UA WRF Forecast Discussions

  Synopsis Weak ascent induced by an upper level low over Arizona combined with differential heating of terrain and modest buoyancy will be responsible for scattered showers and a few isolated thunderstorms across the eastern part of the state today. Greatest coverage of precipitation will be mainly confined to the higher terrain with decreased chances in the lower elevations. Showers and storms will be capable of producing brief heavy rain, small hail, gusty winds, and occasional lightning flashes. Rainfall amounts will be light and highly variable and dependent on storm frequency, coverage, and intensity with UA WRF forecasting a trace to 0.10 inch in the lower deserts and between a trace and 0.25 inches over the higher terrain. Snow levels will remain mainly above 7000 feet with a dusting to 2 inches possible, with highest amounts expected over the White Mountains. Discussion Visible satellite imagery this morning displays scattered, developing cumulus clouds...

Synopsis A low pressure system will move eastward across the Southwest generating gusty winds, cool temperatures, and widespread precipitation tomorrow across the state. Strong southwesterly are likely across the lower deserts (including Tucson and Phoenix) tomorrow morning and early afternoon ahead of the primary cold front. Rainfall amounts will range from a few hundredths to 0.25 inches in the lower deserts and between 0.25 and 1 inch over the mountains. Snow levels are expected to remain above 5000 feet with total snowfall amounts between 1 and 6 inches with higher amounts likely over the tallest mountain peaks above 8000 feet. There is a chance for a few isolated thunderstorms tomorrow due to just enough buoyancy, so a few lightning strikes and small hail are possible.  Current Conditions As of 2:45PM MST this afternoon, southwest regional satellite imagery overlaid with 500mb RAP analysis displays an upper level trough off the California Coast, s...

Synopsis An upper level trough moving eastward into the Desert Southwest will bring cooler temperatures, gusty winds, and chances for precipitation across Arizona through Friday evening. Today will be breezy across the state, and precipitation chances will remain mainly confined to the higher terrain of Northern Arizona due to strong orographic enhancement. By late tonight into tomorrow morning, a vorticity maxima will generate widespread valley rain and mountain snow showers across the state. Rainfall amounts will range from a trace to 0.50 inch in the lower deserts and between 0.5 and 1.5 inches over the mountains, with highest amounts over the Mogollon Rim. Snow level will fall to around 4000 feet tomorrow morning with models forecasting a trace to 6 inches between 4000 and 6000 feet and between 6 and 12 inches above 6000 feet with locally higher amounts possible over the tallest peaks of Northern Arizona.  Over the weekend, high amplitude ridging rebuilds into th...

Synopsis A low pressure system in Southern California will gradually move eastward into Arizona leading to unsettled weather through Wednesday night. Precipitation will mainly impact the higher terrain in Northern Arizona today and tomorrow with precipitation chances increasing in Southern Arizona on Wednesday. Rainfall amounts will be light and variable with a trace to 0.25 inches in the lower deserts and between 0.25 and 0.75 inches over the higher terrain with locally higher amounts possible along favorable southwestern facing slopes of the Mogollon Rim. Snow levels will remain mainly above 4000 feet today and tomorrow with total 72-hour snow accumulations ranging  from a dusting to 4 inches, but locally higher amounts are possible over the tallest peaks of Northern Arizona. On Wednesday, snow levels will likely drop to 3000-3500 feet which means some higher valley locales could receive a dusting of snow.  Current Conditions As of 11AM MST, visible satellite imagery an...