More agreement on White Christmas

 Models, Northern Arizona Weather, Winter Storms  Comments Off on More agreement on White Christmas
Dec 192016
 
Snow Miser (Christmas Specials Wiki)

Monday morning forecasts are tricky. Everything seems to change as people show up to work and pay more attention to what’s going on with the weather and the computer models. Still, this morning, there is more agreement between the GFS and Navy models.

The Navy model shows precipitation starting on Friday afternoon and lasting at least into Saturday. It may even last through the entire day. Also, the Navy model shows easily over half an inch of water. The storm appears to be a cut-off low pressure system. The Navy seems to do better at forecasting these. Their temperature model show relatively high snow levels. I think the precipitation is most likely to be snow.

6 hour total precipitation ending Friday evening, December 23, 2016. (US Navy NoGaps model)

6 hour total precipitation ending Friday evening, December 23, 2016. (US Navy NoGaps model)

The GFS model from the Climate Prediction Center shows a storm arriving later and producing but producing similar precipitation amounts. It also shows warmer temperatures through the day on Saturday. This would limit snowfall.

We’ll see what happens. Everything seems to change by Monday afternoon.

48 hour total precipitation amounts Ending Christmas morning,from the GFS model. (Climate Prediction Center)

48 hour total precipitation amounts Ending Christmas morning,from the GFS model. (Climate Prediction Center)

I used the image below as the featured image. Here is a link to the page that talks about the Snow Miser. It’s worth a read, and the TV show is worth watching. I think it sums up this upcoming storm.

Snow Miser (Christmas Specials Wiki)

Snow Miser (Christmas Specials Wiki http://christmas-specials.wikia.com/wiki/Snow_Miser)

 Posted by at 4:49 am

Navy says we may have a very White Christmas

 Northern Arizona Weather, Outlooks, Winter Storms  Comments Off on Navy says we may have a very White Christmas
Dec 182016
 
6-hour precipitation outlook from the U.S. Navy's NoGaps computer model for Friday evening, December 23, 2016.

I was feeling under the weather. Both because I have a cold, and the GFS computer model was not predicting any precipitation. Below is the 24 hour precipitation GFS model forecast for Friday, December 23, 2016. You’ll notice that the Arizona is covered in white, meaning no rain or snow. The rest of the intervening time has no snowfall predicted for Flagstaff.

24 hour total precipitation late Friday night, Dec. 23, 2016 forecast from the GFS computer model, via TropicalTidbits.com.

24 hour total precipitation late Friday night, Dec. 23, 2016 forecast from the GFS computer model, via TropicalTidbits.com.

So, I decided to check with the Navy to see if they thought the previously forecasted storm had vanished. They have a much different outlook for a similar time period. Their forecast below is for 6 hours, ending late Friday evening.

6-hour precipitation outlook from the U.S. Navy's NoGaps computer model for Friday evening, December 23, 2016.

6-hour precipitation outlook from the U.S. Navy’s NoGaps computer model for Friday evening, December 23, 2016.

This is a much different picture. The Navy has the precipitation starting on Friday morning and continuing through Saturday morning. If the Navy is correct, there could be significant snowfall during this time.

 Posted by at 6:29 am

Warm, wet storm Thursday to Saturday

 Winter Storms  Comments Off on Warm, wet storm Thursday to Saturday
Dec 142016
 

The temperatures for the approaching storm will keep the snow levels high, at least for much of the storm. However, the storm still could bring plenty of rain to Flagstaff, and snow to the Peaks. The best news is that it looks like there will be a storm track for the next couple weeks that will bring more light snow to the region.

Still, things can always change. Rain can become snow ahead of schedule. Be prepared.

 Posted by at 11:04 am

Did anyone order a White Christmas?

 Models, Northern Arizona Weather, Winter Storms  Comments Off on Did anyone order a White Christmas?
Dec 102016
 
6-10 and 8-14 day precipitation outlooks from the Climate Prediction Center, December 9, 2016)

I’m hoping I can bring some winter with me next weekend. And, it looks very much like I can. The jet stream shift continues in the computer models. The timing of the storm is Friday morning through Saturday afternoon. Here is the 24 precipitation total ending

24 hour total precipitation ending Saturday morning, December 17, 2016. (GFS Model from TropicalTidbits.com)

24 hour total precipitation ending Saturday morning, December 17, 2016. (GFS Model from TropicalTidbits.com)

I used the precipitation total instead of snowfall because the temperatures will most likely be warm. The snow levels will be higher than recent storms. As a result, the snowfall picture isn’t as pretty or colorful. With the warm temperatures and high precipitation amounts, the snow could be wet and heavy around Flagstaff.

But wait, there’s more. Looking beyond next weekend, the pattern continues to breakdown. A strong system may move up from the southwest and across Arizona during the week before Christmas. It’s still a long way off. Both events are leading to great 6-10 and 8-14 precipitation outlooks.

6-10 and 8-14 day precipitation outlooks from the Climate Prediction Center, December 9, 2016)

6-10 and 8-14 day precipitation outlooks from the Climate Prediction Center, December 9, 2016)

 Posted by at 1:29 am

Is this the picture for this winter?

 Models, Northern Arizona Weather, Winter Storms  Comments Off on Is this the picture for this winter?
Dec 082016
 
Jet stream forecast for Saturday morning, December 17, 2016. (Tropical Tidbits)

The jet stream is pushing storms mostly to the north of Arizona. Many strong storms have recently missed Arizona, but left snow and rain from Northern California to Colorado. Currently, the jet stream seems to be stable in it’s northerly trek. Notice the reds and purples in the image below. Will this be the trend for the whole winter?

 

Jet stream forecast for this weekend. (Tropical Tidbits)

Jet stream forecast for this weekend. (Tropical Tidbits)

I hope not. A storm has been dropping in and out of the computer models around December 17. The jet stream will drop south across the state and move a low pressure system across the state. This should be good news.

Jet stream forecast for Saturday morning, December 17, 2016. (Tropical Tidbits)

Jet stream forecast for Saturday morning, December 17, 2016. (Tropical Tidbits)

While it is good news, the current precipitation forecast is not very high.

24 hour total precipitation ending Saturday morning, December 17, 2016. (Tropical Tidbits)

24 hour total precipitation ending Saturday morning, December 17, 2016. (Tropical Tidbits)

It’s at least a shot at a change to a wetter pattern. I’m skeptical.

 Posted by at 4:13 am

Wonderful December Weather Ahead!

 Northern Arizona Weather, Winter Storms  Comments Off on Wonderful December Weather Ahead!
Nov 242016
 
Western US 5 and 10 day total snowfall GFS model prediction from Tropical Tidbits.

For those that follow me on Facebook, you will notice the posts about the spreading snow in Siberia and what it means for the rest of the Northern Hemisphere this winter. I think the key point is that El Nino overrides the impact early Siberian snowfall. But, we are heading towards La Nina this winter. It could be important.

Looking at the 6-10 and 8-14 day outlooks, Flagstaff could be on it’s way to a White Christmas. Below are the outlook maps for precipitation and temperature anomalies. With above average precipitation, and below average temperatures in the outlooks, snow it probably likely for the Northland. Also, the total snowfall prediction for 5 and 10 days from the GFS model at TropicalTidbits.com is shown. I think Flagstaff could be in the 10 inch range by day 10. This does not necessarily mean that 10 inches will be present on December 3, or anytime between now and then. Also, the general disclaimer about variations with altitude and particular terrain producing more or less precipitation apply.

If you like my post, please share it on Facebook (see the buttons above and below this post.)

Temperature anomaly outlook maps for 6-10 and 8-14 days from the Climate Prediction Center.

Temperature anomaly outlook maps for 6-10 and 8-14 days from the Climate Prediction Center.

 

Temperature anomaly outlook maps for 6-10 and 8-14 days from the Climate Prediction Center.

Temperature anomaly outlook maps for 6-10 and 8-14 days from the Climate Prediction Center.

 

Western US 5 and 10 day total snowfall GFS model prediction from Tropical Tidbits.

Western US 5 and 10 day total snowfall GFS model prediction from Tropical Tidbits.

 Posted by at 11:15 am

March to be a flip-flop of February

 Northern Arizona Weather, Winter Storms  Comments Off on March to be a flip-flop of February
Mar 012016
 

The outlooks and computer models are solidifying around a wet March. It starts this weekend with a mild storm with light precipitation. The pattern builds through the month. The precipitation in the first two weeks of March could hit the monthly average. More details as the future storms are closer. Below is the 6-10 day, and one month outlooks from the Climate Prediction Center.

6-10 day precipitation outlook from the Climate Prediction Center (1 March 2016).

6-10 day precipitation outlook from the Climate Prediction Center (1 March 2016).

One month precipitation outlook from the Climate Prediction Center (29 February 2016).

One month precipitation outlook from the Climate Prediction Center (29 February 2016).

 Posted by at 9:39 pm

It’s always just over the horizon.

 Northern Arizona Weather, Outlooks, Winter Storms  Comments Off on It’s always just over the horizon.
Feb 292016
 

The computer models keep dropping a significant storm into the long-range forecast. If you look at the image from my last post, it shows significant precipitation around March 4, 2016. The forecasts do point to some precipitation this weekend, but not the large amount in that image. The problem is that the big storm is always just over the horizon. Below is the outlook for Monday, March 14. It’s almost identical to the image in my last post.

As we move away from a very warm and dry February, we have to wonder if March will fulfill its historic reputation for the wettest time of year. The computer models keep pointing to a change in the storm track that will push storms over Arizona. We will see. Not much to blog about when it’s sunny and warm.

12-hour average precipitation rate (mm/hr) for Monday, March 14, 2016 from Tropical Tidbits.

12-hour average precipitation rate (mm/hr) for Monday, March 14, 2016 from Tropical Tidbits.

 Posted by at 8:48 pm
Feb 192016
 

Warm and dry has become the February story. The wet cold start has faded into sun and occasional high winds. There have be a few times the outlook was positive for wet conditions. It hasn’t happened.

Is it unusual for February to be dry during an El Niño winter. I think the data are pretty messy and there really isn’t enough to be very meaningful. Since 1950, the average for February precipitation in Flagstaff is about 2 inches. There are very wet and fairly dry Februaries during El Niño years.

Most of the areas that normally benefit from El Niños are benefiting this year. We continue to be way ahead on 12 and 24 month total precipitation.

The GFS model shows a possible weak storm at the end of the month, and a stronger storm at the start of March.

12-hour precipiation outlook ending noon, March 4, 2016. (Tropical Tidbits website.)

12-hour precipiation outlook ending noon, March 4, 2016. (Tropical Tidbits website.)

The 3 month outlook from the Climate Prediction Center continues to look positive from a precipitation point of view.

3-month precipitation outlook from the Climate Prediction Center.

3-month precipitation outlook from the Climate Prediction Center.

There is still time left this winter for more snow. March is typically the wettest month of the year. I think more is on the way.

 Posted by at 4:50 pm

Purplish Picture Present Promising Precipitation

 Models, Northern Arizona Weather, Winter Storms  Comments Off on Purplish Picture Present Promising Precipitation
Jan 292016
 

I’ve looked at a new site for computer model data. I think the pictures are prettier than the US Government site. No surprise there. The snow fall pictures are purple and orange for this weekend. It looks like the Flagstaff groundhogs will have a bit of digging to do to get to above the snow on Groundhog Day. In the image below, Flagstaff has a big 12 printed on it.

Three day total snow accumulation, ending midnight Monday night, February 1, 2016. (From TropicalTidbits.com)

Three day total snow accumulation, ending midnight Monday night, February 1, 2016. (From TropicalTidbits.com)

The colors are definitely more dramatic. The reaction to this storm from the National Weather Service hasn’t been until tonight. This storm is going to be big. It has shown up in the computer models as a big storm for a while. Just on Friday evening did they get excited.

There could be local effects causing the total to be more or less than the forecast. This is especially true with the windy start to the storm.

 Posted by at 10:11 pm
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