Monday, August 21, 2017

Serious Over-Forecasts Yesterday -Miscellany Today


Yesterdays forecasts (me, NWS, and models except for 15 UTC WRF-RRx) seriously over-forecast the likely hood of thunderstorms for all of southeast Arizona. I thought mountain storms would occur and inch westward, closer to Tucson, NWS had 30% POPs for measurable rainfall at the airport last evening, and most models also had rainfall over portions of southeast Arizona. The exception was the WRF-RRx which forecast absolutely nothing, which is what occurred. The suppressive impacts of the weak short wave that pulled northeastward toward Colorado were much greater than anticipated. So it goes in summer forecasting.

The 24-hour plot of detected CGs above ends at 1330 UTC this morning (from Atmo and Vaisala) - note that the lack of thunderstorms covered a huge area extending from southern California eastward across New Mexico. The WRF forecast shown in previous post was really bad across New Mexico. Luckily for most weather folks, today's eclipse is absolutely top news, allowing yesterday's lack of storms and rain to be totally ignored. 

Dry air encroaching from the west at lower-levels, and dry air already aloft, make it look a repeat for next day or two. This morning's sounding plot for TWC (below) is even more miserable than yesterday's.



As for the eclipse - the early morning visible image (above from 1330 UTC) shows most of the Northwest clear and only one band of clouds from south Idaho across northern Wyoming as a potential trouble-maker.  Things much more iffy from Nebraska eastward.

Mean while, far out in the Pacific, hurricane Kenneth has strengthened to a Category 4 storm - IR of Kenneth below also from 1330 UTC.


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