US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
352 PM EDT Wed Apr 29 2020
 
Valid Saturday May 02 2020 - Wednesday May 06 2020
 
Hazards:
- Heavy rain across portions of the Central/Southern Plains, the Middle/Lower Mississippi Valley, 
the Tennessee Valley, the Southern Appalachians, and the Ohio Valley, Mon-Tue, May 4-May 5.
- Heavy rain across portions of the Upper Mississippi Valley and the Northern Plains, Sun-Mon, May 
3-May 4.
- Heavy rain across portions of the Southern/Central Appalachians, the Middle Mississippi Valley, 
the Ohio Valley, and the Tennessee Valley, Sat-Sun, May 2-May 3.
- Flooding possible across portions of the Northeast, the Central Appalachians, the Middle/Upper 
Mississippi Valley, the Mid-Atlantic, the Great Lakes, and the Ohio Valley.
- Flooding occurring or imminent across portions of the Southeast, the Mississippi Valley, and the 
Northern Plains.
- Flooding likely across portions of the Southeast, the Middle Mississippi Valley, and the Northern 
Rockies.
- Much above normal temperatures across portions of California and the Southwest, Tue-Wed, May 
5-May 6.
- Much above normal temperatures across portions of the Central/Southern Plains, the 
Central/Southern Rockies, the Central Great Basin, and the Southwest, Sat-Wed, May 2-May 6.
- Much above normal temperatures across portions of the Central Rockies, the Central Great Basin, 
and the Southern/Central Plains, Sat-Mon, May 2-May 4.
- Much above normal temperatures across portions of the Southern Plains, Sat-Tue, May 2-May 5.
 
Detailed Summary:

The medium range period will begin on Saturday 5/2 with an upper-level low over the Northeast and 
upper-level ridging over the central U.S. An upper high slowly making its way northward from 
central Mexico should help keep heights above normal through the period over the southwestern 
quadrant of the nation. This will lead to much above normal temperatures over the Four Corners 
states and into the Central/Southern Plains through Monday, with much of Texas experiencing the 
heat through Tuesday. Record highs are possible for the Southern Plains over the weekend, with 
temperatures nearing 100 degrees or even exceeding it in parts of Texas. The Southwest is forecast 
to remain hot as well, with temperatures increasing a few degrees on Tuesday and Wednesday of next 
week.

Potential for heavy rainfall exists over the weekend as moisture increases along a frontal system 
moving through the Ohio Valley. The best chance for heavy rain is currently outlined over the Ohio 
Valley and Central Appalachians, though differences in the latitude of the axis of heaviest rain 
remain. Additionally, rain which could be heavy may occur to the east somewhere over the 
Mid-Atlantic, but the area of heaviest rain is even more uncertain there.

Early next week, an upper-level trough/low is forecast to move into the Northwest and eastward into 
the Northern Plains by Tuesday, bringing chances for precipitation over those areas. Over the 
Pacific Northwest, precipitation does not seem to be anomalously high, but once precipitation 
spreads into the Northern High Plains, even rain amounts around an inch would be unusually high, so 
a heavy rain hazard area was placed there. Recent model guidance has trended lower with rain 
amounts compared to the past couple of days, and focused a little farther east, so will continue to 
monitor if these trends continue. Most precipitation should fall as rain, but higher elevation 
light snows in the Cascades and Northern Rockies are expected as temperatures cool down with the 
trough. Windy conditions are also possible over the Great Basin Sunday and over the Rockies and 
Plains Monday, but winds should remain below hazards criteria. Downstream of the trough, another 
round of heavy rainfall is possible over portions of the Mississippi, Tennessee, and Ohio Valleys. 
Once again, confidence in the placement of the heavy rain is not too high, but moisture flowing 
into the vicinity of and overrunning a front is expected and could create a threat.

Over Alaska, no hazards are posted. However, ice jam and snowmelt flooding are possible over 
portions of the mainland, though specific locations where these issues could occur are hard to pin 
down in advance. Precipitation is forecast for the Panhandle and then for the Gulf of Alaska coast 
as a low pressure system sits over the Northeast Pacific, but widespread heavy amounts are not 
currently expected, and temperature anomalies are not expected to be significant.

Tate