Area Forecast Discussion
Issued by NWS Tucson, AZ

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000
FXUS65 KTWC 182227
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
327 PM MST Sun Jun 18 2017

.SYNOPSIS...Very hot temperatures are expected this week, with
several days of near or record breaking temperatures likely. A
modest increase in moisture will bring a chance of thunderstorms,
but they will be more likely to generate gusty outflow winds and
lightning than significant rain.

&&

.DISCUSSION...Today the ridge starts to get serious for the
desert southwest, with the ridge amplifying through the region,
followed by the high center slowly consolidating over Arizona in
the next 48 hours. We`ll see near record highs likely through
Wednesday with an Excessive Heat Warning in effect most of the
week.

As the max heat hits us early to mid week, we will also have to
deal with just enough moisture pushing in from the east for high
based convection, but with such a limited moisture source most
storms will bring more wind and lightning than rain. Watch for
organized gusty outflows, especially Tuesday. The moisture
probably won`t push down too far on the temperatures in general,
but a gusty thunderstorm outflow would act like a frontal boundary
pushing across. Should have plenty of time to get hot hot hot
before any potential clouds or outflows temper things.

The fairly static low energy pattern, with the ridge solid through
the week. It breaks down a little and shifts far enough off to
possible allow deeper moisture in late next weekend or early next
week. Better chance of thunderstorms at that point for the last
week of June.

&&

.AVIATION...Valid thru 20/00Z.
Clear skies through Monday morning. Occasional smoke layers above
10k ft AGL. SCT-BKN clouds especially across the higher terrain of
Graham/Greenlee counties Monday afternoon with isolated -SHRA/-TSRA
possible mainly NE of KSAD. Surface winds W-NW 8-13 kts with gusts
to 20 kts into early this evening, then normal diurnal trends less
than 10 kts through Monday morning. Gusty outflow winds possible
Monday afternoon especially in the Gila River Valley near KSAD.
Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Extreme heat and very dry conditions will occur
much of the week with Excessive Heat Warnings in effect through
Thursday. However, there will be an increase in mainly mid to high
level moisture over the next couple of days. This will first occur
mainly across the White Mountains Monday where the moisture combined
with strong surface heating will likely result in dry-lightning
along with gusty and erratic winds. LAL 6 conditions are expected
across the White Mountains Monday and then across the remaining sky
islands of zones 151, 152 and 153 Tuesday and perhaps Wednesday
afternoon as well. The best chance for some wetting rains with the
strongest storms will be Tuesday. Strong and erratic outflow winds
are likely near any thunderstorms that develop.

20-ft winds this week will be typical for June, with light drainage
overnight and westerly to northwesterly 5-15 mph each afternoon.
Minimum RH values will be in the low mid to high single digits
across the lower elevations to the teens in the sky islands. High
levels of instability with Haines 6 conditions are expected Monday,
then generally Haines 5 and 6 for the rest of the forecast period.
Monday through Wednesday afternoons, the atmosphere will be well
mixed and unstable up through 500 mb or 18,000 ft msl.

&&

.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 forecast highs and record highs Monday through Wednesday

                     Jun 19           Jun 20           Jun 21
                     FCST RCD/YR      FCST RCD/YR      FCST RCD/YR
TUCSON INTL AIRPORT  114 115/2016     115 112/2015     115 112/1990
BISBEE-DOUGLAS ARPT  106 108/1959     107 106/1960     108 105/1990
AJO                  115 114/1968     117 115/1968     115 115/1919
FORT THOMAS          112 115/1960     115 111/1960     116 109/2005
KITT PEAK             99  95/1989     100  93/1989     100  94/1979
ORGAN PIPE CACTUS    115 115/1960     117 115/1960     113 114/1989
PICACHO PEAK         115 111/2002     117 112/2008     117 116/2005
SAFFORD AG STATION   112 109/1989     114 111/1989     115 109/1960
SIERRA VISTA FD      106 106/1989     106 103/1989     107 103/1990
TOMBSTONE            107 108/1989     108 105/1980     109 106/1996
WILLCOX              105 108/1989     106 105/1990     107 106/1968

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 11 AM Monday to 7 PM MST Thursday for
AZZ510>514.

Excessive Heat Warning until 7 PM MST Thursday for AZZ501>506-
509.

Excessive Heat Warning from 11 AM Monday to 7 PM MST Thursday
for AZZ507-508-515.

&&

$$

Meyer/Lader

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