The National Weather Service office in Pocatello, Idaho, issued a Flash Flood Warning on September 18 at 10:44 AM MDT. The warning is in effect until 1:45 PM MDT and covers three counties in eastern Idaho: Jefferson, Madison, and Blaine.
A flash flood warning means flooding is already happening or is about to happen very soon – this is not a watch or a possibility, it’s an active situation. Flash floods can develop within minutes of heavy rainfall, sending fast-moving water into streets, low-lying areas, creeks, and normally dry washes. The communities within and around these three counties – including areas near Idaho Falls, Rexburg, and the Wood River Valley – should treat this as an immediate concern.
What You Might Notice
Residents in the warned areas may see rapidly rising water on roads, in ditches, and along small streams and creeks. Water can cover roads that look passable – it only takes about six inches of moving water to knock a person down and roughly a foot to carry away a vehicle. If you are driving and encounter water over the roadway, turn around. Do not attempt to drive or walk through it.
What You Should Do Now
If you are in Jefferson, Madison, or Blaine County: move to higher ground if you are in a low-lying area, near a creek, or in a flood-prone spot. Avoid driving unless necessary, and never cross flooded roads. Keep a phone charged and tuned to local alerts, since additional warnings or extensions may be issued if heavy rain continues. The warning is currently scheduled to expire at 1:45 PM MDT, but NWS may extend it depending on conditions.
Conditions can change quickly with flash flooding, so treat the next few hours as a time to stay put and stay aware rather than travel. This alert is based on official data from the National Weather Service (NWS) office in Pocatello, Idaho.
Frequently Asked Questions
What should I do right now?
If you're in Jefferson, Madison, or Blaine County, move away from low-lying areas, creeks, and washes, and stay off the roads if possible. Never drive or walk through floodwater – turn around and find another route.
How long will this warning last?
The warning is in effect until 1:45 PM MDT on September 18. The National Weather Service may extend or expand it if heavy rainfall continues, so keep monitoring local alerts.
Is a flash flood warning different from a flood watch?
Yes. A watch means conditions are favorable for flooding, while a warning means flooding is occurring or imminent. This is a warning, so the threat is active and immediate.
Do I need to evacuate my home?
Only if you are in a flood-prone or low-lying area, near a waterway, or if local officials instruct you to leave. In most cases, moving to higher ground within or near your home and avoiding travel is sufficient – follow guidance from local emergency management.
Keep tracking this:
Source: National Weather Service (NWS)
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Sky & Solar Conditions at the Time
Moon: First Quarter (48% illuminated), in Sagittarius.
Notable planetary angles: Mercury opposite Saturn (180°), Sun sextile Mars (61°), Sun square Moon (88°).
Concurrent space weather: planetary Kp index 0.7; strongest recent solar flare: nothing notable.
This is a factual snapshot, not a claim of cause and effect – researchers are divided on whether lunar, planetary or solar factors influence seismic or weather activity. It’s included so readers can track the pattern for themselves over time.
