Warmest Year On Record - 2014

Globally, 2014 was the warmest year ever within the period of observational records. There are a number of news stories available about this, but something that really caught my eye was the above photograph from the 2014 version of the famous Alaskan sled race.

More Urban Wildlife

Neighbor John Ferner captured these photos of a large raccoon coming and going through their courtyard last night.

Bit More On Yesterday's Winds

I checked back on the WRF forecasts for winds yesterday afternoon and found that they were very good for a number of runs before the event. So the WRF variants continue to have a good track record forecasting gusty winds from the east - winds that often are overlooked in some forecasts. Above graphic shows the 12 UTC forecast from the WRF-NAM of 10-m winds valid at 1:00 pm MST yesterday. A few selected observations of maximum gusts yesterday afternoon - NWS TUS 30 mph; Saguaro RAWS 33 mph; along Rillito Wash E35 mph; Pioneer Field 36 mph; and Mt. Hopkins RAWS 61 mph.

Mike Leuthold was driving east-bound on I-10 yesterday afternoon and took these photos of large dust plumes blowing off the Wilcox playa around 3:30 pm. Top two are a long-distance perspective of the blowing dust, while two photos below are view from north of the playa dust source.

Finally, I want to note that Mike is now running a 00 UTC version of the WRF models that includes a high-resolution (1.8 km grid) domain that extends eastward across most of New Mexico. Example below is current run's forecast of 10-m winds valid at 11:00 am MST this morning (Friday, January 16th). These are available online at his WRF url.

Strong Easterly Winds Across Parts Of Tucson Metro Area

Was occupied with other things this morning and did not notice the increasing pressure gradient across our region. Winds here along the Rillito Wash are gusting 30 to 35 mph currently (around 30 mph at the airport). The above graphic shows VAD winds derived from the TUS Doppler radar data this afternoon (heights are ft above the elevation of the radar), with 20 to 40 mph common. Surface plot below is from MesoWest at Univ. of Utah and is valid at at 2:50 pm MST. The wind gust speeds are indicated in red - so definitely a blustery afternoon 

Cold Rain Showers Here

Edited to add: Close but no cigar today. My guess that showers would develop just to east was off, and the showers developed from northwest to southeast across the west edges of the Tucson metro area at mid-day. We picked up 0.03" additional rainfall here, but the Rillito at Dodge ALERT gauge, just a bit less than a mile east of here, had 0.20". In fact, 60% of the ALERT sites had 0.04" or more precipitation from the showers this afternoon - so much more activity than I had anticipated. There were even several cloud to ground flashes and a thunderstorm up in Oro Valley around 2:00 to 2:30 pm MST.

Update - Showers got going from northwest to east of metro area early this afternoon.  All images here are from just before to a bit after 2 pm MST. Currently a shower here at house of very cold rain.

Unusual Foggy Morning In Tucson Metro

Light showers did move across parts of the metro area last evening - here at house we have 0.07" in gauge this morning (better than the "event" of Sunday night). Cool air moving in with and behind the showers has led to an unusual desert morning with thick fog across much of eastern Pima County. Photo above is looking north from Kitt Peak at the fog across the lower elevations. Photo below is from the house looking toward the Catalinas with the visibility about a 1/4 of a mile. Both photos were from a bit before 8 am MST.

The 500 mb analysis at 12 UTC this morning, Wednesday, January 14th (above from NCAR RAL), shows that the short wave has dug south-southwestward and is now centered over Arizona. Temperatures with this feature are -20 C or colder and the cold pool will move eastward today, just to our north. The morning sounding from TWC on campus (below, from the SPC) has a surprising bit of CAPE below 500 mb. There is an indication of drier air moving in aloft on the westerly winds. So the forecast issue for today is whether or not convective showers will develop before the dry air invades eastern Pima County. Some sunshine would also be needed. So this is a difficult forecast question for late morning to early afternoon. My assessment, based on a very quick look, is that showers that develop will probably be just off to the east.

Kind Of A Hit/Miss Event

The weather event of past 24-hours was somewhat both a hit and a miss. The images here (Kitt Peak looking north - above) and visible satellite image below (both from around 4 pm MST on Monday, January 12th) show that there are still considerable clouds around, but these have produced only some sprinkles since midday.

The nighttime rainfall across eastern Pima County was very light (mostly a few hundreths). The two metro sectors of the ALERT network (shown above and below) are from around 3 pm for past 24-hours. Most parts of these sectors had around 0.04" or less (amounts less than 0.04" show as zero). Here at the house we had 0.02" at sunrise and nothing since. However, showers at mid-morning moved across the southeastern third of the network and dropped rainfall of several tenths of an inch. Thus, the hit and miss character of the event. Another shortwave/closed low at 500 mb will flirt with us tomorrow and may produce some showers this far south; however, the main impact will be chilly northwest winds as the associated front comes through. Tonight a backdoor front will sneak into Cochise County, before being pushed away tomorrow by the system approaching from the northwest.

Quick Look At Next Weather Event

The next 500 mb short wave is moving across southern California at this time and will be impacting Arizona tonight and tomorrow morning. The surface plot above is from just before 3 pm MST (Sunday, January 11th) and indicates some rainfall occurring into northwestern Arizona.

The morning WRF forecasts from Atmo indicate widespread, light rainfall with this system - much as per the last event on Thursday the 8th. Forecast above is of composite radar echoes and is valid at 11 pm MST tonight. Forecast below is of total precipitation through noon tomorrow. Both forecasts are from the WRF-NAM initialized at 12 UTC this morning. So, weather conditions across eastern Pima County should deteriorate rapidly late this afternoon and evening as the short wave approaches.

Unsettled Conditions Continue For Next Several Days

Yesterday's showers turned out to be considerably more than were expected (POPs were 20% for the day as the sun came up) and ended up with more than 90% of the ALERT network sites measuring rainfall. Amounts maximized across the metro area from east-to-west, with much lighter amounts  to north and south. The two ALERT sectors with most rainfall are shown above and below - maximum amounts reached 0.35". Here at house we came in with 0.29".

The Southwest continues to be under the influence, at 500 mb, of a weak, southerly branch of the flow that undercuts the large ridge over western Canada and Alaska. There are a number of short waves and closed lows in this stream that will impact southern Arizona into next week. Graphic above is the ECMWF 500 mb forecast valid at 5 pm MST on Sunday afternoon and indicates another short wave about to cross southern California. The weak large-scale setting means that anticipating the day-to-day details of weather in the metro area will continue difficult. The current NWS grid point forecast for the airport is shown below and indicates low POPs, but for almost all forecast periods through next Tuesday. The WRF forecast from Atmo indicates the possibility of a few more sprinkles today over eastern Pima County as the closed, 500 mb low to our south moves eastward across northern Mexico.

East-West Bands Of Showers Across Metro Area

Bands of light to moderate showers have been crossing over the metro area from east to west for past few hours. This has produced rain amounts that are considerably more than what I was expecting this morning. So, our first dreary and soggy weather event of 2015 continue this late afternoon. Above is NWS TUS composite radar at about 3:15 pm MST and below is current rainfall over the west-metro sector of the Pima County ALERT network.

Showers Around This Morning

It is a mild morning in the Tucson area with cloud cover and easterly winds that blew through the night - even here at house. So it is the first morning here of 2015 that has not had lows in the 20s or colder - quite nice for a change.

This morning there are sprinkles and some heavier showers across much of southeastern Arizona. Graphic above is composite radar echoes at 6:30 am MST from NWS TUS. heavier showers are currently off to south and east of the metro area. Reflectivities are high in some showers but tops are fairly low, and there seem to have been no detected CG lightning flashes up to this time.

The 12 UTC morning sounding from TWC (the NWS Office on the Univ. of Arizona campus) is shown below. The value of PW has climbed to nearly an inch, even though atmosphere is relatively dry below 700 mb. So, showers are based above the mountain tops and precipitation will be more significant at higher elevations (looks like there has been 0.04" out at the NWS radar site in the Empire Mountains). The early WRF-NAM forecasts the high RH to remain mostly above 700 mb through the day. So an unsettled day on tap with some periods of showers across the region but little in the way of accumulations.

Quick Look Ahead

As the 500 mb cyclone near Baja moves northward, increased moisture is moving north on both sides of Baja. Above is visible satellite image from 2230 UTC this afternoon (January 6th). Below is 22 UTC blended PW from CIRA at Colorado State University - values of PW near and greater than an inch have progressed almost half way up the GoC. The models are quite variable with the forecast for the next several days and if we get some showers it is currently not very clear when they might materialize. So, we can definitely count on increasing clouds and virga and sprinkles but measurable rain chances and timing remain more ambiguous at this time.

What is most definite is that the westward push of the arctic high pressure from the Southern Plains will bring strong easterly winds to our area. Graphic below shows the WRF-GFS forecast of 10-m winds valid at noon tomorrow. The model keeps the winds strong through Wednesday night into Thursday. So low temperatures may jump all over the place, depending on where and when the winds blow - add in the cloud cover and temperature forecasts become a challenge also for next several days. Today was an example - temperature dropped briefly to 40 F at airport but was down to 27 F here at house.

December 2013 VS 2014 Over The West

Dan Lindsay (NOAA, CIRA at Colorado State University) posted these images to the MAP list yesterday. The maps show departures from the long-term December average precipitation - 2013 above and 2014 below. Note that this year's December was wetter than average to about same extent as 2013 was dry (~ 8 inches) over parts of northern California. The last few days have brought extremely heavy rains to portions of northwest Washington state, where drought prevailed during 2013. Similar flip-flops have occurred over portions of Arizona, but of much smaller magnitude, of course. The maps were generated at:                     http://water.weather.gov/ahps/

Weather Features Of Interest Midweek

First - easterly winds have been been surfacing this morning down at the airport after midnight, making the temperature jump up and down. The low at TUS was a bit after midnight and was 38 F. Winds remain calm here at the house and morning low was 23 F. So there was quite a temperature gradient between here and airport - especially around 6:00 am MST when the TUS temperature had jumped up to 52 F.

Currently there is a middle and upper-level cyclone centered southwest of the southern end of Baja - above is 12 UTC NAM analysis at 500 mb this morning (January 5th). This feature is forecast to move northward during the next 3 days, impacting southeastern Arizona as it moves toward the north end of the GoC.

Graphic below is from today's early WRF-NAM model (on the 5.4 km grid) at Atmo and shows PW valid at 5:00 am MST this morning. The PW is very low currently all the way down the GoC.

However, as the 500 mb cyclone moves northward, PW increases markedly all the way into southeastern Arizona. Forecast of PW from WRF-NAM above is valid at 11:00 pm on Wednesday night (January 7th). The model forecasts very light showers along the Borderlands at this time.

The situation will be further complicated by a strong, back-door cold front crossing the Continental Divide and pushing westward across southern Arizona. Strong downslope winds with this feature (below shows forecast of 10-m winds valid at 11:00 pm MST Wednesday night) will be interacting with the advancing moisture plume from low latitudes. Thus, a complicated weather scenario for us to watch here, while most of the country will be focused on the cold and extreme high pressure associated with the arctic air mass over the central U.S.

NWS 2014 Summary For TUS

Has been cold and frosty mornings so far for 2015 - lows here at house beginning on the 1st: 23, 21, 18, and 19 F this morning the fourth. More cactus damage last two mornings.

The link below will take you to  the observational summary of 2014 for the NWS observations at TUS (the airport) that has been compiled by John Glueck at the NWS office. It appears that 20014 was the warmest year ever recorded here at the "official" NWS observation site..

http://www.wrh.noaa.gov/twc/climate/monthly/2014.php

Image below from Kitt Peak about 2:30 pm MST, showing snow cover up there and with Boboquiveri in the distance.

Heavy Snows In Southeast Corner Of State

Mike Leuthold, emailing from Paradise, Arizona, reports periods of very heavy snows there yesterday (January 2nd). View is from his remote get-a-way, looking toward Silver Peak in the Chiricahuas.
Note that Paradise is located a bit northwest of Portal.

Snow Photos New Year's Day 2015

Wishing the best for 2015 to all who visit here.

We were at Santa Rita Abbey northwest of Sonoita on New Year's Eve and experienced a slight snowfall there. I see that NWS observations at the airport also indicated a bit of snow just before midnight.  The rain and then snow at the Abbey was much lighter than over here in Tucson area. The grid-point forecast for out there, as per just before we left around 4 pm on Wednesday, was POPs 60% Wednesday and 70% Wednesday night, with snow accumulations of 1-3 inches possible. There was no precipitation out there on Wednesday - we were kicking up dust on Gardner Canyon and Fish Creek Roads. But light rain began a bit after 6 pm MST and then quickly turned to light snow. There was about a quarter inch of high water-content snow on the grass at sunrise - very crispy and crunchy to the step.

On return to house I was surprised to find 0.51" of rain in the gauge - have no idea if there was a bit of snow mixed in here. This final weather event of 2014 brings December rainfall here to 2.41 inches, which is a tie for second wettest December since my measurements began back in 1999.

Below are several photos from morning of first day of 2015.

Mount Wrightson and the Santa Ritas looking west-southwest from Santa Rita Abbey.

Photo by Art Rangno looking east from near Catalina up to Mt. Lemmon.

Photo by Bill Cotton taken east of Catalina of snow-blasted saguaros.