The Storm Prediction Center issued an Extreme Fire Weather Outlook (note that those conditions are #6 on the Priority List for Mesoscale Sectors!) for portions of southern California on 6 November 2024, and the forecast office in Los Angeles issued both High Wind Warnings — for strong Santa Ana winds — and a Red Flag Warning, as shown here, noting that this was a Particularly Dangerous Situation. The NGFS dashboard shown below includes the alert readout for this fire several hours after its initiation. The fire was detected by three different scannings: the GOES-16 CONUS scan, the GOES-18 PACUS scan, and the GOES-18 Mesoscale Sector 1 scan. Which scan strategy saw it first? It should be no surprise that the 1-minute cadence of the Mesoscale Sector first saw the fire. The first 15 minutes of the detections are shown above.

NGFS imagery below tracks the early development of the detections, at 1649, 1650, 1651, 1655 and 1700 UTC. NGFS Microphysics RGB is on the left, Fire Temperature RGB is on the right. The signal is initially apparent only in the NGFS Microphysics. It takes several minutes for a credible signal to appear in the Fire Temperature RGB — at 1655 UTC. These 5 images also show how mesoscale scanning (every minute) captures the rapid changes that occur.

Three different GOES-R sectors were scanning this region; the GOES-18 Mesosector initially detected the fire at 1650 UTC. The toggle below shows the 5-minute scans from the GOES-16 CONUS sector (left) and the GOES-18 PACUS Sector at 1649, 1651 and 1656 UTC. The different colors in the NGFS Microphysics RGB imagery between the two satellites occur because of the different distances from the GOES-16 and GOES-18 sub-satellite points. A Fire pixel is detected by GOES-18 at 1651 UTC, one minute later than the mesosector detection above. A definitive pixel is not detected by GOES-16 until 1656 UTC. Make sure you are using the correct satellite and the correct scanning strategy (Call a meso!) if you are in a situation where every minute matters.

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Santa Ana winds (surface analysis shown below) means that this fire grew quickly.

The toggle below compares the NGFS microphysics RGB and the Fire Temperature RGB at 1850 UTC, about 2 hours after the fire’s start. Significant growth in the fire area is apparent, and it has become very intense.

The RealEarth NGFS instance for the Mountain Fire allows a user to add other fields to the display in addition to satellite imagery and fire detections. GOES-18 Fire Temperature RGB with Building Counts is shown below. This active fire is just upwind of a significant amount of development!

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The animation below from the CSPP Geosphere site shows the effect of the strong winds: the plume from this fire rapidly moves offshore. There is also a dust plume in the southern part of the the animation, also suggestive of strong winds. Indeed, the winds are strong enough to ground fixed-wing aircraft that might otherwise be used to fight this fire!

The animation for the same time of shortwave infrared data, below, shows the rapid development and expansion of the hotspot.

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1-minute GOES-18 Visible images with an overlay of the Fire Mask derived product (above) displayed the rapid increase in areal coverage and spread of the Mountain Fire’s thermal signature — the initial Fire Mask detection occurred at 1653 UTC. At 1945 UTC, the dense smoke plume reduced surface visibility to 1 mile at Oxnard; this smoke plume continued to drift across parts of the offshore Channel Islands National Park throughout the day. During that time period, peak wind gusts were 56 knots (64 mph) at Camarillo Airport, 55 knots (63 mph) at Point Mugu Naval Air Station and 50 knots (57 mph) at Oxnard (when blowing dust was being reported). The thermal signature indicated that the head of the wildfire quickly approached the Camarillo area and Highway 101.

30-second GOES-19 (*Preliminary/Non-operational*) Shortwave Infrared images (below) also showed the rapid southwestward run of the Mountain Fire toward Camarillo (KCMA) and Highway 101, driven by the strong northeast Santa Ana winds. (Thanks to Bill Line, NOAA/NESDIS for requesting the overlapping GOES-19 Mesoscale Sectors!)

CIMSS True-Color Imagery, below (courtesy Tim Schmit, NOAA/STAR) also from GOES-19 and at a 30-second cadence (and also Preliminary and Non-Operational), as above, shows the development of the smoke plume during the day on the 6th, and shows the dust plume to the south.

Tim Schmit also supplied (Preliminary, Non-Operational) 30-second GOES-19 True Color Imagery shown below.

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More information on this fire is available at the Watch Duty website, shown below. Active evacuations are occurring as of 2100 UTC on 6 November 2024. The first entry for this fire is at 1655 UTC — “Possible vegetation fire reported at Balcom Canyon, with smoke visible on Alert California cameras.”

Webcam imagery of this fire is available here. A Satellite Liaison Blog Post by Bill Line on this event is here.

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The area of convection that has been percolating within the Caribbean has acquired sufficient organization and speed to be named Tropical Storm Rafael (at 2100 UTC on 4 November, near the end of the animation, above, created at the CSPP Geosphere site). The storm is approaching the island of Jamaica where Tropical Storm Warnings are in effect.

1-minute GOES-16 Visible and Infrared images (above) showed Rafael as it intensified from a Tropical Depression to a Tropical Storm by 2100 UTC. Near the center of Rafael’s circulation there were periodic convective bursts (exhibiting cloud-top infrared brightness temperatures as cold as -88ºC), but there was very little GLM-observed lightning activity near the core of the tropical cyclone. Rafael was located just to the west of Buoy 42058, where the Sea Surface Temperature was 86ºF.

Rafael is currently in a region of warm sea-surface temperatures and low shear (imagery below is taken from SSEC/CIMSS’s tropical weather website), and slow strengthening is forecast as it moves between Jamaica and the Caymans en route to western Cuba.

The area of rich moisture that is supporting Rafael’s convection has been over the western Caribbean since late October. The animation for November of TPW from the MIMIC site (online archive) is shown below. Note, however, the relative dryness over the Gulf of Mexico, where Rafael is forecast to be by week’s end. The storm would have to overcome a significant amount of dryness to remain intense.

Advanced Clear-Sky Processor for Ocean (ACSPO) Sea Surface Temperatures from VIIRS, below, shown with I05 (11.45 µm) data (NOAA-20 data were downloaded at the CIMSS Direct Broadcast site and processed with CSPP software). Note the lack of convection over the Gulf of Mexico, and the water temperatures. Red in the SST enhancement below is approximately 80^oF. Shelf waters are relatively cool.

GOES-East airmass RGB imagery, below, shows Rafael developing within a moist airmass — that is, a green region within the RGB. As it moves northwestward, however, the environment becomes less favorable; this is indicated by regions with more orange. (Here is a Quick Guide on airmass RGB; here is another one)

===== Late 5 November Update =====

1-minute GOES-16 Infrared images (above) showed Tropical Storm Rafael as it intensified to a Category 1 Hurricane near the Cayman Islands at 0020 UTC on 06 November. Cloud-top infrared brightness temperatures associated with convective bursts near the center of Rafael were as cold as -91ºC; however, no GLM-detected lightning activity was seen with this convection during that 9-hour period.

A GOES-16 Infrared/Water Vapor Difference product (below) included an overlay of contours and streamlines of deep-layer wind shear. Rafael continued to remain in an environment of favorably low shear — and tropical overshooting tops that were likely penetrating the local tropopause were highlighted by increasingly negative values of the Infrared/Water Vapor Difference product (reference).

More information on Rafael is available from the National Hurricane Center. Interests in the northwest Caribbean and in the Gulf of Mexico should monitor the progress of this storm.

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Overlapping 1-minute Mesoscale Domain Sectors provided 30-second interval GOES-19 (Preliminary/Non-operational) “Red” Visible (0.64 µm) images (above) — which showed thunderstorms that produced hail to 1.75″ in diameter, wind gusts to 94 mph and several tornadoes (SPC Storm Reports) across parts of North Texas. eastern Oklahoma and far northwestern Arkansas on 04 November 2024.

The corresponding 30-second GOES-19 “Clean” Infrared Window (10.3 µm) images are shown below. The coldest cloud-top infrared brightness temperatures associated with some these thunderstorms were -70 to -75ºC.

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NUCAPS estimates of temperature and dewpoint give swaths of information over the Arctic — a region where conventional observations are uncommon and widely spaced. The toggle above shows a disorganized low pressure system over central Alaska — light snow is widespread as shown by the surface observations, below (and in the toggle above).

The toggle above includes swaths of temperature and of relative humidity (derived from all NUCAPS profiles at that time) that are shown individually below. The color bar for 850-mb temperature has been modified so that temperatures of 0^oC and -10^oC are contoured in solid black. The >0^oC warmer region (yellow and red in the color curve) is south of the Aleutians. There is a relatively cold patch just northeast of the warm patch, and a stronger boundary between warmer and -10^oC and colder than -10^oC across central Alaska. There is good agreement between the NUCAPS analysis and the GFS analysis of 850-mb temperature at that time (here, from the TropicalTidbit website)

Kodiak Island is very near a region of dry air as indicated by the NUCAPS profiles; relative humidity in the 850-500 mb layer is <20% per the gridded NUCAPS analysis. The toggle below compares the NUCAPS profiles near Kodiak Island (a green profile, at 1323 UTC) with the 1200 UTC sounding at Kodiak. In this case the soundings tell similar stories: a largely dry atmopshere, and the diagnosed levels (FZL, -20^oC and -30^oC) are similar.

The NUCAPS swath also includes Fairbanks and Utqiagvik, both with 1200 UTC soundings. Comparisons at those two sites are shown below. NUCAPS near Fairbanks does capture the near-saturation in the snow-growth region of the atmosphere, and the tropopause height is in agreement; however, the low-level saturation and low-level inversion in the rawinsonde is not in the NUCAPS profile. If a forecaster had access to AMDAR/MADIS profiles from aircraft at the same time, that near-surface NUCAPS deficiency could be mitigated.

The comparison at Barrow/Utqiagvik, below, shows some similarities: the dry slot at mid-levels with relatively moist regions near the surface and below the tropopause. As you make the comparison between NUCAPS and rawinsondes, always recall the very coarse vertical resolution in NUCAPS profiles.

Gridded NUCAPS fields are also available at this SPoRT site, supplying views as shown below.

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The SPoRT site above also contains microwave estimates of snowfall rate, derived using MIRS algorithms and (for the time shown) ATMS data from NOAA-20. Widespread light snow is indicated, as might be expected by the saturation in the snow growth region within the Fairbanks sounding.

Snowfall rate is also available at this UMD site where data from more satellites are available. Note the similarities in the two fields of snowfall rate from the two sites for the same overpass.

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