Moisture streaming in from the Gulf of Mexico in combination with burn scars lead to to flash flooding across New Mexico on Wednesday, June 19. From NWS Albuquerque in the PM of 06/19: “At 318 PM MDT, Doppler radar indicated thunderstorms producing heavy rain over the McBride Burn Scar. Between 1 and 2 inches of rain have fallen. Additional rainfall amounts of 0.5 to 1.5 inches are possible in the warned area. Flash flooding is ongoing or expected to begin shortly.”, and shortly thereafter: “…FLASH FLOOD EMERGENCY FOR RIO HONDO…Some locations that will experience flash flooding include Ruidoso, Ruidoso Downs, San Patricio, Hondo, Tinnie, Glencoe, Sunset and Hollywood.” NWS Weather Prediction Center (WPC) forecasters were concerned about the burn scars near Ruidoso, NM, on 18 June 2024, identifying the burn scars using GOES 3.9um (Shortwave Infrared, Band 7) imagery. In the GOES Band 7 imagery, the lighter colored (warmer) spots in the red circled region represent burn scars near Ruidoso, NM, on 18 June 2024.
The Day Land Cloud Fire RGB can make it even easier to detect burn scars. The GOES-East Day Land Cloud Fire RGB creates natural color surfaces, and the burn scar can clearly be spotted in the red circled region by its dark brownish red color, on 18 June 2024.
On 19 June 2024, GOES-East Airmass RGB imagery from ~1700 UTC to ~2300 UTC showed a dry airmass (dark reds) being replaced with an airmass with more moisture and low to mid-level clouds (light olive green color) as a boundary pushed west before convection fired (bright white color). Also note a deep tropical airmass in the lower right associated with then Tropical Storm Alberto.
NWS WPC Forecaster Jacob Asherman used the Day Cloud Phase Distinction RGB, as well as the experimental LightningCast product, to monitor glaciation in the clouds and assess convective initation ahead of issuing a Mesoscale Precipitation Discussion in the PM of 06/19. In the GOES-East Day Cloud Phase Distinction RGB imagery, clouds can be seen changing from light blue to greens, yellows, and red-orange as convective initiation occurs and storms mature over central NM from ~1700 UTC to ~2300 UTC 19 June 2024.
Forecaster Jacob Asherman noted that LightningCast helped detect convective initation in NM “2-3 hours earlier than all of the CAMS” (convection-allowing models), starting around 1800 UTC 19 June 2024. Jacob had overlaid LightningCast over the Day Cloud Phase Distinction RGB in AWIPS, a great combination as LightningCast uses the Day Cloud Phase Distinction RGB bands as inputs to predict the probability that the GLM will observe lightning in the next hour. LightningCast just became available in WPC AWIPS this month. Due to the short archive time of satellite imagery and products in AWIPS, I grabbed imagery from SSEC RealEarth. LightningCast was overlaid on the VIIRS Imagery Band 02 (0.865 um) to have a visible background since the archive for GOES imagery was also unavailable.
The MPD issued at 2009 UTC 19 June 2024 noted: “Recent GOES Day Cloud Phase RGB and GLM data suggest convective initiation is underway across portions of South-Central New Mexico, with increasing glaciation and lightning activity noted along the Sandia Manzano and Sacramento Mountains”. GOES-East GLM indeed showed lightning by ~1930 UTC with storms expanding thereafter in the animation from ~1700 UTC to ~2300 UTC 19 June 2024.
MRMS Merged Base Reflectivity Quality Controlled (QC) data from ~1700 UTC to ~2300 UTC 19 June 2024 showed the storms that fired over NM before becoming nearly stationary, causing flash flooding.
A local storm report near Ruidoso, NM, around ~2300 UTC noted: “Swiftwater rescues out the Rio Ruidoso. Number of people rescued unknown. Emergency manager requested Flash Flood Emergency for river and highway 70 down to Two Rivers Dam.”
Chris Smith, CISESS GOES-R Satellite Liaison for NWS WPC/OPC