April brings frost, sleepless nights for growers

While many Washingtonians hoped the unusually warm April Fools’ Day weather was a harbinger of things to come, Mother Nature had other plans.

Despite temperatures in the 70s on April 1, the transition from March didn’t mean the end of frost worries in Washington. The strengthening sun was no match for cold air masses that descended in April, leaving growers to suffer through numerous sleepless nights. From April 8 to 24, Moxee, Wash. experienced sub-freezing temperatures for 15 days. However, as often the case, location determined the severity of the frost conditions during April. In contrast to 18 sub-freezing mornings in Moxee during April, Royal City East failed to even reach 32 degrees.

“Unfortunately, there have been reports of cold damage across several agricultural regions of Washington during April,” said AgWeatherNet Director Gerrit Hoogenboom. “Despite our consistent efforts to disseminate vital weather information to growers, these events serve as sobering reminders of the need to remain vigilant during critical periods.”

Overall, however, central Washington temperatures were slightly above normal during April.

“Despite several frosty mornings, April temperatures were not unusually cold,” said AgWeatherNet meteorologist Nic Loyd. “Temperatures climbed into the 70s on April 1 and 2, and again from the 24 to the 26. Overall, monthly temperatures at Prosser were about one-half degree above average.”

Following warmth in the beginning of the month, wet conditions from April 4 to 7 yielded nearly 3 inches of rain at Long Beach. Although the low temperature at Moxee was a mild 51 degrees on April 5, cooler air quickly followed. The rain-cooled high temperature at Omak was only 47 degrees on April 7, while lows on April 8 were in the upper 20s to around 30 degrees in colder spots. After the passage of a windy and mild storm on April 10, a potent storm system on April 12 and 13 spawned rainfall, mountain snow, and winds up to 66 mph at Wenatchee Heights. Cooler air in the storm’s wake promoted the unsettled and frosty weather that dominated the mid-month time period. Highs were only in the 40s and 50s in most areas, while minimum temperatures dropped to as low as 19 degrees at LaCrosse on April 17.

On April 24, Ritzville dropped to 25 degrees, as frost continued to keep an icy hold on the region. A strong ridge of high pressure sent temperatures soaring into the 70s and 80s from April 24 to 26 during the warmest weather of 2013. Vancouver reached 77 degrees on April 26, while the 86-degree high at Desert Aire was the warmest temperature recorded by AgWeatherNet since September 2012.

Alas, a strong storm on April 29 delivered additional rain and mountain snow to the state, as winds gusted over 50 mph. Cold morning temperatures in the 20s and 30s returned on April 30, as the high struggled to reach the 50s and 60s.