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Man-Yi moves through the Marianas Islands

Day Night Band imagery from the three JPSS Satellites — NOAA-21 (1515 UTC), Suomi NPP (1537 UTC) and NOAA-20 (1602 UTC) show Tropical Storm Man-Yi as it approached the southern Marianas Islands early in the morning on 13 November 2024 (Guam Time). These images were created using CSPP Software and data... Read More

VIIRS Day Night Band visible (0.7 µm) imagery, 1515, 1537 and 1602 UTC on 12 November 2024 (click to enlarge)

Day Night Band imagery from the three JPSS Satellites — NOAA-21 (1515 UTC), Suomi NPP (1537 UTC) and NOAA-20 (1602 UTC) show Tropical Storm Man-Yi as it approached the southern Marianas Islands early in the morning on 13 November 2024 (Guam Time). These images were created using CSPP Software and data downloaded at the Direct Broadcast site on Guam. The Deep Convection with the system is close to the surface center. That was not the case 12 hours earlier!

Himiwari-9 visible imagery (Band 3, 0.64 µm), below (from this site), from 0300 – 0510 UTC on 12 November show a low-level swirl of clouds to the northwest of the deepest convection.

Himawari-9 Visible Imagery (Band 3, 0.64 µm), 0300-0510 UTC on 12 November 2024 (click to enlarge)

Shortwave infrared imagery from Himawari-9 (Band 7, 3.9 µm) shows the low-level circulation separate from the convection until about 1000 UTC. Shortly before that time, convection develops into and persists within the center of the low-level swirl of clouds.

Himawari-9 Shortwave Infrared imagery (Band 7, 3.9 µm), 0600-1300 UTC on 12 November 2024 (click to enlarge)

As of 0000 UTC on 13 November, the deepest convection with Man-Yi is passing south of Guam. Winds at the Guam airport are easterly, with gusts to 40 mph. The statement below was issued at 841 AM/13 November Chamorro Standard Time (2241 UTC on 12 November).


Thanks to Douglas Schumacher, CIMSS, for the Day Night Band imagery from Guam.

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The effect of deep snow cover on surface air temperature across eastern Colorado

GOES-16 (GOES-East) Red Visible images and the Land Surface Temperature derived product (above) showed a large area of relatively fresh snow cover across the Plains of eastern Colorado on 11th November 2024 — this deep snow cover was the result of a closed upper-level low which moved across the area 2-3 days... Read More

GOES-16 Red Visible images (0.64 µm, left) and Land Surface Temperature derived product (right), with/without an overlay of Surface Air Temperatures [click to play MP4 animation]

GOES-16 (GOES-East) Red Visible images and the Land Surface Temperature derived product (above) showed a large area of relatively fresh snow cover across the Plains of eastern Colorado on 11th November 2024 — this deep snow cover was the result of a closed upper-level low which moved across the area 2-3 days earlier, producing impressive accumulations. This significant snow cover was having a notable effect on surface air temperatures, keeping them anywhere from 10-20 F colder than adjacent areas of bare ground.

GOES-16 Red Visible image (0.64 µm, left) and Land Surface Temperature derived product (right) at 2001 UTC, with a cursor sample of the METAR surface report (red) and Land Surface Temperature (white) at Limon, Colorado (KLIC) [click to enlarge]

Over interior areas with deeper snow cover, cursor sampling of the Land Surface Temperature at Limon (above) and at La Junta (below) revealed values in the mid 30s F.

GOES-16 Red Visible (0.64 µm, left) image and Land Surface Temperature derived product (right) at 2001 UTC, with a cursor sample of the METAR surface report (red) and Land Surface Temperature (white) at La Junta, Colorado (KLHX) [click to enlarge]

At locations along or near the edge of the snow cover, their surface air temperature was somewhat cooler if winds were blowing off the snow pack. This effect was very apparent at Burlington (KITR) along the eastern edge of the snow cover, with cool NW winds keeping their air temperature in the upper 30s F (below).

GOES-16 Red Visible image (0.64 µm, left) and Land Surface Temperature derived product (right) at 2001 UTC, with METAR surface reports plotted in red [click to enlarge]

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Parade of tropical cyclones across the western Pacific

Total Precipitable Water fields over the western Pacific on 10/11 November 2024, above, show 4 tropical cyclones at different stages of development across the West Pacific. The screenshot from the Joint Typhoon Warning Center, below, shows the 4 storms: Yinxing, about to make landfall in Vietnam, Toraji pulling away from... Read More

Total Precipitable Water estimates across the Western Pacific, 1600 UTC 10 November – 1500 UTC 11 November 2024 (Click to enlarge)

Total Precipitable Water fields over the western Pacific on 10/11 November 2024, above, show 4 tropical cyclones at different stages of development across the West Pacific. The screenshot from the Joint Typhoon Warning Center, below, shows the 4 storms: Yinxing, about to make landfall in Vietnam, Toraji pulling away from the northern Philippines, Tropical Storm 27W in between the Marianas and the Philippines, and Man-yi moving through the Marianas. This screenshot from the CIMSS Tropical Weather website similarly shows the 4 storms lined up in a row.

Screenshot of JTWC front page, 0900 UTC on 11 November 2024 (Click to enlarge)

Himawari-9 imagery, below, shows the two easternmost tropical cyclones. Mid-level water vapor imagery shows dry(ish) mid-level air between the two systems; total precipitable water imagery from (say) 1200 UTC on 11 November also shows a filament of relatively dry air that might influence the development of Man-yi, the easternmost system, in the short term. Clean window infrared imagery shows strong convection intermittently over both systems.

Himawari-9 Mid-level Water Vapor (Band 9, 6.96 µm), left) and Clean Windown (Band 13, 10.41 µm), right) infrared imagery, 0400-1200 UTC on 11 November 2024 (Click to enlarge)

The Joint Typhoon Warning Center suggests Man-Yi will move mostly west towards Guam, affecting the Marianas between 0000 and 1200 UTC on 13 November (this is late in the day on the 13th on Guam). As noted in this Facebook Live recording (from the Science and Observation Officer on Guam), the forecast path for Man-Yi has been evolving with time. Interests throughout the Marianas and Micronesia show pay attention to advisories on this storm, both from JTWC and from the National Weather Service on Guam.


On 10 November, GCOM-W1 overflew the developing system. Microwave information at 89 GHz is shown below with derived AMSR-2 surface wind speeds (imagery from Brandon Aydlett, SOO at NWS Guam); the imagery was produced by CSPP software operating on data downloaded at the Direct Broadcast antenna on Guam. Microwave data revealed a sheared system. A low-level swirl is centered near 16oN Latitude, 154oE Longitude, note the curved bands to the west and north (darker blue in the enhancement) and deep convection (yellow/red/brown in the enhancement) to the southeast of the low-level swirl. Derived wind speeds show values exceeding 40 knots underneath the strongest convection. (You can view AMSR-2 windspeed at the NASA Worldview site as well here)

AMSR-2 89.0 GHz Brightness Temperatures (top) and derived Surface Wind Speeds. 1512 UTC on 10 November 2024 (Click to enlarge)

A basin-wide Shear Analysis, below, from the CIMSS Tropical Weather Site (link), shows strong shear over the system at 1500 UTC on 10 November 2024. Man-Yi’s convection was between 150o and 160o E Longitude, and around 13o N Latitude, as highlighted by the dark arrow below. Strong shear that is diagnosed over the system would displace the convection to the southeast of the near-surface circulation as shown in the microwave imagery above.

200-850 mb shear values, 1500 UTC on 10 November 2024, the arrow points to Man-Yi’s convective signature (Click to enlarge)

By 1500 UTC on 11 November, the shear over the system has weakened as the system approached 150o E Longitude. Slow strengthening is forecast. The northern Marianas Islands are all under a Tropical Storm Watch.

200-850 mb shear values, 1500 UTC on 11 November 2024; Man-Yi’s convective signature is just east of 150 E Longitude (Click to enlarge)

Thanks to Brandon Aydlett, WFO GUM for the alert about this storm and for the imagery. Thanks also to Douglas Schumacher for the GCOM-W1 imagery. Note that there is more Guam-centered GCOM-W1 89 GHz imagery on 11 November in this blog post.

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Jennings Creek Wildfire along the New Jersey-New York border

5-minute CONUS Sector GOES-16 (GOES-East) Nighttime Microphysics RGB + daytime True Color RGB images from the CSPP GeoSphere site (above) displayed the nocturnal thermal signatures (darker shades of violet) of a few wildfires in the vicinity or the New Jersey-New York border — particularly that associated with the larger and persistent Jennings Creek... Read More

GOES-16 Nighttime Microphysics + daytime True Color RGB images, from 2131 UTC on 8th November to 2106 UTC on 9th November [click to play MP4 animation]

5-minute CONUS Sector GOES-16 (GOES-East) Nighttime Microphysics RGB + daytime True Color RGB images from the CSPP GeoSphere site (above) displayed the nocturnal thermal signatures (darker shades of violet) of a few wildfires in the vicinity or the New Jersey-New York border — particularly that associated with the larger and persistent Jennings Creek Wildfire along the border — along with the distinct Jennings Creek Wildfire smoke plume that moved southeast across the New York City area and adjacent offshore waters during the day on 9th November 2024. The fire caused some local road closures, and there was 1 firefighter fatality.

GOES-16 Visible images with an overlay of the Fire Mask derived product (a component of the FDCA) (below) also displayed the Jennings Creek Wildfire thermal signature and smoke plume — plots of Ceiling and Visibility showed that this smoke occasionally reduced the surface visibility to 4-6 miles at a few of the New York City area airports (visibility in miles is the number plotted to the bottom left of each 4-letter station identifier).

GOES-16 Red Visible (0.64 µm) images, with an overlay of the GOES-16 Fire Mask derived product and hourly plots of Ceiling and Visibility (cyan) [click to play MP4 animation]

A Pilot Report over far northeast New Jersey at 1550 UTC (below) indicated the presence of heavy smoke (+FU) at an altitude of 1700 ft — which was restricting the flight-level visibility to 1-1/2 statute miles.

GOES-16 Red Visible (0.64 µm) image with an overlay of the GOES-16 Fire Mask derived product at 1551 UTC — and cursor sampling of a Pilot Report at 1550 UTC [click to enlarge]

GOES-16 Aerosol Optical Depth values over the NYC area were occasionally at or slightly above 1.0, as depicted by darker red pixels (below).

GOES-16 Red Visible (0.64 µm) image with an overlay of the GOES-16 Fire Mask and Aerosol Optical Depth (AOD) derived products at 1901 UTC — and cursor sampling of the LaGuardia Airport METAR (cyan) and nearby AOD value (yellow) [click to enlarge]

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