Saturday, January 02, 2016

Mild And Windy This Morning - Wet Next Week

The east winds that the WRF model has been forecasting are impacting the Tucson metro area this morning - wind gusts of 30 to 35 mph have been reported at the airport since about 2:00 am MST, with temperatures in the upper-40s. The winds are not as strong here along the Rillito, but temperatures are mild. Morning lows in metro area are around 10 to 15 F warmer than yesterday.

The current NWS forecast for the airport grid-box is shown above, with rain forecast to begin perhaps as early as tomorrow night. The POPs at airport are forecast at 60% for Monday and again for Wednesday. The POPs are likely 100% for several 12-hour periods (based on GFS forecasts - see plumes below), but the exact timing is more uncertain, given that the first system is still about two days away in the model forecasts.

The WRF-GFS forecast from the 06 UTC run at Atmo (below) shows composite radar echoes covering most of Pima County valid at 5:00 pm MST on Monday afternoon.

The NWS plumes for QPF from the GFS ensemble models (above from 06 UTC this morning) are very interesting.  While the operational version (blue) is usually a dry outlier, it is currently one of the wettest members, forecasting almost 2 inches of precipitation at the airport through early on the 9th of January. It is significant that the consensus average (heavy black) is over an inch for that period.

The GFS operational member's forecast of accumulated precipitation below (from the 06 UTC forecasts) is for the period ending at 5:00 pm MST on Wednesday afternoon (the 6th). So, if the models are anywhere close, we'll have a very significant week, especially given the long dry period since mid-December. It is also interesting that last January was the wettest month of 2015.

The MIMIC composite analysis of PW above covers the entire Pacific at 10 UTC this morning, and does not appear particularly unusual, with a couple of moisture plumes and two distinct atmospheric rivers. What is unusual is that the systems associated with the higher moisture levels are forecast to eventually come ashore into the Southwest.

Best of the New Year - Thanks for Looking

No comments:

Post a Comment