US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
414 PM EDT Fri Apr 10 2020
 
Valid Monday April 13 2020 - Friday April 17 2020
 
Hazards:
- Heavy rain across portions of the Southeast, Tue-Wed, Apr 14-Apr 15.
- Heavy rain across portions of the Mid-Atlantic and the Northeast, Mon, Apr 13.
- Heavy snow across portions of the Central/Southern Plains, the Central/Southern Rockies, the 
Upper Mississippi Valley, and the Great Lakes, Mon, Apr 13.
- Severe weather across portions of the Southeast and the Mid-Atlantic, Mon, Apr 13.
- Flooding possible across portions of the Northern Plains, the Tennessee Valley, the Mid-Atlantic, 
the Southern Appalachians, the Southeast, and the Ohio Valley.
- Flooding occurring or imminent across portions of the Mississippi Valley, the Southern Plains, 
and the Northern Plains.
- High winds across portions of the Northeast, the Central/Southern Appalachians, the Tennessee 
Valley, the Mid-Atlantic, the Southeast, the Great Lakes, and the Ohio Valley, Mon, Apr 13.
- Much below normal temperatures across portions of the Plains, the Mississippi Valley, the Central 
Great Basin, the Tennessee Valley, the Great Lakes, and the Ohio Valley, Mon-Fri, Apr 13-Apr 17.
- Heavy precipitation across portions of mainland Alaska, Mon-Thu, Apr 13-Apr 16.
- High winds across portions of mainland Alaska and the Aleutians, Wed-Fri, Apr 15-Apr 17.
- High winds across portions of mainland Alaska, Mon, Apr 13.
- Much above normal temperatures across portions of mainland Alaska, Mon-Wed, Apr 13-Apr 15.
 
Detailed Summary:

The medium-range period will begin on Monday 4/13 with a deep surface low pressure system over the 
Great Lakes region. On the backside of this low, heavy snow is expected for portions of the Upper 
Midwest and Upper Great Lakes region. To the east, warm temperatures should keep precipitation as 
rain in the Northeast, and the potential exists for heavy rain over an inch. Rain falling on 
snowpack over Maine and New Hampshire could cause flooding concerns there. Meanwhile, severe 
weather is possible ahead of the cold front along portions of the Eastern Seaboard on Monday as 
well. Additionally, high winds are a threat due to the tight pressure gradient from the strong 
low--from the low's vicinity over the Great Lakes to the Eastern Seaboard.

A large-scale upper-level trough is expected to be persistently centered over the central U.S. 
through much of next week. At the surface, a potent cold front associated with the low should pass 
through the East early in the week and high pressure should build in behind. Thus, cold 
temperatures are forecast from the Rockies eastward through the central U.S. and approaching the 
East. The core of the much below average temperatures will migrate from the Rockies and High Plains 
early in the week toward the north-central U.S. by Wednesday into Thursday. Cool temperatures 
should moderate a bit by Friday and press eastward toward the Mid-Atlantic and Northeast, but low 
temperatures are not currently expected to be too far below average.

Upper-level impulses dropping southward through the western part of the trough could lead to heavy 
snow over portions of the Rockies through next week. The highest likelihood right now appears to be 
over portions of the Central/Southern Rockies Monday into Tuesday, which could even spread some 
lighter snow into the Central/Southern High Plains--this will continue to be monitored into the 
short range period. The Northern/Central Rockies and Wind River Mountains/Tetons could see more 
snow around midweek, but higher amounts seem mainly confined to high elevations at this point.

Over Alaska, upper-level ridging is forecast to persist over the state through much of the week, 
relaxing by Friday. This will cause above average temperatures to persist over the state, 
especially for minimum temperatures, with the highest anomalies forecast for the North Slope. 
Anomalously moist air flowing northward across a good portion of the Pacific Ocean is expected to 
make its way into the Gulf of Alaska coastal region and persist for much of the week, which should 
cause heavy precipitation centered over the Kenai Peninsula and nearby. Localized high winds in 
favored gap wind areas are possible near there on Monday. Then, as a low pressure system makes its 
way toward the Aleutians, some marginally high winds could occur there later in the week.

Tate