Tuesday, November 30, 2010

Nov. 30 - LOW WIND HIGH PM EVENT (possible) - At 6 pm the border sites are tending toward a low wind, high particulate event especially at the Sunland Park site. More to come.

Monday, November 29, 2010

Nov. 29 - HIGH WIND DUST EVENT - It was a windy midday. Although not as intense as the last high wind event peak PM10 levels reached 300 ug/m3 at the Sunland Park City Yard site at 3 pm. Winds peak around 10 m/s at that time.
In comparison the NMED Deming site PM10 peaked at 150 ug/m3 at 3 pm. At 3:16 pm the LC airport AWOS recorded a wind speed of 28 mph and a gust of 35 mph. At 8 pm the EPA AQI posted this map showing an area of moderate air quality (yellow) in central Dona Ana County.

Sunday, November 28, 2010

Nov. 28 - HIGH WIND DUST EVENT - We're seeing windblown dust just as forecasted in the border area. The 3 pm visible GOES Satellite image showed extensive dust plumes from both Mexico and New Mexico. Winds at the LC airport were from the SW at 35 mph gusting to 46 mph at 12:56 pm MST.

Surface weather map shows the event with visibilities
The 1 pm PM10 concentration at the Sunland Park City Yard was 2953 ug/m3 and PM2.5 was 180 ug/m3 with hourly averaged winds of 11 m/s and 19 m/s gusts. The air quality is in the Hazardous category (AQI > 500).

The plot below shows the particulates at the NMED Anthony Elementary monitoring site.
A view from my office window looking out toward the west shows this dust in Las Cruces
TCEQ has provided a nice summary of the Nov. 28 dust event based on their monitoring data and an animation of GOES images.

Nov. 27 - LOW WIND EVENT - The cold remains in our area today. Low temperature at the LC airport was  a frigid 18 degrees at 7:15 am. The low at the NMSU NWS station was 19 degrees. High clouds covered the area most of the day based on both MODIS pass images. Below is the afternoon MODIS true-color image taken from the Aqua satellite.

Where I am in Green Valley Henderson it dipped to 26. Nellis AFB was a little cooler at 22. At the strip the temperature cooled to only 34 and 30 at the DRI campus. Warm temperatures probably due to some urban heat island going on. In the region, Furnace Creek Death Valley cooled to 29 degrees. That's pretty amazing given its location and elevation.

Tonight we saw another low wind, high PM10/PM2.5 event at the border. The Sunland Park City Yard site had some impressive concentrations. At 9 pm, hourly PM10 was 397 ug/m3 and PM2.5 was 108 ug/m3 with a wind speed of 1 m/s as the plot below shows.

Back in southern New Mexico high west southwest winds are forecasted for Sunday during the day in the 30 to 33 mph range with gusts up to 47 mph. That should be enough to get dust off the ground especially in the dust prone areas. I'm still out of town so this event will have to be covered with data I can get on the net. Our area is also under a red flag and wind advisory.
I pulled this forecast graphic from the Santa Teresa NWS website late Saturday night and it shows the extent of the high winds.Looking at Monday we see more winds but not as strong.

Saturday, November 27, 2010

Nov. 26 - (LOW WIND EVENT) Another cold day. LC airport lows were around 25 and will probably be lower Saturday morning. I don't have the low at the campus station but will post it as soon as I get it. (update: low of 20F) Clear skies prevailed today as viewed from the MODIS afternoon pass. Snowfall in northern NM is clear in the image with some snow across the Cibola National Forest, southern Navajo Reservation, and higher elevations around the Gallup/Grants area.

Another evening low wind, high particulate matter event in Sunland Park and surroudings. The event peaked at 6pm with hourly PM10 at 512 and PM2.5 at 162 ug/m3 as shown in the plot below. Winds were in the 1 m/s range at the time.

Based on the preliminary data from the website this is probably not a NAAQS exceedance but is a significant high particulate matter event. Anthony also is showing the same pattern at about the same time but at lower concentrations. The EPA current PM2.5 status shows this in the map.
The EPA map highlights the whole southcentral area with moderate AQI.  The forecast for Saturday is better with green conditions
The NWS forecast for Sunday is still calling for winds in the 26 to 29 mph range with gusts up to 40 mph in the border area.

Friday, November 26, 2010

Nov. 25 - I missed the past couple of days due to being on the road and finally have internet access. I'm in Southern Nevada where it's been very brisk on Thanksgiving. The low here in Henderson was a chilly 28 and ranged from 21 to 34 in the Las Vegas Valley. Still a freeze warning in for the LV Valley for Black Friday. Similar story for southern NM where there are "hard" freeze warnings going out from the NWS office. Forecast low for Las Cruces is 23 for Friday with light northernly winds. With that kind of temperatures I would not be surprised to see some decent temperature inversions causing high particulate matter concentrations in the morning hours as the boundary layer falls to very shallow depths as long as the winds are light. Nothing interesting in the MODIS AOD product on Thursday as levels looked to be less than 0.2 which is low.

The Sunland Park City Yard NMED monitoring site recorded some high PM2.5 Thursday. At 2 pm peak PM2.5 ranged around 60 ug/m3 but PM10 was about 22 ug/m3. Maybe a instrument or calibration issue for that since we require that the PM2.5 mass be less than PM10 mass.

The EPA Air Quality Index (AQI) for the area shows some :moderate levels in southern NM.
The forecast shows a system coming in Sunday that might cause high winds and blowing dust. Will have to get an update on this on Friday.


Sunday, November 21, 2010

Nov. 21 - HIGH WIND DUST EVENT - As of 3 pm a wind blown dust event is happening in southern NM. We see high PM at the Anthony, Sunland Park, Chaparral, and Deming NMED monitoring sites. Winds across the region are high as seen in the 2:33 pm MST surface map.
The NWS issued a wind advisory for the Sacramento Mountains today. Recall that winds need to be at least 35 mph to have an advisory issued. Lowland winds are projected to be in the 20 to 30 mph range with gusts as high as 37 mph.

As of 10 pm, much of the wind has decreased except for a few places.The sites in southern Dona Ana county had the largest wind blown dust today. PM10 concentrations were highest at Sunland Park City Yard and Anthony. Peak hourly PM10 at the City Yard reached 615 µg/m3 today.

Sunland Park City Yard and Santa Teresa had the highest peak PM2.5. The PM2.5 at Anthony was higher throughout the day than the other sites. Peak PM2.5 at the City Yard reached 32 µg/m3 this afternoon.
Based on the raw hourly data from the NMED website there wasn't an exceedance of the NAAQS.
Nov 20 - It warmed up nicely today with high of 70 at the LC Airport, 69 in Santa Teresa, and 73 at the Deming Airport. High clouds most of the day probably kept the temperatures from even higher. It was breezy but based on my vantage point in LC it didn't produce much dust and visibility was normal.

MODIS aerosol optical depth was similar to yesterday with all values in the 0.1 to 0.2 range with the highest along the Rio Grande.
A low wind, high PM event is shaping up in Sunland Park this evening. Below is the hourly PM2.5 at the Sunland Park City Yard.

Tomorrow is expected to be windy with gusts in the 30 mph range from the west-southwest. That might be enough to blow dust in some areas. We'll wait and see.

Friday, November 19, 2010

Nov. 19 - Another nice fall day here in southern NM. High at the LC airport was 64 and 65 in Deming. Clear early in the day but high clouds drifted in the afternoon. Afternoon MODIS just confirms that.

Afternoon MODIS AOD inched up a little compared to yesterday, but just along the Rio Grande.

Looks like the same prescribed fires continued today and were active based on the HMS smoke and fire detection product below.

The Deming profiler showed the WSW winds near the surface and W winds aloft as I expected. Winds picked up in the afternoon, first aloft and then coupled down to the surface by around 02 UTC. I think this looks to be the signature of the shortwave trough that was supposed to be travelling across the region.

The 00 UTC sounding at Santa Teresa was very dry but I bet that's not the case going into 05 UTC after the switch over to some mid and high level clouds tonight.

Based on the PM10 and PM2.5 observations in LC and Deming this afternoon there were no wind erosion events. However it looks to be a low wind, high PM event along the border particularly at the Sunland Park City Yard site. PM10 peak at around 400 µg/m3, PM2.5 at 50 µg/m3, and winds less than or equal to 1 m/s at 6 pm. See the City Yard hourly PM2.5 plot below.

It looks like Anthony is following in the footsteps of the Sunland Park site with these low wind events although it's less extreme further north in Anthony.

The forecast for the weekend looks to be breezy with gusts up to 25 mph on Saturday and 32 mph on Sunday. The NWS forecast also points to a little cooling down after our nice warm spell this week.

Areas along the border are dry, with very little precipitation over the last two months. This map shows the percent of normal precipitation over the past 60-days. Any red color in the map is less than 25 percent of normal or more. I think some of those red areas also coincide with historical wind blown dust emitters.

Thursday, November 18, 2010

Nov. 18 - Continued to be a nice sunny day with some modest warming from yesterday. High at LC airport was 64 and low 27. Today's Aqua image showed very little cloud cover but missing western part of state.

I spent the whole day driving to and from Tucumcari so what I know is from data. While driving to Tucumcari I saw whisps of an elevated smoke plume that I thought looked like it was from the Gila prescribed fire. At around 10am I was at Carrizozo and noticed that the visibility decreased just below the height of the nearby mountain to the east, making the mixing height around 2900
feet AGL. However today's HMS smoke plume product does not show any plume over this area.

Below are the spot weather forecasts for the Albuquerque Weather Forecast Office (WFO). There was a request today for a 40 acre fire 8 miles south of San Antonio along the bosque. Also a 500 acre burn southeast of Datil.

Even at Tucumcari there was a hint of an aerosol layer looking toward the west. MODIS aerosol optical depth was again very low. The AOD from Aqua is shown below.

This evening's PM2.5 is looking high based on a graph from NMED's website. Peak PM2.5 was around 50 µg/m3 at 9 pm. Probably a low wind, high PM event.

and similar for Sunland Park at the City Yard site except a little earlier in the evening. Peak PM2.5 was around 45 µg/m3 at 6pm.

Wednesday, November 17, 2010

Nov. 17 - Nice sunny day in southern NM. High at the LC airport was 64F and low was 37F. So we're on a warming trend for the next few days. A few high clouds in the area in the morning but not visible in the MODIS afternoon image.

Air quality was in the good range for aerosols and ozone. The prescribed burn in the Gila looks to be continuing but the smoke plume looks to be staying close to the fire and since the winds are not as high as yesterday, it makes sense. MODIS aerosol optical depth looks very good but lots of missing values over our area.

I decided to take a look at modeled ozone concentrations at this late hour and the EPA guidance shows around 50 ppb for 8-hour concentrations across the region. The map is for 11 pm EST so that's 9 pm MST. The model is over predicting ozone compared to NMED's measurements. The 9 pm 8-hour average ozone at La Union was 29 ppb and 18 ppb at the Deming Airport.

Tuesday, November 16, 2010

Nov. 16 - Breezy today but not as active as yesterday. Overall a nice day as seen in this afternoon MODIS image.

Winds were more westerly today. It will be warming up over the next few days as we transition out of the trof to an upper level ridge. We'll probably see more calm conditions till Friday when another system comes through.

In terms of air quality this morning was calm with light winds and I saw some indication of a fair temperature inversion in the Mesilla valley. This morning's sounding at Santa Teresa showed this shallow inversion clearly with a very dry atmosphere above 700 mb.

The MODIS aerosol optical thickness was very low today across the region with the levels in the 0.1 range.

Smoke can be seen from a prescribed fire in the Gila today. The Mill/Scott RX was projected to burn up to 450 acres. Northwest flow transported some of the smoke towards the southeast.

Monday, November 15, 2010

Nov. 15 - Time to wake up this blog after a busy summer getting the project started. Nice start to a fall windy season with some brief high PM10 around the border region. In Las Cruces we had high PM10 on evening of Friday Nov 12, Saturday afternoon, and again today. Winds were not high on the 12 and 13th so not sure about the cause. Today was a mix of clouds, sun, winds, brief showers, sun, and repeat. The day started off partly cloudy with NMSU campus temperatures at the freezing mark. Northwest winds dominated the day and started off breezy after 10 am. Noticed a lot of virga and low clouds right around noon and helped bring in winds on top of the upper level short wave. No thunderstorms in Las Cruces but brief showers felt like the summer. Intense downdrafts did a number around noon to 1 pm with lots of blowing dust at the NMSU campus. The picture below was taken right during the episode at 12:59 pm.

Clouds covered the area so satellites will not be useful for this event as the afternoon MODIS Aqua image below shows.

Nothing real exciting on the EPZ radar except spotty rain going NW to SE. Core site at the NMSU farm saw the event but not that spectacular.
PM2.5 tape ran out yesterday evening and forgot to load a new one in time for this event. Made a note to myself to check often. Started up PM2.5 BAM around 2pm. The morning PM10 concentrations shows a little more particulate matter than I expected. The graph below shows data from the MetOne particle sizer located on the NMSU campus. The red line is the coarse 10 µm particle counts (counts per cubic meter) and the blue is the 0.5 µm counts. Peak counts for both particle sizes occurred at 1 pm corresponding to the high wind and blowing dust event. In the morning from 7 to 9 am before the high wind event the smaller particles are seen at higher numbers than after 10 am. I would expect that we see aerosols during this calm period to be mainly locally generated particles from traffic, road dust, home heating, and maybe some burning. My guess is that after 10 am wind blown dust was the dominant type particle. Based on this plot we can see the clear differences between wind blown dust and the urban particles.

The NMED Deming airport site also showed a high wind event in the morning and into mid-day. Graph below is from the NMED AQB website.

Based on the radar wind profiler south of Deming winds were high all morning deep in the atmosphere with 30 kt NW winds beginning in 08 UTC near the surface.

Got a call from a colleague about very high dust at Chaparral High School today. Based on what I heard they had dust coming into the school and some thought it was smoke. Here's the time series from the NMED AQB site at the Elementary School.

The blue line is the hourly PM10 and showed a peak at over 750 ug/m3 at 1 pm. Winds were from the northwest (red line) as in the rest of the area.