Thursday, October 18, 2018

Showers Possible This Weekend

Yesterday was an interesting situation wrt the strong easterly winds. The airport recorded gusts as high as 38 mph during the day. However, over around the Santa Ritas and Mt. Hopkins, the easterly winds reached only to about half the mountain heights, and were not deep enough to trigger the very strong gap winds that are often measured at the Hopkins RAWS site. The WRF forecasts captured the wind structure quite well, indicating east winds veering to southerly by mountain top levels. Result was maximum gusts of 36 MPH at the RAWS site - less than those down at TUS.

Total PW (above is MIMIC PW analysis for 5:00 am MST this morning) is low across most of Arizona; however, more moist air is has inched northward along the east coast of the GoC. There is also higher moisture to our east over southern New Mexico and southwest Texas, where rainfall is fairly widespread.

The 06 UTC WRF forecasts indicate moisture initially increasing here from the east, and then later from up the GoC. Forecast below is of PW from the GFS version on the 5.4 km grid - it is valid at 5:00 am on Sunday the 21st.

Forecast plumes from the GEFS indicate a rapid increase of PW through Friday at TUS (above). The moisture increase results in a chance for light showers over the weekend - below. The increased moisture is forecast to interact with another weak wave approaching from our west - at least something to watch as weekend approaches.

No comments:

Post a Comment