Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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611 FXUS63 KFGF 181125 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 625 AM CDT Tue Jun 18 2024 .KEY MESSAGES... - Scattered severe thunderstorm chances continue this morning along a line of storms and heavy rain. Impacts from severe storms will diminish after around 8am. - Flash flooding remains possible today as a line of storms and moderate rainfall moves slowly eastward across the area. - Additional chances for thunderstorms and heavy rain are possible late Thursday through early Saturday. && .DISCUSSION... Issued at 350 AM CDT Tue Jun 18 2024 ...Synopsis... Southwest flow continues across the Northern Plains and Upper Midwest, with deep H5 troughing across the Pacific Northwest and strong H5 ridging over the Eastern CONUS. Ensemble guidance is somewhat consistent in weakening the eastern ridge very slowly over the course of the next week or so; however, the timing of this weakening will strongly determine what impacts we can expect as we head into the weekend. There is a continued signal for heavy rain and perhaps a few strong thunderstorms across a good portion of southeastern North Dakota and west-central Minnesota as another shortwave develops later this week. ...Scattered Severe Thunderstorms This Morning... Severe thunderstorm chances will diminish from west to east this morning, with most of the risk pushing east of the forecast area by around 8am. Primary impacts will be in the southern Red River Valley and west-central/northwest Minnesota, and will include thunderstorm wind gusts as high as 60 mph. ...Moderate Rain Diminishes Slowly Today... Periods of moderate rainfall have been following a line of storms through much of the morning. For the Red River Valley westward, most shower activity is expected to end by around midday; however, points east could see moderate rain persist into the middle to late afternoon hours before pushing off to the east. ...Active Pattern Continues Thursday through Saturday... After a period of relatively quiet weather Wednesday and early Thursday, another system is expected to bring additional rain and thunderstorm chances to the area late this week and into the weekend. The position of the H5 ridge will ultimately determine how much moisture will be able to work into the Northern Plains, with most ensemble members showing the potential for mixing ratios exceeding 12 g/Kg. If the ridge weakens, we would see lower potential moisture; however, clusters slightly favor a stronger ridge, which would allow a more direct moisture fetch out of east Texas. Current probabilities are highest across southeastern North Dakota and west-central Minnesota, where there is an 80 percent chance to see 0.50 inch or more rain late Thursday through early Saturday. Thunderstorm potential exists; however, there is a large degree of variability in model sounding output at this time. Most guidance allows for at least a mention of a few elevated storms capable of reaching minimal severe limits. && .AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/... Issued at 625 AM CDT Tue Jun 18 2024 Light rain continues across the area this morning with -RA observed at all TAF sites. Look for rain to become more scattered as the day progresses, with a reduction in ceilings heading into the mid morning hours. Conditions slowly improve heading into the mid to late afternoon; however, some guidance suggests another round of showers and storms could develop mainly east of the Red River Valley, potentially impacting KBJI later in the afternoon. Confidence in this solution is rather low at this time. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...Flood Watch through Wednesday morning for NDZ027-029-030-038- 039-049-052-053. MN...Flood Watch through Wednesday morning for MNZ001>003-005-006- 008-009-013>017-022>024-027>032-040. && $$ DISCUSSION...Lynch AVIATION...Lynch