US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
247 PM EDT Wed Apr 10 2019
 
Valid Saturday April 13 2019 - Wednesday April 17 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 Central Rockies, the Central Great Basin, the Northern 
Rockies, the Northern Great Basin, and the Northern Plains, Mon-Tue, Apr 15-Apr 16.
- Heavy precipitation across portions of the Northern Rockies and the Northern Great Basin, 
Sun-Mon, Apr 14-Apr 15.
- Heavy rain across portions of the Mid-Atlantic, the Lower Mississippi Valley, the Central 
Appalachians, the Tennessee Valley, the Great Lakes, the Middle Mississippi Valley, the Northeast, 
the Southern Appalachians, the Southeast, the Southern Plains, and the Ohio Valley, Sat-Sun, Apr 
13-Apr 14.
- Heavy rain across portions of the Lower Mississippi Valley, the Tennessee Valley, the Middle 
Mississippi Valley, the Southern Appalachians, the Southeast, the Southern Plains, and the Ohio 
Valley, Wed, Apr 17.
- Heavy rain across portions of the Northeast, Mon-Tue, Apr 15-Apr 16.
- Heavy snow across portions of the Northeast, Mon-Tue, Apr 15-Apr 16.
- Severe weather across portions of the Southeast, the Lower Mississippi Valley, the Southern 
Plains, and the Tennessee Valley, Sat, Apr 13.
- Severe weather across portions of the Southeast, the Mid-Atlantic, 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 Rockies, the Middle Mississippi Valley, the Northern 
Great Basin, the Upper Mississippi Valley, the Pacific Northwest, and the Ohio Valley.
- Flooding likely across portions of the Central Plains, the Northern Plains, the Northern Great 
Basin, the Middle Mississippi Valley, the Upper Mississippi Valley, and the Southern Plains.
- Much below normal temperatures across portions of the Central Plains, the Central Rockies, the 
Northern Plains, the Southern Rockies, the Upper Mississippi Valley, and the Southern Plains, 
Sat-Sun, Apr 13-Apr 14.
 
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 across the central and 
southern High Plains for the upcoming weekend.  The core of the coldest air will be across the 
western High Plains on Saturday and temperatures should begin to moderate somewhat by Sunday.

The next upper level trough from the Pacific will reach the Plains on Saturday.  A surface frontal 
boundary associated with this shortwave trough will serve as a focusing mechanism for deep Gulf of 
Mexico moisture and support heavy rainfall developing over the southern Plains and lower-mid 
Mississippi Valley on Saturday.  There is decent model agreement for areal average rainfall totals 
in the 1 to 4 inch range across this region by Sunday morning.  This system is expected to quickly 
lift northeastward across the Tennessee and Ohio Valleys on Sunday, with Gulf moisture and a 
pre-frontal unstable air mass resulting in organized convection across the mid-Atlantic and 
southeastern states.  Rainfall amounts should generally be less than what is expected on Saturday 
as the system is progressive and the moisture flux is not as great.  Rainfall totals of 1-2 inches 
are likely along the front, with higher amounts possible across the Southeast where a surface wave 
along the front may develop.  The Storm Prediction Center is also depicting the potential for 
severe weather from eastern Texas to Georgia this weekend in the warm sector of this storm system.

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, the pattern looks rather quiet as the main polar jet steers storms south of the state. 
 There is the possibility for heavy precipitation across the southeast Panhandle region towards the 
end of the forecast period, but confidence is too limited at this time to include a separate hazard 
on the map.

Hamrick