Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Tucson Arizona
926 am MST Thursday Jul 28 2016
Synopsis...Southeast Arizona has plenty of moisture for
continued mainly afternoon and evening thunderstorms into next week.
Perhaps some decrease in coverage will occur today with a strong
upswing again Friday. Expect hotter than average daytime
temperatures through Thursday followed by moderating temperatures by
early next week.
Update...remnant clouds and isolated showers are tracking
southwestward and away from Arizona this morning. Morning
soundings from around the area indicate a swath of deep moisture
remaining over the southern third of the state. Areas further
north toward Flagstaff are indicating much drier air in the mid-
levels of the atmosphere. Water vapor imagery indicates little in
the way of mid/upper level forcing present over the state this
morning. Strong daytime heating will combine with the abundant
moisture to generate showers and thunderstorms mainly this
afternoon and evening. Without a strong forcing mechanism activity
will be generally terrain driven with storm motion from the
northeast to the southwest. An isolated strong storm with gusty
winds is definitely a possibility. Overall, still believe that
coverage will be less than yesterday. Have updated pops today to
reflect the discussed trends.
Aviation...valid through 29/18z.
VFR conditions throughout today, except for possible MVFR
in/around showers and thunderstorms this afternoon and evening. Isold
to sctd -shra and -tsra will be possible 28/20z thru 29/03z.
Brief wind gusts to 35 mph and MVFR conds psbl with stronger thunderstorms and rain.
Otherwise, sfc wind mainly less than 10 kts. Aviation discussion
not updated for taf amendments.
Fire weather...scattered mainly afternoon and evening thunderstorms
will continue into next week. Afternoon temperatures will remain a
bit warmer than average through Friday, then drop to near or just
slightly below normal by early next week.
Previous discussion... /issued 302 am MST Thursday Jul 28 2016/
Discussion...scattered showers and thunderstorms stretched across
the area from Sells to Tucson and to Lordsburg New Mexico. Some of
the thunderstorms have moved over the same general area today.
However, rain gauges have not really experienced as much rainfall
as suggested by radar. At any rate, the latest hrrr model
supported showers and thunderstorms through at least 11z.
Thereafter, looking at a break in the weather for much of the day.
That said, will indicated a somewhat dry forecast for this
afternoon and evening based on the rain cooled sounding profile.
Latest GFS showed the upper high remaining over southern Nevada
through at least Friday, then shifting it to a position over
northern New Mexico by Monday. The model showed a significant
upswing in rainfall coverage this weekend. At any rate, will keep
similar pop values going in the forecast and delay the cooler
daytime temperatures until Saturday into early next week.
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