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Heavy Rainfall to Bring Flooding Threat to California; Heavy Snow in the Sierra

A strong atmospheric river will bring heavy rainfall to California through the holiday week. The heaviest rainfall is expected on Wednesday in the Los Angeles Basin. Flash and urban flooding is possible. A prolonged heavy snowfall is expected in the Sierra Nevada from the atmospheric river, raising concerns for major snow‐load impacts. Travel may be difficult to impossible over the passes. Read More >

Are you planning an outdoor activity within the next few days? If so, and if thunderstorms are in the forecast, then you should try to determine the expected potential for lightning that could threaten you and others. Paying attention to the latest forecast and being flexible to change your plans to stay safe from lightning is always a good action to take.

To help you stay safe from lightning threats, the Lightning Potential Index (LPI) was developed by the National Weather Service as a planning tool. The experimental LPI is routinely generated for areas of western Colorado and eastern Utah that shows you where and when cloud-to-ground lighting is expected out to 60 hours into the future. More specifically, the LPI provides lightning expectations in three-hour increments and is updated every 3 hours to give you the very latest forecast information.

You can find the Lightning Potential Index forecasts from the “Forecasts” drop-down menu on the National Weather Service’s Grand Junction Forecast Office website, as shown below.

Please check it out and let us know how the LPI works for you! Comments can be provided to our forecast office email address: wxgjt@noaa.gov

Click here for the latest Lightning Potential Index forecasts.