IN THE CROSSHAIRS OF WINTER...
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After pouring over numerous models and teleconnections related to the long range forecast, early February in particular. I'm seeing some serious potential for cold and perhaps a bit of snow. Now I'm a fan of all kinds of weather, good or bad. That said, I've never hid my love for snow and extreme winter weather. I've always believed that if it was going to be cold, it might as well snow. Well, my wish for snow might not be realized, but the signals for significant cold are certainly there to see. Question is, how cold and when?
WHY MORE COLD?
This is the WPO (Western Pacific Oscillation) on Thursday's run of the EURO weeklies, a model that goes out 46 days. The AO is predominantly in a negative phase (strongly at times) through March 14th. That signifies a the presence of a strong ridge over the western Pacific that buckles the downstream flow allowing cold Canadian air access to the U.S. for extended periods of time.
The PNA (Pacific North America Oscillation) is also generally negative which implies some sort of broad trough over the Western or central U.S. Strong PNA's can be warm but with the extreme cold seeded in Canada and the WPO pushing it into the country, the Midwest should be situated in a spot where cold wins out. From time to time we may get close to the battle ground of warm and cold air which might spin up a snow system, probably moisture starved clippers. Working in conjunction the WPO and PNA can cause havoc. Unfortunately, it's impossible to see exactly where the warfare takes place at this distance but I see cold as a far bigger threat than snow.
The Climate Prediction Center has issued this outlook for much below normal temperatures in the day 3-7 period. This is just the tip of the iceberg.
What's happening with the MJO (Madden Julien Oscillation) may be the driving force that tips the scales in favor of cold. As you can see, both the EURO and GFS indicate a lengthy stay in phase 3 to start February. In the graphic below note that phase 3 is cold across the nation and precipitation in the Midwest is above normal. In its simplest form, It implies cold and snowy weather over my area. I buy the cold far more than the snow.
So far this January, we've observed the stretching of the polar vortex on several occasion resulting in bouts of sub-zero cold. Data indicates we should experience another version before or around February 8th. That's further evidence the first half of February is going to be wintry and perhaps bitterly cold.
Models are certainly seeing frigid air, especially the GFS. It's showing this for temperature departures over the 10 day period February 2-12th. My area comes in around 20 degrees below normal per day!
These are the departures the GFS indicates on February 10th. Many of these are in the range of 45 to 50 degrees below the typical norms
Should this verify (and let's hope it doesn't) it results in lows that look like this February 10th on the GFS. Many of these are in the range of 28 to 35 below zero...straight up. All-time record lows are right around 30 below so that gives you a good idea of the magnitude of what such a pattern could produce. Again, this is still tentative but the trend for nasty cold around this time frame has been consistent for several days.
Of course wind chills are extreme, shown in the 35 to 45 below category the 10th.
I rest my case regarding the cold.
WHAT ABOUT SNOW?
Last night I had a big discussion about phasing and how that would be a challenge that models would face with our next precipitation maker which doesn't arrive until Wednesday of next week. Phasing is the merger or bundling of energy between the polar and sub-tropical jet stream. Already models are vacillating with the GFS depicting less phasing until the system has progressed to the east of my area. I mentioned this possibility yesterday and it's significant because it means the storm is less amplified or intense. That in turn keeps the precipitation shield (in this case the snow band) further southeast. Total precipitation has gone from an inch near the Quad Cities to less than 1/4 inch. In just one model run, the GFS snow totals in the Quad Cites went from 12 to 3 inches. The question now becomes, does this southerly trend continue and this turn into a nothing burger, or does it hold steady or even shift back to the northwest? I don't see much of a chance this comes back north.
Had we experienced more phasing this could have been a heck of a storm for my area but that threat seems to be fading and it's the Ohio Valley and SE Great Lakes that get's pounded by the snow. The model inconsistency is all part of the game when forecasting snow at lengthy distances. We just don't have enough reliable data in the grids past 5-6 days to know for sure how energy is resolved. Another reason I also said yesterday I was not ready to jump on the snowy trends of 24 hours ago. I didn't even put up any snow projections. What's very disheartening is that we really could have used the moisture. So far January has produced just 0.45" in the Quad Cities, most of that with the New Year's day snow event.
Just to show you all the noise in the pattern, here's the latest 16 day GFS snowfall forecast vs the one 6 hours earlier. Guess which one I would have preferred.
The latest
6 hours earlier.
However this all plays out, the weekend looks very uneventful. In fact it now appears like we will remain dry through Tuesday of next week before any snow chances Wednesday. Temperatures will remain cold through the weekend before a brief thaw Monday and Tuesday that could see some readings near 40 in my southern counties which are pretty much void of snow. After what snow falls Wednesday, temperatures hit the skids again late next week. You can see the temperature trends for Cedar Rapids the next 8 days below.