Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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407 FXUS63 KFGF 170332 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1032 PM CDT Thu May 16 2024 .KEY MESSAGES... - Isolated to scattered showers and thunderstorms possible through tonight. An isolated stronger storm possible this evening, mainly in eastern North Dakota. - Impacts possible Friday. Isolated strong to severe thunderstorms are possible Friday afternoon and evening. Damaging wind gusts and hail up to 1 inch in diameter are the main concern. - Gusty westerly winds possible on Saturday, with gusts up to 45 mph. && .UPDATE... Issued at 1032 PM CDT Thu May 16 2024 Main supercell that affected Griggs, Steele, and Barnes counties is slowly weakening as it moves southeast into Cass county. We did get hail reports out of the Luverne, ND and Pillsbury, ND area over the past 2 hours of quarter size hail covering the ground. Air is starting to stabilize across southeastern ND allowing for the supercell to diminish in intensity overtime. A band of precipitation is moving through Barnes, Griggs, and Ransom counties this hour bringing lightning and wind gusts up to 35mph as the outflow boundary extends just east of the main line. Radar indicates the outflow extending as far north as Nelson county and as far south as Sargent. This outflow will propagate eastward over the next several hours bringing the chance for 35mph winds gusts. UPDATE Issued at 629 PM CDT Thu May 16 2024 We are currently watching the thunderstorms around the Devils Lake Basin and also in southern Manitoba. These storms have produced frequent lightning over the past hour. The one storm in Eddy county bears watching as we see lightning jumps with quick updrafts. Further storms are toward the west in central ND that will track eastward as we head through the evening hours and into the overnight period. Any isolated storms ahead of the wave of precipitation in central ND has the potential for small hail or brief gusty winds. && .DISCUSSION... Issued at 340 PM CDT Thu May 16 2024 Surface low in northern Minnesota continues to slowly push eastward late this afternoon. As a result, low to mid level clouds continue to linger for these areas and will gradually lift through the evening. Meanwhile, clearing skies are being found across eastern North Dakota although will gradually fill in with cloud cover this evening as a surface trough moves into the area. Along with surface trough could be the focus for more showers and thunderstorms later this afternoon through this evening. If these storms through this evening become surface based, there is modest CAPE over 1000 J/KG t to fuel them. Mix layer CAPE is not quite as high though. 0 to 6 KM shear of around 30 to 40 knots is also adequate for stronger storms. Looking at soundings, the CAPE appears skinny despite some turn in the hodographs. Overall an isolated stronger storm is possible this evening with some small hail and gusty winds possible. These thunderstorms then look to merge into a line a weak showers moving from west to east through the night. Some patchy fog is possible tonight before these showers arrive in eastern portions of the CWA, mainly from Lake of the Woods to the Red Lake area. With the cloud cover lows tonight will generally be in the mid 40s to mid 50s. Showers then exit eastern areas of the CWA Friday morning. As a surface low moves across southern Canada a warm front will lift across the CWA. This will bring a southerly breeze and warming temperatures in the upper 70s to mid 80s. Most of the day looks dry Friday, although increased instability along the warm front will bring about some slight chances for an isolated thunderstorms, dependent on if the CAP can be overcome. Friday evening through the night, a cold front will push from west to east across the CWA. This will have ample instability and shear to work with in central ND. By the time it reaches eastern ND and NW MN, thunderstorms could already be formed into a line of thunderstorms. There will still be an adequate amount of cape and shear when this line moves through. DCAPE values of 1000 J/KG and 0 to 3 km shear of over 20 knots indicate strong winds being the main threat. If an isolated storm can get going ahead of this line, hail up to an inch in diameter is possible. Lows Friday night will remain mild in the 50s. This weekend, then looks to be cooler yet still mild. Strong winds behind the mentioned cold front could be found on Saturday, especially in eastern North Dakota where near advisory level winds are possible. A developing low lee of the northern Rockies could return chances for showers and thunderstorms on Sunday afternoon through Sunday night. Depending on timing of this low perhaps a strong storm is possible Sunday afternoon and evening. Clusters then indicate a broad trough pattern going into next week. Even though there are still decent spreads in the NBM and clusters, this will likely be a cooler pattern with periodic chances for showers and thunderstorms. && .AVIATION /00Z TAFS THROUGH 00Z SATURDAY/... Issued at 1032 PM CDT Thu May 16 2024 A band of broken precipitation is moving through Griggs, Barnes, and Ransom counties towards the east affecting FAR within the 6z-10z timeframe. Some embedded lightning and thunder will be possible at times. There is also an outflow boundary that extends from Nelson through Sargent county that may bring isolated gusts up to 30kts as it passes through the Red River Valley over the next several hours. Isolated chances for showers for GFK, TVF, and DVL overnight. Conditions dry out after this main band moves east around sunrise. FEW to SCT clouds post 15z for all sites, with a BKN cloud deck and precipitation chances increasing from west to east 21-23z. -TSRA near the end of the TAF period for all sites as another round of precipitation moves in. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Spender DISCUSSION...Godon AVIATION...Spender