Alaska summer outlook leans warmer, but not as a simple El Niño story

Alaska is heading into summer with federal forecasters favoring warmer-than-normal temperatures for much of the state, but the official outlook is not a simple El Niño story.

El Niño is likely to emerge soon, with an 82% chance during May, June and July, according to the National Weather Service Climate Prediction Center. But peak strength remains uncertain, and stronger El Niño events do not guarantee stronger impacts in Alaska.

Federal forecasters favor above-normal temperatures for most of Alaska from June through August. Only the North Slope falls outside that tilt. Even coastal Southwest Alaska and the Alaska Peninsula, where cooler sea-surface temperatures often hold down early-season heat, are given elevated odds of above-normal temperatures over the full three-month period.

That does not mean constant heat. Seasonal outlooks are probability forecasts. A warmer-than-normal summer can still include cool weeks, storms and sharp regional differences.

Western and northern mainland Alaska are favored to see above-normal precipitation this summer. Southern Alaska is less certain. El Niño summers tend to be drier in southern Alaska, but the official June-August outlook leaves southern Alaska in the equal chances category, meaning forecasters do not have a strong enough signal to favor wet, dry or near-normal precipitation.

Drought and wildfire

Alaska has only small patches of abnormal dryness, and drought development is not forecast by the end of summer, according to NOAA's Seasonal Drought Outlook. That does not mean every community will get regular rain. It means federal forecasters do not currently see the ingredients for a broad Alaska drought through August.

Wildfire risk is not being forecast as unusually severe statewide. Alaska Predictive Services and national fire outlooks call for normal fire potential in Alaska. Normal Alaska fire season still includes dangerous periods when deep fuels dry out, lightning starts fires, humidity drops or wind pushes an existing fire.

Heat advisories

The National Weather Service office in Anchorage will begin issuing Heat Advisories in its forecast area on or about June 9. The advisories will replace Special Weather Statements for heat-related hazards.

The Anchorage office set advisory thresholds as low as 70 degrees in some coastal, island and Southwest Alaska zones, 75 degrees in others, and 80 degrees in parts of Southcentral and Southwest. The thresholds must be met for two or more days.

That does not mean a heat wave is forecast for June 9. It means forecasters are adding a clearer public-warning system for Alaska heat, where many homes, schools and public buildings are not built around air conditioning.