292 FXUS63 KMQT 141714 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 114 PM EDT Sun Jul 14 2019 .UPDATE... Issued at 939 AM EDT SUN JUL 14 2019 MCS in southeast Manitoba is maintaining itself this morning. Given 850-500 thickness/mean flow curving to the SE, expect this MCS could clip western Superior and Gogebic County late this afternoon/this evening. CMC Hi Res and NSSL-WRF are both handling it well and both have it, or new development on its northern flank, over these areas. Therefore, have increased POPs over these areas 21z-03z but only to chance for now. Will continue to monitor today, especially as 12z CAMs start to come in. && .SHORT TERM...(Today and tonight) Issued at 514 AM EDT SUN JUL 14 2019 Water vapor imagery and RAP analysis show a broad mid-level ridge over Rockies and Plains flanked by trofs just off the Pacific NW and over Quebec/New England. Downstream of the ridge, it's been a tranquil cool/comfortable night across Upper MI with sfc high pres over the area. In general, temps across the interior are in the 40s with a few of the traditional cold spots down near 40F. As mid-level ridge expands downstream today, sfc high pres will drift to the e and toward the Lower Great Lakes, allowing southerly winds to take hold. Along with mostly sunny skies, high temps today will generally be 5 to 10 degrees higher than yesterday. Greatest increase in temps over yesterday will occur along Lake Superior as lake breeze will not develop at most locations, and where it does, good warming will occur thru the morning. Guidance today is a little slower to increase dwpts, so we'll get one more day before conditions become uncomfortably humid. Dwpts will mostly be in the 50s thru the day, but readings will increase to around 60F over the far w and at some locations near the Lakes. With a delay in moisture increase, not expecting any late day convection over the w. There will be a shortwave moving from southern Manitoba toward northern Lake Superior, so there may be some convection approaching Isle Royale toward 00z. Guidance has taken a dramatic change with regard to the potential of convection tonight, resulting in a very low confidence fcst. Prior to the 00z model runs, there had been a fairly decent signal in a number of model cycles for shra/tsra to spread across the fcst area tonight in association with a shortwave. Most models are now indicating a dry night. Low-level jet is fcst to be displaced more to the w of here thru much of the night with nose pointing thru northern MN into northern Ontario. So perhaps focus for convective development will be in that area as one possible scenario. With a nw- se oriented 850-300mb thickness field, once convection organizes it should peel se toward Upper MI either late tonight or Mon morning. Even if that is not the case, theta-e advection and building of elevated instability as eastern edge of low-level jet pushes into the area should support some convective development tonight into Upper MI. Rough estimate of effective shear puts it at under 25kt tonight, but with MUCAPE for non sfc based parcels upward of 1500j/kg, there may be some strong storms and isold svr. Will be a warm night tonight under southerly gradient wind and increasing moisture. 60s will mostly be the rule. May not be much blo 70F w and n central as winds will be stirring more in those areas. Temps may slip blo 60F se and e. .LONG TERM...(Monday through Saturday) Issued at 426 AM EDT SUN JUL 14 2019 Quasi-zonal flow will remain across the northern tier of the U.S. and southern Canada through at least the latter half of the work week. Substantial upper ridging and heat dome will build across the Plains thereafter. Overall confidence in the forecast is high with regards to it being very warm and humid...highs 85 to 90 for most and dewpoints approaching 70...through later this week. However, there is very low confidence in the timing of shortwaves and corresponding convective clusters that will move across the Upper Lakes. Most models suggest a shortwave will move across the area during the day Monday with corresponding weak surface trough. The surface trough will then string out from west to east around or just south of the U.P. and as additional weak disturbances move eastward through mid to late week several rounds of convection could affect the area. While much of the time will be rain free...and thunderstorm clusters that do develop will be efficient rain producers with PW values between 1.75 and 2 inches through at least Thursday. While it is difficult to pin point where the heaviest rains will fall this week, the potential exists for some locations across the U.P. to see over 2 inches of rain this week. While the heavy rain with any storms this week will be the bigger concern..any well defined MCSs that develop and move into the area will have a marginal severe wind threat. By late in the week...the GFS and ECMWF vary with the degree of upper troughing that will develop over the eastern Great Lakes and northeast downstream of the building central U.S. ridging. A blend between the ECMWF and GFS seems the best course of action which will mute the more substantial low level drying and cooling across the Upper Lakes as depicted by the GFS. && .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) Issued at 113 PM EDT SUN JUL 14 2019 Mostly clear skies expected next 6-9 hours at the TAF sites (except for fair weather cu this afternoon). After that confidence decreases significantly. In general, will see mid to high clouds building in from southwest (but staying VFR), winds increasing with 20 knot gusts possible, and SHRA or TSSHRA developing late tonight into tomorrow. Hard to pin down where and when showers and storms will develop at this point so have kept only VCSH in at this time. Any heavy showers and storms tomorrow could briefly cause category reductions in cig and/or vis as well as locally gustier winds. && .MARINE...(For the 4 AM Lake Superior forecast issuance) Issued at 514 AM EDT SUN JUL 14 2019 Winds are expected to be mostly under 20kt thru midweek. Stronger winds would be more likely tied to any complexes of showers and thunderstorms that track across the Upper Lakes. Once showers and storms move over the lake, expect fog to develop, and it will likely become dense in some areas. The fog will likely plague the lake for most of the week once it develops. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ UPDATE...RJC SHORT TERM...Rolfson LONG TERM...MZ AVIATION...RJC MARINE...Rolfson