Hawkeye

Yeah, the euro is pretty darn consistent. http://wx.graphics/models/ecmwf/2017121812/mw/ecmwf_acc_snow_mw_102.png

12z UK is now a whiff for Minneapolis. Unfortunately, this run delays the organization of the southern wave, so there's very little precip until it's past Iowa. http://wx.graphics/models/ukmet/2017121812/conus/ukmet_mslp_conus_108.png http://wx.graphics/models/ukmet/2017121812/conus/ukmet_acc_precip_conus_120.png

There's an awesome, region-wide fantasy-range storm on the GFS tonight. Too bad it's likely to be a one-run wonder.

So, the GFS only briefly dug the arctic trough more into the west, leading to a Christmas snow event, but has now gone right back to digging the arctic blast right down into Iowa. That's great for bitter cold, but lousy for precip.

Yeah, this run digs the upper trough farther west, so we get some precip enhancement on the east edge. The first system sweeps the surface front well southeast of the region, so there's no deep moisture available, but it has a long-duration light event. Models keep shifting around the placement of the arctic trough digging into the US. One run it digs over the lakes, then it's over us, then west, then back east, etc.

The UK holds all the energy back for one low tracking south of Chicago Friday. The Euro ejects a weaker, less moist, low across southeast Iowa Thursday night, leaving the next piece of energy to simply enhance thunderstorms along the front.

Just a huge change from the UK this morning. Last run took a strong low up through central Iowa. The new run has a strengthening low tracking from St. Louis to Toledo, with heavy defo zone precip from northern Missouri through Chicago to Lake Huron. http://wx.graphics/models/ukmet/ukmet.php

http://wx.graphics/models/ecmwf/2017121700/mw/ecmwf_acc_snow_mw_150.png

Here's the wx.graphics UK page. You can see the storm is beginning to blow up at 144 hrs as it crosses central Iowa. The low is 989 mb and it's just beginning to make the connection to a deep moisture feed. http://wx.graphics/models/ukmet/ukmet.php

Probably just far nw Iowa and points north and west.

144 hr UK precip map http://wx.graphics/models/ukmet/2017121700/conus/ukmet_6hr_precip_conus_144.png

That's quite a bowling ball PV dropping into the upper midwest following the late-week system. Yikes. High temps well below zero. Of course, there will probably be little if any snow cover to insulate the ground/garden. I should probably lift my tarps and dump more leaves on the tender plants.

The nice, sharp upper trough digs into the central Rockies, but as it ejects eastward the northern stream comes in and stretches it apart, so it's just rather feeble overall.

We've been overperforming by a few degrees recently, and today is no different. We just hit 50. I went to Cedar Lake for a little birding walk. The lake is 95+% iced over, but there was still a flock of 1000+ Canada geese and mallards. I actually felt a bit warm in my winter coat because the wind was calm.

And the sharp snow gradient from northern Iowa to southern Iowa continues into another winter. If all I'm going to get from this is some light rain followed by a half inch of slop at the end, forget it. Keep the entire thing north.

There are still quite a few north whiffs on the GEFS posted above. The 12z UK is pretty bad, too. It holds the northern stream back, allowing for a much more nw track. http://img.meteocentre.com/models/ukmet_amer_12/GZ_D5_PN_144_0000.gif

It's certainly nice to finally see a snow system consistently showing up on the models. At this point, it's nothing too big for Iowa, but it's something. One thing I don't like, however, is the temperature. Models suggest above freezing, falling to the low 30s, perhaps with a bit of rain to start. I hate having to deal with an initial layer of slop.

The system next Thu/Fri might be it for the year. Following that system, the GFS/Euro are locking us right back into the cold, dry northwest flow while the moisture is suppressed to the southern states, perhaps up into the Ohio Valley.

The lead system that tracks across the south sweeps away all the deep moisture, so there's not much left for the upper midwest system.

The active, snowy pattern for the plains/midwest Chrismas week and beyond sure disappeared in a hurry. The last few runs of the GFS show little if any snow around here through the end of the year.

Models are pretty erratic later in the period. Here is what JB had to say late this evening... "GFS all over the place. Goes from Day 10 PV in lakes to Big ridge in east. Feedback fairy directs stream into the west. Next run may flip again, MJO and EPO argue eastward push though".

JB has been saying that a western trough being depicted on some model runs just doesn't make sense given the state of the EPO, MJO, etc.

Yes, the EPS is showing a much better pattern beyond day 10, similar to the GFS. Here is the latest EPS city chart for Cedar Rapids. I love this new feature added by Ryan Maue. http://wx.graphics/models/ecmwf/2017121212/city/KCID_2017121212_forecast_EPS_precip_360.png

There's a report of 3.2 inches of snow, in only a few hours, just nnw of Mt. Carroll, IL. A small pocket of huge flakes parked over them this afternoon.

As I suspected might be the case, once the initial burst of large flakes subsided, the snow rate was not able to counteract the warm surface/ground temp(air temp never dropped below 35). We finished with only a spotty slushy dusting. So, our season continues to be without any measurable snow.