Fourth-Place Finish*
As of 10 AM today, the Birmingham-Shuttlesworth Airport had recorded 71.67″ (unofficially) for the year. It’s unofficial because the NWS climate report has not come out for the day; once that comes out, we will be “official.”
So, where does that rank us in Birmingham’s wettest years? This year was the fourth-wettest on record since 1900.
Here are Birmingham’s Top Five as they stand right now:
1. 81.82″ in 1929
2. 76.48″ in 1961
3. 75.36″ in 1932
4. 71.67″ in 2009*
5. 71.45″ in 1920
Tuscaloosa’s yearly total is going to be about 62.87,” and Anniston will be near 66.96.”
All seems well with these numbers, but why the asterisk? What do you make of the reports of 80-90 inches of rain nearby these airports in places like Coker and Clay? J.B. Elliott and I have been discussing whether or not the records might be tainted by a change from a manual 8″ cylinder rain gauge to the automatic tipping-bucket rain gauges between 1929 and today. What do you think? Should the records be examined more closely, or if you’re in the know, do the records reflect a manual observation that we are not aware of? Does anyone really care? 
Here’s an interesting read on the difference between ASOS (automatic tipping-bucket stations) and manual gauges such as the ones used by CoCoRaHs observers. According to the research these folks did at the Colorado Climate Center, the automatic gauges may be as much as 25% less than an old cylinder gauge. (Hat tip to skywatcher Wally Coker for the info):
Automated Rain Gauges vs. CoCoRaHs Manual Gauges.
Your thought for the New Year: which one is correct?
Happy New Year!
Jason
Follow me on Twitter at simpson3340
December 31st, 2009 at 11:00 am
Although I have not tested the theory, I believe it may be right. I have a Davis Vantage PRO 2 and my rainfall total this year shows 60.03 inches. If I add 25% to that, it would be 75.04 inches. Although it is possible that my location just did not get that much rain, it would match up more evenly with totals from surrounding cities. I may have to invest in a good manual gauge this year to check it out for myself.
December 31st, 2009 at 11:01 am
Wow, Jason! Interesting information. In those years that I was a USWB CoOp observer before actually joining the USWB, I used the 8-inch diameter rain gage with the old cedar measuring stick and liked it very well. I still have one today and would not trade it for any other. I am surprised at the difference. However, when I joined the USWB at Birmingham Airport, we had a 12-inch diameter tipping bucket gage that registered on a chart inside the office. During downpours, it would get behind and was not allowed as the official gage. The official gage weighed the rain and we had the 8-inch manual gage as a backup.
December 31st, 2009 at 11:27 am
Interesting. I am partial to the manual gauges like the CoCoRaHs gauge. We want to get it right relative to our measurements and it seems there are just too many discrepancies with the automatic gauges as you all have demonstrated. Happy New Year!
December 31st, 2009 at 11:33 am
I’ve used a glass rain gauge that holds about 5 or 6 inches of rain and has about a 1 inch diameter. I measured just over 83 inches of rain this year in Ross Bridge. Very rarely does the aiport receive more rain than at my location. I’ve often thought about testing the gauge but may do so in 2010.
December 31st, 2009 at 11:35 am
JB or Jason….What would be an affordable rain gauge for those of us who are just getting into the group?
Thanks!
December 31st, 2009 at 11:39 am
Or where do you suggest I go to look for equipment?
December 31st, 2009 at 11:50 am
On Simmons Mt., Springville, my Davis Vantage Pro 2 software shows 75.91 inches YTD (actual reading, not bumped up according to the study). I have a manual rain gauge too, but do not keep records with it. I use it as a comparison on short term rainfall, storms, etc. I have found a fairly close parallel between the two, maybe as much as 10% difference, but not the study difference of 25%.
December 31st, 2009 at 11:53 am
Rocky,
The CoCoRaHs gauges are good, but if you’re just looking for a weather reporting station like most of the skywatchers have, you’re probably going to want a Davis weather station. Google them and see what kind of deals you can find…occasionally you find them cheaper that way. Davis is a little pricey, but it’s worth it over the other brands.
December 31st, 2009 at 12:15 pm
Like I told Jason this morning when he & Ronald Hughes were comparing his reading to Tuscaloosa Airport, and the big differences, that if you want accuracy then you need the certified CoCoRaHS (stratus) guage. I get my “official” reading from mine after the rain/storm event, or at 00:00 hrs. The Stratus is what I use for my “official rain reports”, because the digital tip bucket see/saw just can’t keep up with hvy rain amount totals. BUT, I love my Davis tip bucket for quick, inside the house reports and give a temporary report using it. This is why on our Shywatcher conference I say “davis bucket” or “Stratus”.
December 31st, 2009 at 12:25 pm
Jason wrote: “Should the records be examined more closely, or if you’re in the know, do the records reflect a manual observation that we are not aware of? Does anyone really care?”
How do we really know how accurate the record are from the old days? In today’s world, they should be very accurate. But… as long as humans take the reports, there will be mistakes.
Record low in 1922 was x, who cares if it was one or two degrees off. What difference does it make?
I use a CoCoRaHs gauge for my reports, and I try to be 100% accurate.
December 31st, 2009 at 1:06 pm
My Davis VP2 has 73.30 for 09.
December 31st, 2009 at 5:09 pm
My Davis VP2 has 79.66″.My CoCoRaHs gauge had 84.62″,7.5 miles southwest of Alexander City.