Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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705 FXUS63 KFGF 151742 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1242 PM CDT Sat Jun 15 2024 .KEY MESSAGES... - Isolated to scattered severe thunderstorms are possible today for the Devils Lake area and portions of the northern Red River Valley. Impacts could include damaging wind gusts up to 60 mph and large hail up to the size of quarters. - Isolated severe thunderstorms are possible Sunday afternoon in the southern Red River Valley and west-central Minnesota. Impacts are possible and could include strong wind gusts and large hail up to the size of quarters. - There will be another chance for scattered severe thunderstorms on Monday, with much of the area seeing the potential for large hail and damaging wind gusts. Flash flooding is possible as there is support for persistent heavy rainfall. && .UPDATE... Issued at 1242 PM CDT Sat Jun 15 2024 Adjusted cloud cover and POPs a bit for current radar and satellite trends. Temps still seem on track to top out mostly in the 70s, with a few spotty 80s where there is more sunshine in the western counties. UPDATE Issued at 1001 AM CDT Sat Jun 15 2024 Showers starting to exit our northeastern counties out through the Lake of the Woods area, so lowered POPs a bit. Still could see our southeastern counties get clipped from showers moving through with a shortwave traveling through MN. However, impacts at this point look minimal with light rain. Otherwise fairly quiet with most of our severe thunderstorm potential holding off until later tonight. Issued at 745 AM CDT Sat Jun 15 2024 Showers and mainly embedded thunderstorms continue to move slowly off to the east this morning, with southerly to southeasterly winds increasing. Temperatures are hovering in the low to mid 60s with dew points in the upper 50s to low 60s. Minimal adjustments were needed this update as the forecast remains on track. && .DISCUSSION... Issued at 411 AM CDT Sat Jun 15 2024 ...Synopsis... A very active weather pattern continues across the Northern Plains and into the Upper Midwest through the next several days. Upper ridging builds into the Ohio Valley and the Eastern Seaboard starting today, which will continue into the early part of next week. As this happens, H5 troughing digs into the western Conus, facilitating a favorable pattern for repeated trough passages along southwesterly flow into the Northern Plains. Moisture will be able to flow into the area along strong 850 mb transport winds, with long fetch gulf moisture working into the northern Mississippi Valley ahead of our H5 troughs. This will set the stage for active weather to include strong to severe thunderstorms and very heavy rainfall. ...Isolated to Scattered Severe Thunderstorms Today and Sunday... Theta-e values continue to climb this morning as mixing ratios are now in the range of 11-13 g/Kg in central North Dakota. This moisture will continue working eastward into the Devils Lake Basin by early afternoon, with SBCAPE climbing upwards of 1500 J/Kg by late afternoon. Shear in the 0-3Km and 0-6Km layers remain supportive of discrete cells; however, forcing is expected to stay west of the area, with remnant strong to severe storms working into the Devils Lake Basin later in the afternoon and into the evening hours. Environmental support for discrete cells diminishes as this happens, with clusters and possibly line segments being the primary mode heading into late evening. Soundings support large hail up to 1 inch, with a more conditional threat of damaging wind gusts due to storms becoming elevated during the overnight period. For Sunday, the theta-e gradient along a lifting warm front will be our primary driver of potentially strong to severe storms. While shear in the low levels supports a mention of tornadoes, the better environment looks to stay south of the area. CAPE still looks supportive of large hail and damaging wind gusts, however, primarily for portions of the southern Red River Valley and west-central Minnesota. ...Scattered Severe Thunderstorms Monday... A stronger trough is set to bring severe thunderstorm chances back into area on Monday as moisture continues to stream into the area. Mixing ratios climb upwards of 14 g/Kg in the southern Red River Valley with values of up to 12 g/Kg for the central and northern Red River Valley. This will usher in a conditional threat of severe storms that could expand across a larger portion of the area. How much coverage we see will depend on the speed of the theta-e gradient boundary associated with a push of cooler and drier air working in from the northwest. Guidance shows a range of solutions that support anything from elevated large hail producing supercells, to potentially tornadic cells ahead of the boundary. With the slow forward movement expected with this system, we could also see a flash flood risk emerge as training storms could move repeatedly over the same area. The best chances for impacts, resides in the southern and central Red River Valley and portions of west central Minnesota; however, the position of the boundary will ultimately determine the axis of heaviest precipitation and strongest thunderstorm potential. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1242 PM CDT Sat Jun 15 2024 VFR conditions, but some MVFR and then IFR as a trough of low pressure comes into the Red River Valley tonight, starting in the more western TAF sites this evening and spreading eastward as the night goes on. Improvement by the end of the period in a similar west to east direction by mid-day tomorrow. Some weakening convection coming through, but uncertain how much will make it to our airports, so just have VCSH at KDVL for now. Winds will shift from a southerly direction with gusts around 25 kts this afternoon. Decreasing a bit to around 10 kts and going to a southeast and then southwest and finally west to northwest as the trough axis moves through by tomorrow morning. Winds will pick up the the end of the period with gusts to around 20 kts again. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Lynch/JR DISCUSSION...Lynch AVIATION...JR