NDCMP Weather Forecast

Forecaster: Ben Schaefer

Synopsis

A fairly quiet weather day, with the exception of a chance for rain showers this evening and overnight, looks to be in store. The forecasted cold front moved through district earlier this morning and is now located to our south near the ND/SD border. This leaves the district in northwest flow, and will yield relatively cooler temperatures and lower surface moisture for today. Temperatures will top out in the upper-70s to low-80s across district this afternoon, with dew points, currently in the 50s, lowering into the mid to upper-40s.

The weak shortwave upper-level trough approaching the area that was mentioned in yesterday's forecast will continue to weaken and slide off to our southeast. This, along with better pre-frontal moisture and instability, will yield better chances for storms well to our southeast, in south-central and eastern North Dakota and southward. This weak shortwave trough is de-coupled from a stronger upper-level trough located to our north in Canada. This trough is expected to swoop southeast today, with an axis that will be centered just to our north near the Canadian border by sunset tonight. Associated with this trough, a secondary cold front will move into district from the northwest. This will bring our chances for rain this evening and overnight.

Given the now northwest top-to-bottom atmospheric flow across the region, there is no longer a warm air inversion right above the surface, and hence, hardly any capping this afternoon. However, this northwest flow, along with the drying out of our dewpoint values, will lead to little to no instability ahead of the cold front this evening. The CAM model solutions are in relative agreement about this lack of thermodynamic support. MUCAPE values may reach 500 J/kg locally in northeast MT, where mid-level lapse rates may be relatively higher. However, in district, the environment will likely be characterized by 0-200 J/kg of MUCAPE as the front passes through, with forecast soundings consistently showing saturation between roughly the 800-650mb level. This indicates the likelihood of stratiform rain. This rain will enter district from the northwest along the cold front sometime around 00Z this evening, and slowly make its way southeast, exiting the district shortly after midnight.

After the cold front and stratiform rain passage, temperatures will cool down quite a bit (highs around 70 degrees on Thursday), and a upper-level ridge/surface high pressure will begin to build in. This will likely bring back quiet weather to the region to end the week.

9/4/24

Indices

Weather Features

• Cold Front
• Jet Stream (PVA) RRQ or LFQ
• Short Wave Trough
• Smoke
• Speed Shear
• Surface High Pressure
• Upper Level Ridge
• Upper Level Trough

Soundings