Tutuila, the large island of American Samoa, experienced very heavy rain early in the morning of 21 March 2023, especially over the western parts of the Island. (However, the raingauge at the Pago Pago airport, in central Tutuila, received only 0.15″ of rain!) The animation above shows the development of convection in a corridor of moisture as suggested by the Total Precipitable Water (TPW) fields. Values diagnosed by the GOES-R algorithm exceed 2.1″ (magenta) near the clouds vs. values around 1.8-1.9″ (yellow/orange enhancement) to the east and to the west. How confident are you that that ribbon of moisture is true, and perhaps not an artifact of the clouds? TPW fields from gridded NUCAPS, below, (from this site), also show a local maximum in TPW oriented southeast-to-northwest over the Samoan Islands. MIMIC Total Precipitable Water from 1500 UTC on the 21st, shown here, from this site, also show the local maximum.

The animation below shows GOES-18 Band 13 infrared (10.3 µm) imagery, the Level 2 Rain Rate product, and that Rain Rate product overlain on top of the low-level water vapor infrared imagery (Band 10, 7.34 µm), all centered on the island of Tutuila. Very heavy rain is diagnosed over western Tutuila, with values exceeding 1.9″/hour, values that are red in the enhancement used. This is more easily viewed in the animation at bottom.

A zoomed-in look at GOES-18 Rain Rate, below, from 1430-1530 UTC, shows when the heaviest rain was falling over the island; orange/red values are close to 2″/hour. The GOES-R Rain Rate Level 2 product is not parallax-corrected, so it is displayed a bit farther from the sub-satellite point (at 137^oW, or about 33^o longitude from Tutuila) than it is in reality.

This was a case where the GOES-R product diagnosed much heavier rain than JAXA’s GsMAP (shown below in an animation) or CMORPH fields (available at RealEarth).

View only this post Read Less

Rotation off the coast of California near San Francisco was present on Tuesday 2023-03-21 as the area got hit with rains and high windspeeds. The rotation is apparent in both visible RGB satellite imagery and radar reflectivity, animated below using RealEarth. Circular formations in cloud structure, seen by GOES-16, and rain bands picked up in the radar, are visible.

Flood advisories have been issued along much of the state of California, including Los Angeles and Orange Counties. Windspeeds as high as 102 mph were reported near Santa Clarita, CA and 74 mph in Oakland, CA.

California isn’t the only state in the region to experience an excess in rain. Much of central and Northern Arizona are also under flood warnings. Below, the ‘Excessive Rainfall Outlook’ product is displayed in RealEarth. The Excessive Rainfall Outlook is a forecast of the likelihood that rainfall will exceed flash flood guidance (FFG) at a point. This product is issued by the Weather Prediction Center (WPC).

More than 121,000 Californians were without power Wednesday morning and two have been killed by fallen trees.

View only this post Read Less

By animating daily NOAA GOES-16 ABI Full Disk true color imagery, how the Earth is illuminated over time can be seen. For example, how the terminator falls on the Earth until the Equinox. For details, see “What is a Solstice?” by SciJinks. Or this NOAA post.

11 UTC loops from the (northern hemisphere) fall Equinox to the Spring Equinox. These posted GOES ABI Full Disk imagery are only showing a small number of the pixels, for a fuller resolution image at one time (20-March-2023).

The above loop, and a smaller size. The 16 bands of ABI from GOES-West and GOES-East from UW/CIMSS.

Interactive web page

An interactive web page with half a years worth of GOES ABI Full Disk visible images at 11 UTC. The beginning date is the (northern hemisphere) fall equinox in 2022 and the end date is the spring equinox in 2023. A user can play the animation, as well as annotate the images. For example, draw lines along the terminator for different times of the year. One example might be to compare a solstice to an equinox. Can you estimate the day of the summery equinox? H/T Tom Whittaker, SSEC, for the webapp, as well as those below.

Webapps about the Seasons

H/T

These images were made using NOAA data with geo2grid software, from UW-Madison, SSEC. T. Whittaker is thanked for the webapps.

View only this post Read Less

GOES-16 (GOES-East) daytime True Color RGB and Nighttime Microphysics RGB images from the CSPP GeoSphere site (above) covered the period from 0200 UTC on 06 March to 0000 UTC on 20 March 2023 — and eventually showed the circulation of Cyclone Yaku off the coast of Peru (the clockwise circulation of Yaku was initially obscured by deep ITCZ convection, but became more evident around 11 March as the storm approached 10º S latitude). According to surface analyses from the NHC Tropical Analysis and Forecast Branch, Yaku apparently developed along the southern branch of the Eastern Pacific Double ITCZ sometime around 0000 UTC on 06 March (over an area of warm SST anomaly). As Yaku later began to move southward across colder water, deep convection diminished and its low-level circulation became more exposed from 15-19 March — and a distinct circulation was no longer seen by 0000 UTC on 20 March.

The MIMIC Total Precipitable Water product (below) revealed the clockwise circulation of Yaku on/after 04 March.

#Infórmate #Yaku, Ciclón de características tropicales no organizado, se ubica a más de 1600 Km de Lima y no ejercería influencia en la ocurrencia de lluvias sobre la costa y sierra del Perú.

?Líneas rojas, recorrido del 4 al 17 de marzo
?Líneas amarillas, probable recorrido pic.twitter.com/03aR9nI2SU

— Senamhi (@Senamhiperu) March 17, 2023

View only this post Read Less