Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/27/16
Area Forecast Discussion
National Weather Service Flagstaff AZ
857 PM MST SUN JUN 26 2016
.SYNOPSIS...On Monday, expect scattered showers and thunderstorms,
primarily along and south of the Mogollon Rim. Strong, gusty
winds are possible near any storms. Beginning Tuesday, monsoonal
moisture is forecast to spread across all of northern Arizona
leading to daily chances for showers and thunderstorms through the
week.
&&
.DISCUSSION...
Only isolated and generally light showers are expected to continue
this evening and overnight. Additional storm development is likely
by late Monday morning.
&&
.PREV DISCUSSION /406 PM MST/...So far today, shower and
thunderstorm activity has generally occurred along and south of
a line from Window Rock to Heber-Overgaard. This area will likely
continue to be the focus for shower activity today, although some
showers may expand westward a bit to include Payson and Clints
Well this afternoon and evening.
On Monday, increasing moisture is forecast along and south of the
Mogollon Rim. This will lead to better chances for showers and
thunderstorms there. These storms will once again be high based,
so strong outflow winds will be the primary hazard.
Beginning Tuesday, high pressure in place near the Four Corners is
forecast to lead to an active monsoon pattern. A moist easterly
flow will transition to a moist southerly wind around the middle
of the week. This will draw deeper moisture into the region
leading to increasing chances for showers and thunderstorms across
all of northern Arizona. This moisture is expected to remain in
place over the following days causing daily chances for showers
and thunderstorms through the remainder of the week.
&&
.AVIATION...For the 06Z Package...Isolated to scattered showers
and thunderstorms expect to develop mainly southeast of a KFLG-
KRQE line after 18Z Monday. Otherwise, expect VFR conditions.
Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Expect deeper moisture with increasing coverage in
showers and thunderstorms Monday and Tuesday. Storm motion
Monday will generally be from southeast to northwest and south to
north on Tuesday. Expect erratic and gusty winds near any showers
and storms.
Wednesday through Friday...An active wet Monsoon weather pattern
is expected with numerous showers and thunderstorms each day
across northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...KD/RR
AVIATION...KD
FIRE WEATHER...MAS
For Northern Arizona weather information visit
weather.gov/flagstaff
[top]
Area Forecast Discussion
National Weather Service Phoenix AZ
730 PM MST SUN JUN 26 2016
.SYNOPSIS...
High pressure will move somewhat north and east of Arizona this week
allowing warm temperatures to prevail, but also bring a couple of
weather disturbances through the state. An increase in monsoon
moisture will accompany these weather systems providing a threat of
afternoon and evening showers and thunderstorms the remainder of
week.
&&
.DISCUSSION...
A well defined circulation center was quite evident in WV imagery
across far northern Sonora this evening with stronger ascent and
upper divergent signatures analyzed throughout SE AZ. 00Z KTWC
sampled rather modest Sfc-H7 8 g/kg mixing ratios, however deep
layer moisture flux has advected more favorable 10-11 g/kg profiles
northward per objective analysis. Given the general UVV and weakly
capped MLCapes around 500 J/kg, more robust convection has developed
along the I-19 corridor. Closer towards central AZ, reduced daytime
insolation and lower moisture values (closer to 7 g/kg mixing
ratios) have yielded negligible instability despite relatively steep
midlevel lapse rates. Thus, while virga/sprinkles/very light showers
may be possible around the Phoenix metro, convection moving north
may meet a fate of dissipation. Will continue to monitor trends
through the evening, and would be most concerned about stronger
outflows and dust production versus actual storms.
One area of somewhat more concern may be through SW AZ where some
more palpable instability has been analyzed, and
vorticity/divergence fields will translate during the overnight.
Several deterministic models and ensemble means suggest midlevel
moisture lifted towards a steeper lapse rate environment while low
level T/Td spreads narrow. There was enough evidence presented in
models and analysis to increase pops and mention showers through the
SW parts of the CWA later tonight. Otherwise, made some substantial
changes to hourly temperatures based on current trends which were
much cooler than previously advertised.
&&
.PREVIOUS DISCUSSION...
/240 PM MST SUN JUN 26 2016/
Monday through Saturday...
The forecast becomes very complicated this week with respect to
shower/thunderstorm potential, coverage, and intensity - mainly
across portions of southwest and south central AZ. In other words,
can we call it quasi-unsettled this week?
We know the monsoon moisture boundary arrived in southeast AZ the
past couple of days, and is forecast to spread west and north across
the remainder of southern and central AZ this week. And normally
this time of year once the moistures in place it should be like
clockwork, i.e., first afternoon mountain thunderstorms, then by
evening drifting toward the desert edge including developing on
convective outflows and/or outflow collisions. Not this week, there
is too much going on in the mid and upper atmosphere.
For example, the last vestiges of the northwest Mexico inverted trof
will move into the region Monday afternoon. More cyclonic flow over
southern CA will aid in a threat of thunderstorms over the Joshua
Tree National Park mountains, while difluent flow aloft in southwest
and south central AZ generates convective potential as well. But a
caveat, extensive mid/high clouds associated with the inverted trof
axis may cut down on afternoon heating and the convective potential
in the south central AZ Monday.
And for Tuesday and Tuesday night, while 300/250 mb flows become
southwesterly, a developing 500 mb easterly flow advects a weak mid
level disturbance from New Mexico into southeast and south Central
AZ late Tuesday afternoon and night. 500 mb disturbances usually
spark overnight convection under very moist conditions.
Therefore there is much uncertainty, and we can go on and on for
Wednesday through Saturday. Therefore, the best approach is to call
is quasi-unsettled, or a broad brush approach to shower/thunderstorm
potential since 1) the monsoon moisture will be in place, and 2)
models will no doubt have trouble forecasting any minor
perturbations in this developing convoluted flow aloft.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Low confidence forecast through Monday afternoon as wind
direction/shifts will be dictated by outflow boundaries traveling
from storms more removed from terminal sites. Southwest winds this
evening will shift to an easterly direction earlier than typical due
to outflow propagating from eastern AZ, but timing is very
uncertain. Cigs 12K-15K ft and occasional virga will be common
through Monday morning.
Much better chances for stronger east/northeast outflow winds will
arrive later Monday afternoon. Actual storms may not survive to
lower elevations, though mountain obscuration, blowing dust, and
frequent lightning for arrivals/departures to the east may be
problematic.
Southeast California/Southwest Arizona including KIPL and KBLH:
Cigs in a 10K-15K ft will increase through Monday with occasional
virga, and possibly a few showers reaching the ground at KIPL. While
a south to southeast sfc wind will be preferred, periods of
variability will be common Monday morning (especially around
showers). A few stronger gusts may also be possible for brief
periods. Forecast confidence is only moderate.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday...
Temperatures will continue to "cool" with highs on Wednesday around
105-112F dropping into the 100-110F range by Sunday. As monsoon
moisture levels continue to increase over the region, isolated
thunderstorms are possible each afternoon/evening over much of the
desert southwest, with the highest chances over the higher terrain
of central and eastern Arizona. Accompanying any storm that develops
will be wetting rains, gusty erratic winds, and lightning. This
increase in moisture will support a rise in minimum humidities, with
values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...MO/Vasquez
AVIATION...MO
FIRE WEATHER...Hernandez
Area Forecast Discussion
National Weather Service Phoenix AZ
730 PM MST SUN JUN 26 2016
.SYNOPSIS...
High pressure will move somewhat north and east of Arizona this week
allowing warm temperatures to prevail, but also bring a couple of
weather disturbances through the state. An increase in monsoon
moisture will accompany these weather systems providing a threat of
afternoon and evening showers and thunderstorms the remainder of
week.
&&
.DISCUSSION...
A well defined circulation center was quite evident in WV imagery
across far northern Sonora this evening with stronger ascent and
upper divergent signatures analyzed throughout SE AZ. 00Z KTWC
sampled rather modest Sfc-H7 8 g/kg mixing ratios, however deep
layer moisture flux has advected more favorable 10-11 g/kg profiles
northward per objective analysis. Given the general UVV and weakly
capped MLCapes around 500 J/kg, more robust convection has developed
along the I-19 corridor. Closer towards central AZ, reduced daytime
insolation and lower moisture values (closer to 7 g/kg mixing
ratios) have yielded negligible instability despite relatively steep
midlevel lapse rates. Thus, while virga/sprinkles/very light showers
may be possible around the Phoenix metro, convection moving north
may meet a fate of dissipation. Will continue to monitor trends
through the evening, and would be most concerned about stronger
outflows and dust production versus actual storms.
One area of somewhat more concern may be through SW AZ where some
more palpable instability has been analyzed, and
vorticity/divergence fields will translate during the overnight.
Several deterministic models and ensemble means suggest midlevel
moisture lifted towards a steeper lapse rate environment while low
level T/Td spreads narrow. There was enough evidence presented in
models and analysis to increase pops and mention showers through the
SW parts of the CWA later tonight. Otherwise, made some substantial
changes to hourly temperatures based on current trends which were
much cooler than previously advertised.
&&
.PREVIOUS DISCUSSION...
/240 PM MST SUN JUN 26 2016/
Monday through Saturday...
The forecast becomes very complicated this week with respect to
shower/thunderstorm potential, coverage, and intensity - mainly
across portions of southwest and south central AZ. In other words,
can we call it quasi-unsettled this week?
We know the monsoon moisture boundary arrived in southeast AZ the
past couple of days, and is forecast to spread west and north across
the remainder of southern and central AZ this week. And normally
this time of year once the moistures in place it should be like
clockwork, i.e., first afternoon mountain thunderstorms, then by
evening drifting toward the desert edge including developing on
convective outflows and/or outflow collisions. Not this week, there
is too much going on in the mid and upper atmosphere.
For example, the last vestiges of the northwest Mexico inverted trof
will move into the region Monday afternoon. More cyclonic flow over
southern CA will aid in a threat of thunderstorms over the Joshua
Tree National Park mountains, while difluent flow aloft in southwest
and south central AZ generates convective potential as well. But a
caveat, extensive mid/high clouds associated with the inverted trof
axis may cut down on afternoon heating and the convective potential
in the south central AZ Monday.
And for Tuesday and Tuesday night, while 300/250 mb flows become
southwesterly, a developing 500 mb easterly flow advects a weak mid
level disturbance from New Mexico into southeast and south Central
AZ late Tuesday afternoon and night. 500 mb disturbances usually
spark overnight convection under very moist conditions.
Therefore there is much uncertainty, and we can go on and on for
Wednesday through Saturday. Therefore, the best approach is to call
is quasi-unsettled, or a broad brush approach to shower/thunderstorm
potential since 1) the monsoon moisture will be in place, and 2)
models will no doubt have trouble forecasting any minor
perturbations in this developing convoluted flow aloft.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Low confidence forecast through Monday afternoon as wind
direction/shifts will be dictated by outflow boundaries traveling
from storms more removed from terminal sites. Southwest winds this
evening will shift to an easterly direction earlier than typical due
to outflow propagating from eastern AZ, but timing is very
uncertain. Cigs 12K-15K ft and occasional virga will be common
through Monday morning.
Much better chances for stronger east/northeast outflow winds will
arrive later Monday afternoon. Actual storms may not survive to
lower elevations, though mountain obscuration, blowing dust, and
frequent lightning for arrivals/departures to the east may be
problematic.
Southeast California/Southwest Arizona including KIPL and KBLH:
Cigs in a 10K-15K ft will increase through Monday with occasional
virga, and possibly a few showers reaching the ground at KIPL. While
a south to southeast sfc wind will be preferred, periods of
variability will be common Monday morning (especially around
showers). A few stronger gusts may also be possible for brief
periods. Forecast confidence is only moderate.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday...
Temperatures will continue to "cool" with highs on Wednesday around
105-112F dropping into the 100-110F range by Sunday. As monsoon
moisture levels continue to increase over the region, isolated
thunderstorms are possible each afternoon/evening over much of the
desert southwest, with the highest chances over the higher terrain
of central and eastern Arizona. Accompanying any storm that develops
will be wetting rains, gusty erratic winds, and lightning. This
increase in moisture will support a rise in minimum humidities, with
values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...MO/Vasquez
AVIATION...MO
FIRE WEATHER...Hernandez
Area Forecast Discussion
National Weather Service Flagstaff AZ
406 PM MST SUN JUN 26 2016
.SYNOPSIS...On Monday, there will be enough moisture in place
over central and eastern Arizona to cause scattered showers and
thunderstorms, primarily along and south of the Mogollon Rim.
Strong, gusty winds are possible near any storms. Beginning
Tuesday, monsoonal moisture is forecast to spread across all of
northern Arizona leading to daily chances for showers and
thunderstorms through the week.
&&
.DISCUSSION...So far today, shower and thunderstorm activity has
generally occurred along and south of a line from Window Rock to
Heber-Overgaard. This area will likely continue to be the focus
for shower activity today, although some showers may expand
westward a bit to include Payson and Clints Well this afternoon
and evening.
On Monday, increasing moisture is forecast along and south of the
Mogollon Rim. This will lead to better chances for showers and
thunderstorms there. These storms will once again be high based,
so strong outflow winds will be the primary hazard.
Beginning Tuesday, high pressure in place near the Four Corners
is forecast to lead to an active monsoon pattern. A moist
easterly flow will transition to a moist southerly wind around
the middle of the week. This will draw deeper moisture into the
region leading to increasing chances for showers and thunderstorms
across all of northern Arizona. This moisture is expected to
remain in place over the following days causing daily chances for
showers and thunderstorms through the remainder of the week.
&&
.AVIATION...For the 00Z Package...Isolated to scattered showers and
thunderstorms with possible wind gusts to 40kts from KFLG-KRQE
southeast until around 02z. Storms will be possible after 17Z over
all of northern Arizona. Otherwise, expect VFR conditions. Aviation
discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Expect deeper moisture with increasing coverage in
showers and thunderstorms Monday and Tuesday. Storm motion Monday
will generally be from southeast to northwest and south to north on
Tuesday. Expect erratic and gusty winds near any showers and storms.
Wednesday through Friday...An active, wet Monsoon weather pattern
is expected with numerous showers and thunderstorms each day
across northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...RR
AVIATION...MAS
FIRE WEATHER...MAS
For Northern Arizona weather information visit
weather.gov/flagstaff
[top]
Area Forecast Discussion
National Weather Service Tucson AZ
336 PM MST SUN JUN 26 2016
.SYNOPSIS...Plenty of moisture around this week with an increasing
chance of mainly afternoon and evening showers and thunders across
Southeast Arizona.
&&
DISCUSSION...Convection is finally firing over expected areas,
including areas southeast through southwest of Tucson as well as
the east central mountains (northern Graham and Greenlee
counties). We had a delays in initiation due to morning cloud
cover as well as a bit more convective inhibition to overcome as
per the KTWC morning sounding.
So the strong outflow from the southern Mogollon Rim is just now
pushing southwest into valley locations of Graham county, and it
doesn`t really look as strong as the increasing mid level easterly
flow suggested earlier. Development across southern areas is
increasing, but not anything to write home about either. We may
still have some mid level CAPE for an outflow to tap into later
this evening, so more debris to contend with early Monday morning.
Weak subsidence behind a minor mid level feature shifting north of
the area will probably limit thunderstorms to mainly mountain
areas Monday.
A deeper and stronger fetch around high pressure reconsolidating
to our east should push our thunderstorm coverage up as we
reinforce available moisture and draw in weak inflections around
the high.
&&
AVIATION...VALID THRU 28/00Z.
Isolated to scattered -TSRA/-SHRA. The best timing for TSRA is
mostly from 20Z this afternoon until 27/08Z this evening. Brief
wind gusts to near 40 kts and MVFR conditions due to reduced
visibilities will be possible with the stronger TSRA. Isolated
-SHRA/-TSRA will be possible area-wide late tonight into early
Monday afternoon. Otherwise, cloud decks generally ranging from
10k- 15k ft MSL, and surface wind terrain driven mainly less than
12 kts. Aviation discussion not updated for TAF amendments.
&&
FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this afternoon and evening. Greater coverage of
showers and thunderstorms should then occur Monday through next
Saturday. Otherwise, daytime minimum relative humidity values will
generally range from the mid teens to around 30 percent with fair
to good nighttime recovery. 20-foot winds into Monday as well as
Thursday through Saturday will be terrain driven at less than 15
mph. 20-foot winds Tuesday and Wednesday will generally be from
the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds
Tuesday and Wednesday should prevail from shortly after sunrise
into the early afternoon hours.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Meyer/Rasmussen
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Tucson AZ
336 PM MST SUN JUN 26 2016
.SYNOPSIS...Plenty of moisture around this week with an increasing
chance of mainly afternoon and evening showers and thunders across
Southeast Arizona.
&&
DISCUSSION...Convection is finally firing over expected areas,
including areas southeast through southwest of Tucson as well as
the east central mountains (northern Graham and Greenlee
counties). We had a delays in initiation due to morning cloud
cover as well as a bit more convective inhibition to overcome as
per the KTWC morning sounding.
So the strong outflow from the southern Mogollon Rim is just now
pushing southwest into valley locations of Graham county, and it
doesn`t really look as strong as the increasing mid level easterly
flow suggested earlier. Development across southern areas is
increasing, but not anything to write home about either. We may
still have some mid level CAPE for an outflow to tap into later
this evening, so more debris to contend with early Monday morning.
Weak subsidence behind a minor mid level feature shifting north of
the area will probably limit thunderstorms to mainly mountain
areas Monday.
A deeper and stronger fetch around high pressure reconsolidating
to our east should push our thunderstorm coverage up as we
reinforce available moisture and draw in weak inflections around
the high.
&&
AVIATION...VALID THRU 28/00Z.
Isolated to scattered -TSRA/-SHRA. The best timing for TSRA is
mostly from 20Z this afternoon until 27/08Z this evening. Brief
wind gusts to near 40 kts and MVFR conditions due to reduced
visibilities will be possible with the stronger TSRA. Isolated
-SHRA/-TSRA will be possible area-wide late tonight into early
Monday afternoon. Otherwise, cloud decks generally ranging from
10k- 15k ft MSL, and surface wind terrain driven mainly less than
12 kts. Aviation discussion not updated for TAF amendments.
&&
FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this afternoon and evening. Greater coverage of
showers and thunderstorms should then occur Monday through next
Saturday. Otherwise, daytime minimum relative humidity values will
generally range from the mid teens to around 30 percent with fair
to good nighttime recovery. 20-foot winds into Monday as well as
Thursday through Saturday will be terrain driven at less than 15
mph. 20-foot winds Tuesday and Wednesday will generally be from
the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds
Tuesday and Wednesday should prevail from shortly after sunrise
into the early afternoon hours.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Meyer/Rasmussen
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Phoenix AZ
240 PM SUN JUN 26 2016
.SYNOPSIS...
A very warm air mass will keep temperatures above normal through at
least the first half of the week. A increase in monsoon moisture is
also expected, and will provide a slight threat of afternoon and
evening showers and thunderstorms the remainder of week.
&&
.DISCUSSION...
Tonight...
The inverted trof so noticeable on vapor imagery just south of the
AZ border developed an west-east deformation/stretching zone replete
with considerable mid/high level cloudiness. Cloudiness was able to
retard the heating curve and defer any precip to virga or light
showers with the dense clouds. More is expected overnight. However
there are a few afternoon thunderstorms in the less cloudy areas of
the White Mountains, just west of Nogales along the Mexican border,
and in far southeast AZ at 2 pm mst.
Monday through Saturday
The forecast becomes very complicated this week with respect to
shower/thunderstorm potential, coverage, and intensity, mainly
across portions of southwest and south central AZ. In other words,
can we call it quasi-unsettled this week?
We know the monsoon moisture boundary arrived in southeast AZ the
past couple of days, and is forecast to spread west and north across
the remainder of southern and central AZ this week. And, normally
this time of year once the moistures in place it should be like
clock-work right, i.e., first afternoon mountain thunderstorms then
by evening drifting toward the desert edge, including developing on
convective outflows and/or outflow collisions. Not this week, there
is too much going on in the mid and upper atmosphere.
For example, the last vestiges of the northwest Mexico inverted trof
will move into the region Monday afternoon. More cyclonicity over
southern CA will develop a threat of thunderstorms over the Joshua
Tree National Park mountains, while difluent flow aloft in southwest
and south central AZ generates convective potential as well. But a
caveat, extensive mid/high clouds associated with the inverted trof
axis may cut down on afternoon heating and the convective potential
in the south central AZ Monday.
And for Tuesday and Tuesday night, while 300/250 mb flows become
southwesterly, a developing 500 mb easterly flow advects a weak mid
level disturbance from New Mexico into southeast and south Central
AZ late Tuesday afternoon and night. 500 mb disturbances usually
spark overnight convection under very moist conditions.
Therefore there is much uncertainty, and we can go on and on for
Wednesday through Saturday. Therefore the best approach is to call
is quasi-unsettled, or a broad brush approach to shower/thunderstorm
potential since 1) the monsoon moisture will be in place, and 2)
models will no doubt have trouble forecasting any minor
perturbations in this developing convoluted flow aloft.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Showers moving in from the southeast have caused winds to shift to a
southeasterly direction this afternoon over Phoenix terminals. With
more activity in southeast AZ still propagating to the northwest,
anticipate that these southeasterly winds will stick around for
another hour or so before shifting temporarily back to the west
around 22Z. Speeds will remain around 10 kts, however cannot rule
out gusty erratic winds and blowing dust from distant south and east
AZ storms for the remainder of the day at Phoenix terminals.
However, low confidence in exact spatial and temporal coverage
precludes mention in 18Z TAF. Broken to overcast mid to high clouds
aoa 10kft will continue to advect into the region for the remainder
of the day before decreasing in coverage early tomorrow morning.
Southeast California/Southwest Arizona including KIPL and KBLH:
Skies will remain mostly clear with a few passing high clouds around
15-20 kft. Winds will remain out of the south at KBLH and out of the
southeast at KIPL, with speeds generally around 10-15 kts
accompanied by a few afternoon gusts up to 20 to 25 kts.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday...
Temperatures will continue to "cool," with highs on Wednesday around
105-112F dropping into the 100-110F range by Sunday.
As monsoon moisture levels continue to increase over the region,
isolated thunderstorms are possible each afternoon/evening over much
of the desert southwest, with the highest chances over the higher
terrain of central and eastern Arizona. Accompanying any storm that
develops will be wetting rains, gusty erratic winds, and lightning.
This increase in moisture will support a rise in minimum humidities,
with values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Vasquez
AVIATION...Hernandez
FIRE WEATHER...Hernandez
Area Forecast Discussion
National Weather Service Flagstaff AZ
940 AM MST SUN JUN 26 2016
.SYNOPSIS...Dry and hot weather will persist across far western
Arizona today. Mid level moisture will remain over central and
eastern Arizona through Monday, and bring widely scattered showers
and thunderstorms. Strong, gusty winds are possible near any
storms. Monsoonal moisture to increase and spread across northern
Arizona on Tuesday, with increasing daytime shower and
thunderstorm activity lasting through the week.
&&
.DISCUSSION...For today, the highest moisture and best chances
for showers and thunderstorms will be along and south of the White
Mountains and the eastern Mogollon Rim. Elsewhere, drier air and
more stable conditions will limit convective activity. Slight
chances for showers are forecast along the western Mogollon Rim,
including the city of Flagstaff. This seems reasonable as an
extensive cumulus field is expected to develop with heating. As
highlighted in the previous forecast discussion, today`s storms
will once again be high-based leading to the potential for strong
outflows from collapsing storms.
In terms of forecast updates, the current forecast appears to be
on track and no short term updates are anticipated at this time.
&&
.PREV DISCUSSION /303 AM MST/... Northern Arizona will be slowly
transitioning to a monsoon thunderstorm pattern over the next two
days. Strong and gusty outflow winds should be expected near any
storms or virga. The Flagstaff airport did have 2 periods of
outflow wind gusts to 48 and 47 mph yesterday, an indication of
outflow speeds possible through Monday afternoon.
Satellite imagery this morning shows the monsoonal moisture plume
running from NW Mexico through Tucson then northeastward through
New Mexico. Satellite derived pw values are up to near 1.5 inches
around Tuscon this morning. Models remain consistent in showing
mid level easterly flow increasing across central and southern AZ
today and this will allow moisture to slowly increase across areas
along and south of I-40 through Monday. Areas along the Utah
border to remain hot and nearly cloud free today as this area is
under the high pressure circulation center.
Starting Tuesday, models are in good agreement with moist easterly
flow through Wednesday morning becoming light southerly through
Wednesday. Monsoonal moisture to remain overhead through the week
and daytime precip chances were nudged upward a few points along
the Mogollon Rim. Max temps to cool to near normal for dates
starting Wednesday.
&&
.AVIATION...For the 18Z Package...Isolated to scattered showers and
thunderstorms with possible gusts to 40kts will redevelop from KFLG-
KRQE southeast this afternoon and evening until around 02z.
Otherwise, expect VFR conditions. Aviation discussion not updated
for TAF amendments.
&&
.FIRE WEATHER...Monsoon moisture will slowly increase northward each
day. Expect deeper moisture with increasing coverage in showers and
thunderstorms starting on Monday. Storm motion today and Monday will
generally be from northeast to southwest. Expect erratic and gusty
winds near any showers and storms.
Tuesday through Thursday...An active wet Monsoon weather pattern is
forecast with good shower and thunderstorm coverage each day across
northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...RR/DL
AVIATION...MAS
FIRE WEATHER...MCS
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Tucson AZ
940 AM MST SUN JUN 26 2016
.SYNOPSIS...We now have enough moisture for isolated to scattered
showers and thunderstorms this weekend. A more favorable flow
regime will then provide increased coverage of showers and
thunderstorms Monday through next Saturday.
&&
.DISCUSSION...Still plenty of debris cloud this morning with
embedded light showers. This is going to slow the heating a bit
with initial clearing underway in portions of Cochise and Santa
Cruz counties. The 12Z KTWC sounding still has plenty of moisture
at 1.4 inches precipitable water. The mid level easterly flow has
already increased substantially accompanied by an increase in
shear that should help to organize outflow activity this
afternoon. The direction favors strong outflow off the Mogollon
Rim through Graham county.
Latest HRRR trends push 2 strong outflows westward, including the
Rim shot and a second outflow from activity in Cochise county
pushing west and northwestward. The 12z UofA WRF-NAM paints a
similar scenario with the outflow from the Cochise county activity
pushing through the Tucson Metro area around mid to late
afternoon. Minor adjustments to increase activity in the east
central mountains and subsequent outflow westward, otherwise we
have solid forecast trends. Please see the previous discussion
below for additional details.
&&
.AVIATION...VALID THRU 27/18Z.
Isolated to scattered -TSRA/-SHRA. The best timing for TSRA at
the KTUS/KOLS/KDUG terminals is mostly from 20Z this afternoon
until 27/02Z this evening. Brief wind gusts to near 40 kts and
MVFR conditions due to reduced visibilities will be possible with
the stronger TSRA. Isolated -SHRA/-TSRA will be possible area-wide
late tonight into early Monday morning. Otherwise, cloud decks
generally ranging from 10k- 15k ft MSL, and surface wind terrain
driven mainly less than 12 kts. Aviation discussion not updated
for TAF amendments.
&&
.FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this afternoon and evening. Greater coverage of
showers and thunderstorms should then occur Monday through next
Saturday. Otherwise, daytime minimum relative humidity values will
generally range from the mid teens to around 30 percent with fair
to good nighttime recovery. 20-foot winds into Monday as well as
Thursday through Saturday will be terrain driven at less than 15
mph. 20-foot winds Tuesday and Wednesday will generally be from
the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds
Tuesday and Wednesday should prevail from shortly after sunrise
into the early afternoon hours.
&&
.PREV DISCUSSION...The hi-res models suggest a scenario late
tonight similar to that presently occurring across the area. In
other words, a fairly widespread convective debris cloud cover
with patches of sprinkles or light rain.
26/00Z GFS/ECMWF/CMC remained fairly similar regarding the synoptic
scale pattern regime over the southwestern states starting Monday
and continuing into early next weekend. Strong high pressure aloft
Monday is progged to become centered over southern Utah. The GFS/
ECMWF depict an inverted trough to move into southwestern AZ from
the northern Gulf of California Monday.
Quick glance at the U/A WRF-NAM suggests that showers/tstms Monday
afternoon would only be confined to the White Mountains and near the
international border adjacent Santa Cruz/southern Pima County. Thus,
there is the potential that Monday may be a "down day" perhaps due
to subsidence on the eastern periphery of the aforementioned
inverted trough. Forecast confidence in this particular detail is
somewhat low, however. Thus, for this forecast package, have
continued with scattered showers/tstms mainly from Tucson
eastward/southward.
Thereafter, not much daily variation in shower/tstm coverage is
anticipated Tuesday into next Saturday. The deterministic GFS/ECMWF/
CMC were similar with maintaining fairly ample moisture across this
forecast area. These solutions were similar with the continuation of
a light ely/sely mid-level flow regime thru about Wednesday. The mid-
level flow regime is then progged to become more wly/swly especially
from Tucson westward starting Thursday and continuing into next
Saturday. This subtle change may be sufficient for at least a slight
downward trend in shower/tstm coverage, especially across western
sections. Again, forecast confidence is fairly low at this time in
stating that a definitive downward precip trend anywhere in the area
is in the offing late this week.
High temps for the Tucson metro area and locales west-to-northwest
of Tucson will be near normal during much of this forecast period.
However, daytime temps for locales east-to-south of Tucson, such as
Safford, Douglas and Nogales will average a few degs below normal
this week.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Meyer/Francis
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Tucson AZ
915 PM MST SUN JUN 26 2016
.SYNOPSIS...Plenty of moisture around this week with an increasing
chance of mainly afternoon and evening showers and thunders across
Southeast Arizona.
&&
.DISCUSSION...Earlier this afternoon and evening showers and
thunderstorms developed generally from extreme southeastern Pima
county and across eastern Santa Cruz county. These showers and
storms then moved rapidly northwest across parts of the Tucson metro
where they caused damage, with power lines and trees down earlier
this evening, mainly in the area from 1st Ave to Campbell Ave and
from River to Prince. In addition, moderate to heavy rainfall
occurred in this same general area, with amounts ranging from around
0.50 -0.80 inches, with only an isolated report above 1.25 inches.
The Tucson Intl Airport reported a total of 0.11 inches so far for
the day.
Radar mosaic from around the region is detecting a batch of light
rain that extends across much of northeast Pima county and further
to the southeast into extreme eastern Santa Cruz county and
southwest Cochise county. All of this activity will continue to
march to the northwest during the remainder of the evening and will
diminish in the process. The inherited POP forecast for the rest of
tonight is still in good shape, so no changes are planned at this
time. However, will continue to monitor satellite and radar trends
and will make adjustments if warranted.
As of 04Z (9 PM MST), temperatures across the region ranged from the
upper 60s to the mid 80s, with the Tucson Intl Airport reporting a
temp of 80 degs, after reaching an afternoon high temp of 102 degs,
which was exactly normal for this date. The rainfall resulted in
cooling temperatures in several locations, especially for the Tucson
metro, so will make some adjustments to the short term hourly
temperature grids to reflect the most recent trends.
For details beyond tonight, please refer to the previous discussion
below.
&&
.AVIATION...VALID THRU 28/06Z.
Isolated to scattered -TSRA/-SHRA. The best timing for -TSRA/-SHRA
is mostly until around 27/08Z. Isolated -SHRA/-TSRA will still be
possible area-wide late tonight into early Monday afternoon.
Otherwise, cloud decks generally ranging from 10k-15K FT MSL, and
surface wind terrain driven mainly less than 12 kts. Aviation
discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Isolated showers and thunderstorms will remain
possible through the rest of this evening and overnight. Greater
coverage of showers and thunderstorms should then occur Monday
through next Saturday. Otherwise, daytime minimum relative humidity
values will generally range from the mid teens to around 30 percent
with fair to good nighttime recovery. 20-foot winds into Monday as
well as Thursday through Saturday will be terrain driven at less
than 15 mph. 20-foot winds Tuesday and Wednesday will generally be
from the east at 5-15 mph with gusts of 15-20 mph. The strongest
speeds Tuesday and Wednesday should prevail from shortly after
sunrise into the early afternoon hours.
&&
.PREV DISCUSSION...Weak subsidence behind a minor mid level feature
shifting north of the area will probably limit thunderstorms to
mainly mountain areas Monday.
A deeper and stronger fetch around high pressure reconsolidating to
our east should push our thunderstorm coverage up as we reinforce
available moisture and draw in weak inflections around the high.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
DISCUSSION...Mollere
PREVIOUS DISCUSSION...Meyer/Rasmussen
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
[top]
Area Forecast Discussion
National Weather Service Flagstaff AZ
857 PM MST SUN JUN 26 2016
.SYNOPSIS...On Monday, expect scattered showers and thunderstorms,
primarily along and south of the Mogollon Rim. Strong, gusty
winds are possible near any storms. Beginning Tuesday, monsoonal
moisture is forecast to spread across all of northern Arizona
leading to daily chances for showers and thunderstorms through the
week.
&&
.DISCUSSION...
Only isolated and generally light showers are expected to continue
this evening and overnight. Additional storm development is likely
by late Monday morning.
&&
.PREV DISCUSSION /406 PM MST/...So far today, shower and
thunderstorm activity has generally occurred along and south of
a line from Window Rock to Heber-Overgaard. This area will likely
continue to be the focus for shower activity today, although some
showers may expand westward a bit to include Payson and Clints
Well this afternoon and evening.
On Monday, increasing moisture is forecast along and south of the
Mogollon Rim. This will lead to better chances for showers and
thunderstorms there. These storms will once again be high based,
so strong outflow winds will be the primary hazard.
Beginning Tuesday, high pressure in place near the Four Corners is
forecast to lead to an active monsoon pattern. A moist easterly
flow will transition to a moist southerly wind around the middle
of the week. This will draw deeper moisture into the region
leading to increasing chances for showers and thunderstorms across
all of northern Arizona. This moisture is expected to remain in
place over the following days causing daily chances for showers
and thunderstorms through the remainder of the week.
&&
.AVIATION...For the 06Z Package...Isolated to scattered showers
and thunderstorms expect to develop mainly southeast of a KFLG-
KRQE line after 18Z Monday. Otherwise, expect VFR conditions.
Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Expect deeper moisture with increasing coverage in
showers and thunderstorms Monday and Tuesday. Storm motion
Monday will generally be from southeast to northwest and south to
north on Tuesday. Expect erratic and gusty winds near any showers
and storms.
Wednesday through Friday...An active wet Monsoon weather pattern
is expected with numerous showers and thunderstorms each day
across northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...KD/RR
AVIATION...KD
FIRE WEATHER...MAS
For Northern Arizona weather information visit
weather.gov/flagstaff
[top]
Area Forecast Discussion
National Weather Service Phoenix AZ
730 PM MST SUN JUN 26 2016
.SYNOPSIS...
High pressure will move somewhat north and east of Arizona this week
allowing warm temperatures to prevail, but also bring a couple of
weather disturbances through the state. An increase in monsoon
moisture will accompany these weather systems providing a threat of
afternoon and evening showers and thunderstorms the remainder of
week.
&&
.DISCUSSION...
A well defined circulation center was quite evident in WV imagery
across far northern Sonora this evening with stronger ascent and
upper divergent signatures analyzed throughout SE AZ. 00Z KTWC
sampled rather modest Sfc-H7 8 g/kg mixing ratios, however deep
layer moisture flux has advected more favorable 10-11 g/kg profiles
northward per objective analysis. Given the general UVV and weakly
capped MLCapes around 500 J/kg, more robust convection has developed
along the I-19 corridor. Closer towards central AZ, reduced daytime
insolation and lower moisture values (closer to 7 g/kg mixing
ratios) have yielded negligible instability despite relatively steep
midlevel lapse rates. Thus, while virga/sprinkles/very light showers
may be possible around the Phoenix metro, convection moving north
may meet a fate of dissipation. Will continue to monitor trends
through the evening, and would be most concerned about stronger
outflows and dust production versus actual storms.
One area of somewhat more concern may be through SW AZ where some
more palpable instability has been analyzed, and
vorticity/divergence fields will translate during the overnight.
Several deterministic models and ensemble means suggest midlevel
moisture lifted towards a steeper lapse rate environment while low
level T/Td spreads narrow. There was enough evidence presented in
models and analysis to increase pops and mention showers through the
SW parts of the CWA later tonight. Otherwise, made some substantial
changes to hourly temperatures based on current trends which were
much cooler than previously advertised.
&&
.PREVIOUS DISCUSSION...
/240 PM MST SUN JUN 26 2016/
Monday through Saturday...
The forecast becomes very complicated this week with respect to
shower/thunderstorm potential, coverage, and intensity - mainly
across portions of southwest and south central AZ. In other words,
can we call it quasi-unsettled this week?
We know the monsoon moisture boundary arrived in southeast AZ the
past couple of days, and is forecast to spread west and north across
the remainder of southern and central AZ this week. And normally
this time of year once the moistures in place it should be like
clockwork, i.e., first afternoon mountain thunderstorms, then by
evening drifting toward the desert edge including developing on
convective outflows and/or outflow collisions. Not this week, there
is too much going on in the mid and upper atmosphere.
For example, the last vestiges of the northwest Mexico inverted trof
will move into the region Monday afternoon. More cyclonic flow over
southern CA will aid in a threat of thunderstorms over the Joshua
Tree National Park mountains, while difluent flow aloft in southwest
and south central AZ generates convective potential as well. But a
caveat, extensive mid/high clouds associated with the inverted trof
axis may cut down on afternoon heating and the convective potential
in the south central AZ Monday.
And for Tuesday and Tuesday night, while 300/250 mb flows become
southwesterly, a developing 500 mb easterly flow advects a weak mid
level disturbance from New Mexico into southeast and south Central
AZ late Tuesday afternoon and night. 500 mb disturbances usually
spark overnight convection under very moist conditions.
Therefore there is much uncertainty, and we can go on and on for
Wednesday through Saturday. Therefore, the best approach is to call
is quasi-unsettled, or a broad brush approach to shower/thunderstorm
potential since 1) the monsoon moisture will be in place, and 2)
models will no doubt have trouble forecasting any minor
perturbations in this developing convoluted flow aloft.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Low confidence forecast through Monday afternoon as wind
direction/shifts will be dictated by outflow boundaries traveling
from storms more removed from terminal sites. Southwest winds this
evening will shift to an easterly direction earlier than typical due
to outflow propagating from eastern AZ, but timing is very
uncertain. Cigs 12K-15K ft and occasional virga will be common
through Monday morning.
Much better chances for stronger east/northeast outflow winds will
arrive later Monday afternoon. Actual storms may not survive to
lower elevations, though mountain obscuration, blowing dust, and
frequent lightning for arrivals/departures to the east may be
problematic.
Southeast California/Southwest Arizona including KIPL and KBLH:
Cigs in a 10K-15K ft will increase through Monday with occasional
virga, and possibly a few showers reaching the ground at KIPL. While
a south to southeast sfc wind will be preferred, periods of
variability will be common Monday morning (especially around
showers). A few stronger gusts may also be possible for brief
periods. Forecast confidence is only moderate.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday...
Temperatures will continue to "cool" with highs on Wednesday around
105-112F dropping into the 100-110F range by Sunday. As monsoon
moisture levels continue to increase over the region, isolated
thunderstorms are possible each afternoon/evening over much of the
desert southwest, with the highest chances over the higher terrain
of central and eastern Arizona. Accompanying any storm that develops
will be wetting rains, gusty erratic winds, and lightning. This
increase in moisture will support a rise in minimum humidities, with
values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...MO/Vasquez
AVIATION...MO
FIRE WEATHER...Hernandez
Area Forecast Discussion
National Weather Service Phoenix AZ
730 PM MST SUN JUN 26 2016
.SYNOPSIS...
High pressure will move somewhat north and east of Arizona this week
allowing warm temperatures to prevail, but also bring a couple of
weather disturbances through the state. An increase in monsoon
moisture will accompany these weather systems providing a threat of
afternoon and evening showers and thunderstorms the remainder of
week.
&&
.DISCUSSION...
A well defined circulation center was quite evident in WV imagery
across far northern Sonora this evening with stronger ascent and
upper divergent signatures analyzed throughout SE AZ. 00Z KTWC
sampled rather modest Sfc-H7 8 g/kg mixing ratios, however deep
layer moisture flux has advected more favorable 10-11 g/kg profiles
northward per objective analysis. Given the general UVV and weakly
capped MLCapes around 500 J/kg, more robust convection has developed
along the I-19 corridor. Closer towards central AZ, reduced daytime
insolation and lower moisture values (closer to 7 g/kg mixing
ratios) have yielded negligible instability despite relatively steep
midlevel lapse rates. Thus, while virga/sprinkles/very light showers
may be possible around the Phoenix metro, convection moving north
may meet a fate of dissipation. Will continue to monitor trends
through the evening, and would be most concerned about stronger
outflows and dust production versus actual storms.
One area of somewhat more concern may be through SW AZ where some
more palpable instability has been analyzed, and
vorticity/divergence fields will translate during the overnight.
Several deterministic models and ensemble means suggest midlevel
moisture lifted towards a steeper lapse rate environment while low
level T/Td spreads narrow. There was enough evidence presented in
models and analysis to increase pops and mention showers through the
SW parts of the CWA later tonight. Otherwise, made some substantial
changes to hourly temperatures based on current trends which were
much cooler than previously advertised.
&&
.PREVIOUS DISCUSSION...
/240 PM MST SUN JUN 26 2016/
Monday through Saturday...
The forecast becomes very complicated this week with respect to
shower/thunderstorm potential, coverage, and intensity - mainly
across portions of southwest and south central AZ. In other words,
can we call it quasi-unsettled this week?
We know the monsoon moisture boundary arrived in southeast AZ the
past couple of days, and is forecast to spread west and north across
the remainder of southern and central AZ this week. And normally
this time of year once the moistures in place it should be like
clockwork, i.e., first afternoon mountain thunderstorms, then by
evening drifting toward the desert edge including developing on
convective outflows and/or outflow collisions. Not this week, there
is too much going on in the mid and upper atmosphere.
For example, the last vestiges of the northwest Mexico inverted trof
will move into the region Monday afternoon. More cyclonic flow over
southern CA will aid in a threat of thunderstorms over the Joshua
Tree National Park mountains, while difluent flow aloft in southwest
and south central AZ generates convective potential as well. But a
caveat, extensive mid/high clouds associated with the inverted trof
axis may cut down on afternoon heating and the convective potential
in the south central AZ Monday.
And for Tuesday and Tuesday night, while 300/250 mb flows become
southwesterly, a developing 500 mb easterly flow advects a weak mid
level disturbance from New Mexico into southeast and south Central
AZ late Tuesday afternoon and night. 500 mb disturbances usually
spark overnight convection under very moist conditions.
Therefore there is much uncertainty, and we can go on and on for
Wednesday through Saturday. Therefore, the best approach is to call
is quasi-unsettled, or a broad brush approach to shower/thunderstorm
potential since 1) the monsoon moisture will be in place, and 2)
models will no doubt have trouble forecasting any minor
perturbations in this developing convoluted flow aloft.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Low confidence forecast through Monday afternoon as wind
direction/shifts will be dictated by outflow boundaries traveling
from storms more removed from terminal sites. Southwest winds this
evening will shift to an easterly direction earlier than typical due
to outflow propagating from eastern AZ, but timing is very
uncertain. Cigs 12K-15K ft and occasional virga will be common
through Monday morning.
Much better chances for stronger east/northeast outflow winds will
arrive later Monday afternoon. Actual storms may not survive to
lower elevations, though mountain obscuration, blowing dust, and
frequent lightning for arrivals/departures to the east may be
problematic.
Southeast California/Southwest Arizona including KIPL and KBLH:
Cigs in a 10K-15K ft will increase through Monday with occasional
virga, and possibly a few showers reaching the ground at KIPL. While
a south to southeast sfc wind will be preferred, periods of
variability will be common Monday morning (especially around
showers). A few stronger gusts may also be possible for brief
periods. Forecast confidence is only moderate.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday...
Temperatures will continue to "cool" with highs on Wednesday around
105-112F dropping into the 100-110F range by Sunday. As monsoon
moisture levels continue to increase over the region, isolated
thunderstorms are possible each afternoon/evening over much of the
desert southwest, with the highest chances over the higher terrain
of central and eastern Arizona. Accompanying any storm that develops
will be wetting rains, gusty erratic winds, and lightning. This
increase in moisture will support a rise in minimum humidities, with
values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...MO/Vasquez
AVIATION...MO
FIRE WEATHER...Hernandez
Area Forecast Discussion
National Weather Service Flagstaff AZ
406 PM MST SUN JUN 26 2016
.SYNOPSIS...On Monday, there will be enough moisture in place
over central and eastern Arizona to cause scattered showers and
thunderstorms, primarily along and south of the Mogollon Rim.
Strong, gusty winds are possible near any storms. Beginning
Tuesday, monsoonal moisture is forecast to spread across all of
northern Arizona leading to daily chances for showers and
thunderstorms through the week.
&&
.DISCUSSION...So far today, shower and thunderstorm activity has
generally occurred along and south of a line from Window Rock to
Heber-Overgaard. This area will likely continue to be the focus
for shower activity today, although some showers may expand
westward a bit to include Payson and Clints Well this afternoon
and evening.
On Monday, increasing moisture is forecast along and south of the
Mogollon Rim. This will lead to better chances for showers and
thunderstorms there. These storms will once again be high based,
so strong outflow winds will be the primary hazard.
Beginning Tuesday, high pressure in place near the Four Corners
is forecast to lead to an active monsoon pattern. A moist
easterly flow will transition to a moist southerly wind around
the middle of the week. This will draw deeper moisture into the
region leading to increasing chances for showers and thunderstorms
across all of northern Arizona. This moisture is expected to
remain in place over the following days causing daily chances for
showers and thunderstorms through the remainder of the week.
&&
.AVIATION...For the 00Z Package...Isolated to scattered showers and
thunderstorms with possible wind gusts to 40kts from KFLG-KRQE
southeast until around 02z. Storms will be possible after 17Z over
all of northern Arizona. Otherwise, expect VFR conditions. Aviation
discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Expect deeper moisture with increasing coverage in
showers and thunderstorms Monday and Tuesday. Storm motion Monday
will generally be from southeast to northwest and south to north on
Tuesday. Expect erratic and gusty winds near any showers and storms.
Wednesday through Friday...An active, wet Monsoon weather pattern
is expected with numerous showers and thunderstorms each day
across northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...RR
AVIATION...MAS
FIRE WEATHER...MAS
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Tucson AZ
336 PM MST SUN JUN 26 2016
.SYNOPSIS...Plenty of moisture around this week with an increasing
chance of mainly afternoon and evening showers and thunders across
Southeast Arizona.
&&
DISCUSSION...Convection is finally firing over expected areas,
including areas southeast through southwest of Tucson as well as
the east central mountains (northern Graham and Greenlee
counties). We had a delays in initiation due to morning cloud
cover as well as a bit more convective inhibition to overcome as
per the KTWC morning sounding.
So the strong outflow from the southern Mogollon Rim is just now
pushing southwest into valley locations of Graham county, and it
doesn`t really look as strong as the increasing mid level easterly
flow suggested earlier. Development across southern areas is
increasing, but not anything to write home about either. We may
still have some mid level CAPE for an outflow to tap into later
this evening, so more debris to contend with early Monday morning.
Weak subsidence behind a minor mid level feature shifting north of
the area will probably limit thunderstorms to mainly mountain
areas Monday.
A deeper and stronger fetch around high pressure reconsolidating
to our east should push our thunderstorm coverage up as we
reinforce available moisture and draw in weak inflections around
the high.
&&
AVIATION...VALID THRU 28/00Z.
Isolated to scattered -TSRA/-SHRA. The best timing for TSRA is
mostly from 20Z this afternoon until 27/08Z this evening. Brief
wind gusts to near 40 kts and MVFR conditions due to reduced
visibilities will be possible with the stronger TSRA. Isolated
-SHRA/-TSRA will be possible area-wide late tonight into early
Monday afternoon. Otherwise, cloud decks generally ranging from
10k- 15k ft MSL, and surface wind terrain driven mainly less than
12 kts. Aviation discussion not updated for TAF amendments.
&&
FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this afternoon and evening. Greater coverage of
showers and thunderstorms should then occur Monday through next
Saturday. Otherwise, daytime minimum relative humidity values will
generally range from the mid teens to around 30 percent with fair
to good nighttime recovery. 20-foot winds into Monday as well as
Thursday through Saturday will be terrain driven at less than 15
mph. 20-foot winds Tuesday and Wednesday will generally be from
the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds
Tuesday and Wednesday should prevail from shortly after sunrise
into the early afternoon hours.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Meyer/Rasmussen
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Tucson AZ
336 PM MST SUN JUN 26 2016
.SYNOPSIS...Plenty of moisture around this week with an increasing
chance of mainly afternoon and evening showers and thunders across
Southeast Arizona.
&&
DISCUSSION...Convection is finally firing over expected areas,
including areas southeast through southwest of Tucson as well as
the east central mountains (northern Graham and Greenlee
counties). We had a delays in initiation due to morning cloud
cover as well as a bit more convective inhibition to overcome as
per the KTWC morning sounding.
So the strong outflow from the southern Mogollon Rim is just now
pushing southwest into valley locations of Graham county, and it
doesn`t really look as strong as the increasing mid level easterly
flow suggested earlier. Development across southern areas is
increasing, but not anything to write home about either. We may
still have some mid level CAPE for an outflow to tap into later
this evening, so more debris to contend with early Monday morning.
Weak subsidence behind a minor mid level feature shifting north of
the area will probably limit thunderstorms to mainly mountain
areas Monday.
A deeper and stronger fetch around high pressure reconsolidating
to our east should push our thunderstorm coverage up as we
reinforce available moisture and draw in weak inflections around
the high.
&&
AVIATION...VALID THRU 28/00Z.
Isolated to scattered -TSRA/-SHRA. The best timing for TSRA is
mostly from 20Z this afternoon until 27/08Z this evening. Brief
wind gusts to near 40 kts and MVFR conditions due to reduced
visibilities will be possible with the stronger TSRA. Isolated
-SHRA/-TSRA will be possible area-wide late tonight into early
Monday afternoon. Otherwise, cloud decks generally ranging from
10k- 15k ft MSL, and surface wind terrain driven mainly less than
12 kts. Aviation discussion not updated for TAF amendments.
&&
FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this afternoon and evening. Greater coverage of
showers and thunderstorms should then occur Monday through next
Saturday. Otherwise, daytime minimum relative humidity values will
generally range from the mid teens to around 30 percent with fair
to good nighttime recovery. 20-foot winds into Monday as well as
Thursday through Saturday will be terrain driven at less than 15
mph. 20-foot winds Tuesday and Wednesday will generally be from
the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds
Tuesday and Wednesday should prevail from shortly after sunrise
into the early afternoon hours.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Meyer/Rasmussen
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Phoenix AZ
240 PM SUN JUN 26 2016
.SYNOPSIS...
A very warm air mass will keep temperatures above normal through at
least the first half of the week. A increase in monsoon moisture is
also expected, and will provide a slight threat of afternoon and
evening showers and thunderstorms the remainder of week.
&&
.DISCUSSION...
Tonight...
The inverted trof so noticeable on vapor imagery just south of the
AZ border developed an west-east deformation/stretching zone replete
with considerable mid/high level cloudiness. Cloudiness was able to
retard the heating curve and defer any precip to virga or light
showers with the dense clouds. More is expected overnight. However
there are a few afternoon thunderstorms in the less cloudy areas of
the White Mountains, just west of Nogales along the Mexican border,
and in far southeast AZ at 2 pm mst.
Monday through Saturday
The forecast becomes very complicated this week with respect to
shower/thunderstorm potential, coverage, and intensity, mainly
across portions of southwest and south central AZ. In other words,
can we call it quasi-unsettled this week?
We know the monsoon moisture boundary arrived in southeast AZ the
past couple of days, and is forecast to spread west and north across
the remainder of southern and central AZ this week. And, normally
this time of year once the moistures in place it should be like
clock-work right, i.e., first afternoon mountain thunderstorms then
by evening drifting toward the desert edge, including developing on
convective outflows and/or outflow collisions. Not this week, there
is too much going on in the mid and upper atmosphere.
For example, the last vestiges of the northwest Mexico inverted trof
will move into the region Monday afternoon. More cyclonicity over
southern CA will develop a threat of thunderstorms over the Joshua
Tree National Park mountains, while difluent flow aloft in southwest
and south central AZ generates convective potential as well. But a
caveat, extensive mid/high clouds associated with the inverted trof
axis may cut down on afternoon heating and the convective potential
in the south central AZ Monday.
And for Tuesday and Tuesday night, while 300/250 mb flows become
southwesterly, a developing 500 mb easterly flow advects a weak mid
level disturbance from New Mexico into southeast and south Central
AZ late Tuesday afternoon and night. 500 mb disturbances usually
spark overnight convection under very moist conditions.
Therefore there is much uncertainty, and we can go on and on for
Wednesday through Saturday. Therefore the best approach is to call
is quasi-unsettled, or a broad brush approach to shower/thunderstorm
potential since 1) the monsoon moisture will be in place, and 2)
models will no doubt have trouble forecasting any minor
perturbations in this developing convoluted flow aloft.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Showers moving in from the southeast have caused winds to shift to a
southeasterly direction this afternoon over Phoenix terminals. With
more activity in southeast AZ still propagating to the northwest,
anticipate that these southeasterly winds will stick around for
another hour or so before shifting temporarily back to the west
around 22Z. Speeds will remain around 10 kts, however cannot rule
out gusty erratic winds and blowing dust from distant south and east
AZ storms for the remainder of the day at Phoenix terminals.
However, low confidence in exact spatial and temporal coverage
precludes mention in 18Z TAF. Broken to overcast mid to high clouds
aoa 10kft will continue to advect into the region for the remainder
of the day before decreasing in coverage early tomorrow morning.
Southeast California/Southwest Arizona including KIPL and KBLH:
Skies will remain mostly clear with a few passing high clouds around
15-20 kft. Winds will remain out of the south at KBLH and out of the
southeast at KIPL, with speeds generally around 10-15 kts
accompanied by a few afternoon gusts up to 20 to 25 kts.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday...
Temperatures will continue to "cool," with highs on Wednesday around
105-112F dropping into the 100-110F range by Sunday.
As monsoon moisture levels continue to increase over the region,
isolated thunderstorms are possible each afternoon/evening over much
of the desert southwest, with the highest chances over the higher
terrain of central and eastern Arizona. Accompanying any storm that
develops will be wetting rains, gusty erratic winds, and lightning.
This increase in moisture will support a rise in minimum humidities,
with values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Vasquez
AVIATION...Hernandez
FIRE WEATHER...Hernandez
Area Forecast Discussion
National Weather Service Flagstaff AZ
940 AM MST SUN JUN 26 2016
.SYNOPSIS...Dry and hot weather will persist across far western
Arizona today. Mid level moisture will remain over central and
eastern Arizona through Monday, and bring widely scattered showers
and thunderstorms. Strong, gusty winds are possible near any
storms. Monsoonal moisture to increase and spread across northern
Arizona on Tuesday, with increasing daytime shower and
thunderstorm activity lasting through the week.
&&
.DISCUSSION...For today, the highest moisture and best chances
for showers and thunderstorms will be along and south of the White
Mountains and the eastern Mogollon Rim. Elsewhere, drier air and
more stable conditions will limit convective activity. Slight
chances for showers are forecast along the western Mogollon Rim,
including the city of Flagstaff. This seems reasonable as an
extensive cumulus field is expected to develop with heating. As
highlighted in the previous forecast discussion, today`s storms
will once again be high-based leading to the potential for strong
outflows from collapsing storms.
In terms of forecast updates, the current forecast appears to be
on track and no short term updates are anticipated at this time.
&&
.PREV DISCUSSION /303 AM MST/... Northern Arizona will be slowly
transitioning to a monsoon thunderstorm pattern over the next two
days. Strong and gusty outflow winds should be expected near any
storms or virga. The Flagstaff airport did have 2 periods of
outflow wind gusts to 48 and 47 mph yesterday, an indication of
outflow speeds possible through Monday afternoon.
Satellite imagery this morning shows the monsoonal moisture plume
running from NW Mexico through Tucson then northeastward through
New Mexico. Satellite derived pw values are up to near 1.5 inches
around Tuscon this morning. Models remain consistent in showing
mid level easterly flow increasing across central and southern AZ
today and this will allow moisture to slowly increase across areas
along and south of I-40 through Monday. Areas along the Utah
border to remain hot and nearly cloud free today as this area is
under the high pressure circulation center.
Starting Tuesday, models are in good agreement with moist easterly
flow through Wednesday morning becoming light southerly through
Wednesday. Monsoonal moisture to remain overhead through the week
and daytime precip chances were nudged upward a few points along
the Mogollon Rim. Max temps to cool to near normal for dates
starting Wednesday.
&&
.AVIATION...For the 18Z Package...Isolated to scattered showers and
thunderstorms with possible gusts to 40kts will redevelop from KFLG-
KRQE southeast this afternoon and evening until around 02z.
Otherwise, expect VFR conditions. Aviation discussion not updated
for TAF amendments.
&&
.FIRE WEATHER...Monsoon moisture will slowly increase northward each
day. Expect deeper moisture with increasing coverage in showers and
thunderstorms starting on Monday. Storm motion today and Monday will
generally be from northeast to southwest. Expect erratic and gusty
winds near any showers and storms.
Tuesday through Thursday...An active wet Monsoon weather pattern is
forecast with good shower and thunderstorm coverage each day across
northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...RR/DL
AVIATION...MAS
FIRE WEATHER...MCS
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Tucson AZ
940 AM MST SUN JUN 26 2016
.SYNOPSIS...We now have enough moisture for isolated to scattered
showers and thunderstorms this weekend. A more favorable flow
regime will then provide increased coverage of showers and
thunderstorms Monday through next Saturday.
&&
.DISCUSSION...Still plenty of debris cloud this morning with
embedded light showers. This is going to slow the heating a bit
with initial clearing underway in portions of Cochise and Santa
Cruz counties. The 12Z KTWC sounding still has plenty of moisture
at 1.4 inches precipitable water. The mid level easterly flow has
already increased substantially accompanied by an increase in
shear that should help to organize outflow activity this
afternoon. The direction favors strong outflow off the Mogollon
Rim through Graham county.
Latest HRRR trends push 2 strong outflows westward, including the
Rim shot and a second outflow from activity in Cochise county
pushing west and northwestward. The 12z UofA WRF-NAM paints a
similar scenario with the outflow from the Cochise county activity
pushing through the Tucson Metro area around mid to late
afternoon. Minor adjustments to increase activity in the east
central mountains and subsequent outflow westward, otherwise we
have solid forecast trends. Please see the previous discussion
below for additional details.
&&
.AVIATION...VALID THRU 27/18Z.
Isolated to scattered -TSRA/-SHRA. The best timing for TSRA at
the KTUS/KOLS/KDUG terminals is mostly from 20Z this afternoon
until 27/02Z this evening. Brief wind gusts to near 40 kts and
MVFR conditions due to reduced visibilities will be possible with
the stronger TSRA. Isolated -SHRA/-TSRA will be possible area-wide
late tonight into early Monday morning. Otherwise, cloud decks
generally ranging from 10k- 15k ft MSL, and surface wind terrain
driven mainly less than 12 kts. Aviation discussion not updated
for TAF amendments.
&&
.FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this afternoon and evening. Greater coverage of
showers and thunderstorms should then occur Monday through next
Saturday. Otherwise, daytime minimum relative humidity values will
generally range from the mid teens to around 30 percent with fair
to good nighttime recovery. 20-foot winds into Monday as well as
Thursday through Saturday will be terrain driven at less than 15
mph. 20-foot winds Tuesday and Wednesday will generally be from
the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds
Tuesday and Wednesday should prevail from shortly after sunrise
into the early afternoon hours.
&&
.PREV DISCUSSION...The hi-res models suggest a scenario late
tonight similar to that presently occurring across the area. In
other words, a fairly widespread convective debris cloud cover
with patches of sprinkles or light rain.
26/00Z GFS/ECMWF/CMC remained fairly similar regarding the synoptic
scale pattern regime over the southwestern states starting Monday
and continuing into early next weekend. Strong high pressure aloft
Monday is progged to become centered over southern Utah. The GFS/
ECMWF depict an inverted trough to move into southwestern AZ from
the northern Gulf of California Monday.
Quick glance at the U/A WRF-NAM suggests that showers/tstms Monday
afternoon would only be confined to the White Mountains and near the
international border adjacent Santa Cruz/southern Pima County. Thus,
there is the potential that Monday may be a "down day" perhaps due
to subsidence on the eastern periphery of the aforementioned
inverted trough. Forecast confidence in this particular detail is
somewhat low, however. Thus, for this forecast package, have
continued with scattered showers/tstms mainly from Tucson
eastward/southward.
Thereafter, not much daily variation in shower/tstm coverage is
anticipated Tuesday into next Saturday. The deterministic GFS/ECMWF/
CMC were similar with maintaining fairly ample moisture across this
forecast area. These solutions were similar with the continuation of
a light ely/sely mid-level flow regime thru about Wednesday. The mid-
level flow regime is then progged to become more wly/swly especially
from Tucson westward starting Thursday and continuing into next
Saturday. This subtle change may be sufficient for at least a slight
downward trend in shower/tstm coverage, especially across western
sections. Again, forecast confidence is fairly low at this time in
stating that a definitive downward precip trend anywhere in the area
is in the offing late this week.
High temps for the Tucson metro area and locales west-to-northwest
of Tucson will be near normal during much of this forecast period.
However, daytime temps for locales east-to-south of Tucson, such as
Safford, Douglas and Nogales will average a few degs below normal
this week.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Meyer/Francis
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Phoenix AZ
441 AM MST MON JUN 27 2016
.UPDATE...Updated Aviation Discussion...
&&
.SYNOPSIS...
High pressure will move somewhat north and east of Arizona this week
allowing warm temperatures to prevail, but also bring a couple of
weather disturbances through the state. An increase in monsoon
moisture will accompany these weather systems providing a threat of
afternoon and evening showers and thunderstorms the remainder of
week.
&&
.DISCUSSION...
Early this morning a well defined inverted trof could be seen moving
westward across far southern/southwestern Arizona, and this feature
was clearly evident in vapor imagery as well as recent plot data.
Circulation around this feature was spreading increasing moisture
westward and into the desert west of Phoenix; latest blended total
precipitable water imagery indicated pwat values over 1.2 inches
over portions of the southwest deserts. The inverted trof created
good upper difluence across the central and western deserts and
coupled with a good uvv field, a field of mostly light showers could
be seen spreading into the western deserts at 2 am. As this inverted
trof slowly pushes west today we can expect a continued slight
chance of showers or thunderstorms across much of the lower deserts
to the west of Phoenix including portions of SE California. Later
this afternoon and evening across south central Arizona, the forcing
becomes weaker behind the exiting inverted trof but there is weak
southeast steering flow and sufficient deeper moisture and
instability to allow for a 15-20 percent chance of mainly evening
thunderstorms over the central deserts and a chance of storms over
higher terrain east of Phoenix. This is supported by various
mesoscale models such as the NMM6km. Clouds and moisture working
across the lower deserts will keep high temps today mostly below the
110 degree mark, even over the far western deserts.
Model guidance, including operational runs of the GFS and ECMWF, as
well as ensemble guidance such as the GEFS and NAEFS, continue to
call for a very monsoonal pattern to develop across the desert
southwest starting Tuesday and continuing through the end of the
work week. Initially the main upper high center forms near the four
corners, setting up a deeper southeast steering flow over most of
the area which will steadily transport increasing and deeper
moisture westward over the lower deserts. PWAT values steadily climb
and are forecast to exceed 1.5 inches across the main monsoon
moisture corridor which sets up just east of the lower Colorado
River Valley and extends into far eastern Arizona. The steering flow
is favorable to bring mountain storms into the lower deserts, and
from time to time there will be disturbances rotating around the
main upper high which will serve to enhance thunderstorm coverage
and intensity. Model guidance typically has a hard time with the
exact timing and track of these features and we generally cannot
place a lot of faith in them more than a day or two down the road.
Overall we are looking at a rather broad brushed forecast with 10-20
percent chances of mainly afternoon and evening storms over the
deserts mainly east of the lower CO river valley, and 30-40 percent
chances across the higher terrain east of Phoenix.
Later in the week the upper high starts to shift towards the
southeast and steering flow becomes more southerly. Still, moisture
remains high and in fact the GFS calls for PWAT value in the central
deserts to approach 2 inches later Thursday into Friday. This would
suggest a much better chance for heavy rains to accompany any storms
that develop. Of course, as moisture increases the temperatures will
fall off and by midweek high temps across south central Arizona will
approach and then fall below seasonal normals. It will stay a bit
hotter further west where the atmosphere is a bit drier, with highs
over 110 expected for much of the week.
During the upcoming weekend, as low pressure sets up along the
Pacific northwest coast, and as the high shifts further to the
southeast, the upper streamline fields and steering flow turn
towards the southwest over most of the area. This starts to bring in
drier air from the southwest and we can expect rain chances to
diminish from west to east with time. By Sunday afternoon,
thunderstorm chances look to be confined mostly to higher terrain
areas east and southeast of central Phoenix as skies become mostly
sunny over the central and western deserts.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Much better chances for stronger east/northeast outflow winds are
likely late this afternoon, but confidence in timing is still
somewhat low. Actual storms may not survive to lower elevations,
though mountain obscuration, blowing dust, and frequent lightning for
arrivals/departures to the east may be problematic. Persistent
easterly winds this evening should occur earlier this normal. Sct to
bkn mid and high clouds should persist through Tuesday morning.
Southeast California/Southwest Arizona including KIPL and KBLH:
Cigs in a 10K-15K ft range will persist through this afternoon with
some gradual thinning of cloud cover tonight. Virga showers this
morning over the terminals are likely and should dissipate by around
noon. While a south to southeast sfc wind will be preferred through
this afternoon, winds will eventually become more southwesterly this
evening. A few stronger gusts may also be possible for brief
periods, especially this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday...
Temperatures will continue to "cool" with highs on Wednesday around
105-112F dropping into the 100-110F range by Sunday. As monsoon
moisture levels continue to increase over the region, isolated
thunderstorms are possible each afternoon/evening over much of the
desert southwest, with the highest chances over the higher terrain
of central and eastern Arizona. Accompanying any storm that develops
will be wetting rains, gusty erratic winds, and lightning. This
increase in moisture will support a rise in minimum humidities, with
values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...CB
AVIATION...Kuhlman
FIRE WEATHER...Hernandez
[top]
Area Forecast Discussion
National Weather Service Flagstaff AZ
400 AM MST MON JUN 27 2016
.SYNOPSIS...Expect scattered showers and thunderstorms today along
and south of the Mogollon Rim, and isolated storms elsewhere.
Strong, gusty winds are possible near any storms. Beginning
Tuesday, monsoonal moisture is forecast to increase across all of
northern Arizona leading to daily chances for showers and
thunderstorms through the week.
&&
.DISCUSSION...
Moisture is increasing across central and eastern AZ this morning
per satellite pw estimates and sfc dew point data. The highest pw
values should remain along and south of I-40 today, while shallow
sfc moisture has made it as far north as Page this morning. Thus
scattered showers and thunderstorms are expected this afternoon
and evening along the Mogollon Rim from Happy jack eastward with
isolated storm coverage elsewhere. Most of the storms will be
high based, with strong outflow winds probable from them.
Storm motion today from east to west.
On Tuesday, high pressure aloft will become centered near the
Four Corners. We will see a moist easterly flow Tuesday that
transitions to a moist southerly wind around the middle of the
week. This will draw deeper moisture into the region leading to
increasing chances for showers and thunderstorms across all of
northern Arizona. Expect better chances for measurable rainfall
starting Wednesday. This moisture is expected to remain in place
through at least Saturday bringing daily chances for showers and
thunderstorms.
&&
.AVIATION...For the 12Z Package...Scattered TSRA will develop from
KFLG - KRQE south this afternoon and evening with isolated TSRA
possible elsewhere. Gusty winds near 40 kts and moderate rain
possible in storms. Otherwise, expect VFR conditions. Activity
decreasing aft 06Z though a few showers may continue overnight.
Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...An increase in moisture will lead to scattered
thunderstorms from the Mogollon Rim to the Chuska Mountains south
this afternoon and evening. Isolated storms are possible elsewhere.
Storm motion will be from east to west today. Moisture increases
into Tuesday with scattered storms expected. Storm motion becomes
more south to north on Tuesday. Expect erratic and gusty winds near
any showers and storms.
Wednesday through Friday...An active wet Monsoon weather pattern is
expected with scattered showers and thunderstorms each day across
northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...DL
AVIATION...MCS
FIRE WEATHER...MCS
For Northern Arizona weather information visit
weather.gov/flagstaff
[top]
Area Forecast Discussion
National Weather Service Tucson AZ
345 AM MST MON JUN 27 2016
.SYNOPSIS...Expect scattered showers and thunderstorms into next
weekend. Daytime temperatures will be near normal or a few degrees
below normal, depending upon location.
&&
.DISCUSSION...An expansive area of high pressure aloft will prevail
over the southwest states during the next several days, with the
upper high to generally be centered near the Four Corners region.
The flow around this high pressure in combination with adequate
moisture will translate into isolated to scattered showers and
thunderstorms through Tuesday.
27/00Z GFS/ECMWF/CMC, the 27/03Z SREF and the 27/00Z Univ. of AZ WRF-
NAM/GFS suggest the potential for increased coverage of showers and
thunderstorms starting Wednesday and continuing through at least
Friday. These solutions particularly point toward Wednesday as being
quite active, as a low-level convergence axis becomes established
over central portions of this forecast area. The models also depict
a light mid-level northeasterly steering flow should be present.
Thus, chance-category PoPs exists Wednesday across much of southeast
AZ. Showers and thunderstorms initiating northeast of Tucson
Wednesday would have an increased potential to produce strong and
gusty outflows as they move southwestward. Ample moisture in
combination with a fairly deep sely/sly flow regime will likely
maintain scattered coverage of showers and thunderstorms Thursday and
Friday, with the best chance of precip to occur during the afternoon/
evening hours.
The deterministic GFS/ECMWF were then similar with depicting a drying
trend across western sections next weekend. This drier wly/nwly flow
aloft regime west of Tucson is in response to a broad upper ridge
extending from Texas to Florida, and a weak upper trough near the
west coast. Enough moisture will remain from Tucson eastward/
southward to the New Mexico/international borders to justify isolated
to scattered showers and thunderstorms Saturday and Sunday. Per coord
with WFO PSR, did opt for precip-free conditions next Sunday across
western Pima County.
High temps into next weekend will be quite close to seasonal normals
or a few degrees below normal, depending upon location.
&&
.AVIATION...VALID THRU 28/12Z.
Isolated -SHRA will prevail thru 15Z-17Z this morning, then isolated
to scattered -TSRA/-SHRA this afternoon and evening. Brief wind gusts
to near 40 kts and MVFR conditions due to reduced visibilities will
be possible with the stronger TSRA. Isolated -SHRA/-TSRA will then
occur late tonight into early Tuesday morning. Otherwise, cloud decks
generally ranging from 10k-15k ft msl, and surface wind terrain
driven mainly less than 12 kts. Aviation discussion not updated for
TAF amendments.
&&
.FIRE WEATHER...Scattered showers and thunderstorms will prevail
into next weekend. 20-foot winds today as well as Thursday through
Sunday will be terrain driven at less than 15 mph. 20-foot winds
Tuesday and Wednesday will generally be from the east to southeast at
5-15 mph with gusts of 15-20 mph.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Francis
Area Forecast Discussion
National Weather Service Phoenix AZ
310 AM MST MON JUN 27 2016
.SYNOPSIS...
High pressure will move somewhat north and east of Arizona this week
allowing warm temperatures to prevail, but also bring a couple of
weather disturbances through the state. An increase in monsoon
moisture will accompany these weather systems providing a threat of
afternoon and evening showers and thunderstorms the remainder of
week.
&&
.DISCUSSION...
Early this morning a well defined inverted trof could be seen moving
westward across far southern/southwestern Arizona, and this feature
was clearly evident in vapor imagery as well as recent plot data.
Circulation around this feature was spreading increasing moisture
westward and into the desert west of Phoenix; latest blended total
precipitable water imagery indicated pwat values over 1.2 inches
over portions of the southwest deserts. The inverted trof created
good upper difluence across the central and western deserts and
coupled with a good uvv field, a field of mostly light showers could
be seen spreading into the western deserts at 2 am. As this inverted
trof slowly pushes west today we can expect a continued slight
chance of showers or thunderstorms across much of the lower deserts
to the west of Phoenix including portions of SE California. Later
this afternoon and evening across south central Arizona, the forcing
becomes weaker behind the exiting inverted trof but there is weak
southeast steering flow and sufficient deeper moisture and
instability to allow for a 15-20 percent chance of mainly evening
thunderstorms over the central deserts and a chance of storms over
higher terrain east of Phoenix. This is supported by various
mesoscale models such as the NMM6km. Clouds and moisture working
across the lower deserts will keep high temps today mostly below the
110 degree mark, even over the far western deserts.
Model guidance, including operational runs of the GFS and ECMWF, as
well as ensemble guidance such as the GEFS and NAEFS, continue to
call for a very monsoonal pattern to develop across the desert
southwest starting Tuesday and continuing through the end of the
work week. Initially the main upper high center forms near the four
corners, setting up a deeper southeast steering flow over most of
the area which will steadily transport increasing and deeper
moisture westward over the lower deserts. PWAT values steadily climb
and are forecast to exceed 1.5 inches across the main monsoon
moisture corridor which sets up just east of the lower Colorado
River Valley and extends into far eastern Arizona. The steering flow
is favorable to bring mountain storms into the lower deserts, and
from time to time there will be disturbances rotating around the
main upper high which will serve to enhance thunderstorm coverage
and intensity. Model guidance typically has a hard time with the
exact timing and track of these features and we generally cannot
place a lot of faith in them more than a day or two down the road.
Overall we are looking at a rather broad brushed forecast with 10-20
percent chances of mainly afternoon and evening storms over the
deserts mainly east of the lower CO river valley, and 30-40 percent
chances across the higher terrain east of Phoenix. Later in the week
the upper high starts to shift towards the southeast and steering
flow becomes more southerly. Still, moisture remains high and in
fact the GFS calls for PWAT value in the central deserts to approach
2 inches later Thursday into Friday. This would suggest a much
better chance for heavy rains to accompany any storms that develop.
Of course, as moisture increases the temperatures will fall off and
by midweek high temps across south central Arizona will approach and
then fall below seasonal normals. It will stay a bit hotter further
west where the atmosphere is a bit drier, with highs over 110
expected for much of the week.
During the upcoming weekend, as low pressure sets up along the
Pacific northwest coast, and as the high shifts further to the
southeast, the upper streamline fields and steering flow turn
towards the southwest over most of the area. This starts to bring in
drier air from the southwest and we can expect rain chances to
diminish from west to east with time. By Sunday afternoon,
thunderstorm chances look to be confined mostly to higher terrain
areas east and southeast of central Phoenix as skies become mostly
sunny over the central and western deserts.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Low confidence forecast through Monday afternoon as wind
direction/shifts will be dictated by outflow boundaries traveling
from storms more removed from terminal sites. Southwest winds this
evening will shift to an easterly direction earlier than typical due
to outflow propagating from eastern AZ, but timing is very
uncertain. Cigs 12K-15K ft and occasional virga will be common
through Monday morning.
Much better chances for stronger east/northeast outflow winds will
arrive later Monday afternoon. Actual storms may not survive to
lower elevations, though mountain obscuration, blowing dust, and
frequent lightning for arrivals/departures to the east may be
problematic.
Southeast California/Southwest Arizona including KIPL and KBLH:
Cigs in a 10K-15K ft will increase through Monday with occasional
virga, and possibly a few showers reaching the ground at KIPL. While
a south to southeast sfc wind will be preferred, periods of
variability will be common Monday morning (especially around
showers). A few stronger gusts may also be possible for brief
periods. Forecast confidence is only moderate.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday...
Temperatures will continue to "cool" with highs on Wednesday around
105-112F dropping into the 100-110F range by Sunday. As monsoon
moisture levels continue to increase over the region, isolated
thunderstorms are possible each afternoon/evening over much of the
desert southwest, with the highest chances over the higher terrain
of central and eastern Arizona. Accompanying any storm that develops
will be wetting rains, gusty erratic winds, and lightning. This
increase in moisture will support a rise in minimum humidities, with
values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...CB
AVIATION...MO
FIRE WEATHER...Hernandez
Area Forecast Discussion
National Weather Service Tucson AZ
915 PM MST SUN JUN 26 2016
.SYNOPSIS...Plenty of moisture around this week with an increasing
chance of mainly afternoon and evening showers and thunders across
Southeast Arizona.
&&
.DISCUSSION...Earlier this afternoon and evening showers and
thunderstorms developed generally from extreme southeastern Pima
county and across eastern Santa Cruz county. These showers and
storms then moved rapidly northwest across parts of the Tucson metro
where they caused damage, with power lines and trees down earlier
this evening, mainly in the area from 1st Ave to Campbell Ave and
from River to Prince. In addition, moderate to heavy rainfall
occurred in this same general area, with amounts ranging from around
0.50 -0.80 inches, with only an isolated report above 1.25 inches.
The Tucson Intl Airport reported a total of 0.11 inches so far for
the day.
Radar mosaic from around the region is detecting a batch of light
rain that extends across much of northeast Pima county and further
to the southeast into extreme eastern Santa Cruz county and
southwest Cochise county. All of this activity will continue to
march to the northwest during the remainder of the evening and will
diminish in the process. The inherited POP forecast for the rest of
tonight is still in good shape, so no changes are planned at this
time. However, will continue to monitor satellite and radar trends
and will make adjustments if warranted.
As of 04Z (9 PM MST), temperatures across the region ranged from the
upper 60s to the mid 80s, with the Tucson Intl Airport reporting a
temp of 80 degs, after reaching an afternoon high temp of 102 degs,
which was exactly normal for this date. The rainfall resulted in
cooling temperatures in several locations, especially for the Tucson
metro, so will make some adjustments to the short term hourly
temperature grids to reflect the most recent trends.
For details beyond tonight, please refer to the previous discussion
below.
&&
.AVIATION...VALID THRU 28/06Z.
Isolated to scattered -TSRA/-SHRA. The best timing for -TSRA/-SHRA
is mostly until around 27/08Z. Isolated -SHRA/-TSRA will still be
possible area-wide late tonight into early Monday afternoon.
Otherwise, cloud decks generally ranging from 10k-15K FT MSL, and
surface wind terrain driven mainly less than 12 kts. Aviation
discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Isolated showers and thunderstorms will remain
possible through the rest of this evening and overnight. Greater
coverage of showers and thunderstorms should then occur Monday
through next Saturday. Otherwise, daytime minimum relative humidity
values will generally range from the mid teens to around 30 percent
with fair to good nighttime recovery. 20-foot winds into Monday as
well as Thursday through Saturday will be terrain driven at less
than 15 mph. 20-foot winds Tuesday and Wednesday will generally be
from the east at 5-15 mph with gusts of 15-20 mph. The strongest
speeds Tuesday and Wednesday should prevail from shortly after
sunrise into the early afternoon hours.
&&
.PREV DISCUSSION...Weak subsidence behind a minor mid level feature
shifting north of the area will probably limit thunderstorms to
mainly mountain areas Monday.
A deeper and stronger fetch around high pressure reconsolidating to
our east should push our thunderstorm coverage up as we reinforce
available moisture and draw in weak inflections around the high.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
DISCUSSION...Mollere
PREVIOUS DISCUSSION...Meyer/Rasmussen
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Flagstaff AZ
857 PM MST SUN JUN 26 2016
.SYNOPSIS...On Monday, expect scattered showers and thunderstorms,
primarily along and south of the Mogollon Rim. Strong, gusty
winds are possible near any storms. Beginning Tuesday, monsoonal
moisture is forecast to spread across all of northern Arizona
leading to daily chances for showers and thunderstorms through the
week.
&&
.DISCUSSION...
Only isolated and generally light showers are expected to continue
this evening and overnight. Additional storm development is likely
by late Monday morning.
&&
.PREV DISCUSSION /406 PM MST/...So far today, shower and
thunderstorm activity has generally occurred along and south of
a line from Window Rock to Heber-Overgaard. This area will likely
continue to be the focus for shower activity today, although some
showers may expand westward a bit to include Payson and Clints
Well this afternoon and evening.
On Monday, increasing moisture is forecast along and south of the
Mogollon Rim. This will lead to better chances for showers and
thunderstorms there. These storms will once again be high based,
so strong outflow winds will be the primary hazard.
Beginning Tuesday, high pressure in place near the Four Corners is
forecast to lead to an active monsoon pattern. A moist easterly
flow will transition to a moist southerly wind around the middle
of the week. This will draw deeper moisture into the region
leading to increasing chances for showers and thunderstorms across
all of northern Arizona. This moisture is expected to remain in
place over the following days causing daily chances for showers
and thunderstorms through the remainder of the week.
&&
.AVIATION...For the 06Z Package...Isolated to scattered showers
and thunderstorms expect to develop mainly southeast of a KFLG-
KRQE line after 18Z Monday. Otherwise, expect VFR conditions.
Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Expect deeper moisture with increasing coverage in
showers and thunderstorms Monday and Tuesday. Storm motion
Monday will generally be from southeast to northwest and south to
north on Tuesday. Expect erratic and gusty winds near any showers
and storms.
Wednesday through Friday...An active wet Monsoon weather pattern
is expected with numerous showers and thunderstorms each day
across northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...KD/RR
AVIATION...KD
FIRE WEATHER...MAS
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Phoenix AZ
730 PM MST SUN JUN 26 2016
.SYNOPSIS...
High pressure will move somewhat north and east of Arizona this week
allowing warm temperatures to prevail, but also bring a couple of
weather disturbances through the state. An increase in monsoon
moisture will accompany these weather systems providing a threat of
afternoon and evening showers and thunderstorms the remainder of
week.
&&
.DISCUSSION...
A well defined circulation center was quite evident in WV imagery
across far northern Sonora this evening with stronger ascent and
upper divergent signatures analyzed throughout SE AZ. 00Z KTWC
sampled rather modest Sfc-H7 8 g/kg mixing ratios, however deep
layer moisture flux has advected more favorable 10-11 g/kg profiles
northward per objective analysis. Given the general UVV and weakly
capped MLCapes around 500 J/kg, more robust convection has developed
along the I-19 corridor. Closer towards central AZ, reduced daytime
insolation and lower moisture values (closer to 7 g/kg mixing
ratios) have yielded negligible instability despite relatively steep
midlevel lapse rates. Thus, while virga/sprinkles/very light showers
may be possible around the Phoenix metro, convection moving north
may meet a fate of dissipation. Will continue to monitor trends
through the evening, and would be most concerned about stronger
outflows and dust production versus actual storms.
One area of somewhat more concern may be through SW AZ where some
more palpable instability has been analyzed, and
vorticity/divergence fields will translate during the overnight.
Several deterministic models and ensemble means suggest midlevel
moisture lifted towards a steeper lapse rate environment while low
level T/Td spreads narrow. There was enough evidence presented in
models and analysis to increase pops and mention showers through the
SW parts of the CWA later tonight. Otherwise, made some substantial
changes to hourly temperatures based on current trends which were
much cooler than previously advertised.
&&
.PREVIOUS DISCUSSION...
/240 PM MST SUN JUN 26 2016/
Monday through Saturday...
The forecast becomes very complicated this week with respect to
shower/thunderstorm potential, coverage, and intensity - mainly
across portions of southwest and south central AZ. In other words,
can we call it quasi-unsettled this week?
We know the monsoon moisture boundary arrived in southeast AZ the
past couple of days, and is forecast to spread west and north across
the remainder of southern and central AZ this week. And normally
this time of year once the moistures in place it should be like
clockwork, i.e., first afternoon mountain thunderstorms, then by
evening drifting toward the desert edge including developing on
convective outflows and/or outflow collisions. Not this week, there
is too much going on in the mid and upper atmosphere.
For example, the last vestiges of the northwest Mexico inverted trof
will move into the region Monday afternoon. More cyclonic flow over
southern CA will aid in a threat of thunderstorms over the Joshua
Tree National Park mountains, while difluent flow aloft in southwest
and south central AZ generates convective potential as well. But a
caveat, extensive mid/high clouds associated with the inverted trof
axis may cut down on afternoon heating and the convective potential
in the south central AZ Monday.
And for Tuesday and Tuesday night, while 300/250 mb flows become
southwesterly, a developing 500 mb easterly flow advects a weak mid
level disturbance from New Mexico into southeast and south Central
AZ late Tuesday afternoon and night. 500 mb disturbances usually
spark overnight convection under very moist conditions.
Therefore there is much uncertainty, and we can go on and on for
Wednesday through Saturday. Therefore, the best approach is to call
is quasi-unsettled, or a broad brush approach to shower/thunderstorm
potential since 1) the monsoon moisture will be in place, and 2)
models will no doubt have trouble forecasting any minor
perturbations in this developing convoluted flow aloft.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Low confidence forecast through Monday afternoon as wind
direction/shifts will be dictated by outflow boundaries traveling
from storms more removed from terminal sites. Southwest winds this
evening will shift to an easterly direction earlier than typical due
to outflow propagating from eastern AZ, but timing is very
uncertain. Cigs 12K-15K ft and occasional virga will be common
through Monday morning.
Much better chances for stronger east/northeast outflow winds will
arrive later Monday afternoon. Actual storms may not survive to
lower elevations, though mountain obscuration, blowing dust, and
frequent lightning for arrivals/departures to the east may be
problematic.
Southeast California/Southwest Arizona including KIPL and KBLH:
Cigs in a 10K-15K ft will increase through Monday with occasional
virga, and possibly a few showers reaching the ground at KIPL. While
a south to southeast sfc wind will be preferred, periods of
variability will be common Monday morning (especially around
showers). A few stronger gusts may also be possible for brief
periods. Forecast confidence is only moderate.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday...
Temperatures will continue to "cool" with highs on Wednesday around
105-112F dropping into the 100-110F range by Sunday. As monsoon
moisture levels continue to increase over the region, isolated
thunderstorms are possible each afternoon/evening over much of the
desert southwest, with the highest chances over the higher terrain
of central and eastern Arizona. Accompanying any storm that develops
will be wetting rains, gusty erratic winds, and lightning. This
increase in moisture will support a rise in minimum humidities, with
values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...MO/Vasquez
AVIATION...MO
FIRE WEATHER...Hernandez
Area Forecast Discussion
National Weather Service Phoenix AZ
730 PM MST SUN JUN 26 2016
.SYNOPSIS...
High pressure will move somewhat north and east of Arizona this week
allowing warm temperatures to prevail, but also bring a couple of
weather disturbances through the state. An increase in monsoon
moisture will accompany these weather systems providing a threat of
afternoon and evening showers and thunderstorms the remainder of
week.
&&
.DISCUSSION...
A well defined circulation center was quite evident in WV imagery
across far northern Sonora this evening with stronger ascent and
upper divergent signatures analyzed throughout SE AZ. 00Z KTWC
sampled rather modest Sfc-H7 8 g/kg mixing ratios, however deep
layer moisture flux has advected more favorable 10-11 g/kg profiles
northward per objective analysis. Given the general UVV and weakly
capped MLCapes around 500 J/kg, more robust convection has developed
along the I-19 corridor. Closer towards central AZ, reduced daytime
insolation and lower moisture values (closer to 7 g/kg mixing
ratios) have yielded negligible instability despite relatively steep
midlevel lapse rates. Thus, while virga/sprinkles/very light showers
may be possible around the Phoenix metro, convection moving north
may meet a fate of dissipation. Will continue to monitor trends
through the evening, and would be most concerned about stronger
outflows and dust production versus actual storms.
One area of somewhat more concern may be through SW AZ where some
more palpable instability has been analyzed, and
vorticity/divergence fields will translate during the overnight.
Several deterministic models and ensemble means suggest midlevel
moisture lifted towards a steeper lapse rate environment while low
level T/Td spreads narrow. There was enough evidence presented in
models and analysis to increase pops and mention showers through the
SW parts of the CWA later tonight. Otherwise, made some substantial
changes to hourly temperatures based on current trends which were
much cooler than previously advertised.
&&
.PREVIOUS DISCUSSION...
/240 PM MST SUN JUN 26 2016/
Monday through Saturday...
The forecast becomes very complicated this week with respect to
shower/thunderstorm potential, coverage, and intensity - mainly
across portions of southwest and south central AZ. In other words,
can we call it quasi-unsettled this week?
We know the monsoon moisture boundary arrived in southeast AZ the
past couple of days, and is forecast to spread west and north across
the remainder of southern and central AZ this week. And normally
this time of year once the moistures in place it should be like
clockwork, i.e., first afternoon mountain thunderstorms, then by
evening drifting toward the desert edge including developing on
convective outflows and/or outflow collisions. Not this week, there
is too much going on in the mid and upper atmosphere.
For example, the last vestiges of the northwest Mexico inverted trof
will move into the region Monday afternoon. More cyclonic flow over
southern CA will aid in a threat of thunderstorms over the Joshua
Tree National Park mountains, while difluent flow aloft in southwest
and south central AZ generates convective potential as well. But a
caveat, extensive mid/high clouds associated with the inverted trof
axis may cut down on afternoon heating and the convective potential
in the south central AZ Monday.
And for Tuesday and Tuesday night, while 300/250 mb flows become
southwesterly, a developing 500 mb easterly flow advects a weak mid
level disturbance from New Mexico into southeast and south Central
AZ late Tuesday afternoon and night. 500 mb disturbances usually
spark overnight convection under very moist conditions.
Therefore there is much uncertainty, and we can go on and on for
Wednesday through Saturday. Therefore, the best approach is to call
is quasi-unsettled, or a broad brush approach to shower/thunderstorm
potential since 1) the monsoon moisture will be in place, and 2)
models will no doubt have trouble forecasting any minor
perturbations in this developing convoluted flow aloft.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Low confidence forecast through Monday afternoon as wind
direction/shifts will be dictated by outflow boundaries traveling
from storms more removed from terminal sites. Southwest winds this
evening will shift to an easterly direction earlier than typical due
to outflow propagating from eastern AZ, but timing is very
uncertain. Cigs 12K-15K ft and occasional virga will be common
through Monday morning.
Much better chances for stronger east/northeast outflow winds will
arrive later Monday afternoon. Actual storms may not survive to
lower elevations, though mountain obscuration, blowing dust, and
frequent lightning for arrivals/departures to the east may be
problematic.
Southeast California/Southwest Arizona including KIPL and KBLH:
Cigs in a 10K-15K ft will increase through Monday with occasional
virga, and possibly a few showers reaching the ground at KIPL. While
a south to southeast sfc wind will be preferred, periods of
variability will be common Monday morning (especially around
showers). A few stronger gusts may also be possible for brief
periods. Forecast confidence is only moderate.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday...
Temperatures will continue to "cool" with highs on Wednesday around
105-112F dropping into the 100-110F range by Sunday. As monsoon
moisture levels continue to increase over the region, isolated
thunderstorms are possible each afternoon/evening over much of the
desert southwest, with the highest chances over the higher terrain
of central and eastern Arizona. Accompanying any storm that develops
will be wetting rains, gusty erratic winds, and lightning. This
increase in moisture will support a rise in minimum humidities, with
values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...MO/Vasquez
AVIATION...MO
FIRE WEATHER...Hernandez
Area Forecast Discussion
National Weather Service Flagstaff AZ
406 PM MST SUN JUN 26 2016
.SYNOPSIS...On Monday, there will be enough moisture in place
over central and eastern Arizona to cause scattered showers and
thunderstorms, primarily along and south of the Mogollon Rim.
Strong, gusty winds are possible near any storms. Beginning
Tuesday, monsoonal moisture is forecast to spread across all of
northern Arizona leading to daily chances for showers and
thunderstorms through the week.
&&
.DISCUSSION...So far today, shower and thunderstorm activity has
generally occurred along and south of a line from Window Rock to
Heber-Overgaard. This area will likely continue to be the focus
for shower activity today, although some showers may expand
westward a bit to include Payson and Clints Well this afternoon
and evening.
On Monday, increasing moisture is forecast along and south of the
Mogollon Rim. This will lead to better chances for showers and
thunderstorms there. These storms will once again be high based,
so strong outflow winds will be the primary hazard.
Beginning Tuesday, high pressure in place near the Four Corners
is forecast to lead to an active monsoon pattern. A moist
easterly flow will transition to a moist southerly wind around
the middle of the week. This will draw deeper moisture into the
region leading to increasing chances for showers and thunderstorms
across all of northern Arizona. This moisture is expected to
remain in place over the following days causing daily chances for
showers and thunderstorms through the remainder of the week.
&&
.AVIATION...For the 00Z Package...Isolated to scattered showers and
thunderstorms with possible wind gusts to 40kts from KFLG-KRQE
southeast until around 02z. Storms will be possible after 17Z over
all of northern Arizona. Otherwise, expect VFR conditions. Aviation
discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Expect deeper moisture with increasing coverage in
showers and thunderstorms Monday and Tuesday. Storm motion Monday
will generally be from southeast to northwest and south to north on
Tuesday. Expect erratic and gusty winds near any showers and storms.
Wednesday through Friday...An active, wet Monsoon weather pattern
is expected with numerous showers and thunderstorms each day
across northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...RR
AVIATION...MAS
FIRE WEATHER...MAS
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Tucson AZ
336 PM MST SUN JUN 26 2016
.SYNOPSIS...Plenty of moisture around this week with an increasing
chance of mainly afternoon and evening showers and thunders across
Southeast Arizona.
&&
DISCUSSION...Convection is finally firing over expected areas,
including areas southeast through southwest of Tucson as well as
the east central mountains (northern Graham and Greenlee
counties). We had a delays in initiation due to morning cloud
cover as well as a bit more convective inhibition to overcome as
per the KTWC morning sounding.
So the strong outflow from the southern Mogollon Rim is just now
pushing southwest into valley locations of Graham county, and it
doesn`t really look as strong as the increasing mid level easterly
flow suggested earlier. Development across southern areas is
increasing, but not anything to write home about either. We may
still have some mid level CAPE for an outflow to tap into later
this evening, so more debris to contend with early Monday morning.
Weak subsidence behind a minor mid level feature shifting north of
the area will probably limit thunderstorms to mainly mountain
areas Monday.
A deeper and stronger fetch around high pressure reconsolidating
to our east should push our thunderstorm coverage up as we
reinforce available moisture and draw in weak inflections around
the high.
&&
AVIATION...VALID THRU 28/00Z.
Isolated to scattered -TSRA/-SHRA. The best timing for TSRA is
mostly from 20Z this afternoon until 27/08Z this evening. Brief
wind gusts to near 40 kts and MVFR conditions due to reduced
visibilities will be possible with the stronger TSRA. Isolated
-SHRA/-TSRA will be possible area-wide late tonight into early
Monday afternoon. Otherwise, cloud decks generally ranging from
10k- 15k ft MSL, and surface wind terrain driven mainly less than
12 kts. Aviation discussion not updated for TAF amendments.
&&
FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this afternoon and evening. Greater coverage of
showers and thunderstorms should then occur Monday through next
Saturday. Otherwise, daytime minimum relative humidity values will
generally range from the mid teens to around 30 percent with fair
to good nighttime recovery. 20-foot winds into Monday as well as
Thursday through Saturday will be terrain driven at less than 15
mph. 20-foot winds Tuesday and Wednesday will generally be from
the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds
Tuesday and Wednesday should prevail from shortly after sunrise
into the early afternoon hours.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Meyer/Rasmussen
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Tucson AZ
336 PM MST SUN JUN 26 2016
.SYNOPSIS...Plenty of moisture around this week with an increasing
chance of mainly afternoon and evening showers and thunders across
Southeast Arizona.
&&
DISCUSSION...Convection is finally firing over expected areas,
including areas southeast through southwest of Tucson as well as
the east central mountains (northern Graham and Greenlee
counties). We had a delays in initiation due to morning cloud
cover as well as a bit more convective inhibition to overcome as
per the KTWC morning sounding.
So the strong outflow from the southern Mogollon Rim is just now
pushing southwest into valley locations of Graham county, and it
doesn`t really look as strong as the increasing mid level easterly
flow suggested earlier. Development across southern areas is
increasing, but not anything to write home about either. We may
still have some mid level CAPE for an outflow to tap into later
this evening, so more debris to contend with early Monday morning.
Weak subsidence behind a minor mid level feature shifting north of
the area will probably limit thunderstorms to mainly mountain
areas Monday.
A deeper and stronger fetch around high pressure reconsolidating
to our east should push our thunderstorm coverage up as we
reinforce available moisture and draw in weak inflections around
the high.
&&
AVIATION...VALID THRU 28/00Z.
Isolated to scattered -TSRA/-SHRA. The best timing for TSRA is
mostly from 20Z this afternoon until 27/08Z this evening. Brief
wind gusts to near 40 kts and MVFR conditions due to reduced
visibilities will be possible with the stronger TSRA. Isolated
-SHRA/-TSRA will be possible area-wide late tonight into early
Monday afternoon. Otherwise, cloud decks generally ranging from
10k- 15k ft MSL, and surface wind terrain driven mainly less than
12 kts. Aviation discussion not updated for TAF amendments.
&&
FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this afternoon and evening. Greater coverage of
showers and thunderstorms should then occur Monday through next
Saturday. Otherwise, daytime minimum relative humidity values will
generally range from the mid teens to around 30 percent with fair
to good nighttime recovery. 20-foot winds into Monday as well as
Thursday through Saturday will be terrain driven at less than 15
mph. 20-foot winds Tuesday and Wednesday will generally be from
the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds
Tuesday and Wednesday should prevail from shortly after sunrise
into the early afternoon hours.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Meyer/Rasmussen
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Phoenix AZ
240 PM SUN JUN 26 2016
.SYNOPSIS...
A very warm air mass will keep temperatures above normal through at
least the first half of the week. A increase in monsoon moisture is
also expected, and will provide a slight threat of afternoon and
evening showers and thunderstorms the remainder of week.
&&
.DISCUSSION...
Tonight...
The inverted trof so noticeable on vapor imagery just south of the
AZ border developed an west-east deformation/stretching zone replete
with considerable mid/high level cloudiness. Cloudiness was able to
retard the heating curve and defer any precip to virga or light
showers with the dense clouds. More is expected overnight. However
there are a few afternoon thunderstorms in the less cloudy areas of
the White Mountains, just west of Nogales along the Mexican border,
and in far southeast AZ at 2 pm mst.
Monday through Saturday
The forecast becomes very complicated this week with respect to
shower/thunderstorm potential, coverage, and intensity, mainly
across portions of southwest and south central AZ. In other words,
can we call it quasi-unsettled this week?
We know the monsoon moisture boundary arrived in southeast AZ the
past couple of days, and is forecast to spread west and north across
the remainder of southern and central AZ this week. And, normally
this time of year once the moistures in place it should be like
clock-work right, i.e., first afternoon mountain thunderstorms then
by evening drifting toward the desert edge, including developing on
convective outflows and/or outflow collisions. Not this week, there
is too much going on in the mid and upper atmosphere.
For example, the last vestiges of the northwest Mexico inverted trof
will move into the region Monday afternoon. More cyclonicity over
southern CA will develop a threat of thunderstorms over the Joshua
Tree National Park mountains, while difluent flow aloft in southwest
and south central AZ generates convective potential as well. But a
caveat, extensive mid/high clouds associated with the inverted trof
axis may cut down on afternoon heating and the convective potential
in the south central AZ Monday.
And for Tuesday and Tuesday night, while 300/250 mb flows become
southwesterly, a developing 500 mb easterly flow advects a weak mid
level disturbance from New Mexico into southeast and south Central
AZ late Tuesday afternoon and night. 500 mb disturbances usually
spark overnight convection under very moist conditions.
Therefore there is much uncertainty, and we can go on and on for
Wednesday through Saturday. Therefore the best approach is to call
is quasi-unsettled, or a broad brush approach to shower/thunderstorm
potential since 1) the monsoon moisture will be in place, and 2)
models will no doubt have trouble forecasting any minor
perturbations in this developing convoluted flow aloft.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Showers moving in from the southeast have caused winds to shift to a
southeasterly direction this afternoon over Phoenix terminals. With
more activity in southeast AZ still propagating to the northwest,
anticipate that these southeasterly winds will stick around for
another hour or so before shifting temporarily back to the west
around 22Z. Speeds will remain around 10 kts, however cannot rule
out gusty erratic winds and blowing dust from distant south and east
AZ storms for the remainder of the day at Phoenix terminals.
However, low confidence in exact spatial and temporal coverage
precludes mention in 18Z TAF. Broken to overcast mid to high clouds
aoa 10kft will continue to advect into the region for the remainder
of the day before decreasing in coverage early tomorrow morning.
Southeast California/Southwest Arizona including KIPL and KBLH:
Skies will remain mostly clear with a few passing high clouds around
15-20 kft. Winds will remain out of the south at KBLH and out of the
southeast at KIPL, with speeds generally around 10-15 kts
accompanied by a few afternoon gusts up to 20 to 25 kts.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday...
Temperatures will continue to "cool," with highs on Wednesday around
105-112F dropping into the 100-110F range by Sunday.
As monsoon moisture levels continue to increase over the region,
isolated thunderstorms are possible each afternoon/evening over much
of the desert southwest, with the highest chances over the higher
terrain of central and eastern Arizona. Accompanying any storm that
develops will be wetting rains, gusty erratic winds, and lightning.
This increase in moisture will support a rise in minimum humidities,
with values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Vasquez
AVIATION...Hernandez
FIRE WEATHER...Hernandez
Area Forecast Discussion
National Weather Service Flagstaff AZ
940 AM MST SUN JUN 26 2016
.SYNOPSIS...Dry and hot weather will persist across far western
Arizona today. Mid level moisture will remain over central and
eastern Arizona through Monday, and bring widely scattered showers
and thunderstorms. Strong, gusty winds are possible near any
storms. Monsoonal moisture to increase and spread across northern
Arizona on Tuesday, with increasing daytime shower and
thunderstorm activity lasting through the week.
&&
.DISCUSSION...For today, the highest moisture and best chances
for showers and thunderstorms will be along and south of the White
Mountains and the eastern Mogollon Rim. Elsewhere, drier air and
more stable conditions will limit convective activity. Slight
chances for showers are forecast along the western Mogollon Rim,
including the city of Flagstaff. This seems reasonable as an
extensive cumulus field is expected to develop with heating. As
highlighted in the previous forecast discussion, today`s storms
will once again be high-based leading to the potential for strong
outflows from collapsing storms.
In terms of forecast updates, the current forecast appears to be
on track and no short term updates are anticipated at this time.
&&
.PREV DISCUSSION /303 AM MST/... Northern Arizona will be slowly
transitioning to a monsoon thunderstorm pattern over the next two
days. Strong and gusty outflow winds should be expected near any
storms or virga. The Flagstaff airport did have 2 periods of
outflow wind gusts to 48 and 47 mph yesterday, an indication of
outflow speeds possible through Monday afternoon.
Satellite imagery this morning shows the monsoonal moisture plume
running from NW Mexico through Tucson then northeastward through
New Mexico. Satellite derived pw values are up to near 1.5 inches
around Tuscon this morning. Models remain consistent in showing
mid level easterly flow increasing across central and southern AZ
today and this will allow moisture to slowly increase across areas
along and south of I-40 through Monday. Areas along the Utah
border to remain hot and nearly cloud free today as this area is
under the high pressure circulation center.
Starting Tuesday, models are in good agreement with moist easterly
flow through Wednesday morning becoming light southerly through
Wednesday. Monsoonal moisture to remain overhead through the week
and daytime precip chances were nudged upward a few points along
the Mogollon Rim. Max temps to cool to near normal for dates
starting Wednesday.
&&
.AVIATION...For the 18Z Package...Isolated to scattered showers and
thunderstorms with possible gusts to 40kts will redevelop from KFLG-
KRQE southeast this afternoon and evening until around 02z.
Otherwise, expect VFR conditions. Aviation discussion not updated
for TAF amendments.
&&
.FIRE WEATHER...Monsoon moisture will slowly increase northward each
day. Expect deeper moisture with increasing coverage in showers and
thunderstorms starting on Monday. Storm motion today and Monday will
generally be from northeast to southwest. Expect erratic and gusty
winds near any showers and storms.
Tuesday through Thursday...An active wet Monsoon weather pattern is
forecast with good shower and thunderstorm coverage each day across
northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...RR/DL
AVIATION...MAS
FIRE WEATHER...MCS
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Tucson AZ
940 AM MST SUN JUN 26 2016
.SYNOPSIS...We now have enough moisture for isolated to scattered
showers and thunderstorms this weekend. A more favorable flow
regime will then provide increased coverage of showers and
thunderstorms Monday through next Saturday.
&&
.DISCUSSION...Still plenty of debris cloud this morning with
embedded light showers. This is going to slow the heating a bit
with initial clearing underway in portions of Cochise and Santa
Cruz counties. The 12Z KTWC sounding still has plenty of moisture
at 1.4 inches precipitable water. The mid level easterly flow has
already increased substantially accompanied by an increase in
shear that should help to organize outflow activity this
afternoon. The direction favors strong outflow off the Mogollon
Rim through Graham county.
Latest HRRR trends push 2 strong outflows westward, including the
Rim shot and a second outflow from activity in Cochise county
pushing west and northwestward. The 12z UofA WRF-NAM paints a
similar scenario with the outflow from the Cochise county activity
pushing through the Tucson Metro area around mid to late
afternoon. Minor adjustments to increase activity in the east
central mountains and subsequent outflow westward, otherwise we
have solid forecast trends. Please see the previous discussion
below for additional details.
&&
.AVIATION...VALID THRU 27/18Z.
Isolated to scattered -TSRA/-SHRA. The best timing for TSRA at
the KTUS/KOLS/KDUG terminals is mostly from 20Z this afternoon
until 27/02Z this evening. Brief wind gusts to near 40 kts and
MVFR conditions due to reduced visibilities will be possible with
the stronger TSRA. Isolated -SHRA/-TSRA will be possible area-wide
late tonight into early Monday morning. Otherwise, cloud decks
generally ranging from 10k- 15k ft MSL, and surface wind terrain
driven mainly less than 12 kts. Aviation discussion not updated
for TAF amendments.
&&
.FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this afternoon and evening. Greater coverage of
showers and thunderstorms should then occur Monday through next
Saturday. Otherwise, daytime minimum relative humidity values will
generally range from the mid teens to around 30 percent with fair
to good nighttime recovery. 20-foot winds into Monday as well as
Thursday through Saturday will be terrain driven at less than 15
mph. 20-foot winds Tuesday and Wednesday will generally be from
the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds
Tuesday and Wednesday should prevail from shortly after sunrise
into the early afternoon hours.
&&
.PREV DISCUSSION...The hi-res models suggest a scenario late
tonight similar to that presently occurring across the area. In
other words, a fairly widespread convective debris cloud cover
with patches of sprinkles or light rain.
26/00Z GFS/ECMWF/CMC remained fairly similar regarding the synoptic
scale pattern regime over the southwestern states starting Monday
and continuing into early next weekend. Strong high pressure aloft
Monday is progged to become centered over southern Utah. The GFS/
ECMWF depict an inverted trough to move into southwestern AZ from
the northern Gulf of California Monday.
Quick glance at the U/A WRF-NAM suggests that showers/tstms Monday
afternoon would only be confined to the White Mountains and near the
international border adjacent Santa Cruz/southern Pima County. Thus,
there is the potential that Monday may be a "down day" perhaps due
to subsidence on the eastern periphery of the aforementioned
inverted trough. Forecast confidence in this particular detail is
somewhat low, however. Thus, for this forecast package, have
continued with scattered showers/tstms mainly from Tucson
eastward/southward.
Thereafter, not much daily variation in shower/tstm coverage is
anticipated Tuesday into next Saturday. The deterministic GFS/ECMWF/
CMC were similar with maintaining fairly ample moisture across this
forecast area. These solutions were similar with the continuation of
a light ely/sely mid-level flow regime thru about Wednesday. The mid-
level flow regime is then progged to become more wly/swly especially
from Tucson westward starting Thursday and continuing into next
Saturday. This subtle change may be sufficient for at least a slight
downward trend in shower/tstm coverage, especially across western
sections. Again, forecast confidence is fairly low at this time in
stating that a definitive downward precip trend anywhere in the area
is in the offing late this week.
High temps for the Tucson metro area and locales west-to-northwest
of Tucson will be near normal during much of this forecast period.
However, daytime temps for locales east-to-south of Tucson, such as
Safford, Douglas and Nogales will average a few degs below normal
this week.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Meyer/Francis
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
AREA FORECAST DISCUSSION
National Weather Service San Diego CA
852 AM PDT MON JUN 27 2016
.SYNOPSIS...
High pressure aloft will continue hot weather for inland areas
through Wednesday followed by slow cooling into next weekend as
high pressure aloft weakens and a weak trough of low pressure
develops over the Pacific Northwest. Mid and high level moisture
associated with a disturbance moving through the region will
bring a slight chance of afternoon and early evening thunderstorms
with gusty winds through Wednesday, mainly near the mountains.
The marine layer and onshore flow will keep coastal high
temperatures cooler with areas of night and morning low clouds and
fog.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Visible and radar imagery is showing an easterly upper level wave
moving through the region, bringing mid and high level clouds and
some light radar returns which are likely producing only virga or
sprinkles. The 12Z Miramar sounding shows precipitable water
having increased to 1.48 inches, although the majority of the
moisture appears to be above 700 mb, with a dry layer noted below
700 mb until you reach the 10 deg C marine layer inversion near
1000 ft MSL. It is due to the dry layer below 700 mb that most of
the precipitation may evaporate before reaching the ground, which
is why most of it will appear as virga or maybe some sprinkles.
These clouds will continue to move through Southern California
through the day, although the moisture field from the NAM12 shows
clearing skies intruding in from the south in the afternoon. The
amount of cloud cover we have today, and which locations receive
more sunlight than others, will play a factor in not only how hot
we get today, but also the amount of day-time heating induced
instability. Due to the mid and high clouds, temperatures may be
reduced slightly compared to yesterday. However, with some higher
surface dewpoints in the area (low 60s shown currently over most
coast, valley and desert areas), it may feel more muggy and
uncomfortable.
Despite the increase in moisture and the wave moving overhead, the
elevated instability parameters shown by the forecast models for
this afternoon are not impressive. Also, the strong easterly flow
is not conducive for thunderstorms that develop over the mountains
to maintain their structure. Thus, the latest HRRR run doesn`t
show much shower or thunderstorm activity this afternoon.
Nevertheless, a slight chance for thunderstorms remains in the
forecast today for the mountains, with some activity possibly
being blown west into the valleys.
Meanwhile, marine layer stratus was able to develop over coastal
areas today. Stratus should be able to clear out of inland areas by
late morning, although the decently strong inversion could keep
some low clouds hanging around at the coast.
Models show drier air intruding into Southern California Tuesday
as flow turns southerly in the wake of the easterly wave,
resulting in less of a chance for afternoon mountain
thunderstorms. However, the clearer skies and strong ridge over
the four corners region should result in hotter conditions, with
highs 5-10 degrees above normal. Continued hot for inland areas on
Wednesday, with 850 mb temperatures in the deserts reaching 27-29
deg C, and near 26-27 deg C in the valleys. A Heat Advisory
continues for the deserts, mountains and valleys through
Wednesday. Despite the ridge weakening on Thursday, looks like
the 850 mb temperatures do not decrease much, if at all, so hot
conditions may continue.
Cooler Friday into the weekend as a trough moves into the Pacific
Northwest, with a deepening of the marine layer as well, resulting
in night and morning stratus into the coast and portions of the
valleys.
&&
.AVIATION...
271530Z...Coast/Valleys...Areas of sct-bkn clouds based 800-1200
feet MSL with tops around 1800 ft MSL will burn back to out over the
coastal waters. Local vis 2-4 miles along higher coastal
terrain/mesas. After 28/06z this evening low clouds bkn-ovc based
800-1200 feet MSL with tops around 1800 ft MSL will push inland
about 15 miles with local visibilities 2-4 miles along higher
coastal terrain/mesas. There is a moderate risk that the coastal low
clouds will again be patchy so the confidence is low on the timing
and duration of the bkn low clouds at KSAN tonight.
Mountains and Deserts...Sct-bkn clouds based around 10000 feet MSL
with unrestricted visibilities. This afternoon between 27/19Z and
28/00Z isolated SHRA/TSRA with cloud bases 9000 ft MSL and tops to
35000 ft MSL will be possible over the mountains.
&&
.MARINE...
830 am...No hazardous marine weather is expected through Friday.
&&
.BEACHES...
830 am...The long period south swell will continue to decrease, but
3-5 foot surf will continue on the southwest facing beaches today.
The surf will lower to 2 to 4 feet Tuesday. Another long-period
south swell from 200 degrees will bring 4-7 foot surf to southwest
facing beaches late Wednesday and Thursday along with dangerous rip
currents.
&&
.FIRE WEATHER...
Slight chance of dry lightning over the mountains and portions of
the valleys this afternoon and evening, as an easterly wave moves
through the region. Drying will take place Tuesday through
Wednesday, with maybe just enough moisture leftover on Tuesday to
produce isolated afternoon thunderstorms over the mountains.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX Watches/Warnings/Advisories...
CA...Heat Advisory until 8 PM PDT Wednesday for Apple and Lucerne
Valleys-Coachella Valley-Riverside County Mountains-San
Bernardino County Mountains-San Bernardino and Riverside
County Valleys-The Inland Empire-San Diego County Deserts-
San Diego County Mountains-San Gorgonio Pass Near Banning.
PZ...None.
&&
$$
PUBLIC/FIRE WEATHER...Harrison
AVIATION/MARINE/BEACHES...Small
Area Forecast Discussion
National Weather Service Flagstaff AZ
340 PM MST MON JUN 27 2016
.SYNOPSIS...Daily showers and thunderstorms will increase across
norther Arizona this week as a deep moist southerly flow developes
across the state. Strong, gusty winds are possible near any storms
along with heavy rain and lightning.
&&
.Discussion...Showers and thunderstorms increase across our CWA this
afternoon. The least activity is over northwest Coconino County
this afternoon.
The center of the high pressure will migrate over far northwest New
Mexico by Tuesday. This will bring a deep and moist southeast to
south flow over Arizona. This lead to increasing chances for showers
and thunderstorms each day across all of northern Arizona. Expect
better chances for measurable rainfall starting Wednesday. This
moisture is expected to remain in place through at least Saturday
bringing daily chances for showers and thunderstorms.
&&
.AVIATION...For the 00Z Package...Isolated to scattered TSRA are
expect to continue through 06Z Tue. Gusty winds near 40 kts and
moderate rain are possible in storms. A few showers may continue
overnight, with best chances for this in Coconino and Yavapai
Counties. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...An active monsoon pattern in place across northern
Arizona will cause daily rounds of scattered showers and
thunderstorms. Storm motion will generally be from the south to
north. Expect erratic and gusty winds near showers and storms.
Thursday through Saturday...An active and wet Monsoon weather
pattern will continue with scattered showers and thunderstorms each
day across northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.......MAS
AVIATION.....RR
FIRE WEATHER...RR
For Northern Arizona weather information visit
weather.gov/flagstaff
[top]
Area Forecast Discussion
National Weather Service Phoenix AZ
156 PM MST MON JUN 27 2016
.Update for Aviation and Fire Weather Discussions.
&&
.SYNOPSIS...
High pressure will move somewhat north and east of Arizona this week
allowing warm temperatures to prevail, but also bring a couple of
weather disturbances through the state. An increase in monsoon
moisture will accompany these weather systems providing a threat of
afternoon and evening showers and thunderstorms the remainder of
week.
&&
.DISCUSSION...
Rest of Today and Tonight...
A small upper low centered southwest of El Centro early this
afternoon continues moving westward. Shower activity associated with
it has been weak and isolated. Cloud cover associated with it has
been thinning. Stronger convection has begun to develop over the
higher terrain of northern and southeastern AZ due to destabilization
from surface heating. Storms over the northern half of AZ will also
benefit from some upper level diffluence. Hi-res models have been
depicting this. They are also in generally good agreement that
convection over our area this afternoon and tonight will be spotty.
In fact, they are not overly enthusiastic about southeast AZ. But
there are indications of outflow moving through the south-central AZ
deserts (including Phoenix) from higher terrain late this
afternoon/early evening. With surface dew points in the low 50s and
being on the back side of the aforementioned upper low, it is not
surprising that the models are not depicting an active night for the
lower deserts. But still enough factors to keep slight chances going
(better chance over Zone 24). Also, with the southeasterly steering
flow, debris from Sonora could drift through late tonight.
Tuesday through Thursday...
There is relatively good model agreement on the evolution of the flow
pattern for mid week. In short, anticyclonic flow centered over the
Great Basin slowly shifts southeastward becoming centered over Texas
by Thursday. Meanwhile, a cutoff low/inverted trough over Texas
shifts westward with time with the northern end of it tracking
across southern AZ. In the process, deeper moisture spreads over the
lower deserts (mainly near and east of the lower Colorado River
Valley). With the deeper moisture (most noticeable Wed and Thu),
storms that form over the higher terrain will have a better chance of
propagating over the lower deserts. However, there is apt to be a
fair amount of cloudiness around which can hinder destabilization.
Thus, we are not forecasting a big outbreak and PoPs reflect this.
Temperatures look to be at their warmest Tuesday (flirting with
Excessive Heat criteria near and west of the Lower Colorado River
Valley). With more clouds and humidity, temperatures trend down Wed
and Thu.
Friday through Monday...
During the upcoming weekend, as low pressure sets up along the
Pacific northwest coast, and as the high shifts further to the
southeast, the upper streamline fields and steering flow turn towards
the southwest over most of the area. This starts to bring in drier
air from the southwest and we can expect rain chances to diminish
from west to east with time. By Sunday afternoon, thunderstorm
chances look to be confined mostly to higher terrain areas east and
southeast of central Phoenix as skies become mostly sunny over the
central and western deserts. Little change Monday. Temperatures look
to remain reasonable.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL: The chance for
outflow wind gusts remain a possibility for the late afternoon, but
confidence on occurrence is low. The best chance for convection
remains in the higher terrain north and east of Phoenix. Sct to bkn
mid and high level clouds likely to persist through the period.
Otherwise, wind patterns should shift westerly in the afternoon and
then easterly in the early morning hours.
Southeast California/Southwest Arizona including KIPL and KBLH: Cigs
in a 10K-15K ft range will persist through this afternoon with some
clearing further to the south into Imperial County. Winds will be
more southwesterly in the afternoon through the evening with
possibility of a few gusts.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Thursday through Monday...Temperatures will continue to cool with
highs in the 100-110F range by Sunday. Monsoon moisture levels
continue to increase over the region with slight chances for
isolated afternoon thunderstorms. The best chances for convective
weather remains over the mountains in central and eastern Arizona.
Any storms that develop have the ability to produce lightning, gusty
winds, and wetting rains. Daytime relative humidities will drop to
15-25 percent but will have nighttime recoveries. Otherwise, winds
will be relatively normal in the 5 to 15 mph outside of any storm
influenced winds.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...AJ/CB
AVIATION...Deemer
FIRE WEATHER...Deemer
Area Forecast Discussion
National Weather Service Phoenix AZ
156 PM MST MON JUN 27 2016
.SYNOPSIS...
High pressure will move somewhat north and east of Arizona this week
allowing warm temperatures to prevail, but also bring a couple of
weather disturbances through the state. An increase in monsoon
moisture will accompany these weather systems providing a threat of
afternoon and evening showers and thunderstorms the remainder of
week.
&&
.DISCUSSION...
Rest of Today and Tonight...
A small upper low centered southwest of El Centro early this
afternoon continues moving westward. Shower activity associated with
it has been weak and isolated. Cloud cover associated with it has
been thinning. Stronger convection has begun to develop over the
higher terrain of northern and southeastern AZ due to destabilization
from surface heating. Storms over the northern half of AZ will also
benefit from some upper level diffluence. Hi-res models have been
depicting this. They are also in generally good agreement that
convection over our area this afternoon and tonight will be spotty.
In fact, they are not overly enthusiastic about southeast AZ. But
there are indications of outlflow moving through the south-central AZ
deserts (including Phoenix) from higher terrain late this
afternoon/early evening. With surface dew points in the low 50s and
being on the back side of the aforementioned upper low, it is not
surprising that the models are not depicting an active night for the
lower deserts. But still enough factors to keep slight chances going
(better chance over Zone 24). Also, with the southeasterly steering
flow, debris from Sonora could drift through late tonight.
Tuesday through Thursday...
There is relatively good model agreement on the evolution of the flow
pattern for mid week. In short, anticyclonic flow centered over the
Great Basin slowly shifts southeastward becoming centered over Texas
by Thursday. Meanwhile, a cutoff low/inverted trough over Texas
shifts westward with time with the northern end of it tracking
across southern AZ. In the process, deeper moisture spreads over the
lower deserts (mainly near and east of the lower Colorado River
Valley). With the deeper moisture (most noticeable Wed and Thu),
storms that form over the higher terrain will have a better chance of
propagating over the lower deserts. However, there is apt to be a
fair amount of cloudiness around which can hinder destabilization.
Thus, we are not forecasting a big outbreak and PoPs reflect this.
Temperatures look to be at their warmest Tuesday (flirting with
Excessive Heat criteria near and west of the Lower Colorado River
Valley). With more clouds and humidity, temperatures trend down Wed
and Thu.
Friday through Monday...
During the upcoming weekend, as low pressure sets up along the
Pacific northwest coast, and as the high shifts further to the
southeast, the upper streamline fields and steering flow turn towards
the southwest over most of the area. This starts to bring in drier
air from the southwest and we can expect rain chances to diminish
from west to east with time. By Sunday afternoon, thunderstorm
chances look to be confined mostly to higher terrain areas east and
southeast of central Phoenix as skies become mostly sunny over the
central and western deserts. Little change Monday. Temperatures look
to remain reasonable.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Much better chances for stronger east/northeast outflow winds are
likely late this afternoon, but confidence in timing is still
somewhat low. Actual storms may not survive to lower elevations,
though mountain obscuration, blowing dust, and frequent lightning for
arrivals/departures to the east may be problematic. Persistent
easterly winds this evening should occur earlier this normal. Sct to
bkn mid and high clouds should persist through Tuesday morning.
Southeast California/Southwest Arizona including KIPL and KBLH:
Cigs in a 10K-15K ft range will persist through this afternoon with
some gradual thinning of cloud cover tonight. Virga showers this
morning over the terminals are likely and should dissipate by around
noon. While a south to southeast sfc wind will be preferred through
this afternoon, winds will eventually become more southwesterly this
evening. A few stronger gusts may also be possible for brief
periods, especially this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday...
Temperatures will continue to "cool" with highs on Wednesday around
105-112F dropping into the 100-110F range by Sunday. As monsoon
moisture levels continue to increase over the region, isolated
thunderstorms are possible each afternoon/evening over much of the
desert southwest, with the highest chances over the higher terrain
of central and eastern Arizona. Accompanying any storm that develops
will be wetting rains, gusty erratic winds, and lightning. This
increase in moisture will support a rise in minimum humidities, with
values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...AJ/CB
AVIATION...Kuhlman
FIRE WEATHER...Hernandez
[top]
Area Forecast Discussion
National Weather Service Tucson AZ
155 PM MST MON JUN 27 2016
.SYNOPSIS...Expect scattered showers and thunderstorms into next
weekend. Daytime temperatures will be near normal or a few degrees
below normal, depending upon location.
&&
.DISCUSSION...The remnants of this mornings MCV was moving into
western Pima county as of 1:30 pm satellite imagery. Radar was
showing isolated storms mainly hugging the higher terrain S and E of
Tucson. Precipitable water values this afternoon ranged from 1" to
1.50". Isolated to scattered storms for the remainder of this
afternoon into this evening with a few showers possible overnight
associated with debris cloud cover.
Upper high that was over southern Utah this morning will drift to
the 4-corners area Tuesday and remain there until Wednesday. This
will result in a continued E-SE flow aloft over the area. Tuesday
will be a bit more active than today, especially across Sonora where
a weakening inverted trof, spun off the bigger one that is east of
the Texas Big Bend today, moves thru. Both 12z UofA WRF runs of the
NAM and GFS all show thunderstorm outflows Tuesday night pushing
into the Gulf thus setting up gulf surge of lower level moisture
into the lower deserts on Wednesday. Models indicating another weak
inverted trof will be passing through Sonora on Wednesday. We`ve
been advertising an uptick in areal coverage of storms on Wednesday
and that still looks on track. Will maintain scattered storms for
Thursday and Friday.
Both GFS and EC are hinting at drier westerly flow aloft late in the
weekend into early next week as the upper ridge axis sets up south
of the area. Enough residual moisture will be across the eastern
half of the forecast area for a chance of afternoon and evening
storms.
High temperatures will be around normal for most of the area during
the next 7 days.
&&
.AVIATION...VALID THRU 28/12Z.
Isolated to scattered -TSRA/-SHRA into this evening. Brief wind
gusts to near 40 kts and MVFR conditions due to reduced visibilities
will be possible with the stronger TSRA. Isolated -SHRA/-TSRA will
then occur late tonight into early Tuesday morning. Otherwise, cloud
decks generally ranging from 10k-15k ft msl, and surface wind
terrain driven mainly less than 12 kts. Aviation discussion not
updated for TAF amendments.
&&
.FIRE WEATHER...Scattered showers and thunderstorms will prevail
into next weekend. 20-foot winds today as well as Thursday through
Sunday will be terrain driven at less than 15 mph. 20-foot winds
Tuesday and Wednesday will generally be from the east to southeast at
5-15 mph with gusts of 15-20 mph.
&&
.CLIMATE...June rainfall at the Tucson airport currently stands at
0.32". This ranks as the 29th wettest June on record. Normal is 0.20"
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Phoenix AZ
940 AM MST MON JUN 27 2016
.SYNOPSIS...
High pressure will move somewhat north and east of Arizona this week
allowing warm temperatures to prevail, but also bring a couple of
weather disturbances through the state. An increase in monsoon
moisture will accompany these weather systems providing a threat of
afternoon and evening showers and thunderstorms the remainder of
week.
&&
.DISCUSSION...
A small upper level low is centered just southwest of Yuma this
morning. To the north of that is a larger anticyclonic circulation
centered over the Great Basin. A smaller anticyclone is centered over
north-central Mexico and to the east of that is a cutoff low centered
over Texas. The cyclonic feature over and near our forecast area has
been keeping weak isolated showers/sprinkles going this morning. Also
of note is a zone of strong east-to-west winds in the mid levels due
to gradient between the low and the high to the north. This weakens
as the day wears on. With 1000-700mb average mixing ratios of 7-8
g/kg, there is just enough moisture for CAPE - though there is still
CIN to contend with. But with decent CAPE over southeast AZ and
steering flow from the southeast later on, there is a non-zero chance
of storms surviving over the lower deserts. Not looking at a big day
at this point and hi-res models are not enthusiastic (except for NCAR
ensemble). One caveat is that upper level divergence (associated
with diffluence from the upper low) could extend further south over
our area instead of being focused over FGZ and VEF areas. That could
aid storm development (mainly over La Paz and northern Maricopa
Counties). No changes to the forecast at this time.
&&
.PREVIOUS DISCUSSION...Issued 310 am MST/PDT...
Early this morning a well defined inverted trof could be seen moving
westward across far southern/southwestern Arizona, and this feature
was clearly evident in vapor imagery as well as recent plot data.
Circulation around this feature was spreading increasing moisture
westward and into the desert west of Phoenix; latest blended total
precipitable water imagery indicated pwat values over 1.2 inches over
portions of the southwest deserts. The inverted trof created good
upper difluence across the central and western deserts and coupled
with a good uvv field, a field of mostly light showers could be seen
spreading into the western deserts at 2 am. As this inverted trof
slowly pushes west today we can expect a continued slight chance of
showers or thunderstorms across much of the lower deserts to the west
of Phoenix including portions of SE California. Later this afternoon
and evening across south central Arizona, the forcing becomes weaker
behind the exiting inverted trof but there is weak southeast steering
flow and sufficient deeper moisture and instability to allow for a
15-20 percent chance of mainly evening thunderstorms over the central
deserts and a chance of storms over higher terrain east of Phoenix.
This is supported by various mesoscale models such as the NMM6km.
Clouds and moisture working across the lower deserts will keep high
temps today mostly below the 110 degree mark, even over the far
western deserts.
Model guidance, including operational runs of the GFS and ECMWF, as
well as ensemble guidance such as the GEFS and NAEFS, continue to
call for a very monsoonal pattern to develop across the desert
southwest starting Tuesday and continuing through the end of the
work week. Initially the main upper high center forms near the four
corners, setting up a deeper southeast steering flow over most of
the area which will steadily transport increasing and deeper
moisture westward over the lower deserts. PWAT values steadily climb
and are forecast to exceed 1.5 inches across the main monsoon
moisture corridor which sets up just east of the lower Colorado
River Valley and extends into far eastern Arizona. The steering flow
is favorable to bring mountain storms into the lower deserts, and
from time to time there will be disturbances rotating around the
main upper high which will serve to enhance thunderstorm coverage
and intensity. Model guidance typically has a hard time with the
exact timing and track of these features and we generally cannot
place a lot of faith in them more than a day or two down the road.
Overall we are looking at a rather broad brushed forecast with 10-20
percent chances of mainly afternoon and evening storms over the
deserts mainly east of the lower CO river valley, and 30-40 percent
chances across the higher terrain east of Phoenix.
Later in the week the upper high starts to shift towards the
southeast and steering flow becomes more southerly. Still, moisture
remains high and in fact the GFS calls for PWAT value in the central
deserts to approach 2 inches later Thursday into Friday. This would
suggest a much better chance for heavy rains to accompany any storms
that develop. Of course, as moisture increases the temperatures will
fall off and by midweek high temps across south central Arizona will
approach and then fall below seasonal normals. It will stay a bit
hotter further west where the atmosphere is a bit drier, with highs
over 110 expected for much of the week.
During the upcoming weekend, as low pressure sets up along the
Pacific northwest coast, and as the high shifts further to the
southeast, the upper streamline fields and steering flow turn
towards the southwest over most of the area. This starts to bring in
drier air from the southwest and we can expect rain chances to
diminish from west to east with time. By Sunday afternoon,
thunderstorm chances look to be confined mostly to higher terrain
areas east and southeast of central Phoenix as skies become mostly
sunny over the central and western deserts.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Much better chances for stronger east/northeast outflow winds are
likely late this afternoon, but confidence in timing is still
somewhat low. Actual storms may not survive to lower elevations,
though mountain obscuration, blowing dust, and frequent lightning for
arrivals/departures to the east may be problematic. Persistent
easterly winds this evening should occur earlier this normal. Sct to
bkn mid and high clouds should persist through Tuesday morning.
Southeast California/Southwest Arizona including KIPL and KBLH:
Cigs in a 10K-15K ft range will persist through this afternoon with
some gradual thinning of cloud cover tonight. Virga showers this
morning over the terminals are likely and should dissipate by around
noon. While a south to southeast sfc wind will be preferred through
this afternoon, winds will eventually become more southwesterly this
evening. A few stronger gusts may also be possible for brief
periods, especially this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday...
Temperatures will continue to "cool" with highs on Wednesday around
105-112F dropping into the 100-110F range by Sunday. As monsoon
moisture levels continue to increase over the region, isolated
thunderstorms are possible each afternoon/evening over much of the
desert southwest, with the highest chances over the higher terrain
of central and eastern Arizona. Accompanying any storm that develops
will be wetting rains, gusty erratic winds, and lightning. This
increase in moisture will support a rise in minimum humidities, with
values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...AJ
PREVIOUS DISCUSSION...CB
AVIATION...Kuhlman
FIRE WEATHER...Hernandez
Area Forecast Discussion
National Weather Service Flagstaff AZ
938 AM MST MON JUN 27 2016
.SYNOPSIS...Expect scattered showers and thunderstorms today along
and south of the Mogollon Rim, and isolated storms elsewhere.
Strong, gusty winds are possible near any storms. Beginning
Tuesday, monsoonal moisture is forecast to increase across all of
northern Arizona leading to daily chances for showers and
thunderstorms through the week.
&&
.Discussion...The 12Z sounding showed a steady increase in PW from
yesterday morning (0.59 vs 0.44) with an easterly steering flow of
around 15 MPH today. There is also a slight cap at just above 500 mb
(around 20kft msl). Surface dew points in the 40s have pushed all the
way to Page this morning. Some cloud cover today will slow surface
heating. These two factors will slow convection by an hour or two.
In any case, expect convection to start over much of the area by
early afternoon.
&&
.PREV DISCUSSION /400 AM MST...
Moisture is increasing across central and eastern AZ this morning
per satellite PW estimates and sfc dew point data. The highest PW
values should remain along and south of I-40 today, while shallow
sfc moisture has made it as far north as Page this morning. Thus
scattered showers and thunderstorms are expected this afternoon
and evening along the Mogollon Rim from Happy jack eastward with
isolated storm coverage elsewhere. Most of the storms will be
high based, with strong outflow winds probable from them.
Storm motion today from east to west.
On Tuesday, high pressure aloft will become centered near the
Four Corners. We will see a moist easterly flow Tuesday that
transitions to a moist southerly wind around the middle of the
week. This will draw deeper moisture into the region leading to
increasing chances for showers and thunderstorms across all of
northern Arizona. Expect better chances for measurable rainfall
starting Wednesday. This moisture is expected to remain in place
through at least Saturday bringing daily chances for showers and
thunderstorms.
&&
.AVIATION...For the 18Z Package...Scattered TSRA will develop from
KFLG - KRQE south this afternoon and evening with isolated TSRA
possible elsewhere. Gusty winds near 40 kts and moderate rain
possible in storms. Otherwise, expect VFR conditions. Activity
decreasing aft 06Z though a few showers may continue overnight.
Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...An increase in moisture will lead to scattered
thunderstorms from the Mogollon Rim to the Chuska Mountains south
this afternoon and evening. Isolated storms are possible elsewhere.
Storm motion will be from east to west today. Moisture increases
into Tuesday with scattered storms expected. Storm motion becomes
more south to north on Tuesday. Expect erratic and gusty winds near
any showers and storms.
Wednesday through Friday...An active wet Monsoon weather pattern is
expected with scattered showers and thunderstorms each day across
northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MAS/DL
AVIATION...MCS
FIRE WEATHER...MCS
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Flagstaff AZ
938 AM MST MON JUN 27 2016
.SYNOPSIS...Expect scattered showers and thunderstorms today along
and south of the Mogollon Rim, and isolated storms elsewhere.
Strong, gusty winds are possible near any storms. Beginning
Tuesday, monsoonal moisture is forecast to increase across all of
northern Arizona leading to daily chances for showers and
thunderstorms through the week.
&&
.Discussion...The 12Z sounding showed a steady increase in PW from
yesterday morning (0.59 vs 0.44) with an easterly steering flow of
around 15 MPH today. There is also a slight cap at just above 500 mb
(around 20kft msl). Surface dew points in the 40s have pushed all the
way to Page this morning. Some cloud cover today will slow surface
heating. These two factors will slow convection by an hour or two.
In any case, expect convection to start over much of the area by
early afternoon.
&&
.PREV DISCUSSION /400 AM MST...
Moisture is increasing across central and eastern AZ this morning
per satellite PW estimates and sfc dew point data. The highest PW
values should remain along and south of I-40 today, while shallow
sfc moisture has made it as far north as Page this morning. Thus
scattered showers and thunderstorms are expected this afternoon
and evening along the Mogollon Rim from Happy jack eastward with
isolated storm coverage elsewhere. Most of the storms will be
high based, with strong outflow winds probable from them.
Storm motion today from east to west.
On Tuesday, high pressure aloft will become centered near the
Four Corners. We will see a moist easterly flow Tuesday that
transitions to a moist southerly wind around the middle of the
week. This will draw deeper moisture into the region leading to
increasing chances for showers and thunderstorms across all of
northern Arizona. Expect better chances for measurable rainfall
starting Wednesday. This moisture is expected to remain in place
through at least Saturday bringing daily chances for showers and
thunderstorms.
&&
.AVIATION...For the 18Z Package...Scattered TSRA will develop from
KFLG - KRQE south this afternoon and evening with isolated TSRA
possible elsewhere. Gusty winds near 40 kts and moderate rain
possible in storms. Otherwise, expect VFR conditions. Activity
decreasing aft 06Z though a few showers may continue overnight.
Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...An increase in moisture will lead to scattered
thunderstorms from the Mogollon Rim to the Chuska Mountains south
this afternoon and evening. Isolated storms are possible elsewhere.
Storm motion will be from east to west today. Moisture increases
into Tuesday with scattered storms expected. Storm motion becomes
more south to north on Tuesday. Expect erratic and gusty winds near
any showers and storms.
Wednesday through Friday...An active wet Monsoon weather pattern is
expected with scattered showers and thunderstorms each day across
northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MAS/DL
AVIATION...MCS
FIRE WEATHER...MCS
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Tucson AZ
930 AM MST MON JUN 27 2016
.SYNOPSIS...Expect scattered showers and thunderstorms into next
weekend. Daytime temperatures will be near normal or a few degrees
below normal, depending upon location.
&&
.DISCUSSION...Debris cloud cover over the area as of 9 am with
embedded light showers/sprinkles. Visible imagery showed a weak MCV
over NE Pima county, moving slowly to the west. Upper air maps this
morning placed upper high over southern Utah with easterly flow over
the area. The Tucson morning sounding still holding with 1.40" PW
with values across the area, based on various sources, ranged from
1" to 1.50".
12z UofA WRF NAM focusing isolated to scattered convection this
afternoon mostly S and E of Tucson. HRRR still playing catch-up as
the 14z run didn`t have any of the shower activity across southern
Tucson between 8-9 am.
All signs point to a ramp up in areal coverage of storms from
Wednesday on.
&&
.AVIATION...VALID THRU 28/12Z.
Isolated -SHRA will prevail thru 18Z this morning, then isolated to
scattered -TSRA/-SHRA this afternoon and evening. Brief wind gusts
to near 40 kts and MVFR conditions due to reduced visibilities will
be possible with the stronger TSRA. Isolated -SHRA/-TSRA will then
occur late tonight into early Tuesday morning. Otherwise, cloud
decks generally ranging from 10k-15k ft msl, and surface wind
terrain driven mainly less than 12 kts. Aviation discussion not
updated for TAF amendments.
&&
.FIRE WEATHER...Scattered showers and thunderstorms will prevail
into next weekend. 20-foot winds today as well as Thursday through
Sunday will be terrain driven at less than 15 mph. 20-foot winds
Tuesday and Wednesday will generally be from the east to southeast at
5-15 mph with gusts of 15-20 mph.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
AREA FORECAST DISCUSSION
National Weather Service San Diego CA
138 PM PDT MON JUN 27 2016
.SYNOPSIS...
High pressure aloft will continue hot weather for inland areas
through Wednesday followed by slow cooling into next weekend as
high pressure aloft weakens and a weak trough of low pressure
develops over the Pacific Northwest. Mid and high level moisture
associated with a disturbance moving through the region will
bring a slight chance of afternoon and early evening thunderstorms
with gusty winds through Wednesday, mainly near the mountains.
The marine layer and onshore flow will keep coastal high
temperatures cooler with areas of night and morning low clouds and
fog.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Visible and radar imagery continues to show mid and high level
clouds and some light radar returns associated with an easterly
wave which is moving through the region. Most of the fast moving
light radar returns are resulting in virga or sprinkles. However,
a band of stationary showers has developed and persisted on the
desert slopes near Lake Arrowhead over the past hour. The 12Z
Miramar sounding shows precipitable water having increased to 1.48
inches, although the majority of the moisture appears to be above
700 mb, with a dry layer noted below 700 mb until you reach the 10
deg C marine layer inversion near 1000 ft MSL. It is due to the
dry layer below 700 mb that most of the precipitation may
evaporate before reaching the ground, which is why most of it will
appear as virga or maybe some sprinkles. The amount of cloud
cover we have today, and which locations receive more sunlight
than others, is playing a factor in how hot we get today. Due to
the mid and high clouds, temperatures have been slightly reduced
at 1 pm today compared to 1 pm yesterday in the Inland Empire, all
mountain areas, the High Deserts and Coachella Valley. However,
with some higher surface dewpoints in the area (low 60s shown
currently over most coast, valley and desert areas), it will feel
more muggy and uncomfortable.
Despite the increase in moisture and the wave moving overhead, the
elevated instability parameters shown by the forecast models for
this afternoon and evening are still not impressive. Also, the
strong easterly flow is not conducive for thunderstorms that
develop over the mountains to maintain their structure. Thus, the
latest HRRR run shows some light shower activity but not much in
the way of thunderstorm activity this afternoon. Nevertheless,
slight chance for thunderstorms remains in the forecast today for
the mountains, with some activity possibly being blown west into
the valleys.
Meanwhile, marine layer stratus along the coast this morning was
able to clear pretty quickly, but has since re-developed along the
immediate coast, likely due to the decently strong marine layer
inversion.
Models show drier air intruding into Southern California Tuesday
and Wednesday as flow turns southerly in the wake of the easterly
wave, resulting in less of a chance for afternoon and early
evening mountain thunderstorms on those days. However, the
clearer skies and strong ridge over the four corners region should
result in hotter conditions, with highs 5-10 degrees above normal.
Continued hot for inland areas on Wednesday, with 850 mb
temperatures in the deserts reaching 27-29 deg C, and near 26-27
deg C in the valleys. A Heat Advisory continues for the deserts,
mountains and valleys through Wednesday. Despite the ridge
weakening on Thursday, looks like the 850 mb temperatures do not
decrease too much, so hot conditions may continue.
Cooler Friday into the weekend as a trough moves into the Pacific
Northwest, with a deepening of the marine layer as well, resulting
in night and morning stratus into the coast and portions of the
valleys.
&&
.AVIATION...
271950Z...Coast/Valleys...Areas of sct-bkn clouds based 800-1200
feet MSL with tops around 1500 ft MSL over the coastal waters
otherwise mostly clear. After 28/0z this evening low clouds bkn-
ovc based 800-1200 feet MSL with tops around 1500 ft MSL will push
inland about 15 miles with local visibilities 2-4 miles along higher
coastal terrain/mesas. There is a moderate risk that the coastal low
clouds will again be patchy so the confidence is low on the timing
and duration of the bkn low clouds at KSAN tonight. Some low clouds
may temporarily move in on the sea breeze but will leave out of the
KSAN TAF.
Isolated SHRA/TSRA near the mountains through 28/00z this afternoon
with CB bases near 9000 ft MSL and tops to near 35000 ft MSL.
Mountains and Deserts...Sct-bkn clouds based around 9000 feet MSL
with unrestricted visibilities. This afternoon through 28/00Z
isolated SHRA/TSRA with cloud bases 9000 ft MSL and tops to
35000 ft MSL will be possible over the mountains.
&&
.MARINE...
100 pm...No hazardous marine weather is expected through Friday.
&&
.BEACHES...
100 pm...The long period south swell will continue to decrease, but
3-5 foot surf will continue on the southwest facing beaches through
tonight. The surf will lower to 2 to 4 feet Tuesday. Another long-
period south swell from 200 degrees will bring 4-7 foot surf to
southwest facing beaches late Wednesday and Thursday along with
dangerous rip currents.
&&
.FIRE WEATHER...
Slight chance of dry lightning over the mountains and portions of
the valleys this afternoon and evening, as an easterly wave moves
through the region. Drying will start to take place Tuesday, with
maybe just enough moisture leftover on Tuesday and Wednesday to
produce isolated afternoon thunderstorms over the mountains.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX Watches/Warnings/Advisories...
CA...Heat Advisory until 8 PM PDT Wednesday for Apple and Lucerne
Valleys-Coachella Valley-Riverside County Mountains-San
Bernardino County Mountains-San Bernardino and Riverside
County Valleys-The Inland Empire-San Diego County Deserts-
San Diego County Mountains-San Gorgonio Pass Near Banning.
PZ...None.
&&
$$
PUBLIC/FIRE WEATHER...Harrison
AVIATION/MARINE...Small
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
309 PM CDT MON JUN 27 2016
.SHORT TERM...(This Evening through Tuesday)
Issued at 309 PM CDT MON JUN 27 2016
A broad upper level trough was located across the upper Great
Lakes and will amplify as it digs southeast across lower MI. The
upper flow will become more northwesterly and a short-wave trough
across eastern WY and will translate southeast across western NE
into central KS by the mid morning hours of Tuesday.
A weak front extend from central IA, southwest into south central
NE, then recurved northwest into the NE PNHDL. There may be enough
surface convergence ahead of the surface front across southeast NE
for isolated to scattered thunderstorms to develop late this
afternoon or early evening. The HRRR model seems to have a handle on
the thunderstorms developing across southwest IA, and shows
thunderstorms developing southwest ahead of the weak surface
boundary, and then moving southeast across much of northeast KS. If
thunderstorms manage to develop across southern NE, they will then
move southeast into the northern counties of the CWA. MLCAPE will be
around 3,000 J/kg and the 0-6 KM effective shear will be 30 KTS.
Therefore, any isolated thunderstorms late this afternoon and early
evening across the northern counties of the CWA may be strong to
severe with the primary hazard being large hail and damaging wind
gusts. If thunderstorms do develop along the weak front late this
afternoon and early evening they should weaken and dissipate through
the mid evening hours.
Tonight, The mesoscale models are showing two thunderstorm complexes
developing across the high plains of eastern CO and western NE. Most
numerical models show these thunderstorm complexes moving south-
southeast across western and central KS, remaining just west of the
CWA. However, the NMM and GFS show the northern thunderstorm complex
that develops across the western NE panhandle, moving southeast
across northwest KS into the western counties of the CWA between 12Z
and 15Z TUE. If an MCS manages to develop it may be able to maintain
itself due the sufficient MUCAPE and vertical windshear. An MCS may
bring the threat for damaging wind gusts to north central KS near
sunrise through the mid morning hours of Tuesday.
Tuesday, after the potential for morning thunderstorms across north
central KS, skies will become partly cloudy. It looks dry for the
remainder of the day. Upslope flow across the higher terrain of
northeast CO, eastern WY and the western NE panhandle will cause
scattered thunderstorms to develop and these storms will organize
into an MCS late Tuesday afternoon across the central high plains.
Highs Tuesday afternoon will reach the mid to upper 80s.
.LONG TERM...(Tuesday Night through Monday)
Issued at 309 PM CDT MON JUN 27 2016
In general, chances for precip remain in the forecast through the
extended period as models continue to show a conditionally
unstable airmass with possible pertibations within the flow.
Although confidence in storms occurring at any give time are below
normal as the forecast should be driven primarily by mesoscale
features, and thunderstorms in one period could affect the next
couple periods.
For Tuesday night through Thursday, the better chances for
thunderstorms looks to be Wednesday or Wednesday night as there
continues to be signs for a vort max to move through northwest
flow aloft. However there are timing differences with vort max as
well as with the location of a possible convective system among
the various solutions. Because of this, POPs where kept in the 30
to 50 percent range. Models continue to support temps a little
closer to or below normal temps with highs in the lower and mid
80s and lows in the mid 60s.
For Thursday night through the weekend, the ECMWF and GFS are
showing a little better defined cold front moving into the area
and stalling out across east central or southern KS as the
synoptic pattern becomes a little less amplified and flow aloft
becomes a little more westerly. Since there is not a big change in
airmass with the front pushing through well south of the forecast
area, potential instability remains possible with disturbances
coming off the Rockies. Therefore it is difficult to rule out
precip chances through this period as well. The reenforcement of
surface ridging should keep highs in the lower and mid 80s and
lows in the mid 60s through the weekend.
By next Monday, there are indications for shortwave ridging to
develop over the central plains and the thermal ridge to build
back in from the southwest. With no obvious forcing seen in the
models, have trended POPs into the slight chance and temps should
be warming up again with some lower 90s possible.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1238 PM CDT MON JUN 27 2016
Scattered CU will develop at the terminals with bases of 4,000 to
6,000 feet. There may be an thunderstorm around the terminals late
this afternoon or this evening. High clouds from a thunderstorm
complex moving southeast across central KS will probably prevent
ground fog from forming by sunrise. However, if skies remain clear
there could be some patchy dense ground fog around the terminals near
sunrise Tuesday morning.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...Wolters
AVIATION...Gargan