Jefferson County, MO Weather Alerts
Every National Weather Service alert issued for Jefferson County, Missouri, pushed to your phone within moments — county code MOC099, forecast zone MOZ065. Free with StormCast.
Download on Google PlayHow the NWS identifies Jefferson County
These are the identifiers the National Weather Service uses when it issues a warning here. StormCast watches MOC099 directly rather than matching on place names, which is why an alert arrives whether you are in Arnold or anywhere else in the county.
NWS County Code
MOC099
Forecast Zone
MOZ065
Forecast Office
St. Charles (LSX)
Radar Station
KLSX
Towns covered in Jefferson County
An NWS alert for Jefferson County applies to all 19 of these communities. You do not need a separate alert for each one.
River gauges in and around Jefferson County
StormCast tracks 5 gauges near Jefferson County. Set a flood-stage alert on any of them to get notified before the water reaches you.
Current conditions
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Alert types issued for Jefferson County
Tornado
Tornado Warning, Tornado Watch, Tornado Emergency and Severe Thunderstorm Warning.
How tornado alerts work →Flooding
Flash Flood Warning, Flood Watch, Flood Advisory and River Flood Warning.
How flood alerts work →Winter
Winter Storm Warning, Ice Storm Warning, Blizzard Warning and Winter Weather Advisory.
Winter warnings explained →Fire Weather
Red Flag Warning and Fire Weather Watch when conditions favor rapid fire spread.
Fire weather alerts →Heat & Cold
Excessive Heat Warning, Heat Advisory, Freeze Warning and Frost Advisory.
Frost & freeze alerts →Jefferson County weather alert questions
Which NWS forecast zone is Jefferson County in?
Jefferson County, Missouri is NWS county code MOC099 and forecast zone MOZ065. Alerts for it are issued by the St. Charles (LSX) Weather Forecast Office, and the nearest NEXRAD radar is KLSX.
Which towns in Jefferson County are covered?
All of them. NWS alerts are issued at the county and zone level, so a warning for Jefferson County covers every community inside it, including Arnold, Barnhart, Cedar Hill, Crystal City, De Soto, Dittmer, Festus, Fletcher, Hematite, Herculaneum, High Ridge, Hillsboro, House Springs, Imperial, Kimmswick, Liguori, Mapaville, Morse Mill and Pevely.
Are there river gauges in Jefferson County?
Yes — StormCast monitors 5 river gauges in and around Jefferson County, including Mississippi River at Herculaneum, Big River at Byrnesville, Joachim Creek at DeSoto. You can set a flood-stage alert on any of them and get a push notification when the water rises.
How fast are alerts for Jefferson County delivered?
StormCast polls the NWS alert feed every 30 seconds. When a warning is issued for MOC099, the push notification goes out within moments — even with your screen off.