All aboard the wave train

Currently a sharp warm front sitting across northern IL right now, just about south of I-80 at the moment with the sfc low at 997mb sitting in southwest IA.



As we continue in this active pattern there likes to be atleast 2 more potential big storms for us in the next 7-10 days with a possible small snow event tomorrow night. The models have been going back and forth with the strength and placement of this second wave coming out tomorrow. The problem is trying to figure out if and how much snow is associated with it. The past few runs of the NAM have been showing it further north solution bringing a sfc low from OK through southern MO and then into KY with snow displaced pretty far northwest of the low center and giving us a decent snowfall tomorrow night. The GFS has brought it north but not far enough to give us any real accumulating snow from it. LOT with their new afd monitoring this potential closely calling the NAM an outlier right now spitting out near 5" in some areas and this will have to be watched closely. The new 18z GFS pushes snow a bit further north tomorrow giving us maybe a few inches.

18z NAM for tomorrow night showing the snow over northern IL



The next one that looks to hit somewhere in the midwest thursday/friday is currently off the coast of BC out in the pacific and is forecasted to dive south into the pac NW and and continue south off the coast of california. The GFS/Euro are in pretty good agreement with this one and they both then turn it east and eject the wave out of AZ/NM and into the plains. The NAM is close to the other models regarding the placement of the southern stream wave at 84hrs but it has the northern stream system diving a bit further south. Although it doesn't look that impressive aloft, given the continuation of a strong baroclinic zone across the plains and into the midwest, this still has potential to be a strong low level cyclone. both models are bringing it down to around 996mb (12z GFS is a bit weaker but previous runs have been showing it stronger) and I think a stronger solution is a good possibility given the baro zone and it will have a good deal of moisture to work with. we dont need these really strong ULL's to get a big system, look at this current system, strong thermal gradient for the storm to ride along and we get a strongly forced frontogenesis band with heavy precipitaton for alot of areas in the midwest.

12z Euro showing the system late this coming week




This is like the book "And then there were none" haha but counting up, not down. The Euro/GFS/GEM all have been advertising another big system with a trof diving down into the west next weekend and kicking out into the plains going nuetral and eventally neg tilt looking quite impressive on the Euro. It is still far out to get into the details but the potential is there and with the system after system coming out, each one has to be looked at. Can't help but wonder what tornado season could be like if we stay active getting into april/may with abundant moisture.

H5 pattern showing a impressive negatively tilted s/w trof, 12z Euro



not to get ahead of ourselves but there are more storms after 216hr but no point in talking about those....yet.

The biggest snowstorm of this weather geek's life

I have been watching this thing for almost 10 days on the models and its finally happening...the biggest snowstorm of my life is bearing down on northern IL as I write this 5" is down in the past 90 mins in Ottawa, OK. That is only a sign of things to come up this way as we head into the evening and overnight hours. In order for us to have got this storm we needed the northern stream wave to phase with an intense pacific cyclone that came onshore over southern california sunday and moved over the four corners region during the day yesterday and is now currently over the southern plains.

you can see it here on the 24hr WV loop..you can see it already has a textbook look to it with the moisture available really starting to show itself. Everything about this storm is epic. This is seriously the most excited and giddy I have ever been over a single weather event. The ONLY negative about this storm is the speed, and I wouldn't even call that a negative, just me wanting it to last longer.

http://climate.cod.edu/loops/US-WV24.loop.html



The moisture with this thing is absolutely insane coming off the gulf and feeding into this system thanks to a 850mb jet over 80kts! That is a very rare! This is going to make the freezing rain potential even worse. Your going to have the warm air around 850mb running up and over the cold air and the surface creating an ice storm in parts of IN/OH.




]I'm not going to make this thing super long since the storm is already going but here you can see the radar and how massive and epic it already looks..

http://radar.weather.gov/Conus/full_loop.php

Another story is going to the strong winds with this storm as it begins to wrap up later this afternoon and into the overnight hours. As you can see on the sounding we have 65kt just off the deck that are going to try their hardest to mix down later on. We will have 50mph gusts up here coupled with very intense snowfall rates possibly nearing 3"/hr...here is a forecasting sounding showing the very strong winds..




What is going to be the coolest thing about this storm is the good possibililty of thundersnow occuring during the evening and overnight hours. Here is a section of the morning AFD from the chicago office (LOT)

PART TWO OF THE STORM WILL BE WITH INTENSIFYING TROWAL/DEFORMATION ZONE TONIGHT. UPWARD VERTICAL VELOCITIES ARE FORECAST TO BE ALMOST OFF THE CHARTS TONIGHT AS UPPER TROUGH CLOSES OFF INTO A NEGATIVELY TILTED CLOSED/COMPACT MID LEVEL LOW AS IT LIFTS NORTHEAST TOWARD SOUTHERN LAKE MICHIGAN BY EARLY WEDNESDAY MORNING. ALL INDICATIONS ARE THAT VERY INTENSE SNOWFALL WILL DEVELOP WITHIN THE DEFORMATION BAND WITH TREMENDOUSLY STRONG UPPER LEVEL DIFLUENCE AND DIVERGENCE AHEAD OF THE DEEPENING CYCLONE. FORECAST SOUNDINGS SUGGEST THAT VERY STEEP MID LEVEL LAPSE (NEARING 8C/KM) ASSOCIATED WITH THE VERY COLD TEMPS ALOFT WILL PROVIDE FOR SUFFICIENT INSTABILITY FOR EMBEDDED THUNDERSTORMS TO DEVELOP WITHIN THE TROWAL...LEADING TO LOCALLY ENHANCED SNOWFALL TOTALS. IN FACT...SEVERAL MODELS SUGGEST THAT MUCAPES OF 100-200 J/KG WILL DEVELOP WHICH MEANS WE COULD ACTUALLY SEE UPRIGHT CONVECTION DEVELOP.

as for amounts...I really think some places are going to have a shot at 24" with this thing trending a bit more northwest and stronger...so right now I'm going to go with 16-24" given the trends in the hi res models and current radar, sat, etc.

HRRR...

5pm, intense snow moving into northern IL.



can probably bet on some thundersnow in this..11pm



RUC..

showing 20"+..




As this sfc low continues to track northeast later this afternoon/evening the snow should start here around 2pm or so and conditions will begin to deteriorate very quickly and could make the rush hour very bad.

I could post a 100 images about this storm..

9z SREF 12hr mean snowfall amounts....15" in 12hrs..other images are also showing 10-12" in 6hrs and 6" in 3hr..this is going to be soooo epic!



All in all this looks like it "could" make a run at the record snow total from 1967 where 23.1" of snow fell..

one more image just put out my SPC

Its beginning..



Oh and by the way...there is a tornado watch out in the south in LA/MS.



Matt