Saturday, November 26, 2016
Quick Look For Tomorrow Night
Models continue to bounce around for Sunday night weather event, but what's certain is that it will bring a significant cool-down. Above graphic shows the GEFS plumes for QPF at airport from 00 UTC yesterday evening, with three members continuing to forecast 0.00" for TUS and three other members forecasting over 0.30". The operational version of the GFS (blue) is essentially the same as the ensemble average, with its forecast of just over 0.10". The next run at 06 UTC indicated all members forecasting measurable rainfall.
The NWS high-resolution, hourly grid forecast for TUS (above) was probably driven by the 00 UTC operational forecast shown at top. From 5:00 PM MST tomorrow through 5:00 am Sunday morning the forecast for TUS indicates POPs of 51 to 16%. Current NWS forecast for airport is 50% for at least 0.01". During this period the grid forecast indicates that 0.10" of rain will fall at airport. Obviously, if the QPF forecast verifies, then several of the hourly POPs will have to be busts as will the NWS 50% POPs - just one of the many inconsistencies that plague NWS forecasts.
Meanwhile, the 00 UTC WRF-GFS forecast on the 1.8 km grid (also driven by the blue curve at top) continues to forecast no rainfall at the airport through noon on Monday - below. The 06 UTC WRF-GFS also forecasts no rain at TUS. What's actually going to happen at airport regarding rainfall? Hard to tell from this GFS mish-mash, especially since PW forecasts indicate there will be little available moisture during event.
Posted by Bob Maddox at 6:50 AM