WARNING and ADVISORY CRITERIA WFO Louisville, KY (LMK) 2014

Warning Type and Criteria

Blizzard Sustained winds or frequent gusts ≥ 35 mph and considerable S/BS with vsbys ≤ 1/4 mi for 3-hr period Any combo of snow, IP, or ZR averaging ≥ 4”/12 hrs; for snow, issue a “ warning for heavy Winter Storm snow” for average amts ≥ 4”/12 hrs (e.g., 3-5”, 3-6”, 4-8”); think impact-can issue wrng if close to criteria Ice (ZR) accum ≥ 1/4” that is a potential hazard to life or property; ZR is the only precip type expected Wind Chill WC ≤ -25 °F and wind speed close to or above 10 mph Freeze Temps ≤ 30 °F for at least 2 hrs at ≥ 3 obs sites; cease freezes after Election Day unless no freeze to date High Wind Sustained winds ≥ 40 mph for ≥ 1 hr or ≥ 58 mph for any duration Excessive Heat Max heat index ≥ 110 °F for about ≥ 3 hrs (no night criteria) Red Flag 10-hour fuels ≤ 8%, RH < 25%, 20 foot winds > 15 mph for several hours Severe Tstm Reported or radar indicated tstm with ≥ 1 inch hail or winds ≥ 58 mph, or storm that may cause damage Reported or radar indicated tstm with signif mesocyclone & low-level rotation, or squall line mesovortices Flash High rainfall rates, amts near/exceeding FFMP guidance, and/or reported flowing water over roads

Advisory Type and Criteria

Any combo of snow, IP, or ZR averaging 1-4”/12 hrs; for snow, issue a “ for snow” Winter Weather for amts of 1-4" in 12 hrs (e.g., around 1”, 1-2”, 1-3”, 2-4”); think impact-can issue advsry if close to criteria Freezing Rain Ice (ZR/ZL) accumulations < 1/4” not deemed a hazard to life or property Wind Chill WC -10 °F to -24 °F & wind speed close to or above 10 mph Frost Widespread frost expected with air temps ≤ 35 °F for at least 2 hr at ≥ 3 obs sites and wind speeds < 6 mph Wind Sustained winds 30 mph for ≥ 1 hr, or for gusts ≥ 40 mph (local decision) for any duration Heat Max heat index ≥ 105 °F for about ≥ 3 hrs (no night criteria) Dense Reported visibilities ≤ 1/4 mi for ≥ 2 hrs Flood Heavy rain expected to cause low-impact/low-lying flooding, significant water ponding, etc.

The above criteria are guidelines with forecaster judgment to do what’s best for the customer. Think not only criteria, but IMPACT as well. Under certain conditions, CR WFOs may lower these criteria for a particular event or due to expected impact. Review the LMK Winter Weather and Flood Policy statements on the intranet for more details.