Feeds:
Posts
Comments

Archive for the ‘GOES-R Proving Ground’ Category

November 19th has been eagerly anticipated by the meteorological community as it is the launch of the next-generation GOES-R satellite.  The satellite will carry a suite of space weather instruments as well as two Earth observing sensors.  The Advanced Baseline Imager (ABI) will provide three times more channels to view the Earth, four times greater spatial resolution, and 5 times faster coverage.  The ABI will provide new means to monitor atmospheric phenomena.  Additionally, GOES-R will carry the first ever lightning observation sensor on a geostationary platform; the Geostationary Lightning Mapper (GLM).  Numerous organizations, including NASA SPoRT, have been supporting the GOES-R Proving Ground for many years to aid the operational community in preparing for the new capabilities of GOES-R.

Specifically, NASA SPoRT has been formally involved with the Proving Ground since 2009, although much of our work prior to this point has provided relevant information with respect to GOES-R.  SPoRT has been primarily involved in two activities.  The first has been the assessment of and training for multi-spectral imagery, often called red-green-blue (RGB) composites.  The RGB composites are used to combine multiple single channels into a single image in order to help emphasize phenomena that forecasters wish to monitor.  This can range from air mass microphysics to atmospheric dust.  This work has leveraged work by Europe’s EUMETSAT organization who first developed several of these RGB composites for their Meteosat Second Generation satellite.  SPoRT has worked with NASA’s MODIS instruments from Aqua and Terra as well as the JPSS VIIRS instrument to create the respective RGBs from polar orbiting instruments.  These snapshot demonstrations provided forecasters local examples of RGB composites to allow them to investigate these products prior to GOES-R’s launch.  SPoRT has also coordinated with other product developers to help transition their early development work to National Weather Service forecasters.  This included the University of Alabama in Huntsville’s GOES-R convective initiation product and the NESDIS quantitative precipitation product.

image2

MODIS Dust RGB demonstrating a future capability of the GOES-R ABI. Dust (magenta) can be seen approaching Las Vegas, Nevada.

In additional to the ABI work, SPoRT has been integral to supporting total lightning (intra-cloud and cloud-to-ground) observations in operational applications.  This dates back to 2003 with the first transition of experimental ground-based lightning mapping arrays that evolved into the pseudo-geostationary lightning mapper (PGLM) product in 2009 to provide operational training for the GLM.  Since then, SPoRT has developed the GLM plug-in for the National Weather Service’s AWIPS system, has personnel serving as the National Weather Service liaison for the GLM, and have developed foundational training that is being provided to every forecaster in the National Weather Service.

tornado_alt_25apr10-11

Sample of the pseudo-geostationary lightning mapper demonstration product in AWIPS being used for training on the Geostationary Lightning Mapper.

SPoRT will continue to be actively engaged in GOES-R applications post launch.  This will take the form of developing an applications library, or short 3-5 focused case examples, for both the ABI RGBs and the GLM.  SPoRT will also participate in the formal applications training for RGBs and GLM that will be released to the National Weather Service.  Lastly, SPoRT will be leading an operational assessment of the GLM with National Weather Service forecasters and associated emergency managers.

goes_r_launch_19nov16

GOES-R launching on November 19, 2016!

Read Full Post »

Here at the Huntsville, AL Weather Forecast Office (WFO) we’ve pointed out total lightning data’s operational utility a number of times in this blog.  After all, the data have been a rather integral part of our severe weather operations for at least 13 years.  Anyway…I’m going to do it again.  I think it can be beneficial to reiterate the value of certain data sets from time to time, especially to reemphasize their operational utility to new members of the forecasting and research community and perhaps newcomers to the SPoRT blog.

This afternoon and evening was a somewhat typical summertime convective event for the Tennessee Valley.  Showers and thunderstorms developed in the early afternoon and gradually increased in coverage and intensity during the mid to late afternoon hours.  By the time I arrived on shift at about 3 pm CDT, a few thunderstorms were showing signs of intense updrafts (~50 dBZ at the -10C isotherm level), but were still not to the level of producing severe weather.  Nevertheless, multiple outflow boundaries interacting with the hot, humid and unstable airmass caused decent coverage of shower and thunderstorm activity, especially in northeastern portions of Alabama during the mid afternoon into the early evening.  A few thunderstorms contained strong updrafts, heavy rainfall, frequent lightning and wind gusts up to about 40 mph.  The first of these started showing signs of strengthening in eastern portions of DeKalb County, AL shortly after 3 pm CDT.  The first image below (image 1) shows a snapshot of total lightning data (flash extent density) from the North Alabama Lightning Mapping Array (NALMA) at 2014 UTC.  Values at this time in the developing storm were just around 10 flashes per 2-minutes.  By 2022 UTC however, flashes had increased to nearly 50 flashes per 2-minutes (Image 2).

Total Lightning (per North Alabama Lightning Mapping Array), 23 July 2016 2014 UTC

Image 1. Total Lightning (per North Alabama Lightning Mapping Array), 23 July 2016 2014 UTC

Image 2.

Image 2.  Total lightning (per NALMA), 23 July 2016 2022 UTC

Importantly, increases in total lightning activity are directly related to updraft strength within storm cells so it was no surprise that reflectivity values increased correspondingly.  The next two images show the increases in Multi-radar Multi-sensor (MRMS) isothermal reflectivity (dBZ) at the -20 C level during the same period (Images 3 and 4).

Image 3. Multi-radar Multi-sensor isothermal reflectivity (dBZ) 23 July 2016 2014 UTC

Image 3. Multi-radar Multi-sensor isothermal reflectivity (dBZ) at -20 C over portions of NW Alabama and NW Georgia, 23 July 2016 2014 UTC

 

Image 4.

Image 4.  Multi-radar Multi-sensor isothermal reflectivity (dBZ) at -20 C over portions of NE Alabama and NW Georgia, 23 July 2016 2022 UTC

Data such as the MRMS isothermal reflectivity when used in conjunction with other data such as total lightning (or flash extent density) allow for a good evaluation of updraft development within thunderstorms and their evolution through time.  Environmental parameters on this day suggested that severe weather was not likely.  Nevertheless, the strengthening updrafts were followed by wind gusts around 30 to 40 mph, which were recorded at a few of our surface observation sites.  Special Weather Statements were used to address this marginal thunderstorm threat during the afternoon and evening.  Interestingly, notice that the total lightning data at 2022 UTC (Image 2) indicated that the updraft in the northern cell in DeKalb County was perhaps the strongest at the time (due to higher values on flash extent density), while MRMS reflectivity values were higher at the same time in the southern cell (image 4).  Subsequently, the northern cell strengthened and became the dominant cell over the next 30 minutes.  On days such as this when there are often multiple thunderstorms ongoing at any one time, and this happens often here in the TN Valley in the summertime, total lightning data can be an effective situational awareness tool for evaluating storms that are undergoing strengthening and helping to provide proper focus for operational meteorologists.

Read Full Post »

NWS Huntsville is providing Impact-Based Decision Support Services (IDSS) to protect life and property at an outdoor sporting competition in the Decatur, Alabama area this week.  A decaying Mesoscale Convective System (MCS) moved across north Alabama this afternoon, forcing a delay in the competition for several hours.  While the North Alabama Lightning Mapping Array (NALMA) helped determine what to tell local emergency managers about the start of the lightning threat, the NALMA really shined in trying to figure out when the lightning threat would end.

KGWX Radar Reflectivity and North Alabama Lightning Mapping Array, valid 1949 UTC 14 July 2016

KGWX Radar Reflectivity and North Alabama Lightning Mapping Array, valid 1949 UTC 14 July 2016

The example images include NALMA Flash Extent Density data, which are represented by irregular pink and purple shapes displayed over the KGWX radar reflectivity.  Both the 1949 and 2007 UTC indicate scattered very low flash rates extending over a broad area–including the Decatur area–suggesting occasional in-cloud flashes within the trailing stratiform region of the MCS.  This is a known threat with MCSs, but it was not clear at the time how long the lightning threat would persist.  Use of total lightning information from NALMA enabled NWS Huntsville staff to determine that the lightning threat would not subside until rain subsided.

KGWX Radar Reflectivity and North Alabama Lightning Mapping Array, valid 2007 UTC 14 July 2016

KGWX Radar Reflectivity and North Alabama Lightning Mapping Array, valid 2007 UTC 14 July 2016

With the launch of GOES-R and the Geostationary Lightning Mapper, these kinds of data will improve lightning-based IDSS across a much wider cross section of the CONUS.

Read Full Post »

A potent winter storm system impacted portions of New Mexico on March 26, 2016, ending an extended stretch of very dry weather. Snowfall amounts of 3 to 9 inches were reported from the Sangre de Cristo Mountains eastward across the northeast plains. The MODIS and VIIRS satellite products proved useful for illustrating the extent of snow cover in both the daytime and nighttime scenes. The images below are graphical briefings posted to the NWS Albuquerque web page and shared via Twitter after this much needed snowfall event.

Graphical briefing showing the extent of snow cover during the nighttime and daytime periods on March 27, 2016.

Graphical briefing (part one) showing the extent of snow cover during the nighttime and daytime periods on March 27, 2016.

Graphical briefing showing the extent of snow cover through RGBs on March 27, 2016.

Graphical briefing (part two) showing the extent of snow cover through RGBs on March 27, 2016.

Read Full Post »

MODIS Air Mass RGB (left) and 11 um image (right) from 08 February 2016 at 1427 UTC.

MODIS Air Mass RGB (left) and 11 um image (right) from 08 February 2016 at 1427 UTC.

An image captured this morning by the MODIS Terra instrument shows an impressive cyclone off the eastern coast of the US. The image on the left shows the cyclone in SPoRT’s Air Mass RGB and the image on the right shows the 11.0 µm from Terra (from 8 February 2016 at 1427 UTC). The deep red color on the RGB shows the intrusion of ozone-rich stratospheric air, which is an indication of deformation zones, jet streaks, and potential vorticity anomalies associated with rapid cyclogenesis, which itself indicates strong winds at the surface. This RGB is also limb-corrected for cooling at the edges of the swath, so we can assume the cyclone in this imagery is every bit as intense as it looks.

The new generation of geostationary satellites being deployed globally, such as Himawari, MTG, and GOES-R, will allow us to observe imagery like the Air Mass RGB several times an hour, enabling us to watch the cyclogenesis as it happens.

Read Full Post »

So, here at NWS HUN, I’ve recently begun ingesting and looking at the GOES-R Fog and Low Stratus (GOES-R FLS) Product.  True, while this is not a SPoRT product, it is a part of the GOES-R Proving Ground and is certainly worthy of operational evaluation and comparison with other GOES-R and JPSS Proving Ground products provided by SPoRT and other entities.  So, this morning, I noticed a relatively extensive patch of what appeared to be mid and high clouds streaming across southern Texas in advance of a weak, sheared trough in the SW CONUS and NW Mexico (Image 1).

GOES visible imagery at 1900 UTC 13 Nov 2015. Observations also shown. The numbers at the bottom of the ob indicate the visibility in statute miles, while the numbers to the left indicate cloud layer heights in hundreds of feet AGL. For example, 90 = 9000 ft AGL.

Image 1.  GOES visible imagery at 1900 UTC 13 Nov 2015. Observations also shown. The numbers at the bottom of the ob indicate the visibility in statute miles, while the numbers to the left indicate cloud layer heights in hundreds of feet AGL. For example, 90 = 9000 ft AGL.

Observations show that most cloud bases in the region were above ~6500 ft AGL.  A look at the GOES-R FLS MVFR Probability product also indicated low chances for MVFR conditions within the cloud shield across the region…with the exception of portions of far southern Texas (Image 2).

Image 2. GOES-R FLS MVFR Probability product at 1900 UTC 13 Nov 2015. Note that based on the color scale (top left) black colors cover much of this area of clouds in southern/eastern TX, with the exception of a small area in far Southern TX near Brownsville and adjacent areas to the south and east.

Image 2. GOES-R FLS MVFR Probability product at 1900 UTC 13 Nov 2015. Note that based on the color scale (top left) black colors cover much of this area of clouds in southern/eastern TX, with the exception of a small area in far Southern TX near Brownsville and adjacent areas to the south and east.

So, how is this value added to the operational weather forecaster?  Easy…it offers a more efficient look at clouds that are impactful…especially to aviation forecast concerns.  The FLS MVFR Probability product in this situation would have shown a forecaster in rather quick fashion that the developing band of clouds upstream from his/her area were generally VFR.  Sure, an interrogation of ground observations would have suggested the same thing, but only at point locations of course.  Forecasters are usually wanting to know what’s going on in between ground observation sites.  Homogeneity may be safely assumed in some cases, but it’s always good to have other sources of information that may verify these assumptions or reduce risk in assumptions.

I have some other thoughts about these data/imagery and will be taking more looks at these data and comparing with other legacy and GOES-R/JPSS Proving Ground products in the future…especially when I have the opportunity to use them operationally in my own area.

Read Full Post »

Over the last few days Himawari-8 AHI Air Mass RGB imagery has captured an impressive view of Severe Tropical Storm Choi-wan near Japan.  The storm began as a tropical depression near Wake Island and the Japan Meteorological Agency upgraded the depression to a tropical storm on October 2nd.  The tropical storm continued to move north-northwest toward Japan and the Sea of Okhotsh but weakened as it evolved.  Yesterday and today (October 8th) the storm began to take on more extratropical characteristics and look like a strong mid-latitude low pressure system (click on Fig. 1 animation).

Himawari-8 AHI Air Mass RGB 0000 UTC 6 October 2015 to2020 UTC 8 October 2015

Figure 1. Himawari-8 AHI Air Mass RGB 0000 UTC 6 October 2015 to2020 UTC 8 October 2015

Currently, SPoRT is investigating the utility of NOAA Unique CrIS/ATMS Processing System (NUCAPS) satellite retrieved soundings for hurricane tropical to extratropical transition events. Soundings are typically used to anticipate severe weather and analyze the pre-convective environment; however, they can be just as valuable for analyzing and understanding the environment surrounding complex extratropical transition events, especially over data sparse oceanic regions. National Center forecasters at the National Hurricane Center and Ocean Prediction Center routinely use the Air Mass RGB for forecasting such events, especially for identifying the influence of warm, dry stratospheric air during extratropical transition.  Although the Air Mass RGB provides a wealth of information about the upper-level horizontal distribution of temperature and moisture characteristics surrounding a storm, it does not provide insight about the vertical distribution of thermodynamic characteristics. With Next-Generation S-NPP/JPSS NUCAPS Soundings now available in AWIPS-II, they can be used in conjunction with the Air Mass RGB to anticipate extratropical transition events.

Here are a few examples of NUCAPS Soundings compared to the Air Mass RGB. Let’s take a look at NUCAPS Soundings in three locations in the environment surrounding Severe Tropical Storm Choi-wan (Fig. 2).

Himawari-8 AHI Air Mass RGB 1520 UTC 7 October 2015 capturing an impressive

Figure 2. Himawari-8 AHI Air Mass RGB 15:20 UTC 7 October 2015 capturing impressive view of Severe Tropical Storm Choi-wan near Japan and NUCAPS Sounding point locations (green dots) 1500 UTC

Location 1, red/orange coloring, represents upper-level dry air on the Air Mass RGB.  To no surprise, the NUCAPS Sounding (Fig. 3) reveals dry upper-levels and dry conditions throughout the atmospheric column.

NUCAPS Sounding 1500 UTC 7 October 2015 taken near label 1 in the Air Mass RGB in a region representative of upper-level dry air (orange coloring)

Figure 2. NUCAPS Sounding 1500 UTC 7 October 2015 taken near Location 1 in the Air Mass RGB(Fig. 2) in a region representative of upper-level dry air (red/orange color)

Now Location 2 is also in an orange colored region and representative of upper-level dry air, but take note the coloring is not as “red tinted” as Location 1 and there are more mid-level clouds.  Mid-level clouds tend to be light tan or ocher colored in the Air Mass RGB.  The NUCAPS Sounding (Fig. 3) does confirm a mid-level moisture layer from about 800-600 mb. Seeing ocher clouds in the RGB only means that qualitatively mid-level clouds are present (one can’t get a quantitative height from the RGB), but inspection of the NUCAPS Sounding would give a quantitative height estimate of the mid-level clouds.  Although this sounding is in the region right over the mid-level cloud, looking at more soundings in the same orange region (but not right over a cloud) do show the atmospheric column is not completely dry (like Location 1) but there is low- to mid-level moisture present throughout the region surrounding Location 2.  Just by looking at the RGB one may not realize a mid- to low-level moisture layer is present since the interpretation of the orange coloring in the Air Mass RGB is upper-level dry air.

NUCAPS Sounding

Figure 3. NUCAPS Sounding 1500 UTC 7 October 2015 taken near Location 2 in the Air Mass RGB (Fig. 2) in a region representative of upper-level dry air (orange coloring) and mid-level clouds (light orange or ocher color)

Location 3 is the most interesting (at least to me since the sounding gives more information about the atmosphere than one could extrapolate from just looking at the Air Mass RGB).  The green coloring around Location 3 represents a warm, moist air mass.  The NUCAPS Sounding (Fig. 4) does reveal a more moist sounding about 300 mb and above, but note there is mid-level dry air present and a low level moist layer.  Again the NUCAPS Soundings provide more information about mid- and low- level characteristics that one can’t infer from the RGB imagery.  This is just one example that highlights the utility of analyzing Next-Generation satellite data sets for complex weather events in data sparse regions.

NUCAPS Sounding

Figure 4. NUCAPS Sounding 1500 UTC 7 October 2015 taken near Location 3 in the Air Mass RGB (Fig. 2) in a region representative of upper-level moist air (orange coloring) and mid-level clouds (green color)

Read Full Post »

Older Posts »