Heavy Rain and Thunderstorms in the Plains; Snow in the Northern Rockies; Heavy Rain in Guam

A storm system moving over the Rockies today will bring marginal risks for excessive rainfall and severe thunderstorms from parts of New Mexico into western South Dakota. Heavy snow expected from northwestern Wyoming into southern Montana. Ongoing heavy showers and thunderstorms from Invest 96W could result in localized flash flooding, particularly in central or southern Guam early this morning. Read More >

General (lightning)

Biggest takeaway:
This is a routine occurrence/hazard that needs a plan - otherwise, you are putting your people's lives at risk. When Thunder Roars - Go Indoors (or into your vehicle). Nearly all lightning deaths occur outside - from people disregarding their risk, or thinking they have a few minutes more. The most deadly strikes are often the first few before the rain begins.

Warning/Trigger for Plan:
There is no NWS warning for lightning threat, but nature has its own warning - thunder.

Advance Notice/Time to Activate & Accomplish Your Planned Response:
Typically 5-30 minutes

Frequency: ~ 20 times/year at various time of day & night

Lightning threat is all about level of risk. Anything past what is listed below as safe near a thunderstorm increases your risk.
If you can hear thunder, you are in danger of being struck outdoors.
Nearly all lightning deaths occur outdoors.
Staying dry is not the same as being safe from lightning.
Some charge from a nearby strike can be carried through wiring & plumbing. To be extra safe, avoid using corded items, or showers/sinks during thunderstorms.
What is Safe?:
- Fully enclosed, permanent building
  - Not roofed, but open shelters (like gazebos)
  - Not fabric covered, metal framed pavilions
  - Shelter from the rain is not the same as shelter from lightning
- Hardtop (non-convertible) Vehicles
- "When Thunder Roars, Head Indoors"
- Shelter at first rumble of thunder
- Shelter until 30 mins after last rumble of thunder
- Anything less than the above increases risk.
At a minimum, make all aware of the risk, & what they can do to lessen their own risk individually.
Safety References: