NDCMP Weather Forecast

	District 1					District 2
Transition (UTC)		3		9			3		12
	First		Second		Third	First		Second		Third
Forecasted Weather	NO SIG		RAIN		NO SIG	NO SIG		RAIN		RAIN

Forecaster: Daniel Brothers

Synopsis

An upper level low moves towards and starts impacting ND today. An occluded front out ahead of the upper level low is entering W ND at briefing. The lower atmosphere starts drying out noticeably behind the front, resulting in more stable air and little chance for any thunderstorms. The atmosphere ahead of the front is capped, and it takes until close to 00Z before the models have the cap breaking. Unfortunately, the front is in Central ND and E of the districts by the time the cap breaks. Behind the front, synoptic forcing with the upper level low could still force showers tonight and into tomorrow for W ND, especially the NW. Expect no significant weather for at least Thursday and Friday after this system is past.

For D1, the front is passing currently, and is comfortably E of the district before the cap breaks. In the drier air over the district this afternoon and evening no convection is expected. However, as the stronger synoptic forcing with the upper level low moves into the area some rain showers could occur, likely between 03Z and 09Z. By morning, any rain should be out of district and the next couple days look dry.

For D2, the front is currently crossing into ND. The cap should hold until close to 00Z, by which point it should be E of the district. But D2 extends farther E than D1, so if the cap breaks earlier than expected, you might see a thunderstorm near the E edge of Mountrail County. You can see this reflected in the SPC Outlook, which does have E Mountrail in the marginal risk. More likely, and what I'm forecasting, is that storms fire on or just E of Minot. Like D1, rain showers are possible as the upper level low starts to move over ND after sunset. D2 is closer to the passage of that low, so rain showers can hold on longer into tomorrow morning and may even be a factor for tomorrow's forecast, though none are expected to be operationally significant. After the passage of the low the rest of the work week looks dry.

8/28/24

Flash Flood Guidance (Click Image for 1hr, 3hr, & 6hr Graphics)

The upper level low moves across ND starting today and lingering through tomorrow

1523Z Surface obs showing the wind shift associated with the front just west of ND

1520Z Visible Satellite. Note the low overcast area in E MT which lines up well with the location of the front

18Z Surface temps and winds show the front just crossing the ND border at 18Z

18Z Surface Dew Points also do a good job of showing the location of the front

18Z Surface fronts from WPC show the occluded front a little further through than the models at the same time

21Z Surface CAPE shows instability east of D1 and just a little in E D2, but capped

20Z NAM Nest reflectivity shows perhaps some light showers (but more likely just clouds) moving through W ND before the cap breaks

00Z Surface shows the front E of both districts at 00Z, about the time the modles show the cap breaking

The best moisture along the front is also E of the districts at 00Z, but there is ok moisture lingering in D2

MUCAPE at 00Z is (mostly) E of the districts

00Z NAM Nest reflectivity showing the location of convection when it has the cap break

00Z HRRR reflectivity pretty much agrees with the Nest

There is, as you would expect, plenty of positive vorticity associated with the upper level low, but no instability to work with behind the front

06Z NAM Nest reflectivity shows that some rain does develop with the vorticity off the low, but it remains showers rather than thunderstorms

Again, the HRRR largely agrees with the Nest, with some showers overnight

12Z NAM Nest keeps some showery activity in D2 tomorrow morning

The HRRR largely agrees in the morning, as well

Indices

	Lifted Index (<1)	K index (>30)	Total Totals (>48)	Sweat (>200)	Cape (>125)	CIN (>-100)	Bulk Richarson Number (>3)	Helicity (>125)
D1	9.2	14.8	37.8	124	0	0	0	-15
ISN	8.7	10.9	42.1	125	0	0	0	-129
MOT	-1.3	35.3	47.7	235	622	-54	15	112

	Jefferson Index (>28.5)	Cross Totals (>18.65)	Thompson Index (>28.5)	S Index (>35.8)	Showalter Index (<=0.5)	Cap Strength (0-2.65°C)
D1	20	13.7	5.6	22.8	7.2	0
ISN	19	17.6	2.2	21.8	5.2	0
MOT	32	23	36.6	42.2	-1.4	1

Weather Features

Cyclonic Vorticity Advection
Occluded Front
Upper Level Low

Soundings

Bowman Sounding Text

Williston Sounding Text

Minot Sounding Text