


Area Forecast Discussion
Issued by NWS Marquette, MI
Issued by NWS Marquette, MI
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908 FXUS63 KMQT 131846 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 246 PM EDT Sun Jul 13 2025 .KEY MESSAGES... - Wildfire smoke from Canada will be over the area through at least Monday resulting in air quality concerns and reduced visibility. - 20% chance of a shower or storm in the far western UP tonight between 8 pm and 1 am EDT. Any storms that occur are capable of gusty winds and hail. - Periods of rain and thunderstorms are expected Tuesday (20-50% chance; highest north/west) and Wednesday (50-80% chance). - Seasonably warm Monday and Tuesday, then sharply cooler Wednesday into Thursday. && .SHORT TERM /THROUGH MONDAY/... Issued at 245 PM EDT Sun Jul 13 2025 Early afternoon water vapor imagery and RAP analysis shows broad midlevel troughing over the northern Plains and upper Great Lakes. A weak impulse in NW flow is near the Grand Forks, ND area, with an attendant surface trough cutting NE to SW across western ON and the Dakotas. A seasonably dry airmass is in place over the UP with PWATs around 0.8", and just some fair weather cu across portions of the UP. This evening, as the midlevel impulse and surface trough approach from the west, moisture pooling ahead of this feature is expected to result in a broken band of showers and storms developing over the Minnesota Arrowhead moving SE. Consensus in the CAMs is for this activity to weaken as it crosses western Lake Superior, with about a 20-30% chance of some showers/storms surviving into far wester portions of the UP in the 8p-1a EDT frame. Severe weather threat is low given marginal instability of 750 J/kg MUCAPE or less (per HREF mean), but a gusty storm with hail can`t be ruled out with dry air at low-levels and 35-40kt of deep layer shear. Otherwise, fairly mild tonight with SW flow ahead of this trough, with lows mainly in the 60s. Monday is forecast to be seasonably warm with highs ranging through the 80s, and little to no evidence for precipitation chances with flat zonal flow aloft and little to no instability. An isolated shower can`t be ruled out along lake breezes near Delta/Schoolcraft with some enhanced low-level moisture pooling there, but less than 20% so will not mention. Wildfire smoke will continue to plague the area through Monday. The HRRR-smoke model suggests the smoke dissipating somewhat tonight after the trough passage, but another plume is expected to follow Monday. Air Quality Alerts remain in effect per MI EGLE. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Issued at 245 PM EDT Sun Jul 13 2025 Flat zonal flow over the northern tier of the CONUS to start the week will amplify with time as a shortwave trough, as an extension of a deep Hudson Bay low, will shift eastward across the northern Plains midweek and into the Great Lakes by the end of the week. At lower levels, a warm front will extend northeast from a low in the central High Plains, sagging southward with time as high pressure builds in behind it. The placement of this front in the vicinity of the local area will be the main driver of impactful weather through the midweek period. Tuesday, model consensus suggests we will be mainly on the warm side of the front, and with 850 mb temps averaging around 16C (+1 to +2 sigma), this will be the warmest day of the week. Highs are expected to be in the mid to upper 80s (except perhaps for the Keweenaw which will be cooler in closer proximity to the front and possible rainfall), and with dewpoints approaching 70F, this could result in heat indices in the lower 90s. Instability will likely be quite healthy in this warm airmass, with the 06Z REFS mean indicating 1-2 kJ/kg by 18Z Tue. Thunderstorm potential will be maximized north of the area in closer proximity to the front and lower midlevel heights, but it`s possible that the front sags south far enough to touch off some convective activity in the afternoon, especially over the north/west. There likely exists some severe potential if this occurs given the instability, although model consensus suggests deep- layer shear may be on the weak side at less than 30 kt. The low-level front continues to linger in the area Wednesday into Thursday, with consensus supporting the surface portion of it sagging mainly south of the area. This will result in sharply cooler temperatures by Wednesday, with highs stuck in the 60s (and maybe even 50s closer to the still below-normal temperatures of Lake Superior) over most of the northern half. Additional rounds of showers and perhaps thunderstorms are expected along the front, especially Tuesday night into Wednesday. Some areas could see heavy rainfall if repeated rounds develop. The pattern largely supports this, with mid/upper level winds largely parallel to the slowly- moving lower-level boundary, and PWATs around 1.5 (+1 to +2 sigma). Gradual drying trend for the end of the week as high pressure builds in the wake of this front, with temps likely rebounding closer to normal Friday into Saturday. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 105 PM EDT Sun Jul 13 2025 Wildfire smoke continues to result in prevailing MVFR vsby this afternoon, which is expected to largely continue into tonight. While there may be a brief respite in the smoke and reduced vsby tonight, another plume is expected to spread into the UP from the west on Monday morning. VFR cigs are expected to prevail through the TAF period. A weakening area of showers and perhaps a few embedded thunderstorms will approach IWD in the 01-05Z timeframe; PROB30 for TS added here. Probability of TS is around 20% at CMX in the same timeframe and near zero at SAW so mention was not included in the TAFs for those terminals. && .MARINE... Issued at 903 AM EDT Sun Jul 13 2025 Visibility will continue to be reduced in areas of fog and wildfire smoke into Monday. Winds will increase with west-southwesterly gusts around 20 kt through today, mainly over the western half. A weakening band of showers and thunderstorms is possible over the western lake this evening (40% chance). Winds diminish early in the week, but could increase to near 20 kt from the north late in the week behind a frontal boundary. Unsettled weather returns Tuesday/Wednesday with additional rounds of showers and thunderstorms possible, plus the potential for fog where rainfall occurs. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Air Quality Alert until midnight EDT /11 PM CDT/ Monday night for MIZ001>007-009>014-084-085. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Thompson LONG TERM...Thompson AVIATION...Thompson MARINE...Thompson