US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
322 PM EST Fri Mar 01 2019
 
Valid Monday March 04 2019 - Friday March 08 2019
 
Hazards:
- Heavy rain across portions of California, Tue-Wed, Mar 5-Mar 6.
- Heavy snow for the Sierra Nevada, Tue-Thu, Mar 5-Mar 7.
- Heavy snow across portions of the Northern and Central Rockies, Wed-Thu, Mar 6-Mar 7.
- Heavy snow across portions of the Central and Southern Rockies, Wed-Fri, Mar 6-Mar 8.
- Heavy snow across portions of Northern New England, Mon, Mar 4.
- Flooding possible across portions of the Mid-Atlantic.
- Flooding occurring or imminent across portions of the Lower Mississippi Valley, the Tennessee 
Valley, the Middle Mississippi Valley, the Mid-Atlantic, the Southeast, and the Ohio Valley.
- Much below normal temperatures from portions of the Northwest to the Great Lakes and the 
Northeast, Mon-Fri, Mar 4-Mar 8.
- Much below normal temperatures from the Central and Southern Plains to the Ohio Valley and the 
Southeast, Mon-Wed, Mar 4-Mar 6.
- High winds across portions of western Alaska and the Alaskan Peninsula, Mon-Wed, Mar 4-Mar 6.
- High winds across portions of the Aleutians, Wed-Fri, Mar 6-Mar 8.
- High significant wave heights for coastal portions of mainland Alaska, Mon-Tue, Mar 4-Mar 5.
- High significant wave heights for coastal portions of the Aleutians, Wed-Fri, Mar 6-Mar 8.
 
Detailed Summary:

A storm system expected to bring heavy rain and snow this weekend to the Eastern U.S. will exit the 
Mid-Atlantic coast by early Monday. Heavy snowfall across portions of New England will likely be 
ongoing on Monday, ending by early Tuesday as the low moves farther offshore. Behind this system, a 
cold arctic airmass will filter into the Central U.S., spreading eastward into much of the East by 
early to middle of next week. Temperatures across most of the central and eastern states could be 
as much as 20 to 40 degrees below normal for this time of the year, with below normal temps also 
extending into parts of the Northwest. Temperatures across the southern half of this area (from the 
central/southern Plains to the Ohio Valley/Southeast) should moderate to near or slightly above 
normal by Thursday and Friday of next week, but much of the northern tier (from the Northwest to 
the Great Lakes and the Northeast) should remain below normal through most of the week.

Besides the anomalous cold, the biggest weather system in the medium range period will be out West 
as an upper level system moves through California and into the intermountain West. In California, 
another round of heavy snow can be expected for the Sierra Nevada with heavy rainfall likely along 
the coast and in the lower elevations Tuesday and into Wednesday, March 5th and 6th. Given heavy 
rainfall in the short range period, and increased sensitivity in this region (especially over burn 
scars in southern California), flooding and flash flooding may be a threat. This same system is 
also expected to produce heavy snowfall for the higher elevations of the northern and central 
Rockies as well Tuesday, Wednesday, and lingering into Thursday. The leftover energy from this 
system may eject into the Plains by the end of next week, but there continues to be significant 
uncertainty as to what, if any, impact this may have on sensible weather with some models hinting 
at the potential for a swath of snowfall across the middle Mississippi Valley into parts of the 
Ohio Valley next Thursday into Friday. Given the uncertainty associated with this, opted to not 
include a heavy snowfall area on the hazards chart today, but this system will certainly need to be 
monitored in the coming days. 

In Alaska, a lead system moving northward through the eastern Bering sea is likely to bring high 
winds to parts of the Panhandle and western Alaska the first half of next week. Significant waves 
are also possible, particularly for the Bering straight region (from Saint Lawrence Island to Point 
Hope), which may result in the potential for coastal flooding. Behind this by mid-week, a series of 
deep surface lows are forecast to impact the Aleutians and likely to result in high winds and waves 
for much of the Aleutian island chain next Wednesday through Friday.

Santorelli