Winter WeatherWinter WeatherSituational AwarenessSituational Awareness

Jeff Last / Todd Shea Jeff Last / Todd Shea NOAA National Weather ServiceNOAA National Weather ServiceGreen BayGreen Bay

““The Catch…”The Catch…”

The SetupThe Setup• Major airmass changeMajor airmass change• Forecast of dangerous wind chillsForecast of dangerous wind chills

Midwest Weather Warnings – Issued January 29, 2008Midwest Weather Warnings – Issued January 29, 2008

The SetupThe Setup• Wind Chill WarningsWind Chill Warnings

– Issued evening before west of Miss. RiverIssued evening before west of Miss. River– Issued 2:09 a.m. most of western WIIssued 2:09 a.m. most of western WI

• Plenty of media coveragePlenty of media coverage• Wind Chill values of -30 to -40 FWind Chill values of -30 to -40 F

La Crosse, WI ConditionsLa Crosse, WI Conditions

Time Temperature Wind Speed Wind Chill

12:00 a.m. -9 18 -33

1:00 a.m. -10 21 -36

2:00 a.m. -9 15 -31

3:00 a.m. -1 15 -21

4:00 a.m. +1 12 -16

5:00 a.m. -2 16 -23

6:00 a.m. -2 15 -22

7:00 a.m. -2 13 -21

8:00 a.m. -1 10 -17

9:00 a.m. -5 13 -24

January 30, 2008January 30, 2008

Automated ObservationAutomated ObservationSystem!System!

Hourly TemperaturesHourly Temperatures

Time La Crosse Winona Rochester Sparta

12:00 a.m. -9 -9 -11 -8

1:00 a.m. -10 -9 -11 -8

2:00 a.m. -9 -9 -12 -9

3:00 a.m. -1 -8 -12 -9

4:00 a.m. +1 -9 -12 -9

5:00 a.m. -2 -9 -13 -9

6:00 a.m. -2 -11 -13 -11

7:00 a.m. -2 -9 -13 -11

8:00 a.m. -1 -9 -13 -11

9:00 a.m. -5 -8 -12 -8

January 30, 2008January 30, 2008

A Second ChanceA Second Chance

How to prevent thisHow to prevent thisin the future...in the future...

The National Weather ServiceThe National Weather Service• 24 hour operations24 hour operations• 22 staff members22 staff members• 2-3 per shift2-3 per shift

– More coverage during More coverage during active weatheractive weather

Continuous Weather Continuous Weather Watch !Watch !

MinneapolisMinneapolis

Green Bay

MN

IA Milwaukee/SullivanMilwaukee/Sullivan

DuluthDuluth

Green BayGreen Bay

NWS Service Areas in WisconsinNWS Service Areas in Wisconsin

La CrosseLa Crosse

Five NWS offices serve Five NWS offices serve the 72 counties in the 72 counties in Wisconsin.Wisconsin.

NWS DutiesNWS Duties• Severe Weather / HazardsSevere Weather / Hazards• Public ForecastsPublic Forecasts• Aviation ForecastsAviation Forecasts• HydrologyHydrology• Fire WeatherFire Weather• Climate / Data CollectionClimate / Data Collection• NOAA Weather RadioNOAA Weather Radio• Research / TrainingResearch / Training• Public Service / EducationPublic Service / Education

NWS EquipmentNWS Equipment• Weather Obs StationsWeather Obs Stations• SatellitesSatellites• Computers (many!)Computers (many!)• Doppler RadarDoppler Radar• Weather BalloonsWeather Balloons• Wind ProfilersWind Profilers• River GaugesRiver Gauges• NOAA NOAA

Weather RadioWeather Radio

Forecast “Packages”Forecast “Packages”• Two main forecasts setsTwo main forecasts sets

– 4:00 a.m. and 4:00 p.m.4:00 a.m. and 4:00 p.m.• Continuous updatesContinuous updates

– Continuous “weather watch”Continuous “weather watch”• Include outlooks, watches, Include outlooks, watches,

warnings and advisorieswarnings and advisories• Forecasts are collaboratedForecasts are collaborated

– With other NWS offices & mediaWith other NWS offices & media

NWS forecasters analyze NWS forecasters analyze current weather conditions current weather conditions across Wisconsin, the U.S., across Wisconsin, the U.S., and North America to gain an and North America to gain an understanding of what is understanding of what is happening now.happening now.

Forecasters then review the Forecasters then review the output from the numerical output from the numerical models and begin formulating models and begin formulating a seven-day forecast for the a seven-day forecast for the forecast area.forecast area.

Putting Together the ForecastPutting Together the Forecast

Finally, forecasters use Finally, forecasters use the Interactive Forecast the Interactive Forecast Preparation System (IFPS) Preparation System (IFPS) to “draw” sensible to “draw” sensible weather, creating a weather, creating a digital weather database.digital weather database.

Putting Together the ForecastPutting Together the Forecast

IFPS then generates text, IFPS then generates text, graphics, and charts from graphics, and charts from the “gridded” data, and the “gridded” data, and makes the data available makes the data available to anyone “on demand.”to anyone “on demand.”

Putting Together the ForecastPutting Together the Forecast

Putting Together the ForecastPutting Together the Forecast

Putting Together the ForecastPutting Together the Forecast

The ForecastThe Forecast• AccuracyAccuracy

– Perfect? No…but perhaps better than you thoughtPerfect? No…but perhaps better than you thought– What is your weather source?What is your weather source?– How closely do you track forecasts?How closely do you track forecasts?

• Weather is continuous – updates are neededWeather is continuous – updates are needed• Each forecast has a confidence factorEach forecast has a confidence factor

– Can you trust high confidence forecasts?Can you trust high confidence forecasts?– Can you trust warnings?Can you trust warnings?

• ““Yes” to both questions – and use them to Yes” to both questions – and use them to your advantage your advantage

Tiered ApproachTiered Approach

OUTLOOK WATCHADVISORY

WARNING

Up to three days

ahead

Up to three days

ahead

Up to a week ahead

Up to a week ahead

Many hours ahead

Many hours ahead

““Ready, Set, Go”Ready, Set, Go”

HeadlinesHeadlines• OutlookOutlook (Initial heads up) (Initial heads up)• WatchWatch

– Conditions are favorable but still may not happenConditions are favorable but still may not happen– Issued when 50% likelihoodIssued when 50% likelihood

• AdvisoryAdvisory– Expected to occur but if caution is exercised, should not become life Expected to occur but if caution is exercised, should not become life

threateningthreatening– Issued when 80% likelihoodIssued when 80% likelihood

• WarningWarning– Expected to occur and could be life threateningExpected to occur and could be life threatening– Highest dangerHighest danger– Issued when 80% likelihoodIssued when 80% likelihood

Hazardous Weather OutlookHazardous Weather Outlook• Issued by 6 am each dayIssued by 6 am each day• Updated as neededUpdated as needed• Text formatText format• Available via:Available via:

– E-mailE-mail– InternetInternet– NOAA Weather RadioNOAA Weather Radio

HAZARDOUS WEATHER OUTLOOKNATIONAL WEATHER SERVICE GREEN BAY WI600 AM CDT FRI JAN 17 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL AND NORTHEAST WISCONSIN.

.DAY ONE...TODAY AND TONIGHT

HEAVY SNOW IS EXPECTED LATER THIS AFTERNOON AND THIS EVENING. 3 TO 6 INCHES WILL FALL BY MIDNIGHT.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

COLD AIR WILL POUR INTO THE REGION THIS WEEKEND. WIND CHILLS COULD FALL TO 25 TO 30 BELOW ZERO BY SUNDAY MORNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ASKED TO CONTACT THE NATIONAL WEATHER SERVICE WITH SNOWFALL TOTALS TONIGHT.

Winter WatchesWinter Watches• Winter Storm WatchWinter Storm Watch

– Most common, by farMost common, by far– Issued for heavy snow or ice storm potentialIssued for heavy snow or ice storm potential

• Lake Effect Snow WatchLake Effect Snow Watch• Blizzard WatchBlizzard Watch• Wind Chill WatchWind Chill Watch

Watches are issued when confidence reaches Watches are issued when confidence reaches 50%50% likelihood likelihood

Winter AdvisoriesWinter Advisories• Winter Weather AdvisoryWinter Weather Advisory

– For snow (3-5”)For snow (3-5”)– For mixed precipitationFor mixed precipitation– For blowing snowFor blowing snow

• Lake Effect Snow AdvisoryLake Effect Snow Advisory• Wind Chill AdvisoryWind Chill Advisory• Freezing Rain AdvisoryFreezing Rain Advisory• Dense Fog AdvisoryDense Fog Advisory

Advisories are issued when confidence reaches Advisories are issued when confidence reaches 80%80% likelihood likelihood

Winter WarningsWinter Warnings• Blizzard WarningBlizzard Warning

– Snow and blowing that frequently reduces visibility to Snow and blowing that frequently reduces visibility to less than ¼ mile with very strong windsless than ¼ mile with very strong winds

• Winter Storm WarningWinter Storm Warning– For heavy snow (6”+)For heavy snow (6”+)– For heavy mixed precipFor heavy mixed precip– For heavy snow and blowing snowFor heavy snow and blowing snow

• Lake Effect Snow WarningLake Effect Snow Warning• Ice Storm WarningIce Storm Warning• Wind Chill WarningWind Chill Warning

Warnings are issued when confidence reaches Warnings are issued when confidence reaches 80%80% likelihood likelihood

Wind ChillWind ChillWind Chill Advisory:Wind Chill Advisory:Wind chills of 20 below orWind chills of 20 below orcolder with winds around colder with winds around 5 mph or stronger.5 mph or stronger.

Wind Chill Warning:Wind Chill Warning:Wind chills of 35 below orWind chills of 35 below orcolder with winds aroundcolder with winds around5 mph or stronger.5 mph or stronger.

Note: These are slightly changedNote: These are slightly changedcriteria from last year.criteria from last year.

Briefing ProcessBriefing Process• Check Hazardous Weather OutlooksCheck Hazardous Weather Outlooks• Listen / watch local mediaListen / watch local media• Go to Go to weather.govweather.gov

– Check map for current advisoriesCheck map for current advisories– Click on map for detailsClick on map for details– Check “Top News” for additional infoCheck “Top News” for additional info– Check current weather observationsCheck current weather observations– Radar imagery is also availableRadar imagery is also available

• If all else fails, you can call your local NWS office, If all else fails, you can call your local NWS office, but not best option.but not best option.– Busiest time of day for NWS office is often between Busiest time of day for NWS office is often between

2 a.m. and 6 a.m.2 a.m. and 6 a.m.

weather.govweather.gov

/greenbay/greenbay

/lacrosse/lacrosse

/milwaukee/milwaukee

Web Page DemonstrationWeb Page Demonstration

weather.govweather.gov//greenbaygreenbay

weather.govweather.gov//lacrosselacrosse

weather.govweather.gov//milwaukeemilwaukee