Possible Sting Jet Associated with strong storm in Europe

October 28th, 2013 |
Meteosat-10 6.2 µm WV channel images (click to play animation)

Meteosat-10 6.2 µm WV channel images (click to play animation)

Sting jets are wind maxima near the end of bent-back fronts in cases of strong cyclones. As noted earlier on this blog, they can acquire a characteristic look in water vapor imagery, vaguely reminiscent of a scorpion’s stinger. In addition, strongly sinking air around the jet, usually associated with both a tropopause fold and a maximum in ozone, is manifest as a warm (dry) patch in the water vapor (WV) imagery. In the animation above, the sting jet is apparent moving across northern Denmark into southern Sweden between 1500 and 1800 UTC. This is in association with the ‘St. Jude’ storm that killed more than a dozen across northern Europe (Reuters news story; Sky News story).

The strong sinking near a sting jet can transport momentum down to the surface. You should therefore expect to see strong surface wind gusts near the water vapor satellite signature, and that was the case on October 28, as shown below.

Hourly Meteosat-10 6.2 µm WV channel images and Observed Surface Wind Gusts (click to play animation)

Hourly Meteosat-10 6.2 µm WV channel images and Observed Surface Wind Gusts (click to play animation)

Suomi/NPP viewed this storm early in the day on 28 October. The toggle between the VIIRS Day/Night Band and the 11.45 µm IR data, below, shows a developing baroclinic leaf over the British Isles.

Toggle between VIIRS Day/Night Band and 11.45 µm IR imagery at 0220 UTC on 28 October (click to enlarge)

Toggle between VIIRS Day/Night Band and 11.45 µm IR imagery at 0220 UTC on 28 October (click to enlarge)

A comparison of Aqua MODIS 0.65 µm visible, 11.0 µm IR, and 6.7 µm water vapor channel images visualized using the SSEC Web map Server (below; courtesy of Russ Dengel and Kathy Strabala, SSEC) showed the storm at 12:14 UTC on 28 October. The warm/dry signature of strongly-subsiding middle to lower tropospheric air was particularly evident on the water vapor image (yellow to orange color enhancement) as it was beginning to move eastward over Denmark.

Aqua MODIS 0.65 µm visible, 11.0 µm IR, and 6.7 µm water vapor channel images

Aqua MODIS 0.65 µm visible, 11.0 µm IR, and 6.7 µm water vapor channel images

For additional satellite images of this event, see the EUMETSAT Image Library and the Wide World of SPoRT.

Possible Sting Jet in Upper Midwest

March 12th, 2012 |
GOES-13 6.5 µm water vapor channel images (click image to play animation)

GOES-13 6.5 µm water vapor channel images (click image to play animation)

The water vapor animation from GOES-East on March 12th shows a structure rotating through the upper-level trough, which structure looks very much like a so-called “Sting Jet”. (In the animation above, the sting jet structure crosses the Missouri/Kansas border south of Kansas City, propagates across northern Missouri and eastern Iowa before moving northward into Wisconsin). (A more obvious Sting Jet event is discussed here; A Monthly Weather Review article on Sting Jets is here).

RUC wind analyses show that the sting jet structure was associated with a wind maximum on the 315 Kelvin isentropic surface. This Loop shows the maximum moving from northeastern Missouri into Central Wisconsin between 1000 and 1400 UTC on March 12th. Stability in the lower troposphere on March 12th (as suggested by this sounding from the Quad Cities in Iowa/Illinois) was strong enough to inhibit vertical mixing of stronger upper-tropospheric air down towards the surface. The circulation around the jet was sufficient, however, to generate showers over the upper Midwest, as shown in this loop.

MODIS 6.5 µm water vapor channel image

MODIS 6.5 µm water vapor channel image

MODIS water vapor imagery, above, from 0841 UTC on 12 March shows the sting jet structure in north-central Missouri, and curving back to central Nebraska and central South Dakota.

GOES-13 0.63 µm visible image

GOES-13 0.63 µm visible image

(Added 13 March: SPC Storm Reports show a rare March tornado north of I-69 in lower Michigan. The visible imagery above, bracketing the observed time of the tornado (near the yellow box), shows a strong thunderstorm. By this time, the possible sting jet has rotated northward into western Ontario, so its influence on the environment in Michigan would be secondary. The sounding from DTX at 2300 UTC shows a favorable low-level wind profile.)

“Sting Jet” signature associated with a high wind event in Scotland

January 3rd, 2012 |
EUMETSAT Meteosat-9 7.35 µm water vapor channel images (click image to play animation)

EUMETSAT Meteosat-9 7.35 µm water vapor channel images (click image to play animation)

 

A rapidly intensifying mid-latitude cyclone (named “Cyclone Ulli” by the Europeans | surface analysis) was responsible for a high wind event as it moved over Scotland on 03 January 2012. A sequence of EUMETSAT Meteosat-9 7.35 µm water vapor channel images (above; click image to play animation) revealed two notable signatures: (1) the formation of a pronounced area of warm/dry water vapor brightness temperatures (bright yellow to orange color enhancement) over the open water north of Ireland, which indicated a strongly forced region of rapidly descending middle-tropospheric air, and (2) a classic “Sting Jet” signature (Monthly Weather Review | Wikipedia) which then moved eastward across Scotland. Just to the south of the sting jet signature, a wind gust of 78 knots (90 mph) was recorded at Glasgow at 08:20 UTC, followed by a wind gust of 70 knots (81 mph) at Edinburgh at 08:50 UTC.  There were additional reports of wind gusts in excess of 87 knots (100 mph) at non-METAR sites in Scotland.

The Sting Jet signature can also be seen in EUMETSAT Meteosat-9 10.8 µm IR images (Animated GIF | QuickTime movie) and EUMETSAT Meteosat-9 0.635 µm visible channel images (Animated GIF | QuickTime movie).

A comparison of 1-km resolution NOAA-19 0.63 µm visible channel and 10.8 µm IR channel images at 12:54 UTC (below) showed the structure of the cyclone as it was centered over the North Sea between the British Isles and Norway.

 

NOAA-19 0.63 µm visible channel image + NOAA-19 10.8 µm IR channel image

NOAA-19 0.63 µm visible channel image + NOAA-19 10.8 µm IR channel image

Additional images of this Sting Jet event are available on the EUMETSAT and NASA Wide World of SPoRT sites.

Small Eddy and coastal jet off the coast of Northern California

May 4th, 2017 |

GOES-16 Visible (0.64 µm) from 1245 through 2200 UTC on 4 May 2017 (Click to play mp4 animation)

GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing.

One of the two GOES-16 Mesoscale Sectors was moved from its default position over the eastern United States and placed over the west coast of the United States on 4 May 2017. This allowed 1-minute imagery of a small-scale coastal eddy between Cape Mendocino and Pt. St. George near Crescent City, above, and an associated coastal jet. (Click here to play 300-meg Animated Gif; alternatively, this animation shows the eddy from 1600-1900 UTC as displayed in AWIPS (courtesy Dan Miller, WFO DLH))

A zoomed-in Visible animation of the coastal eddy is shown below; NWS Eureka described it as “one of the best examples of these coastal eddies seen in quite a while”.

GOES-16 Visible (0.64 µm) images, with hourly surface reports plotted in yellow (Click to animate)

GOES-16 Visible (0.64 µm) images, with hourly surface reports plotted in yellow (Click to animate)

GOES-16 Visible 0.64 µm imagery is able to capture not only the eddy, but also the northerly low-level jet that develops off the coast of Cape Mendocino, swiftly moving clouds southward around that feature. A small eddy also develops south of Cape Mendocino. Note also the abundance of cirrus clouds flowing northward along the coast.

The dimensions of this eddy are approximately 70 km in the along-shore direction and 55 km perpendicular to the shore, yet GOES-16 is able to capture and resolve many small-scale cloud bands. The small cloud band streaming south around Cape Mendocino, for example, is only about 6 km wide and is well-resolved; if GOES-16 becomes GOES-East at 75 W Longitude, this is the type of resolution that can be expected in Salt Lake City.

It should be noted that none of the models (including the hourly RTMA, below) resolved this eddy feature.

Suomi NPP VIIRS Visible (0.64 µm) image, with RTMA surface winds {Click to enlarge)

Suomi NPP VIIRS Visible (0.64 µm) image, with RTMA surface winds {Click to enlarge)

Thanks to Dan Miller, Science and Operations Officer (SOO) in Duluth for calling this awesome feature to our attention!