Expires:No;;321957 FXUS63 KMQT 192251 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 651 PM EDT Fri Jul 19 2019 .SHORT TERM...(This evening through Saturday) Issued at 307 PM EDT FRI JUL 19 2019 ...Potentially Severe Thunderstorms Expected Tonight... Clear skies this morning and afternoon are adding fuel to the fire in terms of convection this evening. GOES-E WV imagery shows an area of mid level dry air between two masses of thunderstorms across MN and lower MI. The 12Z GRB, and to some extent 12Z INL, support this mid-level of dry air which will facilitate any severe wind threat this evening. The MCS across MN has diminished for the most part, with one stubborn cell continuing on. Cloud contamination has begun to find its way into western Upper Michigan in IWD from MCS across MN. Daytime highs and heat indices soared across much of Upper Michigan, with the temperature still climbing at the WFO. ISQ reached the mid 80s prior to the development of a Lake Michigan lake breeze. A light cu field as developed along Lake Michigan where the two lake breezes have converged. This area of convergence does have the potential to pop up a quick shower and thunderstorm or two this afternoon. For tonight, CAMs are in agreement for a complex of thunderstorms developing to the west this evening. As a low pressure moves east into MN, models depict storm initialization around 19-21Z. These storms then appear to track east. Current model analysis shows a CAPE gradient running parallel along the WI border and then into Menominee and Delta counties. Some uncertainty exists on how far north the associated warm front and CAPE gradient extends into Upper Michigan which will play a major factor in how far north these storms make it into the UP. For now, have kept likely chances across the MI-WI border and then chances up into north-central UP tracking east towards the SOO. The atmosphere appears primed for convection as CAPE values reach up to 3000 J/kg depending on the model with bulk shear values 50-60 kts across much of the area. Hodographs show some clockwise turning in the lowest levels, but the majority of shear remains somewhat parallel to the boundary. If any isolated storm forms ahead of the line, all hazards appear likely with SRH values well over 300 to near 500m^2/s^2. Overall, storms appear to become cold pool dominated with all hazards remaining possible, with severe winds becoming most likely. For tomorrow, as the jet and an area of PVA move through the area, light showers and thunderstorms are possible. It appears most will remain south into WI along the right-entrance region of the jet and surface boundary. Enough lift and moisture will remain in the area to leave mostly cloudy skies throughout Upper Michigan, however, temperatures and dewpoints will be much lower than today thanks to a frontal passage. .LONG TERM...(Saturday night through Friday) Issued at 313 PM EDT FRI JUL 19 2019 Models suggest that the quasi-zonal pattern across the northern CONUS will amplify from this weekend into next week as a ridge builds from the sw CONUS into Alberta/Saskatchewan and a downstream trough develops over the eastern half of Canada into the Great Lakes and eastern CONUS. The resulting nw flow on the backside of the trough axis through the northern Great Lakes will bring seasonably cooler and drier air into Upper Michigan this weekend into the early part of next week. Beginning Saturday night, any convection which may refire along the frontal boundary over southern MN and central WI on Saturday with the aid of a passing shortwave could clip the south central CWA on Sat. However, expect any remaining convection to generally slide south of Upper MI by 00Z Sun, with the possible exception of southern Menominee County. Will keep slight chance PoPs in fcst for the early evening for MNM to cover this remote possibility. Min temps should be more comfortable, generally in the 50s with falling dew points. Downsloping locations near the bay of Green Bay may only lower near 60F in light nw flow. Sun-Mon, dry weather will prevail as sfc high pressure builds eastward from the northern Plains. Comfortable July weather is expected with highs in the 70s and lows in the upper 40s to lower 50s. Dew points will also drop into the upper 40s on Sunday and mid to upper 40s on Monday. Tue-Thu, expect increasing temps as the center of the sfc high settles more into the mid-MS and Ohio River Valleys and a westerly low level flow brings warmer air and slightly more moisture into the area. Any weak shortwaves in the nw mid/upper level flow could trigger some isold/sct shra/tsra by Wed/Thu. With limited coverage or upper level forcing, mainly dry conditions will still prevail through much of the week. The pattern deamplifies for late next week with a transition again to quasi-zonal flow across the northern Great Lakes by Friday. Both the GFS and ECMWF indicate a shortwave and associated frontal boundary approaching from the northern Plains late in the day. This system could bring sct shra/tsra into the western half of the cwa by late Fri/Fri evening. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 651 PM EDT FRI JUL 19 2019 Tricky forecast continues as it looks like an MCS will move along the WI border and our area will be on the northern periphery of it this evening. Looks like it would be showers so far with majority of the thunderstorms south. With this in mind, looks like VFR conditions will continue through the period at all sites. There could be some MVFR conditions briefly at SAW overnight. ALso, there could be some LLWS this evening briefly as well at SAW and IWD . && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 307 PM EDT FRI JUL 19 2019 Thunderstorms are possible on Lake Superior tonight, however most are expected to remain south. Patchy fog chances remain across Lake Superior until a cold front passed on Saturday. Winds will approach 20 knots through this evening and a few gusts up to 25 knots for the higher platforms. Gusts up to 25 knots from the west to southwest are possible on Saturday, and then will remain below 20 knots through the rest of the forecast. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JAW LONG TERM...Voss AVIATION...07 MARINE...JAW