Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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510 FXUS63 KFGF 110819 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 319 AM CDT Tue Jun 11 2024 .KEY MESSAGES... - Scattered thunderstorms Wednesday afternoon east of the Red River Valley with a marginal chance for severe storms. - More rain chances this weekend into next week with a 30% chance for more than 1" over a 3 day period. && .DISCUSSION... Issued at 319 AM CDT Tue Jun 11 2024 ...Synopsis... Showers currently moving east across northwest Minnesota this morning along a cold front with the attendant low northwest of Brandon Manitoba. As the low continues east amid westerly 500mb flow we begin to dry out with mid level ridging building in through the day. Steep near sfc lapse rates remain today, helping to maximize momentum transfer and create breezy conditions today as we remain well mixed. RH as low as the mid 30s with sustained winds in the low 20s gusting over 30mph in northeast North Dakota will create good burning conditions. Unlikely to approach near critical conditions with the limited RH potential but gusty winds may still create difficult conditions at times. ...Wednesday severe... Beyond today ridging continues to shift east with aid from another low amplitude trough and attendant cold front Wednesday afternoon. High based thunderstorms (~2000m) are expected to form along and ahead of this front. Primary forcing will be in northwest Minnesota in the afternoon with only a 70% chance for SBCAPE to exceed 1500 J/KG in our area. Bulk shear of 50+ kts (largely aided by strong 700-500mb flow) will support organized convection with wind up to 60 mph and hail to 1 inch, though early runs of higher res CAMs covering this period generally show the greatest threat to be to our south and east. A slower mid level trough could bring the threat further into our area but the trend has been for a more progressive wave over the past 24 hours. With the core of the ridge overhead Wednesday expect the warmest day of the year for most thus far across the region with highs widely reaching into the 80s with a few areas in the valley seeing enhanced mixing from downslope westerly winds off the escarpment possibly helping a few areas tap the 90 mark. At least it will be a dry heat with Tds in the 50s. Cooling off back into the 70s for the Thursday/Friday period with westerly flow aloft keeping us in a warm and dry continental airmass. ...Weekend rain chances... Surprisingly good agreement between global ensembles later in the week that long wave ridging will yield to a shortwave passing to our south amid southwest flow bringing warm air advection and deformation type rain to the upper midwest late week with a 40% chance for > 0.25". A second more potent pacific northwest trough then propagates east thorugh the weekend arriving in the Northern Plains/ Canadian Prairies early next week with better overall synoptic support through ensembles diverge by the weekend on timing and track limiting confidence past the initial late week wave. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1231 AM CDT Tue Jun 11 2024 Rain continues to move across eastern ND into northwest MN. Ceilings have remained VFR, but there are indications of MVFR starting to form in southern Canada. Latest guidance shows a weaker signal for sub-VFR conditions in ND with VFR now favored to prevail. NW MN there is still better potential for a period of MVFR as the rain transitions east and lower level moisture is shown to pool in the 09-14Z period (KTVF and KBJI impacted). Winds should increase 12-19kt range with increasing daytime gusts from the west (highest at KDVL) Tuesday. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ DISCUSSION...TT AVIATION...DJR