GOES-16 Visible Imagery, above (Click to animate), shows shower/thundershower development over eastern Oklahoma moving into Arkansas. At the end of the animation, 1946 UTC, NUCAPS Sounding profiles from 1926 UTC are shown, and they’re shown below too.

The time 1946 UTC is about the earliest you could hope to have NUCAPS profiles in an AWIPS system — and only if you had access to a Direct Broadcast antenna. The more conventional method of data delivery, the SBN, means NUCAPS will be available about an hour after they are taken, so by 2036 UTC. The visible imagery at 2036 UTC is shown below.

At 2036 UTC, which time is about when in the forecast office the NUCAPS soundings would become available, would you expect the convection in western Arkansas to move southward, or eastward, based solely on Satellite imagery? How could you use NUCAPS profiles to gain confidence in this prediction? Visible imagery alone suggests a moisture boundary; the southern quarter of Arkansas shows markedly less cumulus cloudiness. The animation shows motion mostly to the east, with higher clouds moving more west-northwesterly. The GOES-16 Baseline Total Precipitable Water product, below, shows a maximum in TPW over central Arkansas, with values around 1.5″;  values are around 1.3″ in southern Arkansas, and around 1.2-1.3″ in northwest Arkansas.  A corridor of moisture is indicated.

Baseline Total Precipitable Water, above, part of a suite of products that emerge from Legacy Profiles, is heavily constrained by model fields, however;  the image above could simply show the GFS solution.  In contrast, NUCAPS observations are almost wholly independent of models.  What do NUCAPS profiles show? The animation below steps through vertical profiles east and south of the developing convection.

AWIPS will soon (planned for shortly after Labor Day at the time of this post) include horizontal fields of information derived from NUCAPS vertical profiles. The images below show values computed within the NSharp AWIPS software for a variety of fields: Total Precipitable Water, MU Lifted Index, MU CAPE, MU CINH. All fields suggest that convection more likely to build eastward than to expand southward.

Convection did not move southward; motion and development was to the east. The timing of NUCAPS profiles means that they give a good estimate of atmospheric thermodynamics in mid-afternoon, a key time for assessing convective development.

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The GOES-16 Visible (0.64 µm) image above shows a weak thunderstorm over southeastern Oklahoma surrounding an decaying outflow boundary.  (Click here to see an animation of the visible imagery). The convection did not look particularly robust, but it did produce lightning that was detected by the Geostationary Lightning Mapper (GLM), as shown below.

Lightning requires charge separation in a cloud; typically lightning occurs after the cloud top glaciates. During daytime, glaciation can be detected with ABI Band 5, at 1.61 µm, the so-called Snow/Ice band. The toggle below shows the visible, snow/ice band, and the Baseline Cloud Phase product. Glaciation is indicated.

This case is interesting because NOAA-20 overflew the convection, and soundings were produced around the convection, as shown below.

The animation below steps north-south through seven profiles that surround the weak convection. Note that a profile near the convection has thermodynamic parameters more favorable for convection than at the other profiles.  For example, NUCAPS profiles show the convection at the northern edge of a precipitable water gradient, and also in a local minimum of inhibition.    Although the convection has initiated here, the fields do suggest that NUCAPS can be used to monitor thermodynamics at small scales before initiation.

Horizontal gridded information derived from NUCAPS data will be in AWIPS shortly.  See this post from Emily Berndt at SPoRT!

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The above animation shows the ABI 3.9 µm band for regions of less solar illumination and the ABI 1.6 µm “snow/ice” band for regions more fully illuminated. Also shown is a readout of the GOES-16 cloud-type phase product for a point in eastern Texas. Note how the estimates range for this location from clear sky, liquid water, mixed phase and super-cooled droplets. This shows one example of how to use imagery in conjunction with derived products. These images where generated in AWIPS using a procedure.

Cloud-top phase can be found in RealEarth (search on ‘phase’), GEOCAT (direct link to cloud-top type), and the GOES-R cloud page. An archive of netCDF are held in NOAA’s CLASS.

There are many “Level 2” or derived products generated from the ABI radiances. These include, but are not limited to: cloud proprieties, atmospheric motion, fire, stability, sea and land surface temperatures. More information on these products can be found on the Algorithm Working Group web page, product quality web page or these links.

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Total Precipitable Water (TPW) calculated from rawinsonde data at both Anchorage and Fairbanks, Alaska were all-time record maximum values at 00 UTC on 14 August 2019.

The 0 UTC upper air sounding for Anchorage had a precipitable water value of 1.76″. This easily exceeds the previous all-time record of 1.67″ Aug 26, 1990. @AlaskaWx

— Brian Brettschneider (@Climatologist49) August 14, 2019

The 0 UTC upper air sounding for Fairbanks had a precipitable water value of 1.59″. This exceeds the previous all-time record of 1.57″ July 13, 1971. @AlaskaWx

— Brian Brettschneider (@Climatologist49) August 14, 2019

The microwave-based MIMIC TPW product (below) showed an atmospheric river of moisture moving northeastward toward Alaska during the 2 days leading up to the record-setting TPW values on the Anchorage and Fairbanks soundings. The global view suggested that some of this moisture may have originated from the northern periphery of the TPW reservoir associated with slow-moving Typhoon Krosa in the West Pacific Ocean, being transported eastward then northeastward by a series of frontal waves (surface analyses).

 

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