Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/10/20

National Weather Service Albany NY
1010 PM EDT Tue Jun 9 2020 .SYNOPSIS... High pressure will build in from New Brunswick and Nova Scotia tonight, as a frontal boundary settles south of the region. The front will move north and east of the region, as a warm front tomorrow bringing some showers and thunderstorms. A warmer and more humid air mass will be over the region Wednesday night into Thursday, as a cold front will bring more showers and thunderstorms with locally heavy rainfall. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Wind shift boundary has drifted south through KGFL, K5B2 and KVSF, and likely KPSF. The wind shift boundary will continue to drift south and west and winds will become northeast to southeast light and steady at less than 6 Kt, occasionally calm tonight. Only some mid and high clouds from time to time through the night as low level dewpoints hold steady or slowly rise. Just some minor adjustments to sky cover, timing of weak wind shift and temperatures through the night. Previous AFD has a few more details and is below... Some mid and high clouds will be around tonight, and it will be variable cloudy. The winds will go briefly light to calm allowing some radiational cooling, but shortly before or after midnight. However, the low-level east to southeast flow will increase. Some stratus may form and move into locations south and east of Albany shortly before sunrise. Depending on the winds and degree of cloud cover. Lows will be in the upper 50s to lower 60s from the Capital Region and Mohawk Valley south and east, as lower to upper 50s are possible to the north and east. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... Tomorrow, the guidance has trended cooler with temperatures tomorrow, as initially clouds and a less humid air mass will be over the region. The frontal boundary will lift northward as a warm front in the morning. The low-level convergence increases and some showers and initially isolated/scattered thunderstorms will break out in the late morning/early pm north and west of the Capital Region. A limiting factor will be the amount of instability available. The greatest mean MUCAPES on the latest 12Z HREFS are west of the Hudson River Valley in the 750-1250 J/kg range. The 0-6 km shear bulk shear is 30-40 kts. Less instability is available from the Hudson River Valley east. The gradient in SBCAPE on the NAM/GFS sets up along the western periphery of the forecast area along the western Mohawk Valley/western Adirondacks/eastern Catskills with 1000-1500 J/kg with slightly higher amounts as dewpts rise into the 60s. We leaned close to the 3-km NAMnest and HRRR with some convection forming west and northwest of the Capital Region, especially in the afternoon. The mid-level lapse rates look weak at less than 6C/km. PWATS will be on the rise into the 1.5-2.0" range late in the day. A few multicells or an isolated supercell may be possible, as we break into the warm sector in the "Slight Risk" region in SPC Day 2 outlook. Damaging winds and large hail would be in the main threat for the southern Adirondacks, western Mohawk Valley, Schoharie Valley and eastern Catskills. The 0-3 km SRH values are high initially in the 200-350 (m/s)2 range due to the strong veering in the low-levels. A isolated tornado may be possible in the western Mohawk Valley into the southern Adirondacks. We added small hail, gusty winds and locally heavy rainfall for areas in the Slight Risk area. We were not confident further east. Max temps were kept in the lower to mid 80s range in the valley, and upper 60s to 70s over the higher terrain and across the northern Berkshires into southern VT. Wednesday night...The convection should begin to diminish with the loss of the diurnal heating and less instability. Any severe threat should decrease before 9 pm. A prefrontal trough ahead of the cold front may keep the scattered showers going in bands. The air mass becomes very humid with sfc dewpts rising into the 60s to close to 70F. The PWATS will be in the 1.7-2.0+" range. These values are +2 to +4 STDEVs above normal based on the latest 12Z GEFS. We kept PoPs in the likely and high chance range. We also kept a slight chance of thunderstorms with 12Z mean MUCAPEs on the latest HREFS in the 250-500 J/kg range. It will be muggy with lows in the lower to mid 60s over the higher terrain, and upper 60s to lower 70s in the valleys. Thursday...The latest Ensemble guidance and some of the CAMS show the front make steady progress across the forecast area during the late morning into the afternoon. The low-level convergence with the front will focus bands of showers and some thunderstorms. Any strong thunderstorms would be over the southeast extreme of the forecast area. Sfc heating may be limited due to lots of clouds. The 12Z GFS continues to be faster with the cold frontal passage compared to the latest NAM/ECMWF. We will continue to monitor for locally heavy rainfall. Highs will be mainly in the 70s to lower 80s. Cooler and drier air may get into the southern Adirondacks quickest with highs only in the upper 60s to lower 70s. Thu night...Showers over western New England will end early. Cold advection occurs in the wake of the front. The skies may become mostly clear to partly cloud. It will become less humid with dewpoints falling into the 50s and even mid and upper 40s over the southern Adirondacks. Lows temps will be mainly in the 50s, though a few lower 60s are possible in the Capital District, mid Hudson Valley and NW CT. && .LONG TERM /FRIDAY THROUGH TUESDAY/... There remains considerable uncertainty regarding the long term period and how the upper level patterns evolves during the weekend into early next week. It appears that there will be an upper level trough approaching the Northeast and it may become cutoff. However, it is unclear when/where the cutoff occurs and exactly how it tracks. The latest 12z ECMWF has the system cutting off and remaining further west than the 12z GFS. The 12z GGEM is more similar to the GFS, although slightly further west. As a result, there will be a threat for some showers during the long term period, especially for the Monday through Wednesday time period. The coverage and amounts of precipitation will depend on how the upper level pattern evolves, so this is still very unclear. For now, have gone with slight to low chance POPs through much of the extended period, with the highest POPs during the upcoming week. Best chance will likely be during the diurnally favored afternoon and evening hours. For now, will not include any thunder, but this is something that could be included in later forecasts once the pattern becomes more clear. Will keep temps fairly close to seasonal normals, with valley highs in the mid 70s to low 80s. Overnight lows will generally be in the 50s. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... Weak wind shift boundary is drifting south through the night but just some intervals of mid level clouds tonight. Intervals of clouds through Wednesday with just some scattered showers and isolated thunderstorms Wednesday afternoon. Southwest to northwest winds at less than 10 Kt will shift to northeast to southeast at less than 6 Kt this evening but variable at KPOU. The variable to light northeast to southeast winds will continue through the night. Winds become relatively uniform southeast everywhere by about 14Z at 10 Kt or less but could gust to around 15 Kt at KALB Wednesday afternoon. Outlook... Wednesday Night: High Operational Impact. Breezy. Likely SHRA...TSRA. Thursday: High Operational Impact. Breezy. Likely SHRA...TSRA. Thursday Night: Low Operational Impact. NO SIG WX. Friday: No Operational Impact. NO SIG WX. Friday Night: No Operational Impact. NO SIG WX. Saturday: Low Operational Impact. Slight Chance of SHRA. && .FIRE WEATHER... High pressure will build in from New Brunswick and Nova Scotia tonight, as a frontal boundary settles south of the region. The front will move north and east of the region, as a warm front tomorrow bringing some showers and thunderstorms. A warmer and more humid air mass will be over the region Wednesday night into Thursday, as a cold front will bring more showers and thunderstorms. RH values will increase to 809 to 100 percent Wednesday morning, and lower to 50 to 70 percent during the afternoon. Relative humidity values will rise to 90 to 100 percent Thursday morning. The winds will increase from the northeast to southeast at less than 10 mph tonight. They will be from the south to southeast at 5 to 15 mph tomorrow and will be southerly at 5 to 15 mph Wednesday night. && .HYDROLOGY... No widespread problems are expected on the main stem rivers the next several days in the ALY Hydro Service Area /HSA/. Mainly dry weather will continue this afternoon into Wednesday morning for the ALY HSA. A warm front will increase the threat of showers and thunderstorms Wednesday afternoon into Wednesday night. A cold front will bring additional showers and thunderstorms on Thursday. Total rainfall may range from a third of an inch to three quarters of an inch. Some locally higher amounts in excess of an inch are possible, especially from any convection, as PWAT values rise into the 1.5-2.0" range, which are 2 to 4 standard deviations above normal. Gridded FFG values are high at the moment due to dry soil antecedent conditions over much of the HSA. Some rainfall rates may be briefly intense with any thunderstorms Wednesday into Thursday. A brief period of dry weather is possible Thursday night into early Friday in the wake of a cold front. A closed or cutoff low may increase the threat for showers again on the weekend into early next week, however, confidence is rather low on weather impacts at this time due to a lot of uncertainty with the formation and location of the cut-off and its associated precipitation. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...Wasula NEAR TERM...NAS/Wasula SHORT TERM...Wasula LONG TERM...Frugis AVIATION...NAS FIRE WEATHER...Wasula HYDROLOGY...BGM/Wasula
Area Forecast Discussion
National Weather Service Bismarck ND
842 PM CDT Tue Jun 9 2020 .UPDATE... Issued at 840 PM CDT Tue Jun 9 2020 The forecast generally looks to be in good shape. Thunder has all but ended over the area and showers will continue to slowly diminish as the sun sets. For this update, just tweaked cloud cover based using the latest iteration of the NBM which seems to be doing very well with the current cloud trends. UPDATE Issued at 607 PM CDT Tue Jun 9 2020 Widespread showers with a few weak thunderstorms have developed as expected across much of western North Dakota late this afternoon as we remain in cyclonic flow aloft. An area of steadier rain associated with a vacating shortwave continues to lift northeast through the James River Valley. For this update, tweaked precipitation chances to better reflect the latest radar observations and trends along with a time lagged RAP solution that seems to have a good handle on what`s going on. Otherwise, just blended in the latest observations to the forecast. && .SHORT TERM...(This evening through Wednesday) Issued at 246 PM CDT Tue Jun 9 2020 Showers east and scattered showers and possibly isolated thunderstorms are in the forecast for this evening. Showers and possibly isolated thunderstorms are in the forecast tomorrow as well for the northern and central portions of the state. Severe weather is not expected. The synoptic picture this afternoon centered around broad cyclonic flow over the central CONUS with two shortwave troughs ejecting over the Rockies and High Plains as well as mid-level circulation from Tropical Depression Cristobal becomes embedded in the mean cyclonic flow over Iowa/Illinois. The two western shortwaves, one over the Montana/North Dakota border with the southern over western Kansas will continue to eject embedded impulses over the eastern Dakotas this evening with widespread showers expected until both low pressure centers move east after midnight. Showers and possibly thunderstorms are expected to develop this afternoon/evening in western North Dakota as cold air aloft accompanies the mid-level trough. With just weak instability, severe weather is not expected. Tonight and tomorrow, the mid-level circulation remains in place over North Dakota and southern Saskatchewan/Manitoba as a secondary shortwave arrives. With steep mid-level lapse rates and broad cyclonic flow aloft, diurnally driven showers and possibly thunderstorms should develop across the north and much of the central portions of the state tomorrow afternoon and evening. MUCAPE should be low enough to preclude strong thunderstorms. Temperatures tonight and tomorrow will remain on the relatively cooler side with lows in the 40s tonight and highs in the low 70s on Wednesday. Persistent mid-level impulses overnight should keep enough of a pressure gradient to prevent overall temperatures from dropping below 40. With the northwest flow pattern and steep low level lapse rates, we bumped up winds tomorrow to the sustained 15 to near 25 mph range. .LONG TERM...(Wednesday night through Tuesday) Issued at 246 PM CDT Tue Jun 9 2020 A dry and warming trend is in the forecast through the rest of the week before convection chances return Saturday night. Through the latter half of the week, northwest flow over the Northern Plains continues as a ridge begins to build over the Rockies and a deep trough develops over the southwest coast. Guidance shows low-mid level warm air advection beginning on Thursday, which should allow for a gradual warming and dry trend as the western ridge moves over the Northern Plains through Saturday. Highs in the upper 70s and 80s are expected by Friday/Saturday. Deterministic and ensemble guidance is in relatively good agreement in the ridge moving off to the east over the weekend with more active flow taking over, allowing for thunderstorm chances to possibly return Saturday night. With the deep trough developing to our west on Saturday, a strong pressure gradient should develop southerly winds within the associated lee surface cyclone. NAEFS guidance shows 850mb winds within the 90th climatological percentile Saturday afternoon with 850mb winds near or around 40 kts forecast. We`re far enough out in the forecast period to hold back from more specific messaging in products like the HWO, but with this kind of setup wind advisory criteria winds are not out of the question. Looking into early next week, CIPS ensemble guidance shows a mean troughing pattern over the Pacific Northwest with possibly active flow over the Northern Plains. Climatologically this would indicate the possibility for severe storm chances to continue through next week. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 607 PM CDT Tue Jun 9 2020 Scattered showers will continue through the early evening hours before diminishing overnight. These pop up type showers will be very hit and miss and will not last long, so will only keep the mention of VCSH in the forecast. While there is a chance for an isolated lightning strike or two, any embedded thunderstorms will be very few and far between. Clearing will then take place overnight and a breezy day will setup across east Wednesday afternoon. VFR conditions are expected through the period. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ZH SHORT TERM...AE LONG TERM...AE AVIATION...ZH
Area Forecast Discussion
National Weather Service North Platte NE
637 PM CDT Tue Jun 9 2020 .SHORT TERM...(This evening through Wednesday night) Issued at 320 PM CDT Tue Jun 9 2020 The high wind warning can be cancelled west of Lincoln county. H850mb winds have subsided to 50 kts or less near and west of Ogallala according to the RAP model. Elsewhere, the warning will continue until 9 pm as planned. The NAM and RAP soundings show mixing heights falling off very quickly with the loss of daytime heating. The warning might need an extension in time and an expansion north into ncntl Nebraska if the HRRR model gusts verify. The rain should limit mixing heights and lessen the gust potential. There is evidence of this happening Ogallala and Imperial where gusts have fallen off. Pacific high pressure across the Cntl Rockies will build east overnight and skies should clear from west to east by Wednesday morning. The guidance blend plus bias correction was the basis for lows in the 40s overnight. The high pressure will present clear skies Wednesday and Wednesday night. The blend suggested highs in the 70s and lows in the 40s to lower 50s. .LONG TERM...(Thursday through Tuesday) Issued at 320 PM CDT Tue Jun 9 2020 Northwest flow aloft will continue aloft through Friday and then transition to southwest as another upper low drops into the Pacific northwest. A trof of low heights will extend south through the Desert Southwest and this should flush warm air across the Rockies. Temperatures at h850mb will rise back to around 25C and 13C at h700mb. Temperatures around 90F are in place Sunday through Tuesday. Diurnal heating might be sufficient for isolated thunderstorm development across wrn Nebraska over the weekend. These storms would likely originate off the Laramie Range as the upper level forcing is very weak. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 636 PM CDT Tue Jun 9 2020 An upper level low pressure system will move east with showers ending from west to east soon after 06Z. Strong northwest winds have begun to subside, but gusts above 30KT will remain possible this evening. VFR conditions are also expected, with skies becoming SCT250 around 06Z. Mainly SKC on Wednesday, with winds near 31015G22KT during the day. && .HYDROLOGY... Issued at 320 PM CDT Tue Jun 9 2020 The MBRFC ran their forecast model for the Elkhorn river this morning and concluded the river will rise to around 10.0 feet by Saturday. This is moderate flood stage. The 4 to 6 inch stripe of rainfall extending from near North Platte to Stapleton, Brewster and Stewart has produced rises on the river gages across the Sandhills but just the Elkhorn river appears to be flooding. The Flood Watch will continue across ncntl Nebraska. One round of elevated thunderstorms is underway and producing a quick 1/4 inch of rain with the stronger thunderstorms. The HRRR suggests a second burst of scattered thunderstorms forming further west late this afternoon affecting Custer county and areas north. Satellite suggests ncntl Nebraska will remain under an h700mb warm air advection zone this evening. The HRRR suggests another 1/2 to locally 3/4 of an inch of rainfall this afternoon and early this evening. && .LBF WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 9 PM CDT /8 PM MDT/ this evening for NEZ036>038-058-059-069>071. Flood Watch until 7 PM CDT this evening for NEZ006>010-026>028- 038. && $$ SHORT TERM...CDC LONG TERM...CDC AVIATION...Roberg HYDROLOGY...CDC
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
557 PM CDT Tue Jun 9 2020 .SHORT TERM... (Through Late Wednesday Night) Issued at 234 PM CDT Tue Jun 9 2020 Widespread rainfall associated with the remnants of Cristobal has largely moved out of the far northern sections of the forecast area with the surface low now currently near Burlington, IA. Behind this system, the focus is on the possibility of convective initiation along a warm front extending eastward from a separate surface low located over east-central Kansas. Believe the 1500 UTC experimental HRRR has the best handle on how things are likely to evolve through this evening. It suggests isolated-scattered showers and thunderstorms developing very late this afternoon in vicinity of the warm front moving north through the late evening before exiting the CWA. The combination of capping and mid/upper level subsidence in the wake of Cristobal makes initiation at all not a sure thing, but the best chances likely will be across portions of northeast Missouri by mid evening where low-level convergence and some cooling aloft occurs downstream of the approaching trough. The atmosphere however is certainly supportive of strong to severe thunderstorms given strong instability and deep-layer shear, including supercells. Damaging winds and isolated tornadoes remain the main threats with any organized convection that does develop, mainly between 7-10PM this evening for portions of northeast Missouri. After the warm front and any associated convection moves north of the CWA before midnight, mostly dry weather is forecast for the remainder of the night. The exception could be some isolated showers or storms along the eastward moving dryline, mainly along/east of the Mississippi River. Isolated-scattered showers are possible once again on Wednesday along/ahead of the trailing cold front attendant form a deepening surface low across the Upper Midwest. The main story however for Wednesday will be the much cooler and less humid conditions. High temperatures will likely struggle to hit 70 degrees west of the Mississippi River with lower stratus and strong low-level cold air advection. For areas further east, mid to upper 70s are favored. A broken to overcast cloud deck and gusty west/southwest winds will likely make it feel even chillier across the bi-state area, more analogous to early May than mid June. Decreasing cloudiness along with relaxing west/northwest winds are likely Wednesday night as the pressure gradient relaxes south of the exiting surface low. A seasonably cool and dry night should be in store with lows in the 50s areawide. Gosselin .LONG TERM... (Thursday through Next Tuesday) Issued at 234 PM CDT Tue Jun 9 2020 Largely dry weather with near to slightly below normal temperatures is favored for the remainder of the 7-day forecast. The GEFS/EPS show a strong shortwave trough transversing the Great Lakes late Friday into Saturday, which slowly propagates eastward heading into early next week. This feature is expected to send a backdoor cold front through most of the CWA early this weekend, but moisture return and forcing for ascent is nearly non-existent, so dry weather is expected to continue. Temperatures ahead of the front should be right near normal Thursday/Friday with highs in the low to mid 80s. Behind the front, temperatures should cool about 5 degrees. For this weekend, highs are likely to be in the upper 70s to low 80s with lows in the 50s once again. The dry weather is likely to continue through next Tuesday as ensemble guidance shows the mid/upper level ridge axis edging eastward toward the mid-Mississippi Valley. The main change will be a likely moderation in temperatures as 850-hPa temperatures climb toward +20C. Highs on Tuesday are likely to climb back above normal as readings are expected to reach the mid to upper 80s. Gosselin && .AVIATION... (For the 00z TAFs through 00z Wednesday Evening) Issued at 537 PM CDT Tue Jun 9 2020 The MVFR cloudiness should scatter out early this evening in UIN as the remnants of Cristobal move further northeast of this region. Widely scattered showers and storms are expected this evening as a warm front lifts northeastward through the area early this evening, while a dry line extending from a surface low over northeastern KS southeast through southwestern MO moves eastward through the taf sites later this evening. The diurnal cumulus field should dissipate later this evening due to the loss of daytime heating, and as drier air filters eastward into the region. MVFR cloudiness will advect into the taf sites Wednesday morning along a cold front moving eastward through our area. Gusty southwest winds will weaken this evening, then veer around to a west-northwest direction Wednesday afternoon as they strengthen after fropa. SPECIFICS FOR KSTL: Widely scattered showers and storms are expected this evening as a warm front lifts northeastward through the area early this evening, while a dry line extending from a surface low over northeastern KS southeast through southwestern MO moves eastward through STL late this evening. The diurnal cumulus field should dissipate later this evening due to the loss of daytime heating, and as drier air filters eastward into the region. MVFR cloudiness will advect into STL by late Wednesday morning along a cold front moving eastward through our area. Gusty southwest winds will weaken this evening, then veer around to a west-northwest direction Wednesday afternoon as they strengthen after fropa. GKS && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...Wind Advisory until 7 PM CDT this evening for Bond IL-Clinton IL- Fayette IL-Marion IL-Montgomery IL-Washington IL. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Marquette MI
802 PM EDT Tue Jun 9 2020 .SHORT TERM...(This evening through Wednesday) Issued at 442 PM EDT TUE JUN 9 2020 WV imagery and RAP analysis indicated a mid/upper level ridge from the southeast CONUS into the Great Lakes and troughing through the western Plains. The circulation center with the remnants of TS Cristobal was located near the southeast corner of IA with a broad shield of moderate to heavy rain from eastern IA and nrn IL into se MN. Another strong upstream shrtwv or mid level low was located over wrn KS. Otherwise, even with increasing high clouds, temps have climbed into the upper 80s over much of Upper Michigan, except near the Great Lakes with lake breezes have kept readings in the upper 60s to 70s. Tonight, expect the Cristobal low to continue lifting northward with a path through central Upper Michigan by 12z/Wed bringing a period of heavy rain to most of the area. Expect the heaviest band of rain on the west side of the low track in the area of strongest isentropic lift. Tropical moisture with PWAT values above 2.0 inches will favor very efficient rain production during the brief period stronger dynamics. The models have trended slightly eastward with the axis of highest QPF compared to earlier runs with amounts that are also not quite as high. The higher amounts in the 1-2 inch range are still expected through the west. However, there is still some uncertainty with how well the models will depict the higher QPF potential and where the heaviest amounts will occur as some locally higher amounts to 3 inches may be possible in a narrow area. A Flash Flood Watch was posted over the west where the heaviest rain is expected. Otherwise, QPF in the 0.75 to 1.25 inch range is expected over much of the rest of the area. Wednesday, a period of strong southerly winds is also expected late tonight through Wed morning as the low moves through given the large pres rise/fall couplet ahead of the low. Although stability may be less than favorable for deeper mixing, 3 hour pres falls of 10 mb ahead of rises to 6 mb will support a vigorous isallobaric component so that gusts into the 40-50 mph range will be likely, mainly over the east from Schoolcraft into Luce counties. The strong winds will also likely cause some lakeshore flooding on the north end of the bay of Green Bay and along Lake Michigan to the east. After the low lifts north of the area, expect a lull in the pcpn with gusty west winds. Rain with the Plains shrtwv lifting toward the area will increase from the southwest in the mid to late afternoon. .LONG TERM...(Wednesday night through Tuesday) Issued at 500 PM EDT TUE JUN 9 2020 An amplified pattern is expected over N America thru at least early next week. Trof currently shifting toward the Plains will move across the western Great Lakes late Wed thru Fri. Over the weekend, pattern will again become quite amplified with a fairly deep trof moving into the western U.S. forcing an amplified central N America ridge while the Great Lakes trof shifts toward the eastern U.S. Pattern will then begin to deamplify next week, but upstream ridge may end up settling over the Upper Great Lakes for at least a couple of days before shortwaves moving across Canada begin working to suppress it. For Upper MI, these changes in the large scale pattern will result in the current well above normal temps (hot conditions over western Upper MI) trending much cooler, probably well blo normal for at least one day, during the last half of this week as the trof to the w moves across the Great Lakes region and toward the eastern U.S. Warmth will then return early next week as the upstream ridge moves to the Great Lakes. As for pcpn, there will be 2 main pcpn events over the next 7 days. The first occurs tonight into early Wed morning as TD Cristobal and its associated tropical moisture race n across the area, resulting in a quick mdt to hvy rainfall for the fcst area. Shortwave in the base of the approaching mid-level trof will then swing negative tilt thru the Upper Lakes, bringing another round of mdt to potentially locally hvy rainfall across the fcst area later Wed aftn/night. Then, under the cooler conditions and cyclonic flow, sct -shra may occur Thu, possibly lingering into Fri. The weekend will be dry with Canadian sfc high pres ridging s into the Great Lakes downstream of the amplified central N America mid-level ridge. There may be a risk of shra/tsra at some point early next week if the Great Lakes ridge begins to deamplify, allowing shortwaves to move closer to the northern Great Lakes as the westerlies settle s toward the area. Some recent trends in longer range guidance suggest this deamplification may be delayed, allowing dry weather to continue thru early next week. Beginning Wed night...attention will be on shortwave currently in the base of the approaching mid-level trof as it swings negative tilt into the Great Lakes. Strong deep layer forcing and upper diffluence are noted with this feature as it moves into the northern Great Lakes. ECMWF has been most consistent on this feature generating another area of mdt to potentially hvy rainfall across the fcst area, but it has also shown a gradual eastward trend over the last several runs. 12z run points toward central and eastern Upper MI to be impacted by the heavier rainfall. Other models are coming inline with this idea, though the cams tend to favor central Upper MI for heaviest pcpn. GFS is centered more in eastern Upper MI. In any event, with the heaviest rainfall tonight over western Upper MI, it will be beneficial to have the heaviest rainfall with this next round of shra occurring e of that area. Fcst will reflect highest pops/qpf over the central and eastern fcst area with pcpn diminishing and mostly ending from w to e overnight. Expect 0.5 to 1 inch of pcpn, but potential is there for locally 1.5-2 inches. Winds should become breezy under caa regime and fairly tight pres gradient. With the mid-level trof over the area on Thu, models show a shortwave tracking se into the northern Great Lakes. Should see isold to sct -shra activity with this feature, with greater coverage in the aftn and across the s half of Upper MI as daytime heating adds a little instability. NAM was discounted as it was an outlier showing a cold rain developing across the northern and eastern fcst area due to a much sharper shortwave trof swinging across the northern Great Lakes. Will likely become a windy day as 40+kt of wind will be able to be tapped as mixed layer builds. Winds should be strongest over the Keweenaw under favorable wnw wind direction. Wind advy will probably be needed there, potentially high end advy. Cool, Canadian sfc high pres will begin to build sse into the Upper Great Lakes on Fri. The high will then be firmly in control for the weekend. Not out of the question that there could be a few sprinkles or isold -shra on Fri as fcst area will still be within the western part of the mid-level trof. Fri will be the coolest day as 850mb temps will be down around 0C. Will be especially cool along Lake Superior, especially e of Marquette where lakeside locations will not get out of the 40s. In the interior, highs will range up thru the 50s and lower 60s. The weekend will be dry with temps moderating, back close to normal for Sun. There may be a frost risk in the interior Fri night and/or Sat night. Warming will continue Mon/Tue, and at this point, there is no solid signal for any pcpn. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 800 PM EDT TUE JUN 9 2020 VFR conditions are expected to give way to MVFR and IFR conditions tonight as the remnants of TS Cristobal will move into Upper Michigan, bringing heavy rain and gusty winds. However, with the low passing through central Upper Michigan, confidence in the wind direction and speed is lower as the low moves through, especially at KSAW, where LLWS is expected overnight. LLWS is also expected at KIWD and KCMX, though it should not last as long at these TAF sites. The IFR conditions will improve Wed morning as the low moves away and westerly winds increase. KCMX should have the highest gusts Wed. However, depending on how fast the low behind Cristobal moves into the area, conditions could worsen yet again at the end of the TAF period. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 536 PM EDT TUE JUN 9 2020 Challenging forecast coming up over the next couple of days. Remnant low pres from what was once tropical storm Cristobal will quickly lift nne, passing near Marquette Wed morning around 12z and then exiting nne of Lake Superior by early aftn. Wind fcst is complicated by a very stable temp profile over Lake Superior which will limit mix down of much stronger winds not far above the lake sfc. On the other hand, tight pres gradient and notable pres rise/fall couplet associated with the quick moving system supports enhanced winds. Strongest winds will mostly occur along and e of the low pres track, and in particular at high obs platforms. For now, expect e to se gales of 35-40kt to develop over eastern Lake Superior overnight. As the low moves out across Lake Superior Wed morning, strong pres rise/fall couplet will be aligned to favor a brief period of potentially stronger winds over far eastern Lake Superior. Not out of the question that gusts could exceed 45kt for a couple of hrs. On the s side of the exiting low, a period of westerly gales of 35-40kt is possible. Winds will settle back to 20-30kt during the aftn. Over the western part of Lake Superior, winds will generally be under 25kt tonight/Wed. As a secondary low pres lifts ne of the Great Lakes Wed night, colder air and a tight pres gradient should support 35-40kt wnw gales developing over the e half of Lake Superior late Wed night into Thu morning. Winds will then diminish, falling blo 20kt for Fri, as high pres begins to ridge sse into the Upper Great Lakes. Light winds mostly under 15kt should prevail over the weekend. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Lakeshore Flood Advisory from 5 AM to 2 PM EDT Wednesday for MIZ013-014. Wind Advisory from 4 AM to 11 AM EDT Wednesday for MIZ007-014- 085. Flash Flood Watch through Wednesday morning for MIZ002-009-084. Lake Superior... Gale Warning from 2 AM to 2 PM EDT Wednesday for LSZ251-266-267. Lake Michigan... Gale Warning from midnight tonight to 10 AM EDT Wednesday for LMZ221-248-250. && $$ SHORT TERM...JLB LONG TERM...Rolfson AVIATION...TAP MARINE...Rolfson