Stu

Jul 032014
 

Dew point temperatures across Arizona will move higher over the next few days. This means more widespread thunder showers across the area. A friend of mine, TB, was mentioning his plans to hike around one of the creek beds near Sedona for the 4th of July. Flash flooding is a serious issue in the desert. Here are some flash flooding safety rules from the National Weather Service (in Ohio?):

  1. In hilly terrain, flash floods can strike with little or no advance warning. Distant rain may be channeled into gullies and ravines, turning a quiet stream into a rampaging torrent in minutes. Never camp on low ground next to streams since a flash flood can catch you while you’re asleep.
  2. Do not cross flowing stream on foot where water is above your ankles.
  3. If you are driving, don’t try to cross water-filled areas of unknown depths. If your vehicle stalls, abandon it immediately and go to higher ground. Rapidly rising water may sweep the vehicle and its occupants away. Many deaths have been caused by attempts to move stalled vehicles.
  4. Be especially cautious at night. It’s harder to recognize water danger then.
  5. Don’t try to out race a flood on foot. If you see or hear it coming, move to higher ground immediately.
  6. Be familiar with the land features where you live, work, and play. It may be in a low area , near a drainage ditch or small stream, or below a dam. Be prepared!
  7. Stay tuned to NOAA Weather Radio for the latest statements, watches and warnings concerning heavy rain and flash flooding in your area, report it to the National Weather Service.

I’m bugged by the fact that a quick search for “flash flood” on the NWS Flagstaff website didn’t turn up a document like this. Something that isn’t stressed in this list that is very important is that the storm can be far away and cause a flash flood where you are. Be aware of the weather upstream from your location. A small creek bed can be the sole drainage for hundreds of thousands of acres. If you are in a canyon, you may not be able to even see the storm. They do have a good webpage set up for monitoring the area around the Slide Fire.

Here is the North American Mesoscale precipitation model outlook through midday on Sunday.

Total precipitation from July 3 to July 6, 2014 from the North American Mesoscale Model at the Climate Prediction Center.

Total precipitation from July 3 to July 6, 2014 from the North American Mesoscale Model at the Climate Prediction Center.

 Posted by at 6:50 am
Jun 262014
 

The 8-14 day outlooks continue to look wet. Thursday, the 6-10 Day outlook from the Climate Prediction Center looks wet, too. This 6-10 day outlook includes July 2-8. The signs are good for a change to the monsoonal flow next week.

8-14 day precipitation outlook from the Climate Prediction Center, June 26, 2014.

8-14 day precipitation outlook from the Climate Prediction Center, June 26, 2014.

6-10 day precipitation outlook from the Climate Prediction Center, June 26, 2014

6-10 day precipitation outlook from the Climate Prediction Center, June 26, 2014

 

 Posted by at 1:08 pm

Wind forecast fades

 Monsoon  Comments Off
Jun 252014
 

I think the winds have taken a bit longer than usual to fade so that the monsoonal flow could begin. The winds have been strong and out of the west to southwest. Finally, the wind outlook shows the strength dropping through this weekend and swinging around to the south to southeast by early next week. Here is a graph from Wunderground.com showing the decrease in wind speed.

7-day graphical weather forecast from Wunderground.com.

7-day graphical weather forecast from Wunderground.com.

This next image is from this morning’s 10-meter wind outlook from the GFS model at the Climate Prediction Center. The forecasted wind direction is from the southeast.

10-meter wind and precipitation outlook for Monday afternoon, June 30, 2014 from the Climate Prediction Center.

10-meter wind and precipitation outlook for Monday afternoon, June 30, 2014 from the Climate Prediction Center.

 

 Posted by at 12:06 pm
Jun 242014
 

Well, the Climate Prediction Center has made a major shift in its 8-14 day precipitation outlook. Yesterday, most of Arizona moved into the above average precipitation zone for the 8-14 day period.  This period starts on July 2. This is very positive news of a wet and timely start to the monsoon season.

8-14 day precipitation outlook from the Climate Prediction Center (June 24, 2014)

8-14 day precipitation outlook from the Climate Prediction Center (June 24, 2014)

 

On June 23, 2014 the outlook had Arizona in the normal zone. This time of year, normal can mean wet or dry. On June 19, 2014, the outlook was for drier than normal conditions.

8-14 day precipitation outlook from the Climate Prediction Center.

8-14 day precipitation outlook from the Climate Prediction Center (June 23, 2014)

814prcp.20140619.fcst

8-14 day precipitation outlook from the Climate Prediction Center. (June 19, 2014)

 Posted by at 5:55 pm
Jun 192014
 

The good news is that most of Northern Arizona remains in the above average precipitation zone for the summer. Still, I don’t believe El NiƱo is the link. There are a combination of factors. The Climate Prediction Center issued a new 3-month outlook last week.

20140619-200139-72099503.jpg

The bad news is that the winds may not leave for another two weeks. The winds we have experienced lately are due to the jet stream moving far to the south. It would have been a blessing in the winter. But now, it delays the monsoon season.

 Posted by at 11:09 am
Jun 112014
 

The Arizona Daily Sun published this article over the weekend: Forecasters: Wet Summer and Winter likely in Flagstaff. This article hints at El Nino as the cause for both extra rainfall this summer and more snow next winter. About a month ago I started to look into El Nino’s effects on Flagstaff’s summer precipitation. My hypothesis was that El Nino actually lowered rainfall amounts in the summer.

Digging into the data since 1950, there really isn’t much difference between the over all normal for 1950-2010 and any of the El Nino averages based on the strength of the El Nino. There are huge swings in the summer (June-September) rainfall amounts. Just to make the point, The El Ninos of 1957 and 1982 are both strong. They produce 4.81 and 13.42 inches of rainfall. The El Ninos of 1986 and 1991 are both moderate strength. They produced 20.64 and 3.53 inches of rainfall. The weak ones are all around 7-8 inches of rain. It looks like anything goes with El Nino Summers.

There is more than just El Nino driving the events for the year. The Climate Prediction Center still has Flagstaff in the above average rainfall zone for the summer. They should have an updated model later this week.

On a side note, I noticed last night that AccuWeather.com had a thunderstorm in the long-range outlook for Flagstaff on June 24. It’s gone this morning.

June July August September Total
El Nino average 0.41 2.33 3.02 2.11 7.87
1950-2010 average 0.43 2.4 2.89 2.12 7.84
Strong El Nino Average 0.86 1.78 2.37 3.22 8.22
Moderate El Nino Average 0.28 2.59 3.38 1.72 7.97
Weak El Nino Average 0.15 2.42 3.05 1.61 7.23
1950-2010 average 7.7
 Posted by at 7:01 am
Jun 102014
 

It’s still nearly a week away, but next Sunday and Monday could be rather wet if the US Navy NoGAPs forecast is correct. This storm doesn’t show up in the GFS forecast, but there is something weak in the Global Ensemble forecast. We will see.

US Navy NoGAPs computer model for Sunday afternoon June 13, 2014

US Navy NoGAPs computer model for Sunday afternoon June 13, 2014

 Posted by at 6:35 am
May 252014
 

With a fire at this time of year, it’s natural to look at the calendar and think about how long until monsoon season, and will it be a good one. The Climate Prediction Center has Flagstaff inside the above normal region for the June-August and the July-September 3-month precipitation outlooks(see below). The current June outlook has us at even chances for normal precipitation.

A particularly interesting part of the monsoon season is Eastern Pacific hurricanes and tropical storms. These can bring exceptional moisture to Arizona. Hurricane season for the Eastern Pacific start on May 15th. Hurricanes do not usually form in May in this region, but they can. If they do form, they usually wander around the coast of Southern Mexico or drift straight out to the west. This year, we have our first storm, Hurricane Amanda. The computer models show Amanda moving up the West Coast and bringing moisture to Arizona by late in the week. It is still 5-7 days out, but it could at least help keep our temperatures lower and out humidity higher for a while.

One last note: The Climate Prediction Center issued an El Nino watch. The current outlooks show a strengthening El Nino that could be quite strong for next year. My current question is whether this could derail our monsoon season.

3-Month precipitation outlook for July, August and September from the Climate Prediction Center.

3-Month precipitation outlook for July, August and September from the Climate Prediction Center.

3-month precipitation outlook from the Climate prediction Center for June, July and August.

3-month precipitation outlook from the Climate prediction Center for June, July and August.

 Posted by at 4:55 am
May 242014
 

I haven’t posted for nearly a month. There are a couple of reasons for this. One is that dry, windy conditions just aren’t that interesting. Their normal for this time of year and we should expect it. Second, I have had a couple of long international trips in the last month. One for business. One for pleasure. I’m thinking about moving the blog to WordPress.com, or Wunderground.com. It would save me some money and time. We’ll see.

I thought about blogging about the Slide Fire over the last few days, but haven’t for two reasons. First, I drove to Phoenix for work on Tuesday night. So, I haven’t experienced the events related too it. It sounds quite uncomfortable. Ash falling from the sky and smoke filling your lungs must stimulate our most basic survival instincts. Second, I couldn’t make heads or tails out of what was really happening. A particular friend provided the clearest details. But, on Wednesday, I heard conflicting stories about Kachina Village all day long. As well, I couldn’t figure out where to point people for the best information on the fire. I’m still wondering today.

I think the Inciweb site for the Slide Fire is the most up to date, but even this morning the most recent update is 12 hours old. And, that update doesn’t add much information.

Good news, bad news. Good news, temperatures and winds have dropped while moisture has increased. Bad news, this could cause thunderstorms. These thunderstorms may produce lightning without much rain. That could cause more fires in the area.

Hats off to the teams fighting the fire. Seems like this could have been much worse. Their skill and courage protect us.

 Posted by at 8:33 am
Apr 252014
 

This weekend will be another cooler, wetter weekend. The precipitation forecast in the North American Mesoscale model shows Flagstaff in the one-half to three-quarters of an inch of precipitation zone. This could be the most significant storm in months. We should see mostly unfrozen precipitation, but if temperatures are low enough, some very temporary snow accumulation is possible.

North American Mesoscale model precipitation outlook through Sunday morning. From the Climate Prediction Center.

North American Mesoscale model precipitation outlook through Sunday morning. From the Climate Prediction Center.

 Posted by at 6:37 am
6 visitors online now
2 guests, 4 bots, 0 members
Max visitors today: 16 at 12:28 am MST
This month: 16 at 09-01-2014 12:28 am MST
This year: 20 at 07-13-2014 08:41 am MST
All time: 1611 at 04-27-2012 06:53 pm MST

Social Widgets powered by AB-WebLog.com.