h1. toledo weather mon jun 22 2015 spc ac 220558 day 1 convective outlook nws storm prediction center norman ok 1258 am cdt mon jun 22 2015 valid 221200z - 231200z ...there is an enh risk of svr tstms from the mid-upper ms valley ewd into lower mich... ...there is a slgt risk of svr tstms over a large portion of the midwest and great lakes... ...there is a mrgl risk of svr tstms from ern ks into the northeastern u.s.... ...there is a mrgl risk of svr tstms over nrn parts of fl into the wrn carolinas... ...summary... scattered severe storms are likely across parts of the upper mississippi valley and great lakes regions...some of which should be intense...mainly from midday through the evening on monday. the threat for large to very large hail and a strong tornado appear to be greatest over southern wisconsin and northern illinois. ...upper ms valley/great lakes... considerable uncertainty remains regarding the forecast evolution of a severe mcs across the nrn plains into the upper ms valley prior to the start of the period. as a result...confidence for this severe forecast is tempered owing to several potentially critical variables 1) longevity/severity of early morning mcs from the ms valley into the great lakes 2) preferred storm mode /supercell and/or bow echo/. given relatively high uncertainty...will defer substantial changes to the next outlook. the primary shortwave trough will move from the nrn plains to lake superior during the day while a potential convectively-generated mcv evolves from squall line activity leading into the day 1 period. in the low levels...a reservoir of rich moisture over the lower to mid mo valley will advect n/newd into the mid ms valley/wrn great lakes during the morning owing partially to strong low-level waa. while it is possible for the early morning storms to continue ewd from the mid-upper ms valley into the cntrl great lakes...lessening buoyancy with ewd extent should serve to weaken this activity. a strong influx of low-level moisture /characterized by 16-18 g per kg lowest 100 mb mean mixing ratios/ will likely move into nrn il/wi vicinity along and to the s of trailing outflow and ahead of the approaching cold front. it is probable storm redevelopment /sctd coverage/ will occur later in the afternoon near the residual boundary over the wrn great lakes or along the front located over cntrl wi sw into ern ia. the strength of the deep layer shear vector /50-70 kt/ and its orientation to the boundary coupled with a very strong to extremely buoyant /3000-4500 j per kg mlcape/ boundary layer would promote explosive updraft development and a supercellular mode early in the storm lifecycle. all severe hazards would be possible with this activity...including significant hail/wind/tornado. further storm development along the front will favor a transition to a mixed mode and probably yield a wind/hail threat becoming predominate with time. storms should move downstream and into the srn and lower great lakes states overnight with the primary risk being isold large hail/wind. ...parts of the sern u.s... a flattened mid-level anticyclone will persist off the se u.s. and diurnally-driven storms will likely develop during the afternoon. a very weak wind profile will result in slow-moving pulse storms which will likely propagate on convective outflow. steepened low-level lapse rates owing to strong diabatic heating coupled with pw 1.75-2.0 inches will promote water loading with the more intense cores. wet microbursts capable of pockets of wind damage will be the primary threat and this activity will diminish during the early evening. ..smith/rogers.. 06/22/2015 click to get wuus01 ptsdy1 product note: the next day 1 outlook is scheduled by 1300z hr. According to the 1:58 a.m. SPC update, the main threat for severe weather remains to the north and west of Toledo. And it seems that some aspects for severe weather have decreased for Michigan. The main risk for tornadoes and large hail exists over southern WI, northern IL, and eastern IA. But it appears that the NWS won't know for sure until mid-day. Excerpts from the 1:58 a.m., Mon, Jun 22 Day 1 Convective Outlook: q. ...upper ms valley/great lakes... *considerable uncertainty remains* regarding the forecast evolution of a severe mcs across the nrn plains into the upper ms valley prior to the start of the period. as a result... confidence for this severe forecast is tempered owing to several potentially critical variables 1) longevity/severity of early morning mcs from the ms valley into the great lakes 2) preferred storm mode /supercell and/or bow echo/. given relatively high uncertainty... *will defer substantial changes to the next outlook.* the next day 1 outlook is scheduled by 1300z [9:00 a.m. EDT] q.. br. !https://farm4.staticflickr.com/3767/18425440393_eb989ee46a_z.jpg! br. Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point. !https://farm1.staticflickr.com/400/18425440373_97340c7579_z.jpg! br. Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% or greater probability of wind gusts 65 knots or greater within 25 miles of a point. !https://farm1.staticflickr.com/412/18425440343_be6e8f1ffc_z.jpg! br. Probability of one inch diameter hail or larger within 25 miles of a point. Hatched Area: 10% or greater probability of two inch diameter hail or larger within 25 miles of a point. !https://farm1.staticflickr.com/327/18425440283_1530f8ec90_z.jpg! hr. fxus63 kdtx 220635 afddtx area forecast discussion national weather service detroit/pontiac mi 235 am edt mon jun 22 2015 short term...today and tonight today (through approximately 02z) an mcs is maturing over south dakota at press time in response to the previously discussed strong dynamic response across the northern united states and subsequent low-level jet response. surface pressure falls in the lee of the rockies are forecast to consolidate into a low pressure center over minnesota early this morning with the attendant instability axis along the arcing warm front providing a focus for continued mcs propagation. classic conceptual model suggests the mcs will enter the decaying stage upon weakening of the nocturnal jet and as it outruns synoptic scale forcing during the morning. however, the present situation suggests pause given strong dynamic response accompanying a rapid synoptic scale evolution. high resolution models place the mcs on the expected ese trajectory over southern wisconsin by late this morning. low-level jet will only strengthen through the morning into this afternoon as the warm front lifts north. extrapolation puts perhaps the northern fringes of the mcs over south-central lower michigan by mid-afternoon, where the surface instability axis will already be firmly in place. any organized severe wind threat would likely only clip southwestern counties 20-00z. more likely scenario for this afternoon will be the potential for lead discrete development along the warm front in advance of mcs/remnants, possibly along mcs outflow propagating into the warm sector environment. updrafts along the warm front itself may initially struggle to organize and root in the boundary layer given unfavorable position along the periphery of the more favorable warm sector environment. better chance for a severe threat may come in response to updraft development along outflow or simply a result of ongoing theta-e advection within the warm sector. despite being shrouded in convective debris for the bulk of the day, advective processes will ensure mlcape ramps up to 2000-3000 j/kg 19-00z, during which time hodographs will become increasingly large and formidable with any post-warm front development likely becoming severe. the initial threat before sundown will be large hail to golf ball size and winds to 60 mph. lcls upwards of 3kft not particularly supportive of tornado development during this period. coverage may be increased toward the saginaw valley where mcv within corridor of greatest synoptic scale height falls, and immediately downstream of the surface low will provide stronger forced ascent. defined lull in activity is a reasonable expectation during mid evening hours probable given mcs passage and resultant mid-level latent heat bubble/stabilization and wake subsidence. concern that this stable period will short circuit cold front convection later in the night exists, but is minimal at this time given very strong advective processes and fast evolution of features on the synoptic scale. tonight (approx 02-12z) aforementioned potential mcs disruption not withstanding, severe threat will fully mature during the late evening as 50kt swly llj and 70kt 500mb wind max become juxtaposed with extremely buoyant environment immediately in advance of the surface cold front. incredible 0-6km bulk shear of 60 to 65 knots oriented favorably to the initiating boundary, combined with lack of strong linear forcing, and mlcape of 2000 j/kg or higher will favor an initial mode of supercells over central lower michigan into the saginaw valley and locations north of m59. 0-1km/0-3km srh of 250/330 m2s2 respectively suggest very strong mesocyclone rotation capable of producing hail to golf balls or higher, though elevated freezing levels warrant remaining conservative with regard to hail potential. in addition, a legitimate tornadic threat would also exist during the supercell phase as lcls lower with the help of advection of rich low-level moisture and decreased mixing during the nocturnal period. incredibly high vgp around 1 is a testament to the magnitude of shear available for tilting while sufficient cape in the lowest levels looks to be available to enhance stretching processes. a few tornados cannot be ruled out mainly north of m59. magnitude of environmental wind field alone will also support straight line wind gust potential to 70 mph. passage of the upper wave will result in rapid veering of the wind profile over southeast michigan after about 05z leading to increasingly straight hodographs as convection shifts toward the southern half of the cwa. as such, an evolution from supercells to a more downdraft dominated convective mode is expected during this time. cold pool interaction would favor some consolidation, with the forecast thermodynamic environment favoring bowing segments with rear inflow jets over significant upscale growth. thus, the primary threat south of m59 appears to be largely a wind threat. certainly a very dynamic and fluid forecast situation with additional modifications to the official forecast reasoning anticipated during the next 12 hours. && long term...tuesday through sunday surface ridging tucked beneath continuous lower amplitude west- northwest mid level flow will result in a period of drier and more stable conditions tuesday and tuesday night. a limited period of weak cold air advection will be offset by the high regree of insolation within a modestly mixed environment. this will support highs of upper 70s and lower 80s. gradual boundary layer drying will provide a noticeable decrease in humidity by the latter half of the day. large scale pattern will deviate little heading into wednesday. west to east elongated strip of greater moisture/instability will remain anchored to the south through the daylight period...with additional shortwave energy working through this mean flow providing a focal point for continued convective development over the midwest/ohio valley. this positioning will sustain a higher degree of stability locally under deeper westerly flow. pattern peristence in the temperature department...highs again arriving within a degree or two on either side of 80 degrees. emerging warm air advection across the plains will favor some northeastward expansion of the main theta-e plume with time wednesday into thursday. this evolution could be augmented/enhanced by the passage additional shortwave energy. this will offer the next possibility for shower and thunderstorm development locally...centered sometime within the wednesday night and thursday periods. && marine... southerly winds will then increase today as strong low pressure tracks toward the northern great lakes. this system will bring the potential for strong to severe thunderstorms from late afternoon through tonight. while thunderstorms will be the primary concern...there will also be a period of stronger west to northwest winds along and behind a cold front tonight into tuesday. gust potential will be limited somewhat by stability over the cooler lake waters. however there will be the potential for some gusts to 30 knots across the open waters of lake huron...with 25 knots down through saginaw bay. this warrants the issuance of a small craft advisory for saginaw bay and along the tip of the thumb. the wind will decrease by late tuesday and tuesday night as high pressure builds into the region. && prev discussion...issued / && dtx watches/warnings/advisories... mi...none. lake huron...none. lake st clair...none. michigan waters of lake erie...none. && $$ short term...jvc long term....mr marine.......mr you can obtain your latest national weather service forecasts online at www.weather.gov/detroit (all lower case). hr. According to the 1:58 a.m. SPC update, the main threat for severe weather remains to the north and west of Toledo. And it seems that some aspects for severe weather have decreased for Michigan. The main risk for tornadoes and large hail exists over southern WI, northern IL, and eastern IA. But it appears that the NWS won't know for sure until mid-day. Excerpts from the 1:58 a.m., Mon, Jun 22 Day 1 Convective Outlook: q. ...upper ms valley/great lakes... *considerable uncertainty remains* regarding the forecast evolution of a severe mcs across the nrn plains into the upper ms valley prior to the start of the period. as a result... confidence for this severe forecast is tempered owing to several potentially critical variables 1) longevity/severity of early morning mcs from the ms valley into the great lakes 2) preferred storm mode /supercell and/or bow echo/. given relatively high uncertainty... *will defer substantial changes to the next outlook.* the next day 1 outlook is scheduled by 1300z [9:00 a.m. EDT] q.. br. !https://farm4.staticflickr.com/3767/18425440393_eb989ee46a_z.jpg! br. Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point. !https://farm1.staticflickr.com/400/18425440373_97340c7579_z.jpg! br. Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% or greater probability of wind gusts 65 knots or greater within 25 miles of a point. !https://farm1.staticflickr.com/412/18425440343_be6e8f1ffc_z.jpg! br. Probability of one inch diameter hail or larger within 25 miles of a point. Hatched Area: 10% or greater probability of two inch diameter hail or larger within 25 miles of a point. !https://farm1.staticflickr.com/327/18425440283_1530f8ec90_z.jpg! br. The cluster of strong storms located at 3:30 a.m. over the Dakotas and Minnesota may reach the lower Great Lakes later today. Warnings as of 3:34 a.m. EDT. !https://farm1.staticflickr.com/367/18425853753_e908aea21d_o.gif! br. Excerpts from the 2:35 a.m., Mon, Jun 22 AFD issued by the Det/Pon NWS, which is generally more informative than information from the Cle NWS, which seems to show little interest in Lucas County's weather. This AFD suggests that the worse weather for central and southern Michigan will occur after dark. Two rounds of storms may pass through Michigan. Thunderstorm scraps may reach the Toledo area after Midnight. q. an mcs is maturing over south dakota at press time in response to the previously discussed strong dynamic response across the northern united states and subsequent low-level jet response. high resolution models place the mcs on the expected ese trajectory over southern wisconsin by late this morning. low-level jet will only strengthen through the morning into this afternoon as the warm front lifts north. extrapolation puts perhaps the northern fringes of the mcs over south-central lower michigan by mid-afternoon, where the surface instability axis will already be firmly in place. any organized severe wind threat would likely only clip southwestern counties 20-00z. more likely scenario for this afternoon will be the potential for lead discrete development along the warm front in advance of mcs/remnants, possibly along mcs outflow propagating into the warm sector environment. the *initial threat before sundown* will be large hail to golf ball size and winds to 60 mph. lcls upwards of 3kft not particularly supportive of tornado development during this period. defined lull in activity is a reasonable expectation during mid evening hours probable given mcs passage and resultant mid-level latent heat bubble/stabilization and wake subsidence. ... *severe threat will fully mature during the late evening* ... ... will favor an initial mode of supercells over central lower michigan into the saginaw valley and locations north of m59. ... suggest very strong mesocyclone rotation capable of producing hail to golf balls or higher ... ... a legitimate tornadic threat would also exist during the supercell phase ... a few tornados cannot be ruled out mainly north of m59. magnitude of environmental wind field alone will also support straight line wind gust potential to 70 mph. [after 1:00 a.m. Tue] the primary threat south of m59 appears to be largely a wind threat. certainly a very dynamic and fluid forecast situation with additional modifications to the official forecast reasoning anticipated during the next 12 hours. q..