Is Flagstaff wetter than Munich?

 Climate, Northern Arizona Weather  Comments Off on Is Flagstaff wetter than Munich?
Oct 302015
 

My current frame of reference is Munich. It’s been mostly foggy with cool clear nights cause the still relatively warm moist ground to product fog. But, rainfall and first snow have been on my mind.

3.68 inches of rain have fallen in Flagstaff in October. This is more than double the normal amount. Below is the rainlog.org picture for October in the Flagstaff Area. As always, there is much variability. Overall, it was a wetter than normal month for Flagstaff, but very far from a record. This make the 12 month precipitation total 27.39 inches.

My weather station here in Munich has measured 3.5 inches of rain. Munich’s average precipitation is 2.68 inches at the airport. So, both Flagstaff and Munich have had a wet October, but I think Flagstaff has been wetter.

October rainfall for the Flagstaff area reported on rainlog.org. (through October 30, 2015)

October rainfall for the Flagstaff area reported on rainlog.org. (through October 30, 2015)

 Posted by at 11:29 pm

Comparisons of Atlantic Sea Surface Temperatures and Flagstaff Precipitation

 Northern Arizona Weather  Comments Off on Comparisons of Atlantic Sea Surface Temperatures and Flagstaff Precipitation
Oct 242015
 

I continue to be interested in the Atlantic Multidecadal Oscillation(AMO) impact of Flagstaff precipitation. It surprises me that there could be a link between the sea surface water temperatures in the North Atlantic and the rain and snow amounts on the other side of North America, in a desert.

I past posts, I have discussed the image below and the link of AMO and Flagstaff precipitation.

Drought frequency (in percent of years) for positive and negative regimes of the PDO and AMO. (A) Positive PDO, negative AMO. (B) Negative PDO, negative AMO. (C) Positive PDO, positive AMO. (D) Negative PDO, positive AMO(http://www.pnas.org/content/101/12/4136.full).

Drought frequency (in percent of years) for positive and negative regimes of the PDO and AMO. (A) Positive PDO, negative AMO. (B) Negative PDO, negative AMO. (C) Positive PDO, positive AMO. (D) Negative PDO, positive AMO (http://www.pnas.org/content/101/12/4136.full).

The basic summary is that if the Atlantic is cool (AMO Negative) and the Pacific is warm (PDO Positive), Northern Arizona should have a lower risk of drought. But, does the AMO alone have a noticeable effect on Flagstaff precipitation. Using the data from NOAA at their Earth Systems Research Library, and the precipitation data for Flagstaff since 1950, a potential match in the data sets appears. (I only use the data back to 1950 because the National Weather Service’s Flagstaff measurement location moved from downtown to the airport in 1950.) To help reduce short-term effects, I used the smoothed data for the AMO and last 12 months precipitation total. Here is the resulting graph:

Last 12 month total previpitation and Atlantic sea surface temperature AMO index.

Last 12 month total precipitation and Atlantic sea surface temperature AMO index.

Looking at the AMO data, I see three zones In the first zone, the AMO is mostly positive and ends around January 1963. In the second zone, it is mostly negative and goes through July 1995. In the last zone, it is mostly positive. Here is another graph with those zone highlighted.

Last 12 month total precipitation and Atlantic sea surface temperature AMO index.

Last 12 month total precipitation and Atlantic sea surface temperature AMO index.

Looking at the each of these zones, there also appears to be a difference in the 12 month precipitation amounts.The first and last zones have a lower average. But is that enough?

Looking at a histogram of the precipitation data shows the trend more clearly.

Histogram of 12 month total precipitation.

Histogram of 12 month total precipitation.

The first and last zones have their peaks at lower precipitation amounts. There is still plenty of overlap between the zones, but the 1963-1995 zone has a higher average and a longer tail at the higher amounts. The Atlantic sea surface temperatures seem to have an effect on Flagstaff’s precipitation.

One lingering point concerns me. The is a recent upward trend since about 2010. The AMO data above includes the entire North Atlantic, from the Equator to 70 degrees North. This view might not be the best. There has been a persistent band of cold water in the far northern region of the Atlantic for about the last two years. This matches a move to a higher average precipitation recently. A better subset of the North Atlantic might be worth considering.

 

 

 Posted by at 1:46 am

Missing the October event

 Northern Arizona Weather  Comments Off on Missing the October event
Oct 202015
 

Yesterday I occasionally watched the weather radar as events emerged across Arizona. I could tell Flagstaff was going to get an early morning wake-up call from Mother Nature. And Mother Nature did not disappoint.

I did miss being in Arizona to see it first hand. October storms like this are often some of the most interesting to me. To me, if not the data, October is often a drier month with lots of wind. The occasional storm is more fun than wind.

With the recent precipitation, October is well above average for precipitation. With 3.21 inches, Flagstaff is roughly double the monthly average since 1950. The Northland can expect more rain today, but then a drier trend is on the way with lower chances through Friday, and a clear fall weekend.

 

 Posted by at 8:53 pm

If you liked last week, you’re going to like the rest of the month.

 Climate, Models, Northern Arizona Weather, Outlooks  Comments Off on If you liked last week, you’re going to like the rest of the month.
Oct 102015
 

It’s been a while since my last post. This is all thanks to Apple. I bought a new laptop because using my big MAC in Germany isn’t practical anymore. We just don’t have the room for it. After a week of using the new laptop, the arrow keys broke. The first chance I had, I took it to the Apple Store to have it replaced or fixed. They wanted to fix it, but the part would take some time. I could still use the computer, but not easily. Then I took it back when the part came in. They said I would receive a message in 3-5 days. After a week I called. They told me it would be another week before they got to it. Sheesh. I feel like just gave Apple a loan of over a thousand bucks for a month! This is not Steve Jobs’ Apple!

Deep cleansing breath in…and out.

So, I missed blogging about the rain last week. With the airport receiving 1.27 inches of rain, Flagstaff is well on its way to an above average rainfall month. The average October precipitation in Flagstaff since 1950 is 1.54 inches. With the outlooks for the next few weeks, we should easily surpass the average.

I’ve taken the current 6-10 day, 8-14 day, 3-4 week, 1 month and 3 month outlooks and made an animated gif. This is below.Most of Arizona is comfortably inside the above normal chances for above average rainfall for all time periods.  El Nino and the disappearance of the Ridiculously Resilient Ridge are driving this. I wonder when the first big snow will show up. It could be this month.

Also, the North Atlantic is colder than normal. This can also mean a wetter than normal winter. I plan to do some more on this topic when I get my laptop back. The spreadsheets are on the laptop.

Animated gif of 6-10 day, 8-14 day, 3-4 week, 1 month and 3 month precipitation outlooks from the Climate Prediction Center.

Animated gif of 6-10 day, 8-14 day, 3-4 week, 1 month and 3 month precipitation outlooks from the Climate Prediction Center.

 Posted by at 12:29 am
Sep 252015
 

In the last two months, the Climate Prediction Center has not been very accurate with their 1-month precipitation outlooks. July and August precipitation amounts were close to average. September’s precipitation amount is running well below average. On the other hand, they we right about April, May and June. The long-range outlooks continue to show a strong, El Niño winter.

They have now released an Experimental 3-4 week Outlook. This was a gap in their forecasting portfolio. On their home page, They had outlooks for 6-10 days, 8-14 days, 1 month, 3 months, Hazards and Drought. Below is the current 3-4 week precipitation outlook.

Precipitation outlook for weeks 2 and 4 in the future from the Climate Prediction Center.

Precipitation outlook for weeks 2 and 4 in the future from the Climate Prediction Center.

Looks very wet. However, in their discussion they state:

Following ensemble prediction system forecasts from the CFS, ECMWF and JMA, the forecast for the week 3 and 4 period favors above-median precipitation for the Southwest region extending eastward across Texas into parts of Louisiana. This is somewhat consistent with statistical forecasts based on El Niño, however this tool does not appear to have great skill for precipitation forecasts under El Niño conditions at this time of year, indicating the probable influence of additional climate variability on the precipitation pattern.

So, we will have to wait and see. I think late September through November are the toughest months for forecasting Northern Arizona’s weather.

It appears the Ridiculously Resilient Ridge and the related Pacific Blob are going away. Deep details are at The California Weather Blog. The Ridge created the Blob, which reinforced the Ridge, which reinforced the blob, and so on. The ridge is breaking down. The Blob should also disappear over the winter. This is very good news for California and may help reinforce a strong El Niño winter for Arizona.

One last thought, the Atlantic Multidecadal Oscillation is continuing to look like it has shifted. This could be a strong long-term signal for wetter conditions in Arizona.

 Posted by at 10:19 pm

Where does the winter of 1992-1993 fit?

 Climate, Northern Arizona Weather, Pontification  Comments Off on Where does the winter of 1992-1993 fit?
Sep 192015
 

The start of next week may be very wet! Also, the 1 and 3-month outlooks are wet. Just so you know.

But, after posting a link on Facebook to Scientific American article (How This Year’s El Niño Compares with the Past), I got a challenging question from MN about the winter of 1992-1993. In deed, this was probably one of the wettest winters in the last 60ish years. In December of 1992, Flagstaff received 6.78 inches of liquid water precipitation. In January and February of 1993, Flagstaff received 9.55 and 10.05 inches of precipitation. Also, these months were part of a longer term wet period. In the 12 months before the end of February 1993, Flagstaff reached over 48 inches of water. That more than double our typical one year normal. This peak is clear in the chart below.

12-month and 2-year Flagstaff precipitation totals.

12-month and 2-year Flagstaff precipitation totals.

It looks like the winter of 1992-1993 must have been an El Niño year. In 3 months, about 27 inches of water. Must have been….

The winter of 1992-1993 was not a El Niño winter. But, it overwhelmingly surpassed the so-called Great El Niño of 1997-1998. It was about as close to La Nada, neither El Niño or La Niña, as it could get.

Maybe because of my recent readings, the Atlantic Multidecadal Oscillation (AMO) came to my mind. This is a very long-term change in Atlantic Ocean temperatures. I covered it a bit in my last post. With neutral Pacific conditions, perhaps the AMO was in the driver’s seat.

Atlantic Multidecadal Oscillation Index. (http://www.esrl.noaa.gov/psd/data/timeseries/AMO/)

Atlantic Multidecadal Oscillation Index. (http://www.esrl.noaa.gov/psd/data/timeseries/AMO/)

The AMO went from nearly positive to considerably negative in the time leading up to that winter. So, I think at least from a non-expert, looking at a couple of charts point-of-view, the Atlantic could have been an important factor in the winter of 1992-1993 for Flagstaff.

Also, notice that was the last hurrah for wet conditions. After that winter, the AMO started to switch to a persistent positive mode. From my last post, there is a linkage between positive AMO conditions and drier conditions for the American Southwest.

One more note. Many of the people who are my age and grew up in Flagstaff in the late 1960s through the early 1990s, have a profound impression of Flagstaff having been much wetter growing up. On the other hand, some of the people who grew up before that time frame, seem to remember a drier time that was more like today. Completely anecdotal, but interesting.

 Posted by at 12:02 pm

I bet you think the end of Monsoon season is near

 Northern Arizona Weather  Comments Off on I bet you think the end of Monsoon season is near
Aug 312015
 

Yet again, an East Pacific hurricane is going to bring plenty of moisture to Arizona. It just showed up in the computer models, so it may not happen. If it does, 2-4 inches of rain could show up this week. More later.

In München, es ist schön. Aber, morgen Abend wird es regnen und zu kalt.

 Posted by at 12:07 pm

Now, live from Glockenbachviertel, the weather…

 Northern Arizona Weather  Comments Off on Now, live from Glockenbachviertel, the weather…
Aug 292015
 

After several failed attempts and lots of translation about a thing called a Fritzbox, I finally have a weather station up and running here in Munich. You can view it on Weather Underground as station ID IBAYERNM52.

I’m using a very nice, get one for yourself because its cool, Acu-Rite Pro 5-in-1 Weather Station. with an Acu-Rite internet bridge. For historic note, it seems like there were one or two key reason it didn’t connect to the Fritzbox. Either it needed a particular cable for the Fritzbox, or the automatic speed negotiation wasn’t possible. I inserted an Ethernet switch between the bridge and the Fritzbox. The switch is handling all of the connection issues nicely.

I continue to amazed at how similar this summer in Munich has been to a typical Flagstaff summer. Speaking of typical, it appears August in Flagstaff is very typical. More on that after the month is over.

 

One note about tropical storm Erica. She is falling apart because of El Nino produced wind shear. I think the strength of the winds is important for driving Northern Arizona towards a wet winter.

 Posted by at 12:31 am

Short and long range outlooks continue to look wet…very, very wet.

 Northern Arizona Weather  Comments Off on Short and long range outlooks continue to look wet…very, very wet.
Aug 232015
 

Last week, the Climate Prediction Center published new outlook maps. These point to a strong finish for the monsoon season and a wet winter. While these aren’t changes to expectations, I thought they are reviewing. First the current 30-day and 90-day outlooks show the strong finish to the monsoon season.

30-day precipitation outlook from the Climate Prediction Center.

30-day precipitation outlook from the Climate Prediction Center.

 

90-day precipitation outlook from the Climate Prediction Center.

90-day precipitation outlook from the Climate Prediction Center.

Arizona is deep inside the highest probability region for greater and average precipitation for both time frames. I don’t think this monsoon season will be a record breaker, but it should finish strong. The other positive to note is the green zone creeping into California.

For fun, I made animated gif of the other 3-month outlooks through next spring. You can see that until the Mrach-April-May 2016 map, Arizona is firmly in the green zone. Still, this is strongly based on the El Nino conditions we have in the Pacific. We still aren’t clear about how the Pacific Blob and the Ridiculously Resilient Ridge will affect things.

2015-2016 precipitation outlook until next spring. Animated gif of 3-month time ranges. Original images from the Climate Prediction Center.

2015-2016 precipitation outlook until next spring. Animated gif of 3-month time ranges. Original images from the Climate Prediction Center.

 Posted by at 2:18 am

El Nino versus the Blob

 Northern Arizona Weather  Comments Off on El Nino versus the Blob
Aug 152015
 

It’s like a Godzilla movie. Will the current El Nino be the biggest of all time? Will California ever recover from their drought? Is this the Godzilla of all El Ninos.

Global sea surface temperature anomaly animation, August 5, 2015. From Climate Prediction Center.

Global sea surface temperature anomaly animation, August 5, 2015. From Climate Prediction Center.

Just today, a friend of mine shared a post on Facebook that referred to the current El Nino as the “Godzilla” of El Ninos. Granted this El Nino is strong. But, it isn’t completely on-track to be  bigger than the one of 1997-1998. You can read details at Bob Tisdale’s website: August 2015 ENSO Update – Another Westerly Wind Burst in Late July Should Help El Niño Evolve. The El Nino of 2014-2015 did not quite cool off. More westerly wind bursts have caused more robust El Nino conditions. Normally, this should bode well for a strong winter precipitation pattern in the Southwest.

Enter the Blob. Since about 2013, there has been a phenomenon called “The Ridiculously Resilient Ridge.” This area of high pressure has hung around off the West Coast of the US. It has blocked the normal winter jet stream from bringing storms to California, and often parts of the Southwest. While Flagstaff is looking very healthy for precipitation by the year-to-date or water year since September, the core of last winter was dry. One of the results of the ridge is the Blob of warm water off the West Coast. This ridge of high pressure could be very significant for the upcoming winter.

High pressure can alter, or block, the flow of the jet stream, and the storm track. One of the key features of El Nino is that the normal single winter storm jet stream splits into two jet streams; northern and southern. The southern jet stream brings the storms to Northern Arizona and most of the Southwest in the winter. Also, the normal flow in the Northern Hemisphere around high pressure is clockwise. Depending on the position and strength of The Ridiculously Resilient Ridge, this could block the flow of winter storms, Potentially driving them further south and east.

Alternatively, if the ridge breaks down, the warm water would add to the moisture supply to the Southwest.

Sigh…

The current outlook for next winter, December-February, from the Climate Prediction Center is going with the standard El Nino outlook.

Precipitation outlook for December 2015-February 2015. from the Climate Prediction Center.

Precipitation outlook for December 2015-February 2015. from the Climate Prediction Center.

I think they did the same things last year around this time. In a little while, probably sometime in September, the National Weather Service in Flagstaff will provide a slide set that shows that El Nino does not mean a guaranteed wetter than normal winter.

Sigh!

But, this part is unusual for an El Nino year, the December-February outlook for temperature is different from a typical El Nino. The outlook below shows below average temperatures. Typically, El Nino winters are warmer and wetter than normal.

 

Temperature outlook for December 2015-February 2016. From the Climate Prediction Center.

Temperature outlook for December 2015-February 2016. From the Climate Prediction Center.

Sign!!!

So, I am watching. I am wondering. I don’t think the experts even know. Blob versus El Nino…stay tuned.

***********************************************************************************************************

For more on the Blob, I recommend reading the post August 2015 Update for the Blob at Bob Tisdale’s website. He is an expert on sea surface temperatures.

For more on the outlooks, follow the links above and you can find the discussions supporting the long-range outlooks at the Climate Prediction Center.

 Posted by at 10:52 am
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