Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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970 FXUS63 KFGF 241503 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1003 AM CDT Fri May 24 2024 .KEY MESSAGES... - Will keep monitoring impacts of rain from Thursday and additional rain today for rises on area rivers. - Temperatures today in Cando-Langdon areas from model data seem hard to believe as HRRR drops them into the mid 30s midday and aftn. Kept hourly temps a tad warmer upper 30s and rain in the fcst. - Low temps below 36F possible in northeast ND late tonight/early Saturday. Confidence not yet high enough to issue any frost headlines. && .UPDATE... Issued at 1003 AM CDT Fri May 24 2024 Rain continues to rotate around the upper low, with the dry slot starting to move into our far southwestern counties. The precipitation forecast seems on track and only minor tweaks needed. Winds at Detroit Lakes gusted up to 55 mph around 915 AM, but came back down and have been the only spot in our area near wind advisory criteria. Winds in that area should come down as the center of the surface low approaches in the next few hours. At this point, think the best chances for wind advisory winds will be in southeastern ND later on this afternoon on the backside of the low where they will have the extra push of height rises and cold air advection. However, still borderline and will hold off on any headlines for the moment and see how winds develop as we head into the afternoon. UPDATE Issued at 721 AM CDT Fri May 24 2024 Forecast going as anticipated. Upper low in far north central SD at 12z with sfc low between Aberdeen and Bismarck. Both lows will track northeast today and be near Pembina ND region by late in the day. On the southeast and east side of upper low as surface boundary moves around the low, will need to monitor for funnels or if increased instability low topped supercell hazards. This would be I think timing wise more in the mid RRV and parts of MN ESE from GFK to Mahnomen region. && .DISCUSSION... Issued at 340 AM CDT Fri May 24 2024 Upper low in northwest South Dakota with surface low east of Hettinger ND at 08z. The upper low and sfc low will move northeast today and be just west of Grand Forks at 18z and be near Pembina ND at 00z. The initial area of rain and thunderstorms has moved thru most of the the Red River valley and now into south central Manitoba. Deformation rain band is from SW Manitoba thru the Turtle Mountains, Minot to Dickinson area into parts of western SD. Looking to our south another surge of showers and a few t-storms is moving north-northeast thru SW Minnesota and far eastern South Dakota. This area of moisture will spread into the Red River valley and thru NW/WC MN during the course of the day as rain wraps back around the system into central ND. A few things to consider today. Track of upper low just west of GFK and surface low near GFK early to mid afternoon will put the mid RRV in a favored spot for potential low topped thunderstorms, Canadian GEM has about 500 mb MU CAPE into the Grand Forks area early this afternoon, with GFS and other short term models a bit weaker more like 100-200 j/kg. Unless some sunny breaks occur and allow temps to warm just east of the upper low early this aftn, unsure if enough instability will be realized for low topped supercells. May be more showers, weak t-storms. But with upper level low and sfc low nearby and potentially a weak cold front swinging north around the low, some sfc vorticity. This pattern does look like prev patterns when funnels have occurred. Uncertainty is too high to message this in social media, but worth mentioning in this forecast discussion. I would peg the chance for conditions favorable for funnels to be 40 pct. Winds on the backside of the system will br near advisory levels, with strongest mixing south central ND into central SD. Though a period of potential wind gusts near 45 kts is possible into SW fcst area 21z-00z period today. Coord with ABR and BIS and for SE ND will not issue a wind adv at this time since stronger wind potential is not til late today and the situation can be evaluated further during the dayshift. What has me scratching my head the most is model insistence that temps will drop into the mid 30s in north central ND and parts of Devils Lake/Langdon areas this aftn with rain mixing or even changing to snow some models suggest. I have a tough time with this degree of cooling as there is no source of that cold of an airmass anywhere close and dew pt/temp differences are already at 0-1C so not like there is evaporation cooling involved. HRRR temps would be the coldest. NBM temps used in fcst would have upper 30s and rain in that area. Something to monitor for sure. If any place would get wet snow later today it would be higher terrain of the Turtle Mountains. But also I always recall many times the Langdon surprise as it cools there more than anywhere else it seems. Tonight....how cold will it get. There is no big high moving in and potential for scattered clouds at least and some wind. NBM lows showing 31 in Towner county seem too aggressive, so kept coldest temp at 32 in NW fcst area. Frost tool gives no frost due to cloud/wind potential. My confidence in lows below 35 in Devils Lake-Langdon area is about 50 percent and for lows to 32F about 20 percent. Just not enough confidence yet to issue any frost advisory for areas with low temps below 36F at this time. BIS agreed. Saturday into Monday will feature a broad 500 mb east-west trough over the area. Some weak embedded short waves with enough sfc heating in the aftn to generate a few hundred CAPE and a chance for a few showers each day. Tues-Wed should see an upper ridge build in temporarily and temps warm some, before a possible next 500 mb wave moves in late next week. && .AVIATION /12Z TAFS THROUGH 12Z SATURDAY/... Issued at 721 AM CDT Fri May 24 2024 Aviation is VFR cloud bases RRV and MN east of the advancing low pressure system that will move to just west of GFK to near Pembina by late today. Rain bands will move northwest and around the low and in these rain bands in the RRV and MN some brief MVFR or IFR conditions in vsby or ceilings possible. Most widespread IFR ceilings DVL basin. Some lower ceilings likely to spread southeast or east as low passes by late tonight into this evening. Gusty winds today and changing winds, from more east to southeast RRV and MN then to the west late aftn/eve as low moves by. Winds turning northwest DVL and gusty all day. Potential for gusts 35 kts at any one TAF site. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Riddle/JR DISCUSSION...Riddle AVIATION...Riddle