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NGFS detections over Logan County OK on 28 October 2024

The Storm Prediction Center’s Fire Weather Outlook, issued at 1700 UTC on 28 October (link), shown below, shows a critical weather day over portions of Oklahoma, Kansas and Texas. The forecast office in Norman, OK, noted the fire risk, Red Flag Warnings and Wind Advisories on its front page.The Next Generation Fire System Alerts Dashboard monitors satellite imagery to detect the hot spots that indicate wildfires. A screen... Read More

The Storm Prediction Center’s Fire Weather Outlook, issued at 1700 UTC on 28 October (link), shown below, shows a critical weather day over portions of Oklahoma, Kansas and Texas. The forecast office in Norman, OK, noted the fire risk, Red Flag Warnings and Wind Advisories on its front page.

Storm Prediction Center Fire Weather Outlook, 1700 UTC on 28 October 2024

The Next Generation Fire System Alerts Dashboard monitors satellite imagery to detect the hot spots that indicate wildfires. A screen capture of the Alerts Dashboard is shown below (The Alerts Dashboard has been modified so only alerts in TX and OK are shown), with an alert shown for Logan County in OK, north of Oklahoma City OK. By clicking on the triangle, satellite data associated with alert can be accessed.

NGFS Alerts Dashboard with a fire detected over Logan County OK (Click to enlarge)

The satellite imagery revealed once a user clicks on ‘Satellite Imagery’ above is shown below. This shows the NGFS Microphysics RGB. In addition, the pixels where the fire has been detected are highlighted; the color of the pixel outline is a function of the estimated GOES-R derived Fire Radiative Power. The slider allows a user to move forward and backward in time to help conclude if action is required. Note also the button that says ‘Open in RealEarth’. That opens a RealEarth instance that includes all the NGFS fire products.

NGFS Prototype showing a detected Hot Spot west of Langston OK, 1746 UTC on 28 October 2024 (Click to enlarge)

The RealEarth instance of NGFS, for the same time, is shown below.

RealEarth instance of NGFS detection near Langston OK, 1746 UTC on 28 October 2024 (Click to enlarge)

The animation below shows Fire Temperature RGB and NGFS Microphysics RGB animations from 1721 to 1836 UTC. The fire detection in both RGBs shows up at 1746 UTC. High clouds mean it is a challenge to maintain the RGB signal, but the NGFS signal persists as high clouds move overhead.

Fire Temperature RGB (left) and NGFS Microphysics RGB imagery, 1721 – 1836 UTC on 28 October 2024 (Click to enlarge)

CSPP Geosphere true-color imagery, below, shows a complicated scene. The moving high clouds make it difficult to identify — visually — any fire detections.

CSPP Geosphere GOES-16 Mesoscale Sector 1 true-color imagery, 1742-1948 UTC on 28 October 2024

The CIMSS Prototype NGFS website is here.

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Light snow moves across central Alaska

GOES-18 Airmass RGB imagery, above, from 1500-1820 UTC on 28 October, show light snow over much of central Alaska as a storm system moves into the state. Temperatures at 500 mb, below, derived from NUCAPS profiles (as shown in the toggle), show a tongue of warmer air positioned with the cloud feature (shown as white) in... Read More

GOES-18 Airmass RGB, 1500-1820 UTC on 28 October 2024 (click to enlarge)

GOES-18 Airmass RGB imagery, above, from 1500-1820 UTC on 28 October, show light snow over much of central Alaska as a storm system moves into the state. Temperatures at 500 mb, below, derived from NUCAPS profiles (as shown in the toggle), show a tongue of warmer air positioned with the cloud feature (shown as white) in the RGB above. Temperatures in that warm(ish) tongue of air (bluish in the enhancement) are around -25 to -27oC versus the Bering Sea (magenta in the enhancement) where they are around -35oC. Temperatures at 850 mb over the Bering Sea (shown here with a color enhancement that ranges from -25oC to +10oC) are around -6oC.

500-mb temperatures from gridded NUCAPS, 1330 UTC on 28 October 2024 (Click to enlarge)

Snowfall Rates, estimated from ATMS on Suomi-NPP (from this site) show snow moving slowly north between 1324 and 1504 UTC over western Alaska.

S-NPP estimates of Snow Fall Rate (sfr), 1324 and 1504 UTC on 28 October 2024 (click to enlarge)

Did your eye jump on the heavier Snowfall rates over southern Alaska? The region around Anchorage is in a Winter Storm Warning; 6-12″ is expected, more than the lighter values expected across the central part of the state.

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Flooding on Maui and Oahu

Infrared imagery over the Hawai’ian Islands on 25/26 October, below, shows convective development over Maui and Oahu. This was also a region of strong vertical wind shear, as shown below, as upper level cloud features were moving southeastward, low level clouds were moving to the west).GREMLIN is a machine-learning tool... Read More

GOES-18 Band 13 (Clean Window infrared, 10.3 µm) imagery, 1411 UTC 25 October through 0001 UTC 26 October 2024 (Click to enlarge)

Infrared imagery over the Hawai’ian Islands on 25/26 October, below, shows convective development over Maui and Oahu. This was also a region of strong vertical wind shear, as shown below, as upper level cloud features were moving southeastward, low level clouds were moving to the west).

850-200 mb wind shear, 1800 UTC on 26 October 2024 (Click to enlarge)

GREMLIN is a machine-learning tool that uses Bands 7, 9 and 13 fields from GOES-18 to emulate what NEXRAD radar echoes might look like. The animation below shows GOES-18 infrared data, and GREMLIN radar estimates. GREMLIN shows radar returns over both Oahu and Maui.

GOES-18 Band 13 (Clean Window infrared, 10.3 µm) imagery (left) and GREMLIN Radar Emulation (dBz, right), 1411 UTC 25 October through 0001 UTC 26 October 2024 (Click to enlarge)

Strong convection with radar returns occur over both Maui and Oahu after 1500 UTC. The National Weather Service in Honolulu issued Flash Flood Warnings at 1638 UTC for Maui and at 1640 UTC for Oahu. The side-by-side animation, from 1501-1701 UTC shows the heavy rain indicated by GREMLIN as the Flash Flood Warning was issued.

GOES-18 Band 13 (Clean Window infrared, 10.3 µm) imagery (left) and GREMLIN Radar Emulation (dBz, right), 1501-1701 UTC 25 October 2024 (Click to enlarge)

The Hilo sounding from 1200 UTC on 26 October, below, (from here) shows a moist atmosphere (55 mm of Total Precipitable Water) and mid-level instability. MIMIC Total Precipitable Water (TPW) at that time (here) shows the horizontal distribution of the moisture.

Upper-air sounding at Hilo HI (91285) at 1200 UTC on 26 October 2024 (Click to enlarge)

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Strong winds south of a low pressure system in the Beaufort Sea

A sequence of Suomi-NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images (above) showed the cyclonic swirl of clouds associated with a low pressure system that was moving eastward across the Beaufort Sea on 25 October 2024. The relatively tight pressure gradient south of this low (surface analysis)... Read More

Sequence of Suomi-NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images, with an overlay of METAR site surface winds (white) and Peak Wind gusts (cyan/red) on 25 October [click to play MP4 animaton]

A sequence of Suomi-NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images (above) showed the cyclonic swirl of clouds associated with a low pressure system that was moving eastward across the Beaufort Sea on 25 October 2024. The relatively tight pressure gradient south of this low (surface analysis) was forcing fairly strong W-SW winds across the North Slope and Arctic coast of Alaska (as well as the adjacent Canadian provinces of Yukon and the Northwest Territories).

A Suomi-NPP VIIRS Day/Night Band image with an overlay of Metop-B ASCAT winds (below) depicted the flow across the offshore waters north of Alaska — where Heavy Freezing Spray Warnings were issued for the ice-free waters. Numerous ASCAT wind speeds were in the 30-35 knot range.

Suomi-NPP VIIRS Day/Night Band (0.7 µm) image, with an overlay of METAR site surface winds (white) and Peak Wind gusts (cyan/red) and Metop-B ASCAT winds (green) [click to enlarge]

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