Today marks the 64th anniversary of the first image from the meteorological satellite TIROS-1, which was available on 01 April 1960. While TIROS-1 was only operational for 78 days, it provided a number of images of the Earth and cloud systems (including the first image of a tropical cyclone, over the South Pacific Ocean on 10 April 1960).

However, this information suggests that the TIROS-1 image shown above — which has gained notoriety as being the first — was actually taken at 1608 UTC on 02 April 1960! Apparently the true “first image” from TIROS-1 was taken at 1331 UTC on 01 April 1960, which is shown below (courtesy of Rick Kohrs, SSEC).

View only this post Read Less

United Airlines Flight 85 (UAL85) encountered severe turbulence as it was on approach to landing at Newark Liberty International Airport (KEWR) — which injured 22 passengers, with 7 of those being transported to a hospital (media report 1 | media report 2) late in the day on 29 March 2024. Gusty NW winds may have contributed to the turbulence (which likely occurred around 2138 UTC, according to flight data from FlightAware — note the rapid rate of ascent beginning at that time); the peak wind gust at KEWR was 48 knots or 55 mph at 2039 UTC. After UAL85 aborted its landing at KEWR, it diverted north to New York Stewart International Airport (KSWF), landing at 2208 UTC (above).

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) Low-level Water Vapor (7.3 µm) images (below) depicted widespread mountain waves across southeastern New York and northern New Jersey during that time. These mountain waves could also have played a role in creating boundary layer turbulence. The Pilot Report (PIREP) for this UAL85 incident did not appear in the real-time AWIPS data, probably due to time restraints imposed upon the flight crew to get the aircraft safely diverted as quickly as possible.

In a faster animation of GOES-16 Water Vapor images without plots of surface reports (below), note that the mountain wave structure across northern New Jersey (including near KEWR) becomes slightly deformed, and even begins to move westward a few miles.

A toggle between GOES-16 Water Vapor imagery and Topography (below) indicated that these mountain waves were forming downwind of the Catskills in New York and the Poconos in Pennsylvania.

Plots of rawinsonde data from Albany NY and Upton NY (below) both showed adiabatic or near-adiabatic lapse rates below the 800-850 hPa pressure level — which aided in the downward transport of momentum (stronger winds) aloft to the surface earlier in the day.

View only this post Read Less

NOAA-20’s early morning orbit and clear skies allowed a distinct view of Sea Surface Temperatures over the Gulf of Mexico and the East Coast on 29 March 2024, as shown above (The data, derived from the CIMSS Direct Broadcast Antenna) are available via an LDM feed from CIMSS). The Loop Current in the Gulf of Mexico (with surface temperatures from 80-81^oF) is obvious, as is the Gulf Stream along the East Coast.

How did the VIIRS Sea Surface Temperature values compare with co-located Fixed Buoy values? In the 3 examples below, the agreement was quite good — within 1ºF. Buoy SST values appear in the lower right corner of their station model plots.

Two aspects (at least!) of this imagery bear mention. The Mississippi River delta (enlarged, below) is a source of cool water flowing into the Gulf. The cyan values are temperatures from 58-61^oF vs low 70s ^oF (in yellow) just offshore.

There is a very tight thermal gradient northeast of the Outer Banks of North Carolina! The magenta color shows temperatures in the upper 40s oF vs upper 70s (in orange) less than 20 miles away!

---

How do the VIIRS SSTs compare to GOES-16’s? The toggle below over the northern Gulf shows differences related to cloud detection over the cooler waters of the Mississippi River delta, and along the edge of the warmer waters offshore: NOAA-20 has a more complete picture.

The NOAA-20 imagery is also more complete near the Outer Banks as shown in the toggle below.

View only this post Read Less

LightningCast is a product within the ProbSevere portfolio that uses 4 ABI (or AHI) channels to estimate the likelihood of a GLM observation within the next 60 minutes. For the past couple years, this product has been used experimentally over Guam (using Himawari-9 data), even though the product was trained using GOES-16 data. ABI and AHI channels are similar enough that a useful signal can occur. The animation shows the Himawari-9 Day Cloud Phase RGB (using Band 3, 5 and 13; those 3 bands plus Band 15 are used by the LightningCast algorithm to create probabilities) over northwestern Australia, showing both Darwin and the Tiwi Islands. The contours of the right show the likelihood of a lightning observation within the next 60 minutes. Note how some of the cirrus clouds (yellow in the RGB) have high probabilities whereas others — correctly — have low (usually in regions where the thick cirrus is dissipating). Careful inspection of the animations show that probabilities increase before deep convection is present. That is perhaps more easily seen in the toggle below of imagery at 0250 and 0350 UTC; at 0250 UTC probabilities are elevated in/around Darwin Australia (circled in cyan) with only a few glaciated clouds over land (i.e., clouds that are yellow in the RGB). At 0350 UTC, in contrast, well-developed convection is apparent (with continuing high probabilities) in the same region; lightning is probably occurring.

These LightningCast probability fields were computed using CSPP-Geo software; that software is nearing a beta release.

View only this post Read Less