Up & Down

NCEP GFS 6 Hourly Accumulated Snowfall 12/18

Iowa Highs Friday

A much deserved warm up is on the way this weekend after enduring a very cold November. Temperatures will be warming up into the 50’s as early as Friday and will continue to warm up through the weekend. However, a change in the weather pattern on Sunday will be changing up our weather.

GFS Jet StreamTo start off, by Saturday, the ridge which will be bringing us the dry and warm weather will be right over the state. However, off to the east, you can see a trough is digging into the southwest and this is what will be changing our weather up by Sunday afternoon as it moves through the state.


A low will be moving across Missouri on Sunday, and this will allow moisture to be pulled into the state. For snow lovers, we do not have good news for you. Temperatures are going to be above freezing that the majority of the precipitation will fall as rain. However, as the system pulls off to the east, cold air will be working in on the backside, that remaining precipitation may fall as a rain/snow mix. There does appear to be a good amount of moisture with this system so decent rainfall amounts will come out of this system.

GFS Dew PointsAnother thing that we will be dealing with by the weekend is the fog. Dew points this weekend will be in the 40’s which will provide areas of dense fog. As we get closer to this weekend, would likely see areas of dense fog advisories issued. If you will be traveling this weekend, make sure to take this into account, as reduced visibilities will be likely.

ensplume_fullA few days ago we showed the the MJO forecast. This gives us an idea of what temperatures will be doing over the extended forecast, which is what many of you are wanting to know. Currently we are in phase 6 of the MJO, however, it is forecasted to go into phase 7 by the end of the weekend.

PhasesFrom the graphic above, you can see in phase 7 of the MJO, that below average temperatures will be likely. This is good news for us snow lovers as colder temperatures mean snow instead of rain like we will be seeing this weekend.

gfs_6hr_snow_acc_conus_25Even though we will be on the cold end of the spectrum, the flip side is now we need the precipitation. Looking at the long range GFS forecast, there aren’t a whole lot of storms to bring us this precipitation. The snow that is showing up across Kansas and Nebraska is from Sunday’s storm as the GFS is wrapping in enough cold air that they should see more snow than rain. However, as you can see above, through December 17th at 6pm, no snow will be piling up here in the state. That still leaves us with one more week to get some snow. There are some signs that we may possibly get a shot at another system around December 21st and 22nd, but right now that is too far out to have high confidence in. If you are wanting a white Christmas, keeping doing your snow dance! Until then, enjoy the December thaw this weekend.

Zach Sharpe

My name is Zach Sharpe. I am the president and forecaster for the Iowa Storm Chasing Network. You can find me on Twitter @Stormchaserzach and on Facebook at: https://www.facebook.com/stormchaserzach/

(2) Comments

  1. Love everything about the weather!!! Interested in knowing what the weather will do traveling down to Springfield,MO around Christmas from our home here in SW Iowa around Massena? Have a son in Mo who may meet us near KC around that time frame!! Please help as we do not have smart phones to check this!

Leave a Reply

%d bloggers like this: