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Archive for the ‘CrIS’ Category

CrIS/ATMS soundings processed through the NOAA Unique Combine Processing System (NUCAPS) are available in AWIPS.  SPoRT is working with the Joint Polar Satellite System (JPSS) Proving Ground to testbed the utility of NUCAPS soundings to anticipate hurricane tropical to extratropical transition.  Although satellite derived soundings are “smoother” than radiosondes they can provide valuable information about the depth of moist or dry layers in data sparse regions. Forecasters can anticipate extratropical transition by identifying the dry slot and upstream potential vorticity anomalies on satellite imagery that may interact with a storm while also considering many other factors that lead to extratropical transition.  Although Hurricane Matthew is not expected to undergo extratropical transition for quite a few days, the NUCAPS Soundings can be used to diagnose the temperature and moisture characteristics surrounding the hurricane as highlighted below.

GOES-13 water vapor imagery shows dry upper levels west of Hurricane Matthew and abundant moisture surrounding the system (Fig. 1).  Since water vapor imagery can only detect moisture characteristics in the mid-to upper- levels of the atmosphere, the NUCAPS soundings (green dots on Fig. 1) can be analyzed to provide more information about the vertical extent of the dry air and whether it is in close proximity to the hurricane in the mid- to lower- levels.

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Fig. 1. 5 October 2016 1830 UTC GOES-13 water vapor imagery and 1811 UTC NUCAPS Soundings. Green dots represent point and click soundings. Blue numbers label location of example soundings highlighted below.

Scroll down through the example Soundings to compare the changes in moisture conditions west of Hurricane Matthew. Soundings 1 and 2 (Fig. 2 and 3), taken in a region of dry air as identified by the orange color enhancement on the water vapor imagery, confirm a dry column throughout the depth of the atmosphere. Sounding 3 (Fig. 4) shows the drying is not as intense in the upper-levels and mid-level drying extends down to about 600 mb. Sounding 4 and 5 (Fig. 5 and 6) show upper level conditions are more moist closer to the hurricane, as expected from the water vapor imagery. While Sounding 4 (Fig. 5) shows moist conditions throughout the atmospheric column, Sounding 5 (Fig. 6) does show mid-level dry air is present.  Previous analysis of Sandy 2012 and Arthur 2014 showed the same signature (e. g., similar to Sounding 5) became more abundant surrounding the systems as upper-level dry air intruded.  Currently, there are very few soundings with this signature surrounding Hurricane Matthew.  The NUCAPS soundings confirm dry atmospheric conditions are well west of the system and there is very little mid- to low- level dry air in the proximity of the system.  This preliminary example is presented but as Hurricane Matthew continues to evolve NUCAPS Soundings and SPoRT Ozone Products will be analyzed to discern the utility for anticipating dry air intrusion and associated hurricane tropical to extratropical transition.

Sounding 1

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Fig. 2. 5 October 2016 1811 UTC NUCAPS Sounding at Location 1.

 

Sounding 2

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Fig. 3. 5 October 2016 1811 UTC NUCAPS Sounding at Location 2.

Sounding 3

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Fig. 4. 5 October 2016 1811 UTC NUCAPS Sounding at Location 3.

Sounding 4

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Fig. 5. 5 October 2016 1811 UTC NUCAPS Sounding at Location 4.

Sounding 5

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Fig. 6. 5 October 2016 1811 UTC NUCAPS Sounding at Location 5.

 

 

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So, recently I’ve had the opportunity to use and evaluate soundings from the NOAA Unique Combined Atmospheric Processing System (NUCAPS).  These soundings, produced by the ATMS and CrIS instruments onboard the Suomi NPP satellite, are available in AWIPS generally twice per day over any given location.

NUCAPS_exampleswath

Image 1.  NUCAPS Sounding data availability example, ~19 UTC 24 July 2016. Colors represent quality control flags — green are considered best available and most representative data.

A couple of advantages of the NUCAPS soundings is they’re available in relatively high spatial resolution (image 1) and also in between radiosonde launches.  So, a forecaster wanting to know more about tropospheric conditions during the midday or early afternoon (usually the most crucial period for severe weather analysis) can utilize NUCAPS sounding data, since radiosonde data won’t be available until later in the evening (unless ~18 UTC launches are being conducted at their location).  On a number of days in recent weeks, a lack of sufficient boundary layer moisture (probably partly due to an ongoing drought in the region) have dampened convective development.  A good understanding of the degree of convective inhibition (CIN) present on a given day can be difficult to obtain and model analyses and forecasts don’t always seem to have a good handle on this.  Even other robust analyses often struggle with a seemingly accurate depiction of CIN on many days.  However, knowledge of CIN, among other factors, can be important when forecasting probabilities for convective development on summer days.

Recently however, I’ve noticed that NUCAPS soundings did indicate the presence of CIN when convective development was perhaps less than expected or forecast.  July 20th was one of these days.  Take a look at the NAM Bufr Sounding for HSV, valid for 19 UTC on 20 July 2016 (image 2).

NAMBufr_HSV_20July2016_19Z_cropped

Image 2.  NAM Bufr Sounding for KHSV, 19 UTC 20 July 2016

The NAM Bufr model sounding indicated robust CAPE values (generally >2500 J/Kg) and little to no CIN.  Now, let’s take a look at a couple of nearby representative NUCAPS soundings (unfortunately, they don’t include the associated data tables).  Image 3 shows the locations of the NUCAPS soundings with respect to the KHSV observation site and the location in the NAM forecast sounding above (image 2).

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Image 3.  NUCAPS Sounding locations for image 4…also, the KHSV location in northern Alabama

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Image 4.  NUCAPS Soundings at 19 UTC for location A (left, west of KHSV) and location B (right, southwest of KHSV), 20 July 2016

Even though data tables are not shown from the NUCAPS soundings, notice that they indicate much less instability and less steep lapse rates than the NAM Bufr sounding prognostications for the same time (19 UTC).   Also, notice that LCL levels are below the LFC, indicating some amount of CIN at both locations.  If memory serves correctly, NUCAPS soundings indicated CIN values around 25-50 J/Kg at this time.  So, for a forecaster struggling with the likelihood/coverage of convective development and the strength of convective updrafts, the NUCAPS data would have suggested lesser magnitude for both, over the NAM progs.  Image 5 shows the general dearth of convective activity in the area of northern Alabama near 19 UTC that day.  And indeed, convection was generally limited through the afternoon, with mostly isolated, small cells present.

CompRefl_NUCAPSLocations_20July2016_1856Z

Image 5. Composite reflectivity (dBZ) at 1830 UTC 20 July 2016

When viewing the NUCAPS soundings, I’ve generally been looking for CAPE/CIN values while in the convective season.  Of course, having to click on a number of soundings can be a bit laborious.  As part of a JPSS Proving-Ground/Risk Reduction multi-organization project, researchers at CIMSS, CIRA, GINA and NASA SPoRT have developed gridded NUCAPS data, which were utilized in the Hazardous Weather Testbed this past spring.  I’ll be working with members of the SPoRT team to ingest those data in AWIPS II here at the HUN office in the near future for my own testing, evaluation and feedback to the NUCAPS group within the JPSS Proving Ground.  I’m looking forward to the future use and evaluation of these potentially useful operational data sets.

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Gridded NUCAPS products developed as part of a multi-organization JPSS PG/RR project are currently being evaluated at the Hazardous Weather Testbed (HWT) Experimental Warning Program (EWP).  The project contains contributions by researchers from UW/CIMSS, CSU/CIRA/ UAF/GINA, and SPoRT.  NUCAPS soundings are retrieved temperature and moisture soundings from the Suomi-NPP CrIS and ATMS sounders.  The evaluation of NUCAPS at HWT is aimed at providing upper air temperature and moisture information in the pre-convection environment to better understand variables that are necessary for convection and severe weather.  The Gridded NUCAPS products allows for isobaric plan views of temperature and moisture that forecasters can use to gain confidence in the model output

Forecasters at the HWT-EWP posted some input on the use of the Gridded NUCAPS products.  On the Satellite Proving Ground at HWT Blog (http://www.goesrhwt.blogspot.com/2016/04/nucaps-planviews.html), a forecaster noted:

“[Gridded NUCAPS] would be beneficial in the forecasting environment as added temperature data would be available in between standard upper-air launches.  This could serve as a good proxy to help judge the strength of a capping inversion, while also possibly serving as an additional information source during winter wx events.

However, the forecaster also noted that the amount of missing data included in the product limits its utility.  Currently, the Gridded NUCAPS contains only the highest quality (i.e., “best”) data that comes from a combination of both microwave and infrared (top image below).  In this image, the dark blue pixels represent the data that are discarded due to QC issues.  However, this quality control can be strict at times and leave out “good” data that can still be useful to the forecasters.  When these “good” data are included, there are much more useful data (bottom image below) without any noticeable discontinuities or oddities in the data.

SPoRT plans to use the feedback from HWT-EWP participants to test pushing the inclusion of the “good” quality data to the Gridded NUCAPS product to provide forecasters with more data for their analysis.

NUCAPS.2016.04.21.1902329.853mbtemp_QCeq1

853 hPa Gridded NUCAPS temperature product from 21 April 2016 at 1902 UTC including only the highest quality flags.  Dark blue pixels denote discarded data that results in data gaps.  Note that a lot of over-land observations are discarded.

NUCAPS.2016.04.21.1902329.853mbtemp_QCle2

853 hPa Gridded NUCAPS temperature product from 21 April 2016 at 1902 UTC including both “best” and “good” quality flags.  Dark blue pixels denote discarded data.  Missing pixels generally correspond to thick cloud features.

 

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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.

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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)

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Author: Emily Berndt

This week NASA SPoRT began producing and disseminating real-time Cross-track Infrared and Microwave Sounding Suite (CrIMSS) ozone products to the Ocean Prediction Center, Weather Prediction Center, and Satellite Analysis Branch. CrIMSS retrievals are a combination of retrievals from the Cross-track Infrared Sounder (CrIS) and Advanced Technology Microwave Sounder (ATMS) instruments aboard the NOAA/NASA Suomi NPP satellite which is our Nation’s next generation polar-orbiting operational environmental satellite system. Since CrIS is an infrared sounder its ability to detect atmospheric variables through cloudy regions is limited, therefore the retrievals are combined with ATMS retrievals to view atmospheric variables in partly cloudy regions. Despite the use of microwave retrievals, retrievals are still degraded or blocked by thick clouds, similar to AIRS. Recall AIRS infrared retrievals are also combined with microwave retrievals from the Advanced Microwave Sounding Unit (AMSU) to overcome this limitation of the infrared sounder.

Expanding the ozone products to included CrIMSS retrievals will provide National Center forecasters with additional retrievals to evaluate for identifying stratospheric air related to forecasting rapid cyclogenesis and high-wind events.

While the CrIMSS algortihm differs from AIRS, the creation of ozone products using CrIMSS is the first step to expanding SPoRT’s ozone products to the next generation instrumentation aboard the Suomi NPP satellite. There are slight variations in the retrievals, but decent agreement in ozone concentration is observed between AIRS and CrIMSS retrievals. Retrievals processed via The NOAA Unique CrIS/ATMS processing System (NUCAPS) are planned for release this summer. NUCAPS is a version of the AIRS Science Team Algorithm. Once SPoRT has access to the NUCAPS retrievals the CrIS ozone product will be updated. The advantage of the NUCAPS retrievals will be the the ability to directly compare the AIRS and CrIS/ATMS ozone retrievals across satellite platforms/instruments and provide forecasters with greater spatial and temporal coverage.

The four images below are an example of consecutive AIRS and CrIMSS ozone retrievals now available to forecasters in N-AWIPS format.

1400 UTC 14 May 2014 AIRS Total Column Ozone

1400 UTC 14 May 2014 AIRS Total Column Ozone

1500 UTC 14 May 2014 CrIMSS Total Column Ozone

1500 UTC 14 May 2014 CrIMSS Total Column Ozone

1600 UTC 14 May 2014 AIRS Total Column Ozone

1600 UTC 14 May 2014 AIRS Total Column Ozone

1700 UTC 14 May 2014 CrIMSS Total Column Ozone

1700 UTC 14 May 2014 CrIMSS Total Column Ozone

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Level 2 retrieved temperature and moisture profiles in clear and partly cloudy conditions can be obtained from the new Cross-track Infrared Microwave Sounding Suite (CrIMSS), which uses infrared measurements from the Cross-track Infrared Sounder (CrIS) and microwave measurements from the Advanced Technology Microwave Sounder (ATMS).  These observations are available from the Suomi-NPP as operational legacy observations to those coming on the JPSS.

SPoRT has begun processing the 42-level temperature and 22-level moisture CrIMSS Environmental Data Record (EDR) data and qualitatively comparing these soundings to other hyperspectral sounders (AIRS and IASI), in situ observations (RAOBs), and regional models (North American Mesoscale (NAM) and Rapid Refresh (RAP)).  All of these comparisons are available on SPoRT’s hyperspectral sounding comparison page (http://weather.msfc.nasa.gov/sport/hyperspectral_comparisons/).

As an example of these comparisons, the three images below were taken from that webpage for soundings at Vandenberg Air Force Base (VBG) in California all valid around 2100 UTC on 31 March 2013.  Note that the CrIMSS and AIRS soundings both match very closely to the RAP temperature sounding with near-perfect agreement of tropopause height in the AIRS sounding and similar tropopause placement in the CrIMSS sounding.  Both the AIRS and CrIMSS soundings highlight a low-level moist conditions and mid-level dry conditions.  Satellite soundings in this form can be used by forecasters to gain additional confidence in their model guidance or obtain additional information in regions where there are not other upper air observations (such as over Northern Mexico and the Gulf of Mexico).

Temperature and dew point soundings at VBG at 2100 UTC on 31 March 2013.

Temperature and dew point soundings at VBG at 2100 UTC on 31 March 2013.

Temperature and dew point soundings from CrIMSS at VBG at 2100 UTC on 31 March 2013.

Temperature and dew point soundings from CrIMSS at VBG at 2100 UTC on 31 March 2013.

Temperature and dew point soundings from AIRS at VBG at 2100 UTC on 31 March 2013.  Thicker line indicates highest quality data.

Temperature and dew point soundings from AIRS at VBG at 2100 UTC on 31 March 2013. Thicker line indicates highest quality data.

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The Northeast is bearing down for a blizzard as two storm systems are expected to merge off the East Coast early Saturday morning. Currently, one low pressure center is near Lake Erie and the other one is off the Virginia coast (see surface map below). Once the two systems phase off the East Coast, the new system is expected to rapidly deepen to 970 mb. Blizzard conditions will result as 1-2 feet of snow falls and winds gust to as high as 70 mph.

HPC 1500 UTC Surface Analysis Feb. 8, 2013

HPC 1500 UTC Surface Analysis Feb. 8, 2013

From a satellite perspective, how can some of the new GOES-R imagery and AIRS profiles help identify significant features associated with this unique synoptic set up? Below is an RGB Air Mass image from 0634 UTC this morning. The image gives a clear view of the coastal storm. Notice the green colors to the south of the main cloud shield, indicated by a blue arrow. The green colors represent warm, moist tropical air that is being drawn into the storm.  This air mass will provide abundant moisture to produce the robust snow fall amounts expected. A VIIRS/CRiS RGB Air Mass image from 0733 UTC this morning gives a broader view of the Eastern United States and shows the structure of both storms. The storm situated over the Great Lakes will usher cold air into the Northeast. There are also green colors to the north and northwest of the Great Lakes storm however they indicate cold, moist air.

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NASA SPoRT Aqua MODIS RGB Air Mass Image  0634 UTC Feb. 8, 2013.
Yellow arrow points to ozone rich stratospheric air and Blue arrow points to warm, moist tropical air.

NASA SPoRT VIIRS/CRiS RGB Air Mass Image     0733 UTC Feb. 8, 2013.
Yellow arrow points to ozone rich stratospheric air

Stratospheric intrusions are commonly associated with rapidly developing cyclones and may be responsible for transporting higher momentum air to the surface to produce damaging winds at the surface. If we piece together information from the RGB Air Mass imagery, AIRS total column ozone, and a 300 mb map, can we find an explanation to why this system will be associated with strong wind gusts?  The 1200 UTC 300 mb observations, pictured below, show a 125 kt jet streak north of Maine. The red/orange colors in the MODIS RGB Air Mass imagery indicate the presence of a jet streak and high potential vorticity air.  The AIRS total column ozone, pictured below, indicates higher values of ozone in the same vicinity. The presence of high potential vorticity air and larger amounts of ozone signify higher momentum stratospheric air intruding into the troposphere. Some of this stratospheric air is being drawn into the Great Lakes storm, shown by the yellow arrows on the VIIRS/CRiS RGB Air Mass image. Unfortunately  there was not an AIRS pass to the east of the storm system to further confirm ozone-rich stratospheric air. As the system continues to progress, more AIRS data and RGB Air Mass data will be investigated to watch how stratospheric air is drawn into the storm and how it relates to the production of surface wind gusts.

300 mb Heights (dm) and Isotachs (kts) 1200 UTC Feb. 8, 2013. Image from NCAR RAL Real Time Weather Data website

AIRS Total Column Ozone 0630-0636 UTC            Feb. 8, 2013

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