tag:blogger.com,1999:blog-4572286363399496963.post7010964176322133803..comments2024-03-27T04:17:21.221-08:00Comments on Deep Cold: Alaska Weather & Climate: Precipitable WaterRickhttp://www.blogger.com/profile/03946704894714514716noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-4572286363399496963.post-66584888559491651322014-07-25T21:39:54.843-08:002014-07-25T21:39:54.843-08:00Those are interesting questions Gary and Eric. The...Those are interesting questions Gary and Eric. There are certainly a list of contributing factors for heavy rainfall events and PW, in my opinion, isn't much of a driver for precipitation frequency but it does seem to turn a 0.2" rain into a 0.3" rain. My recollection is that this July's heavy rainfall events occurred with an upper level low in the Gulf of Alaska and short waves rotating in from the east. The cold air aloft probably increased the instability and there may have been a thermal trough at the surface but I could easily be mistaken about that. As stated in the blog post, the three largest rainfall days had an average PW of over 1" (max since 1971 in June/July is 1.4").<br /><br />As for long-term PW tracking, the balloon data that I used selectively filters out a lot of data prior to 1971 so it is difficult to calculate PWs prior to then. There is an alternate, more robust data set but its interface is much more difficult and the files sizes are too large (for me) to manage as a batch file. In any event balloon data only foes back to 1948 so long-term trends would be tough to extract in any event.Climatologist49https://www.blogger.com/profile/04560505931210357679noreply@blogger.comtag:blogger.com,1999:blog-4572286363399496963.post-57150306608833052092014-07-25T21:26:05.396-08:002014-07-25T21:26:05.396-08:00I had an interesting conversation with the Aquati...I had an interesting conversation with the Aquatic Ecologist linked below today. It dealt with studies currently underway on Federal Lands by NPS scientists. It ties into the potential variability of wetness Eric mentions.<br /><br />http://science.nature.nps.gov/im/units/cakn/Documents/resource%20summaries/RS_lakesDENA_mar08.pdf<br /><br />http://science.nature.nps.gov/im/units/cakn/vitalsign.cfm?vsid=34<br /><br />GaryNL7Yhttps://www.blogger.com/profile/15874712728971005352noreply@blogger.comtag:blogger.com,1999:blog-4572286363399496963.post-91966503592572855422014-07-25T19:33:24.735-08:002014-07-25T19:33:24.735-08:00Another idea: supposedly Alaska has been getting w...Another idea: supposedly Alaska has been getting wetter over the last few decades. Is there any correlation with increasing precipitation and increasing PW? Basically, how much of increased precipitation is from added moisture and now much is from different precipitation drivers (more cold fronts, occulations, etc.)? Of course this is assuming the data isn't too random to make out.Eric Lundellhttps://www.blogger.com/profile/17914784378747801359noreply@blogger.comtag:blogger.com,1999:blog-4572286363399496963.post-45252192052865077102014-07-25T18:39:09.232-08:002014-07-25T18:39:09.232-08:00It would seem that it takes at least 'two or t...It would seem that it takes at least 'two or three to tango' when it comes to major widespread rain events. Moisture (PW?) and the ability of the atmosphere to retain it as influenced by air temperature may be some participants. A non-standard lapse rate and CAPE values likely play their hand as well some days, especially if thunderstorms are about.<br /><br />So my question : Which condition(s) prevailed during the major rain events this summer? I'm going to guess typical Occlusions also played a role at times.<br /><br />Gary<br /><br />NL7Yhttps://www.blogger.com/profile/15874712728971005352noreply@blogger.com