Stebo Posted March 13, 2016 Share Posted March 13, 2016 Why is he still even able to post? It's getting beyond old and he's been called out/corrected many many timesYeah it is getting tiring and it's been going on all winter long. Link to comment Share on other sites More sharing options...
HillsdaleMIWeather Posted March 13, 2016 Share Posted March 13, 2016 The 18Z GFS did get the near 60 degree dew points further north. (And to all the people on the Hillsdale Hate Train, take it off topic or to a PM) Link to comment Share on other sites More sharing options...
andyhb Posted March 13, 2016 Share Posted March 13, 2016 The 18Z GFS did get the near 60 degree dew points further north. (And to all the people on the Hillsdale Hate Train, take it off topic or to a PM) Oh lord. Link to comment Share on other sites More sharing options...
andyhb Posted March 13, 2016 Share Posted March 13, 2016 Have to say that model verification with dewpoints today isn't exactly giving me confidence in the moister solutions for Tuesday. Link to comment Share on other sites More sharing options...
Hoosier Posted March 13, 2016 Share Posted March 13, 2016 Have to say that model verification with dewpoints today isn't exactly giving me confidence in the moister solutions for Tuesday. You talking about what's going on where the current severe storms are happening? How far off are the models? Link to comment Share on other sites More sharing options...
andyhb Posted March 13, 2016 Share Posted March 13, 2016 You talking about what's going on where the current severe storms are happening? How far off are the models? Some models at least 4-5 degrees. Were forecasting 62-65 and they are struggling to get out of the upper 50s. Link to comment Share on other sites More sharing options...
Hoosier Posted March 13, 2016 Share Posted March 13, 2016 Some models at least 4-5 degrees. Were forecasting 62-65 and they are struggling to get out of the upper 50s. Ouch As far as Tuesday, not having the extra evapotranspiration boost at this time of year doesn't help, but I think if we can manage upper 50s dews then it should be enough for a pretty decent threat with the relatively steep mid level lapse rates. If anything more than that occurs, then would obviously even have a bigger threat. Link to comment Share on other sites More sharing options...
Chambana Posted March 13, 2016 Share Posted March 13, 2016 That cell just east of little rock Arkansas looks nasty, due towards the town of Carlisle. edit:it is tor warned. Link to comment Share on other sites More sharing options...
Geos Posted March 13, 2016 Share Posted March 13, 2016 For comparison purposes. April 9th, 2015 radar loop. Some similarities there like Andy was saying. Storms firing in eastern Iowa as supercells/individuals cell and later joined together further east. http://mesonet.agron.iastate.edu/GIS/apps/rview/warnings.phtml?autopilot=0&osite=DVN&tzoff=0&layers[]=nexrad&layers[]=warnings&layers[]=cwas&layers[]=uscounties&layers[]=watches&layers[]=blank&site=DVN&tz=CDT&archive=yes&year=2015&month=4&day=9&hour=20&minute=00&warngeo=both&zoom=250&imgsize=640x480&loop=1&frames=49&interval=10&filter=0&cu=0&sortcol=fcster&sortdir=0&lsrlook=%2B&lsrwindow=0 Link to comment Share on other sites More sharing options...
ClicheVortex2014 Posted March 14, 2016 Share Posted March 14, 2016 ILX has a really good discussion... answers some questions I've had All models continue to show deep layer shear associated with theupper wave as it becomes negatively tilted late in the day Tuesdaywith strong low level turning of the winds seen on the hodographs,especially off the NAM. 850 mb winds depicted on the ECMWF weresoutheasterly at 40-45 kts in the 21z-00z time frame across ournorth. SREF forecasts of surface dew points were a bit moreconservative on Tuesday afternoon, compared with the NAM, withmostly middle 50s forecast across our area, while the NAM near60 degree dew points which pushed SB cape values above 2500 J/KGover the eastern half of the forecast area Tuesday afternoon.Forecast soundings off the NAM and GFS continue to show a cappinginversion in place at least into the early afternoon hours beforelow level convergence starts to increase in the 925-850 mb layerjust ahead of the front, which should allow convection todevelop. The 4km NAM-WRF reflectivity simulations suggest thedevelopment of storms off to our east after 21z just ahead of theincreasing low level moisture convergence. However, if the timingoff the ECMWF is correct, storms will develop by mid afternoonfurther west, along or just west of Interstate 55 and streak east-northeast through the rest of the forecast area by 02z.Based off the low level wind profiles seen on the ECMWF, discretesupercells capable of large hail (with 700-500 mb lapse rates over7.0 C/KM) damaging winds and isolated tornadoes will be possiblefor a few hours, especially if the high dew points seen on the NAMverify, before cells consolidate into a fast moving line withmainly a damaging wind threat through late afternoon into earlyevening. If the GFS verifies, storms will develop in areas east ofI-55 and be out of our area by 00z. Still quite a bit of uncertaintywith the timing of the shortwave and attendant cold front for lateTuesday afternoon and evening. For now, will continue to mentionthe higher probabilities for damaging straight line winds and hailin the HWO for Tuesday, but as mentioned above, if the low levelmoisture increases more than what is advertised in most models,the tornado threat will start to become a concern as well Tuesdayafternoon. Link to comment Share on other sites More sharing options...
HillsdaleMIWeather Posted March 14, 2016 Share Posted March 14, 2016 FWIW Dew Points in Eastern Arkansas, Western Tennessee have finally started to breach the 60 degree mark. Link to comment Share on other sites More sharing options...
Hoosier Posted March 14, 2016 Share Posted March 14, 2016 Frontal position on the 00z NAM looks a tad east at 18z Tuesday...closer to the MS River. So possible we may see something of a compromise on timing between the 12z and 18z run. Link to comment Share on other sites More sharing options...
andyhb Posted March 14, 2016 Share Posted March 14, 2016 Frontal position on the 00z NAM looks a tad east at 18z Tuesday...closer to the MS River. So possible we may see something of a compromise on timing between the 12z and 18z run. Looks further south. Stronger low level shear is kind of close to outrunning the better instability axis this run. There's also a big weakness in 700 mb flow across E IL thanks to the shortwave ridging out ahead. That certainly would cause problems with storm mode/organization. Link to comment Share on other sites More sharing options...
Hoosier Posted March 14, 2016 Share Posted March 14, 2016 Looks further south. Stronger low level shear is kind of close to outrunning the better instability axis this run. There's also a big weakness in 700 mb flow across E IL thanks to the shortwave ridging out ahead. That certainly would cause problems with storm mode/organization. Yeah, not a fan of that. On the plus side, still trying to get 60 degree dewpoints up to around I-80. Link to comment Share on other sites More sharing options...
andyhb Posted March 14, 2016 Share Posted March 14, 2016 Yeah, not a fan of that. On the plus side, still trying to get 60 degree dewpoints up to around I-80. Seeing the same thing on the 4 km NAM. Instability axis displaced west of the best shear due to the lead shortwave ejecting NE early. Link to comment Share on other sites More sharing options...
Hoosier Posted March 14, 2016 Share Posted March 14, 2016 Link to comment Share on other sites More sharing options...
ClicheVortex2014 Posted March 14, 2016 Share Posted March 14, 2016 Interesting thing showing up on SREF. There's 2 concurrent maximums where severe storms are possible during the early evening. I'd imagine this suggests warm sector supercells near Louisville and a squall tracking from Des Moines to Chicago to extreme N IN Link to comment Share on other sites More sharing options...
Indystorm Posted March 14, 2016 Share Posted March 14, 2016 Well, tonight's NAM puts me in the game for svr weather Tues night. But honestly, the geographical location of the most intense storms has shifted on the NAM three times in three different runs this Sunday. Will just have to wait for more data to be ingested into the models. Link to comment Share on other sites More sharing options...
RyanDe680 Posted March 14, 2016 Share Posted March 14, 2016 If I were chasing, I think that northern IL and northern IN would be the sweet spot Link to comment Share on other sites More sharing options...
RyanDe680 Posted March 14, 2016 Share Posted March 14, 2016 Also interesting to see how far out the models had this. GFS at least. Link to comment Share on other sites More sharing options...
Hoosier Posted March 14, 2016 Share Posted March 14, 2016 If I were chasing, I think that northern IL and northern IN would be the sweet spot Really depends on which timing wins out. If it's the slower solutions, then I'd definitely favor Illinois...like I-39 area. Link to comment Share on other sites More sharing options...
RyanDe680 Posted March 14, 2016 Share Posted March 14, 2016 Really depends on which timing wins out. If it's the slower solutions, then I'd definitely favor Illinois...like I-39 area. That's why I went with a wide 400-500 mile area lol Link to comment Share on other sites More sharing options...
RyanDe680 Posted March 14, 2016 Share Posted March 14, 2016 This is an RC / Stebo question - during days where severe weather is forecasted such as what Tuesday is looking to be, how many mets are in the office during an outbreak like that? Are your shifts longer than usual? And does the SPC advise on watches/warnings? Link to comment Share on other sites More sharing options...
Stebo Posted March 14, 2016 Share Posted March 14, 2016 This is an RC / Stebo question - during days where severe weather is forecasted such as what Tuesday is looking to be, how many mets are in the office during an outbreak like that? Are your shifts longer than usual? And does the SPC advise on watches/warnings? In my case, I am an observer at an airport so it is just me on shift and a normal hour shift. RC would know more about the NWS office, I do know from my experience of interning though, they are staffed by several extra mets if possible for a potential severe weather day. Link to comment Share on other sites More sharing options...
The_Global_Warmer Posted March 14, 2016 Share Posted March 14, 2016 This is an RC / Stebo question - during days where severe weather is forecasted such as what Tuesday is looking to be, how many mets are in the office during an outbreak like that? Are your shifts longer than usual? And does the SPC advise on watches/warnings? I think the SPC decides all severe weather watches. Where as warnings come out of he local office. I'd think there would be coordination on warnings between the local office and spc and probably even coordination from nearby local offices helping track the severe storms. Sometimes you have upwards of a dozen active severe thunderstorm cells in one CWA constantly moving. In most cases where there is many cells whether on a linear line or clusters of supercells or discrete supercells they are typically moving very fast. I'd think a lot of time is wasted coordinating information to local emergency authorities. Which would inhibit actual tracking/forecasting of the storms. Getting your eye off the radar for even 5 minutes you can miss the formative stages of a tornadic look. Meaning that is missing crucial warning lead time. So yeah I'd guess coordinating is high on expected severe days Link to comment Share on other sites More sharing options...
Chinook Posted March 14, 2016 Share Posted March 14, 2016 Interesting thing showing up on SREF. There's 2 concurrent maximums where severe storms are possible during the early evening. I'd imagine this suggests warm sector supercells near Louisville and a squall tracking from Des Moines to Chicago to extreme N IN what does calibrated conditional probability of severe thunderstorm even mean, exactly? Why are you even posting this? Link to comment Share on other sites More sharing options...
ClicheVortex2014 Posted March 14, 2016 Share Posted March 14, 2016 what does calibrated conditional probability of severe thunderstorm even mean, exactly? Why are you even posting this? It's the probability of a thunderstorm being severe It's guidance that's showing what I think is an interesting signal. This is a discussion board. Why not? Link to comment Share on other sites More sharing options...
HillsdaleMIWeather Posted March 14, 2016 Share Posted March 14, 2016 Day 2 outlook holding off on enhanced, expanding East due to model uncertainty Link to comment Share on other sites More sharing options...
tornadohunter Posted March 14, 2016 Share Posted March 14, 2016 Take analogs for what they are worth but I did not expect 3/2/12 to be an analog. Link to comment Share on other sites More sharing options...
Paulie21 Posted March 14, 2016 Share Posted March 14, 2016 They kept off the Enhanced Risk due to the thermodynamic differences among the models. Most prone area mentioned for surface based convection was Illinois, however, storm mode is in question because of the new NAM had weakened wind fields at 850-700mb.If newer guidance were to ramp up the winds at lower levels, area of PVA over an uncapped warm sector could get nasty. Even with the weaker wind field, SPC mentioned a mix of semi-discrete cells and linear clusters. Moisture and storm morphology is what will define Tuesday. Link to comment Share on other sites More sharing options...
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