Jamestown surpasses average monthly precipitation totals for May
May 17—JAMESTOWN — Jamestown has already surpassed the average monthly precipitation totals for May.
Jamestown has received almost 4 inches of rain this month as of Tuesday, May 16, according to precipitation measurements taken at the North Dakota State Hospital. The average monthly precipitation for May is 3.26 inches, said Jason Anglin, a meteorologist with the National Weather Service in Bismarck.
He said an active pattern created a Colorado low that brought rain to the area. Jamestown received more than an inch of rain on Friday into Saturday morning, May 12-13, according to measurements at 6 a.m. Saturday at the North Dakota State Hospital.
Stutsman County is currently extremely wet, according to the U.S. Drought Monitor map. The current conditions are wetter than 95% to 98% of past conditions.
After the additional rainfall over the weekend, combined releases from Jamestown and Pipestem reservoirs will increase to 1,600 cubic feet per second by Wednesday, May 17, said Alex Flanigan, water manager of Pipestem Dam for the U.S. Army Corps of Engineers.
Releases from Jamestown Reservoir increased from 900 cfs to 1,000 cfs on Tuesday and were expected to increase by another 100 cfs again on Wednesday to 1,100 cfs.
The water elevation at Jamestown Reservoir was at 1,443.5 feet above mean sea level as of Tuesday morning, according to Bob Martin, part-time assistant Pipestem Dam manager for the Corps of Engineers. He said the water will start flowing into the emergency spillway at Jamestown Reservoir once the elevation reaches 1,454 feet AMSL.
Releases from Pipestem Reservoir were increased from 400 cfs to 500 cfs on Monday. Martin said the water elevation at Pipestem Reservoir was at 1,474 feet AMSL as of Tuesday and can go as high as 1,492 feet AMSL before it reaches the top of the spillway.
He said the inflows coming into Pipestem Creek in Pingree is 1,100 cfs. The inflows coming into the James River is at 1,200 cfs from Arrowwood National Wildlife Refuge, he said.
Anglin said the state saw a La Nina weather pattern for the last three years. He said the forecast includes a transition to an El Nino climate pattern this fall.
Allen Schlag, a hydrologist for the NWS in Bismarck, previously said the El Nino climate pattern historically produces a daily warm and dry pattern for much of the U.S.
During El Nino, warm water pushes toward the West Coast of the U.S., causing the Pacific jet stream to move south of its neutral position, according to the National Oceanic and Atmospheric Administration. The NOAA says the shift causes areas in the northern U.S. and Canada to be drier and warmer than usual.
During La Nina, warm water gets pushed toward Asia, causing cold waters in the Pacific Ocean to push the jet stream northward, according to the NOAA. The northern U.S. and Canada tend to be wetter and colder during La Nina winters, NOAA says.
"Typically in the La Nina for the winter as it gets a little cooler, (there's) a chance for a little bit of above-normal precipitation versus in the El Nino pattern it can typically be a little bit of a warmer winter with maybe a slight chance of below-normal precipitation," Anglin said.
Anglin said a cold front was expected to move through Tuesday evening into Wednesday that could bring a chance of rain and thunderstorms.
"Then it kind of cools off before we warm back up," he said. "There's really not a lot of chances for precipitation during this warm-up into next week, maybe until probably mid next week for the next chance of more showers and thunderstorms."
He said high temperatures are expected to be in the 60s on Thursday and Friday before reaching the 70s over the weekend.
