Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images at 0801 UTC or 3:01 am local time (above) showed cloud-top infrared brightness temperatures were as cold as -83º C (violet color enhancement), along with a number of bright streaks on the Day/Night Band image due to cloud illumination by intense lightning activity (there were around 5000 cloud-to-ground lightning strikes associated with this MCS). On the infrared image, note the presence of cloud-top gravity waves propagating outward away from the core of overshooting tops.
This MCS produced heavy rainfall, with as much as 3.44 inches reported near Lomax (NWS Midland TX rainfall map | PNS). An animation of radar reflectivity (below, courtesy of Brian Curran, NWS Midland) showed the strong convective cells moving southward (before the Midland radar was struck by lightning and temporarily rendered out of service).During the subsequent daytime hours, GOES-13 Visible (0.63 µm) images (below) revealed the presence of a large and well-defined Mesoscale Convective Vortex (MCV) as the cirrus canopy from the decaying MCS eroded. A fantastic explanation of this MCV was included in the afternoon forecast discussion from NWS Dallas/Fort Worth. New thunderstorms were seen to develop over North Texas during the late afternoon and early evening hours as the MCV approached — there were isolated reports of hail and damaging winds with this new convection (SPC storm reports). Initiation of this new convection may have also been aided by convergence of the MCV with a convective outflow boundary moving southward from Oklahoma. A sequence of Visible images from POES AVHRR (0.86 µm), Terra MODIS (0.65 µm), and Suomi NPP VIIRS (0.64 µm) (below) showed snapshots of the MCV at various times during the day.
A higher resolution view was provided by POES AVHRR Visible (0.86 µm) and Infrared (12.0 µm) imagery at 2332 UTC (below) — details of the overshooting top, anvil plume, and enhanced-V signature showed up very well in the 1-km resolution images.
Although the storm produced a funnel cloud (prompting the issuance of Canada’s first tornado warning of 2016):
— The Weather Network (@weathernetwork) June 10, 2016
no tornado was confirmed. There were reports of golfball-size hail at Lauder (located just northeast of Melita, Manitoba CWEI) and wind gusts to 96 km/hour or 56 knots at Killarney (located east of Melita).
POES AVHRR CLAVR-x Cloud Top Temperature and Cloud Top Height products (below) indicated minimum values of -76º C and maximum values of 13 km, respectively.A surface frontal analysis (below) showed that the thunderstorms formed in the broad warm sector of a large occluded low pressure system centered in Saskatchewan, with a secondary low moving eastward across northern North Dakota — the RTMA surface wind field depicted the broad southerly flow of warm, moist air into Manitoba ahead of the storms (in addition to an interesting area of strong southwesterly flow into the rear flank of the storm).
===== 01 June Update =====The remnant circulation of Bonnie moved very slowly northeastward during the 30 May – 01 June period, as seen in GOES-13 Visible (0.63 µm) images covering each of those 3 days (above; also available as a large 95 Mbyte animated GIF). The periodic formation of deep convective clusters continued to produce heavy rainfall over parts of far eastern North and South Carolina.
On the morning of 01 June, an overpass of the Metop-B ASCAT instrument sampled the flow around the low-level circulation center (LLCC) off the coast of North Carolina; several hours later, Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images provided a high-resolution view of the system at 1755 UTC (below). Cloud-top IR brightness temperatures were as cold as -78º C within the small convective cluster located just north of the LLCC.