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 >

Porcupine Slide Banner

Forecast Banner

Summary: Inclement and cooler temperatures are expected through early next week. Heavy rain is possible especially Sunday and Monday. Mudslides (from heavy rainfall) and lightning will be hazards over the next few days.

Precipitation Amounts:

A half (0.50) to one inch (1.25) of rain is expected between Friday through Tuesday. The heaviest amounts are expected Sunday and Monday.

Temperatures:

Highs: Mid 60s through early next week.
Lows: Around 45 degrees over the next few nights.

For more in-depth forecast information at the slide location, click on this link: https://forecast.weather.gov/MapClick.php?marine=0&site=RIW&zmx=1&zmy=1&FcstType=text&lat=43.02738&lon=-110.80767&Submit=Submit#.WrF_Q5oh3AW

River Stages Banner

River Gauge Stages (Hydrographs) near Porcupine Slide - Click on Graphs to Enlarge
Current Stage for Grey's River above the Porcupine Slide	Current Stage for Grey's River below the Porcupine Slide

Snake River near Alpine (Current Stage & Forecast)	Grey's River above Palisades Reservoir (Current Stage & Forecast)

2 and 4-day liquid (rain and melted snow) total
2 and 4-day total snowfall
Highs and lows over the next couple of days
The 6 to 10 and 8 to14 day temperature and precipitation outlooks

48 Hour Liquid Precipitation	48 Hour Snow Accumulation	Day 1 Maximum Temperature	Day 2 Maximum Temperature

96 Hour Liquid Precipitation	96 Hour Snow Accumulation	Day 1 Minimum Temperature	Day 2 Minimum Temperature

6-10 Day Temp Outlook	6-10 Day Precipitation Outlook	8-14 Day Temp Outlook	8-14 Day Precipitation Outlook

Want to track the storm? Here are the local and regional radar loops:

Current Radar - Click Thumbnails To Enlarge

Northern Rockies Radar	Riverton Radar	Pocatello, ID Radar

SnoTel Graphs - Click to Enlarge Graphs below show: â–º Current Snow Water Equivalent (SWE) and from 2017 â–º Average/Median SWE through the year (shows when the snow typically melts) â–º SWE in 2018 compared to years with highest SWE
Map of Area SnoTels and 2018 SWE percent of 1981-2010 Average

Willow Creek SnoTel

	2018 Compared to Highest Years (as of 5/9/2018)
Triple Peaks SnoTel

	2018 Compared to Highest Years (as of 5/9/2018)
Cottonwood Creek/Lake SnoTel

	2018 Compared to Highest Years (as of 5/9/2018)