Jefferson County - East-West Gateway Coordinating Council

A Regional Overview All-Hazard Mitigation Plan 75
Seasonal Pattern
Being in the northern hemisphere, Missouri’s geographic location has the potential to
experience severe winter weather during the months of December through February,
although winter weather has been known to also occur in mid-November and into March.
Speed Of Onset And/Or Existing Warning Systems
Winter weather typically does not hit the region without warning. The NOAA Weather
Radio, commercial radio, and television track and announce the latest winter storm
watches, warnings, and advisories. The National Weather Service sets up winter weather
warnings in stages of severity. These warnings are found below.
WIND CHILL ADVISORY:
Notice that wind chill conditions will be present and to dress appropriately
WINTER STORM WATCH:
Severe winter conditions, such as heavy snow and/or ice, are possible within
the next day or two. Prepare.
WINTER STORM WARNING:
Severe winter conditions have begun or are about to begin in your area. Stay
indoors!
BLIZZARD WARNING:
Snow and strong winds will combine to produce a blinding snow (near zero
visibility), deep drifts, and life-threatening wind chill. Seek refuge
immediately
WINTER WEATHER ADVISORY:
Winter weather conditions are expected to cause significant inconveniences
and may be hazardous. If caution is exercised, these situations should not
become life- threatening. The greatest hazard is often to motorists.
FROST/FREEZE WARNING:
Below freezing temperatures are expected and may cause significant damage
to plants, crops, or fruit trees. In areas unaccustomed to freezing
temperatures, people who have homes without heat need to take added
precautions.
Map of Hazards
Refer to Figure J45, located in the back of the Technical Appendix, for a map depicting
potential regions of Jefferson County that are susceptible to severe winter weather.
Statement of Probable Future Severity
The probable future severity of severe winter weather will most likely be similar to the
climatologic past. Based on the climatic history of Jefferson County, winter weather and