Do it quickly if you wish to track the storm’s growing impact. The map tracks rainfall levels that have registered as recently as within the last 15 minutes and as far out as two weeks earlier.

As the storms plowed through western Arizona on their way toward the north-central and eastern Arizona mountains on Thursday, the color-coded precipitation levels could be seen changing at each of the hundreds of rain gages operated by the various participating agencies of the AFWS. Dots depicting data received from each gage would change in color from light blue (0.00 – 0.25 inches of measurable rain) to darker blue (0.25 – 0.50 inches), all the way up to red (greater than 2.00 inches of precipitation).

“I’m just looking at a rain gage that is owned by Maricopa County and it’s on the 101 (Inner Loop) and Bell, and it’s showing 79/100^th of an inch,” said Brian Cosson, Flood Warning Coordinator for the Arizona Flood Warning System, a consortium of government agencies that funnel data from their rain gages located across the state into the AFWS.

Cosson was marking those readings at about 3 p.m. on Thursday: “Eight-tenths of an inch of rain – that’s pretty significant,” said Cosson. “And that’s one of the higher readings in Maricopa County, so far,” he said.

In the person of Cosson, the Arizona Department of Water Resources coordinates the rain and flood data provided by the agencies in order to get it into the public realm as quickly as possible.

As the big winter storms began intensifying in mid-afternoon on Thursday, dots on the AFWS amp depicting rain gages began changing more rapidly. In Mohave County near the Colorado River, for example, numerous pink “dots” began appearing, indicating rainfall in excess of an inch. In south-central Arizona, meanwhile, the map began to solidify in dark blue, indicating rainfall totals of between .50 – 1.00 inches.

As with most of the tech-based services provided by ADWR, the AFWS precipitation map remains a work in progress.

“We’re going to be soliciting comments from end-users looking for how to enhance it,” said Cosson.

Meanwhile, storm trackers looking to follow the impact of these winter storms on the Colorado River system snowpack can get up-to-date snowpack information from the U.S. Bureau of Reclamation’s snowpack conditions map or the Colorado Basin River Forecast Center's conditions map.

Also, weather and storm updates from Maricopa County’s weather outlook map.