US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
339 PM EDT Fri Mar 19 2021
 
Valid Monday March 22 2021 - Friday March 26 2021
 
Hazards:
- Heavy rain across portions of the Lower Mississippi Valley, the Tennessee Valley, the 
Mid-Atlantic, the Southern Appalachians, the Southeast, the Southern Plains, and the Ohio Valley, 
Tue-Thu, Mar 23-Mar 25.
- Heavy rain across portions of the Central/Southern Plains, and the Upper/Middle Mississippi 
Valley, Mon, Mar 22.
- Heavy snow across portions of the Central Great Basin, the Pacific Northwest, the Northern 
Rockies, and the Northern Great Basin, Mon, Mar 22.
- Heavy snow across portions of the Central/Southern Rockies, the Central Great Basin, and the 
Central/Southern Plains, Tue, Mar 23.
- Flooding possible across portions of the Central Plains, the Middle Mississippi Valley, the 
Southern Appalachians, the Ohio Valley, and the Tennessee Valley.
- Flooding occurring or imminent across portions of the Central/Southern Plains, the Middle 
Mississippi Valley, the Ohio Valley, and the Tennessee Valley.
- Flooding likely across portions of the Central Plains, the Middle/Lower Mississippi Valley, and 
the Ohio Valley.
 
Detailed Summary:

The medium-range forecast period (Monday, March 22nd to Friday, March 26th) features an area of 
high pressure just off the coast of Maine and low pressure off the Carolina Coast on Monday.  There 
will be a tight pressure gradient along the Mid-Atlantic and the Southeast Coast on Monday.  The 
wind will be below the criteria for high wind yet still be quite breezy with no area depicted on 
the Hazards Chart.  The breezy wind will move northward along the coast to northern Mid-Atlantic 
and Southern New England on Tuesday.  The low will move farther offshore on Wednesday, with the 
wind becoming weaker. 

Meanwhile, a front extending from the Upper Midwest to the Central/Southern High Plains, with a 
low-pressure wave over the Southern High Plains, will intersect moisture flowing northward over the 
Plains, producing an area of heavy rain over parts of the Middle Mississippi Valley and Central 
Plains on Monday.  Ahead of the front, temperatures will be about 12 degrees above average over the 
Upper Midwest on Monday into Tuesday and expand into parts of the Northeast/Ohio Valley on 
Wednesday and Thursday.  These temperatures will not be a hazard as the high will be in the 60s.

In the meantime, northeasterly flow and upper-level energy will help produce heavy snow over parts 
of the Cascades and parts of the Bitterroot Range/Salmon Range and the Caribou Range/Portneuf 
Range/Bannock Range on Monday. 

A deepening low-pressure wave over the Central High Plains will move into Ontario, Canada, by 
Thursday.  The associated front will become quasi-stationary over the Lower Mississippi/Tennessee 
Valleys on Tuesday into Thursday.  The boundary will help develop rain over parts of the Lower 
Mississippi Valley and Southern Plains on Tuesday. The rain will expand into parts of the Ohio 
Valley, Southern Appalachians, and Southeast on Wednesday and Thursday, later developing into 
hazardous heavy rain in the same area.

For Alaska, an area of low pressure over the North Pacific on Monday will move into the Gulf of 
Alaska on Tuesday.  The associated plume of moisture will be weaker and steer more into British 
Columbia.  However, an area of precipitation will develop over parts of the panhandle on Tuesday 
into early Wednesday.  Another area of low pressure will be over the Bering Sea on Wednesday, and 
later move inland over the mainland on Thursday.  There will be an area of strong wind associated 
with the low over parts of the Western Mainland on Wednesday.  The system will produce snow over 
the Western Mainland on Wednesday and extend into parts of the Alaska Range's western end.

Ziegenfelder