homedis Posted November 19, 2015 Share Posted November 19, 2015 Canadian actually still drops 6 to 12 across most of LOT (what accumulates could be different thanks to compaction, melting, etc. etc. etc.)....lolli's in the favored LE areas Favoite model run so far... I'm right in bulleye Link to comment Share on other sites More sharing options...
Gilbertfly Posted November 19, 2015 Share Posted November 19, 2015 soil temps will be fine by the time this system rolls into the LOT area...especially with onset of precip coming at a time when soil temps will be at their lowest. Pavement is a bit trickier depending on how much sun we get on Friday before the high clouds start to roll in Link to comment Share on other sites More sharing options...
Jonger Posted November 19, 2015 Share Posted November 19, 2015 I have had a solid week of 70 degree spring temps and had snow stick to pavement during a rain to snow event. sub-freezing snowflakes cool the ground FAST. Link to comment Share on other sites More sharing options...
SchaumburgStormer Posted November 19, 2015 Share Posted November 19, 2015 soil temps will be fine by the time this system rolls into the LOT area...especially with onset of precip coming at a time when soil temps will be at their lowest. Pavement is a bit trickier depending on how much sun we get on Friday before the high clouds start to roll in Yeah. I think the idea of warm ground/pavement is being overblown a bit. With a large majority of the snow progged to fall overnight, and the models showing some pretty good banding; I think the pavement may have some slush on the onset, but will accumulate rapidly. That being said, well traveled roads and tollways may not have as much of an issue, especially if salted early. Granted, we have seen the opposite to be true too, with cold ground temps causing ice issues with rain. But as said above, all other factors notwithstanding, I don't think ground temps are going to be a major factor for those in the best snow bands. Link to comment Share on other sites More sharing options...
Hoosier Posted November 19, 2015 Author Share Posted November 19, 2015 I think we will see the envelope tighten with the 00z cycle. All the players will be fully on land by then. Link to comment Share on other sites More sharing options...
Chicago Storm Posted November 19, 2015 Share Posted November 19, 2015 I actually agree with those that don't think ground temps will be a too significant of an issue. I want to throw out one recent example... 10/22/13 featured up to 3" of snow in area near I-80. The snow occurred in the late morning-early afternoon hours. Temperatures at the time were in the 30's and soil temps in the low-mid 40's. Additionally, in the days leading up to this event high temps were in the 50's and 60's, with even 70-80F temps just about 10 days prior. Link to comment Share on other sites More sharing options...
Hoosier Posted November 19, 2015 Author Share Posted November 19, 2015 PURDUEWX80, I got your PM but am not able to respond (have had this problem with some other people for some reason). Send your message to another staff member. Link to comment Share on other sites More sharing options...
Gilbertfly Posted November 19, 2015 Share Posted November 19, 2015 wpc leaning a bit away from the GFS.... DEEPENING SURFACE LOW/UPPER TROUGH OVER THE MIDWEST/GREAT LAKES SAT~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~PREFERENCE: A BLEND...2/3 WEIGHT 00Z ECMWF OR 00Z NAM 1/3 WEIGHT 12Z GFSCONFIDENCE: AVERAGETRENDS IN THE ENSEMBLE SPAGHETTI PLOTS FOR THE 552 DM HEIGHT LINEAT 500 MB HAVE SHOWN A TREND OVER THEIR PAST 4 CYCLES TOWARD THESLOWER/DEEPER SIDE OF THE ENSEMBLE SPREAD VALID 00Z/21 OVER THEHIGH PLAINS. THE RESULT HAS BEEN A SURFACE LOW ALSO TRENDINGSLOWER/BACK TOWARD THE WEST. THE 12Z GFS IS ON THE FASTER SIDE OFTHE ENSEMBLE/DETERMINISTIC SPREAD THROUGH 12Z/21 WITH THE SURFACELOW...WHILE THE 12Z NAM AND 00Z ECMWF SHOW VERY SIMILARLY TOWARDTHE BETTER ENSEMBLE CLUSTERING.HOWEVER THIS CHANGES BY 00Z/22...AS THE NAM/ECMWF END UP TOWARDTHE EAST/FASTER SIDE OF THE ENSEMBLES...WHILE THE 12Z GFS ISTOWARD THE MIDDLE/WEST/SLOWER SIDE. THEREFORE...WEIGHT OF GUIDANCEAPPEARS TO BE MORE EVEN AMONG THE NAM/GFS/ECMWF AT 00Z/22 ANDONWARD...BUT THIS IS WHEN MOST OF THE SNOW IMPACTS TO THE LOWER 48HAVE ENDED AND THE SURFACE LOW IS MOVING INTO SRN CANADA.IN SUMMARY...SOME WEIGHT TOWARD THE GFS IS INCLUDED IN THEPREFERENCE...BUT MORE WEIGHT IS PREFERRED TO BE WITH THE NAM/ECMWFFOR THIS SYSTEM. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted November 19, 2015 Share Posted November 19, 2015 AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 1142 AM CST THU NOV 19 2015 UPDATE 1140 AM CST NO MAJOR CHANGES THIS MORNING. HAVE EXTENDED THE WINTER STORM WATCH THROUGH 3 PM SATURDAY TO ACCOUNT FOR ANTICIPATED ONGOING SNOWFALL CONTINUING DURING THE EARLY-MID AFTERNOON SATURDAY...ESPECIALLY IN THE EASTERN PART OF THE WATCH AREA /CHICAGO METRO PART/. THE 12Z GUIDANCE CONTINUES TO SUPPORT A 15-18 HOUR SNOWFALL EVENT ACROSS A MAJORITY OF THE FORECAST AREA ON FRIDAY NIGHT AND SATURDAY. THERE MAINTAINS A COUPLE MODELS OR ENSEMBLE MEMBERS WITH A NORTHWARD TRACK...WHILE MOST OF THE OTHERS SLIGHTLY SOUTH AND ORIENTED MORE WEST-TO-EAST WITH THEIR HEAVIEST FORCING AND RESULTANT SNOW BASICALLY CENTERED MORE ON THE I-88 CORRIDOR. THIS WOULD RESULT IN POTENTIAL FOR MORE ACCUMULATION INTO THE HEART OF THE CHICAGO METRO AREA. CONTINUE TO LOOK INTO TEMPERATURES AND THEIR IMPACTS...AS THAT MAY REALLY LIMIT ACCUMULATION FRIDAY EVENING. SYNOPTIC SCALE LIFT AND FORCING LOOKS TO BE ENOUGH FROM PRE-DAWN SATURDAY THROUGH EARLY SATURDAY AFTERNOON TO OVERWHELM ANY LOW-LEVEL WARMTH FOR DECENT RATES AND QUICKER ACCUMULATION. THAT IS ONE REASON WHY HAVE EXTENDED THE WATCH TO 3 PM CST SATURDAY. WE WILL CONTINUE TO INTERROGATE THE SUITE OF MODEL GUIDANCE AND VARIOUS ELEMENTS TOWARD THE WINTER WEATHER EVENT INTO EARLY THIS AFTERNOON...ALONG WITH A CONFERENCE CALL WITH WPC AND ADJACENT WFOS SHORTLY...AND WILL HAVE MORE WITH A LATER AFD. MTF Link to comment Share on other sites More sharing options...
Hoosier Posted November 19, 2015 Author Share Posted November 19, 2015 I actually agree with those that don't think ground temps will be a too significant of an issue. I want to throw out one recent example... 10/22/13 featured up to 3" of snow in area near I-80. The snow occurred in the late morning-early afternoon hours. Temperatures at the time were in the 30's and soil temps in the low-mid 40's. Additionally, in the days leading up to this event high temps were in the 50's and 60's, with even 70-80F temps just about 10 days prior. I agree too...I think any areas that are able to drop near or below freezing should start seeing it stick on the pavement given sufficient snowfall rates. Link to comment Share on other sites More sharing options...
Jonger Posted November 19, 2015 Share Posted November 19, 2015 NAM would be 6-10 inches for me. Looking like one of my best November storms since 11-29-2011. Link to comment Share on other sites More sharing options...
A-L-E-K Posted November 19, 2015 Share Posted November 19, 2015 GEFS south of OP \ Link to comment Share on other sites More sharing options...
Thundersnow12 Posted November 19, 2015 Share Posted November 19, 2015 Euro coming in south/weaker too Link to comment Share on other sites More sharing options...
HillsdaleMIWeather Posted November 19, 2015 Share Posted November 19, 2015 When the WPC feels your too north, your probably WAY too north. NAM would be 6-8 for me. Link to comment Share on other sites More sharing options...
harrisale Posted November 19, 2015 Share Posted November 19, 2015 There's definitely some credence to the warm ground argument. It plays into the overall radiation balance in the atmosphere. Warmer soil is simply going to emit more long wave radiation, that can't be ignored. It would even have some effect on boundary layer temperatures (although not to the degree of the lakes). Now I'm not saying its going to turn 6" of snow into 1" of slush, as one poster put it. But it certainly will melt snow falling on bare ground, particularly if rates are low. But high enough rates would overcome this effect and a coating would quickly limit this effect and insulate the boundary layer from warmer temps in the soil. So I could see this maybe taking an 1"-1.5" or so off totals totals on the models, with this effect having a lesser effect where rates are heaviest. Locally, 3 of the last 4 days here have featured highs of 56F or more, with last night not even dropping below 55F. Thinking this could reduce totals around here, particularly since we are only looking at a few hours of below freezing temperatures before the event starts. On another note, wondering how the Chicago slush fest will affect the power grid? I remember Alek saying there are still leaves on the trees in the area. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted November 19, 2015 Share Posted November 19, 2015 Yikes. Quite weaker Link to comment Share on other sites More sharing options...
SchaumburgStormer Posted November 19, 2015 Share Posted November 19, 2015 Looking like time to fuel up the snowblower. Even if the lower totals verify, it will be so heavy that it will be miserable to move. Link to comment Share on other sites More sharing options...
HillsdaleMIWeather Posted November 19, 2015 Share Posted November 19, 2015 12Z ECMWF Snow Maps are looking reasonable so far. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted November 19, 2015 Share Posted November 19, 2015 Still looks like 6-7" across I-88 into Chicago but the surface reflection looks pretty meh Link to comment Share on other sites More sharing options...
Chicago Storm Posted November 19, 2015 Share Posted November 19, 2015 Euro coming in south/weaker tooVery much so. Link to comment Share on other sites More sharing options...
Geos Posted November 19, 2015 Share Posted November 19, 2015 There's definitely some credence to the warm ground argument. It plays into the overall radiation balance in the atmosphere. Warmer soil is simply going to emit more long wave radiation, that can't be ignored. It would even have some effect on boundary layer temperatures (although not to the degree of the lakes). Now I'm not saying its going to turn 6" of snow into 1" of slush, as one poster put it. But it certainly will melt snow falling on bare ground, particularly if rates are low. But high enough rates would overcome this effect and a coating would quickly limit this effect and insulate the boundary layer from warmer temps in the soil. So I could see this maybe taking an 1"-1.5" or so off totals totals on the models, with this effect having a lesser effect where rates are heaviest. On another note, wondering how the Chicago slush fest will affect the power grid? I remember Alek saying there are still leaves on the trees in the area. Probably not enough trees with leaves to make a real big impact. Snow accumulation probability for 4" and 8". Link to comment Share on other sites More sharing options...
A-L-E-K Posted November 19, 2015 Share Posted November 19, 2015 Still looks like 6-7" across I-88 into Chicago but the surface reflection looks pretty meh best case scenario for MBY and keeping the marine influence to a minimum Link to comment Share on other sites More sharing options...
wisconsinwx Posted November 19, 2015 Share Posted November 19, 2015 GEFS south of OP \ Shocker of the century. Link to comment Share on other sites More sharing options...
mimillman Posted November 19, 2015 Share Posted November 19, 2015 Very much so. Big lake effect signal on the Euro right over your's truly. Link to comment Share on other sites More sharing options...
HillsdaleMIWeather Posted November 19, 2015 Share Posted November 19, 2015 12Z Euro looks like it's actually too weak. It has the system rapidly weaken as it crosses into Illinois, and again crossing Lake MI, there are nothing on it support that happening, so outlier. Link to comment Share on other sites More sharing options...
mimillman Posted November 19, 2015 Share Posted November 19, 2015 Link to comment Share on other sites More sharing options...
mimillman Posted November 19, 2015 Share Posted November 19, 2015 best case scenario for MBY and keeping the marine influence to a minimum I would gladly take a blend of the ECMWF, GGEM, and NAM please. Hell, I'd take a blend of all of the models. Link to comment Share on other sites More sharing options...
wisconsinwx Posted November 19, 2015 Share Posted November 19, 2015 12Z Euro looks like it's actually too weak. It has the system rapidly weaken as it crosses into Illinois, and again crossing Lake MI, there are nothing on it support that happening, so outlier. Yes, too weak because it doesn't bring Hillsdale their blizzard. Link to comment Share on other sites More sharing options...
Stebo Posted November 19, 2015 Share Posted November 19, 2015 Not quite sure why the Euro went cheap on the QPF compared to last night's run, comparing the 500mb vorticity, it takes same path and evolution as last night's run. This could just be the Euro being the Euro with cold sector QPF, which it had issues last year. Link to comment Share on other sites More sharing options...
SchaumburgStormer Posted November 19, 2015 Share Posted November 19, 2015 I would gladly take a blend of the ECMWF, GGEM, and NAM please. Hell, I'd take a blend of all of the models. I agree 100%. Nice to be in the middle with plenty of wiggle room. Models in general agreement, with only some relatively minor track and strength issues to refine. Sure beat the 200 mile low placement swings from run to run that we saw with storms last season. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.