Thursday, August 10, 2017

Early AM Thunderstorms

Much more interesting than I expected yesterday, especially during the night last night. Top shows afternoon storms over Redington Pass area - these tried to move into the metro area but mostly fizzled. However, a band of thunderstorms with light showers moved northwestward across portions of metro between 3:00 and 5:00 am MST this morning. Received 0.10" here at house. Trailing clouds at sunrise produced a slight, morning rainbow - below.

Detected CG flashes above are for 24-hours ending at 6:30 am, from Atmo and Vaisala - yellows to pink to white show the morning storms. Below is rainfall across northern 2/3rds of ALERT network ending at 8:00 am.

There was a game-changing, huge MCS over Sonora last night - above IR image is from 0630 UTC. This system moved over northern half of GoC, producing moisture surges into Arizona. Current dewpoint at Yuma is 78 F and Doppler VAD winds below show strong, southerly winds up to 5,000 ft MSL or so.

The 12 UTC 500 mb analysis (above from NCAR)  shows the anticyclone has shifted eastward and is now centered along New Mexico - Texas border, resulting in stronger winds here from the southeast. The 12 UTC sounding plot for TWC (below) shows a typical onion sounding produced by the morning showers. This leads to question of what will conditions be like this afternoon? The wind profile is quite favorable for organized storms; however, the boundary layer will have to re-develop because of the rain-cooled low-levels. This will probably result in a sounding with CAPE but with outflows need to develop storms at low elevations. The visible image at bottom from 7:30 am seems to indicate the clouds are already thinning to our east, leaving hope for considerable heating and recovery.

Bottom line - very tough forecast situation that could be helped some by a special 18 UTC sounding for TWC.

1 comment:

  1. Mike Hardiman11:02 AM

    Unfortunately, giphy shrunk the images, but you might enjoy this GOES-16 Infrared animation. Anything purple is -80C. At 0407Z, there was even a -91.0C pixel halfway between Hermosillo and Ures. (Since G16 is still technically 'non-operational', it is possible that the values are not calibrated quite right.)