Area Forecast Discussion
Issued by NWS Marquette, MI
Issued by NWS Marquette, MI
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872 FXUS63 KMQT 151932 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 332 PM EDT Sun Sep 15 2024 .KEY MESSAGES... - Isolated non-severe showers and storms into early evening along a narrow corridor from Iron through Baraga and western Marquette counties. - Extended stretch of well above normal temperatures continues through the forecast period with highs mainly in the upper 70s and 80s. && .SHORT TERM /THROUGH MONDAY NIGHT/... Issued at 331 PM EDT Sun Sep 15 2024 Despite large scale high pressure dominating much of the Great Lakes and northeast CONUS, water vapor imagery does show a connection to Gulf of Mexico/Atlantic moisture into the Upper Great Lakes region this afternoon. This moisture connection has allowed surface dew points to climb into the mid 60s across much of the west half of the U.P. this afternoon. MLCAPE values near 1000 j/kg and minimal to no capping noted on soundings has led to the initiation of a few showers and isolated t-storms over central Iron County early this afternoon at the nose of the sfc theta-e ridge. A few of the CAMs suggest isolated showers could continue into early evening along a fairly narrow low-level convergence zone and theta-e ridge axis extending from Iron into Baraga and nw Marquette counties. With weak wind shear, none of these storms will become strong or severe but could produce brief heavy downpours. After showers die out over central Lake Superior tonight with loss of diurnal heating, much of the rest of the night should be quiet under the dome of high pressure. Models hint that some convection could reinitiate into north central MN at the nose of a weak LLJ this evening, and then possibly advect into the western U.P. toward 12Z Monday, but given model uncertainty with this happening only have slight chc pops barely reaching into the far western U.P. toward sunrise. Given high dew points over the area it`s also not out of the question that patchy fog could form at a few locations, especially where showers occur. Expect min temps tonight ranging from the mid 50s to mid 60s under partly cloudy skies. && .LONG TERM /TONIGHT THROUGH SATURDAY/... Issued at 308 AM EDT Sun Sep 15 2024 BLUF: Mainly calm weather dominates the extended period, although some light rain showers and some thunderstorms are possible over the west tonight and Monday. Expect the late summer-like conditions to continue through the week, although temperatures may slightly decrease late this week as troughing approaches from the west by next weekend. Therefore, if you can, enjoy those outdoor activities while you still can! Some isolated rain showers and a thunderstorm or two are possible over the western U.P. late tonight through Monday as a shortwave riding along the ridging over the Great Lakes moves overtop us. While plenty of instability is available in the atmosphere by the Monday afternoon hours, with the better forcing located to our west and north, rain showers and storms will have a difficult time firing up. Therefore, any convection that we do see late tonight through Monday will more than likely be dependent on hard to pin down mesoscale/local variables, such as storm dynamics and localized topography. With the better PWATs further to our west and north too, not much rainfall is expected to fall out of the showers and storms we do see; expect no more than a quarter of an inch in the heaviest rain spots, with many areas even over the west failing to receive anything. Expect the rest of this week to be dry as high pressure ridging settles across the Upper Great Lakes while troughing digs into the western U.S.. While the warmest day is expected on Monday with highs possibly getting into the mid to upper 80s in the interior areas, the rest of the work week is very likely (80+%) to see high temperatures in the upper 70s to lower 80s, with mostly sunny skies dominating overhead due to the ridging. Fire weather concerns should be limited this week due to the light winds and more "moist" min RHs. However, fuels may need to be monitored as the lack of rainfall could further dry them out. By next weekend, model spread increases amongst the differing suites. However, there is still a general trend to push the timing of incoming rainfall back to the end or past the end of the extended period. Therefore, I`m highly doubtful (80+% chance) that we will see rainfall over our area until at least early next week. However, we could see cloud cover increase from the west as the troughing slowly tries to battle its way into our neck- of-the-woods this next weekend; this increase in clouds would drop our daytime high temperatures closer to normal. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 727 AM EDT Sun Sep 15 2024 VFR will prevail thru this fcst period at IWD/CMX/SAW. Some scattered showers and isolated storms could develop between CMX and SAW this afternoon but should not have much impact on either site before dissipating out over Lake Superior this evening. Some showers could redevelop toward 12Z Monday into the west and could reach into IWD but this probability is too uncertain at this time to include in the TAF. Expect southerly wind gusts to 20 knots at IWD this afternoon. && .MARINE... Issued at 202 PM EDT Sun Sep 15 2024 Light winds of 20 knots or less continue through this week as ridging remains over the Upper Great Lakes. Nevertheless, we could see a few showers and thunderstorms over Lake Superior today through Monday as some shortwave action rides along the ridging overtop us. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Voss LONG TERM...TAP AVIATION...Voss MARINE...TAP