The Storm Prediction Center’s Convective Outlooks for late afternoon on 19 January 2023 contained a region of Enhanced Probabilities for Severe weather (primarily for wind) over portions of Ohio, as shown above. The chief difference between the 1630 and 2000 UTC outlooks was the extension of the Enhanced region to the north/northeast by a county or two at 2000 UTC. The unusually strong convection (for January!) that developed over Ohio on 19 January 2023 did cause a large swath of wind damage as shown by the SPC Storm reports below, mostly in the northern part of the Enhanced Risk. Most of the winds reports occurred between 2200 UTC on 19 January and 0100 UTC on 20 January, and most were within the Cleveland, OH, County Warning Area (CWA). What kind of satellite data could have been used on 19 January for situational awareness as the storms developed?

The toggle above shows thermodynamic fields from NUCAPS profiles from a NOAA-20 overpass just after 1800 UTC. Clear skies (as suggested by the green dots in the AWIPS display) prevailed over much of Indiana and Ohio at this time. The steepest low-level (that is, 850-700 mb) lapse rates were centered over the central Indiana/Ohio border; the largest Total Totals index values, however, were a bit farther north.

Because skies were clear, GOES-16 Derived Stability Indices gave information/could be used on this day. The animation below combines GOES-16 Band 13 imagery (for cloudy regions) and the derived Lifted Index in clear regions. For both of these fields, the default AWIPS enhancements were changed (because, in part, it’s January!) The coldest Band 13 brightness temperatures were -80^oC (vs the default -109^oC) and the Lifted Index is scaled from 0-12 (vs. the default of -10 to 20). It is revealing that the smallest Lifted Indices (around 1 or 2) occur in the northern half of the Enhanced Risk polygon as the convection moves into western/central Ohio. (Here is a still image from 1951 UTC, two hours before the onset of convective wind reports). Could the satellite-diagnosed lower stability in the northern part of the Enhanced Risk (relative to the southern part) help in situational awareness, especially when combined with the NUCAPS snapshot shown above?

Derived CAPE, shown below (and scaled to just 0-50) shows a small region of positive CAPE over north-central Ohio around 2100 UTC.

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Note that the AWIPS default was changed in all the GOES-16 imagery/derived products shown above! Do not always rely on defaults. NUCAPS figures for this blog post were produced using the Product Browser on a TOWR-S Cloud Instance of AWIPS. Thanks!

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True color imagery from the CSPP Geosphere site, shown above (click here for a direct link to the animation), depicts the sudden appearance and equally sudden ending of a small fire on the Texas Gulf Coast in Jefferson County, east-northeast of Houston.

The Fire Temperature RGB also shows the quick development (and cessation) of the fire; this RGB is a good situational awareness tool, as it shows an obvious color change (related to the increase in emissions of shortwave radation) when the fire initiates.

GOES-R has derived products that quantify aspects of the detected fire, as shown in the four-panel image below from 1731 UTC, near the time when the fire was most intense. Note the contributions of the red and green components of the RGB, from the 3.9 µm and 2.25 µm channels, respectively, on GOES-16, have maximized in the center pixel, so that pixel is yellow in the RGB (red + green in an RGB yields yellow); had the 1.61 µm emissions been stronger (that is, had the fire been hotter), the pixel would look whiter. The Fire Products (Area, Temperature, Power) are most useful as data assimilated into models that might simulate the evolution of the fire, or the distribution of smoke.

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The Fire Temperature RGB is one of the few RGB products in AWIPS that has a gamma adjustment. A gamma adjustment alters how the ranges of input values (in this case, 3.9 µm brightness temperatures) are displayed. For the Fire Temperature RGB, the warmest parts of the 3.9 µm brightness temperatures occupy proportionally more of the display space in the RGB, and the cooler parts of the RGB (where fire is unlikely, yet information is still needed!) occupy less.

AWIPS allows a gamma adjustment to be altered (using the ‘Composite Options’ window). The toggle below compares the default RGB to one in which the Band 7 Gamma adjustment has been changed to Gamma = 1, resulting in a very red image (because cooler brightness temperatures — that are not that relevant to the detection of fire — are more emphasized).

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Note: AWIPS users might note that the default Gamma of the RGB is 2.5, but the Quick Guide shows the Gamma to be 0.4 (that is, 1/2.5)! This may be a source of confusion. This website shows a Gamma modification of 1/Gamma — and if Gamma is 0.4, that exponent becomes 2.5, which is what AWIPS shows.

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A multi-week “parade of storms” over the Pacific Ocean featuring a persistent atmospheric river pattern and numerous winter storms pounding the U.S. west coast has resulted in record snowpack in the Sierra Nevadas with water equivalency at 205% of normal for mid-January in the northern Sierras, 255% central, and 293% of normal for the southern Sierras. (Data relayed via NWS Sacramento from the California DWR) A break in the cloud cover on Tuesday January 17th enabled satellite views of the record snowpack and visual confirmation of the rising reservoirs.

Ground water is also replenishing making dents in the multi-year drought impacting the western United States.

Compare the weekly Drought Monitor maps (December 27th through January 17th) to see weekly improvements. Note how areas of Exceptional and Extreme drought conditions in California are eradicated during this time period.

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1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images (above) displayed the small eye-like feature associated with a warm seclusion that developed about 200 miles southeast of the New Jersey coast on 15 January 2023. Areas of deep convection around the periphery of the seclusion occasionally exhibited cloud-top infrared brightness temperatures around -50ºC.

During the preceding nighttime hours, a comparison of Suomi-NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images valid at 0718 UTC (below) provided a view of the cyclone as it was beginning to transition to its occluded phase — and the Sea Surface Temperature derived product indicated that water temperatures in the general vicinity were in the upper 60s to low 70s F (suggesting that the system was very near the axis of the Gulf Stream). One isolated bright lightning streak was seen in the Day/Night Band image, associated with a thunderstorm located near the warm front (which exhibited a cloud-top infrared brightness temperature of -56ºC).

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