Saturday, August 27, 2016
Weekend Dry-Out Coming In From South
The 12 UTC WRF forecasts played out pretty well yesterday, with storms and rain around parts of the greater metro area but much of core city area remaining dry. Here at house we were dry after the pre-sunrise shower but did have a strong outflow from storms over toward the northeast part of the metro.
Image above shows storm with nice rain shaft to north-northeast of Kitt Peak at 6:25 pm MST yesterday. Graphic below is gauge-adjusted radar rainfall estimate from Maricopa County flood control district for 24-hours ending at 6:00 am this morning.
This morning very dry air is swinging around the 500 mb short wave that is over the Lower Colorado Basin - as was also predicted well by yesterday's WRF forecasts. Graphic above is the blended PW analysis from CIRA at Colorado State University for 11 UTC this morning. PW has already fallen below an inch over much of south and southwest Arizona. The dry-out pushes north and eastward during the day - 06 UTC WRF NAM forecast of PW below is valid at 5:00 pm this evening.
Both WRF models from 06 UTC forecast showers only along the eastern edge of Cochise County across the southern third of Arizona - a serious downturn relative to yesterday. The WRF NAM forecast of total rainfall at bottom below is valid at midnight tonight. By early next week, higher PW air will try to push westward from New Mexico back into southeast Arizona, after a dry and warm to hot weekend.
Posted by Bob Maddox at 6:53 AM