NUCAPS Soundings available in AWIPS II

June 10th, 2014 |
Suomi/NPP VIIRS 11.45 µm IR channel and NUCAPS sounding points (click to enlarge)

Suomi/NPP VIIRS 11.45 µm IR channel and NUCAPS sounding points (click to enlarge)

NOAA Unique Cross-track Infrared Sounder (CrIS)/Advanced Technology Microwave Sounder (ATMS) Processing System (NUCAPS) Soundings have started flowing into AWIPS-2 at NWS WFOs across the country. These soundings offer high spectral (and high spatial) resolution soundings derived from the CrIS and ATMS instruments that fly on the Suomi/NPP satellite. The toggle above shows the footprint of the soundings in comparison to an 11.45 µm VIIRS instrument (also on the Suomi/NPP satellite) IR image from approximately 1800 UTC on 10 June 2014. The NUCAPS soundings cover a larger area because they are processed by NOAA/NESIS (vs. being downloaded on the X-Band Direct Broadcast antenna at CIMSS in Madison WI, whose antenna is the source of the VIIRS 11.45 µm IR image shown).

The sounding data, if available, are under the ‘Satellite’ menu tab of AWIPS-2, and then NPP Products can be selected to view NUCAPS Sounding Availability, as shown in this screenshot. Once the sounding locations are loaded, the mouse can be used to select a point, and a left click produces a sounding in an NSharpEditor environment; that is, you can edit it (if, for example, you think the surface dewpoint in the sounding is too dry).

The mid-continent overpass at around 1800 UTC can provide valuable information on the possibility of convective development. For example, consider the visible imagery below from 1915 UTC on May 29 2014. Will convection develop out of that broken cumulus field as forecast by the GFS (not shown)?

GOES-13 0.63 µm Visible Imagery, 1915 UTC 29 May 2014 (click to enlarge)

GOES-13 0.63 µm Visible Imagery, 1915 UTC 29 May 2014 (click to enlarge)

The animation below steps through the Suomi/NPP overpass just after 1800 UTC that was used to created NUCAPS soundings on that day, followed by a close-up over Omaha, then a screen-capture of the created sounding. The sounding (which includes surface values close to those reported by the METAR) has only modest values of Convective Available Potential Energy (CAPE), suggesting that convection is unlikely. And, indeed, visible imagery near sunset shows dissipating cumulus clouds.

NUCAPS Sounding over North America, over Omaha and surroundings, and the individual NUCAPS sounding indicated (Courtesy of Dan Nietfeld, SOO at Omaha/Valley WFO, click to enlarge)

NUCAPS Sounding over North America, over Omaha and surroundings, and the individual NUCAPS sounding indicated (Courtesy of Dan Nietfeld, SOO at Omaha/Valley WFO, click to enlarge)

A second case, below, also from Dan Nietfeld, shows NUCAPS soundings before the devastating hailstorm on June 3 in a High Risk region. In this case, the NUCAPS soundings underestimated the temperature/dewpoint at the surface, but the editable sounding software makes quick work of adjusting the lowest part of the sounding, and the CAPE in the adjusted sounding increased from 1800 to more than 3000. (The location of the sounding is shown here; it is the southern of the two circled green dots.) NUCAPS data underscores the potential of any convection.

NUCAPS soundings, original and adjusted, 1849 UTC on 3 June (click to enlarge)

NUCAPS soundings, original and adjusted, 1849 UTC on 3 June (click to enlarge)

(Click here for further information on ATMS; Click here for further information on CrIS). Many thanks to Dan Nietfeld, SOO at Omaha, for imagery above. Hyperspectral Soundings are described in a COMET module that can be viewed here. A paper (pdf format) describing validation of NUCAPS soundings is available here. Suomi/NPP support is provided in part by the NOAA/NESDIS Joint Polar Satellite System (JPSS) program.

Tropical Storm Beryl forms in the Atlantic Ocean

July 5th, 2018 |

GOES-16 Band 2 (“Red Visible”, 0.64 µm) Imagery over the Atlantic Ocean, 0915-2130 UTC on 5 July 2018 (Click to animate)

The season’s second named tropical cyclone in the Atlantic Basin has formed.  GOES-16 visible imagery, above (click to play an animated gif), shows Tropical Storm Beryl moving westward just north of 10 º N Latitude between 40 º and 50 º W Longitude.  The infrared imagery (10.3 µm), the Clean Window, below shows a compact storm with cold cloud tops and a central dense overcast.

GOES-16 Band 13 (“Clean Window”, 10.3 µm) Infrared Imagery over the Atlantic Ocean, 0915-2130 UTC on 5 July 2018 (Click to animate)

Much of the tropical Atlantic north of 10 N Latitude shows little convection.  This is because of a Saharan Air Layer, shown below (in red) from a screen capture from the CIMSS Tropical Website (Click here for the latest SAL analysis). An important component of the SAL analysis is the Split Window Difference field (10.3 µm – 12.3 µm) that can diagnose both moisture and dust. The SAL analysis shows considerable dry Saharan air over the Atlantic; Beryl has formed along its southern edge. Compare the SAL analysis to the Split Window Difference field, below, that shows dry air in blue. Similar features are present in both. The GOES-16 Low-Level Water Vapor Infrared Imagery (7.34 µm), here, shows similar features as well. There are multiple ways to diagnose dry air with GOES-16.

Saharan Air Layer (SAL) Analysis, 2100 UTC on 5 July 2018 (Click to enlarge)

GOES-16 Split Window Difference field (10.3 -12.3 µm) Imagery over the Atlantic Ocean, 2100 UTC on 5 July 2018 (Click to enlarge)

NUCAPS Soundings from Suomi NPP can be used to diagnose the thermodynamics of the atmosphere surrounding Beryl. The image below shows NUCAPS Soundings locations between 1500 and 1600 UTC on 5 July 2018, and the points are color-coded to describe the data (as discussed here). A Sounding near 16.3 N, 43.1 W (north of Beryl) shows dryness at mid-levels; total precipitable water is only 1.27″. A Sounding closer to the storm, at 10.3 N, 43.5 W (west of Beryl) is much wetter: total precipitable water is 2.12″. NUCAPS Soundings are available online (over the Continental US only) here.

NUCAPS sounding locations over Beryl at 1500-1600 UTC on 5 July 2018 (Click to enlarge)

Very small (in size) Beryl is forecast to strengthen in the short term. See the National Hurricane Center website and the CIMSS Tropical Website for more information.


==== Update 6 July 2018 ====
Beryl has strengthened and is a hurricane, as of 0900 UTC on 6 July, the first hurricane of the 2018 Atlantic Hurricane season. The sandwich product animation below, courtesy Rick Kohrs and Joleen Feltz, CIMSS, that combines visible (0.64 µm) and clean window infrared (10.3 µm) imagery shows the appearance and subsequent disappearance of a very small eye.

Sandwich product that combines GOES-16 Band 2 (“Red Visible”, 0.64 µm) and Band 13 (“Clean Window”, 10.3 µm) over Beryl, 0815-1515 UTC on 6 July 2018 (Click to enlarge)

Gravity waves (and a land breeze boundary) in the Gulf of Mexico

November 22nd, 2016 |

GOES-13 Visible (0.63 µm) images, with hourly surface/buoy/ship reports [click to play animation]

GOES-13 Visible (0.63 µm) images, with hourly surface/buoy/ship reports [click to play animation]

GOES-13 Visible (0.63 µm) images (above) revealed a series of gravity waves propagating southeastward across the Gulf of Mexico on 22 November 2016. These waves appeared to be moving through or along the tops of the marine boundary layer stratocumulus cloud field; since the hourly winds from surface/buoy/ship reports were  generally from the southeast/east/northeast, these gravity waves were not likely surface-based.

Also of note was an apparent land breeze boundary that moved west-northwestward away from the Yucatan Peninsula of Mexico during the day.

Suomi NPP VIIRS Visible (0.64 µm) image, with NUCAPS sounding locations and surface analysis [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm) image, with NUCAPS sounding locations and surface analysis [click to enlarge]

Gravity waves like those observed here are usually ducted within a strong air temperature inversion — so Suomi NPP NUCAPS (NOAA-Unique CrIS/ATMS Processing System) soundings around 1828 UTC (above) were examined for evidence of such an inversion. Training material for NUCAPS Soundings in AWIPS is available here.

One of the NUCAPS vertical profiles of temperature and moisture is shown below, for a point over the southern Gulf of Mexico (designated by the cyan rectangle, approximately 50 miles northwest of the coast of the Yucatan Peninsula) — several of the waves had passed through this location prior to the image time. A well-defined temperature inversion did indeed exist aloft, within the 1-2 km layer above the surface (and just above the top of the moist marine boundary layer, where the stratocumulus cloud field existed). It therefore appears likely that this series of southeastward-moving gravity waves was mildly perturbing the tops of the stratocumulus clouds.

NUCAPS sounding profile for a point over the Gulf of Mexico, north of the Yucatan Peninsula [click to enlarge]

NUCAPS sounding profile for a point over the Gulf of Mexico, north of the Yucatan Peninsula [click to enlarge]

Since there were no nearby surface frontal boundaries or areas of organized deep convection inland over the southern US during the preceding 24 hours, it is unclear as to what may have been the catalyst for these gravity waves.

Severe Weather in the Pacific Northwest

October 15th, 2016 |

Window Channel Infrared imagery from COMS-1 (10.8 µm) and GOES-15 (10.7 µm), every 6 hours from 1200 UTC on 7 October through 1800 UTC on 15 October [click to animate]

Infrared Window Channel imagery from COMS-1 (10.8 µm) and GOES-15 (10.7 µm), every 6 hours from 1200 UTC on 7 October through 1800 UTC on 15 October [click to animate]

Strong moisture-laden storms caused abundant precipitation and severe weather over the Pacific Northwest from 13-15 October 2016. The animation above shows two storms making landfall in the Pacific Northwest, one on 13-14 October and a second, on 15 October, which was a storm that originated from the remnants of Typhoon Songda. On 11-12 October, Super Typhoon Songda was recurving, subsequently racing towards the west coast of the United States, and making landfall as a strengthening extratropical cyclone on 15 October. The animation above uses two different satellites (COMS-1 and GOES-15), and includes a seam between the two views because the spectral characteristics of the two infrared window bands are not identical.

Daily precipitation from the Advanced Hydrologic Prediction Center from 13-15 October is shown here, with a weekly total shown below. A large area of precipitation exceeding 6 inches is apparent in the higher terrain.

ahps_7dprecip_15oct_1200

7-day Precipitation Totals ending 1200 UTC on 15 October 2016 (Click to enlarge)

The precipitation amounts were aided by the very moist airmass that accompanied the storms. Total Precipitable Water, shown below, from this site that manipulates data from here, shows the moisture. A larger-scale view that traces the moisture back to the time when Songda first reached typhoon intensity over the West Pacific is available here.

Total Precipitable Water, 12-15 October 2016 [Click to animate]

The strong storm before the one spawned by the remnants of Songda produced an EF2-rated tornado in Manzanita Oregon (YouTube Compilation; SPC Storm Reports; Blog post with damage picture) on 14 October 2016. GOES-15 Visible Imagery, below, shows a storm with overshooting tops moving over northwestern Oregon at the time of the tornado. (GOES-15 was performing a full-disk scan from 15:00-15:26 UTC, so 15-imagery was not available as the tornado moved ashore; the Advanced Baseline Imager on GOES-R will produce CONUS Imagery every 5 minutes in addition to Full-Disk Imagery every 15 minutes). The overshoots are especially apparent in the 1500 and 1530 UTC Images. GOES-13 provided a visible image at about the time of the tornado touchdown, but at a very oblique angle. The cirrus shield of the thunderstorm anvil is apparent, however.

GOES-15 Visible (0.62 µm) imagery, 1445, 1500 and 1530 UTC on 14 October. The Red Square indicates the tornado location [Click to animate]

GOES-15 Infrared Window (10.7 µm) imagery around the time of the severe weather in Oregon, below — which includes locations of SPC storm reports of tornadoes (red) and damaging winds (cyan) — also showed evidence of cold overshooting tops (the coldest clouds tops were around -50º C, yellow enhancement). An infrared image animation showing only the clouds is available here. NOAA-18 flew over the Oregon coast at 1427 UTC, and the AVHRR 12 µm Infrared image showed the parent thunderstorm offshore, upstream of Manzanita (larger-scale view).

GOES-15 Infrared Window (10.7 µm) imagery, 1400-1800 UTC on 14 October [Click to animate]

The Portland, Oregon NWS office issued 10 tornado warnings on 14 October — a record number for a single day.

 

GOES Sounder data can be used to created Derived Product Imagery (DPI) estimates of instability parameters (for example), and many are shown at this site. The GOES-13 Sounder has been offline for about a year after having suffered an anomaly back in November 2015, when the filter wheel became frozen, but the GOES-15 Sounder (and the GOES-14 Sounder) continue to operate. The animation below of GOES-15 Sounder Lifted Index shows values as low as -4ºC upstream of the Oregon Coast for many hours before the tornado; as such, it was a valuable situational awareness tool.

goes_sounder_dpi_14oct2016_1100_1700step

GOES-15 Sounder DPI Estimates of Lifted Index, 1100-1700 UTC on 14 October 2016 (Click to enlarge)

NOAA/CIMSS ProbSevere is a probabilistic estimate that a given thunderstorm will produce severe weather in the next 60 minutes. The animation below shows ProbSevere polygons overlain over radar from 1501 UTC (when the first ProbSevere polygon appeared around the radar cell that ultimately was tornadic) through 1521 UTC. Values from the ProbSevere output are below:

 

TIME PS CAPE SHR MESH GRW GLA FLSHRATE COMMENTS
1501 11% 1048 39.3 0.00 str str 0 fl/min Satellite from 1245/1241
1503 32% 1056 39.7 0.37 str str 0 fl/min Satellite from 1245/1241
1505 32% 1031 39.4 0.37 str str 0 fl/min Satellite from 1245/1241
1507 29% 1013 38.7 0.37 str str 3 fl/min Satellite from 1245/1241
1509 47% 974 37.9 0.62 str str 3 fl/min Satellite from 1245/1241
1511 47% 962 37.6 0.62 str str 3 fl/min Satellite from 1245/1241
1513 32% 745 33.1 0.52 str str 10 fl/min Satellite from 1245/1241
1515 34% 897 35.9 0.52 str str 1 fl/min Satellite from 1245/1241
1517 10% 887 35.7 0.52 N/A N/A 2 fl/min
1519 8% 762 33.6 0.54 N/A N/A 4 fl/min
1521 7% 737 33.1 0.49 N/A N/A 2 fl/min
realearthprobsevere_14october2016_1501_1521anim

NOAA/CIMSS ProbSevere output in RealEarth, 1501-1521 UTC on 14 October 2016 (Click to animate)

The Sounder also has a 9.6 µm “ozone absorption band”, and another example of GOES Sounder DPI is Total Column Ozone, shown below. Immediately evident is the sharp gradient in ozone (yellow to green color enhancement) located just north of the polar jet axis that was rounding the base of a large upper-level low (500 hPa analyses). The GOES-R ABI instrument also has a 9.6 µm band that is sensitive to ozone; however, there are no current plans to produce operationally a similar Total Column Ozone product.

 

GOES-15 Sounder Total Column Ozone DPI [click to animate]

GOES-15 Sounder Total Column Ozone DPI [click to animate]

Suomi NPP Day/Night Band Visible (0.70 µm) Image, 1057 UTC on 14 October 2016, Green Arrow points to Manzanita OR [click to enlarge]

Suomi NPP Day/Night Band Visible (0.70 µm) Image, 1057 UTC on 14 October 2016, Green Arrow points to Manzanita OR [click to enlarge]

Suomi NPP overflew the Pacific Northwest about 4 hours before the severe weather was observed at Manzanita. The Day/Night Visible Image above, courtesy of Jorel Torres at CIRA (Jorel also supplied the NUCAPS Sounding Imagery below), shows a well-developed storm offshore with thunderstorms off the West Coast of the United States (Click here for an image without the Green Arrow). Multiple overshooting tops can be discerned in the imagery.

NUCAPS Soundings are produced from the Cross-Track Infrared Sounder (CrIS, with 1300+ channels of information) and the Advanced Technology Microwave Sounder (ATMS, with 22 channels) that are present on Suomi NPP (in addition to the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument that provides the Day/Night band imagery). The image below shows the location of NUCAPS Soundings — the color coding of the points is such that Green points have passed Quality Control, whereas yellow points denote sounding for which the Infrared Sounding retrieval has failed to converge and Red points denote soundings for which both Infrared and Microwave sounding retrievals have failed to converge).

Suomi NPP Day/Night Band Visible Image, 1057 UTC on 14 October 2016, with NUCAPS Sounding Locations indicated.  The Green Circle shows the location of the Sounding below [click to enlarge]

Suomi NPP Day/Night Band Visible Image, 1057 UTC on 14 October 2016, with NUCAPS Sounding Locations indicated. The Green Circle shows the location of the Sounding below; Refer to the text for the Dot Color meaning [click to enlarge]

NUCAPS Soundings can give valuable information at times other than those associated with radiosonde launches (0000 and 1200 UTC, typically), and over a broad region. The point highlighted above, between the occluded storm and the coast, shows very steep mid-level lapse rates that suggest convective development is likely.

NUCAPS Sounding, location as shown by the Green Circle in the figure above. [click to enlarge]

NUCAPS Sounding, location as shown by the Green Circle in the figure above [click to enlarge]

The imagery below shows soundings a bit farther south, near convection that looks supercellular. The NUCAPS Soundings there suggest very steep mid-level lapse rates.

slide11