NOUS41 KWBC 241426 AAA
Public Information Notice, Comment Request: Amended
National Weather Service Headquarters Washington DC
1027 AM EDT Thu Sep 26 2013
-Family of Services
-NOAA Weather Wire Service
-Emergency Managers Weather Information Network
Other NWS Partners and NWS Employees
FROM: Eli Jacks
Chief, Fire and Public Weather Services Branch
SUBJECT: Amended: Soliciting Comments Until April 15, 2014,
on an Experimental Scaled Predictive Ice Storm
Aftermath Index at Select NWS Weather Forecast Offices
Amended to extend comment period through April 15, 2014, and to
add 5 additional participating WFOs (Table 1)
NWS is accepting comments from through April 15, 2014, on an
experimental Scaled Predictive Ice Storm Aftermath (SPIA) Index.
Select NWS Weather Forecast Offices (WFOs) (Table 1) will
produce Web graphics depicting the potential impact of freezing
rain and wind on exposed electrical systems to enhance their
decision support services.
Current NWS Ice Storm Warnings are issued based on forecast ice
accumulation only, typically one quarter of an inch or greater.
The combined effect of ice and wind, which more realistically
describes damage potential, is not formally set as warning
By using the SPIA scaled index, NWS should be able to provide a
better understanding of ice storm impact potential to local,
state, and federal response entities. The potential impacts are
scaled from 0 to 5 and suggest potential electrical outage
coverage and duration.
Until now, the NWS has not attempted to routinely quantify the
impact of ice storms. The use of this scaled index will allow
the NWS to evaluate the potential of providing these specifics.
For example, a level 5 ice storm would be defined as one causing
catastrophic damage to entire exposed utility systems, including
both distribution and transmission networks. Outages could last
several weeks in some locations.
Graphics showing forecast index values will be available as part
of the routine forecast provided online for the following WFOs:
Table 1: Participating WFOs and url:
WFO Tulsa (TSA)
WFO Little Rock (LZK)
WFO Jackson (JAN)
WFO Nashville (OHX)
WFO Memphis (MEG)
WFO Norman (OUN)
WFO Springfield (SGF)
WFO Pleasant Hill (EAX)
WFO St. Louis (LSX)
WFO Paducah (PAH)
More information regarding the SPIA index is online in a Product
During this comment period, a proactive effort will be made to
educate users and partners of the product availability and use.
At the end of the comment period, the NWS will make a decision
on whether to transition the experimental SPIA Index to operational
status. The experimental SPIA Index may also be considered for
use at other WFOs and NWS Regions.
For more information please contact:
National Weather Service
Tulsa, OK 74128
National Public Information Notices are online at: