Atmospheric River to Impact the Northwest; Windy Conditions in the Northeast

A strong atmospheric river moving into northern California later today will bring a threat for moderate to heavy rainfall and flooding, gusty to high winds, and mountain snows for parts of the Northwest U.S. through Wednesday. Gusty winds and isolated showers are expected today in the Northeast U.S. behind a cold front. Wind Advisories have been issued. Read More >

Background

The lightning images below are updated daily around 7:30–8:30 AM and contain 24-h accumulations of lightning ending at 6 am MDT (5 am MST) each day. There are two sets of images for (1) NLDN cloud-to-ground flashes only and (2) GOES-East Lightning Mapper (GLM) cloud flash points. Option #1 only represents cloud-to-ground lightning flashes, and is based on a surface detection network. Option #2 does not discriminate between cloud-to-ground versus in-cloud flashes (i.e., it represents the total lightning) and is based on satellite. In-cloud lightning flashes can comprise 60–90% of the total lightning (i.e., most lightning does not reach the ground). Satellite-based lightning detection also does not depict the exact location where the flash occurred because of an issue known as "parallax." Mouse over each day to view the 24-h cumulative lightning flash maps. Printable versions are at the bottom of each of the three map segments.