October Frustrations Continue

The extended period of no rain continues, and model forecasts at longer ranges indicate that the month may close out with absolutely no rain.

Easterly winds during the night kept temperatures very mild, as would be expected. The low at NWS was 70 F (15 F warmer than yesterday), and 68 F here at house (20 F warmer than yesterday). The NWS late afternoon forecast valid at the airport grid point was for a morning low of 61 F - significant difference that shows the difficulty of certain parameter forecasts even under benign synoptic patterns (also see below re winds). However, the 12 UTC WRF-GFS forecast yesterday morning was very accurate - above graphic shows the model's 24-h forecast valid at 5:00 am this morning. 

The winds have gusted into the 30s (mph) at the airport at times since yesterday; however, the winds at Mt. Hopkins have been lighter (gusting only briefly to 31 mph yesterday) than indicated from the model forecasts from 00 UTC Sunday evening. This illustrates again the dangers of trying to make a specific point forecast too far in advance. The Sunday evening forecast sounding for Sonoita indicated strong easterly winds up to around 700 mb. But this morning's TWC sounding and the the WRF-GFS forecast sounding from 12 UTC yesterday morning (below, valid at 5:00 am MST today) show a much shallower layer of easterly winds. So it goes.

Finally, back to following the GFS and ECMWF forecasts for 500 mb valid at 00 UTC on the 28th of October. These are the 72-h operational forecasts valid at that time from last evening (above is GFS and ECMWF below). There are still some important differences, even at this close range. The ECMWF is a bit slower for the closed low over the upper-Midwest than is the GFS. Specfic point differences are: at the Four Corners - GFS 5700 m and ECMWF 5760 m - and at Chicago - GFS 5400 m and ECMWF 5520 m. The heights over the upper-Midwest are important, since this system could bring the first snowfall of the season for places like Minneapolis and Milwaukee. Will check back in future post to see final numbers and weather for 00 UTC on the 28th.