A Chance of Storms

With the ridge of high pressure dominating our weather lately, there has not been a lot to talk about. Yesterday afternoon there was a little instability in the atmosphere. That led to a couple of brief storms that trickled a little bit of precipitation to the ground in a few isolated areas.

Today the ridge will move slightly and allow an uptick in moisture over a wider area. CAPE (available energy) will be elevated. I expect a few storms to develop over the mountains today and stay intact as they move off of the mountains. Keep an eye on the La Platas and Hermosa Wilderness after 11 am for storm development.

Maximum CAPE values occur between noon and 2 pm in La Plata and Montezuma County and 4 pm in Archuleta County.  By 6 pm today the CAPE briefly rises again, this may be a model error, we’ll see.

2 pm CAPE

nam-nest-conus-colorado-cape-6312000

Here are the maximum PWAT values. PWAT is the total amount of precipitation in inches that could possibly accumulate if you are lucky enough to be under a storm today. The PWAT values also peak at 2 pm today.

nam-nest-conus-colorado-pwat-6312000

Tomorrow looks similar to today. Nonsoon conditions (orographic driven thunderstorms not related to the Monsoonal flow) will continue. Monday and Tuesday look drier. Wednesday and Thursday the models are hinting that we may tap back into Monsoon moisture from the SW. I have not seen enough run to run consistency to feel warm and cozy about this, but I will be tracking it.

One final thought, it is August 1st. First flakes usually fall at or above 10,000′ by the third week of September. My latest run of the long term Euro weekly model already shows snow in Colorado’s northern mountains by Sept 14th.

ecmwf-weeklies-avg-west-snow_46day-0041600

I know, it’s not much but as I post this once or twice a week it will be fun to see these totals grow. I know the next question you will have is “what are you expecting for this Winter?” It is too early to tell but it looks a lot like a weak to moderate La Nina is setting up. El Nino and La Nina are not good predictors of our Winter in SW Colorado. Other parameters that accompany those conditions are more important to us.

Thanks for all of the weather reports, and thanks for following!

Click here to donate

Click here to contact

Flash Flood Watch

The Monsoonal flow was well advertised. It arrived just when the models predicted and the precipitation amounts have been very close to what was predicted. Everything has gone pretty well, but as I mentioned a few days ago the monsoonal flow is going to take a break.

The ridge is going to pop back up and shut off the flow. I would expect some recycled moisture to hang out for a while leading to more isolated thunderstorms. We should see that downtick in activity beginning in the Wednesday/Thursday timeframe. Until then we will continue to see showers and thunderstorms, especially this afternoon and evening with scattered showers throughout the day on Tuesday.

The NWS released a Flood watch beginning at noon today.

/O.NEW.KGJT.FF.A.0002.200727T1800Z-200728T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SOUTHWEST SAN JUAN MOUNTAINS-ANIMAS RIVER BASIN-SAN JUAN RIVER BASIN-
INCLUDING THE CITIES OF IGNACIO, SILVERTON, DURANGO, BAYFIELD, RICO,
PAGOSA SPRINGS, AND HESPERUS
218 AM MDT MON JUL 27 2020

…FLASH FLOOD WATCH IN EFFECT FROM NOON MDT TODAY THROUGH MIDNIGHT
MDT TONIGHT…

THE NATIONAL WEATHER SERVICE IN GRAND JUNCTION HAS ISSUED A

* FLASH FLOOD WATCH FOR A PORTION OF SOUTHWEST COLORADO, INCLUDING
THE FOLLOWING AREAS, ANIMAS RIVER BASIN, SAN JUAN RIVER BASIN AND
SOUTHWEST SAN JUAN MOUNTAINS.

* FROM NOON MDT TODAY THROUGH THIS EVENING

* SCATTERED TO NUMEROUS STORMS ARE EXPECTED AGAIN ACROSS MUCH OF
SOUTHWEST COLORADO THROUGH THIS EVENING. STORMS WILL BE CAPABLE OF
PRODUCING LOCALLY HEAVY RAINFALL WHICH, WHEN COMBINED WITH SLOW
STORM MOTION, WILL ENHANCE THE RISK OF LOCALIZED FLASH FLOODING.
RAINFALL AMOUNTS OF HALF AN INCH TO TWO INCHES IN A SHORT AMOUNT
OF TIME WILL EXACERBATE FLOODING CONCERNS IN THE WATCH AREA.

* FLASH FLOODING WILL BE POSSIBLE OVER THE BURN SCARS AND AREAS THAT
HAVE SEEN SATURATED SOILS DUE TO PREVIOUS HEAVY RAINS. THE GROUND
IN BURN SCAR AREAS IS UNSTABLE, SO DEBRIS FLOWS AND MUDSLIDES
COULD OCCUR IN AND AROUND THE BURN SCAR.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD TO
FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION. YOU
SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION SHOULD
FLASH FLOOD WARNINGS BE ISSUED

Here are the latest model runs showing their precipitation accumulation predictions for the next 24 hours (ending 8 am Tuesday).

euro24

Canadian

gem-all-colorado-total_precip_inch-5948400

German

icon-all-colorado-total_precip_inch-5948400

GFS

gfs-deterministic-colorado-total_precip_inch-5944800

High-resolution NAM

Capture

Thanks for all of the spotter reports, I may not be able to answer all of them but I read them all. Thanks for following and for supporting the pages.

Click here to donate

Click here to contact

Showers Will Continue

The secondary push of moisture made it into the area as scheduled. Showers will continue throughout the day and should pick up in intensity again late this afternoon and this evening.

The models all agree the showers will continue, but they disagree on where the heaviest rain will fall. The high-resolution short term model has the heaviest rain falling in La Plata County, while the other operational models are trending further east with the heaviest rain falling in Archuleta County. NWS is favoring that solution. The German model is showing the heaviest rain accumulating near Navajo Lake.

Here are the various solutions from the latest model runs. These amounts are the total rain accumulation between now and 6 am Sunday.

NAM short term high resolution–definitely the outlier

nam

Euro

euro

GFS

gfs

Canadian

canadian

German

german

Thanks for all of the reports, and thanks for your support!

Click here to donate

Click here to contact

Weekend Outlook

It’s wet out there and it’s just what we have been waiting for.  Most areas either got some rain during the day yesterday or last night. I got reports of close to an inch in a few areas mostly north of town.

Today is a great example of what the Monsoon looks like. When the dew point is so high it limits the overnight cooling. This morning driving into town the temperature was 56 and the dewpoint was 56. That’s what causes the misty air–it is 100% saturated.

Today is another example of how the clouds will limit severe storm development to a certain extent. Showers will be scattered throughout the day and should increase this afternoon and evening. This air is moisture packed, but a secondary push of even more moist air will arrive just before this evening and could lead to heavy rain again in some areas. I would be very surprised if we make it through the weekend without flash flood warnings.

Saturday looks wetter than today as the reinforcing shot of moist air continues to stream in through the night and tomorrow morning. Sunday at the moment looks slightly drier, but I think it is too early to rule out more activity.

Next update on Saturday. Enjoy the moisture!

Click here to donate

Click here to contact

 

Is It Here Yet? Is It Here Yet?

Yesterday the clouds suppressed the convection from developing the storms we had hoped to see. There were several areas that did get some rain, but it was similar to what we have been seeing for the last week. The Monsoonal moisture tap seemed to shut down after it moved that initial surge into the area Tuesday evening.

Here was what the Euro showed yesterday morning, and it is why I said I was concerned with what I was seeing in Arizona.

Yesterday afternoon. Notice the lack of activity(depicted in green) throughout Arizona.

yesterday

Here is the same model today showing what to expect this afternoon. The moisture is further west than yesterday.

today

Here is what it expects tomorrow. You can see the heavier pockets make it up to our area and the coverage is more widespread.

friday

So for today expect another round of scattered showers. Some areas will be luckier than others. Tomorrow is a different story, at least that is what I am hoping for.

All of the models are predicting some very decent totals through Sunday afternoon.

Here is the German model which usually has a very dry bias in our area.

germsun

The Canadian

cansun

The Euro model

eurosun

And the GFS model which is very similar

gfssun

Impressive totals for 4 days!

Based on the 10-day totals it looks like the moisture tap will get shut down for a few days and then reappear later in the week.

10 day Canadian

can10

10 day Euro

euro10

10-day GFS

gs10

Next update on Friday. Thanks for your support and thanks for following!

Click here to donate

Click here to contact

 

 

Wednesday Update

Sorry for the late update. The usually reliable high-resolution model this morning had big problems. This is the first day in many months that I can remember it initializing so poorly. When I looked at it at 8 am it was so wrong it gave me nothing to work with. That’s what initializing means in model speak. If it is 8 am and the model says that at 8 am the entire county should be receiving heavy rain and it is not raining anywhere, that’s a problem. Interestingly enough, the model run from 6 hours earlier showed no rain until late this afternoon. The latest model run that is just now coming online is showing mostly scattered showers with activity picking up late this afternoon and through the evening.

I mentioned that I expected a cloudy day today. They have certainly been keeping the convection at bay. There is widespread disagreement among the models in regards to total precipitation accumulation between now and early Thursday.

I don’t see a lot of activity in Arizona, which is troubling because that is where things are supposed to be happening under Monsoonal flow. That being said the dewpoints in our area have been hanging around 50 degrees all day. That is humid for us. Yes, mid to upper 40’s % humidity is high for us in SW Colorado.

PWATs are going to top out at 9 pm tonight with 1.25″ at DRO. That is 225% of seasonal normal. PWAT refers to Precipitable Water Value–the total amount rain that could possibly accumulate if it all fell. CAPE, which is a value assigned to the amount of energy necessary for storm development, is supposed to peak between now and  5 pm. Storms usually lag the peak CAPE value time.

So we’ll see. At the moment it looks like tomorrow will be a little less favorable for heavy rain but Friday is looking really good as is Sunday through Tuesday. With the models struggling as this pattern changes who knows how accurate they will be.

I will try again in the morning. If I don’t have an update out by 10 am, it will be for the same reason I was late today. BTW the 10-day totals still look great, the usually conservative Euro model is off the charts right now with its prediction. I will do an update tomorrow on the 10-day totals.

Thanks for following!

Click here to donate

Click here to contact

Monsoon Update!

Before I jump into the weather I wanted to make a personal announcement. I have moved to a new Real Estate firm in town. It is a better fit for me and my business mix. I appreciate those of you who have come to me for your Real Estate needs. I always enjoy working with followers. If I can be of service click the contact button and I will respond and then you will have my email address.

July 21st And The Monsoon Is On The Way

11 days ago I told you that after the 21st, we would shift to a Monsoon pattern. Since I wrote that we have had spotty showers in the afternoon heating, a few areas have picked up a decent amount of rain, while others have been left high and dry. This is going to change.

This afternoon and evening we will see our first surge of subtropical moisture travel through Arizona and into the four corners. Tomorrow may very well be a cloudy day which will limit convection. However, the amount of moisture will eventually overwhelm the atmosphere and widespread showers should break out. As I type this (at about 10 am Tuesday) the dew point is 41 degrees. It will be interesting to see where it is in 24 hours. The old way of defining the Monsoon was multiple days of at least a 55-degree dewpoint. I still prefer this definition, rather than just declaring it Monsoon season on June 15th.

Here is the good part. Take a look at the 10-day rainfall projections.

Euro

euro10

GFS

gfs10

Canadian

can10

With the rain comes cooler temperatures. Here are the temperature anomalies below normal for the last 7 days of July (from this Friday to July 31st).

ecmwf-ensemble-avg-swus-t2m_f_anom_7day-5894400

I love being able to post good news like this! I am going to go back to daily posts starting tomorrow morning. Hopefully, with the widespread showers, I will be able to dial in on and highlight locations better than I have with these hit and miss showers.

As always, thanks for your support, and thanks for following me and referring new followers. Between the three mediums, I have surpassed 13,000 followers.

Click here to donate

Click here to contact

Monsoon-ish

I have been waiting all week for today and Friday because the models have been suggesting a decent shot of more widespread precipitation (rather than just the higher elevations). I was a little disappointed to see the morning model runs because they are not producing much in the way of widespread accumulations. Moist air has moved in from the southwest, bringing with it cloud cover, which we know can actually hamper the convection.

This moist air transport is close to what happens during an active Monsoon season. The problem is this is temporary. While it is Monsoon-ish, it is probably going to get shut down again before we see more favorable conditions in another week (fingers crossed). GFS is still bullish on this happening by the middle of next week while the Euro is holding off 4 or 5 days longer.

For today, the high-resolution model shows all of the ingredients we need for thunderstorm development.

Here are the max CAPE values (available atmospheric energy), they don’t occur until 3-4pm in La Plata County. They occur earlier in Cortez, Dolores, and Pagosa as well as the higher elevations above 9,000 feet.

nam-nest-conus-colorado-cape-4933200

Despite those high values, as I mentioned earlier, the models are not producing widespread accumulations. I do expect some areas to get caught under some decent rain, but the models are not helping me pinpoint where that will happen.

Here are the latest multi-model totals which take us to the end of the July.

Canadian

Capture

can360

Euro

Capture

euro360

And the bullish GFS. Remember the GFS is seeing a quicker pattern change than the other two models.

Capture

gfs36o

More important than the totals is where the accumulations are happening. When you see accumulations like this in southern Arizona and northern Mexico it is a good sign that the Monsoon season is trying to fire up.

Thanks for following and supporting the site. Thanks for all the great reports, it does help me “grade” the weather models.

Click here to donate

Click here to contact

A Slow Transition Ahead

Today there is a slight chance of a few storms developing, especially in the higher elevations. After a bone dry day yesterday, some moisture has started to filter in from the southwest. The models are showing a slight uptick in surface CAPE this afternoon. CAPE is the energy in the atmosphere necessary to develop thunderstorms. Here are the max CAPE values in Durango today.

CAPE at noon

nam-nest-conus-colorado-cape-4580400

500 is usually the minimum where you can see development. You can’t help but notice the values on the Front Range between 3000-5000. This means severe weather is nearly a guarantee.

A couple of parameters I don’t use for our area are fun to look at today with these very high CAPE values across the NE plains of Colorado.

Here is the Significant Tornado Parameter (STP or SigTor) for this afternoon. This is a multi-component index which combines many values (including CAPE) and determines the possibility of a F2 or higher tornado developing. It is similar to what the Weather Channel calls the “TORCON” index.

stp

Again, this is something I would never use in SW Colorado but it is fun (in a geeky way) to look at.

We are going to be slowly transitioning back to afternoon thunderstorms for the high country. These are not monsoonal, they are considered high altitude heat-based thunderstorms. They can but don’t always produce rain, a few of them occasionally drift off the mountains and remain intact over the lower elevations. Not monsoonal, not yet.

A couple of days ago I was talking about us easing into what appears to look like precipitation with more a monsoonal signature to it after the 21st. It is very difficult to track this pattern change, it always is. It usually defies the models. So the period after the 21st is just what I am seeing now, it could start earlier or later.

It is best to use a multi-model approach when looking that deep into the crystal ball. Here are the latest 15-day precipitation forecasts from the big three multi-models. The Euro is slowly coming around.

Euro DGO .44″, Telluride 1.55″ Cortez .24″

Capture

euro360

Canadian

Capture

cmc360

GFS

Capture

gfs360

If you are somewhere today where a storm develops let me know. Thanks for your support and thanks for following the site!

Click here to donate

Click here to contact

Dog Days Of Durango

I don’t hear the term “dog days of summer” anymore so if you are young you may not have heard it. It refers to ancient Greece when Sirius (the dog star) rose in alignment with the sun and they believed it contributed to the heat this time of year. The period lasts from roughly the end of June to the end of July. Of course, this theory was proven false many years ago.

I have been very busy this week, and there has not been a lot to talk about so I have not posted. If the weather was more active I would have found the time to keep everyone updated.

The short term looks very hot and very dry. Saturday and Sunday we should see the hottest temperatures of the season. Saturday we will see mid to upper 90s below 7,000 feet. Mid elevations will reach the lower 90s and Purgatory may reach the upper 80s.

A large trough will be coming onshore which may trigger some convection Sunday afternoon. At this time I don’t see any chance of rain reaching the ground with the exception of mountain ridge tops.

It looks like we will be locked in this pattern until around July 21st. Several long-term models show us evolving into a more moist pattern.

Here is the long term Canadian multi-model run showing the 7-day precipitation total ending July 25th.

Capture

cmc

 

Here is the same data run from the US GEFS multi-model.

Capture

gfs

The Euro also picks up on the trend but it will be a couple days before we can track the same period because its model does not have as long a term of run time. What is encouraging here is that if you look at where the precipitation is accumulating you can see that it appears to a monsoon signature to it. What is also encouraging is that all of the models are picking up on it.

So hang in there, it takes a lot to break a dry pattern or a wet pattern because soil moisture results in feedback. In other words, dry soils inhibit moisture and wet/saturated soils encourage precipitation. Thanks for your support and for following I will update again on Sunday

Click here to donate

Click here to contact