5-minute PACUS Sector GOES-18 (GOES-West) daytime True Color RGB and Nighttime Microphysics RGB images created using Geo2Grid (above) revealed the cyclonic circulation of a Mesoscale Convective Vortex (MCV) that migrated west-northwestward across southern Arizona into southeast California during the 2-day period from 16 July to 18 July 2025. This MCV emerged from a dissipating  cluster of thunderstorms over far southeast Arizona after about 0900 UTC on 16 July — and was moving through an environment of moisture and instability that was favorable for additional convective development.

This MCV was highlighted in NWS/WPC Mesoscale Precipitation Discussions on 16 July, 17 July and 18 July — since these middle-tropospheric features were helping to force the development of new thunderstorms, further enhancing flash flooding risks in the vicinity of the MCV.

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1-minute Mesoscale Domain Sector GOES-18 (GOES-West) GeoColor RGB images with an overlay of Next Generation Fire System (NGFS) Fire Detection polygons (above) showed the rapid growth of the Cram Fire in central Oregon during the day on 14 July 2025. Strong westerly winds helped to transport a dense veil of smoke eastward. This wildfire had started on the previous day, but exhibited extreme behavior on 14 July — growing to 10000 acres, and forcing some evacuation orders to be issued.

1-minute GOES-18 Visible images with an overlay of the FDCA Fire Mask derived product (below) also displayed the large thermal signature of the Cram Fire as it burned in the vicinity of the Wasco/Jefferson County line. Data from RAWS sites showed that winds just northeast of the fire were gusting as high as 40 mph at 2300 UTC.

An overpass of Landsat-9 provided a 30-meter resolution image of the Cram Fire at 1844 UTC on 14 July, viewed using RealEarth (below). The active fire front appeared as brighter shades of pink, with the burn scar exhibiting darker shades of orange-brown.

Several hours after sunset, a NOAA-20 VIIRS Day/Night Band image (below) displayed the bright nighttime glow of the Cram Fire (located between Antelope and Madras)  — both the northern and southern flanks of the wildfire were still actively burning at that time.

===== 15 July Update =====

After the overnight southward passage of a cold front, a transition to north-northeast winds began to transport dense wildfire smoke southwestward and southward on 15 July (above) — with this smoke occasionally reducing the surface visibility to 4 miles at Madras and 1.75 miles at Redmond. The Cram Fire continued its trend of very rapid growth, burning an area over 28000 acres by late morning, increasing to over 64000 acres by the end of the day (remaining 0% contained); evacuation orders were expanded as a result. In addition, Highway 97 near Willowdale was briefly closed early in the day, due to the close proximity of the fire (and its dense smoke creating hazardous driving conditions).

With RAWS sites surrounding the fire reporting N-NE wind gusts in the 25-30 mph range, the GOES-18 Fire Mask (below) showed that most of the burning activity shifted to the southern flank of the Cram Fire as the day progressed. The large burn scar exhibited darker shades of gray in the Visible imagery.

A toggle between NOAA-20 VIIRS Day/Night Band images during the post-sunset nighttime hours on 15 July and 16 July (below) showed a notable south-southwestward shift in the larger, more active fire front along the Cram Fire southern flank.

Toggles between VIIRS Day Fire RGB images from NOAA-20, NOAA-21 and Suomi-NPP on 14 July and 15 July (below) also showed the dramatic increase in fire size within ~24 hours. Areas of active fires showed up as brighter shades of red, while the burn scar appeared as darker shades of reddish-brown.

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10-minute Full Disk scan GOES-19 (GOES-East) Infrared images combined with the Fire Mask derived product (above) showed a wildfire in western Ontario (north of Red Lake, CYRL) that produced a large pyrocumulonimbus (pyroCb) cloud beginning at 1930 UTC — when cloud-top infrared brightness temperatures first reached -40ºC, darker shades of blue — on 10 July 2025. The wildfire was intensifying in advance of an approaching warm front (SW winds at Red Lake were gusting to 19-20 knots).

The pyroCb — which eventually merged with other nearby meteorological thunderstorms — exhibited cloud-top infrared brightness temperatures as cold as -67.75ºC at 2150 UTC (above).

In a plot of rawinsonde data from Pickle Lake, Ontario (CYPL) at 0000 UTC on 11 July (below), the -67.75ºC cloud-top temperature corresponded to an overshoot of the Equilibrium Level (EL) / Tropopause of nearly 1 km.

This pyroCb cloud produced a notable amount of lightning (beginning at 1950 UTC), as seen from overlays of GOES-19 GLM Flash Extent Density and Flash Points (below).

A toggle between NOAA-21 VIIRS GeoColor RGB images (with an overlay of NOAA-21 VIIRS Fire Radiative Power) at 1755 UTC and 1943 UTC is shown below (source). The later image displayed the pyroCb cloud shortly after its formation, as it had begun drifting eastward away from the large wildfire.

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2025 has proven to be an atypically wet year for American Samoa. The cumulative precipitation chart backs that up: going back to 1 January, the total rainfall at Pago Pago has been the highest on record up to this date, and total rainfall is 70% higher than a normal year.

July has been no exception to this trend. With nearly 9 inches of rain as of 8 July, the Pago Pago airport has already exceeded the normal value for the entire month. These trends are going to continue for quite some time, however. The CIMSS MIMIC product quantifies the total precipitable water present in the atmosphere, and it indicates an atmospheric river stretching from New Guinea to the Samoan archipelago and beyond into the southeastern Pacific.

MIMIC indicates TPW values of approximately 2 inches, which is confirmed by the radiosonde launches from Pago Pago. The calculated precipitable water is 49.22 mm, which is a little over 1.9 inches. While this is slightly reduced compared to earlier in the week (values as high as 2.2 inches were observed), this can still result in a substantial amount of rain. Given the significant amounts of rain that have already occurred, the ground is saturated and flash flooding is a concern. The lowest levels of the atmospheric profile are quite saturated, in fact, helping to bolster the idea of substantial rain.

Given the continued flow of moisture from the equatorial western Pacific as seen from MIMIC, the chances for rain in American Samoa remain significant as long as appropriate lifting mechanisms are present. The right amount of low-level convergence, for example, can be enough to force enough upward motion to initiate convective rain. Unfortunately, the most recent ASCAT overpasses just missed American Samoa, makinng it a challenge to directly observe low-level convergence over the islands.

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