US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
445 PM EDT Fri Mar 20 2020
 
Valid Monday March 23 2020 - Friday March 27 2020
 
Hazards:
- Heavy precipitation across portions of the Olympic Peninsula, Fri, Mar 27.
- Heavy rain across portions of the coastal section of New Jersey, Long Island and southeastern New 
England, as well as across the Mid-Mississippi Valley through the southern Appalachians, Mon-Tue, 
Mar 23-Mar 24.
- Heavy rain from the Mid-Mississippi Valley through much of the Ohio Valley into the southern 
Appalachians, Fri, Mar 27.
- Heavy snow along the southern Cascades, Mon-Tue, Mar 23-Mar 24 and Fri, Mar 27.
- Heavy snow along the northern Cascades, Thu-Fri, Mar 26-Mar 27.
- Heavy snow along much of the Sierra Nevada, Mon-Tue, Mar 23-Mar 24.
- Heavy snow from across the higher elevations of western Wyoming down into northern Utah, Tue, Mar 
24.
- Heavy snow across portions of central Idaho, Mon, Mar 23.
- Severe weather across portions of the southern Plains, Mon, Mar 23.
- Flooding possible across portions of the Mid-Mississippi Valley, the southern Plains, and the 
Upper Midwest.
- Flooding occurring or imminent across portions of the lower and middle Mississippi Valley, 
scattered locations in the northern and southern Plains, and a couple of areas in the Southeast.
- Flooding likely across portions of the central and southern Plains, as well as the middle 
Mississippi Valley.
- Heavy snow across portions of the Alaska Range, Mon-Tue, Mar 23-Mar 24.
- Much above normal temperatures for much of northwestern and northern Alaska, Mon-Wed, Mar 23-Mar 
25.
 
Detailed Summary:

The medium-range period (Monday 3/23 to Friday 3/25) will feature another significant upper-level 
trough moving into the western U.S. as a couple of low pressure system tracks across the eastern 
two-thirds of the country.  The period will begin will a low pressure system getting ready to move 
off the Mid-Atlantic coast.  Models generally agree that the low will deepen quickly as it tracks 
to the southeast of New England.  The main question continues to be the amount of wintry 
precipitation that may fall across parts of the Northeast.  Models have shown a general uptick in 
the snowfall amounts for this area, with the ECMWF continues to be the most aggressive model in 
this regard.  Therefore, a heavy snow area is indicated for parts of the interior Northeast from 
Monday into early Tuesday where heavy wet snow is possible. In addition to the snow, rain could be 
heavy across portions of the coastal section of New Jersey, Long Island and southeastern New 
England before the coastal storm moves farther out to sea later on Tuesday.

Across the western U.S., a persistent upper-level trough and multiple impulses of upper-level 
energy will lead to cooler than average temperatures together with a good chance of precipitation. 
The most impactful weather will be found across the Sierra Nevada, where another round of heavy 
snow will likely to continue through next Tuesday. Elsewhere in the West, the broad coverage of the 
upper trough will extend the potential for heavy snow farther inland into the higher elevations of 
western Wyoming, northern Utah, and central Idaho on Monday and/or Tuesday. The central and 
southern Cascades will also be susceptible to heavy snow. By the end of next week, a weakening 
occluded cyclone is forecast to bring the next threat of heavy snow into the northern Cascades and 
the higher terrains of the Olympic Peninsula most likely on Friday.

In Alaska, the recent anomalously mild and snowy weather is expected to extend into the 
medium-range period as the next chance of heavy snow spreads across portions of the Alaska Range 
Monday into Tuesday. Temperatures are forecast to run 20 to 40 degrees above average across 
northern Alaska through Wednesday, which could mean the first time at or above freezing since 
autumn for this portion of the state.  By the latter part of next week, models indicate that an 
upper-level trough from the Arctic Ocean will drop south toward Alaska, especially the ECMWF/EC 
ensemble mean.  This will signal a return to much colder and drier conditions from north to south 
across Alaska toward the end of next week.

Kong