Public Information Statement
Issued by NWS National HQ

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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:

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