Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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277 FXUS63 KFGF 290001 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 701 PM CDT Sun Apr 28 2024 .KEY MESSAGES... - 30 percent chance for an inch or greater of snow in north central Minnesota Monday morning bringing the chance for isolated minor impacts to travel. - Multiple systems will continue to bring periods of rain to the region from Tuesday through the end of the week. && .UPDATE... Issued at 701 PM CDT Sun Apr 28 2024 The band of precipitation currently sits in between Fargo and Grand Forks. This band is still expected to continue to move northward throughout the night. Total rainfall seen from this band has been up to half an inch. As we lose sunlight, lighter amounts of rain up to a couple tenths is more likely for counties north of Highway 200. Forecast remains on track. && .DISCUSSION... Issued at 228 PM CDT Sun Apr 28 2024 Upper level low pressure system is centered over the central plains tracking northeast into Minnesota and Iowa. Rain (moderate at times) is situated along and north of the upper level low and is tracking northward. This rain will continue to overspread eastern North Dakota and northwestern Minnesota throughout the remainder of the afternoon and into the evening hours. The low pressure system is associated with the southwesterly flow aloft that will be stuck in place through mid week before turning zonal/northwesterly end of the week as represented by cluster analysis. As the precipitation moves northward this evening and overnight snow may mix in at times in eastern North Dakota and northwestern Minnesota as temperatures near the surface cool to the low to mid 30s. Areas near Lake of the Woods and Beltrami (north central Minnesota) reach the low 30s easily overnight bringing the chance (30%) for rain to transition over to snow. Atmospheric soundings differ in residence time, onset of snow, and growth within the DGZ. 30% of guidance has snow lasting longer, becoming moderate at times, and longer time within the DGZ. This leads to accumulations of an 1 or more in north central Minnesota on elevated surfaces. There exists a chance (30%) for isolated impacts to travel where snow starts to accumulate on elevated surface. However, majority (70%) of guidance has the rain/snow mix remaining, as saturation is through the low and mid levels, temperatures hover above freezing/are isothermal in the low levels, and DGZ growth is limited. This would bring little to no impacts and up to an inch of new snowfall. Likely (70%) QPF of 0.50 to 1.25 inches from this evening through Monday evening. Temperatures quickly rewarm by Monday mid morning transitioning all rain/snow back over to rain, with the system exiting by the evening hours. Temperatures warm into the mid to upper 40s for Monday afternoon. Dry conditions move in briefly Monday night, with temperatures in the low to mid 30s. An active pattern will continue beyond Monday, as a trough and associated jet streak over the western US passes several waves through the Northern Plains. The first shortwave arrives Tuesday. A generally north to south oriented band of rain driven by weak frontogenesis will propagate from west to east. Rainfall will last longest across the north, as the trough becomes negatively tilted, allowing rain showers to pivot along the International border. Along the southern edge of the band in southeastern North Dakota and west central Minnesota, small CAPE values foster the potential to see thunder and locally heavier rainfall. A slight north or south shift in the track of the low would correspondingly shift the heavier axis of rainfall and the amount of instability to the south that is able to work northward. Probabilities for at least a half inch of rain are 50% north of Highway 2 during this period. Probabilities are 20% in southeastern North Dakota. The main trough will propagate east over the Rockies late in the week. In turn, a larger wave will pass through the Northern Plains. Cluster analysis clearly shows significant disagreements in the track, timing and strength of this wave. At this time, it can be deduced that while another system capable of bringing rain to the region will be in the area, specifics are uncertain. What is more consistent is that temperatures will be persistently near or below average through next weekend, with highs generally in the 50s and lows in the 30s. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 630 PM CDT Sun Apr 28 2024 Light rain continues to lift northward, with KFAR likely seeing more showers than steady rain through much of the evening. Light rain is currently being observed at KBJI, and will move into KGFK and KTVF by around 03Z. A transition to a mix of rain and snow remains possible heading into Monday morning, with little to no impact expected from accumulating snow. Any snow will transition back to rain by mid-morning. As for ceilings, a best case scenario of MVFR is expected this evening, with the expectation of more widespread IFR CIGs later tonight and into Monday morning. Some guidance suggests LIFR CIGs are possible around sunrise Monday; however, there is low confidence regarding location, and consistency is minimal. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...MM DISCUSSION...Rafferty/Spender AVIATION...Lynch