Area Forecast Discussion
Issued by NWS Twin Cities, MN
Issued by NWS Twin Cities, MN
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159 FXUS63 KMPX 231813 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 113 PM CDT Thu May 23 2024 .KEY MESSAGES... - Warmer temperatures return today with thunderstorms and showers developing ahead of a cold front this evening. A few storms could be strong to severe tonight. - Seasonable temperatures through the Memorial Day weekend with a few chances of showers through early next week. && .DISCUSSION... Issued at 357 AM CDT Thu May 23 2024 TODAY... The pattern remains active for the near term with a shortwave trough ejecting out of the northern Rockies. This leads to a sub 1000mb sfc low pressure approaching Minnesota from the Dakotas tonight. This will set the table for another round of showers and thunderstorms across western and central Minnesota. At the surface, warm front will move north through the region today allowing temperatures to rebound into the upper 70s and lower 80s. One thing to keep an eye out for this afternoon is the potential for a few isolated showers/storms popping up in the diurnal cumulus field across central Minnesota. These storms will likely stay sub-severe, but gusty winds and small hail. Most should stay dry throughout today. Additional development is expected along and ahead of the approaching cold front over the Dakotas this evening. The main concern with how intense these storms will be as they approach W MN given the limited instability in place ahead of the line. Timing is also working against it as these storms are forecast to move through late evening through Friday morning. There will be a LLJ that will aide in moisture and elevated instability advection. Storms may take a more linear appearance allowing them to maintain some organization into Friday morning. If we look at the hires guidance, forecast soundings aren`t exactly screaming severe potential. Instability will be modest at best, but the one positive will be the shear profile. Forecast hodographs show a sickle shape with increasing speeds with height across W MN after sunset. If storms organize into a more linear complex, damaging wind potential will be higher vs cluster convective mode. SPC`s day 1 SWO Marginal (1/5) is reasonable considering the favorable shear environment limited by modest instability during the diurnal minimum. QPF amounts of 0.25 to 0.50" are likely with locally higher amounts by Friday AM. FRIDAY THROUGH WEDNESDAY NIGHT... Guidance signals that the pattern should remain somewhat active into the middle of next week. On Friday, the focus shifts to the next shortwave emerging from the mid- level troughing across the western CONUS. The first shortwave lifts NE through the central Plains into the northern Great Lakes, eventually swinging into Manitoba and Ontario. Saturday for the most part should be dry with ridging/subsidence behind the exiting shortwave. Broad isentropic ascent spawn showers that`ll move across southern Minnesota. Forecast soundings show very limited instability so only isolated t-storm coverage at best. Temperatures will remain seasonable, in the 60s and 70s, but temps begin to warm by the end of the long term forecast period (next thursday). QPF amounts should remain on the lighter side, generally 0.25" or less, through Sunday night. Model spread and uncertainty ramps up for Memorial day onward regarding the next shortwave to eject from the western US. Have continued to lean on the NBM rain chances, given the degree of spread present with generally 30 to 60% rain chances Sunday/Memorial Day. This uncertainty means those of us with holiday weekend plans will have to pay attention Sunday night into Monday for possible impacts. Looking ahead towards the middle of next week most guidance seems to be in general agreement showing a trend toward ridging building in and drier conditions for Tuesday and Wednesday next week. We will have to monitor the latter half of the forecast due to the increased uncertainty in placement of any shortwaves moving through the mid- level trough over the western CONUS. As a result, low end rain chances exist into Wednesday night into Thursday. Temps should be fairly seasonable for late May/early June. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 102 PM CDT Thu May 23 2024 VFR conditions into this evening with FEW/SCT cumulus through sunset. Thunderstorms are expected to develop across eastern ND & northwest MN by late this afternoon, with a low (10-20%) of a thunderstorms developing far enough south to impact AXN by early evening. Otherwise, a line of showers & thunderstorms will move into Minnesota after midnight, reaching eastern Minnesota by sunrise & western Wisconsin by 7-8 AM. Thunder chances are highest across southern Minnesota (MKT) but will include a PROB30 at RWF/MSP/RNH/EAU for 2-3 hours tomorrow morning. Visibility is mainly expected to be borderline MVFR/IFR during the showers tomorrow morning, with periods of IFR possible during thunderstorms. Ceilings will also lower as the rain begins & linger into at least mid-morning, with most terminals expected to see a few hours of MVFR tomorrow morning. Winds will generally be southerly to southeasterly this afternoon with speeds around 10 kts. Winds become predominately southeasterly this evening & overnight with gusts of 20-25 kts developing as the rain begins. A wind shift to southwesterly is expected after the rain ends, with gusts around 20 kts remaining through the morning. KMSP...Showers and thunderstorms could begin as early as 5 AM, but 6-7 AM is the more likely start time as of now. A few rumbles of thunder are likely, but will wait for confidence on the thunder chances to increase before going prevailing TSRA in the TAF. /OUTLOOK FOR KMSP/ SAT...VFR. Wind SW 10 kts. SUN...VFR. Chance -SHRA/MVFR. Wind E 10-20 kts. MON...VFR. Chance -SHRA/MVFR. Wind NW 10-20 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...BPH AVIATION...ETA