NDCMP Weather Forecast

	District 1					District 2
Transition (UTC)		21		6			0		0
	First		Second		Third	First		Second		Third
Forecasted Weather	NO SIG		TSRA		TSRA

Forecaster: Parker Alvstad

Synopsis

The chance for showers and thunderstorms gradually increases starting late this afternoon before peaking tomorrow afternoon. These storms should only reach TSRA status.

Currently, southwest North Dakota is between an upper level low over Manitoba and a ridge to the west. Both will move east throughout the forecast period, making flow zonal to northwesterly through tomorrow morning. The axis of the ridge will pass over around 9z which will slowly change flow to southwesterly in association with an upper level low that moves onshore over British Columbia and winds up in eastern Washington by briefing tomorrow. A shortwave will move through the region after 9z, though the best forcing will be north. 700mb flow is more zonal today, and some enhanced vorticity over the district and south exists this afternoon and evening.

Below, low pressure in Manitoba moves northeast and a new area of low pressure develops in Wyoming this evening. This will lift north into Montana overnight before winding up in northwest North Dakota by tomorrow's briefing. A secondary area of low pressure may be evident in South Dakota tomorrow morning as well. Westerly winds today push moisture out before the developing low advects moisture back in overnight. This will bring dewpoints from low to mid 50s to upper 60s by tomorrow morning. Though there is some instability today with slight capping (750 J/kg with -30 CIN), the best instability is south and west. Overnight this moves into the district, and by tomorrow's briefing the combination of temperatures and moisture will lead to potentially extreme instability over the region (4000+ J/kg).

Though there is upper level ridging, subtle 700mb shortwaves to the south will likely trigger some isolated storms late this afternoon. This won't have influence close to the district until 21z which makes the forecast NO SIG beforehand. After 21z, CAMs are all over the place (as usual). The most likely region of storms is close to the Black Hills, however a couple have storms over eastern Bowman County this evening. This is dependent on where the best buoyancy is. Though the best conditions are south, there is a high enough chance for storms to be close enough to the district for TSRA to be forecasted this evening (though the chance for TSRA is low). This initial chance for storms will be over by 3z.

CAMs come back into agreement after 6z when the first shortwave behind the ridge moves in. Though the best shortwave energy is north, increased buoyancy and a bit of an LLJ makes storm development favorable after 9z across the region. If temperatures don?t cool as much as expected, a weaker cap present over the district could spark some TSRA. Capping will only decrease around the time of briefing which increases the chance for storms.

With extreme buoyancy and adequate forcing, strong to severe storms are likely over and northeast of the district throughout tomorrow and Friday.