Table 3.

Different hazards and suggested lead times as estimated periods between first warning and impact onset

Type of Hydromet Hazard	Time of Occurrence	Quick or Slow Onset	Time between First Warning and Impact
Flood	Anytime	Slow	Days, weeks
Flash Flood	Anytime	Quick	Minutes, hours, day(s)
Severe Storm	Seasonal	Quick	Minutes, hours, day(s)
Tornado	Seasonal	Quick	Season
Blizzard	Seasonal	Slow	Days, week(s)
Ice Storm	Seasonal	Slow	Hours, days
Hurricane	Seasonal	Slow	Years (climatology), season, weeks, days, hours
Typhoon	Seasonal	Slow	Years (climatology), season, weeks, days, hours
Cyclone	Seasonal	Slow	Years (climatology), season, weeks, days, hours
Disease Outbreak	Anytime	Quick	Season, weeks, days
Epidemic	Anytime	Slow	Weeks, days
Pandemic	Anytime	Slow	Months, weeks
Drought	Seasonal	Slow	Months, weeks, days
Dry Spell	Seasonal	Slow	Days, weeks
El Niño / La Niña	Sub-Decadal	Slow	Season, months, weeks