US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
406 PM EDT Wed May 19 2021
 
Valid Saturday May 22 2021 - Wednesday May 26 2021
 
Hazards:
- Heavy rain across portions of the Southern Plains, Sun, May 23.
- Flooding possible across portions of the Middle Mississippi Valley, the Lower Mississippi Valley, 
and the Southern Plains.
- Flooding occurring or imminent across portions of the Central Plains, the Middle Mississippi 
Valley, the Lower Mississippi Valley, and the Southern Plains.
- Flooding likely across portions of the Central Plains, the Middle Mississippi Valley, the Lower 
Mississippi Valley, and the Southern Plains.
- Much above normal temperatures across portions of the Great Lakes and the Upper Mississippi 
Valley, Sat-Sun, May 22-May 23.
- Much above normal temperatures across portions of the Southeast and the Mid-Atlantic, Mon-Tue, 
May 24-May 25.
 
Detailed Summary:

The main weather hazard during the medium-range forecast period (Saturday, May 22 - Wednesday, May 
26) will be anomalous warmth in the Midwest and East Coast. A troughing pattern in the west will 
lead to an active period of rain and thunderstorms for parts of the Northern/Southern Plains. 
There's a chance for heavy rainfall along the Texas coast on Friday and Saturday as the dipole of 
upper-level troughing in the west and ridging in the east pulls Gulf moisture into eastern Texas 
and the Plains/Mississippi Valley. This rain threat may be of particular concern given the already 
high soil moisture and ongoing flooding across the region. Meanwhile, rain and thunderstorms will 
be the mode across much of the Northern/Southern Plains this weekend. Rainfall, particularly over 
parts of the border between Canada and the Northern Plains will be much needed due to an ongoing 
severe drought. The eastern migration of the upper-level dipole will lead to warm air advection 
into the Midwest and Great Lakes this weekend. This warmth will be anomalous as some places across 
Michigan and Wisconsin may see their temperatures reach up into the mid to upper 80s, which would 
be between 15-20 degrees above average. This anomalous warmth will spread into the Mid-Atlantic and 
Southeast by the beginning of next week, when a prolonged period of above average high temperatures 
and increased humidity may lead to the threat for excessive daytime heat. Temperatures are likely 
to be well above normal for much of the Virginia Piedmont down into Southern Georgia between Monday 
and Tuesday. A boundary extending from the Central/Southern Plains through the Ohio Valley will be 
the focus for potentially heavy rain and thunderstorms by the middle of next week. Model data seems 
to have good agreement on the spatial extent of the heavy rain threat, particularly over eastern 
Kansas into western Missouri, but not with regards to amounts.

A quiet period is expected for Alaska during the medium range period as a sequence of waves are 
expected to produce light precipitation along the Gulf coast this weekend.

Kebede