Summertime convection poses a number of forecasting challenges in the southeastern United States. Many of the challenges surround threat assessment and warning decision-making (a post for another day), but these “pop-up” showers and thunderstorms can also wreak havoc on temperature forecasts by introducing rain-cooled air and additional cloud cover. Fortunately, the SPoRT ADAS is proving to be very beneficial when it comes to short-term temperature updates.
This particular example dates from May 26. During the late afternoon and evening hours, a cluster of showers and thunderstorms developed in northeast Alabama and propagated westward due to outflow boundary motion. A quick glance at the SPoRT ADAS temperature analysis for 2300 UTC/6 PM CDT indicated that the thunderstorms had significantly lowered temperatures over the eastern portion of the Huntsville forecast area, detail which the original forecast grid could not incorporate. The SPoRT ADAS also picked up on increased heating across northwest Alabama.
Since NWS Huntsville ingests the SPoRT ADAS into GFE, it was easy to incorporate the analysis grids into the forecast and adjust accordingly (aided by a smart tool dedicated to copying analysis data into the forecast). Using the ADAS in this particular case meant the temperature forecast more accurately indicated nearly steady overnight temperatures across northeast Alabama early on, then eventually across much of the Huntsville forecast area.