CMORPH estimates of hourly (and daily) rainfall with Sally

September 16th, 2020 |

CMORPH hourly estimates of precipitation over Mississippi and surrounding states, 1300-2200 UTC 16 September 2020 (Click to enlarge)

Hurricane Sally weakened to a Tropical Storm at 1800 UTC on 16 September. Sally is a prodigious rainfall producer. CMORPH (CPC Morphing Technique) Precipitation estimates (blogged about earlier) are available at this Real Earth website. Hourly estimates from 1300 through 2200 UTC are shown above.  Many locations over southern Mississippi show hourly multi-inch accumulations for much of the day.

Daily precipitation for the 24 hours ending at 00 UTC on 17 September is shown below.  A large area of Mississippi shows values between exceeding 100-150 mm.  Click here to see a 24-h precipitation total image for the period ending 1200 UTC on 17 September (from this website) A series of daily images of 24-hour precipitation (at bottom) shows the evolution of the diagnosed precipitation from 09-16 September.

Daily CMORPH Precipitation Accumulation, valid 0000 UTC on 17 September 2020 (Click to enlarge)

Daily CMORPH estimates of precipitation, 09-16 September 2020 (Click to enlarge)

CMORPH Precipitation Data available

September 3rd, 2020 |

Daily CMORPH maps of of daily precipitation, 26 August – 2 September 2020 (Click to enlarge)

The Climate Prediction Center (CPC) Morphing (CMORPH) technique produces global estimates of hourly precipitation and those data are available in real time at this website. (Other JPSS/ABI-related flood products are available there as well). CMORPH uses microwave data from Polar Orbiters to estimate rainfall. Infrared information is related to those microwave data estimates, and those infrared data (from ABI, AHI, etc) are used to estimate precipitation during times when microwave observations are not present. This morphing technique is thus different from other morphing techniques for Total Precipitable Water (TPW) such as MIMIC that use model data to move quasi-conserved moisture fields to observational data voids. (Training on MIMIC TPW fields).

Hourly and Daily precipitation totals are available at the website. The animation above shows annual precipitation over the course of 6 days. Daily precipitation on 27 August, for example (link), shows the heavy rain accompanying land-falling Hurricane Laura. In the animation, the rains with that system move north to the mid-Mississippi River before being shunted eastward.

Hourly Precipitation, shown below from 12-15 UTC on 3 September 2020, allows for enhanced situational awareness with respect to heavy (or light) rains.

CMORPH Hourly Precipitation from 1200 – 1559 UTC on 3 September 2020 (Click to enlarge)

Heavy rainfall across Interior Alaska

August 2nd, 2020 |

Topography + GOES-17 "Clean" Infrared Window (10.35 µm) images [click to play animation | MP4]

Topography + GOES-17 “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

An animation of Topography + GOES-17 (GOES-West) “Clean” Infrared Window (10.35 µm) images (above) showed a southward-moving band of clouds responsible for producing heavy rainfall across portions of Interior Alaska on 02 August 2020. Cloud-top infrared brightness temperatures were as cold as -58ºC (brighter shades of yellow).

GOES-17 “Red” Visible (0.64 µm) images are shown below.

GOES-17 "Red" Visible (0.64 µm) images [click to play animation | MP4]

GOES-17 “Red” Visible (0.64 µm) images [click to play animation | MP4]

Blended Total Precipitable Water (TPW) and Percent of Normal TPW images during the 01-02 August time period (below) portrayed TPW values as high as 1.5 inches just north of Lake Minchumina — which was >190% of the normal value for this location and time of year.

Blended TPW and Percent of Normal TPW images [click to play animation | MP4]

Blended TPW and Percent of Normal TPW images [click to play animation | MP4]

A sequence of VIIRS Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP as viewed using RealEarth (below) revealed cloud-top infrared brightness in the -60 to -65ºC range (darker shades of red) within this cloud band.

VIIRS Infrared Window (11.45 ) images from NOAA-20 and Suomi NPP [click to enlarge]

VIIRS Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP [click to enlarge]


Severe thunderstorms across the Upper Midwest

July 17th, 2020 |

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images, with and without an overlay of GLM Flash Extent Density [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (with and without an overlay of GLM Flash Extent Density) [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images — with and without an overlay of GLM Flash Extent Density (above) — showed the development of a large Mesoscale Convective System (MCS) that developed over North Dakota and began moving eastward into Minnesota on 17 July 2020 (surface analyses). These thunderstorms produced a variety of severe weather, and heavy rainfall with up to 6 inches in North Dakota and 4 inches in Minnesota.

GOES-16 “Red” Visible (0.64 µm) images, with SPC Storm Reports plotted in red [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm) images, with time-matched SPC Storm Reports plotted in red [click to play animation | MP4]

1-minute GOES-16 Visible images (above) and Infrared images (below) include time-matched plots of SPC Storm Reports — of particular note was the wind gust of 101 mph (GOES-16 Visible / Infrared images) that occurred at a RAWS site in northeastern North Dakota around 2045 UTC, in the vicinity of a brief tornado. As the MCS continued to expand southward and eastward during the subsequent nighttime hours, it eventually produced damaging winds across northeastern South Dakota, much of Minnesota and northwestern Wisconsin.

GOES-16 “Clean” Infrared Window (10.35 µm) images, with time-matched SPC Storm Reports plotted in cyan [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images, with time-matched SPC Storm Reports plotted in cyan [click to play animation | MP4]

Animations of CIMSS Clear Sky Convective Available Potential Energy (CAPE), Lifted Index (LI) and Total Precipitable Water (TPW) products (below), from this site, showed the rapid destabilization and moisture increase of the air mass south and southeast of the developing MCS; this corridor of moist and unstable air was feeding northward, helping to sustain MCS growth and propagation.

CIMSS Clear Sky CAPE images [click to play animation]

CIMSS Clear Sky CAPE images [click to play animation]

CIMSS Clear Sky LI images [click to play animation]

CIMSS Clear Sky LI images [click to play animation]

CIMSS Clear Sky TPW images [click to play animation]

CIMSS Clear Sky TPW images [click to play animation]

These severe thunderstorms with tall cloud tops provided a good demonstration of the parallax shift inherent in GOES imagery at higher latitudes. Time-matched comparisons of Infrared images from NOAA-20 at 1933 UTC and Suomi NPP at 2023 UTC with the corresponding images from GOES-16 (below) showed that the GOES images were shifted northwest of the more accurate NOAA-20/Suomi NPP images.  The superior 375-meter spatial resolution of the VIIRS instrument allowed subtle cloud-top gravity waves to be seen — and the VIIRS cloud-top infrared brightness temperatures were about 10ºC colder than those sensed by the ABI instrument. The 1933 UTC images were about 15 minutes prior to the tornado and 101-mph wind gust at Churches Ferry (located about 20 miles northwest of Devils Lake KDVL).

Infrared Window images from NOAA-20 (11.45 µm) and GOES-16 (10.35 µm) at 1933 UTC [click to enlarge]

Infrared Window images from NOAA-20 (11.45 µm) and GOES-16 (10.35 µm) at 1933 UTC [click to enlarge]

Infrared Window images from Suomi NPP (11.45 µm) and GOES-16 (10.35 µm) at 2023 UTC [click to enlarge]

Infrared Window images from Suomi NPP (11.45 µm) and GOES-16 (10.35 µm) at 2023 UTC [click to enlarge]

An image showing parallax correction vectors and distance for a 50,00 ft (15.2 km) cloud top feature at various points within the GOES-16 CONUS domain (below) is from this site — and indicated a southeastward correction of about 28-30 km (or 17-19 miles) over northern North Dakota. This is in good agreement with what was seen in the 2 VIIRS/ABI infrared image comparisons shown above.

Parallax correction vectors (green) and distance (in km, red) for various points within the GOES-16 CONUS domain [click to enlarge]

Parallax correction vectors (green) and distance (in km, red) for a 50,00 ft (15.2 km) cloud top feature at various points within the GOES-16 CONUS domain [click to enlarge]