FXUS63 KMQT 262229 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 629 PM EDT Sun May 26 2019 .SHORT TERM...(This evening through Monday) Issued at 406 PM EDT SUN MAY 26 2019 Water vapor imagery and RAP analysis show a trof over the western CONUS, featuring a deep mid-level low over central CA. Shortwave ejecting from this trof across southern AZ will be a feature of interest for the weather here on Memorial Day. Downstream from the trof, a ridge is over the Gulf Coast States. To the n, a trof is over central into se Canada. Within this trof, a shortwave swinging across northern Ontario is pushing a cold front s across Lake Superior and into Upper MI this aftn. Despite the convergence from front and active lake breezes this aftn, very little instability and slight warm nose/weak capping inversion has only allowed for relatively flat cu development, and this cu has been spreading out with time. In the confluence zone btwn the Gulf Coast ridge and the Canadian trof, axis of 100+kt upper jet runs from far southern Manitoba across northern Ontario, just n of Lake Superior. Right entrance upper divergence associated with this jet and mid-level fgen down at the mid levels is supporting sct -shra across far southern Manitoba e along the MN/Ontario border region. Tonight, aforementioned upper jet will increase to 130kt. Right entrance of this upper jet along with low-mid level fgen will continue to support some -shra off to the nw. Approach of a northern stream shortwave, currently over se Saskatchewan, should give a boost to -shra development late tonight/Mon morning. Most of the models capture this idea and streak a band of -shra across nw Lake Superior and the Keweenaw late tonight and Mon morning. Seems reasonable and will include chc pops for now. Whether these -shra survive ese into eastern Alger/Luce Counties Mon morning is less certain as forcing weakens with time. During Memorial Day, attention then turns to the shortwave over southern AZ. As this waves lifts to the Upper Mississippi Valley/western Great Lakes by evening, it will spread a shield of shra toward Upper MI. Given the upper confluence zone over the northern Great Lakes, there is uncertainty in how far n the pcpn will spread. At a minimum, agreement is good for s central Upper MI to see shra arrive in the aftn. Likely to categorical pops will be utilized there. Will then shade pops down to schc/low chc n. Keweenaw may not see any additional pcpn after the sct morning shra. As for temps, 40s will be the rule tonight though a few spots n central may dip just blo 40F. Clouds and easterly winds will make for a notably cooler day on Memorial Day. Expect 40s near Lake Superior in areas exposed to an easterly wind across the lake and only 50s elsewhere. .LONG TERM...(Monday night through Sunday) Issued at 300 PM EDT SUN MAY 26 2019 The long-wave pattern over the CONUS beginning Monday night continues to depict persistent ridging over the southeast and Gulf of Mexico, with a closed low slowly working it's way east across the west. Previously, this feature was expected to weaken and transition to an open wave, crossing the western Great Lakes Wednesday into Thursday. The trend now is for a slower transition and it is now expected to reach Upper Michigan on Thursday or perhaps Thursday evening. With preceding shortwave activity now likely to pass mainly to our south, medium/long-range forecast models have continued to trend drier through the middle of next week for our area. After the trough passes, models depict split flow over the NW CONUS and a NW flow regime for us, with cooler temperatures and chances for showers and thunderstorms with an embedded shortwave currently forecast to push through on Saturday. Rainfall is still expected to be ongoing Monday evening, mainly across the southern tier of counties. This shortwave will be weakening as it moves east and rain will come to and end before sunrise Tuesday. Total precipitation accumulation will range from <0.1" near the Lake Superior shores to perhaps as much as 0.7" near Menominee, with most locations receiving between 0.1-0.4". Afterwards, weak surface ridging will take over and conditions will remain dry Tuesday and Tuesday night, although clouds may be slow to clear if at all, especially south. A weakening shortwave early Wednesday morning will be pushing northeastward through the southern half of Wisconsin, and while most data suggest that this will remain to our south, the 12Z ECMWF does bring some showers into the far southern portions of the UP and the forecast does include this possibility. Besides that, generally dry, seasonal conditions can be expected into Thursday morning. As the closed western CONUS low begins to open and lift across the western lakes, general agreement is that the main area of forcing will be rapidly weakening and likely passing to our south and east Thursday. The next chance for wet weather will come as early as late friday night but likely into Saturday as longwave troughing intensifies south of a closed Hudson Bay low and a cold front approaches from the north. There may be chances for some embedded thunder with this but available buoyancy is questionable at this time. Cooler temperatures will filter in for next weekend. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 629 PM EDT SUN MAY 26 2019 Drier air will linger in the lower levels thru most of this fcst period, allowing VFR conditions to prevail at KIWD/KCMX/KSAW. By Mon afternoon, rain will start to move in and allow MVFR conditions to settle in. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 406 PM EDT SUN MAY 26 2019 Cold front dropping s across Lake Superior will bring a surge of ne winds gusting to 20-30kt for a few hrs this evening over western Lake Superior. Over the e half of the lake, winds will remain under 20kt tonight. As a disturbance lifts ne toward the Great Lakes on Mon, expect ne winds in the 15-25kt range over western Lake Superior. Some gusts to 30kt are possible. Winds will be under 20kt across the rest of the lake. It then appears that winds should be generally under 20kt thru the mid and late week period. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Rolfson LONG TERM...KCW AVIATION...07 MARINE...Rolfson