The May 5 through May 11, 2016 Weather Outlook
The next 7 days will transition from temperatures being well above average to temperatures ending up near or perhaps even below average depending on the track of an area of low pressure next week across the north central part of the United States.
In the short term, it will be quite warm for early May with temperatures perhaps approaching 90° in some locations today (Thursday) as a large ridge of high pressure aloft moves across North Dakota (Figure 1). If you look closely, the upper-level wind flow (parallel to the black lines) is shaped like the Greek letter omega (Ω). This tends to be a warm and dry pattern in the northern plains, but this pattern will quickly break down in the next 48 hours and with it a trend toward cooler and wetter weather.
A cold front will move across North Dakota on Friday, with it, some spotty showers and thunderstorms that likely will drop minimal moisture in the locations that do record any rain. The weekend should be noticeably cooler with a storm moving out of the Rocky Mountains on Sunday and dropping some rain that day in South Dakota. That rain is projected to lift into North Dakota Monday and Tuesday of next week. The usual uncertainty exists as to how much moisture will fall across the region and where, but certainly some planting delays can be anticipated. Until then, besides the slight risk of a few showers/thunderstorms on Friday, the weather looks dry and “plant 16” should be able to continue unabated through the weekend. Beyond the next 7 days, the current pattern would suggestion a period of below average temperatures mid-month.
The projected Growing Degree Days (GDDs), base 50°, 44° and 34° for the period May 5 through May 11, 2016 are presented in Figure 2. In later editions of this publication, forecasts for relative humidity hours above 85% will be given.
Daryl Ritchison, Meteorologist
Forecast Blog: ndsu.edu/ndawnblog