THANKSGIVING WEEKEND SNOWSTORM....
Happy Thanksgiving everybody! Here's a joke for you. If April showers bring May flowers, what do May flowers bring?...Pilgrims!
Well Wednesday we made it above freezing, a bit of an accomplishment. Our 37 the first time we've been above 32 degrees since last Saturday morning. This continues the theme of cold weather that's dominated the month of November. Here in Cedar Rapids not one single day has been above normal. The average temperature of 30.9 through Wednesday makes this the 3rd coldest November on record with more chill to come, especially next week.
Preceding the next punch of frigid air is a winter storm which is expected to the hit the area. This is one of two pieces of energy that brings our quiet dry weather pattern of the past few days to an end. The first system Friday promises a chilly rain. It does its thing and departs allowing a short break Saturday. Then it's on to the main event Sunday which has the potential to significantly disrupt travel the last half of the holiday weekend.
Wednesday's focus was on the track and intensity of the storm. With the system just getting into the data rich grids of the west coast it will improve the models ability to initialize accurately. That's huge because when the model starts wrong, it's surely going to end wrong. It also eliminates some of the differences we've been seeing with regards to where the heavier snow falls.
So, with 3 days to go we are still in a time frame that's less than certain but rapidly approaching a window of much higher confidence. Here's what we know now.
A strong and amplifying short wave is getting set to dive into the Pacific Northwest. As it digs it will deepen and develop a closed 500mb circulation. Closed lows are associated with vigorous lift and that's what drives precipitation.
The 500mb jet Friday looks like this on the EURO. The energy over the state of Washington.
Sunday the energy has closed off and moved to southeast Iowa.
By this time a strong surface low is traversing Missouri on its way to Illinois. To the north snow and gusty winds will be a force over much of my area.
Precisely where the center of the cyclone tracks and how intense it becomes will determine where the sweet spot is for heavy snow. Speed will also be a factor. The slower the storm, the longer it has to produce accumulations. Here's what the GFS shows for totals as of Wednesday night.
The EURO solution has been the most consistent in terms of track. It;s also the most aggressiveness in terms of snow production. I favored its solution yesterday and I see no reason to back away from it tonight. Obviously there will be tweaks in the next 48 hours but overall I think it has the right idea. With that in mind here's what it shows for snowfall starting Sunday morning ending early Monday.
Here's a regional perspective of the EURO's snowfall output.
I'm not sure when it's coming but I think there's a very good chance winter storm watches will be issued by the NWS that include much of my area. If you are planning to travel Sunday in the central Midwest I would suggest keeping a close eye on forecasts keeping in mind the need to alter the timing of your travels.
Following the storm another healthy surge of cold air follows bringing temperatures to levels 15-20 degrees below normal. Depending on how much snow is on the ground, highs may not get out of the teens on Tuesday. For some perspective consider the fact that the average high January 15 is 27. Ouch! Lows will be even colder, perhaps below zero. The EURO has this for lows Wednesday morning.
In closing, my friend Steve Gottschalk in Lowden, Iowa makes long range forecasts based on the lunar cycle. I don't know his "top secret" formula but it seems to work. You can see for yourself below what he's expecting. Roll weather and have a wonderful Thanksgiving. I sincerely hope you have as much to be thankful for as me!
Here is the winter forecast I told you about.
Dec. 2nd - mild, rain/snow, windy
Dec. 7th - variable temps., rain/snow, windy
Dec. 9-10th - variable temps., rain/snow, windy
Dec. 12th - mild, rain/snow, windy
Dec. 15-16th - variable temps., rain/snow, windy
Dec. 22-24th - cold, snow, windy
Dec. 29th - mild, rain/snow, windy
Cold Spells: Dec. 17-21st, 24-25th, 30-31st.
Storms of 6" or more of snow would occur during the week of the New Moon (7-13th).
Jan. 5-6th - variable temps., rain/snow, windy
Jan. 8th - cold, snow, windy
Jan. 13-14th - variable temps., rain/snow, windy
Jan. 19-21st - cold, snow, windy
Jan. 25-27th - cold, snow, windy
Jan. 30-31st - cold, snow, windy
Cold Spells: Jan. 16-18th, 20th, 23rd, 26-31st
Storms of 6" or more of snow would occur during the week of the Last Quarter moon (1-4th & 27-31st).
Feb. 1-3rd - colder, snow,windy
Feb. 4-5th - warmer, rain/snow, windy
Feb. 9th - variable temps., windy
Feb. 12th - cold, snow, windy