Area Forecast Discussion
Issued by NWS Tucson, AZ
FXUS65 KTWC 211545
Area Forecast Discussion
National Weather Service Tucson AZ
845 AM MST THU JUL 21 2016
.SYNOPSIS...A decrease in thunderstorms activity will occur over
the next several days as the air mass over the region dries out.
As a result temperatures will climb to roughly 10 degrees warmer
than average Friday and Saturday with record high temperatures
possible both days. Monsoon moisture will then gradually return
Sunday onward for an overall increase in convection and a slight
cooling of afternoon temperatures.
.DISCUSSION...Drying has not started yet in any significant fashion
thus we still have nearly 1.5" PW on the morning sounding with a
little less to the east. Also the sounding has a slightly better
thermal profile compared to yesterday with a touch of cooling aloft
an warming below. The upshot, the atmosphere is ready with plenty of
sunshine to help out. Not much if anything noticeable out there to
help focus or provide extra lift so this will primarily be another
diurnal, terrain driven day much like yesterday. The latest runs of
the HRRR and UA WRF NAM agree so would expect convection to begin to
develop 18-19z over the higher terrain to the south and southeast
then move to the NNW through the day, much like yesterday.
More noticeable drying to take place from the east tomorrow and
Saturday and that is apparent on this mornings water vapor imagery.
This should provide for a reduction in the convection across the
area while also lifting afternoon temperatures to roughly 10 degrees
warmer than average, which means hot but not quite heat advisory
hot. That said we will likely see a few record highs fall over the
next few days.
The moisture will begin to return to the region later Sunday into
next week which will enhance the convection threat and put us back
into a somewhat active pattern once again. Thankfully the extra
clouds and scattered showers will trim a few degrees of the high
temperatures next week. Cerniglia
.AVIATION...VALID THRU 22/18.
Sct-bkn clouds at 6-9k ft agl and bkn-ovc clouds at 10-15k ft agl
developing with isolated to scattered showers and T-storms today
into this evening. Once again, heavy rainfall, gusty winds, and some
areas of blowing dust will be the biggest concerns. The showers and
storms will diminish aft 22/04Z. Aviation discussion not updated for
.FIRE WEATHER...Moisture in place will lead to the showers and
thunderstorms again today, developing after 11 am over higher
terrain and drifting to the north. A drying trend will then lead to
reduced coverage of showers and thunderstorms Friday into this
weekend. Moisture will increase again early next week resulting in
an uptick in convection. Outside of gusty thunderstorm outflows, 20-
foot winds will be terrain driven and mostly less than 15 mph.
.CLIMATE...Record high temperatures will be approached at a few spots
today then most of the area will be at or near record highs Friday
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