Area Forecast Discussion
Issued by NWS Twin Cities, MN
Issued by NWS Twin Cities, MN
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155 FXUS63 KMPX 291755 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 1255 PM CDT Sat Jun 29 2024 .KEY MESSAGES... - Cooler and dry this weekend will help as area rivers remain high from recent rainfall. - Rain returns to the forecast Monday into Tuesday. - Independence Day forecast continues to look wet. && .DISCUSSION... Issued at 307 AM CDT Sat Jun 29 2024 This weekend... Early Saturday morning a small chance for rain remains as a cold front passes through. So far there has been little activity along the front. Some CAMs like the HRRR continue to suggest that some activity will form along the front in central Minnesota. However there is little sign of this occurring so far in observations and without the typical strong LLJ that would typically drive this type of rain, it remains unlikely. With clear skies and moist air ahead of the front we have seen some patchy dense fog. This has been most likely in low lying areas and near bodies of water. Since it has been localized so far no advisory has been issued. The rest of the weekend`s weather will be driven by the high pressure moving into the Upper Midwest from the Northern Plains. This will bring mostly clear skies and cooler air for the rest of the weekend. Monday and Tuesday... The weekend high pressure will move east across the Great Lakes on Sunday night allowing for a shift in the weather. Warmer and moist air will advect into the Upper Midwest on Monday. With this moisture cloud cover will return, which could limit how much we actually warm up on Monday. This warming could be further limited by evaporative cooling from expected rain. With forcing from a shortwave aloft and a potentially favorable location of the jet streak we will likely have the forcing for another wet period. This is supported in the NAEFS as we have above the 99th percentile PW and IVT suggesting that we will have plenty of moisture to work with. This will be from Monday into Tuesday with a two day period of rain chances. It will be up to the mesoscale, which still has a fair amount of uncertainty on where and when during the two days the bulk of this rain will fall. However, as discussed above, the synoptic setup is favorable for rain. How soon rain will form will be important in the chances for any strong to severe storms. The SPC has a slight (2 of 5) risk across western MN with a marginal (1 of 5) risk to east extending to around Eau Claire, WI. If significant rain can form early in the day that could limit the instability for later in the day limiting the chances for CI. A drier start to Monday would increase the chances for strong storms later in the day. Another shortwave moves in on Tuesday driving a second day of rain chances. More rain is expected, but with the continued WAA there is a chance that a stout cap could form limiting the chance for convection (therefore the chance for severe and heavy rain could be limited). This cap is seen in some, but not all model solutions. On the heavy rain and flooding threat side of Monday and Tuesday there remains a wide spread in the ensemble QPF right now as one would expect this time of year thanks to convection being the primary driver of heavy rain. It won`t be until later in the weekend that we get a better idea of the mesoscale setup such that we will better know where the heaviest rain will fall. Wednesday through Friday... We look to have a brief dry period mid week before another wave moves over us bringing with it another chance for rain. This would be on the 4th into the 5th possibly giving us a wet Independence Day. Pretty good confidence in the ensembles that rain will occur, but how much and what time still has notable spread. As the last discussion said we are still a few days out from having confidence on the details here. Beyond this system through there is some sign in guidance that we might get a more prolonged period of drier weather as the more active part of the upper pattern shifts to the north into Canada. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1244 PM CDT Sat Jun 29 2024 Until sunset, we`ll maintain northwest winds at their current speed, with cigs continuing to slowly rise, with mainly VFR cigs expected by 21z. An isolated shower or two is possible east of MSP, but coverage is expected to be low enough to preclude a mention of precip at any terminal. For fog potential tonight, we`ll have the clear skies and calm winds, but incoming airmass looks to be dry enough to prevent fog from forming. The lone exception being along the river there at EAU. KMSP...Given the MN River now resembles a lake, there could be some fog down in the valley Sunday morning, but this is not expected to impact MSP. We will see a wind shift Sunday morning from the north over to the southeast, but speeds will be 5 kts or less while this is happening. /OUTLOOK FOR KMSP/ MON...VFR. Chc MVFR/-SHRA day, MVFR/TSRA likely overnight. Wind SE 15G25 kts. TUE...MVFR. Chance MVFR SHRA/TSRA. Wind SW 10-15 kts. WED...VFR Wind WSW 15G25 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION... AVIATION...MPG