


Area Forecast Discussion
Issued by NWS Twin Cities, MN
Issued by NWS Twin Cities, MN
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572 FXUS63 KMPX 140837 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 337 AM CDT Mon Jul 14 2025 .KEY MESSAGES... - Warm & humid today & tomorrow. - Thunderstorms expected Tuesday evening through Wednesday. Locally heavy rain is likely in addition to a chance for severe storms Tuesday evening. - Additional chances for thunderstorms this weekend into early next week. && .DISCUSSION... Issued at 256 AM CDT Mon Jul 14 2025 Relatively quiet night across the area with a few lingering showers across western Wisconsin, & the latest surge of Canadian wildfire smoke remaining limited to northern Minnesota & Wisconsin. Temperatures will warm a few degrees compared to yesterday with highs around 90 expected, but strengthening southerly flow will bring muggier dewpoints by this evening. This will create a rather unstable atmosphere by this evening with more than 3000 J/kg of surface-based CAPE expected to develop, however weak forcing along a diffuse surface boundary will be tough to overcome capping aloft with 700 mb temperatures nearing 10 C. One or two isolated thunderstorms can`t be ruled out however, most likely across western Wisconsin where capping will be weaker. Another warm & humid day is expected Tuesday as southerly flow continues to increase ahead of a slowly advancing cold front out of the Dakotas. Compressional warming along the front may boost temperatures into the low to mid 90s across much of eastern & southern Minnesota & western Wisconsin, while precip & cloud cover from the front could limit temperatures to the 70s across central Minnesota. This precipitation during the day is not expected to be very heavy or widespread, but thunderstorms will become more robust Tuesday evening as upper level forcing from a passing shortwave increases. Another unstable environment will develop ahead of the front by Tuesday afternoon with 2500-3000 J/kg of surface-based CAPE, but only around 20 kts of deep shear meaning any strong to severe storms Tuesday evening will likely be short-lived. Also likely limiting our severe p[potential will be that the evening precipitation looks to be largely anafrontal, or occurring behind the surface cold front, meaning it likely won`t be able to fully tap into that unstable environment. More concerning is the threat for locally heavy rain, as multiple rounds of thunderstorms are expected as the front slowly moves through the area through Wednesday. The atmosphere will be primed for efficient rainfall as precipitable water values peak around 2" along the front. Extended-range high resolution models already depict areas of 3-4"+ of rainfall, highlighting the locally heavy rainfall potential, but we won`;t know exactly where these areas will be until we start seeing where storms develop tomorrow night. The good news is that this does not appear to be a classic training thunderstorm type of set up, more like multiple rounds of slow- moving thunderstorms that will likely impact a few locations more than once from Tuesday evening through Wednesday morning. Outside of those locally-enhanced amounts of 3-4"+, widespread amounts of around 1.5-2" are generally expected across central Minnesota, tapering down to 0.5-1" across southern Minnesota. Precipitation should be exiting the area Wednesday afternoon, with mostly dry weather expected into Friday as high pressure passes over the region. Temperatures will be seasonably cool as well with highs Wednesday & Thursday only in the upper 60s to low 70s. Still a little too early to have a good handle on the potential for air quality impacts from additional wildfire smoke, but at least some smoke in the region looks likely given the northwesterly flow aloft. The flow aloft becomes more active this weekend into next week, with a few shortwaves likely giving us chances for thunderstorms. Blended model guidance PoPs give us generic ~30% chances for rain during this entire period, but this is an artifact of timing differences among models. Thunderstorm chances generally look most likely sometime Saturday, & then again Monday into Tuesday with near- normal temperatures. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1051 PM CDT Sun Jul 13 2025 The main issue in this duration will be the return of near- surface smoke during the day Monday. Another wave of Canadian wildfire smoke, likely the last one before a midweek cold front, will move into the region after daybreak tomorrow and will likely reduce all sites to MVFR-range visibility. In addition, mid-level diurnal cumulus clouds are likely to develop tomorrow but be relatively insignificant. SW winds around 10kts will go light/variable overnight before picking up from the SE at 5-10kts after sunrise tomorrow. Should winds go calm close to sunrise, there is a period of ground fog possible which could produce low MVFR to IFR visibilities at the WI TAF sites. KMSP...VFR through the overnight hours, then MVFR-range visibility due to Canadian wildfire smoke is expected during the daytime hours Monday. Otherwise, no issues. /OUTLOOK FOR KMSP/ TUE...VFR, TSRA likely evening/overnight. Wind SW 10-15 kts. WED...MVFR, chc IFR/-TSRA. Wind NE 5-10 kts. THU...VFR, Wind NE 5-10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...ETA AVIATION...JPC