RCNYILWX Posted November 9, 2015 Share Posted November 9, 2015 Was looking forward to doing the forecast and AFD today for this event for LOT but unfortunately we're experiencing major technical difficulties in our system so MKX will be doing forecast for us today. Sent from my SM-G900V using Tapatalk Link to comment Share on other sites More sharing options...
Hoosier Posted November 9, 2015 Share Posted November 9, 2015 Low level shear really ramps up by 00z in IL/western IN but the surface instability axis lies farther west. Will be interesting to see how long tornadic storms can sustain. Link to comment Share on other sites More sharing options...
ClicheVortex2014 Posted November 9, 2015 Share Posted November 9, 2015 Always nice to have the storm still strengthening (quite quickly at that) during the event. Shear vectors are pointing 90 degrees away from the arcing dryline surge. Very strong vorticity advection. Can definitely see why the high-res models are keeping things fairly discrete through early evening. Pretty impressive given such strong forcing. With a storm speed of 60-70 MPH, the storms should outrun the front as well. Link to comment Share on other sites More sharing options...
Hoosier Posted November 9, 2015 Share Posted November 9, 2015 Was looking forward to doing the forecast and AFD today for this event for LOT but unfortunately we're experiencing major technical difficulties in our system so MKX will be doing forecast for us today. Sent from my SM-G900V That sucks. I think Gino pointed out something important in the overnight afd...this event has lower dewpoints for the LOT cwa than some of the CIPS analogs that produced severe weather. Still can't rule it out obviously. Link to comment Share on other sites More sharing options...
RCNYILWX Posted November 9, 2015 Share Posted November 9, 2015 How high dewpoints get is a tough call. 12z guidance does get low-mid 50s dewpoints into the CWA by Wednesday evening. Looking at the 12z CIPS, the #2 analog, 11/10/98 and the #4 analog, 11/16/1988, produced severe wind reports within the CWA with dewpoints reaching the mid 50s. Sent from my SM-G900V using Tapatalk Link to comment Share on other sites More sharing options...
Hoosier Posted November 9, 2015 Share Posted November 9, 2015 How high dewpoints get is a tough call. 12z guidance does get low-mid 50s dewpoints into the CWA by Wednesday evening. Looking at the 12z CIPS, the #2 analog, 11/10/98 and the #4 analog, 11/16/1988, produced severe wind reports within the CWA with dewpoints reaching the mid 50s. Sent from my SM-G900V I was looking at the 11/16/1988 analog more closely earlier, and it looks like the severe reports in LOT mainly came late in the evening on the 15th or perhaps just after midnight on the 16th. Looking at hourly obs from RFD and ORD, dews were actually a bit higher at that time...around 60. Link to comment Share on other sites More sharing options...
RCNYILWX Posted November 9, 2015 Share Posted November 9, 2015 I was looking at the 11/16/1988 analog more closely earlier, and it looks like the severe reports in LOT mainly came late in the evening on the 15th or perhaps just after midnight on the 16th. Looking at hourly obs from RFD and ORD, dews were actually a bit higher at that time...around 60.Ah okay, I was only looking at thumbnails on the CIPS page. If we had an extra day of moisture return ahead of this system, would be much more concerned for a fairly widespread outbreak, though mid 50s may be enough to at least get some severe into the CWA given everything else going for this. Link to comment Share on other sites More sharing options...
Hoosier Posted November 9, 2015 Share Posted November 9, 2015 Ah okay, I was only looking at thumbnails on the CIPS page. If we had an extra day of moisture return ahead of this system, would be much more concerned for a fairly widespread outbreak, though mid 50s may be enough to at least get some severe into the CWA given everything else going for this. fwiw, from what I can tell, the wind fields are better this time than November 1988, especially aloft. Link to comment Share on other sites More sharing options...
HillsdaleMIWeather Posted November 9, 2015 Share Posted November 9, 2015 Although it's not likely, the line could sustain through southern MI if the NAM verifies. also FWIW 12 GFS/NAM/ECMWF is more windy. First High Wind Watch up for the System: URGENT - WEATHER MESSAGENATIONAL WEATHER SERVICE DODGE CITY KS1216 PM CST MON NOV 9 2015...POWERFUL LOW PRESSURE SYSTEM WILL TRACK ACROSS CENTRAL PLAINSON VETERANS DAY....A VERY INTENSE LOW PRESSURE SYSTEM WILL MATURE ACROSS WESTERNKANSAS WEDNESDAY MORNING. AS THE LOW BEGINS TO MOVE INTO NORTHERNKANSAS BY MIDDAY, HIGH WINDS WILL DEVELOP IN ITS WAKE. HIGH WINDSARE LIKELY FROM LATE MORNING THROUGH THE AFTERNOON HOURSWEDNESDAY.KSZ030-031-043>046-061>066-074>081-084>090-100600-/O.NEW.KDDC.HW.A.0001.151111T1400Z-151111T2200Z/TREGO-ELLIS-SCOTT-LANE-NESS-RUSH-HAMILTON-KEARNY-FINNEY-HODGEMAN-PAWNEE-STAFFORD-STANTON-GRANT-HASKELL-GRAY-FORD-EDWARDS-KIOWA-PRATT-MORTON-STEVENS-SEWARD-MEADE-CLARK-COMANCHE-BARBER-INCLUDING THE CITIES OF...WAKEENEY...CEDAR BLUFF RESERVOIR...HAYS...ELLIS...SCOTT CITY...DIGHTON...NESS CITY...LA CROSSE...RUSH CENTER...SYRACUSE...LAKIN...DEERFIELD...GARDEN CITY...KALVESTA...JETMORE...HANSTON...LARNED...BURDETT...ST. JOHN...STAFFORD...HUDSON...JOHNSON CITY...ULYSSES...SUBLETTE...SATANTA...CIMARRON...MONTEZUMA...DODGE CITY...BUCKLIN...KINSLEY...LEWIS...GREENSBURG...HAVILAND...PRATT...ELKHART...RICHFIELD...HUGOTON...MOSCOW...LIBERAL...KISMET...MEADE...FOWLER...ASHLAND...MINNEOLA...COLDWATER...PROTECTION...MEDICINE LODGE...KIOWA...SUN CITY1216 PM CST MON NOV 9 2015 /1116 AM MST MON NOV 9 2015/...HIGH WIND WATCH IN EFFECT FROM WEDNESDAY MORNING THROUGHWEDNESDAY AFTERNOON...THE NATIONAL WEATHER SERVICE IN DODGE CITY HAS ISSUED A HIGH WINDWATCH...WHICH IS IN EFFECT FROM WEDNESDAY MORNING THROUGHWEDNESDAY AFTERNOON.* TIMING...LATE MORNING THROUGH AFTERNOON WEDNESDAY.* WINDS...NORTHWEST AT 35 TO 45 MPH WITH GUSTS TO 60 MPH.* IMPACTS...INTENSE CROSSWINDS ON OPEN HIGHWAYS WILL MAKE TRAVELDIFFICULT, ESPECIALLY AROUND GRAIN ELEVATORS. LIGHT STRUCTURALDAMAGE IS POSSIBLE, ESPECIALLY TO ROOFS. SOME COMMERCIAL POWERINTERRUPTION IS ALSO POSSIBLE.PRECAUTIONARY/PREPAREDNESS ACTIONS...A HIGH WIND WATCH MEANS THERE IS THE POTENTIAL FOR A HAZARDOUSHIGH WIND EVENT. CONTINUE TO MONITOR THE LATEST FORECASTS.&&$UMSCHEID Link to comment Share on other sites More sharing options...
Hoosier Posted November 9, 2015 Share Posted November 9, 2015 North of STL at 00z Thursday...lots of shear Link to comment Share on other sites More sharing options...
ClicheVortex2014 Posted November 9, 2015 Share Posted November 9, 2015 I just looked at ILN's criteria for high wind watch/warnings and wind advisories... looks like we're gonna have a high-end wind advisory. If the criteria is the same for North Illinois, they might barely meet the criteria for high wind watch (gusts >58 MPH)... but certainly, the lower GL should light up with wind advisories. Link to comment Share on other sites More sharing options...
Hoosier Posted November 9, 2015 Share Posted November 9, 2015 I almost wonder if 700-500 mb lapse rates may not be as crucial in this setup...I'm not saying to ignore and that they don't matter, but a lot of the forecast soundings I've been looking at don't even have the EL reaching up to 500 mb, especially as you move farther east. I think something like 850-700 mb lapse rates may be better. Link to comment Share on other sites More sharing options...
bdgwx Posted November 9, 2015 Share Posted November 9, 2015 I almost wonder if 700-500 mb lapse rates may not be as crucial in this setup...I'm not saying to ignore and that they don't matter, but a lot of the forecast soundings I've been looking at don't even have the EL reaching up to 500 mb, especially as you move farther east. I think something like 850-700 mb lapse rates may be better. I have to agree with you here. If this is going to be a low topped supercell threat then perhaps we should be focusing more on the 0-3km CAPE values anyway. And some of them from yesterday looked pretty potent. I haven't looked at any today and I don't have access to my normal tools. Perhaps some of you guys can post a SHARPpy sounding or two or at least report on what the low level CAPE is looking like? Link to comment Share on other sites More sharing options...
A-L-E-K Posted November 9, 2015 Share Posted November 9, 2015 looking forward to my breezy showers best action looks to be right in the heart of the NE Missouri radar dead zone Link to comment Share on other sites More sharing options...
Hoosier Posted November 9, 2015 Share Posted November 9, 2015 18z NAM coming in slightly better with dewpoints, could just be noise level changes though. Link to comment Share on other sites More sharing options...
Gilbertfly Posted November 9, 2015 Share Posted November 9, 2015 15z Plume at JOT brings the mean DP to 52 ...not incredibly high...but the trend has been upticking a bit Link to comment Share on other sites More sharing options...
Thundersnow12 Posted November 9, 2015 Author Share Posted November 9, 2015 18z NAM coming in slightly better with dewpoints, could just be noise level changes though. It also has a little more instability across IA Link to comment Share on other sites More sharing options...
ClicheVortex2014 Posted November 9, 2015 Share Posted November 9, 2015 ILX has another good AFD SPC has most of the CWA in a slight risk of severe weather for Wedalong with an enhanced risk area in southwest parts of the CWA. WithBulk Shear at 0-6km over 80kts and 0-3km SRH over 400 m/s, believestorms/strong showers that develop will likely rotate. With dwptsonly getting into the 50s in IL, instability may be limited, butmodels continue to show near 500 CAPE in southeast IA, west IL, andnortheast MO. This is also where some of the best wind turning willbe as it is closes area to the sfc low moving across IA. With highermoisture being southwest of the area, agree with SPC that enhancedarea should be where best instability should be. Besides the limitedmoisture, another negative with this event will be the storms shouldbe moving around 50 mph...which combined with the strong shear, theupdrafts could have trouble holding together. Looking at everything,still believe strong to severe weather is likely in our CWAbeginning last Wed afternoon through Wed evening. Mid and upperlevel lapse rates do not look high enough to support hail with thisevent, so thinking is that main severe weather concern will bedamaging winds. With ML LCLs forecasted to be below 500m and theenvironment being High Shear/Low CAPE, think a few tornadoes willalso be possible. Will definitely take a closer look at the modelsthe next several runs. Link to comment Share on other sites More sharing options...
HillsdaleMIWeather Posted November 9, 2015 Share Posted November 9, 2015 IWX had a somewhat rushed feeling afternoon AFD, I still feel they are underestimating the wind threat. Link to comment Share on other sites More sharing options...
cyclone77 Posted November 9, 2015 Share Posted November 9, 2015 Since there's a good shot that this thing kicks off early, the best tor threat may be fairly early on way out west over southeast NE/southwest IA near cold core center. NAM has consistently forecast cape at it's highest earlier in the day as well. If I were chasing I'd probably plan on heading out to southwestern IA and hope I didn't have to head even further west into NE, which is possible. Link to comment Share on other sites More sharing options...
Chitown Storm Posted November 9, 2015 Share Posted November 9, 2015 the 18z NAM showing a secondary piece of energy dropping in from the NW that puts down a hit of accumulating snow in eastern MN/western WI on the heels of the main storm. We might have the full gauntlet across the sub forum. Link to comment Share on other sites More sharing options...
Hoosier Posted November 9, 2015 Share Posted November 9, 2015 If the general model solutions hold, I'd bet on a northward expansion of the enhanced risk area especially in IA/IL. Actually I think you could make a case that the northern area looks as good if not better than farther south. Link to comment Share on other sites More sharing options...
ClicheVortex2014 Posted November 9, 2015 Share Posted November 9, 2015 LMK has an interesting take Wednesday will be dry as surface high pressure and progressive upperridge axis hold over our region. A steady south wind and mostlysunny to partly cloudy skies will allow temps to rise into the upper60s and low 70s in some spots during the afternoon.Upstream, a potent upper system (characterized by 150 kt upper leveljet, and 100-110 kt 500 mb jet) will eject out of the southernPlains and into the mid Mississippi River Valley by Wednesdayevening. 500 mb trough will take on a negative tilt during thistransition. Associated surface low will deepen as it moves fromwestern KS to western IA. Strong upper divergence will overspreadthe mid Mississippi and Ohio River Valleys through the afternoon andinto the evening hours, resulting in a strong low level jet (50-60kts) response. At the surface, SSE winds will increase in responseto the pressure falls. Expecting to see 15 to 20 mph, occasionallygusting around 25-30 mph Wednesday evening into Wednesday night.Wind fields are undoubtedly impressive, however question continuesto remain with regard to instability. Surface based instability axiscontinues to look meager to non-existent as only a very narrowcorridor of 55-60 dew points will build ahead of the cold front.Despite the lack of instability, still think pockets of gusty topotentially damaging winds will be possible within strongly forcedline via a couple of bowing segments, particularly across ourwestern CWA. Organized line of storms should overall weaken as theyprogress east through the overnight.Also, am a bit concerned about a secondary line of showers/stormsright along the frontal boundary, which seems to coincide with thebest instability axis. Low level theta surfaces become verticalduring this time which could allow 30 to 40 mph gradient wind gusts.Gust potential could then be enhanced by any shower/storm. It isentirely possible that this could be the worst part of the event,with the pre-frontal trough acitivity too elevated for wind damageand mainly just gusty stratiform rain. Either way, the main threatWednesday evening will be gusty winds, with a few pockets ofdamaging winds likely. Rainfall totals really don`t look all thatimpressive given the speed that the system moves through. A briefspin-up tornado threat is non-zero, but at this point seems prettyunlikely given the unimpressive dew points and the lack of at leasta little bit of surface based instability. Link to comment Share on other sites More sharing options...
Chicago Storm Posted November 9, 2015 Share Posted November 9, 2015 If the general model solutions hold, I'd bet on a northward expansion of the enhanced risk area especially in IA/IL. Actually I think you could make a case that the northern area looks as good if not better than farther south.This. I'd bring the slight as far north as S. WI/SW. MI and shift the enhanced north from SGF-PAH up to I-80. Link to comment Share on other sites More sharing options...
andyhb Posted November 9, 2015 Share Posted November 9, 2015 If the general model solutions hold, I'd bet on a northward expansion of the enhanced risk area especially in IA/IL. Actually I think you could make a case that the northern area looks as good if not better than farther south. It's becoming kind of obvious that Broyles doesn't really look at a lot of things before issuing his outlooks (or at least it really comes across that way). That 06z D1 outlook for 4/9 is another case, where parts of it literally made zero sense. Link to comment Share on other sites More sharing options...
HillsdaleMIWeather Posted November 9, 2015 Share Posted November 9, 2015 It's becoming kind of obvious that Broyles doesn't really look at a lot of things before issuing his outlooks (or at least it really comes across that way). That 06z D1 outlook for 4/9 is another case, where parts of it literally made zero sense. For those who need a refresher on that -Note that the wind report in Hillsdale and few other places are later verified tornadoes: Link to comment Share on other sites More sharing options...
Hoosier Posted November 9, 2015 Share Posted November 9, 2015 It's becoming kind of obvious that Broyles doesn't really look at a lot of things before issuing his outlooks (or at least it really comes across that way). That 06z D1 outlook for 4/9 is another case, where parts of it literally made zero sense. I'm speculating here but I think it's possible there's some thought to be conservative with northern target areas in November, given that instability is often lackluster. I think there's enough consistency at this point to expand it north on the day 2 outlook later. Link to comment Share on other sites More sharing options...
Stebo Posted November 9, 2015 Share Posted November 9, 2015 This. I'd bring the slight as far north as S. WI/SW. MI and shift the enhanced north from SGF-PAH up to I-80. Yeah I would agree with this sort of orientation. Link to comment Share on other sites More sharing options...
andyhb Posted November 9, 2015 Share Posted November 9, 2015 Well that's interesting... Link to comment Share on other sites More sharing options...
Indystorm Posted November 9, 2015 Share Posted November 9, 2015 I'm liking the area from St. Louis to Quad Cities based on the 18z NAM with STP of 3 to 5 this run for late Wed. Link to comment Share on other sites More sharing options...
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