US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
406 PM EDT Thu Apr 11 2019
 
Valid Sunday April 14 2019 - Thursday April 18 2019
 
Hazards:
- Heavy precipitation across portions of the Pacific Northwest and the Northern Great Basin, 
Sun-Tue, Apr 14-Apr 16.
- Heavy precipitation across portions of the Pacific Northwest, the Northern Rockies, and the 
Northern Great Basin, Sun-Mon, Apr 14-Apr 15.
- Heavy precipitation across portions of the Northeast, the Central Great Basin, the Northern 
Plains, the Northern Rockies, the Central Rockies, and the Northern Great Basin, Mon-Tue, Apr 
15-Apr 16.
- Heavy precipitation across portions of the Central Rockies and the Central Plains, Wed-Thu, Apr 
17-Apr 18.
- Heavy rain across portions of the Lower Mississippi Valley, the Central Appalachians, the 
Tennessee Valley, the Great Lakes, the Middle Mississippi Valley, the Mid-Atlantic, the Southern 
Appalachians, the Southeast, the Southern Plains, and the Ohio Valley, Tue-Thu, Apr 16-Apr 18.
- Heavy rain across portions of the Southeast, the Mid-Atlantic, the Southern Appalachians, and the 
Tennessee Valley, Sun-Mon, Apr 14-Apr 15.
- Heavy rain across portions of the Great Lakes, the Mid-Atlantic, the Northeast, the Central 
Appalachians, and the Ohio Valley, Mon-Tue, Apr 15-Apr 16.
- Severe weather across portions of the Southeast, the Mid-Atlantic, the Lower Mississippi Valley, 
the Southern Appalachians, and the Tennessee Valley, Sun, Apr 14.
- Flooding possible across portions of the Middle Mississippi Valley, the Great Lakes, the Upper 
Mississippi Valley, and the Northern Plains.
- Flooding occurring or imminent across portions of the Lower Mississippi Valley, the Northern 
Plains, the Tennessee Valley, the Northern Great Basin, the Middle Mississippi Valley, the Upper 
Mississippi Valley, the Pacific Northwest, and the Ohio Valley.
- Flooding likely across portions of the Upper Mississippi Valley and the Northern Plains.
- Much below normal temperatures across portions of the Southern Rockies, the Central Rockies, the 
Southern Plains, and the Central Plains, Sun, Apr 14.
- Heavy rain across portions of the Alaska Panhandle, Thu, Apr 18.
 
Detailed Summary:

A rather cold Canadian air mass by April standards is expected to surge southward behind the 
departing Midwest blizzard, with much below normal temperatures likely centered across the western 
High Plains for the upcoming weekend.  Temperatures are expected to be on the order of 15 to 20 
degrees below climatological averages.

A strong southern U.S. storm system will be crossing the Mid South and the Ohio Valley for Sunday 
and Monday that will be accompanied by a surge of moisture from the Gulf of Mexico.  Heavy rain is 
likely for the southern Appalachians and extending into northern Georgia on Sunday, and then the 
threat of heavy rain becomes likely across the northeast U.S. on Monday, with rainfall totals on 
the order of 1 to 3 inches anticipated.  Some severe weather is expected across parts of the Deep 
South on Sunday in the warm sector of this storm system.

By the middle of next week, a second storm with a similar track across the south-central U.S. will 
likely bring another round of heavy rainfall from the central Gulf Coast to the middle Mississippi 
River Valley for Tuesday and Wednesday, with the potential for 1 to 2 inches of rainfall with 
locally higher amounts.  Severe weather is also possible with this event, but the magnitude and 
timing of any severe weather remains uncertain.

Across the western U.S., a series of systems will move across the Pacific Northwest and 
northern/central Intermountain region during this forecast period.  The model consensus here 
generally supports a marginal threat for heavy precipitation (mostly snow) across parts of the 
northern Rockies and across parts of Idaho as an upper trough amplifies after crossing the West 
Coast.  Elevation dependent snow is also likely for the Washington and Oregon Cascades.

Over Alaska, there is the possibility for heavy precipitation across the southeast Panhandle region 
towards the end of the forecast period on April 18th as a plume of enhanced Pacific moisture is 
advected inland and is orographically enhanced by the terrain, with QPF generally on the order of 
an inch expected.

Hamrick