Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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210 FXUS63 KFGF 211731 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1231 PM CDT Fri Jun 21 2024 .KEY MESSAGES... - Isolated strong to severe storms possible in Devils Lake region Saturday late afternoon. - Potentially strong to severe storms on Monday afternoon. && .UPDATE... Issued at 1231 PM CDT Fri Jun 21 2024 Kept reducing POPs and took out the mention of showers early afternoon, but still kept showers in for this evening as development may still occur. There is a low cloud layer south of I-94 that may be producing fog or some precipitation as the airport observations are reporting unknown precipitation with various visibility reductions. UPDATE Issued at 1027 AM CDT Fri Jun 21 2024 Most of the FA is seeing filtered high clouds this morning, with the exception of the far south, or along the Dakotas border into adjacent areas of west central Minnesota. Down in that area, there is some lower stratus and fog, although visibilities don`t appear to be less than about 2 to 3 miles. Lowered the forecast cloud amounts to match a little better to these current conditions. Otherwise, not much precipitation is materializing across the southern FA, so will go ahead and lower those chances through the day as well. The latest CAMs are still showing some shower (maybe thunder) development by later afternoon, especially west of the Red River Valley. However, even this seems pretty subtle (no real strong forcing), so confidence is pretty low that too much shower activity will develop today. UPDATE Issued at 653 AM CDT Fri Jun 21 2024 Area of rain and thunderstorms stayed well south of our fcst area overnight and back edge of the rain is roughly Long Prairie MN to Redwood Falls MN. ABR radar shows a few very light showers NW of Aberdeen in an area of lower clouds. Otherwise dry and not seeing much of a chance for organized showers thru early aftn in our south. && .DISCUSSION... Issued at 329 AM CDT Fri Jun 21 2024 ...Synopsis... The jet stream pattern into next week will feature a 500 mb ridge spreading west-southwest over Texas from its position over Kentucky currently. Expect several 500 mb short waves to move through the southern Canadian prairies the next 5 days with each one potentially bringing a period of strong or severe storms. For today into tonight, the axis of strong storms and heavy rainfall has remained well to our south in southeast SD and moving into southern MN. Northern edge of showers with this feature look to brush far southeast fcst area today. There is an additional short wave over Wyoming generating a few storms in SE Montana and NE Wyoming. This wave may bring a few scattered storms into Devils Lake basin or parts of E ND late this aftn/eve. Instability is weak with this so no impacts are anticipated, other than lightning which would occur from any thunderstorm. Heavy rainfall is no longer a threat over the forecast area with rainfall forecasts thru the weekend under one half inch, most under one quarter inch. ...Isolated strong to severe storms possible in Devils Lake region Saturday late afternoon... A separate 500 mb short wave will move from southern Alberta into SW Manitoba by Saturday afternoon. The southern edge of height falls and cooler air aloft with this feature will brush north central ND 21z-00z and CAMS indicate development of a few storms with this, with higher coverage farther north in western Manitoba. Instability is present, with MU CAPES up to 1000 j/kg 21z-00z period in the area east of Minot to the Devils Lake area. ...Potential for strong to severe storms Monday afternoon... A stronger 500 mb short wave will move in a similar fashion from southern Alberta into southwest Manitoba by Monday aftn. This time though the rain and storms will not be present to our south and thus better return flow with SE wind bringing up 60+ dew pts into the high plains Sunday aftn/night. Monday will see upper wave in Manitoba with an eastward progressing cold front that will work into eastern ND 21z-00z time period. Dew pts progged to be 65-70 and MU CAPE values potentially in the 3000-4000 j/kg range due to forecast sfc temps in the 80s to around 90. Warmest and most unstable airmass in SE ND. Capping issues with warming 850-700 mb layer do look to be present and may play a role in potential for thunderstorm development. Bulk shear will be sufficient with values 45-55 kts. Something to monitor the next few days. Supercell composite values forecast from GFS would support supercell discrete cells mid to late aftn that may turn into a larger cluster in the evening. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1231 PM CDT Fri Jun 21 2024 VFR conditions are expected through this evening. There is a streaky layer of low level clouds across the TAF sites that general sits between 3000 and 4000. These clouds are expected to remain thin enough to be scattered but at times may be become dense enough to be broken. The most uncertainty is the development of showers late this afternoon and evening. The environment conducive to produce showers seems very conditional however if showers do develop they would most likely start around 03-04z for KDVL, KFAR, and KGFK. MVFR and IFR may develop tonight after 00z as the models depict clouds below 2000 but not quite sure how feasible that is. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Godon DISCUSSION...Riddle AVIATION...MM