There is a Marginal Severe Storm Risk for our location. Continue reading for today’s outlook from the National Weather Service’s Storm Prediction Center.
URGENT – IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service Flagstaff AZ 216 AM MST Mon Sep 12, 2022, Grand Canyon Country-Coconino Plateau-Yavapai County Mountains- Little Colorado River Valley in Coconino County-Little Colorado River Valley in Navajo County-Little Colorado River Valley in Apache County-Western Mogollon Rim-Eastern Mogollon Rim-White Mountains- Northern Gila County-Yavapai County Valleys and Basins-Oak Creek and Sycamore Canyons- Including the cities of Munds Park, Young, Winslow, Seligman, Tuba City, Sedona, Show Low, Williams, Strawberry, North Rim, Grand Canyon Village, Flagstaff, Bagdad, Greer, Valle, Heber, Wupatki N.M., St. Johns, Springerville, Happy Jack, Ash Fork, Cottonwood, Camp Verde, Supai, Holbrook, Pinetop, Payson, Prescott, Snowflake, Forest Lakes, and Cordes Junction 216 AM MST Mon Sep 12, 2022,/316 AM MDT Mon Sep 12 2022/ …FLOOD WATCH IN EFFECT THROUGH LATE TONIGHT… * WHAT…Flash flooding caused by excessive rainfall is possible. * WHERE…Portions of northern Arizona, including Yavapai, northern Gila, Coconino, Apache, and Navajo counties. * WHEN…Through late tonight. * IMPACTS…Flash flooding will be possible in creeks, normally dry washes, swimming holes, and over recently burned areas. Low-water crossings could also experience flash flooding, which would create deadly travel conditions. * ADDITIONAL DETAILS… – Visit www.weather.gov/safety/flood for more information on flood safety. PRECAUTIONARY/PREPAREDNESS ACTIONS… You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued.
AZ Widely scattered to scattered thunderstorms are possible today over the outlook area, offering sporadic strong/isolated severe gusts and isolated, marginally severe hail. Morning clouds/convection across primarily the central/northern parts of the outlook area are diminishing based on radar and satellite imagery — a trend that should continue through the early afternoon. Airmass recovery from the prior day’s convection — not always a given this time of year — also will be aided from south to north by theta-e advection ahead of the slowly ejecting mid/upper trough. The next/diurnal round(s) of convection should initiate both over areas of heated higher terrain in the northern and eastern parts, but also across the deserts and smaller Sky Island ranges of southern AZ, where diurnal destabilization will be longer and stronger. Activity already over the Mogollon Rim will only have a narrow corridor of favorable boundary-layer air to support wind/hail potential before moving farther north to northeast and dissipating but may send outflows southwestward to lower elevations. Initially separate convection over the central/southern parts, however, should move over well-mixed, deeper sub-cloud layers across the deserts, with large-scale lift related to the approaching trough overlying favorable moisture and weak MLCINH near the surface. Steep low/ middle-level lapse rates will contribute to MLCAPE generally around 1500 J/kg (locally higher), based on a modified 12Z TUS RAOB and model soundings. Outflow collisions/interactions may support additional development into the evening before stabilization from both diabatic cooling and outflow spread will lessen convective organization/coverage.