Forecast: Looking Ahead Seven Days


     [January 15th. 2018 – 1:30 A.M.] Good snowy morning everyone. We are currently seeing a pretty decent clipper system pivot through the region this evening and overnight. Snowfall totals of 1-3″ are common across the Upper Midwest with amounts exceeding 4″ in portions of southwest Wisconsin. This weather maker should pivot on out of the region by mid day bringing another shot of cold, bitterly Arctic air down. Winter just wouldn’t be the same without this type of weather every so often am I right?  After this system passes, what kind of weather can we expect to see?  The good news is we’ll return to sunny conditions Tuesday, the not so great news is the air will still be frigid. Seasonal temperatures aren’t the worst type of chill we can see around here this time of year, but it’s a far cry from the 60’s we observed just a few short days ago.  Let’s take a look ahead at some interesting weather headed this direction.

     NOAA’s Weather Prediction Center issued their 8-14 day outlook earlier and highlights much of the eastern sections with an above normal chance of being warmer and wetter than normal. That’s not saying we are going to be 70% wetter than normal, it’s saying there is an XX amount percentage that we can see above normal precipitation and/or temperatures for that period.  Namely what I am focusing on is the potential for a large storm system to traverse the mid section of the country somewhere in the 20th to 22nd time frame. I have a strong suspicious this particular outlook is reflective of that storm system. It is way too soon to predict the exact type of weather we can expect, but I think the opening image on this article does a good job summing it up. There will be the potential for snow, rain, wind, and even thunderstorms somewhere across the Mississippi River Valley during the next seven days. Beyond that this is still a vast spread in the models, but at least some suggest a continued mild regime over portions of the Midwest. 

GFS - H5
GEFS - H5
GEFS - H5 ZOOMED

     We’re going to take a gander at the GFS and it’s ensembles from earlier today. The GFS has not performed well overall with many systems over the past several months, but I have noticed the last couple bigger systems it has performed reasonably well. I think it’s fair to look at at this range and it paints a pretty wide spectrum of events here across the Land of Lincoln. Picking which one will ultimately be correct is a game of Russian Roulette that I don’t feel like participating in at this juncture. My business and my page are doing fairly well, so I don’t need to post the hype graphics as a last effort to save my dying career…… or I don’t work for the mainstream media. Take your pick there! Nearly all solutions from the operational model to the ensembles show a storm system developing and riding diagonally across the mid section. There has been some run to run consistency with this and the upper air pattern is one that would support a deep area of low pressure being born and maturing. 

     I know everyone is waiting to see what the Euro has to say. The Euro is the noobs go to model to predict the weather and the seasoned forecaster’s best friend to verify their own findings with. More times than not the Euro is tops in coming closest to sniffing out an active pattern and/or storm system and quickest in discerning as well. No one weather model is the end all be all, but the Euro seems to perform fairly well comparatively speaking. 

     With all of that being said, we see some decent agreement with regard to developing a system. At this range I only really look at the H5 plots since I want to see a nice deep trof. Many larger systems are birthed within these trofs. I have been waiting for our “big dog” to appear in the models and this period of time has as good a chance as any. Not only is it being represented by the global, the Euro, and the Canadian models (shown below), it is also in a period that favors these system climatologically speaking. If you recall some of our largest blizzards have occurred right at the end of January into early February. By no means am I saying we will be getting a blizzard, but it bares watching. Spring is prime time for tornadoes across our state, the middle to end of winter is prime time for significant snow storms.  We know this based on climatology and history.

GEFS - MJO

One aspect of forecasting that interests me has always been the MJO or Madden Julien Oscillation. The Madden-Julian Oscillation (MJO) is the major fluctuation in tropical weather on weekly to monthly timescales. The MJO can be characterized as an eastward moving ‘pulse’ of cloud and rainfall near the equator that typically recurs every 30 to 60 days. Teleconnections as a whole are essential pieces to the atmospheric puzzle. While they are some times difficult to process, being able to recognize shifts with a positive to a negative phase (vice versa) can provide crucial clues to local weather.  Below are where we currently stand and some analogs to show some of the deviations from normal we could see in temperature an precipitation. 

     Another teleconnection of particular interest to the region is the PNA or Pacific/North American teleconnection pattern. These patterns give a clue as to how local weather may unfold. The positive phase of the PNA pattern features above-average heights in the vicinity of Hawaii and over the intermountain region of North America, and below-average heights located south of the Aleutian Islands and over the southeastern United States. The PNA pattern is associated with strong fluctuations in the strength and location of the East Asian jet stream. The positive phase is associated with an enhanced East Asian jet stream and with an eastward shift in the jet exit region toward the western United States. The negative phase is associated with a westward retraction of that jet stream toward eastern Asia, blocking activity over the high latitudes of the North pacific, and a strong split-flow configuration over the central North Pacific.

     Now that I have totally lost your interest, let’s refocus and continue to talk about what to expect over the next seven days. Teleconnections, mid-long range operational models, and ensembles all point to an active weather pattern developing by next weekend and beyond. While the signal is there for inclement weather to occur, specifics are futile at this point. If you are planning an event or going out of town around late week through the weekend, you’re going to want to keep an eye out for later forecasts. Climatologically speaking, there could be a winter storm threat across the north and even some severe weather in the south. I will have another update in a few days. 

 

DNEAL 

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About Danny Neal

Danny is a storm chaser from the southside of Chicago and has been chasing since 1998. He has over 100 tornadoes documented as well as numerous other extreme weather events. He routinely teaches and trains others about severe and unusual weather and is considered a great resource for Northern Illinois. As a partner with NOAA, he spends most of his time assisting the National Weather Service Chicago during severe weather operations