Kansas City Winter Weather Climate Review
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Transcript of Kansas City Winter Weather Climate Review
Kansas City Winter Weather Climate Review
October 28, 2008
Created by: Mike JulyPresented by: Matthew Dux
Layout of Presentation
Review Kansas City Snow Climatology
Review Synoptic Patterns Conducive to Heavy Snow
Review Freezing Rain Climatology
There have been 1835 measurable snow events (roughly 15/yr) at the official Kansas City reporting site since 1888. Of those, only 144 events (7.8% or approximately once per season) where 4 or more inches of snow fell and only 57 events (3.1% or once every 2 seasons) where 6 or more inches of snow fell on a calendar day.
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Oct Nov Dec Jan Feb Mar Apr
24 hr KC Snowfall (1888 thru Sep 2008)
>= 0.1 >= 2.0 >= 4.0 >= 6.0
•1835 Snow Events• 15 /year
•144 Events ~ >4”snow
• ~1 /season
•57 Events ~ >6” snow
• ~1 /2 seasons1634 Snow Events < 4”
30 Year Snow Climatology (1971-2000) 30 Year Snow Climatology (1971-2000)
Four Primary Patterns Favorable for Heavy Snowfall in the EAX CWA Four Primary Patterns Favorable for Heavy Snowfall in the EAX CWA
Northwest Flow System or “Clipper” Southwest Low Progressive Short Wave Trough Deepening Low
Northwest Flow System or “Clipper”
Four Primary Patterns Favorable for Heavy Snowfall in the EAX CWA
Southwest Low
Four Primary Patterns Favorable for Heavy Snowfall in the EAX CWA
Progressive Short Wave Trough
Four Primary Patterns Favorable for Heavy Snowfall in the EAX CWA
Four Primary Patterns Favorable for Heavy Snowfall in the EAX CWADeepening Low
Freezing Rain/Freezing Precipitation Climatology
30 yr average (1971-2000) – 3.2 events/yr 30 yr average (1948-1977) – 3.2 events/yr 53 yr average (1948-2000) – 3.2 events/yr
Seasonal Frequency 1948-2000
Dec-Feb72%
Rest of the Season
28%
FZRA events peak inDecember/January
Kansas City
December, January andFebruary have an equaldistribution of FZRAevents
Seasonal Frequency 1971-2000
Dec-Feb74%
Rest of the Season
26%
92% chance FZRA will occur in during the cold season (Nov-Mar). 83% chance FZRA will occur on 1 to 5 days per cold season. 58% chance FZRA will occur on 2 to 4 days (annual avg 3.2/cold season)
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Seasons
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# of FZRA Events
KC Seasonal Distribution (1948-2000)
(1971-2000) – 3.2 days/yr (1948-1977) – 3.2 days/yr (not shown) (1948-2000) – 3.2 days/yr
Kansas City Averages Kansas City Averages
Annual Mean Freezing Precipitation Days (FZRA & FZDZ)
Annual Mean Freezing Precipitation Days (FZRA & FZDZ)
Monthly Frequency of FZRA/FZDZ Monthly Frequency of FZRA/FZDZ
Primary Weather Patterns Associated with Freezing PrecipitationPrimary Weather Patterns Associated with Freezing Precipitation
Studies by Bennett (1958), Changnon (2003)and Rauber, et al (2001) came to very similarconclusions………
1) Arctic Fronts account for 42%2) Warm Front / Occlusion – 19%3) Cyclone/Anticyclone – 26%
• Pattern 3 most severe due to heavy icing plus high winds.• Area of FZRA/FZDZ is typically narrow and just north of 0C surface isotherm.
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Summary/Other Important ItemsFZDZ occurs much more frequently than FZRA.
In KC freezing rain peaks in Dec/Jan.
Three primary weather patterns account for the vast majority of all freezing precipitation in Kansas City (possibly as high as 90%).
Between 1 and 5 freezing rain events per cold season with an annual average of 3.2/season.
Around 80% of all FZRA events occur with 2m temperatures within a tight range (28-32F) whereas the vast majority of FZDZ events occur within a much broader range (21-32F).
The Freezing Precipitation Frequency graphics from NCDC look suspect….especially for December.