The Raymond, AB tornado of April 18, 2004
At approximately 6:10 PM on the evening of April 18, 2004 (0010Z April 19 2004), a tornado touched down in a field near Raymond, AB. No damage was reported from this tornado.
Raymond is in the south end of the province, about 30 km southeast of Lethbridge.
The tornado was on the ground for approximately 20 minutes, and was photographed many times.
Dime to quarter sized (18 to 25 mm) hail was associated with this thunderstorm, falling at approximately the same time as the tornado was seen.
- Click here to see maps of where, exactly, the tornado touched down
- Pictures of the tornado and other associated pictures, courtesy of Bob Schefter
Meteorological setup note: the upper air fields are based on the 12-hour GEM prog; the surface-based fields are derived from a combination of actual surface conditions and the 12-hour GEM prog
- 250 mb - there was a reative lull in the jet level winds with 10 knots progged over the area; the base of a trough was approaching
- 500 mb - the 15 knot southwest wind at this level was advecting in cooler (-28° C) air, promoting destabilisation
- 700 mb - the 10 knot west wind at this level was also advecting in cooler (-8° C) air
- 850 mb - with the approach of a subtle trough and its associated thermal ridge, the stage was set for some upward motion
- Surface - with the approach of a subtle trough, surface convergence was likely
- Surface-based CAPE - there are fairly low values here, in the 200 J/kg range
- Helicity - very little 0-3 km helicity here - YQL (Lethbridge) is showing 12 m2/s2
- Energy-helicity index - with the relative lack of CAPE and helicity, this dimensionless parameter's values were nil
- 850 mb to 500 mb lapse rate - a strong area of destabilisation was approaching from the west, with values of up to 35° C
- Lifted index - weak instability is apparent here, with LI values in the -1° C range
- Lethbridge progged tephigram - the tephigram shows the fairly dry low levels and modest lapse rates, including a superadiabatic lapse rate from the surface to about 750 mb
- Lethbridge progged hodograph - this clearly shows very little low-level wind shear
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Last update to this page: April 30, 2004