It’s certainly been another month of weather extremes across the country. Massive storms have been moving from the Far West into the nation’s midsection bringing severe weather that includes tornado outbreaks, hail, heavy rainfall and widespread flooding.
Here in the Inland Northwest, we had the driest first two weeks of May in recorded history. Then, nearly 2 inches of rain fell from the 15th through the 18th. Cliff tells me that it rained for 61 straight hours at his station. With the additional moisture late last week, rainfall totals, as of late Saturday, at the Spokane International Airport are close to 1.20 inches. Spokane’s normal rainfall in May is 1.63 inches. In Coeur d’Alene, we’re already above the 2.37 average May rainfall as over 2.70 inches has fallen.
Our moisture season is doing pretty well for 2019, at least for now. Cliff has measured close to 15.25 inches, compared to a normal near 11.50 inches. Our normal for an entire season is 26.77 inches, so it looks like 2019 will finish above average once again.
There may be a few showers around the region late this week, otherwise we should have some nice and warm weather. More shower activity, and perhaps a thunderstorm or two, is expected early next week. As we move further into June, conditions are expected to turn drier than normal once again. For the upcoming summer season, Cliff and I do see another dry summer season, however it probably won’t be as rainless as the ones over the past two years based on the projected sea-surface temperature patterns.
As is often the case, July should be our driest month with wetter conditions expected later in August and September. Hopefully, this will shorten our fire season in Coeur d’Alene and across much of the Inland Northwest.
Speaking of sea-surface temperature patterns, the latest data shows that ocean waters along the West Coast of South America and along the Equatorial regions near the continent have cooled down to near-normal levels. However, there are still warmer than normal ocean temperatures to the west of that region, which indicates, according to the National Oceanic and Atmospheric Administration’s Climate Prediction Center, that we have a weak warmer than normal sea-surface temperature phenomenon, El Nino.
The Australian Bureau of Meteorology, the government organization in the Southern Hemisphere that closely watches the formations of El Ninos and La Ninas, say that we are in a “La Nada,” the in-between warmer El Nino and cooler La Nina. Officials at the Bureau state there is now only a 50 percent chance that an El Nino will be declared in the next few months.
As the region of warmer waters along the Equatorial regions continue to moderate, we would say that El Nino is not expected to last much longer. Some forecasts now say that this warm-water phenomenon may last until August.
NOAA still says there is about a 55 percent chance that this new warm water phenomenon will last into the summer 2019. Then, it’s quite likely that we’ll go back into a La Nada, the in-between warmer El Nino and the cooler La Nada sea-surface temperature event.
Since the late 1990s, we’ve seen El Ninos and La Ninas form very quickly. Therefore, it’s quite possible that we could be talking about the formation of a new cooler La Nina pattern toward the end of this year or in 2020. Remember, to get the big winter that Cliff has been forecasting, we need at least a moderate La Nina in the waters of the south-central Pacific Ocean.
Despite the recent weakening of El Nino, we’ve already felt the effects of that pattern. Across areas east of the Rockies, especially in the central and southern portions of the Great Plains, there have been eight tornado outbreaks since March 3. Since that date, there have been approximately 528 reported twisters in the U.S. The strongest was an EF4, in Beauregard, Ala., on March 3. The average number of tornadoes across the U.S. each year 1,253.
For a tornado to be classified as an EF4 on the Enhanced Fujita Scale, winds are estimated to be between 166 and 200 miles per hour resulting in “devastating damage.” For an EF5, the highest on the scale, winds are greater than 200 miles per hour and there is “incredible damage.”
In California, thanks to El Nino, moisture totals have been well above average in many places. At the Los Angeles International Airport, over a half-inch of rain fell this month taking their total to 16.77 inches since the beginning of their rainfall season on July 1, 2018. Their normal to date is close to 12.50 inches.
Northern California has seen a record amount of moisture for May. Sacramento up picked more than 3 inches of rain this month, compared to the normal of over a half-inch. For the 2018-19 rainy season, Sacramento has measured over 24 inches.