NOUS41 KWBC 231755



Service Change Notice 18-21

National Weather Service Headquarters Washington DC

255 PM EST Fri Feb 23 2018


To:       Subscribers:

          -NOAA Weather Wire Service

          -Emergency Managers Weather Information Network


          Other NWS partners and NWS employees


From:     David Novak

          Director, Weather Prediction Center (WPC)


Subject:  Transition of Experimental WPC Day 4-7 Web-based

          Winter Weather Outlook to operational status on or

          about March 27, 2018.


Effective on or about March 27, 2018, the Weather Prediction

Center (WPC) will transition the web-based Day 4-7 Winter

Weather Outlook from experimental to operational.


The WPC Day 4-7 Web-based Winter Weather Outlook is a graphical

forecast depicting the probability of winter precipitation

(snow/sleet) exceeding 0.25 inches (~6 mm) water equivalent over

a 24-hour period (12Z to 12Z). The product is comprised of four

separate graphics showing the forecast for Day 4, Day 5, Day 6

and Day 7. The product is prepared twice daily by 0900

Coordinated Universal Time (UTC) and 1930 UTC.


Graphical representations of the products are online at:


More information about this product is in the Product

Description Document at the following link:


For questions regarding this notice, please contact:



James Nelson (W/NP32)

College Park, MD 20740



WS Service Change Notices are online at: