1. Eastern Ontario-Southern Quebec
10 June 2008
Eastern Ontario-Southern Quebec

2. Outline
Some of the fields associated with this case were shown yesterday using the Archive National Sector (s4) SPC Hourly Mesoscale Analysis page at...
Do a brief ( 10 minute ) work-up of your own using the data from this site up to 1500Z

3. Franktown Radar (XFT)
Set the replay end time to 1800Z and the loop length to 3 hours
Examine the developing line with all long-range and short-range SERF products
Where are the most intense cells? Which products are better for assessing this?
How does the nature of the Doppler output change with time?
What do you think of the Doppler output SE of the radar near the end of the loop? Discuss.

4. Villeroy Radar (WVY)
Set the replay end time to 2200Z and the loop length to 3 hours
Load the SERF and examine all longer-range products first
How does the structure of the line change with time? What small-scale features can you see?
How does the nature of the stratiform region change with time as the line passes the radar?
What radar artifact do you notice to the SSW of the radar?

5. Villeroy Radar (WVY) Next, examine all SERF short-range products
How does the structure of the line change with time? What small-scale features can you see? Are any of these correlated with velocity features?
Describe the changes in the Doppler pattern as the squall line passes this radar.
How fast are the strongest winds as the line passes the radar? Examine all levels. (Use “Pick a Point” to help you here.)
Make cross sections across the line and compare them to the classical conceptual model of a squall line.

6. Conceptual Model of Squall Line

7. WVY Cross Section

8. Chipman Radar (XNC)
Set the replay end time to 11 June 0300Z and the loop length to 3 hours
Examine all SERF products
Describe the evolution of the squall line as it moves into New Brunswick.
Do you expect much severe weather there?

9. Messages Mesocyclone signature near Franktown
supercell or not?
Beware of attenuation of precipitation behind and along the line
e.g. notice how the stratiform region intensifies once the squall line passes Villeroy
Beware of the effects of dome wetting
Local beam blockage to the SSW of Villeroy (WVY)

11. Storm Reports
Wind gusts of km/h measured at several sites in and around Montreal
Wind gusts of km/h in the evening in Maine
Trucks flipped on their side on a bridge spanning the St Lawrence
Videos of trucks on Champlain Bridge in Montreal:
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12. More Video of the Storm
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