Lightning Jump in the North Alabama Lightning Mapping Array

It’s a busy day in North Alabama with NASA and NOAA aircraft in the region supporting a field campaign for GOES-16.  Another instrument supporting activities is the North Alabama Lightning Mapping Array (NALMA), which observes total lightning (both intra-cloud and cloud-to-ground).  SPoRT has been providing NALMA data to local forecast offices for 14 years and has used these data to serve as a proxy for the Geostationary Lightning Mapper on GOES-16 as part of the GOES-R Proving Ground.  The images below show the total lightning activity across southern Tennessee and northern Alabama at 2138 and 2152 UTC on 22 April 2017.  The main storm of interest is right along the Alabama-Tennessee border, just north of Huntsville, Alabama.  The maximum number of flashes per 2 square kilometers in two minutes is about 50 flashes at 2138.  In 14 minutes, that has jumped to nearly 150 flashes over two minutes highlighting a lightning jump.   A long flash extending to the south towards Huntsville is also seen.  This storm already had a severe thunderstorm warning active and the jump here indicates that the storm will maintain it’s intensity.  The weather community will look forward to the Geostationary Lightning Mapper observations when they a made available in the next few months.

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Total lightning observations from the North Alabama Lightning Mapping Array at 2138 UTC on 22 April 2017.

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Total lightning observations from the North Alabama Lightning Mapping Array at 2152 UTC on 22 April 2017.

Dust RGB analyzes “dryline” for 3/23/17

Dust RGB analyzes “dryline” for 3/23/17

 

The Dust RGB, originally from EUMETSAT and a capability of GOES-R/ABI, can be helpful in identifying features other than dust, including drylines. A dryline represents a sharp boundary at the surface between a dry air mass and moist air mass where there is a sudden change in dew point temperatures. In this event from 3/23/17, a dryline in eastern New Mexico and west Texas is distinguishable via the Dust RGB imagery animation from GOES-16 (Fig. 1), while a large dust plume (magenta) is impacting areas further west. Note that the visible imagery (Fig. 2) shows clouds forming along the dryline, but these clouds drift downwind toward the northeast as they mature, away from the dryline itself, making it difficult to monitor the dryline position.  However, the dryline position can easily be seen via the color difference of the Dust RGB across the boundary of dry and moist air, and in fact, the dryline appears fairly stationary or moves in a slight westward direction, opposite of the cloud motion.  In situ observations (Fig. 3) are a primary tool for monitoring the dryline location, but the advantage of satellite imagery is an increased spatial and temporal resolution for forecasters.

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Figure 1. GOES-16 Dust RGB valid from 2022 to 2322 UTC, on 23 March 2017 centered on extreme western Texas.  Dryline seen in color difference of cloud-free area in eastern New Mexico and west Texas while dust plume is in magenta shades.

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Figure 2. GOES-16 Visible (0.64u) channel valid from 2027 to 2322 UTC on 23 March 2017 as in Figure 1.

For the above and subsequent images/animations: NOAA’s GOES-16 satellite has not been declared operational and its data are preliminary and undergoing testing. Users receiving these data through any dissemination means  (including, but not limited to, PDA and GRB) assume all risk related to their use of GOES-16 data and NOAA disclaims any and all warranties, whether express or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose.

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Figure 3. METAR station plot of surface observations at 2143 UTC on 23 March 2017 centered over New Mexico.

The ability to identify drylines using the Dust RGB gives the forecaster the capability to analyze these boundaries in ways not seen before. In the Dust RGB (Fig. 4), the surface area on the dry side is seen as a purple color (i.e. increased red contribution), and the moist side appears more blue (i.e. less red). This dryline can be noted more easily than in visible imagery (Fig. 5) due to the sensitivity of the 12.3 micron channel used in the 12.3 – 10.35 micron difference within the Dust RGB red component.  The 12.3 micron channel goes from warmer to cooler brightness temperatures with changes in density from very dry to very moist air. The blue contribution is consistent on each side of the line because the surface temperature, and hence the 10.35 micron channel, does not change much from either side of the dryline. There is limited ability to identify drylines using high resolution visible imagery, as seen in the Midland WFO Graphicast (Fig. 6) where cumulus clouds are documented forming along the dryline. Unfortunately, visible imagery is only useable during daylight hours and a user is dependent on cloud features along the dryline in order to analyze its position. However, aside from the obvious value of the color difference in cloud free areas to depict the dryline, the Dust RGB, is viable both during daytime and nighttime hours.

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NtMicro RGB: Fog vs Stratus

NtMicro RGB: Fog vs Stratus

A veritable buffet of things to digest are occurring in this Nighttime Microphysics RGB animation from 0600 to 1000 UTC in the early morning of 3/28/17 where multi-state impacts of stratus and fog are seen (Fig 1). In blue/aqua to gray shades, the low cloud features are developing over the central CONUS while being sandwiched between Spring-time cyclones in the East and West.  The massive spreading of the stratus and fog can’t be missed and numerous METAR observations across the central CONUS verified the aviation hazards.

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Figure 1. Nighttime Microphysics RGB from GOES-16 at 0602 to 0957 UTC on 28 March 2017 over the U.S.

For the above and subsequent images/animations: NOAA’s GOES-16 satellite has not been declared operational and its data are preliminary and undergoing testing. Users receiving these data through any dissemination means  (including, but not limited to, PDA and GRB) assume all risk related to their use of GOES-16 data and NOAA disclaims any and all warranties, whether express or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose.

Focusing on the Tennessee and Lower Mississippi Valley regions, the fast motion of the animation from 0900 to 1130 UTC allows one to see the development of fog while other stratus clouds  pass to the east/northeast (Fig 2.).  Note that fog develops in the various low-lying areas, particularly eastern Tennessee valleys.  There is also a separate push of fog, noted by the black dotted oval of Figure 3, that moves southward along the back side of the eastern cyclone.  The METAR stations in the oval show the lowest visibility observations occurring in this area of southern and western Tennessee as well as northern Alabama.  A bit further upstream (north) from the push of fog there is a layer of very low stratus also moving southward and causing MFVR to IFR conditions.  With the large amount of precipitation from the previous day and relatively light winds overnight, a variety of fog and stratus developed over a wide area as the cyclone passed.  While not extremely common there are instances where fog develops even with  low stratus present overhead.  One can see this in central Missouri where fog is reported but the RGB shows stratus with large water droplets at their tops.  Fog below stratus was experienced at times in northern Alabama as well.

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Figure 2. Nighttime Microphysics RGB from GOES-16 at 0902 to 1122 UTC on 28 March 2017 centered over western Tennessee and covering the Tennessee and Upper Mississippi Valleys.

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Figure 3. METAR station plot from the Aviation Weather Center ADDS site (left) and the Nighttime Microphysics RGB.  Both from near 1100 UTC with annotations of fog and stratus locations and movement.  Blue arrow in METAR shows direction of movement and shared black dotted oval notes locations of lowest visibility reports.

SPoRT-created training material now available via the new AIR Tool within AWIPS

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Training material now available for use by NWS forecasters via the new AIR tool within AWIPS. This example shows the SPoRT-created Nighttime Microphysics RGB Quick Guide.

NASA SPoRT has been working to get training materials available to NWS forecasters via the new AWIPS Integrated Reference (AIR) tool.  This Twitter post and attached video details how NWS forecasters can access the new training material.  This training is now available with the current POES RGB imagery, but will also be available once RGB imagery from GOES-16 is available in AWIPS. SPoRT will be working to add new training content within Vlab and accessible via the AIR tool in the coming months.

GOES-16 Air Mass RGB and NUCAPS Soundings

SPoRT has worked closely with the GOES-R and JPSS Proving Grounds to explore innovative applications for the Air Mass RGB and CrIS/ATMS NUCAPS Soundings.  Specific applications include identification of stratospheric air influence and tropopause folding to anticipate rapid cyclogenesis and hurricane tropical to extratropical transition.

When the Air Mass RGB was first introduced to NOAA NWS National Center forecasters in 2012, SPoRT developed a total column ozone product from the NASA AIRS instrument (a hyperspectral infrared sounder) as a way to help forecasters gain confidence in interpreting the qualitative RGB.  Since that time SPoRT has continued to develop quantitative ozone products such as the ozone anomaly and tropopause height products from additional hyperspectral infrared sensors such as CrIS/ATMS and IASI.

More recently, CrIS/ATMS NUCAPS Soundings were added to AWIPS-II for forecasters to utilize in operations.  SPoRT has specifically explored the utility of NUCAPS Soundings for hurricane tropical to extratropical transition (see link to training material).   With the availability of the GOES-16 Air Mass RGB and NUCAPS Soundings in AWIPS-II there is an opportunity to explore rapid cyclogenesis cases and extratropical transition events with next-generation satellite capabilities.  Since we have the capability to display the client-side generated Air Mass RGB here at SPoRT, here is a quick preview of how the NUCAPS Soundings can be used to compliment the Air Mass RGB.

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GOES-16 AWIPS-II client-side generated Air Mass RGB 3 March 1817 UTC

Please note, the GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized.

The Air Mass RGB is able to detect temperature and moisture characteristics in the mid- to upper levels of the atmosphere.  Warm, dry air upper level air appears in red/orange tones. Dry upper level air appears more red when associated with anomalous potential vorticity as warm, dry, ozone-rich air is pulled downward by the jet stream circulation.   Dry upper levels away from the jet stream appear orange. In contrast warm, moist tropical air appears in green tones, appearing more olive when less moisture is present.

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Air Mass RGB interpretation guide adapted from EUMETSAT (Zavodsky et al. 2013)

In the Air Mass RGB image above you can see a well-defined upper-level temperature and moisture boundary across the southern U.S. associated with yesterday’ s passing frontal system.  NUCAPS Soundings can provide additional information about the thermodynamic and stability characteristics of the lower-levels of the atmosphere which cannot be deciphered in the Air Mass RGB.  The Sounding at Location 1 shows a mostly dry atmospheric column, which is typical for the orange colored regions (i.e dry upper levels) in the RGB, note however there are moister conditions around 850 mb.    The Soundings at Location 2 and 3 in the green colored regions (i.e. moist upper levels)  confirm moist upper-level conditions.  What the NUCAPS Soundings reveal is a layer of much drier mid-level air between about 850-400 mb, which cannot be detected in the Air Mass RGB.  The ability to detect such a layer can be important in data sparse regions.  Although this is a benign weather situation where much of the Southeast enjoyed sunny, cool, and dry conditions today, this same technique can be applied to more intense, high impact events to assess the thermodynamic environment surrounding a developing low pressure system or weakening hurricane where moist or dry layers can have an impact on storm intensity.

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AWIPS-II CrIS/ATMS NUCAPS Sounding 3 March 2017 1817 UTC at Location 1

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AWIPS-II CrIS/ATMS NUCAPS Sounding 3 March 1817 UTC at Location 2

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AWIPS-II CrIS/ATMS NUCAPS Sounding 3 March 2017 1817 UTC at Location 3

 

For more information regarding the Air Mass RGB, including applications and interpretation guides for the color features in the imagery:

The Nighttime Microphysics RGB from GOES-16 ABI

The Nighttime Microphysics (NtMicro) RGB imagery provides multiple cloud characteristics of thickness, particle phase/size, and height within a single image in order to analyze cloud features. Below is an example of the NtMicro RGB from the full disk scans taken every 15 minutes.

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Nighttime Microphysics RGB from GOES-16 from 0610 UTC to 1225 UTC on 3 March 2017.

 

Please note, the GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized.

The NtMicro RGB imagery (below) over Florida in the early morning of 3 March 2017 show a variety of clouds in the scene.  In southern Florida, various shades of aqua represent low, water clouds where surface observations indicated ceilings of 1000-1500 ft (MVFR conditions).  Slightly further north in central Florida, cloud tops are represented by more tan/yellowish coloring with the RGB representing thicker, colder clouds with larger particles.  This suggests clouds that are a bit higher above the ground.  Continuing northward the cloud features are seen streaming to the east, northeast.  These clouds have mostly dark coloring suggesting little contribution from all the color components (red, green, blue).  The purple clouds are thin, mid-level clouds with ice.  One can tell that the clouds are thin because the underlying surface (land vs water) influences the resulting shade of color as the cloud passes over.  The dark blue is very thin, cold cirrus clouds while the dark red represents similar cirrus clouds but with slightly thicker characteristics.  Also note that some bright red clouds appear over the Gulf Stream (right side of image) representing very thick, cold ice tops of convection.   Overall, quite a number of cloud features can be seen in this IR-based RGB in a very efficient product.

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Nighttime Microphysics RGB over Florida from GOES-16 0701 UTC to 1156 UTC on 3 March 2017. Aqua colored clouds depicting impacts to TAF sites experiencing MVFR ceilings.

 

Please note, the GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized.

For more information regarding the Nighttime Microphysics RGB, including interpretation guides for the color features in the imagery:

SPoRT Quick Guide: Nighttime Microphysics RGB in the SPoRT Training Site

SPoRT Nighttime Microphysics RGB Fundamentals (Module) ~20 minutes

AGU EOS Project Update: Transforming Satellite Data to Weather Forecasts

GOES-16 Advanced Baseline Imager Day 2: Loops!

Today GOES-16 data started flowing over the AWIPS Satellite Broadcast Network (SBN/NOAAPort) data feed.  SPoRT is able to ingest this data into a test AWIPS system to view and analyze the imagery.  Over the past several years, SPoRT has had an active role in transitioning proxy GOES-R multispectral (i.e. RGB) imagery derived from polar-orbiting sensors to prepare NWS offices and National Centers for advanced capabilities available with GOES-16.  Below is animation of the Air Mass RGB in which forecasters can use to analyze temperature and moisture characteristics surrounding synoptic scale systems and stratospheric air intrusions to anticipate rapid cyclogenesis. Warm, dry, ozone-rich upper level air with anomalous potential vorticity can be identified in tones or orange and red and indicate the potential for stratospheric air influence on a developing cyclone (see interpretation guide below). Although this RGB is not available to NWS forecasters today, SPoRT is working with the Total Operational Weather Readiness – Satellites (TOWR-S) team to transition the capability to derive client side RGBs in AWIPS-II to NWS offices.

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2 March 2017 AWIPS II Client Side dervied Airmass RGB 2011 UTC to 2131 UTC

Please note, the GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized.

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Interpretation guide for the Air Mass RGB, adapted from the EUMETSAT (Zavodsky et. al 2013)

For more information regarding the Air Mass RGB, including interpretation guides for the color features in the imagery:

Recalling our blog post from yesterday, we had a loop that showed  an hour long loop of data every 5 minutes from the ABI as severe storms moved through the north Alabama area. We spent more time going over all the data received through the GOES Rebroadcast (GRB) data transmission system receiver located here at NASA Marshall Space Flight Center in Huntsville, Alabama. Below is a loop of higher temporal resolution (1 minute) data from the same storm system using one of the GOES-16 mesoscale domains.

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One minute imagery from Band 2 of the GOES-16 Advanced Baseline Imager (ABI) taken during the early afternoon on 1 March 2017.

Please note, the GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized.