


Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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782 FXUS63 KFGF 200233 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 933 PM CDT Sat Apr 19 2025 .KEY MESSAGES... - Near critical fire weather is expected Sunday afternoon. && .UPDATE... Issued at 931 PM CDT Sat Apr 19 2025 Skies remain clear across the area and dew point depressions are very large. For this reason, fog remains very unlikely. As a result, impacts tonight will be difficult to come by from weather. UPDATE Issued at 635 PM CDT Sat Apr 19 2025 Temperatures remain fairly warm this afternoon with clear skies the whole way. No weather impacts should occur overnight tonight as dewpoints are very low across the region and source regions for moisture today are sparse. && .DISCUSSION... Issued at 337 PM CDT Sat Apr 19 2025 ...Synopsis... Mid/upper level pattern features shortwave ridging over the Northern Plains, while the broad longwave trough remains south and east. Deep dry air will be in place through Sunday, which will play a role in fire weather concerns during peak mixing Sunday afternoon. A progressive wave arrives late Monday through Tuesday, when there is a 30 to 60 percent chance for greater than 0.25" of rainfall (highest chances in the Devils Lake Basin Tuesday). Probabilities for greater than 0.5" are much lower (20-30% in the Devils Lake Basin) as ensembles favor locations west for more organized deformation based on 700MB clusters (good agreement). Beyond this we transition into a zonal pattern with a tendency for split flow around our region. This does allow for another progressive wave to pass just to our south and east Thursday into Friday, with the highest chances (20-30%) for greater than 0.25" south of I-94. Temperatures will tend to be above average over the next 7 days, though still within a standard deviation of model climatology. ...Near Critical Fire Weather Sunday... Deep mixing, almost to 700 MB, is advertised by guidance to be in place through the day Sunday, while surface trough deepens ahead of a stalling frontal zone to our west. High clouds increase later in the afternoon/evening, but should remain thin enough initially not to inhibit mixing over our area. Due to efficient mixing and very dry air aloft Tds are more likely to fall closer to the 10th percentile of guidance, and with temps in mid to upper 60s RH values should fall to the 20-28% range. Highest winds aloft will be as a southwest LLJ progresses through the region late tonight and Sunday morning with lowering of winds aloft as we approach peak mixing in the afternoon. Wind gusts 25 to 30 mph are likely (NBM probs greater than 60% for 30mph+) within the central and northern Red River valley, however based on the timing of mixing/winds aloft these higher gusts are most likely after sunrise through midday. The highest mixed layer winds based on soundings during the afternoon tend to fall in the 20-25 mph in the central/northern RRV (teens in the far south), which lowers confidence in Red Flag Conditions being achieved. However, conditions will be close and with dry finer fuels in place near critical fire weather conditions can be expected. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 931 PM CDT Sat Apr 19 2025 Skies are clear across the area and aviation impacts will remain limited to increasing winds tomorrow. Peak gusts after 12z will look to be between 20 and 30 knots but shouldn`t get much higher than that. Low level wind shear remains possible tonight as winds increase but confidence remains low in intensity. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Perroux DISCUSSION...DJR AVIATION...Perroux