18Z NUCAPS (Op vs Experiment), Viewing, and Latency

The 18z SNPP NUCAPS Soundings

As noted from a previous post, the RGB Simple Water Vapor image depicted some increase in water vapor in the mid/upper levels. The 18z pass may have passed a bit too early to capture this moistening, but it served as a good opportunity to compare NUCAPS with the 12z Denver ROAB.  

Overall comparisons of moisture using mixing ratio values were nearly identical when inspecting mandatory pressure levels with the 12z sounding.

  

SNPP NUCAPS Operational

 

The experimental soundings with the adjusted surface values however may have moistened the low levels too much again when assuming a perfectly mixed layer.  This more than doubled the mixing ratio at 700mb from about 4 g/kg to 9 g/kg which inflated the CAPE by about +600 j/kg. 

SNPP NUCAPS Experimental

Some final thoughts on the use of NUCAPS during the Testbed:

1.  Overall use: I find the availability of NUCAPS soundings very beneficial in the field particularly for offices in the western U.S. which are often subject to data voids. Although I think much work can be done to increase its utility in field (better temporal resolution, tailored fields of interest for the a forecast, better gridded data viewing...little ragged at times, and training for forecast operations).

2.  Temporal Resolution: It would very useful in the field to be able to get multiple passes during the day to be able to monitor evolution of fields of interest. Use of MetOpA to supplement temporal resolution is useful and would be good to have these soundings on future polar orbiters. Ideally an hourly availability would be quite useful and even game changing for potential research items such as:

• Monitoring mixed layer depth evolution which are quite important in regards to fire weather/explosive wildfire growth (Haines Index) and smoke dispersion. 
• Monitoring inversion (stable layers) which are critical for downslope wind storms, air quality, convective suppression or cap breaking. 
• Stability evolution (assuming better temporal resolution) for aviation, particularly glider pilots. 

3. Experimental NUCAPS: I do see the high utility in having both the operational NUCAPS soundings available alongside the experimental surface obs adjusted values. Even though I think the correction may be oversimplified in assuming a perfectly well mixed layer of moisture, it is still useful to see.

4. Data visualization: I think both soundings and gridded data are necessary to get the full potential of the NUCAPS data.

• The soundings are useful in analyzing all the traditional features of interests that we use with upper air. (Stability, moisture layers, lapse rates, etc). 

• The gridded NUCAPS I found were a little clunky at first but currently there are no easy menu options to view data and would have to build everything using the volume and product browsers. This would need to be streamlined greatly.  The high vertical resolution is also valuable in that it allows you to evaluate plan views of temperature, moisture, possibly even heights of temperature surfaces (example freezing levels, -20, inversion heights) and whatever pressure level is available.  This evaluation of gradients would be easy to do this way.

5. Data Latency: Simply, the quicker we can get the data the better. Particularity getting both the operational and experimental profiles at near the same time would be ideal to be to do analysis on both at the same time.

Forecaster: Tahoe