01Z Tu 26 Apr 2011 Forecast Discussion

From the lack of blog activity I gather that no data was collected today. The strongest 10m gusts I saw were between 12 and 15m/s, and these are continuing. This aftn a Cirrostratus / Altostratus overcast has overspread the area, harbinger of the next in this seemingly unending series of systems parading across us. This one does appear to have potential to bring a good wind event, especially for so late in the year.

Indications favor weak to moderate cyclogenesis on the plains as this short-wave trough crosses the Divide Tuesday morning 26 Apr. There appears to be a tracable Pacific front currently in eastern UT, with some precipitation on Colorado's western slope ahead of it. The current winds in Boulder may be partly augmented by evaporational cooling from this pcpn; if so, then we can expect the current breezy conditions to continue well into the evening, but then quiet down through most, if not all, the remainder of this Monday night. However, after the Pacific front passes, most likely soon after dawn, we can expect winds to pick up, augmented as so commonly this time of year by vertical mixing of westerly momentum as the daytime mixed layer behind the front deepens rapidly. I look for winds to reach gusts of 18-20m/s by noon Tuesday at M2, and continue strong, at least intermittently till W mrng 27 Apr. Strongest winds right now look to be Tu aftn and evening, with probability of peak gusts on M2 > 18m/s during the noon to 6pm period being 80%, and probability of gusts exceeding 25m/s being 30%. Similar probabilities apply for the 6pm to midnight period.

Wind is likely to become more intermittent in the evening and through the night.

Looking farther ahead, I suspect we may see some gusts at M2 W late morning through late aftn as a result of vertical mixing of momentum. There is a possibility of more windy afternoons after W.