A 999 low is located in Southeast Nebraska on April 19, 2023, swinging a cool front/dry line across the central and southern plains. Hail and wind are likely today; a 40% probability of isolated tornadoes will all be possible with this system. The best supercell parameter for EF-1 to EF-2 tornadoes will be near Falls City and east of Lincoln Nebraska on this run of the WALT Model 2. Slight Non-polar CH4 release is expected from tree stems, and shallow water systems such as creeks, rivers, and lakes. Slight NO3 .0063 to .0088 PPM levels are expected from CAPE buildup and polar positive lightning strikes to develop a severe weather threat. NO3 levels of .0063 to .0088 PPM will tighten with soluble H20 to create an atmosphere possible for ground tornado development. Surface measurements are running .32, .32, .23, .22, and .21 which indicates a 40% chance of tornadoes in Southeast Nebraska and a 20% probability of tornadoes across the remainder of the forecast region. A new parameter of hail and wind threshold has been developed which indicates a hail and wind surface measurement of .27. This indicates hail and wind will be a better chance than tornadoes with this system. Measurements are still below the.34 threshold of dangerous tornado potential. EF-0 to EF-2 tornadoes could play out as of the latest measurements in an isolated fashion, but the risk is slight along the dry line with afternoon heating but 40% near the surface low in Southeast Nebraska. The main reason for not increasing the severe threats along the dry line is that current measurements do not show they can overcome the ground inversion cap which is indicating parameters to be moderately positive .01 in portions of Kansas to .08 in Texas above the normal range.
Forecaster:
Climate Scientist Wayne Adams