CASE 26 - Weak convection along landbreeze front


Microphysical scans 0915 - 1115 Z, 2h





Upper level ridge axis was shifting to the SW of Baja and a small PVA zone associated with old IV#10 was located over S AZ. The precipitation pattern in SW US was indicative of moisture advection from the SW.







Day 0 forecast discussion text



200 mb - model.ETA.200408141200.00_200mb_wnd.gif

500 mb - model.ETA.200408141200.00_500mb_wnd.gif

700 mb - model.ETA.200408141200.00_700mb_wnd.gif

850 mb - model.ETA.200408141200.00_850mb_wnd.gif


Mazatlan SkewT - ops.SkewT.200408110900.Mazatlan_MX.gif - ops.SkewT.200408111200.Mazatlan_MX.gif



EVENT SUMMARY: An evening landbreeze developed and propagated offshore at around 0730Z. As this boundary moved offshore, it spawned a few moderate-intensity cells. Overall, convection was short-lived and disappointing.


24 h precipitation totals -





S-Pol log - spol_081404.txt




0730 Z

Land breeze propagating offshore.


0915 Z

Begin Microphysical Scanning, Switching to MicroFar90: Hoping to capture the lifecycle of cells developing along landbreeze offshore of Mazatlan. Strongest cell (45-50 dBZ) is at 156 deg / 70 km. Cells now forming close (30 km) to the radar.


0915Z, Base reflectivity


1015 Z

Switching to MicroNear90: Switched in order to top cell at 35 km - far cell dying.


1015Z, Base reflectivity


1045 Z

Switching to MicroFar90: Nearby cell is weakening, less deep.


1045Z, Base reflectivity


1115 Z

End Microphysical Scanning, Switching to ClimoShallow: Landbreeze cells have died out.


1115Z, Base reflectivity