Area Forecast Discussion
Issued by NWS Tucson, AZ

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493
FXUS65 KTWC 210415
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
915 PM MST Tue Jun 20 2017

.SYNOPSIS...Very hot temperatures will continue across the area
through this weekend with near or record breaking temperatures
forecast. Moisture around the area will bring a chance of
thunderstorms again Wednesday east and south of Tucson, but they
will be more likely to generate gusty outflow winds and lightning
than significant rain. A return to dry weather is forecast
Thursday and Friday.

&&

.DISCUSSION...Basically, we got bit by the "Inverted V" this
afternoon with wind gusts of 50-72 mph out of minor showers while
the decent looking cells well to the east were hard pressed to
exceed 40 mph. Very little instability on our sounding this
evening however the Dcape was an impressive 2124 J/kg. Obviously
good enough for the strong winds we saw.

At this time there are still few thunderstorms continuing this
evening with one weakening complex looking like it might take aim
at the metro area later on. We will see what is left of it by the
time it gets here but likely won`t see much if any lightning but
gusty winds are still a good bet.

We will be left with plenty of cloud cover tonight which will hold
temperatures up and if they linger too long into the morning
hours will hold up convection Wednesday. Overall would expect less
convection Wednesday but strong wind threat will remain from any
convection.

And speaking of heat. Another Tucson record is likely to fall
at midnight (officially). With a low of 87 and a high of 116
today the average temperature for the day is 101.5 or rounded,
102. The previous record was 99 degrees set on June 27th 1990
which makes this Tucson`s first 100 or higher average temperature.

&&

.AVIATION...Valid thru 22/06Z.
Scattered -TSRA/-SHRA ending by 22/09Z. Then isolated to
scattered -TSRA/-SHRA mainly east-to-south of KTUS Wednesday
afternoon. Brief gusts to 45 kts with the strongest TSRA.
Otherwise, scattered clouds 8k-15k ft AGL with broken clouds above
15k ft AGL, and surface wind variable in direction mainly less
than 12 kts away from thunderstorms. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...Convection will slowly taper off into the early
morning hours tonight. Then isolated to scattered thunderstorms
will occur Wednesday afternoon mainly east to south of Tucson.
Thunderstorm outflows will produce brief strong, gusty and erratic
winds once again with the potential for 50+ mph.

Dry conditions will return area-wide Thursday and Friday with
rather gusty west-northwest winds during the afternoon, especially
in the Gila Valley area and around the Frye Fire. Thereafter, a
more favorable pattern for thunderstorm development will return
perhaps as early as Saturday, but more likely Sunday and Monday.
Scattered afternoon and evening thunderstorms should occur Sunday
and Monday, with the greatest coverage of thunderstorms mainly
east to south of Tucson.

&&

.PREV DISCUSSION... /issued 209 PM MST Tue Jun 20 2017/
Despite extensive cloud cover earlier today, Tucson still managed
to crack the 110 degree mark today (high of 111 as of 19Z). Early
afternoon satellite imagery reveals mostly clear skies to the
east of Tucson and it`s entirely conceivable that we could still
climb another 2-3 degrees before the day is over. Meanwhile,
clouds have started to build across the mountains of far eastern
Arizona with a number of showers and thunderstorms already going
across southern New Mexico.

Short term weather concerns are focused on several things, namely
storm chances and the potential for blowing dust. Nearly all
available convective allowing models (and ensembles) indicate
showers and storms developing near Safford and points northeast
through mid afternoon. However they also indicate most of the
activity will be slow moving and dissipate by the time they make
their way into the lower elevations near Tucson. Model MLCAPES drop
off a cliff by the time they would get to Tucson and it would appear
the chance of widespread precip in the deserts is low. Conversely,
this suggests a decent chance of blowing dust between Tucson and
Phoenix across parts of Pima and Pinal Co`s and the Blowing Dust
Advisory will remain in effect until 8 pm this evening.

Convective activity is also possible on Wednesday although the
deeper moisture that we see overhead today should be focused more
along the AZ/NM border tomorrow. PoPs will remain in place in these
areas with slightly lower values in/around Tucson. Drier air will
return on Thursday with noticeably reduced precip chances to close
out the week. This dry air will limit any precip chances to the
mountains through the weekend, but it appears we will see a decent
return of moisture to the entire southeastern portion of AZ by
Monday/Tuesday of next week. Went with well above climo PoPs for
eastern Arizona late in the forecast period.

As for our ongoing heatwave, heat warnings and advisories will
remain in effect unchanged into the weekend. Still a little
uncertain with how bad things will be on Sunday. Parts of the area
will remain close to the 110 degree mark while it appears that
the aforementioned increase in moisture could knock temperatures
back a few degrees across eastern Arizona on Sunday. Will elect to
hold off extending any heat products into Sunday at this time but
it`s certainly a possibility. Fortunately it appears temps will
retreat several degrees next week as dewpoints climb into the
low/mid 50s and take a chunk out of our heating potential.


.CLIMATE...
All time record highs across the region

                     RECORD_DATE AND YEAR
TUCSON INTL AIRPORT  117 6/26/1990
BISBEE-DOUGLAS ARPT  110 6/26/1994
AJO                  117 7/5/2007, 7/6 2007 and 7/31/1995
FORT THOMAS          115 6/26/1990
KITT PEAK             98 7/30/1995
ORGAN PIPE CACTUS    118 7/15/1998, 7/26/1995 and 6/26/1990
PICACHO PEAK         119 7/28/1995
SAFFORD AG STATION   114 6/30/1994
SIERRA VISTA FD      108 7/4/1989
TOMBSTONE            112 7/4/1989
WILLCOX              110 6/28 AND 6/29/1994, 6/26/1990 and 7/6/2005

Daily record highs today through Thursday

DATE                      Jun 20     Jun 21     Jun 22
                          RCD/YR     RCD/YR     RCD/YR
TUCSON INTL AIRPORT      116/2017   112/1990   114/1988
BISBEE-DOUGLAS AIRPORT   108/2017   105/1990   106/1990
AJO                      115/1968   115/1919   115/1960
FORT THOMAS              111/1960   109/2005   112/1961
KITT PEAK                 93/1989    94/1979    92/1988
ORGAN PIPE CACTUS        115/1960   114/1968   113/1955
PICACHO PEAK             112/2008   116/2005   113/1988
SAFFORD AG STATION       111/1989   109/1960   108/1960
SIERRA VISTA FD          103/1989   103/1990   104/2012
TOMBSTONE                105/1990   106/1996   109/1929
WILLCOX                  106/1989   106/1968   106/1990

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 7 PM MST Saturday for AZZ510>514.

Excessive Heat Warning until 7 PM MST Saturday for AZZ501>509-
515.

&&

$$

PUBLIC...Cerniglia
AVIATION....Cerniglia
FIRE WEATHER...Cerniglia

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