Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/23/24


Area Forecast Discussion
National Weather Service Grand Rapids MI
940 PM EDT Tue Oct 22 2024 .KEY MESSAGES... - Scattered/Isolated Showers into Wednesday - Chance of Rain Thursday Night/Friday - Dry and Seasonal Weekend Warming Towards Halloween && .UPDATE... Issued at 940 PM EDT Tue Oct 22 2024 Isolated to scattered showers and thunderstorms continue as the 500mb trough axis and vorticity max move through. A combination of mid level moisture, mid level lapse rates around 7C/km, and the 850mb jet overhead have helped to create and environment where thunderstorms have developed along the instability axis. Showers and storms will continue before tapering off by 1am. && .DISCUSSION... Issued at 215 PM EDT Tue Oct 22 2024 - Scattered/Isolated Showers into Wednesday Water vapor imagery shows the first wave tracking northeastward through northern IL. Radar shows a line of showers, associated with this wave, approaching the Chicago area. As expected the lightning has gradually decreased as the elevated instability gradually decreases. These showers will track through the CWA, likely falling apart as they do later this afternoon into the evening. However, there will still be some lift with the passing wave along with weakness in the stability/even some weak instability so it`s not 100 percent certain that we don`t see any lightning. The latest HRRR shows newer showers developing in the 01z-03z window, which would be behind the main initial batch of showers. We will hold onto the low POPs through the evening as a result of the latest model trends. A cold front pushes southeastward through the CWA late tonight into early Wednesday morning. This is looking like a dry frontal passage for most locations as the main forcing and lift stays north of the CWA. Modeled qpf is shown to be light with the northern zones having the best potential for seeing a few showers. Ensemble qpf values also support this and qpf trends are not increasing. - Chance of Rain Thursday Night/Friday A brief period of surface and upper-level ridging keeps things dry for Thursday. The primary chance of rain in the extended forecast comes Thursday Night into Friday as a weak, positively tilted, shortwave crosses over the semi-flattened ridge and drives a cold front across the CWA. This will bring a chance of showers, and even of thunder as 850mbar/750mbar LI values go negative. - Dry and Seasonal Weekend Warming Towards Halloween High pressure moves in behind the cold front, keeping the weekend dry. A thermal trough crossing the Great Lakes will keep highs in the 50s. The pattern flips by Monday as a deep trough over the western US sets up a sprawling ridge and high pressure across the eastern half of the CONUS. The return flow from this advects in significant warm air causing highs to climb back into the 70s by Tuesday, possibly continuing into the late week. Overall forecast confidence in the extended period is near average. Consistency in the overall longwave pattern is good among the ensembles, with the shift to a -PNA pattern and MJO phase 6/7 climatologically supporting next week`s warmup. However, cluster analysis does show uncertainty remains in the strength and positioning of this weekend`s trough and the following ridge. This does lend some uncertainty to the extent of precipitation and specifics of temperatures in the latter half of the extended forecast. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 812 PM EDT Tue Oct 22 2024 A cold front moving through this evening into tomorrow has brought showers with an isolated thunderstorm just north of AZO and BTL. Have VCTS through 01Z at AZO though as the sunsets chances of storms will diminish quickly. Light showers will continue overnight into tomorrow though given variability have VCSH at TAF sites. There will be a period of LLWS with frontal passage from 00Z until 08Z. Expect MVFR cigs with the potential for VFR cigs and showers could bring periods of IFR vsbys tomorrow afternoon. Conditions should improve after 00Z Thursday. && .MARINE... Issued at 215 PM EDT Tue Oct 22 2024 The observations near/in the marine zones show values occasionally reaching small craft levels. With the wind fields progged to increase slightly over the next few hours we should continue to see values reaching small craft advisory levels. There will likely be a lull in the gusty winds/higher waves at some point this evening, however with the cold front forecast to drop through region later tonight/early Wednesday the winds and waves will be on the increase again. This time though the cold air advection will give a boost to the mixing height and waves that will last through the day on Wednesday. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory until 2 AM EDT Thursday for LMZ844>849. && $$ UPDATE...RAH DISCUSSION...MJS/Thomas AVIATION...Ceru/Thomas MARINE...MJS
Area Forecast Discussion
National Weather Service Marquette MI
817 PM EDT Tue Oct 22 2024 .KEY MESSAGES... - Breezy conditions ahead of a cold front, with a quick round of light rainfall overnight. Cooler conditions on Wednesday. - Minimal gales to 35 knots are likely (50-90% chance) over mainly the east half of Lake Superior late tonight into Wednesday morning. - Another system brings a chance of light showers Thursday night and Friday with maybe some light lake effect showers behind it into Saturday along with cooler conditions. - Fire weather concerns continue into early next week with mostly dry and breezy conditions Monday-Tuesday and a trend toward unseasonably warm weather. && .SHORT TERM /THROUGH TONIGHT/... Issued at 306 PM EDT Tue Oct 22 2024 Water vapor imagery and RAP analyses show a shortwave rippling through the Lower Midwest that should continue to stay to our south, and a broader midlevel trough over the Canadian Prairies. At the surface, low pressure is centered west of James Bay, with a cold front draped SW into western MN. Southerly flow continues to strengthen this afternoon with a tightening pressure gradient ahead of the approaching cold front; gusts are already up to 20-30mph across the eastern UP, and up to 20-25mph to the west. Meanwhile, high clouds continue to stream northward into the UP, perhaps debris from the Lower Midwest wave, and this may be the culprit for our slightly cooler temperatures today (compared to yesterday). Most of the western half of the UP is peaking in the lower to mid 70s, though will not rule out some of those typically warmer, southerly downsloping spots reaching a little higher. Flow off of Lake Michigan continues to keep the eastern UP cooler, mainly in the upper 60s. Winds remain elevated into this evening as the front finally approaches closer to 00Z. This will bring a quick round of light rainfall, with ensemble guidance continuing to favor totals peaking at around 0.10-0.25in. As winds veer northwesterly and a much cooler airmass works in, expect some lake-enhancement and eventually entirely lake effect rain showers in the NW wind belts the second half of the night. Wind gusts come in at around 20-30mph behind the front. Otherwise, expect a much cooler night as temperatures fall back into the mid 30s in the interior of the western half of the UP, and the lower/mid 40s lakeside and to the east. Will not rule out some snowflakes mixing in with our rain showers, but this would be limited to the higher terrain and no accumulations are expected. && .LONG TERM /WEDNESDAY THROUGH TUESDAY/... Issued at 441 PM EDT Tue Oct 22 2024 Expect gusty northwest winds Wednesday behind tonight`s frontal passage with gusts 20-35 mph, highest over the Keweenaw. Look for highs only getting into the low to mid 40s over the west to upper 40s to lower 50s in the south central and the east. As ridging quickly builds into the region from the west Wednesday and Wednesday night, expect the lake-effect precipitation to end from west to east by late Wednesday. Min temps Wed night under mostly clear skies and light winds could be chilly, ranging from the mid 20s over the interior to the mid 30s near the Lake Superior shoreline. Sunny skies, breezy southwest winds and slightly warmer temperatures (around 60F) will occur on the backside of the departing sfc ridge on Thursday. However, another shortwave and associated sfc low moving through the Plains looks to bring cloud cover back over the U.P. late Thursday, with rain showers returning Thursday night and Friday. Again though, don`t expect much in the way of liquid precipitation amounts as most locations will be lucky to see 0.10- 0.20 inches of rainfall. A shot of cold air advection behind the shortwave could maybe bring some light lake-effect showers into mainly eastern sections Fri night into Saturday. Otherwise, expect drier conditions and a return to above normal temperatures again late weekend into early next week as high pressure builds through the Central CONUS into the Eastern Seaboard. I`m more than a bit skeptical of the higher model blend pops for WAA rain showers on Monday given the lack of a Gulf moisture connection and sprawling mid-upper level ridging across the area. Strengthening gradient ahead of the developing low pressure system over the Plains could lead to gusty southerly winds Monday into Tuesday with EPS ensemble probabilities showing a greater than 60% chance of gusts of 25 mph or higher on these days. The gusty winds combined continued warm and dry conditions could lead to elevated fire weather concerns again for early next week. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 816 PM EDT Tue Oct 22 2024 VFR conditions to persist into early tonight at all TAF sites until the onset of rain showers with an approaching cold front. Expect flight restrictions of MVFR with the frontal passage overnight and into Wednesday morning, then gradual improvement back to VFR in the wake of the front. Meanwhile, southwesterly winds have subsided for now at IWX and CMX, but it is expected to be short-lived with gusts returning overnight. At IWD and SAW, gusts will be in the 20 to 25 kt range, while CMX could gust up to 35 kt. Concurrently, winds will shift to the northwest through the night with frontal passage. && .MARINE... Issued at 441 PM EDT Tue Oct 22 2024 Expect southerly winds 20 to 25 knots over generally the eastern half of the lake into this evening, although some gusts up to 30 knots may be possible in the downslope areas along Pictured Rocks National Lakeshore and east. As a cold front drops down from Canada across Lake Superior tonight, expect winds to shift to the northwest behind the front and to increase to gales of 35 knots across much of the lake (save the far west). Gale Warnings are out for LSZ263-267 beginning 04Z Wednesday in the western zones and 06Z in the east half continuing into 15Z Wednesday. Following EPS probabilities, we have a 50-80 chance of seeing minimal northwest gales to 35 knots late Tuesday night into Wednesday over the east half. In addition to the gales, expect significant wave heights to increase to 8 to 12 feet across the lake late Tuesday night through Wednesday, with the highest waves being seen over the far eastern lake. As high pressure ridging builds in from the west Wednesday and Wednesday night, expect the winds to weaken from west to east Wednesday afternoon, becoming 20 knots or less again by midnight Wednesday night. As another low pressure system approaches from the Plains Thursday, we could see winds increase from the southwest to 20 to 25 knots and waves increase to 3 to 6 feet across the western half of the lake. Another cold front moving across the area Thursday night into Friday could bring some stronger northwest winds to 30 knots in its wake Friday into Saturday. EPS probability shows a 10-40% chance of gales to 35 kts over east portions Saturday afternoon. Winds die down briefly to 20 kts or less Saturday night as a ridge moves across the area but southerly winds will ramp back up again to 25 to 30 knots by late Sunday into early next week ahead of a low pressure developing over the Plains. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... Gale Warning from midnight tonight to 8 AM EDT Wednesday for LSZ242>244-263-264. Gale Warning from 2 AM to 11 AM EDT Wednesday for LSZ245>251- 265>267. Lake Michigan... None. && $$ SHORT TERM...LC LONG TERM...Voss AVIATION...TDUD MARINE...Voss
Area Forecast Discussion
National Weather Service Tulsa OK
848 PM CDT Tue Oct 22 2024 ...New UPDATE... .UPDATE... Issued at 848 PM CDT Tue Oct 22 2024 The current forecast for tonight remains on track with only a few minor adjustments made to better reflect the latest trends in observations. Mejia && .SHORT TERM... (Tonight thru Wednesday night) Issued at 134 PM CDT Tue Oct 22 2024 Southwest winds have actually brought higher dewpoints into the area today, keeping humidity values up from recent days. Fire weather concerns are trending lower as winds drop across NE OK, but some concern still remains over WC/NW AR. Some record highs are probably going to fall as well, with highs in the upper 80s to near 90. A PV max currently over MT will eventually carve out a pretty decent shortwave trough over the Great Lakes and mid-Mississippi Valley Wednesday. This will force a cold front, currently taking shape over the western Dakotas, south into the area. Highs will be a few degrees cooler across the north, but still toasty down south. The HREF, and to a lesser degree HRRR, show isolated showers near the front tomorrow afternoon from SE OK to WC/NW AR. HRRR model soundings don`t look impressive from an instability standpoint, so will elect to leave thunder probs below mentionable levels for now. The warm advection signal over the Ozarks with the retreating front Wednesday night into early Thursday is still there, and with the blended guidance (NBM) showing some slight chance PoPs, will go ahead and circle an area over far NE OK/NW AR after 06Z for mainly showers, though isolated thunder can`t be ruled out. Lacy && .LONG TERM... (Thursday through Tuesday) Issued at 134 PM CDT Tue Oct 22 2024 A fast-moving shortwave trough embedded within WNW flow aloft is still progged to slide across the central part of the country late Thursday into Friday. South to southwest low level flow develops ahead of the system and associated cold front Thursday, pushing highs again to near records and increasing the fire weather danger. The cold front will move in Thursday night, with models showing the best chance for showers and storms staying to our north and east over KS and MO closer to the track of the upper system. Nevertheless, will leave some low PoPs across NE OK and NW AR. Cooler weather will prevail Friday on into the weekend with low PoPs at best in or near the old front. We`re back in the warm air by Monday, and with the warm and windy conditions in place, fire weather will again be a concern. A deep trough is expected to develop over the western CONUS by early next week, that seems more certain at this point. What is not near as certain is the speed and track this trough will take across the country later in the week. Most of the clusters in the multi-model ensembles point to a slower scenario than the progressive 00Z EC and agree more with the 12Z GFS. Given low confidence, will reduce NBM PoPs next Tuesday to slight chance. If GFS is right, temps may need to be raised from current forecast as well. We`ll just have to wait and see. Lacy && .AVIATION... (00Z TAFS) Issued at 628 PM CDT Tue Oct 22 2024 Gusty southwest winds are starting to subside early this evening and will remain light overnight. A cold front will push into northeast Oklahoma after midnight, moving to near the I-40 corridor by 18Z Wednesday. Gusty northeast winds are expected across northeast Oklahoma around mid morning behind the front, continuing through the afternoon. VFR conditions are likely through the forecast period with only a few passing mid/high clouds. && .PRELIMINARY POINT TEMPS/POPS... TUL 89 59 85 61 / 0 0 10 10 FSM 90 61 91 62 / 0 0 20 10 MLC 89 63 90 64 / 0 0 20 10 BVO 91 51 82 52 / 0 0 0 10 FYV 86 57 86 55 / 0 0 20 20 BYV 84 60 84 56 / 0 0 10 20 MKO 89 60 87 62 / 0 0 20 10 MIO 87 54 81 57 / 0 0 0 20 F10 89 60 88 61 / 0 0 20 10 HHW 88 60 89 62 / 0 0 20 10 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ UPDATE...67 SHORT TERM...30 LONG TERM....30 AVIATION...12