Wednesday, November 16, 2016
Precipitation Event Early Next Week?
The waning super-moon this morning before setting over the Tucson Mountains.
Early next week the southern end of a Pacific trough moves into the Southwest. The 00 UTC WRF-GFS forecast for PW (above on the 5.4 km grid) brings a substantial plume of subtropical moisture into Arizona ahead of the short wave - above forecast valid at 8:00 am Monday, November 21st. The model also forecasts a significant precipitation event over southeast Arizona for next Monday, and the NWS POPs for the airport on Monday are currently an aggressive 70%. However, the 00 UTC GEFS plumes for precipitation indicate considerable spread among the various members forecasts for the event on the 21st. Of note, is that the operational GFS (configured differently than the ensemble versions and shown in blue) is a wet outlier wrt to all the GEFS members. We'll have to see if the operational forecast dries out as the event nears - this transition from wettest to driest has happened several times this Fall.
Posted by Bob Maddox at 7:15 AM