Wednesday, January 29, 2014

It's January But Has Seemed Like Spring

I have been tied up on a special project but am taking a break to get a blog post up.

The last two weeks have been very warm during the days, even though lows here at house have been mostly in the 20s. The flora and fauna seem to be responding to the afternoon temperatures, and it has seemed like spring when I've walked along the Rillito. Small, brown ground squirrels have been out of their burrows and active. Saw two large hawks carrying small limbs to work on their nest high in a gum tree. There was a large collared lizard out and about here at the house this week, Yesterday I saw a brilliant, bright vermilion flycatcher down at the nearby park - a stock photo of one of these is below.

A mourning dove has been nesting on top of the garage door opener for a week or so and she's sitting on two eggs. I gave up several years ago fighting them to keep them from building a nest up there and just set up a box for them. Photo below is of a small bougainvillea just down the street. These colorful plants have usually frozen back to the ground by this time of the winter (at least in this cold part of town). The wall faces south, so it's a warm spot.

As for the weather there are finally some changes after almost six weeks with the 500 mb ridge anchored right along the west coast. Several short wave have been breaking through underneath the ridge and setting up a southern wave-train beneath the persistent anticyclone centered over Alaska. Above is GFS ensemble average at 500 mb valid at 12 UTC tomorrow morning (January 30th). Below is the same graphic but valid at 12 UTC on February 5th. The anticyclone continues intense and anchored over Alaska, with a Rex Block pattern sort of set up by then. Note the ridge-line over the east Pacific has backed off some to the west. So, if we can get some moisture with one of the waves in the southern stream we just might see some weather return to the Southwest.

Saturday, January 25, 2014

Trace Of Rain Early This Morning

There was a sprinkle here at the house this morning, Saturday, January 25th) sometime between 4 and 5 am MST. Composite radar image from NWS above is from a bit after 5 am. The trace of rain here is the first hint of rain since December 20th, 2013. Main impact has been a wonderful smell of moisture in the air.

Friday, January 24, 2014

High Overcast, Dirty Skies And Mild Temperatures

View of Catalinas at 8:20 am MST above shows high cirrus overcast and skies a bit dirty with dust from the east. Winds are currently gusting over 30 mph at the airport. Morning temperatures have been quite mild with a low so far at the airport of only 52 F - here at house temperature had dropped to 41 F before the winds broke through. MesoWest surface plot at 6 am (below) shows mild temperatures across the Tucson area and gusty east winds at many locations. The WRF forecast models run at Atmo yesterday forecast the winds and temperatures quite well for this morning.

An upper-level short wave is moving north just west of Baja (IR image from 13 UTC below) with widespread cloudiness associated with it, including the cirrus currently over Tucson - note that airport ASOS indicates clear skies since the system does not detect higher clouds.

Thursday, January 23, 2014

Backdoor Cold Front Heading Our Way

Edited at 2:30 pm MST 23 January - current MesoWest surface plot above shows that the backdoor cold front has just come across the border into southeastern Arizona.

Surface plot from 5 am MST this morning (above) indicates a strong cold front that is heading westward across New Mexico and approaching El Paso, Texas. There is more than 20 mb difference in SLP between El Paso and the Oklahoma Panhandle, where temperatures are in the single digits. This front will backdoor into southeastern Arizona during the night, bringing a period of strong easterly winds and more bouncing temperatures. The early WRF-NAM forecast this morning (23 January) brings the front across the Tucson area around midnight tonight and forecast 10-meter winds are strongest around and after sunrise tomorrow. The 10-meter wind forecast below is valid at 8 am tomorrow morning. But I am thankful that I'm not in  Illinois or Wisconsin this morning where the winds and below zero cold are brutal.

Tuesday, January 21, 2014

GFS Ensemble Forecasts - Finally A Bit Of Hope

For the past month we've lived under the 500 mb ridge here in Tucson with mostly clear and dry skies, cold mornings and warm afternoons. Above photo of Catalinas yesterday (Monday, January 20th, MLK Day) afternoon shows the weather highlight of the day as some contrails zipped by.

However, last evening's runs of the GFS ensemble forecasts hold out some hope in the longer term. The three panels below show the 500 mb average heights and anomalies forecast at 84-h, 156-h, and 228-h. The bottom panel is valid at 12 UTC on Thursday, January 30th. The west coast ridge remains extreme through 7 days but then, by the end of the month, a trough from the Pacific plows through the ridge and weakens it dramatically. It's a long way out but we can hope that it's got the trend right.

Saturday, January 18, 2014

Rosemont, SSSR, And Important Exhibit

Off topic again but more information related to the proposed Rosemont copper mine.

Life In The Ridge - Big Diurnal Swings

More wintertime C of C weather in Tucson. View of Catalinas this afternoon (Saturday, January 18th) with a few wisps of cirrus scooting by. The string of consecutive days with lows of 30 F and colder continues here at the house and has now reached 14 days. Lows last four days were 23 F, 26 F, 24 F and 27 F today. Lows here and highs at TUS show diurnal swings of 50 F on Wednesday and 53 F yesterday. Cold mornings and gorgeous afternoons.

Tuesday, January 14, 2014

More On The Bouncing Temperatures Across Metro Tucson

Edited to add verification on January 15th - the WRF model was considerably too warm in its forecast of morning lows since the east winds went mostly calm across the metro area after about 2 am. Winds at high elevations blew through the night from the east and lows were considerably warmer at the higher elevations.

Verifications re post below: TUS WRF 51 F NWS grid 37 F actual was 34 F; DM WRF 49 F NWS grid 38 F actual was 36 F; house WRF NA NWS grid 39 F actual 23 F. So only part of my discussion that turned out accurate was that relative to here at the house, where the string of very cold mornings continues.

Lows this morning were very cold here in the north part of the city of Tucson and it was 23 F with another frost here at the house. But down at the airport and also DM AFB the lows were 35 F. The WRF-NAM forecast from 12 UTC this morning continues to forecast much warmer temperatures tomorrow morning (Wednesday, January 15th).

Table above shows WRF forecast lows for tomorrow morning with the range over Tucson metro from about 45 F to 55 F. Forecast low for airport is 51 F, which is 16 F warmer than this morning. The warmer low temperatures are due to the easterly winds that the model forecasts to persist during the night - below is the WRF-NAM forecast of 10-m winds valid at 4 am MST tomorrow morning. The latest NWS grid point forecasts for morning lows are: TUS 37 F; DM 38 F; and house 39 F. Since the forecast winds are marginally strong, the model will likely be too warm. The NWS gridpoint lows at the airport and DM may be too cold, but will probably be too warm here at the house. So a very difficult temperature forecast situation.

Monday, January 13, 2014

Cold Mornings And Life Under The Ridge

The past week we have mostly been under the 500 mb ridge, or under the influence of very week disturbances passing by mostly to the north and northeast. With mostly clear skies, the last 9 mornings have been quite cold here along the Rillito. The morning lows have ranged from 21 F to 30 F each morning for these 9 mornings - with 21 F on the 6th to 30 F on the 8th - this morning (Monday, January 13th) coming in with frost and 26 F here at the house.

I took a look at the WRF-NAM early run to see whether the model forecasts strengthen the easterly winds, as high pressure dominates over the southern Plains and the Southwest. The early WRF-NAM does forecast easterly winds increasing to 15 to 20 mph over parts of the metro area tomorrow night (Tuesday, January 14). because of this the model forecasts (see graphic below) the low temperatures to be bouncing around again. For tonight the model forecasts low temperatures west of the Catalinas to be around 10 F warmer than down at the airport. However, the forecast lows for Wednesday morning are generally 5 F or so warmer, but with the airport warming by 11 F. The string of consecutive days below freezing here at the house may continue for a few more days (it tends to go calm and stable here many nights when the winds blow at TUS and Davis-Monthan).

The GFS-ensemble forecasts for 500 mb are shown here with averages on left and spaghetti plots on right - above is at 84-hours (valid 12 UTC on Thursday) and below is at 168-hours (valid 00 UTC next Monday). We basically remain under the ridge through the next week. By the end of the week the GFS spread is greatest again over the Southwest, as a number of weak 500 mb short waves are forecast to break through into the southern part of the ridge. Little weather to talk about - cold mornings some spots, mild afternoons, and continuing drought.

Friday, January 10, 2014

The USFS, Augusta Rosemont, And Visual Subterfuge

I am going to go off topic for awhile, since the southern Arizona weather situation remains fairly benign.

The USFS has published a Final Environmental Impact Statement (FEIS) for the proposed Rosemont, open-pit, copper mine that would be mostly sitting on public lands of the Coronado National Forest. Since I filed comments on the draft statement (DEIS), I was able to request a hard-copy of the FEIS. The multiple volumes arrived via UPS in a 17 lb shipment! However, the USFS seems to have avoided responding to most of the comments that were technical and/or scientific in nature (there were over 25,000 comments submitted in reaction to the DEIS).

Many members of the Tucson Chamber of Commerce are supportive of the mine going in, even though public lands will be destroyed, the number of jobs related to the mine's estimated life will do little to invigorate the economy of southern Arizona, and pollution will increase as air and ground water quality degrade. The profits from the mining will go to a Canadian company (Augusta Resources Corporation - Rosemont Copper) and the copper produced will mainly go to Asian countries along the Pacific Rim. More on the pros and cons of this project are at       

The local business weekly, Inside Tucson Business, headlined its December 20th (2013) issue with "120 Days To Go (Maybe) - Forest Service gives tentative OK to Rosemont mine." The article led off with a photograph that showed a USFS simulated image of what the mine would look like from mile marker 46 on Highway 83. It is a fairly benign and dry image with the mine tailings and pit just peeking over the intervening hills. However, this image was not one for the actual proposed mine that the USFS has given its tentative OK.

The project area is along the east flanks of the northern end of the Santa Rita Mountains (an ecologically diverse Sky Island) and west of state Highway 83 (a state of Arizona designated scenic highway). The project region experiences a summer rainy period that produces a dramatic greening during the monsoon period, due mostly to the rapid growth of grasses and leafing mesquite trees (the junipers and oaks on the site hold much of their color through the dry seasons). However, most photographs depicting the project area (i.e., by the USFS, Rosemont Copper and its consulting companies) are from dry times of the year, never showing (purposefully?) the natural summer beauty of the site.

The following collage is of USFS photos and simulations and also photographs I took from various spots along and west of Highway 83. The photographs I took are from mid-September 2013, as the summer monsoon was winding down.

The above is a USFS current photo from mile marker 46 (at the far northeast corner of the Rosemont Project area - near the USGS stream flow gauge in Barrel Canyon) paired with a simulation of the same view when the planned mine would be in operation.. Below is a similar pair of photos for mile marker 44 - there is a scenic overlook at this mile marker, but there will certainly be nothing scenic here if the mine is completed. Note that all of these are depicting the scenes when it is dry and the grasses are dormant.

I shot the photo above (on September 13, 2013) looking west from the mile marker 44 scenic turnout. The grasses are knee-high, or taller, and most of the land not covered with trees is covered with grasses (a few exposures on ridges are mostly barren and the steeply sloped mountains along the west edge of the project area are abrupt and bare rock).

I then headed south and took a dirt road into the eastern portion of the project area. The photo below was taken within the project area and in this part of the project area the arroyos are filled with mesquite and juniper trees because of the higher elevation and more annual rainfall than at the lowest elevations.

I continued south again on 83 and the photo above is at a higher, and wetter elevation, where the arroyos are filled with beautiful live oak trees and interspersed deep grasses.

It shouldn't be a surprise that a very high percentage of the ranches and properties with the entire general area of the proposed mine are currently offered for sale. The signs shown below are just off the southeast corner of the Rosemont project area - the trees are again large, live oaks.

The project area slopes upward from northeast to southwest, producing a strong gradient of annual rainfall. The state-of-art, high resolution PRISMS system (developed at Oregon State for application to complex terrain) yields 30-year estimate of annual rainfall on the project area that ranges from 21 inches per year near the stream gauge to over 25 inches along the ridge at the southwest edge of the project area. The character of the summer surface and vegetation shown in these photos reflects this strong gradient in annual rainfall across the project area.

Finally, this simulation of the mine at full capacity (below) is what Arizonans who support this project would leave to their children and grandchildren.

Yesterday Really Fizzled

What did Thursday, January 9th bring to the Tucson metro area? Not much. High cirrus (above at 11 am MST) during much of the day, but with nice clearing by 5 pm (below). So the global models were really a bust until right before the event. So it goes.

Wednesday, January 08, 2014

Models Still Bouncing Around Re Tomorrow

The situation this morning provides a nice illustration of how, at times, the latest forecast models can be inconsistent at very short time frames. The reasons for this situation today appear to be the varying, in time, and weakly defined initial conditions off the northwest coast of the U.S.

First I'll show forecasts from the early (midnight) runs of the high-resolution WRF model at Atmo. The forecast of composite radar echoes from the WRF-GFS valid at 3 pm MST tomorrow afternoon (Thursday, January 9th) is shown above, indicating light showers and rain just brushing the southeast corner of Arizona. The same forecast from the WRF-NAM is shown below and indicates a widespread area of light showers and rain across all of the eastern half of Pima, extending east and northeastward into other parts of southeast Arizona.

Products from the NWS model forecasts used to initialize the early WRF runs are shown here. The forecast is of accumulated rainfall through midnight Thursday night (note the darkest green indicates amounts of 1/4 to 1/2 inch). Again there are substantial differences over southeast Arizona, which would be expected given the difference in the two versions of the WRF forecasts.

Finally, to further confuse the issue, the new runs this morning of the NWS NAM model have done an about-face for southeastern Arizona. The new NAM forecast of accumulated rainfall through midnight tomorrow is shown below - quite different than the earlier version just above.

So, what exactly will happen over Pima County tomorrow? Definitely increased cloudiness, but the chances of rain or showers at low elevations are likely to not be very great, since the main impacts of the amplifying short-wave will be off to the east of the Continental Divide. But, this is a situation where we'll have to wait to see what tomorrow brings.

Tuesday, January 07, 2014

Showers On Thursday?

First, a quick look at some low temperatures, which have been bouncing all over the place inside the City of Tucson. Yesterday morning it was very cold here at the house, with a moderately heavy frost. Low temperature hit 21 F (versus 32 F at TUS and 33 F DM AFB). Winds here went calm again last night and the low dropped to 23 F, but east to southeast winds during the night kept south portions of the city considerably warmer. Low at airport was about 39 F, while DM remained even warmer at 45 F.

The models forecast a chopped up 500 mb pattern over the Pacific to evolve into a strengthening short wave over the Southwest by Thursday this week. However, there remains considerable variance among the various models, even at the relatively short-term, 72-hour forecast time. The GFS ensemble forecasts at 500 mb (from 00 UTC last evening) are shown above valid at 12 UTC on Friday, January 10th. The uncertainty in the ensemble forecasts is small, except over Arizona and the Southwest.

The new NAM forecasts this morning forecast little in the way of precipitation over Arizona through 12 UTC on Friday (above). The operational GFS from last evening, however, forecast a fairly large area of precipitation accumulating over much of Arizona through the same period. So some chance of the first precipitation of the New Year later this week, but considerable uncertainty still in the cards.

Sunday, January 05, 2014

San Francisco Visits Green Bay Today

Photo above is looking toward the stadium in Green Bay this morning - looks quiet and a bit chilly. However, the 8 am CST surface observations (below) show temperatures across Wisconsin ranging from -26 F to +15 F, from northwest to southeast. Green Bay was reporting +5 F. Some snow from the storm to the south has spread as far north as the Chicago area. I'm sure it will be a memorable day for some of the San Francisco team members - regardless of the outcome. A good day to be watching the game from Tucson!

Saturday, January 04, 2014

Frigid Weekend For Eastern And Central U.S.

The NWS map of current watches and warnings (above) continues to be a colorful display this morning (Saturday, January 4th). Another storm is developing over the Plains, as a new push of arctic air heads south and eastward. So travel delays, and other widespread, winter weather problems will continue through the weekend for much of the country.

I took a look at the NWS GFS model's ensemble forecasts from 00 UTC last evening to get a feel for when the NH pattern at 500 mb might change. Above graphic shows the 500 mb height averages and departures from normal valid at 48-hours - dominant features are the strong, west coast ridge and the cold lows over the Great Lakes and north Atlantic. By 144-hours (below) the west coast ridge has flattened some, and shifted westward, as lower heights push briefly into the West. However, by 228-hours (bottom) the ridge has strengthened again, just off the west coast. This pattern persists through the entire forecast run (out through 384-hours) indicating that the extreme dryness over much of the West and Southwest will likely continue through much of January and that the East will have to endure a long, strong siege of winter weather.