 - Friday October 18 2019
 
Hazards:
- Heavy rain across portions of California, the Pacific Northwest, and the Northern Great Basin, 
Tue-Fri, Oct 15-Oct 18.
- Heavy rain across portions of the Lower Mississippi Valley, the Tennessee Valley, the Southern 
Mid-Atlantic, the Southern Appalachians, the Southeast, and the Southern Plains, Mon-Tue, Oct 
14-Oct 15.
- Heavy rain across portions of the Northeast, Wed-Thu, Oct 16-Oct 17.
- Flooding possible across portions of the Southeast, the Upper/Middle Mississippi Valley, the 
Great Lakes, and the Northern Plains.
- 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/Lower Mississippi Valley, and the Southern Plains.
- Much below normal temperatures across portions of the Northern/Central Plains, and the Upper 
Mississippi Valley, Mon-Wed, Oct 14-Oct 16.
- High significant wave heights for coastal portions of the Pacific Northwest, Thu-Fri, Oct 17-Oct 
18.
- 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-Thu, Oct 14-Oct 17.
- High significant wave heights for coastal portions of the Alaska Panhandle, Wed-Thu, Oct 16-Oct 
17.
- High significant wave heights for coastal portions of the Aleutians, Mon-Thu, Oct 14-Oct 17.
 
Detailed Summary:

A deep upper-level trough over Northern High Plains will bring cold air over parts of the Upper 
Midwest that will produce temperatures much below normal to the region from Monday into Wednesday.  

Meanwhile, a front and developing area of low pressure over the Middle/Lower Mississippi Valley on 
Monday will move northeastward to Southeastern Ontario, Canada and Lower 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 Southern Plains/Lower Mississippi/Tennessee Valleys roughly 
northeastward to parts of the Southeast/Southern Appalachians on Monday into Tuesday.  
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 Tuesday into Friday.  In 
addition, what was once Super Typhoon HAGIBIS will move into the Gulf of Alaska and merge with 
multiple areas of deep low pressure by Thursday.  The high winds associated with the storm 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 Pacific Northwest Coast on Thursday into Friday.

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 Wednesday.  
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 Thursday.  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 Wednesday 
into Thursday.

Ziegenfelder