Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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768 FXUS63 KFGF 071736 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1236 PM CDT Sun Jul 7 2024 .KEY MESSAGES... - Scattered thunderstorms today into this evening. Main hazard is lightning along with brief very heavy rainfall rates. - Warming up late week with highs Friday-Saturday in the upper 80s to lower 90s. && .UPDATE... Issued at 1236 PM CDT Sun Jul 7 2024 As expected, a few more showers starting to develop in the southern Red River Valley as well as western MN as the lower levels destabilize. Adjusted POPs for current trends. UPDATE Issued at 948 AM CDT Sun Jul 7 2024 Tweaked POPs for current trends as showers continue to rotate around the upper low in central MN. Should still see some additional activity later this afternoon as we destabilize, but again not much shear to work with. Main threat still look to be lightning and brief heavy rain. && .DISCUSSION... Issued at 327 AM CDT Sun Jul 7 2024 ...Synopsis... 500 mb low at 08z near Fargo and it will be near Duluth by late this afternoon. This will continue the broad area of convection into this evening, most numerous coverage in the afternoon. Lingering weak 500 mb troughiness to continue Monday and Tuesday giving isolated afternoon thunderstorms. We will transition to a drier pattern mid to late week as 500 mb ridging that is building into Alberta moves east into the northern Plains. ...Today... Continued scattered convection near the 500 mb low and to the west as 500 mb temps though not as cool as Saturday still remain low enough so that MU CAPE in the 1500 j/kg are generated in North Dakota. Cloud cover and cooler temps at the sfc keep mean MU CAPE values closer to 1000 j/kg in northern Minnesota. Brief localized heavy rainfall rates and lightning are the main hazards. As we have seen cannot rule out a brief funnel cloud, small hail or wind gusts 30 mph or higher from any storm. NAM12 forecast of non supercell tornado parameter shows some risk of funnels in eastern ND west of the Red River valley this afternoon. Funnels did occur in an area west of the upper low in western ND Saturday so it would make sense that it will be possible west of the upper low in our area today. ...Late Week Heat... Continuing past Wednesday the western ridging finally progress far enough east to build low level thermal ridging over us and push sfc temps into the 80s. Building southerly 850mb flow Thursday into next weekend on the eastern periphery of this thermal ridge will promote increased mixing. This is reflected by the low spread in NBM maxT through the week with <7 degree spread between the 10th and 90th percentile any given day between now and Friday at a given point. Area highs climbing from the 70s and 80s today to upper 80s and even a few low 90s for some by the end of the week. HeatRisk (found at wpc.ncep.noaa.gov/heatrisk) is already showing a broad chunk of the area under a moderate risk of health related impacts for Friday and Saturday due to these warm temps. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 1236 PM CDT Sun Jul 7 2024 All sites VFR with some shower activity at the Red River and MN airports. Some strengthening of the convection will be possible in the next few hours, so kept VCTS mention at KFAR, KTVF, and KBJI as thunderstorm cells develop and wrap around an upper low over central MN. Convective activity should taper off by early evening. Winds will remain below 10 kts through most of the period. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...JR DISCUSSION...Riddle AVIATION...JR