NOUS41 KWBC 221820 AAA



Public Information Statement 17-30 Updated

National Weather Service Headquarters Washington DC

220 PM EDT Tue Aug 22 2017


To:      Subscribers:

         -NOAA Weather Wire Service

         -Emergency Managers Weather Information Network


         Other NWS Partners and NWS Employees


From:    Michelle Hawkins, Chief

         Severe, Fire, Public, and Winter Weather

          Services Branch


Subject: Updated: Soliciting comments through September

         20, 2017, on the Proposed Operations Implementation

         of Polygon-based Snow Squall Warnings, and Dust Storm

         Warnings and Advisory Products


Updated to accept comments through September 20, 2017


The NWS is seeking feedback on a proposal to operationally

implement high localized, polygon-based Snow Squall Warnings,

and Dust Storm Warning and Dust Advisory products on a phased

basis beginning on or about December 4, 2017.


The proposed products would be issued for a portion of a county

or counties within the warned area, as defined and depicted by

the polygon LAT/LON point pairs. Portions of counties would be

described by ordinal directions (e.g. North, Northeast, East,

Southwest, Central etc.). After an initial issuance, NWS

Weather Forecast Offices (WFO) would update the product for an

extension of area or time by issuing a new product. The NWS

Weather Forecast Office issuing the initial message would

cancel or allow it to expire when conditions no longer meet



The existing Dust Storm Warning will split into two products,

polygon-based Dust Storm Warning and zone-based Blowing Dust



The proposed operational warning products would provide three

discrete segments per the example below when the following

conditions are expected:


Snow Squall Warning:


 HAZARD...White-out conditions in heavy snow and blowing snow 

 SOURCE...Radar indicated and webcams

 IMPACT...Dangerous life-threatening travel


Dust Storm Warning:


 HAZARD...Visibility less than one-quarter mile in blowing dust

 SOURCE...Radar indicated and webcams

 IMPACT...Dangerous and life-threatening travel


The proposed operational, polygon-based Dust Advisory would be

issued when widespread or localized blowing dust suddenly

reduces visibilities to between one quarter of a mile and one

mile, resulting in hazardous travel conditions. Neither the

Emergency Alert System (EAS) nor Wireless Emergency Alerts

(WEA) would be activated when the Dust Advisory is issued. The

existing Blowing Dust Advisory will remain a zone-based



The proposed Snow Squall Warning would use the new SQ.W Valid

Time Event Code (VTEC) with an operational (O) fixed identifier

in the P-VTEC line and Warning (W) significance code. The

proposed Dust Storm Warning would use the existing VTEC code

DS.W and the proposed Dust Advisory will use the new DS.Y VTEC

code. Both of the proposed warning products would use WMO

headers for dissemination over NOAA Weather Wire Services.


NWS would request dissemination of the proposed Dust Storm

Warning via EAS using event code DSW. In some areas, and

depending on individual state EAS plans, broadcasters would

have the choice to activate EAS using the SVS Event Code for

the proposed Snow Squall Warning. NWS would broadcast the

proposed operational warnings over NOAA Weather Radio All

Hazards (NWR) and disseminate them using Specific Area Message

Encoding (SAME) and 1050 Hz warning alarm tones. NWS would also

display the warning polygon on NWS radar depictions.


NWS would also activate WEA for broadcast of the proposed

polygon-based Dust Storm Warning to WEA-capable cell phones in

the warning area. The proposed operational polygon-based DSW is

intended to better approximate the actual warning areas than do

the current zone-based Blowing Dust Warnings, which are not

depicted by polygon and can only be geo-targeted by WEA at the

county level.


The proposed Snow Squall Warning would appear on the NWS web page as well as the local WFO web pages with a

priority of number 23 and display color of medium violet red.

The proposed Dust Storm Warning and Advisory would be displayed

using the colors and priorities of the existing zone-based Dust

Storm Warning (color bisque) and Blowing Dust Advisory (color

dark khaki). 


The proposed Snow Squall Warning and Dust Storm Warning

products would be provided in Common Alerting Protocol (CAP)

format through several dissemination methods. CAP is pre-parsed

and is intended for use by the weather enterprise and other

partners. For more information on CAP and how to obtain it via

NOAAport, NWS IDP file services, in raw XML format or via a web

service API, please see the following Service Change Notice

(SCN) issued on March 24, 2017:


Additional information and examples of these proposed

operational products can be found in the Product Description

Documents here:


Dust Storm Warning/Dust Advisory:


Snow Squall Warning:


If comments are favorable, the NWS proposes to operationally

implement the proposed products beginning on or about December

4, 2017, on a phased basis to eventually include all offices.

After an initial rollout to include 8 Snow Squall Offices and 

2 Dust Storm Warning offices, all other WFOs will have the

capability to issue both products as necessary software is

installed during late winter/early spring 2018. NWS will issues

an SCN with additional information before implementation.


Please provide feedback via electronic survey at the

following links:


Snow Squall Warning:


Dust Storm Products:


If you have any questions or suggestions on the proposed

products, please contact:


For Snow Squall Warning

David Soroka 

Winter Weather Services Program Lead

NWS Severe, Fire, Public, and Winter Weather Services Branch

Silver Spring, MD 20910

Telephone: 301-427-9346



For Dust Storm Warning and Dust Advisory

Andy Horvitz

NWS Severe, Fire, Public, and Winter Weather Services Branch

Silver Spring, MD 20910

Telephone: 301-427-9357



Additional information on UGC and VTEC can be found in NWS

Instructions (NWSI) 10-1701 and NWSI 10-1703, respectively at:


National Public Information Statements are online at: