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Julys, July’s or Julies? Well, they’ve been wet.

 Climate, Monsoon, Northern Arizona Weather  Comments Off on Julys, July’s or Julies? Well, they’ve been wet.
Aug 062017
 
8-14 day precipitation outlook from the Climate Prediction Center from 4 August, 2017.

I did check on dictionary.com. At that site, Julys or Julies are both deemed correct. However, as I type in the WordPress editor, Julys has a red dotted line under it. Well, anyway, I’ll use Julies since that will create the most confusion. Four of the last 8 have been more than one standard deviation above the average rainfall for July going back to 1950. This is one of many indicators that Flagstaff continues to climb out of the drought of the late 1990s through roughly 2010. For instance, Lake Powell’s current water level is at its third highest in the last 10 years.

With 4.48 inches falling last month, that brings the water year (September through August) to 22.9 inches and the calendar year to date to 14.29 inches. Both are above average compared to 18.75 and 11.08 inches. The average July precipitation, according to the National Weather Service, is 2.61 inches. Rainlog.org has a new format, but their map confirms fairly high reported precipitation.

It was also a warm July. Not outside of one standard deviation on the temperature record going back to 1950, but slightly warmer (67.5F versus 66.24). It made me wonder if there was a trend of wetter Julies being warmer, too. Looking back through 1950, 19 of the wet Julies were also warmer than average. There were 30 wetter than average Julies and 40 warmer than average Julies. Maybe a trend of wet Julies being warmer, but it’s not guaranteed. I don’t think you can say much a warm Julies.

And now, a pause. The outlook for most of the next two weeks shows a drying trend with above average temperatures. More interesting is that the middle of the United States will see seriously below average temperatures. Enjoy the warm dry conditions while you have them.

6-10 day precipitation outlook from the Climate Prediction Center from August 4, 2017.

6-10 day precipitation outlook from the Climate Prediction Center from August 4, 2017.

 

8-14 day precipitation outlook from the Climate Prediction Center from 4 August, 2017.

8-14 day precipitation outlook from the Climate Prediction Center from 4 August, 2017.

 

 Posted by at 4:23 am

Another long break and a long delay to monsoonal flow to Flagstaff

 El Nino/La Nina, Lake Powell, Models, Monsoon, Northern Arizona Weather, Outlooks  Comments Off on Another long break and a long delay to monsoonal flow to Flagstaff
Jun 242017
 
The Partheonon at night, May 2017.

Yes, my last post was on May 4. Here we are several weeks, and European trips, later. Since May 4th, I have travelled to Prague, Greece, Italy, Austria and the far south of Germany. Prague was a work trip to see some stunning work presented! Greece was a week long sailing trip that came about because of the 40th birthday parties of a couple friends. Athens is truly striking! Italy was for a long weekend by the Gardasee (Lake Garda). Austria is in between, and with beautiful springtime green meadows against the rocky Alps. Ah! And now the weather!

The Partheonon at night, May 2017.

The Parthenon at night, May 2017.

Of course it’s fire season. I’m surprised by the number of fires and the intensity of the fire near Brian’s Head. It’s been a fairly wet winter and spring for most of the southwest. One of the indicators of this is the meteoric rise in Lake Powell. It is the deepest it has been on this date since 2011. It could be the second deepest summer out of the last decade. The lake hit it’s low point, just shy of 3594 feet in early spring. Currently, it is around the elevation of 3633 and still rising several inches per day. A wet year so far.

Lake Powell water level from water-data.com

Lake Powell water level from water-data.com. Notice it’s more like the last 5 years.

Now, the monsoon season. I realize there have been several faux monsoon storms. They were more driven by frontal systems passing to the north of Arizona, than a sustained moist flow from the south. The good news is that the heat has arrive to start the monsoon engine. Joe D’Aleo has written a nice summary of how the heat drives the flow. You can also take a look at my Monsoon Mechanics page.

The less good news is that the current computer forecasts point to the flow starting very much to the east of Flagstaff. It maybe after the 4th of July before the rains start in earnest. Below is a recent GFS model out look for precipitation between now and July 4. You can see only a small amount of precipitation predicted during this time frame.

Precipitation outlook between now and July 4, 2017 from the GFS model on TropicalTidbits.com

Precipitation outlook between now and July 4, 2017 from the GFS model on TropicalTidbits.com

Back to the better news, the outlook for the development of El Nino is low. El Nino conditions include the development of anomalous winds that can cut across the moisture flow, sending it elsewhere. Hopefully, when the season starts it will be a normal one.

Oh wait, what is a normal monsoon season?

 Posted by at 4:21 am

A different look at the numbers.

 Models, Monsoon  Comments Off on A different look at the numbers.
Sep 032016
 

I friend of mine reported heavy, torrential downpours in Flagstaff on Friday. This is typically good news. When I looked for the rainfall total at the Flagstaff Airport, the weather station had reported no rain for the day. When I looked at a couple of downtown weather stations, KAZFLAGS42 and KAZFLAGS82, on Wunderground.com, I found 0.57 and 0.32 inches reported. Location matters.

The Flagstaff area is subject to large variances in precipitation depending on location. Prevalent winds, changes in terrain and typography can all change the locally measured rainfall amounts. KAZFLAGS42 and KAZFLAGS82 reported 3.16 and 2.61 inches of rain for the month of August. Looking at Rainlog.org, the monthly self-reported totals are below, the variation is clear.

Rainfall totals from August 2016 on rainlog.org.

Rainfall totals from August 2016 on rainlog.org.

If you have lived in the area, you have experienced. In 1950, the the Weather Service movedFlagstaff weather station moved from downtown Flagstaff, to the current location at the airport. It still baffles me when the National Weather Service references historic data from before 1950. Here is their monthly summary for August 2016:

Monthly Temperature and Precipitation review for August 2016 from the National Weather Service in Flagstaff.

Monthly Temperature and Precipitation review for August 2016 from the National Weather Service in Flagstaff.

Notice the period the reference. It was cool and wet in August, but when you take measures from two different environments, equipment and measurement techniques, care is required making comparisons and claims. At a minimum, it should be made clear every time it is done. A more careful review for Flagstaff would include 1950 until present.

When considering 1950 to present, August 2016 was the second wettest, and tied as fourth coldest. Interestingly, since 2010, 6 of the 7 years have had rainfall above the 1950-present average. And, 3 of the last 4 years have been more than one standard deviation above the 1950-present average. Two of the last 4 years have been more than one standard deviation below the 1950-present average temperature.

 Posted by at 4:36 am

Second wettest August since 1950

 Hurricane, Record  Comments Off on Second wettest August since 1950
Aug 272016
 

With two days of record rainfall, 1.41 inches on Friday, 0.94 inches on Saturday, the total precipitation for August at the Flagstaff airport is 6.34 inches. Since placing the National Weather Service placed the weather station at the Flagstaff Airport in 1950, only August of 1986 had higher rainfall at 8.06 inches. This brings the 12 month precipitation over 26 inches, and the two-year total to over 52 inches.

The computer models keep projecting a drying trend, which never shows up. We’ll see what happens. I haven’t written in a while because the model outlooks have been in flux. Watching the potential development of tropical storms and hurricanes in the Atlantic has been very perplexing. Over the last week, one system has shifted between a band of organized thunder storms to a very powerful hurricane in and around Florida several times. Hurricanes, and forecasts of hurricanes, can affect the weather, and forecasts of the weather, for thousands of miles around. For some reason, there is a huge amount of variability in the computer models now. It will probably persist for the next few weeks as a very powerful storm is in the longer term outlooks.

 Posted by at 11:10 pm

Weather is always odd

 Models, Monsoon, Northern Arizona Weather, Outlooks  Comments Off on Weather is always odd
Aug 112016
 

As the most recent batch of moisture, which was left over from a tropical system, starts to leave Arizona, the outlooks have switched. We still have a dry period ahead, but then more moisture will return in about a week. At least, it looks that way today.

Yesterday, NOAA increased it’s outlook for Atlantic hurricane activity for the rest of this season. As if to point out who’s in charge, the computer models and Mother Nature removed any hint of future development in the next two weeks. Still, we are in the season and tropical activity can spin our monsoon season any which way. Hurricanes affect the weather for thousands of miles. With none in the plans, after the upcoming dry spell, thunderstorms should make a comeback.

To date in August, the Flagstaff Airport has received 2.32 inches of rain. an average or above average month is at hand. By comparison, Munich has received nearly 3 inches in August, and close to 11 inches in the last 30 days.

 Posted by at 9:35 pm

Don’t get too used to being dry

 Monsoon, Northern Arizona Weather  Comments Off on Don’t get too used to being dry
Aug 062016
 

With July finishing nearly on average for precipitation and over two inches falling already in August, the next few days should be mostly drier. But, don’t get used to it.

I think the current break in the action is due to a couple of tropical systems moving around Southern and Central Mexico. These have shutdown the flow of new moisture into Arizona. One Wednesday through Friday, some of their moisture and storm energy will move into Arizona. From the computer models, storms could double the current precipitation amount for August. The has been a consistent forecast for a couple of days now. We will see.

Beyond that, the monsoon flow looks shaky. For the calendar year and for the water  year, Flagstaff is well above average. This is interesting given how dry last winter was.

For those of you wondering, we have also had over 2 inches of rain in Munich this month. That’s on top of the nearly 7 inches of rain in July. Supposed to clear up today.

 Posted by at 9:52 pm

Strong precipitation outlook for the next month

 Models, Monsoon, Outlooks  Comments Off on Strong precipitation outlook for the next month
Jul 222016
 

The Climate Prediction Center released new 6-1o day, 8-14 day and 1 month outlooks on Thursday. Even though Flagstaff’s July precipitation is half of normal for this point in the month, the next month of the monsoon season should be above average. Below is an animation of these outlooks.

6-10 day, 8-14 day, and one month precipitation outlooks from the Climate Prediction Center (June 21, 2016)

6-10 day, 8-14 day, and one month precipitation outlooks from the Climate Prediction Center (June 21, 2016)

 Posted by at 8:40 am

After a long sigh, the monsoonal flow will return

 Monsoon  Comments Off on After a long sigh, the monsoonal flow will return
Jul 162016
 

It’s been chilly an draining in most of Europe for the last few weeks. It’s been warm and dry for a couple of weeks in Northern Arizona. Thunderstorm activity will increase over the next few days and hopefully continue for most of the rest of the month. I think I mentioned July 19th in my last post. This should be right on time. It’s going to change for Northern Arizona, but I don’t think it will change for Europe.

The southwesterly flow on the monsoon season is returning to Arizona. It looks like a return to normal, but I’m not sure it will be enough. Currently, July is 0.58 inches below average for the month to date. It looks like Flagstaff will receive over an inch by the end of the month. This would leave us short of the normal roughly 2.5 inches.

10 day total precipitation forecast from the Climate Prediction Center's GFS model.

10 day total precipitation forecast from the Climate Prediction Center’s GFS model.

 Posted by at 12:04 pm

Strong start, but now the monsoonal flow will stall

 Hurricane, Monsoon, Northern Arizona Weather, Outlooks  Comments Off on Strong start, but now the monsoonal flow will stall
Jul 022016
 

With over 1.25 inches of rain since June 15, Flagstaff has enjoyed a strong start to the monsoon season. However, that will change. A series of strong, Eastern Pacific tropical storms far to the south are going to distract the moisture flow. These storms are not going to head northward along the coast. The current forecasts have them moving to the west-northwest almost due north of Hawaii before looping back towards Washington State. After today, the changes for rain drop substantially. Isolated thunderstorms will start this week. By next weekend and through July 19, the chances for precipitation drop to nearly zero.

The Climate Prediction Center published a new 1-month outlook on June 30. It shows most of Arizona with better than normal chances for above average July precipitation.

 Posted by at 10:25 pm

Thunderstorm season to start early and with a boom

 Models, Monsoon, Northern Arizona Weather  Comments Off on Thunderstorm season to start early and with a boom
Jun 252016
 

We all know that the 4th of July is the typical “start” of monsoon season in Northern Arizona. So, anything earlier in my mind is early. As I sit in Munich and enjoy an even thunderstorm and a cool (not cold) weißbier, the computer models are telling me it is going to start very wet.

From the Climate Prediction Center, Friday’s 6-10 and 8-14 day outlook are strongly on the side of a very wet start to the season. Personally, I don’t believe they have the best record on monsoon forecasts, but I hope they are correct. And that they are correct because they have improved their modeling capability.

6-10 and 8-14 day precipitation outlooks from the Climate Prediction Center.

6-10 and 8-14 day precipitation outlooks from the Climate Prediction Center.

Here is the total precipitation forecast from their GFS model for the next 10 days. Notice some areas are to receive as much as 2-3 inches of rain.

I still worry that a strong start will result in a quick season.

gfs_namer_240_precip_ptot

 Posted by at 9:32 am
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