Friday, February 10, 2017
Friday Morning Ensembles
Just a quick look this morning at the GEFS and SREF ensemble forecasts for QPF at Tucson. The GEFS plumes from 06 UTC last night are shown above. These continue on a drying trend, with the operational GFS (blue) now forecasting little at Tucson. The timing of the event has shifted, with the models forecasting the moisture-starved event to occur on next Sunday night.
The QPF plumes above are from the 09 UTC forecast of SREF system (I snipped these from the SPC web page). This ensemble system forecasts the event to begin Sunday afternoon and continue into Sunday night. The scale is at 0.10" intervals and the dark purple trace tops out at about 0.55" with average around 0.10". The SREF trend is, however, toward slightly higher QPF, as shown by the change in the average forecast QPF amounts from the most recent 4 forecast runs (below). Scale here is 0.01" with the green trace topping out at an increase of 0.05".
Finally, models now forecast chances for precipitation to occur as the 500 mb closed low moves across southern Arizona on Sunday night. Forecast below is from 06 UTC WRF-GFS at Atmo and is valid at midnight, Sunday night. Details of this event remain very fluid in the forecast models, so we'll just continue to watch.
Posted by Bob Maddox at 6:43 AM