One of my favorite things to watch are upper-level +PV anomalies moving offshore the east coast & sparking surface cyclogenesis.

We had a classic example last night, where a pre-existing baroclinic zone (thanks to the Gulf Stream) rapidly evolved into a striking occluded low. pic.twitter.com/74ylYWj5z8

— Philippe Papin (@pppapin) February 4, 2019

The approach of an upper-tropospheric Potential Vorticity (PV) anomaly induced rapid cyclogenesis just off the US East Coast on 04 February 2019, with the surface low rapidly occluding (surface analyses). The eastward-propagating PV Anomaly was apparent on GOES-16 (GOES-East) Air Mass RGB images from the AOS site (below) as darker shades of orange — transitioning to shades of red as the tropopause descended to lower altitudes bringing more ozone-rich air from the stratosphere into the atmospheric column.

A sequence of Infrared Window images from Terra MODIS (11.0 µm) and NOAA-20/Suomi NPP VIIRS (11.45 µm) (below) showed the cyclone at various stages of development. The surface low passed over  the Cape Lookout, North Carolina buoy as it was intensifying, with winds gusting to 44 knots around 12 UTC (winds/pressure | peak wind gusts).

A similar sequence of Visible images from Terra MODIS (0.65 µm) and NOAA-20/Suomi NPP VIIRS (0.64 µm) (below) showed the cyclone during daylight hours.

===== 05 February Update =====

After the primary center of circulation began to weaken, a pair of residual lower-tropospheric vortices (surface analyses) was seen to persist on GOES-16 “Clean” Infrared Window (10.3 µm) images (above), rotating around each other in a binary interaction known as the Fujiwhara effect. The two vortices were also evident in NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 0620 UTC (below) — in spite of the lack of illumination from a New Moon, airglow alone was sufficient to provide an impressive “visible image at night” with the Day/Night Band. (note: the NOAA-20 VIIRS images are incorrectly labeled as Suomi NPP)

During the early morning hours, an undular bore was evident on GOES-16 “Red” Visible (0.64 µm) images (below), moving toward the westernmost vortex. As the bore began to move over warmer waters of the Gulf Stream, it slowly dissipated.

Although not particularly intense, this slow-moving midlatitude cyclone was able to draw an appreciable amount of moisture northward from the tropics/subtropics as shown by the MIMIC Total Precipitable Water product (below).

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The Korean Meteorological Administration (KMA) has released its first true-color image created with data from the AMI sensor on the GEOKOMPSAT-2A (GK2A) satellite that was launched in late 2018.   This first image from GK2A is experimental and preliminary, just like the initial images from Himawari-8,  -9, GOES-16 and GOES-17 were preliminary:  all newly-launched satellites go through a check-out period during which radiometric and geometric calibration work is ongoing.  That is what is happening with the  GK2A satellite now.  Despite the preliminary nature of the GK2A imagery, however, it can be paired with Himawari-8 imagery to create stereoscopic views of the Earth — in true color!   To view the image pair in three dimensions, cross your eyes until three circles appear, and focus on the circle in the middle;  it should appear then as a sphere.

(Image pair courtesy Bodo Zeschke, Australian Bureau of Meteorology ;  Himawari image courtesy JMA ; GK2A image courtesy KMA and Dr. Hyesook Park. GEOKOMPSAT-2A is also known as Chollian-2a)

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A meteorite landed near Viñales, Pinar del Río in western Cuba (about 58 miles or 93 km northeast of San Julian MUSJ) on 01 February 2019. GOES-16 (GOES-East) Split Cloud Top Phase (11.2 – 8.4 µm), Split Window (10.3 – 12.3 µm), Near-Infrared “Cirrus” (1.37 µm) and “Red” Visible (0.64 µm) images (above) revealed signatures of the airborne debris cloud as it drifted northeastward then eastward for about an hour after the impact (which occurred around 1817 UTC) — during that hour (from 1817 to 1917 UTC) the debris cloud traveled about 40 miles. A brief signature of another (lower-altitude) debris cloud moving southwestward was also seen immediately following impact, which was most apparent in the Split Window and Cirrus images.

The signatures in the Split Cloud Top Phase and Split Window imagery were due to the presence of mineral dust particles within the debris cloud — the emissivity properties of dust affects the sensed brightness temperatures differently for various infrared spectral bands. The Cirrus spectral band is useful for detecting the scattering of light by airborne particles such as ice crystals, volcanic ash, smoke or dust. The debris cloud was also casting a subtle shadow onto the surface, as seen in the Visible imagery.

Rawinsonde data from Key West, Florida (below) indicated that the northeastward to eastward drift of the debris cloud at a velocity of about 40 mph (35 knots) would have been occurring at altitudes of 4.9-5.5 km (pressures of 565-522 hPa).

The GOES-16 Geostationary Lightning Mapper also exhibited a signature around the time of the meteorite impact, as discussed here. Looking at GOES-16 Upper-level (6.2 µm), Mid-level (6.9 µm), Low-level (7.3 µm) and “Clean” Infrared Window (10.3 µm) images with plots of GLM Groups (below), a faint debris cloud signature could best be followed in the 7.3 µm imagery (AWIPS animation) after the 1817 UTC impact — but for a shorter time period than what was seen with the other GOES-16 examples shown above. While the Water Vapor band weighting functions for Key West had peaks at fairly low altitudes for 7.3 µm and 6.9 µm, the signature for any low/mid-tropospheric features would have been masked by absorption and re-radiation from moist layers within the upper troposphere.

* GOES-17 imagery shown here is preliminary and non-operational *

The bright signature of the bolide exploding as it entered the Earth’s atmosphere was also detected by the GLM instrument on GOES-17, although the viewing angle was much larger (with a zenith angle of 67 degrees, vs 30 degrees from GOES-16). The GLM Groups detected by both GOES-17 and GOES-16 were plotted with and without the native parallax correction (below).

The GOES-16 Lightning Mapper (GLM) may have caught the flash from the #Cuba meteorite this aftn. This 4-panel shows an extensive “flash” occurring in a mostly sunny scene. Day Cloud Phase RGB (UL), 10.35um Clean IR (UR), .64um VIS (LL), regional radar (LR) pic.twitter.com/atrtXjzOSf

— Steve Cobb (@imnotycobb) February 1, 2019

@NWSKeyWest radar may have detected the meteor that affected western Cuba earlier today. At 121 pm, a signature was detected near Viñales, Cuba, at a height of over 26,000 ft above ground level. #flwx #KeyWest #FloridaKeys #meteor pic.twitter.com/R2JIlVwpsS

— NWS Key West (@NWSKeyWest) February 1, 2019

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1-minute Mesoscale Domain Sector GOES-16 (GOES-East) Near-Infrared “Snow/Ice” (1.61 µm), Near-Infrared “Cloud Particle Size” (2.24 µm) and Shortwave Infrared (3.9 µm) images (above) displayed thermal signatures from a large fire at the Marcal Paper Mill in Elmwood Park, New Jersey during the evening hours of 30 January 2019. The fire reportedly began around 2215 UTC or 5:15 PM local time — and during the subsequent hours, strong winds with very cold temperatures (falling to the single digits above zero F) in the wake of a cold frontal passage hampered the firefighting efforts. Note on the plots of surface observations that smoke (K) was reported immediately downwind of the fire at Teterboro Airport (station identifier KTEB) from 02 to 05 UTC.

The nighttime thermal signatures seen on the near-infrared 1.61 µm and 2.24 µm images (brighter white pixels) result from the fact that those two ABI spectral bands are located close to the peak emitted radiance of very hot features such as volcanic eruptions or large fires (below).

The thermal signature of the fire became less distinct in GOES-16 imagery after about 06 UTC, but was still well-defined in higher-resolution VIIRS Shortwave Infrared (3.74 µm) imagery (below) from NOAA-20 (overpass data acquired at 0614 and 0754 UTC) and Suomi NPP (overpass data acquired at 0704 UTC).

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