While looking through the Accuweather.com forums it dawned on me that I wanted to see how well I did on the January 7th call. Without further hesitation, here we go…
Bering Sea Section of 13DEC14 Long Range Discussion…
The Bering Sea shows a strong storm developing on the 15th. We then see a gradual warming trend until a spike in temperatures prior to an even stronger storm on the 18th of December. This translates to a strong storm around January 7th here. My personal thoughts are that this will provide areas of the North Central Plains with a significant snowstorm and well above normal temperatures for Central Missouri prior to it. Northwest flow follows with cold air until the 10th.
Typhoon Rule Section of 28DEC14 Long Range Discussion…
The typhoon rule has a system impacting Japan today with slight ridging before another system on the 30th. A potent trough takes over and more energy comes from the Northwest on New Year’s Day. Then, zonal flow takes over before a slow ridging and storm on the 5th of January. The trough that follows hangs around to at least the 9th of January. For Central Missouri, this means a storm on January 4th with slight warm up before another storm on the 6th when the cold shot hits and a clipper comes down the pipe on January 7th. A gradual warm up ensues until the next storm on January 12th with more cold to follow until at least January 16th.
From the St. Louis National Weather Service AFD, Area Forecast Discussion…note the similarities?
Attention for tonight will turn to the deformation zone which will
slide through the northwest third of the CWFA. Mid/upper level
forcing mechanisms do not look overly impressive as shortwave
dampens as it heads northeastward. Precipitation amounts not
surprisingly do not look too high given the lack of strong upper
air forcing for ascent with amounts generally under a quarter of an
inch. Thermal profiles suggest precipitation starting as rain within
the precip shield tonight before slowly transitioning to snow as
a) the BL cools sufficiently and b) midlevels re-saturate to
reintroduce the presence of ice crystals. All in all…appears to be
roughly a ~3 hour window for possible snow accumulations. Tack on
poor antecedant conditions…i.e. a warm/wet ground…snowfall amounts
should be light. Highest amounts should still be in Knox County topping
out around an inch.
A secondary shortwave will follow quickly on the heels of its
predecessor. Left mention of flurries into the day on Sunday due to
the forcing from this shortwave and broad cyclonic flow aloft.
Temperatures will be quite a bit cooler on Sunday than today with
non-diurnal temperatures continuing for a large portion of the area.
(Sunday Night – Friday)
Rest of the valid forecast period still appears dry. Mid/upper level
flow will amplify across the CONUS with a ridge along the west coast
and a broad trough across the eastern two-thirds of the country.
First in what will likely be a series of upper-level disturbances will
transverse the Upper Midwest and slide into the mid-Atlantic region
on Monday night. Maintained sch PoPs for far northeastern sections of
the area which may get clipped by clipper. Most of area still looks dry
however there is still quite a bit of uncertainty in eventual track.
Pattern looks even further amplified heading into midweek with a
much stronger shot of arctic air in store. Certainly looks by far and
away the coldest air we have seen thus far this mild winter season.
Look for temperatures some 20+ degrees below normal day/night Wed/Thu.
Lows will likely even dip below zero over portions of the area Thu
morning…which is quite impressive given the high likelihood of no
snow cover…just goes to show how truly impressive the air mass is.
One note regarding the last paragraph, the fact that we have no snow cover will allow for a gradual rebound of temperatures as stated in my earlier forecast discussions.
Here are some graphics…
Day 3 Snowfall ≥4″ probabilities…my call on the North Central Plains was off as the clipper doesn’t get it’s moxie going until the Northern Midwest.
Day 3 CONUS map
The WPC 500mb charts for Days 3-7…focuses on the NW flow and it relaxes as we approach the 9th.