1. Synthetic Satellite Imagery: A New Tool for GOES-R User Readiness and Cloud Forecast Visualization Dan Lindsey NOAA/NESDIS, SaTellite Applications and Research (STAR) Regional And Mesoscale Meteorology Branch (RAMMB) Louie Grasso and Dan Bikos CIRA/Colorado State University, Fort Collins, CO 80523-1375 Fort Collins, CO 80523-1375 E-mail: Dan.Lindsey@noaa.gov Introduction For the past several years, synthetic satellite imagery has been produced at the Cooperative Institute for Research in the Atmosphere (CIRA) in collaboration with the NOAA/NESDIS/StAR Regional and Mesoscale Meteorology Branch. Output from convection-resolving models is used as input to a radiative transfer model, which calculates the brightness temperatures expected from satellites. The result is a time series of forecast satellite images. Synthetic imagery of spectral bands from the GOES-R Advanced Baseline Imager are currently being used in training efforts for the National Weather Service (NWS). It is very beneficial for forecasters to preview the type of information that will become routine from GOES-R in less than 2 years. Another huge benefit is that synthetic imagery is an excellent visualization tool for clouds from these high resolution models. The NWS offices that are receiving the data in real time from CIRA have provided overwhelmingly positive feedback. This poster provides examples of various uses for synthetic satellite imagery. Synthetic Imagery Production Output from the high resolution (<=5 km), including geopotential height, temperature, water vapor, and microphysical variables such as cloud water and ice are sent to CIRA This data is used as input to the Community Radiative Transfer Model, which then outputs simulated satellite brightness temperatures at various wavelengths/bands The brightness temperature fields are converted to various formats, including AWIPS-1, AWIPS-2, and NAWIPS, to be used by the National Weather Service’s operational display software Model Visualization – Example 1 http://rammb.cira.colostate.edu/ramsdis/online/goes-r_proving_ground.asp Questions? Send email to Dan.Lindsey@noaa.gov. The views, opinions, and findings in this report are those of the authors, and should not be construed as an official NOAA and or U.S. Government position, policy, or decision.Dan.Lindsey@noaa.gov 3-4 Figure 1: This shows a comparison between the 19-hour forecast 10.35 μm ABI Band 13 image from the NSSL-WRF (left) and the corresponding observed GOES-15 10.7 μm image (right). The model is forecasting formation of a mountain wave cloud over Colorado’s Front Range, and the observed imagery shows that this indeed occurred. Its horizontal extent isn’t perfect, but it provided forecasters the information that mountain wave clouds could form. Here is a portion of the Area Forecast Discussion (AFD) from the Denver/Boulder NWS office that day: AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER/BOULDER CO JAN 30 2012 …SO OVERALL SHOULD SEE WARMER MAXIMUM TEMPERATURES OVER YESTERDAY. HOWEVER UPPER LEVEL MOISTURE WILL BE INCREASING LATER THIS MORNING AND SYNTHETIC SATELLITE IMAGERY SHOWING MORE WAVE CLOUDS FORMING BY EARLY AFTERNOON. DEPENDING ON THE THICKNESS...THIS MAY KEEP HIGHS CLOSE TO YESTERDAY MAINLY ALONG THE URBAN CORRIDOR… Figure 2: In addition to simulating single bands, we can also simulate band differences. Here, we have calculated the 10.35 – 3.9 μm difference (left) based on a 12-hour forecast and applied a color table to highlight low liquid water clouds as blue. The corresponding GOES-13 fog and low cloud product (right) shows that these clouds did indeed form, and were more extensive than the model suggested. Below is a portion of an AFD from the Austin-San Antonio NWS office discussing this forecast. AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX 626 PM CDT SUN SEP 23 2012 … AVIATION… CONVECTION ALONG THE SEA-BREEZE BOUNDARY WILL REMAIN SOUTH OF KSSF AND KSAT AND WILL DISSIPATE AFTER SUNSET WITH THE LOSS OF DAYTIME HEATING. OTHERWISE THE CU FIELD THIS AFTERNOON IS AN INDICATION OF INCREASING LOW LEVEL GULF MOISTURE ACROSS SOUTH CENTRAL TEXAS. THE 18Z NAM X-SECTIONS DEPICT GOOD MOISTURE BELOW 925MB AT KSAT AND KSSF BUT SHALLOWER AT KAUS AND SOMEWHAT DRIER AT KDRT. THE 12Z CIRA WRF SIMULATED FOG/LOW CLOUD PRODUCT IS VERY BULLISH ON STRATUS FORMATION OVERNIGHT. WE HAVE HAD GOOD RESULTS WITH THIS EXPERIMENTAL PRODUCT AND THE TERMINAL FCSTS WILL BE BASED ON ITS SOLUTION. MVFR CIGS WILL REACH KSSF AROUND 09Z…KSAT AT 0930Z AND KAUS BY 12Z. THE STRATUS WILL ALSO SPREAD WESTWARD REACHING KDRT BY 13Z. THE STRATUS WILL LIFT AND MIX OUT WITH VFR CONDITIONS PREVAILING BY 16Z. Model Visualization – Example 2 Model Improvement – Example 1 Model Improvement – Example 2 Figure 4. a) Observed and b) synthetic 10.7 µm satellite imagery valid at 00 UTC on 11 April 2013, c) histograms of observed (solid lines) and synthetic (dashed lines) brightness temperatures corresponding to the images over all brightness temperatures, and d) zoomed in the denoted box for brightness temperatures between 190 K and 250 K. The synthetic image is based on a 24 hour forecast from the NSSL WRF. These figures highlight how the NSSL WRF underforecasts convectively generated cirrus clouds. Figure 3: A comparison of the simulated 10.35 μm band (left column) with the corresponding observed GOES-15 10.7 μm band (right column). The images on the left are all based on forecasts from the NAM Alaska Nest from 00Z on 15 Feb. 2015. Some features of interest are denoted on the figure. Work is currently underway to figure out a better particle size estimation method in order or reduce the brightness temperature biases exhibited above.