Predictive Services Climate and Significant Fire Potential Outlook

Predictive Services Climate and Significant Fire Potential Outlook st Tuesday June 1 2021

Temperature Forecast vs Observed: May 2021 Observed in May Temp Outlook for May Characterization: Temperature for the Cascades of Oregon and Washington was slightly above normal.

Rainfall Forecast vs Observed: May 2021 Observed in May Precip Outlook for May Characterization: Much of the region was much drier than normal in May except for Washington Cascades.

Climate Since January 1 st 2021 Temperature Departure from normal Precipitation Percent of normal

Basin Snow Water Equivalent Characterization: Snowpack is declining rapidly in Oregon. Washington snowpack remains generally at or above normal with some exceptions east of the Cascades.

U. S. Drought Monitor Mar 2 nd 2021 May 25 th 2021

ENSO Status: La Niña has ended May 13 th Synopsis: La Niña has ended, with ENSO-neutral likely to continue through the Northern Hemisphere summer (67% chance in June-August 2021).

ENSO Status: What’s in store? History shows: • Only 8% of La Niñas have been followed by an El Niño. • Some numerical ocean-atmosphere models are suggesting another La Niña in late 2021 while others suggest ENSO neutral. • Odds slightly favor ENSO neutral.

June 2021 Outlook Temperature Outlook Rainfall Outlook Characterization: Warmer and drier than normal is anticipated for June of 2021 over the Northwest Geographic Area

July-Aug-Sep 2021 Outlook Temperature Outlook Rainfall Outlook Characterization: The entire contiguous US and Alaska are likely to experience a warmer-than-normal summer in 2021. Drier-than-usual weather is expected to be predominant over the Pacific Northwest.

June Large Fire Outlook Risk of large, costly fires requiring mobilization of extra resources is expected to remain above typical during June in central Oregon and central Washington and spready into southwest Oregon. July Large Fire Outlook Fire danger will worsen and elevated large fire risk will expand during July to include more of western Oregon and Washington. Eastern Washington will also be added due to lightning fire risk.

August Large Fire Outlook Elevated fire danger will continue over most of the region. Lightning fires will likely be the main risk. Septempber Large Fire Outlook High fire danger will continue although wind drive humancaused fires will be as much of a risk as lightning fires as lightning tends to diminish rapidly after mid-September.

Next Outlook: Around July 1 st 2021