NWS Winter Weather Products and Upcoming

Chat Changes

Gary Woodall

WFO Fort Worth/Dallas, TX

Winter 2008-2009

Winter Wx Products – Outlook Outlooks – 3-7 day advance notice of

winter event which has the potential to threaten life/property.

Included in Hazardous Weather Outlook and Special WX Statement.

HWO - FLUS44 KFWD SPS - WWUS84 KFWD Updated information every 12 hours. Continue outlook info until watch issued

or threat diminishes.

Winter Wx Products - Watch

Watches– 50% or greater chance of event exceeding warning criteria in 2nd or 3rd forecast period (SPS Otherwise).

Occasionally (rarely) out to 4th period. WSWFWD (WWUS44 KFWD) updated

every 8-12 hours or if conditions change. Issued as “Winter Storm Watch”. Continued until warning issued, advisory

issued, or threat diminishes.

Winter Wx Products - Warnings

Warnings – likelihood (80%) of event exceeding warning criteria in first 1-2 forecast periods.

Occasionally (rarely!) out to 3rd period. WSWFWD (WWUS44 KFWD) updated

every 6-8 hours. Continued until event ends or threat

diminishes (warning cancelled).

Warning Criteria Heavy Snow – 4+” in 12h, 6+” in 24h. Blizzard – 35+ mph wind, vsby < ¼ mi,

for 3+ hours. Ice storm – ¼ inch ZR accumulation. Heavy sleet – ½ inch IP accumulation. Combination of events with one meeting

warning criteria. We may factor impacts, response into

borderline advisory/warning decisions

Winter Wx Products - Advisories

Advisories – likelihood (80%) of event in first 1-2 forecast periods.

Event will cause significant inconvenience or threat if precautions not followed.

WSWFWD (WWUS44 KFWD) updated every 6 - 8 hours.

Continued until event ends or threat diminishes.

Advisory Criteria Snow – 1-3” in 12 hours. Blowing Snow – vsby < ¼ mile. Freezing Rain – less than ¼ inch. Sleet – less than ½ inch accumulation. Freezing Drizzle – light accumulation. Wind Chill – values at or below 0 F. Combination of elements, none of which

meets warning criteria.

Warning/Advisory Wording Ice storm warning Winter storm warning Freezing rain advisory Winter weather advisory “...winter storm warning for <element>...” “...winter weather advisory for <xxx>...” Warning/advisory segments will discuss the

element(s) in more detail.

Non-Precip Products - NPWFWD

High Wind Warning – sustained winds 40 mph or stronger, frequent gusts to 58+ mph, for 1 hour or longer.

Wind Advisory – sustained winds 25+ mph for 2 hours or longer (frequent gusts 35+?).

Dense Fog Advisory – widespread or localized fog reducing visibilities to 1/4 mile or less.

Freeze Warning – first freeze of season or sig freeze after a warm spell.

Frost Advisory – first frost of season, frost after growing season starts.

Segmented Format Winter WX products continue with

segmented format Cancellations Warnings Advisories Watches

Headline/overview at top of product. Specific headlines, review of specific

impacts in each segment. Each segment will briefly “Tell the story”.

Product Suite WSWs should discuss synoptic scale

environment. Short Term Fcsts – Every 1-3 hours,

discusses meso/sub-synoptic features, precip rates.

SPSs to cancel outlooks. SPS/sig WX advisory can be used to

discuss sig precip areas (CG threat embedded in stratiform pcpn, bands of heavy snow, etc.).

Other Considerations Primary thoughts in Area Forecast

Discussion (FXUS64 KFWD), IEM/NWS Chat for collaboration.

Meet-me conference call if necessary. Dynamic web headlines as event evolves. Graphical images to depict

warning/advisory areas, potential impacts. You are welcome to use images/info!

IEM Chat to NWS Chat NWS has hired Daryl Herzmann,

incorporating IEM Chat. Chat transition to NWS by mid January. Advantage: Multiple redundant backup

servers. Advantage: 24/7 server support. Disadvantage: Re-registration, will

need to take short (10 minute) “training”. Disadvantage: 12-character password,

may need to update periodically.

IEM Chat to NWS Chat Gaim/Pidgin will still work as chat

software. “Bot” for injecting our hazardous

weather products will be in NWS Chat. Broadcast messages through IEM

system outlining changes. Please let me know of any possible

adverse impacts!

Summary A suite of products is available to

convey winter weather threats. The winter weather product suite should

be more streamlined in ’08-09. Changes are coming to the IEM/NWS

Chat system. We will use all available methods to

collaborate during winter weather events.

Questions?