Wx fcst 0800MDT W 13 Apr 11

Looks like a lot of potential with this situation, but also a fair degree of uncertainty. Well defined upper trough near to just off W Coast attm is xpctd to move inland with no further southward deepening, and swing across CO on Thursday, to be followed by a 2-3 days of mostly W to NW winds aloft Friday into Sunday.

The Thursday trough passage aloft will be accompanied by marked deepening of a surface low on the plains, due to the overall low static stability, and the sharpness of the trough aloft. I anticipate that there will be passage of a Pacific front that will be trackable across the Great Basin today and tonight. This frontal passage, anticipated near dawn on Th, will likely be accompanied by some westerly wind and pcpn as it scours out the cooler moist upslope air that oozed in last night. Following that, as the surface low deepens, most likely initially over eastern CO and then moving into KS / OK + TX panhandles, there will be surface winds from W - N. Westerly winds are more likely if the surface low develops farther north, northerly if the low develops farther south. In any case, there is a definite threat of pcpn behind the Pacific front, mainly Th morning. Right now I see the best chance of high wind to be between 2pm MDT Th and 2am MDT F, but confidence is not as high as I would like. I put the chance of a gust > 25m/s during this period at the 10m level on the M2 tower as 50%.

Looking farther ahead, I think Friday there is likely to be cool air aloft with NW flow, and with April sun there will be opportunity for a deep mixed layer that will allow the higher-momentum air to mix down to the surface during daylight hours. Chances of 10-m gusts > 15m/s I put as 70% during daylight hours on F. A similar situation may prevail on Saturday. The possibility of a period of wave-induced strong (> 18m/s) wind on Friday night also cannot be ruled out.

I will take another look before 1300MDT today (W) and note on the blog.