Winter Weather Situational Awareness Jeff Last / Todd Shea NOAA National Weather Service Green Bay

“The Catch…”

The Setup Major airmass changeMajor airmass change Forecast of dangerous wind chillsForecast of dangerous wind chills Midwest Weather Warnings – Issued January 29, 2008

The Setup Wind Chill WarningsWind Chill Warnings –Issued evening before west of Miss. River –Issued 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 Conditions TimeTemperatureWind SpeedWind Chill 12:00 a.m :00 a.m :00 a.m :00 a.m :00 a.m :00 a.m :00 a.m :00 a.m :00 a.m :00 a.m January 30, 2008 Automated Observation System!

Hourly Temperatures TimeLa CrosseWinonaRochesterSparta 12:00 a.m :00 a.m :00 a.m :00 a.m :00 a.m :00 a.m :00 a.m :00 a.m :00 a.m :00 a.m January 30, 2008

A Second Chance How to prevent this in the future...

The National Weather Service 24 hour operations24 hour operations 22 staff members22 staff members 2-3 per shift2-3 per shift –More coverage during active weather Continuous Weather Watch !

Minneapolis Green Bay MN IA Milwaukee/Sullivan Duluth Green Bay NWS Service Areas in Wisconsin La Crosse Five NWS offices serve the 72 counties in Wisconsin.

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

Forecast “Packages” Two main forecasts setsTwo main forecasts sets –4:00 a.m. and 4:00 p.m. Continuous updatesContinuous updates –Continuous “weather watch” Include outlooks, watches, warnings and advisoriesInclude outlooks, watches, warnings and advisories Forecasts are collaboratedForecasts are collaborated – With other NWS offices & media

NWS forecasters analyze current weather conditions across Wisconsin, the U.S., and North America to gain an understanding of what is happening now. Forecasters then review the output from the numerical models and begin formulating a seven-day forecast for the forecast area. Putting Together the Forecast

Finally, forecasters use the Interactive Forecast Preparation System (IFPS) to “draw” sensible weather, creating a digital weather database. Putting Together the Forecast IFPS then generates text, graphics, and charts from the “gridded” data, and makes the data available to anyone “on demand.”

Putting Together the Forecast

The Forecast AccuracyAccuracy –Perfect? No…but perhaps better than you thought –What is your weather source? –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 warnings? “Yes” to both questions – and use them to your advantage“Yes” to both questions – and use them to your advantage

Tiered Approach OUTLOOK WATCH ADVISORY WARNING Up to three days ahead Up to a week ahead Many hours ahead “Ready, Set, Go”

Headlines Outlook (Initial heads up)Outlook (Initial heads up) WatchWatch –Conditions are favorable but still may not happen –Issued when 50% likelihood AdvisoryAdvisory –Expected to occur but if caution is exercised, should not become life threatening –Issued when 80% likelihood WarningWarning –Expected to occur and could be life threatening –Highest danger –Issued when 80% likelihood

Hazardous 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: – –Internet –NOAA Weather Radio HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREEN BAY WI 600 AM CDT FRI JAN 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 Watches Winter Storm WatchWinter Storm Watch –Most common, by far –Issued 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 50% likelihood

Winter Advisories Winter Weather AdvisoryWinter Weather Advisory –For snow (3-5”) –For mixed precipitation –For 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 80% likelihood

Winter Warnings Blizzard WarningBlizzard Warning –Snow and blowing that frequently reduces visibility to less than ¼ mile with very strong winds Winter Storm WarningWinter Storm Warning –For heavy snow (6”+) –For heavy mixed precip –For 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 80% likelihood

Wind Chill Wind Chill Advisory: Wind chills of 20 below or colder with winds around 5 mph or stronger. Wind Chill Warning: Wind chills of 35 below or colder with winds around 5 mph or stronger. Note: These are slightly changed criteria from last year.

Wind Chill

TimeTemperatureWind SpeedWind Chill 6:00 a.m.-43 7:00 a.m.-40 8:00 a.m.-33 9:00 a.m :00 a.m :00 a.m :00 p.m :00 p.m.43 2:00 p.m :00 p.m.63

Briefing Process Check Hazardous Weather OutlooksCheck Hazardous Weather Outlooks Listen / watch local mediaListen / watch local media Go to weather.govGo to weather.gov –Check map for current advisories –Click on map for details –Check “Top News” for additional info –Check current weather observations –Radar imagery is also available If all else fails, you can call your local NWS office, but not best option.If all else fails, you can call your local NWS office, but not best option. –Busiest time of day for NWS office is often between 2 a.m. and 6 a.m.

weather.gov/greenbay /lacrosse /milwaukee

Web Page Demonstration weather.gov / greenbay weather.gov / lacrosse weather.gov / milwaukee