A Winter Set Up For A Summer Storm

A broad trough is off the California coast. A closed low comes onshore between LA and San Diego and opens up and moves toward our region. Then a negatively tilted trough develops as it approaches the Four Corners and opens up, bringing relatively large amounts of precipitation. Sound familiar? It should, that is how all good winter storms for our area come together. But, it is June 4th. Hmmm.

This should sound familiar too. The GFS is about 12 hours faster than the Euro. Both models are showing their biases. The GFS is always too fast–the Euro is usually a little too slow. The Canadian is going crazy overdoing the precipitation. You see, these models recognize the setup and are handling it just like it is a winter storm.

Depending on which model you believe showers could start late tomorrow afternoon or after 3 am Saturday morning. However, they could both be correct. The Euro struggles with these afternoon pop up showers, the GFS is for some reason more sensitive and shows them developing. So it could be that we see afternoon showers tomorrow afternoon unaffiliated with the closed low coming onshore. Another 18 hours of model runs should clear up the timing issues.

Precipitation totals vary widely but all point to amounts that will put us above average for June right out of the chute. Here they are as of today, they have been trending up about every run, it will be interesting to see how they look tomorrow at this time. These totals are through Sunday morning.

Euro

eurototal

German

Germantotal

GFS

gfstotal

Canadian gotta love it!

CMCtotal

Thanks for following. Check back in tomorrow at this time and we will take a closer look.

Click here to donate

Click here to contact

A Little More Action Today

Today we should see what the NWS would say is “an uptick in areal coverage” for thunderstorms which simply means chances are better that a larger area might be affected. The ingredients are mostly in place, increasing CAPE values and relatively high PWATs. Now we just need the sun to stay out long enough to get some decent heating and lift.

Here are the CAPE values throughout today and tonight. Remember CAPE just refers to the energy required for storms to develop, the higher the number the better the chances. Yesterday we were in the 700 range when the storms started developing.

Noon

nooncape

6 pm

6pmcape

An uptick around 8 pm

8pmcape

Next are the PWATs. PWAT stands for Precipitable Water, which just refers to how much liquid precipitation would accumulate if all of the moisture fell in one vertical column in one place.

Noon PWAT showing about 3/4 of an inch over DRO

NoonPWAT

7 pm tonight

7pm PWAT

10 pm tonight

10pm PWAT

You may not think .95″ is a lot for PWAT, however, the “average” PWAT for May 30th is approximately .31″.

If this pans out the way the model says we could get some rare nighttime rainfall. It looks like this pattern will continue for another 6 days, this is not monsoonal moisture, it is just an active pattern of weather moving disturbances under the ridge. We have at least another month before we will start to worry about the monsoon. Until then let’s just enjoy starting the driest month of the year with above-average (nonsoon) rainfall!

Click here to donate

Click here to contact

 

 

Apparently The GFS Got It Right

5 days ago I talked about the model differences as the Euro was showing hot and dry while the GFS was advertising afternoon showers from midweek on. It looks like another sunny day will give way to spotty mostly mid and higher elevation storms this afternoon with an even better chance tomorrow and Saturday.

The GFS is going a step further and saying that we are transitioning into a pattern of above-average precipitation over the next 10 days. We will see, but I am impressed and a little shocked that the GFS saw this 5 days ago. Obviously, if I would have bought into the GFS scheme I would have posted yesterday.

Yesterday the Euro didn’t see the pop-up storms until its morning run came out about 30 minutes past noon yesterday afternoon. It was enough to convince the National Weather Service to introduce “POPs” (probabilities of precipitation) in the point forecasts. At my house, they changed from mostly sunny to 60% chance of t-storms. In the end, I got about 5 drops of rain, but I did get a report from just across the highway at Lake Durango of a ten-minute shower. The point being these things will be very spotty and difficult to predict where they are going to set up. The GFS is showing a lot of activity for eastern La Plata County and all of Archuleta the next few afternoons. But don’t be surprised anywhere to see something pop up, especially above 7,500′ in the mid to late afternoon hours.

Hopefully, we will have more to talk about in the coming days.

Click here to donate

Click here to contact

 

 

The Future is Unclear

A trough and associated cold front will move through the state today. The only impact for our area today will be more wind and slightly cooler temps. Tomorrow moisture is going to get pulled into Colorado and how far east it makes it past the divide will determine who gets some precipitation.

If you are traveling to or through the northern and central mountains be ready for some snow tomorrow.

Here is the state snowfall forecast for Sunday and Monday.

GFS

gfs-deterministic-colorado-total_snow_10to1-0483600

Euro

ecmwf-deterministic-colorado-total_snow_10to1-0483600

For our areas, I don’t anticipate any meaningful precipitation, even if you are lucky enough to get a couple of drops of rain. Higher elevations and areas east of Durango and north of Hermosa have the best shot (albeit still a pretty low chance) of precipitation Sunday afternoon and Monday morning.

The models disagree after Monday. The GFS is showing some showers Wednesday, Thursday, and Friday. The Euro is exactly the opposite, building in a strong dry ridge with temps in the upper 80’s by late week.

If anything changes in the next two days I will post an update. Have a nice holiday weekend however you choose to spend it!

Click here to donate

Click here to contact

A Repeat Performance

I saw the NWS issued a freeze watch for tomorrow morning. They didn’t issue one yesterday for this morning. Tomorrow morning we should be a degree or two warmer than this morning. I saw some upper 20’s near Mancos this morning and at DRO.  If you don’t want to take any chances take precautions.

The models are still all over the place for Sunday/Monday. The Euro is now showing some light snow above 9,500 feet Sunday morning. I will do a more detailed update on Saturday morning, by then there should be some better consensus.

Click here to donate

Click here to contact

 

Borderline Cold Temps Tonight

I have had several requests to let people know when we are going to get some frost or freezing temperatures. Tomorrow morning there will be certain areas that will be threatened. If you have any concerns take precautions. I expect the coldest temperatures to be in the Mancos Valley over to Cortez. Pagosa and the southern valley areas south of 160 to the New Mexico Stateline including all of Montezuma, La Plata, and Archuleta counties. Again, if you don’t want to risk it, take precautions because it will be close to freezing in many areas.

At the moment the weekend looks pretty good, until Monday. I will keep you updated on that as we get closer.

Thanks for following!

Click here to donate

Click here to contact

Warm Then A Short-Lived Cool Down

As a potent trough of low pressure moves into California the next couple of days the ridge will move to the east, and the southwest flow will pick up driving temps in many locations into the low 80’s. The low will bring snow to the Sierra as well as parts of Nevada and Idaho. It will move to our north and Wyoming will get snow. We will see a temporary cooldown with temps back down into the upper 60’s in the lower elevations on Wednesday. Temperatures will gradually increase after that.

As far as precipitation goes the outlook is still bleak. The models were advertising some rain as the disturbance moves east to the north of us. But that is looking less likely in the current model runs. Unfortunately, the threat will be dry thunderstorms and gusty winds. I will be monitoring this and I will post if that comes to fruition. The first blip of moisture I see in the medium term is next Sunday (5/24) according to the Euro model. The GFS does not agree but it shows a minor disturbance by Wednesday the 27th.

Climatologically, May is our second driest month of the year, June is our driest month. We are still below average and will finish May below average in all likelihood by about .75″ inches in most areas.

I am not a big fan of comparing precipitation amounts to average during late spring and early summer. Below average is not unusual when the averages are so low. The weather pattern plays such a huge role it is not unusual at all to have very little precipitation here in April, May, and June. I would go as far as saying it is more common to have below-average precipitation than above-average precipitation. Why? Because the wet years are anomalously wet and they “set the curve”. If you look at the data for May for example, just over the last 30 years there are many years where we have had 0″-.3″ of precipitation, but every few years you will see totals up to 3.5″ that really inflates the “average” total. Holy crap, sometimes I even amaze myself at how much of a nerd I am.

So more of the same on the way, with a slight cool down on Wednesday. I will check in again before then to update on the potential for dry thunderstorms.

I have had a few people recognize the masked version of me in public and already ask about next winter. My money is on La Nina, but it is too early to talk about that. Don’t be fooled into thinking that La Nina by itself correlates to below-average snowfall. That does not apply here, El Nino, La Nina and neutral ENSO have less impact on San Juans than other parameters. As I said, too early to have that discussion today.

Thanks for following and continuing to support the site!

 

Click here to donate

Click here to contact

Monday Fun Day Update

So far we have been fortunate to have some precipitation reach the ground. The highest amounts have been east of 550 and north of Rockwood. From Hesperus to Durango roughly .05″ inches of rain have fallen. East of 550 and into the Bayfield area south of Forest Lakes an average of .10″ has fallen. North of Rockwood up to San Juan County, as well as Lemon and Vallecito, have seen up to .15″. This has had more of a psychological benefit than a climatological benefit. It felt good to wake to rain, but it is not going to a whole lot of good, unless, something changes later today.

There are two scenarios for this afternoon and it all depends on the sun. If we get a break in the clouds and the sun is able to heat up the surface it could be a very bumpy ride this afternoon with thunderstorms developing. If it stays cloudy there is still a chance of thunderstorm development, but they will be spotty and not as strong. I don’t know which is the better scenario. If we get some severe storms developing we could get some brief heavy rain and graupel in some areas.

According to the short term models that should happen. Here is the cloud cover model for this afternoon.

Here is 2 pm, it shows the cloud cover in the Durango area reducing to 40% and Montezuma County at 15%. In this scenario, storms would fire and move from West to East.

clouds1

Here is 3 pm, at this point, the model is predicting cloud cover in Durango falling to 19%, while Montezuma County is back up over 50%.

clouds2

The CAPE model falls right into place with this line of thinking.

Here are the max CAPE values at 1 pm.

mondayearlycape

And here are the max cape values at 3 pm, note the 1567 at DRO with some areas of La Plata County in 1800-2100 range!

monday cape

If this model is right the bumpy ride scenario will win out. You don’t need me or these models to help you plan. Just keep your eyes to the sky, if the sun is shining strong this afternoon, chances are we will get those storms.

Thanks for following. Montezuma County, since things would start their first (according to the models) let me know this afternoon if things fire up over there.

Click here to donate

Click here to contact

Something To Talk About

As boring as the weather has been here lately it has been pretty active in the midwest, north-central states and back east. Snow from North Dakota all the way to New York-a foot in some areas.

Yesterday was interesting because there were record highs and record lows across the US. Oddly enough, the biggest temperature disparity was in the Western US. While it reached nearly 110 for the high in Arizona, about 900 miles north in NE Utah the lowest temperature in the US was recorded when the overnight low was 7 degrees.

For our area, tonight and tomorrow bring the best chances of rain we have seen in a long time. For several days the models have been very consistent in bringing the rain and high elevation snow to break up the monotony of these dry sunny windy days. I wish it was that simple.

As good as the chances of precipitation are it is going to be spotty at best.  One of the methods used to predict rain is to look at Precipitable Water Values or PWATS. PWAT is a measurement of the total depth of liquid precipitation at the surface if it fell all at once.

There are a couple of ways to display this. First, there is the actual measurement.

Here is the PWAT at 3 pm today.

pwatsun3pm

Here it is at 6 am tomorrow morning.

pwatmon6am

What you should be thinking right now is: “Is that good or bad?”Good question.  We need to establish a baseline.  So I prefer to view PWAT as a percentage of the climatological average for this time of year.

Here is 3 pm today. This measures the PWAT anomaly (percentage of normal). Line up the colors with the chart on the bottom and you will see a range of 100%-150% of normal.

PWAT3pmanom

Now, look at 6 am tomorrow. Again line up the colors and you see a range in our area of 140% to 275% of normal.

PWAT 6amanom

And here is the animated version which shows the ranges from 3 pm today through 6 am Tuesday morning.

2NAMPWAT

The other thing to be on the lookout for with this approaching wave is surface-based CAPE. CAPE is just a measure of energy available to create thunderstorms. This region of the country pales in comparison to other areas of the country when it comes to CAPE. Over the last 12 years, any CAPE value in our area above 500 catches my eye.

Here is the CAPE forecast for 5 pm from the latest model run

cape5pm

Here is 8 pm from the latest run

cape8pm

But here was the same model 6 hours earlier. It shows 1564 at the airport and 2800 over downtown Durango!

06zcape8pm

The model run (in)consistency does not exactly leave me feeling warm and fuzzy. There is one more model run between now and 8 pm that I can look at and see which run it is closer to.

When I look at precipitation totals from the models they are not encouraging. They show most of the accumulations occurring in the higher elevations above 8,500 feet.

So what does all of this mean taken as a whole?  It tells me that most of the precipitation will evaporate below 8,000 feet before it hits the ground, despite the high PWATs. It also tells me that there is a chance of mostly dry thunderstorms. If you are new here, dry thunderstorms produce lightning, high winds, and very little rain. That is a deadly combination for fire danger. It also tells me to check back when the afternoon models come out. If the extreme CAPE values emerge again on the next model run I will do another post, if they don’t I will consider the older model run an outlier and I will post again Monday morning.

Thanks for following, happy Mothers Day to all of you Moms out there!

Click here to donate

Click here to contact

Monday Update

If you are enjoying the weather you will be happy to know that it should continue for the next week. Today will be just a couple of degrees cooler as a front passes to our northwest. The front was cold enough to generate snow showers on Loveland Pass and Vail this morning. Nothing like that for us!

Here are the results from the contest:

Karen Johnson won tickets to the San Juan Brewfest

Chuck Freeman won the $50 gift card to Nini’s

Bruce Rodman won the $100 prize

Wanda Cason won the $150 prize

Brooke Herb won the $250 prize

On Friday I posted a two-line update telling people to check their email. I didn’t have the donate/contact footer on it. I got an email telling me to put it back on because the person still wanted to donate. They also asked what percentage of followers actually donate. The answer is this year is approximately 2%. That is 4 times higher than last year, so thank you all for that, it is an honor to be a part of such a wonderful community!

Hopefully, I will some weather to talk about soon.

Click here to donate

Click here to contact