Area Forecast Discussion
Issued by NWS Tucson, AZ
FXUS65 KTWC 191550
Area Forecast Discussion
National Weather Service Tucson AZ
850 AM MST TUE JUL 19 2016
.SYNOPSIS...Adequate moisture will provide scattered mainly afternoon
and evening showers and thunderstorms through Wednesday. A slight
decrease in daily coverage of showers and thunderstorms should then
occur Thursday into this weekend. Expect near normal daytime
temperatures Tuesday followed by a pronounced warming trend later
.DISCUSSION...IR/Visible satellite imagery depicted mostly clear
skies to partly cloudy skies at this time. Some of the more
prominent cyclonic twists were moving northwestward just east of
northern Greenlee County, over northwest Sonora, and over east
central Sonora. Water vapor imagery also depicted an inverted trough
over southern New Mexico southward into northern Chihuahua Mexico.
Ample moisture continues across the area with dewpoints at lower
elevations valid 15Z ranging from the mid 50s-mid 60s, and 19/12Z
KTWC sounding total precip water value was 1.50 inches.
There were some differences between the various mesoscale models
regarding the development and evolution of showers/tstms later
today. Instead of a model rehash, the official forecast of scattered
showers/tstms this afternoon/evening appears to be on track. The
main concern this afternoon/evening will be the potential for
locally heavy rainfall and brief strong wind gusts that may approach
There is also a potential for blowing dust along the Interstate 10
corridor northwest of Tucson to Phoenix. Forecast confidence is not
sufficiently high at this time to issue a Blowing Dust Advisory. A
slight chance of showers/tstms continues for much of the area late
tonight. High temps this afternoon will generally be a few degs
warmer versus Monday.
Please refer to the additional sections for further detail.
.AVIATION...VALID THRU 20/18Z.
Isolated showers through the early morning hours. Sct-bkn clouds at
6-9k ft agl and bkn-ovc clouds at 10-14k ft agl. Expect scattered
showers and thunderstorms this afternoon and evening, then tapering
in coverage late tonight. Brief wind gusts of 40-45 kts and MVFR
conditions will occur with the stronger TSRA. Outside of gusty
outflows, surface wind will generally be less than 12 kts through
Wednesday morning. Aviation discussion not updated for TAF
.FIRE WEATHER...Ample moisture will ensure daily chances of mainly
afternoon and evening showers and thunderstorms this week. A slight
decrease in rain chances will occur late in the week into the
weekend along with an increase in daytime temperatures. Outside of
gusty thunderstorm/outflow winds, expect typical diurnal 20-ft wind
patterns each day at mainly less than 15 mph.
.CLIMATE...As the area heats up again, could see a few spots across
the western deserts approach record highs later in the week.
.PREV DISCUSSION /250 AM MST/...Isolated light showers were occurring
early this morning east of Tucson. Expect these to continue thru
sunrise as they move to the WNW. A weak MCV was over SW Graham
county as of 2 am, but shouldn`t be a player today as it continue to
What could be a player later today is the inverted trof currently
over Chihuahua MX. This feature is moving slowly to the NW toward
the area. Hi-res models focusing best activity W of Tucson, with
potential for blowing dust across Pinal county towards Phoenix, and
Cochise county. PW values across the remain above normal for July so
locally heavy rain a threat. Can`t rule out a severe storm or two.
Highs today will be around normal.
Scattered afternoon/evening storms Wednesday with highs slightly
warmer than today.
Starting Thursday and continuing through the upcoming weekend there
will be a gradual decrease in shower and thunderstorm activity as
sub-tropical ridge expands over the southern CONUS. Still hanging on
to enough moisture to keep isolated to scattered storms in the
forecast. Highs temperatures will be above normal through this
period, maxing out on Friday.
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