US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
250 PM EDT Mon Oct 14 2019
 
Valid Thursday October 17 2019 - Monday October 21 2019
 
Hazards:
- Heavy precipitation across portions of the Pacific Northwest and the Northern Great Basin, 
Thu-Sat, Oct 17-Oct 19 and Mon, Oct 21.
- Heavy rain across portions of the Central Plains, the Lower Mississippi Valley, the Tennessee 
Valley, the Great Lakes, the Middle Mississippi Valley, the Mid-Atlantic, the Southern 
Appalachians, the Upper Mississippi Valley, the Southeast, the Southern Plains, and the Ohio 
Valley, Sun-Mon, Oct 20-Oct 21.
- Heavy rain across portions of the Northeast and the Great Lakes, Thu, Oct 17.
- Heavy snow across portions of the Northern Plains, the Northern Rockies, and the Northern Great 
Basin, Sat-Sun, Oct 19-Oct 20.
- Flooding possible across portions of the Northern Plains.
- Flooding occurring or imminent across portions of the Central Plains, the Middle Mississippi 
Valley, the Great Lakes, the Upper Mississippi Valley, and the Northern Plains.
- Flooding likely across portions of the Northern Plains.
- High winds across portions of the Great Lakes, the Mid-Atlantic, the Northeast, the Central 
Appalachians, and the Ohio Valley, Thu-Fri, Oct 17-Oct 18.
- High significant wave heights for coastal portions of the Pacific Northwest, Thu, Oct 17.
- Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sun-Mon, Oct 
20-Oct 21.
 
Detailed Summary:

The medium range period will begin on Thursday, October 17th with a powerful low pressure system 
located over or just off the New England coast. Heavy rain is forecast from Upstate New York to 
Maine between Thursday and Friday, with total rainfall amounts around 1 to 3 inches. High winds of 
at least 34 mph sustained will also accompany the system from the northern Mid-Atlantic to New 
England. Higher wind gusts upwards of 50 mph will be possible along the New England coastline as 
well. Cool air will rush into the region Thursday and Friday, but temperatures don't appear cold 
enough to add a highlighted area on the hazards graphic today.

Across the Northwest an active storm pattern will set up with several round of heavy rain and 
mountain snow. Significant waves will be possible on Thursday along the Washington and northern 
Oregon coasts as a potent system moves onshore. As this system continues inland it is forecast to 
bring heavy snow to portions of the Northern Rockies, particularly across the higher elevations of 
Idaho, Montana, and northwest Wyoming. 

The medium range period is forecast to end with a deepening low pressure system over the 
north-central United States. Current guidance shows high confidence in a widespread area of heavy 
rain (greater than 1 inch in 24 hours) ahead of an associated cold front from the Gulf Coast to the 
Great Lakes on Sunday (October 20) and Monday (October 21). Tropical moisture from a weak low 
pressure system in the Gulf of Mexico could also add to the heavy rain threat across the Gulf Coast 
states. Heavy rain will also be possible to the north and west of the low pressure across the Upper 
Midwest, but confidence was not high enough here to add a highlighted area at the moment. During 
this time period temperatures are forecast to be around 5 to 10 degrees above average east of the 
Mississippi River and around 5 to 10 degrees below average to west.

For Alaska, the medium range period will start with remnants of former Typhoon Hagibis weakening 
and being absorbed with a new low pressure forming just south of Alaska. This will lead to gusty 
winds and scattered showers across the area. By Sunday and Monday a separate low pressure system is 
forecast to swing into the Alaskan Panhandle and bring heavy rain/mountain snow.  

Snell