56
Green Events
Green Events
Aug 3. 2006Date Propagation
SpeedLightning Stripe Length (degrees)
Squall line length
Aug. 3 15 m/s 35 deg. 770 km
Additional Comments: AEJ with 25 m/s jet core at 700 hPa extending from 0-23W. MCS and ITF cyclone appear to develop in phase. Low-level theta e advection on S side of ITF cyclone appears to help MCS.
925 Vorticity (2x10-5s-1, red contours) and 700 Streamfunction (x106m2s-1, black contours)
700 PV (0.1 PVU, shaded) and Streamfunction (x106m2s-1, black contours)
925 θv (K, shaded), Vorticity (>2.5x10-5s-1, red contours), and Streamfunction (x106m2s-1, black contours)
700 Streamfunction (x106m2s-1, black contours) and Windspeed (ms-1, shaded)
925 θe (K, shaded), Vorticity (>2.5x10-5s-1, red contours), and Streamfunction (x106m2s-1, black contours)
Aug 6. 2006Date Propagation
SpeedLightning Stripe Length (degrees)
Squall line length
Aug. 6 10 m/s 31 deg. 530 km
Additional Comments: Begins at entrance of AEJ, 700 hPa easterlies are broken and perturbed by convection in AMMA reanalysis. Develops on the eastern edge of a southerly surge. Low-level flow is weak with theta e values that aren’t particularly high. A weak vortex along the ITF was moving into this moist environment. Its weakness may be related to the lack of any AEW.
925 Vorticity (2x10-5s-1, red contours) and 700 Streamfunction (x106m2s-1, black contours)
700 PV (0.1 PVU, shaded) and Streamfunction (x106m2s-1, black contours)
925 θv (K, shaded), Vorticity (>2.5x10-5s-1, red contours), and Streamfunction (x106m2s-1, black contours)
700 Streamfunction (x106m2s-1, black contours) and Windspeed (ms-1, shaded)
925 θe (K, shaded), Vorticity (>2.5x10-5s-1, red contours), and Streamfunction (x106m2s-1, black contours)
Aug 22. 2006Date Propagation
SpeedLightning Stripe Length (degrees)
Squall line length
Aug. 22 14 m/s 21 deg. 1040 km
Additional Comments: Some very intense convection developed along the Niger / Nigeria border at 8/21 2100Z. This initiation occurred in the NW sector of an AEW trough. Large increase in 700 hPa jet on eastern side of the convective system from almost nothing to a large core of 20 m/s. A strong ITF cyclone well to the NW over NW Mali was advecting large amounts of high theta e from the west. This convective event was the developing stage of a very intense and very large AEW which developed over the next two days. Part of the previously mentioned strong westerly flow appears to be tied to a Kelvin wave of moderate intensity which was propagating over the region at this time. Trough digging in over West Africa in the days prior (tied to Kelvin wave and or ITF cyclone?).
This is a really interesting event!
925 Vorticity (2x10-5s-1, red contours) and 700 Streamfunction (x106m2s-1, black contours)
700 PV (0.1 PVU, shaded) and Streamfunction (x106m2s-1, black contours)
925 θv (K, shaded), Vorticity (>2.5x10-5s-1, red contours), and Streamfunction (x106m2s-1, black contours)
700 Streamfunction (x106m2s-1, black contours) and Windspeed (ms-1, shaded)
Aug 28. 2006Date Propagation
SpeedLightning Stripe Length (degrees)
Squall line length
Aug. 28 17 m/s 27 deg. 1010 km
Additional Comments: Although the AEJ was fairly zonal and strong the low-level flow was fairly chaotic a number of vortices along the ITF.
925 Vorticity (2x10-5s-1, red contours) and 700 Streamfunction (x106m2s-1, black contours)
700 PV (0.1 PVU, shaded) and Streamfunction (x106m2s-1, black contours)
925 θv (K, shaded), Vorticity (>2.5x10-5s-1, red contours), and Streamfunction (x106m2s-1, black contours)
700 Streamfunction (x106m2s-1, black contours) and Windspeed (ms-1, shaded)
Aug 30. 2006Date Propagation
SpeedLightning Stripe Length (degrees)
Squall line length
Aug. 30 23 m/s 32deg. 1430 km
Additional Comments: Develops in NW sector of trough in an environment with an intense (20-30 m/s) AEJ which extended from the Ethiopian Highlands all the way to the East Atlantic. Possibly some Kelvin wave activity. This convective system helped to build an AEW of moderate intensity with clear sinusoidal perturbation of the PV strip.
925 Vorticity (2x10-5s-1, red contours) and 700 Streamfunction (x106m2s-1, black contours)
700 PV (0.1 PVU, shaded) and Streamfunction (x106m2s-1, black contours)
925 θv (K, shaded), Vorticity (>2.5x10-5s-1, red contours), and Streamfunction (x106m2s-1, black contours)
700 Streamfunction (x106m2s-1, black contours) and Windspeed (ms-1, shaded)
Aug 31. 2006Date Propagation
SpeedLightning Stripe Length (degrees)
Squall line length
Aug. 31 19 m/s 11 deg. 660 km
Additional Comments: Appears to be a continuation of the previous event.
925 Vorticity (2x10-5s-1, red contours) and 700 Streamfunction (x106m2s-1, black contours)
700 PV (0.1 PVU, shaded) and Streamfunction (x106m2s-1, black contours)
925 θv (K, shaded), Vorticity (>2.5x10-5s-1, red contours), and Streamfunction (x106m2s-1, black contours)
700 Streamfunction (x106m2s-1, black contours) and Windspeed (ms-1, shaded)
Sep 5. 2006Date Propagation
SpeedLightning Stripe Length (degrees)
Squall line length
Sep. 5 18 m/s 18 deg. 1250 km
Additional Comments: Convection began behind an AEW and followed a strong surge of cool air into the SHL. Strong easterly flow > 25 m/s.
925 Vorticity (2x10-5s-1, red contours) and 700 Streamfunction (x106m2s-1, black contours)
700 PV (0.1 PVU, shaded) and Streamfunction (x106m2s-1, black contours)
925 θv (K, shaded), Vorticity (>2.5x10-5s-1, red contours), and Streamfunction (x106m2s-1, black contours)
700 Streamfunction (x106m2s-1, black contours) and Windspeed (ms-1, shaded)
Sep. 12. 2006Date Propagation
SpeedLightning Stripe Length (degrees)
Squall line length
Sep. 12 19 m/s 31 deg. 1330 km
Additional Comments: Occurred in a fairly intense AEJ couplet on the N side of the upstream trough possibly aided by the ridge built behind the Helene AEW. Looks like a recharge of the low-level theta e following the Helene AEW at low-levels. Moving into the post-monsoon-surge environment following Helene AEW.
925 Vorticity (2x10-5s-1, red contours) and 700 Streamfunction (x106m2s-1, black contours)
700 PV (0.1 PVU, shaded) and Streamfunction (x106m2s-1, black contours)
925 θv (K, shaded), Vorticity (>2.5x10-5s-1, red contours), and Streamfunction (x106m2s-1, black contours)
700 Streamfunction (x106m2s-1, black contours) and Windspeed (ms-1, shaded)
Sep. 14. 2006Date Propagation
SpeedLightning Stripe Length (degrees)
Squall line length
Sep. 14 18 m/s 6 deg. 560 km
Additional Comments: Very cold cloud tops (< -80C) occurred in the NW sector of a developing AEW (just slightly titled PV strip). Occurs within a fairly intense AEJ 20-30 m/s. As seems to be typical of these regions the low-level winds are fairly weak.
925 Vorticity (2x10-5s-1, red contours) and 700 Streamfunction (x106m2s-1, black contours)
700 PV (0.1 PVU, shaded) and Streamfunction (x106m2s-1, black contours)
925 θv (K, shaded), Vorticity (>2.5x10-5s-1, red contours), and Streamfunction (x106m2s-1, black contours)
700 Streamfunction (x106m2s-1, black contours) and Windspeed (ms-1, shaded)
Sep. 24. 2006Date Propagation
SpeedLightning Stripe Length (degrees)
Squall line length
Sep. 24 21 m/s 26 deg. 1250 km
Additional Comments: Line of convection with SE-NW orientation began just south of the ITF and moved toward SW. Convection formed within 20 m/s AEJ jet core east of an AEW.
925 Vorticity (2x10-5s-1, red contours) and 700 Streamfunction (x106m2s-1, black contours)
700 PV (0.1 PVU, shaded) and Streamfunction (x106m2s-1, black contours)
925 θv (K, shaded), Vorticity (>2.5x10-5s-1, red contours), and Streamfunction (x106m2s-1, black contours)
700 Streamfunction (x106m2s-1, black contours) and Windspeed (ms-1, shaded)
