The first full week of July will be starting off cool, with temperatures around 10° below average today and tomorrow (maximums), but the warmth of summer is expected by the end of the week. The transition to cool started yesterday in some parts the of region yesterday with many North Dakota Agricultural Weather Network (NDAWN) stations recording maximums in the 70s (an error in Mott on map).
Those cooler reading will be common today, in fact, some locations will probably record a maximum in the upper 60s, with temperatures on Tuesday not all that much higher. But once we get to Wednesday, warmer air will begin to return and maximums by the end of the week are expected to once again get into the 80s.
The transition from the warmth of late last week and even into Sunday in the southern Red River Valley to the coolness of the next two days was associated with a cold front that triggered some severe weather and also excessive rain for some portions of the NDAWN mesonet coverage area. It was the northern Red River Valley into northwestern Minnesota that recorded the heaviest rainfall over the weekend.
The Stephen, Minnesota NDAWN station recorded 3.27 inches of rain, with all of that occurring Saturday Night into Sunday afternoon. Other unofficial reports of around 5 inches were reported on social media.
Some of the rain came in the form of severe thunderstorms with hail and strong wind being the two severe parameters observed over the weekend. July 4, after recording maximums near 100° in northwestern North Dakota, severe weather quickly brought in cooler temperatures, with hail 3″ in diameter reported near Crosby, ND with strong wind reports near the Highway 2 and Missouri River Valley region.
On July 5, the main weather feature was excessive rain, but there were a few reports of high wind in northeastern North Dakota into northwestern Minnesota.
Maximums behind the front that moved through the region yesterday will be in the upper 60s to lower 70s today.
Maximums on Tuesday will be a bit warmer, but by only 3° to 6° it appears, meaning, mainly 70s on Tuesday. It will be Wednesday that a transition to warmer temperatures will begin in earnest.
The transition to warmer temperatures will come courtesy of a shift of the upper-level wind flow from a northwesterly direction today and tomorrow, to a more zonal flow later in the week, therefore, not only will that bring a warmer temperature regime to the region toward the end of the week, but it should also shift the smoke from the fires in Saskatchewan from flowing toward the United States to staying in southern Canada and blowing toward Ontario.
The transition to warmer temperatures may trigger some thunderstorm or shower activity mid-week, but overall, the week looks dry with a warming trend. At this time the main threat of rainfall looks to be this upcoming weekend of July 11-12.
Daryl Ritchison