####018004886#### FXUS63 KAPX 160958 AFDAPX Area Forecast Discussion National Weather Service Gaylord MI 558 AM EDT Fri May 16 2025 .KEY MESSAGES... - Warm, dry, and somewhat windy conditions results in elevated wildfire danger today. - Another round of showers and embedded thunderstorms tonight. - Cool weather and cloudy skies return this weekend. High pressure continues quiet weather through the midweek. && .SHORT TERM /THROUGH TONIGHT/... Issued at 321 AM EDT Fri May 16 2025 Pattern Synopsis/Forecast: Occluded front, tied to deep low pressure spinning across the northern Plains, sweeping rapidly east across the area early this morning. Band of decaying showers and embedded thunderstorms along and just ahead of this front, with aggressive dry slot punching in just behind it. Front will exit stage right early this morning as dry slot overspreads the entirety of northern Michigan today. Upstream low pressure and secondary cold front make a run at our area tonight, drumming up another round of showers and perhaps some embedded thunderstorms in the process. Primary Forecast Concerns: Temperature/wind/relative humidity trends today (focus on fire weather concerns) and showers and thunderstorm evolution tonight. Details: Dry slot today is impressive, resulting in mostly sunny skies...with just some increasing clouds later this afternoon into the evening. Good vertical mixing with those clear skies, helping drive some decent southwest winds and warm temperatures across the region. Expecting highs well up into the 80s across interior northern lower Michigan, with reading just a smidge cooler for areas north of the big bridge and near those big waters. That mixing will also help plummet relative humidity rather aggressively by this afternoon. Combine that with those warm temperatures and gusty southwest winds and the stage is set for elevated wildfire concerns this afternoon. Will address that issues in our hazardous weather products/graphics and fire weather products. Slug of deeper moisture arrives tonight ahead of that secondary cold front and vort max wrapping around parent upstream low pressure. Expect scattered to numerous showers to spread back overhead quickly this evening. A few embedded thunderstorms also expected. Cannot completely rule out an isolated severe storm or two given relatively steep mid level lapse rates and modest shear through the convective column. Marginally severe wind gusts and hail would be the primary concerns with any more organized updraft. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Issued at 321 AM EDT Fri May 16 2025 Pattern Synopsis/Forecast: Midlevel closed low pressure at the base of a shortwave trough will be centered over the Upper Great Lakes at the start of the long term. Chances of precipitation begin to dissipate as midlevel heights rise and push subsidence across the northwoods through Tuesday. A few scattered showers will linger across parts of Michigan through Saturday as the surface level low begins to dissipate and slowly move towards the northeast. Besides the on and off showers, biggest noticing feature will be the temperatures falling well below normal for mid May. Highs this Saturday and Sunday will remain in the upper 50s to low 60s as cold air pulls in from the north. Cloudy skies and showers will give more of a early spring or even a fall feeling, but temperatures will slowly build into the 60s and even low 70s by midweek. At the same time; troughing currently over the Pacific Northwest will work its way eastward, reaching the Great Lakes region returns chances of precip around the Wednesday/Thursday timeframe. Ensemble guidance depicts this system weakening with time and lingering across the region through the rest of the week. Light- scattered showers will continue this pattern of dreary weather to close out the forecast period. Poor organization and a lack of deep atmospheric moisture will keep rain amounts low and any risk of severe weather at a minimum. && .AVIATION /12Z TAFS THROUGH 12Z SATURDAY/... Issued at 556 AM EDT Fri May 16 2025 Any fog/mist and low clouds will quickly mix out after sunrise, leaving behind VFR conditions under mostly sunny skies today. Clouds increase and gradually lower to MVFR by later tonight as another band of showers rotate through the region. May also have a few embedded rumbles of thunder as well. Southwest to south winds become a bit gusty today, with winds decreasing again tonight. && .APX WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ SHORT TERM...MSB LONG TERM...SJC AVIATION...MSB ####018004552#### FXUS63 KUNR 160958 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 358 AM MDT Fri May 16 2025 .KEY MESSAGES... - Strong northwest winds will continue through this morning before gradually diminishing this afternoon. Gusts of 60 to 70 mph are possible across the western South Dakota plains. - Widespread frost is likely early Saturday morning across northwestern SD into portions of northeastern WY as temperatures drop into the mid-30s under light winds and clearing skies. -Unsettled pattern continues into next week with another storm system bringing appreciable rain to the region Sunday and Monday. && .DISCUSSION...(Today Through Thursday) Issued at 357 AM MDT Fri May 16 2025 06z sfc analysis shows an impressive 980 mb low centered over southeastern ND/northeastern SD. Precip has moved back southwards across much of the western SD plains north of I-90. RAP reanalysis data shows core of 50-70kt winds at 850-700 mb over western SD, these winds are mixing down to the surface. Many stations across the western SD plains are reporting gusts of 60-75 mph. The strong winds will continue through this morning into the afternoon as strong 850-700mb level winds remain overhead. Haven't made many changes to the current wind headlines aside from upgrading Tripp County to a High Wind Warning. Rain showers and high elevation snow will continue across western SD through the morning and afternoon before tapering off along with the winds as the system moves east. Colder air filters into the region late tonight with clearing skies, low level moisture, and light sfc winds supporting frost over northwestern SD into portions of northeastern WY. Have high enough confidence in widespread frost to hoist a Frost Advisory for late tonight into early Saturday morning for these areas. As the upper level low shifts to the east, quasi-zonal flow/broad upper ridging establishes itself over the Northern Plains for Saturday. Temperatures will warm slightly with highs in the 60s to 70s and mostly dry conditions for most of the region. Weak shortwave energy crosses the southern tier of the FA Saturday afternoon and evening, supporting chances for showers/storms across the Black Hills into southwestern SD. More substantial forcing moves into the region Saturday night into Sunday as an upper trof digs into the western US with modest IVT transport bringing gulf moisture into the region. TROWAL will remain over region as the sfc low shifts to the east, supporting a long duration rain event Sunday afternoon through Monday night. 00z LREF probs depict 70+% chances for the CWA to pick up >0.25" QPF from 00z Sunday to 00z Monday. There are medium-high (40-70%) probs for most of the western half of SD to pick up an inch of rain Sunday night into Monday. High elevation snow will also be possible with this system as colder air settles into the region. Shortwave ridging develops over the region by the mid-week with a chance to dry out before the next system moves into the region in the late week. && .AVIATION...(For the 06Z TAFS Through 06Z Friday Night) Issued At 1113 PM MDT Thu May 15 2025 MVFR/IFR conditions and rain will continue across northwest South Dakota. The rain will continue to push south/southeast through the overnight hours, bringing MVFR/IFR conditions back toward the Black Hills area into northeast WY, and along the I-90 corridor in South Dakota. Strong northwest winds will continue across the area through the forecast period, with gusts to 55 kt. Winds will gradually decrease after 18-19z Friday, although gusts 30-40 knots will persist into the last few hours of the forecast period. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...High Wind Warning until 6 PM MDT /7 PM CDT/ this evening for SDZ001-002-012>014-025-026-031-032-041-043-044-046-047-049- 072-073-077-078. Frost Advisory from 1 AM to 9 AM MDT Saturday for SDZ001-002-012- 013-073-078. High Wind Warning until noon MDT today for SDZ024-028. Wind Advisory until 6 PM MDT this evening for SDZ027-030-042- 074>076. WY...High Wind Warning until 6 PM MDT this evening for WYZ060. Frost Advisory from 1 AM to 9 AM MDT Saturday for WYZ056-058>060. && $$ DISCUSSION/KEY MESSAGES...Wong AVIATION...Wong