Shift in weather long-range 

Posted: 8:09 am Monday, November 27th, 2017

By Kirk Mellish

Chilly mornings and seasonably mild afternoons for classic autumn weather has been the recent pattern. We trend back warmer than normal this week into next weekend, but by the following weekend the models agree on a shift to below-normal.

It has been mostly dry the past couple months and not much precip is expected the next 5-10 days.

The “warm” upper-level ridge gets replaced by a an upper level trough and the temperature pattern follows the shift aloft at the surface.

The month of November so far:

MonthTDeptUSMonthPDeptUS

p168igefs_z500_noram_27

eps_z500a_5d_noram_61gefs_z500_noram_51gefs_z500_noram_65gefs_t2anom_16_noram_1eps_t850a_noram_43eps_t850a_noram_51

eps_t850a_noram_61

WxBell

TOTAL SNOWFALL OVER THE 32-46 DAY PERIOD:

eps_sno_768_conus_129

gefs_snow_mean_east_65

These maps have a record of over-doing snowfall accumulation, I do NOT currently expect snow below I-40 in our region in this time frame.

Analog years to similar pattern shifts in the past show the pattern tries to take hold for the month as a whole, but I am not so sure:

Screen Shot 2017-11-27 at 9.34.07 AM

The “memory” of weather from one month to the next is similar on the national level as this chart for Illinois. The higher the bar the more likely that the month following will be like the month before:

temp_persist

KRYY_2017112800_eps_min_max_15KRYY_2017112806_min_max_16

Follow me on Twitter @MellishMeterWSB.

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