1. BFB
Winter Storm Tracks

2. Where lows are born Leeward side of mountains Canada
Specifically the Rockies in the US
Canada
Specifically Alberta
Usually called an Alberta Clipper
Sometimes referred to as Saskatchewan Screamers and Manitoba Maulers

3. Where lows are born cont.
Between the east coast and the Appalachians where cold air damming is present
In the Gulf of Mexico
All of these lows can take different, or similar tracks depending on the upper air forcing in place

4. Where lows live
Alberta clippers tend to take a track along the northern US across the Great Lakes
Sometimes they can dip south and become stronger Nor’easters
Are usually dryer, colder systems than others that form in the gulf or along the coast
This can make the snow to water ration higher (more like we would see with lake-effect)
They can also provide favorable winds for lake-effect

6. Where lows live cont. Colorado lows
Form from descending air moving over the Rockies
Starts as moist pacific air which becomes condensed out before the mountains
Then descends on the east side of the Rockies, typically forming a low in the Colorado area
Movement of low depends on the upper air pattern

7. Where lows live cont. Gulf lows
Form in the Gulf, or re-intensify already existing lows
The Gulf can add a lot of moisture and energy to lows
Can cause rapid intensification for lows

8. Where lows live cont. East coast lows
Cold air damming creates a baroclinic zone along the coast
Placement of high pressure is key to creating the cold air dam
Lows can form along this zone of temperature difference

9. Where lows live cont. Typical Nor’easter Miller type A Miller type B
Typically start in the Gulf and ride up the east coast
Miller type B
Usually have a low moving in the Great Lakes region west of the Appalachians
Secondary low forms along the east coast southeast of the primary low
If primary low remains too strong, secondary low won’t be as strong

10. Where lows live cont. Typically have very low snow to water ratio
Makes physically heavy snow
Typical ratio of 10:1

12. Where highs live High pressure is as important as low
If you don’t have a strong high, you won’t form a strong low
In the middle of winter, high pressure brings continental polar air into the US
This temperature difference provides forcing for quick intensification of lows (bombs)

13. Jet streak coupling When two jets get together, rising motion ensues
See next slide