- Hydrologic Outlook for San Bernadino County-Upper Colorado River Valley County, California
- Hydrologic Outlook issued September 28 at 11:33AM PDT by NWS
- Effective: Monday, October 1, 2018 at 11 a.m.
- Expires: Saturday, September 29, 2018 at 6 a.m.
...Heavy Rain Possible Sunday night through Tuesday...
* What: Heavy rain. Widespread amounts of 1 to 2 inches with
localized amounts up to 4 inches are possible.
* Impacts: Localized flooding causing some roads to be impassable.
Local washes and waterways may exit their banks and impact
* Confidence: High on potential for rain. Medium on timing,
locations, and amounts.
* Where: Across the Southwest US, including south-central and
southwest Arizona and southeast California. This includes
Phoenix, Yuma, Globe, and Casa Grande in Arizona, and the
Imperial Valley in California.
* When: Beginning Sunday night and continuing through Tuesday.
* Summary: Abundant moisture associated with a tropical system
will move northward into the Southwest US. Meanwhile, a low
pressure system will move through California and the Four
Corners states. This setup will cause widespread rain to
develop. Rain rates may be quite high at times, in excess of 2
to 4 inches per hour, which will have the potential to cause
localized flooding. Due to the duration of the event, the
potential exists for more widespread flooding to occur.
Continue to monitor forecasts for updates as this situation
unfolds. Follow NWS Phoenix on Facebook at
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