Powerball

Called it.

Thread should probably be extended to include the 19th, for the Eastern GL and OH Valley. I wouldn't be surprised if the slight risk area gets expanded back NW to Detroit and Toledo, although it is contingent on how tonight's activity evolves. SPC AC 180558 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Sat Jul 18 2020 Valid 191200Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN OH INTO NORTHWESTERN PA AND WESTERN NY... ...SUMMARY... Isolated strong to severe thunderstorms may occur Sunday from portions of the Great Lakes/Ohio Valley regions into the mid Mississippi Valley and parts of the Plains. Damaging winds and large hail should be the main threats. ...Great Lakes into the Ohio Valley and Western New York... An MCS may be ongoing at the start of the period Sunday morning across parts of Lower MI, with additional convection possible farther south into northern IL/IN. This MCS should decay quickly across Lower MI and vicinity as it encounters substantial convective inhibition with eastward extent across the Great Lakes region. Depending on its organization, it may still pose an isolated threat for damaging winds before it weakens/dissipates. In the wake of this morning activity, an upper trough is forecast to move east-northeastward from the Upper Midwest/Great Lakes into Ontario and Quebec through the period. A surface low should likewise develop northeastward across Ontario/Quebec through the day. A cold front trailing southwestward from this low across the Great Lakes/Upper Midwest should shift east-southeastward. Diurnal heating of a rather moist low-level airmass will likely foster moderate to potentially strong instability ahead of the front by Sunday afternoon. The stronger large-scale ascent associated with the upper trough should remain in Canada. Regardless, low to mid-level westerly flow is forecast to strengthen through the day across parts of the OH Valley into western PA/NY. A corresponding modest increase in effective bulk shear to around 25-35 kt will probably be sufficient for storm organization. Current expectations are for scattered storms to develop along/ahead of the front Sunday afternoon across northern IN/OH. Additional convection may advance eastward from southern Ontario across Lakes Erie/Ontario, and into northwestern PA and western NY by early Sunday evening. Clusters/small bows should the main storm mode. With steepened low-level lapse rates and enhanced low/mid-level flow across these areas, at least isolated damaging wind gusts may occur. Isolated instances of marginally severe hail also appear possible. Confidence has increased enough regarding this scenario to include 15% severe wind probabilities and a corresponding Slight Risk from northern OH into western NY. Storms should gradually weaken Sunday evening farther east into central PA/NY as they encounter less instability.

With temps just getting to 80*F at 12pm, I can't see how 90*F happens here today (even with full sunshine). Obviously mixing heights are shot. There's still several hours of heating left to go though, so we'll see.

DET did tag an intra-hour 90*F before the storms moved in, but unfortuntely DTW wasn't so lucky only making it to 87*F. So the 90*F+ streak officially ended yesterday, after 8 consecutive days.

It's going to be a race against time today. Starting off warm with a temp of 77*F, clear skies and 925mb temps of 25*C, but the clouds and convection are steadily moving NE. Most models still have us tagging 90*F though, which would make it the 9th consecutive day for Detroit.

Nothing here, but areas around Highland Park and immediately to the west have a flash flood warning and severe thunderstorm warning.

The lake breeze storms kicked off early today as I'm hearing thunder now. After hitting an intra-hour 91*F, DET has fallen back down to 85*F.

Damn...

The lake breeze front off Lake St. Clair clashed with a nice outflow boundary from storms in the Tri-Cities earlier, giving us a nice drenching t'storm right now.

DTX has issued a Heat Advisory for today and an Excessive Heat Watch is in effect through Thursday evening.

Obviously we're not looking at another dust bowl, but given the current model projections, this map of drought conditions in the SW plains has to be a bit concerning from the standpoint of a positive feedback loop for temperatures.

That's almost as ridiculous as the lieutenant Gov. in Texas saying Grandma should sacrifice herself for young people.

DTW managed an intra-hour 90*F today, so the streak continues...

This morning's AFD mentions there will likely be a need for Heat Advisories this upcoming week. That said, for now, the humidity has been manageable which is keeping heat indices in check.

Indications suggest this time may be different. The long range pattern isn't looking too dissimilar from 1995 and 2012.

It's looking like there will be just enough flattening of the ridge next weekend to at least bring a temporary "cool down" (meaning sub-90*F+ temps) for the NE parts of the subforum. From what I recall, shortwaves like the one showing up on the models right now always end up breaking down the ridge more than projected in the mid/long range.

I've been back in town and will be here for at least the next week. You're welcome for the heat.

Based on the archive radar, Windsor probably saw even bigger hail. There was some good magenta color in that cell before it crossed the river.

NE Wayne County into Southern Macomb County seem like it got hit pretty good.

The outflow boundary from the line of storms is causing more storms to blow up over the east side of Detroit now. Not severe right now, but they're looking healthy.

The squall line's progression eastward looks to have slowed to a crawl. In the mean time, now there are some nice supercells popping up along the I-75 corridor as the cap weakens.

Severe Thunderstorm Warning MIC093-161-102030- /O.NEW.KDTX.SV.W.0024.200610T1921Z-200610T2030Z/ BULLETIN - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Warning National Weather Service Detroit/Pontiac MI 321 PM EDT Wed Jun 10 2020 The National Weather Service in Detroit/Pontiac has issued a * Severe Thunderstorm Warning for... Livingston County in southeastern Michigan... Washtenaw County in southeastern Michigan... * Until 430 PM EDT. * At 320 PM EDT, severe thunderstorms were located along a line extending from near Perry to 6 miles southwest of Vandercook Lake, moving northeast at 40 mph. HAZARD...70 mph wind gusts. SOURCE...Radar indicated. IMPACT...Expect considerable tree damage. Damage is likely to mobile homes, roofs, and outbuildings. * Severe thunderstorms will be near... Fowlerville around 325 PM EDT. Cohoctah around 335 PM EDT. Chelsea around 400 PM EDT. Gregory around 405 PM EDT. Dexter around 410 PM EDT. Pinckney around 415 PM EDT. Hamburg around 420 PM EDT. Whitmore Lake around 425 PM EDT. Other locations impacted by these severe thunderstorms include Pittsfield Township, Whittaker, Plainfield, Hudson Mills Metropark, Island Lake State Recreation Area, Bridgewater, Delhi Mills, Pleasant Lake, Barton Hills and Pinckney State Recreation Area. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. This is a DANGEROUS SITUATION. These storms are producing widespread wind damage across southern Lower Michigan. SEEK SHELTER NOW inside a sturdy structure and stay away from windows! Torrential rainfall is occurring with these storms, and may lead to flash flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 4278 8369 4243 8366 4243 8355 4209 8354 4208 8413 4278 8416 TIME...MOT...LOC 1920Z 234DEG 35KT 4275 8419 4213 8449 HAIL...<.75IN WIND...70MPH

Looking at the satellite image, it kind of looks like some gravity waves in that area.

Watch out Detroit... Mesoscale Discussion 0900 NWS Storm Prediction Center Norman OK 0203 PM CDT Wed Jun 10 2020 Areas affected...southeast lower Michigan Concerning...Severe Thunderstorm Watch 274...276... Valid 101903Z - 102030Z The severe weather threat for Severe Thunderstorm Watch 274, 276 continues. SUMMARY...Numerous thunderstorms have coalesced into a loosely organized squall line across portions of northeast Indiana and southeast Lower Michigan. A focused corridor for damaging wind gusts may develop as storms intensify from Kalamazoo, east-northeast toward Detroit. DISCUSSION...A line of quasi discrete supercells have begun merging into a more linear organization across portions of northeast Indiana and southern half of Lower Michigan over the last hour. Several reports of wind damage have been received as outflow has become more coherent and better organized. The diagonal NE/SW orientation of the convective line lies along a corridor of backed mid and upper-level flow observed from the 18z Detroit special sounding. The orientation of the upper-level flow will likely support continued downdraft development and outflow aggregations given seeding from anvil precipitation being advected over downstream convection across portions of far northeast Indiana into southeast Lower Michigan. The main threat with storms will be damaging winds given 1200-1400 J/kg of DCAPE and strong mid-level flow of 50 to 60 kt. Large hail will be possible given MLCAPE of 1000-1500 J/kg supporting robust deep updrafts. However, the risk appears limited due to weaker lapse rates of 6 to 7 C/km and the predominately linear storm mode. The most favored corridor for severe wind will be with the stronger cells merging into southern Michigan toward Detroit. A few significant wind gusts will be possible with any stronger bowing structures that can develop. ..Lyons/Thompson.. 06/10/2020 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DTX...IWX...GRR... LAT...LON 42648519 43208407 43788343 43908295 43668264 42728254 42418300 41768352 41818523 42048528 42548522 42648519

Mesoscale Discussion 0899 NWS Storm Prediction Center Norman OK 1258 PM CDT Wed Jun 10 2020 Areas affected...western and central Ohio into northern Kentucky Concerning...Severe potential...Watch likely Valid 101758Z - 101930Z Probability of Watch Issuance...95 percent SUMMARY...A new Severe Thunderstorm Watch downstream of WW275 will likely be issued within the next hour. Severe thunderstorms capable of damaging wind gusts, isolated large hail, and a tornado or two will be likely through this afternoon. DISCUSSION...A broken line of thunderstorms over central Indiana has produced several reports of damaging winds over the last few hours. These storms are ongoing in a very moist environment (surface dewpoints in the low to mid 70s F) ahead of a pressure trough/wind shift emanating from a 983 mb cyclone over southern Ontario. 1500-2000 J/kg of MLCAPE, and 35-45 kt of effective shear as sampled by SPC mesoanalysis will support robust organized updrafts in the form of small bowing segments and supercells. Damaging winds will primarily be the main threat with the increase in storm coverage and interactions favoring strong downdrafts. However, the magnitude of instability/buoyancy will support some risk for isolated large hail with the strongest updrafts. Hodographs are expected to be relatively long but low-level flow is expected veer with time supporting the threat for one or two tornadoes given 0-1 km shear of 15-20 kt. A new Severe thunderstorm Watch will be needed within the next hour. ..Lyons/Thompson.. 06/10/2020 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PBZ...RLX...CLE...ILN...LMK...IWX...IND... LAT...LON 38588362 38398438 38378477 38618517 39278531 40988426 41588381 41648364 41568290 41628214 41738178 41818152 41758140 39808209 39468230 38828298 38588362