To Snow, or Not to Snow

NCEP GFS 6 Hourly Precipitation QPF

gfs_pr6_slp_t850_mw_16If you live south of interstate 80, you might have woken up to some snow falling this morning. The snow is now done, but some locations did receive a light dusting just enough to make things slick earlier this afternoon. Things will now be quiet for a few days before our next system moves though Sunday night through Tuesday. This low will move across northern Iowa, and will bring a chance for rain, rain/snow mix and eventually all snow.

gfs_6hr_snow_acc_conus_22Most of this precipitation will start off as rain across western Iowa Sunday night and will overspread the state on Monday. Temperatures will be warm enough during the day Monday that all precipitation will fall as rain. Eventually rain will then transition over to snow across northern Iowa Monday night and across the rest of the state on Tuesday. This system does bring accumulating snow across northern Iowa, with lower amounts to the south. Right now, it is too far out to determine snowfall totals, but snowfall accumulations will be possible across northern Iowa by Tuesday morning.

gfs_ptype_slp_conus_28As this system moves off to the northeast, it will begin to interact with a secondary low. This phasing will take place on Christmas and will create a impressive storm system over the northeast. The 18z GFS has a pressure of 968mb. This is very low for a low pressure system over land. This strong low over the northeast will have an impact on our weather back here at home on Christmas eve. Santa is going to have a strong wind to contend with when delivering gifts. As the pressure gradient increases, so will our winds. Christmas eve and Christmas day will be dry with seasonal temperatures, before our next system moves in the day after Christmas.

gfs_ptype_slp_conus_31This next system that will move through the Midwest on the 26th, has been all over the place as of late, and will continue to shift track as it is still a week away. Because of this inconsistency, we will not go into great detail about this system. The latest 18z GFS has the track of this low moving across northern Missouri. This places a band of moderate snowfall over central Iowa by the morning of the 26th.

cmc_precip_mslp_conus_33The 12Z GEM is also taking a similar track with this system, with the only difference that it is more bullish with intensity. The 12Z ECMWF has the track of this low further to the south, where the majority of this snow would miss Iowa. This was a change this morning as the 00z ECMWF had the low taking the same track the GFS and GEM are showing. There is still a lot of time for things to change, but if you are traveling across the Midwest on the 26th, you will want to keep checking back on the very latest.

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:

(2) Comments

  1. What would the ice potential be four SE. Iowa from December 22 through January 1?I will be traveling with my family in from Cleveland Ohio to Mount Pleasant Iowa that week and are very concerned about the weather conditions. Thanks!

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