Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/28/16
Area Forecast Discussion
National Weather Service Phoenix AZ
730 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...
The most pronounced shortwave has progressed towards the southern CA
coast this evening, however strongly difluent jet level flow has
supported larger scale ascent through much of northern and central
AZ. 21Z KPSR sounding data sampled a well mixed sfc-650mb boundary
layer with moisture solidly at 8 g/kg. Meanwhile, 00Z KTWC sounding
was slightly better with 9 g/kg; and prevailing SE flow was
advecting this moisture profile towards steeper lapse rates and
better dynamics. While notable Cinh was evident in objective
analysis, outflow boundaries descending from higher elevations have
been sufficiently deep to invigorate new deep convection. This has
yielded gusts as high as 35mph and localized dense blowing dust.
Activity through western AZ may be meeting the end of its life cycle
shortly as a more abrupt instability gradient exists along the
Colorado River. Meanwhile, new activity forced along a boundary and
orographics through SE Pinal County may enhance deeper outflow and
enhance isolated development in higher terrain of NE Pinal County
while also creating a dust problem at lower elevations. Have
adjusted some pops for current radar trends and further adjustments
may be necessary going through the evening.
&&
.PREVIOUS DISCUSSION...
/156 PM MST MON JUN 27 2016/
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:
Lower confidence forecast as several competing outflow boundaries
will create frequent wind shifts through the evening, before
settling on a predominant easterly direction overnight. There is a
fairly low chance of blowing dust making it into the Phoenix
terminals and lesser chance of actual storms impacting the terminal
sites. Easterly sfc winds should prevail much longer into the late
afternoon Tuesday than is typical.
Southeast California/Southwest Arizona including KIPL and KBLH:
Wind shifts will be the main forecast challenge in SE CA through
tonight as outflow boundaries move into the region from AZ. Brief
gusts will be possible at KBLH, but likely minimal impact at KIPL.
Periods of variability in sfc winds will be likely overnight, then
favor a southerly component Tuesday afternoon. Periodic cloud decks
12K-15K ft will be common across the region.
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...MO/AJ/CB
AVIATION...MO
FIRE WEATHER...Deemer
Area Forecast Discussion
National Weather Service Phoenix AZ
730 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...
The most pronounced shortwave has progressed towards the southern CA
coast this evening, however strongly difluent jet level flow has
supported larger scale ascent through much of northern and central
AZ. 21Z KPSR sounding data sampled a well mixed sfc-650mb boundary
layer with moisture solidly at 8 g/kg. Meanwhile, 00Z KTWC sounding
was slightly better with 9 g/kg; and prevailing SE flow was
advecting this moisture profile towards steeper lapse rates and
better dynamics. While notable Cinh was evident in objective
analysis, outflow boundaries descending from higher elevations have
been sufficiently deep to invigorate new deep convection. This has
yielded gusts as high as 35mph and localized dense blowing dust.
Activity through western AZ may be meeting the end of its life cycle
shortly as a more abrupt instability gradient exists along the
Colorado River. Meanwhile, new activity forced along a boundary and
orographics through SE Pinal County may enhance deeper outflow and
enhance isolated development in higher terrain of NE Pinal County
while also creating a dust problem at lower elevations. Have
adjusted some pops for current radar trends and further adjustments
may be necessary going through the evening.
&&
.PREVIOUS DISCUSSION...
/156 PM MST MON JUN 27 2016/
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:
Lower confidence forecast as several competing outflow boundaries
will create frequent wind shifts through the evening, before
settling on a predominant easterly direction overnight. There is a
fairly low chance of blowing dust making it into the Phoenix
terminals and lesser chance of actual storms impacting the terminal
sites. Easterly sfc winds should prevail much longer into the late
afternoon Tuesday than is typical.
Southeast California/Southwest Arizona including KIPL and KBLH:
Wind shifts will be the main forecast challenge in SE CA through
tonight as outflow boundaries move into the region from AZ. Brief
gusts will be possible at KBLH, but likely minimal impact at KIPL.
Periods of variability in sfc winds will be likely overnight, then
favor a southerly component Tuesday afternoon. Periodic cloud decks
12K-15K ft will be common across the region.
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...MO/AJ/CB
AVIATION...MO
FIRE WEATHER...Deemer
[top]
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.
&&
$$
PUBLIC.......MAS
AVIATION.....RR
FIRE WEATHER...RR
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Flagstaff AZ
340 PM MST MON JUN 27 2016
.SYNOPSIS...Daily showers and thunderstorms will increase across
norther Arizona this week as a deep moist southerly flow developes
across the state. Strong, gusty winds are possible near any storms
along with heavy rain and lightning.
&&
.Discussion...Showers and thunderstorms increase across our CWA this
afternoon. The least activity is over northwest Coconino County
this afternoon.
The center of the high pressure will migrate over far northwest New
Mexico by Tuesday. This will bring a deep and moist southeast to
south flow over Arizona. This lead to increasing chances for showers
and thunderstorms each day across all of northern Arizona. Expect
better chances for measurable rainfall starting Wednesday. This
moisture is expected to remain in place through at least Saturday
bringing daily chances for showers and thunderstorms.
&&
.AVIATION...For the 00Z Package...Isolated to scattered TSRA are
expect to continue through 06Z Tue. Gusty winds near 40 kts and
moderate rain are possible in storms. A few showers may continue
overnight, with best chances for this in Coconino and Yavapai
Counties. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...An active monsoon pattern in place across northern
Arizona will cause daily rounds of scattered showers and
thunderstorms. Storm motion will generally be from the south to
north. Expect erratic and gusty winds near showers and storms.
Thursday through Saturday...An active and wet Monsoon weather
pattern will continue with scattered showers and thunderstorms each
day across northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.......MAS
AVIATION.....RR
FIRE WEATHER...RR
For Northern Arizona weather information visit
weather.gov/flagstaff
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 Northern Indiana
143 PM EDT SUN JUN 26 2016
.SYNOPSIS...
Issued at 525 AM EDT Sun Jun 26 2016
Chances for showers and thunderstorms will increase from west to
east today as an upper level system moves into the area. Isolated
wind gusts greater than 50 mph and heavy rain will be the main
threats with thunderstorms this afternoon and early this evening.
Highs today will be near 90 with heat indices rising to near 100
degrees this afternoon. A drier and eventually cooler weather
pattern will then settle in for much of next week.
&&
.SHORT TERM...(Today and Tonight)
Issued at 520 AM EDT Sun Jun 26 2016
Very warm and humid air will spread northeast into the forecast area
today. Have issued a heat advisory for most of northern Indiana
until 6 pm EDT given a very warm start with early morning
temperatures in the 70s and given very humid air just upstream. Some
clouds may hinder the warmup today, but the heat index over much of
northern Indiana should rise to around 100 degrees later today.
A large area of thunderstorms extended across Iowa into Wisconsin
early this morning ahead of an upper trof. These storms will move
east later today. Wind directions in the lower atmosphere should be
relatively unidirectional and wind speed under 30 knots. Mid level
lapse rates will be relatively stable, close to 6.0C/Km. CAPE values
should rise to between 1500 and 2000 J/Kg per latest BUFKIT high
resolution soundings. Given favorable diurnal timing, some storms
will likely become strong and produce wind gusts in excess of 50
mph. Precipitable water values should climb above 2.0 inches so
heavy rainfall may cause localized flooding.
&&
.LONG TERM...(Monday through Saturday)
Issued at 520 AM EDT Sun Jun 26 2016
An upper level trof is expected to amplify this upcoming week and
bring dry and relatively cool weather to the area during the middle
of the week. The cold front should move across the area late Monday.
Lakeshore hazards along the southeast shore of Lake Michigan are
likely Monday night into Tuesday as winds become northwest behind
the front. Cooler weather will return during the middle of the week
as the long wave trof becomes established over eastern North
America. Lows should dip well into the 50s Tuesday night. Highs
should be in the 70s to around 80 from Tuesday through the end of
the week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 142 PM EDT Sun Jun 26 2016
Vfr conds xpcd through the pd. Prefntl trough in assocn/w sw
trough swirling through wrn ON stretching fm wrn lwr MI swwd
through wrn IL cont ewd through the aftn. Stabilization in wake of
morning outflw throws some uncertainty into how things redvlp
this aftn alg prefntl trough. Hwvr enough of concensus projection
of fvrd placement exists to drop prior tempo tsra grouping at
KSBN. While environmental flw through base of mid lvl trough
remains weak...rapidly destabilizing outflw bubble w/swd extent and
somewhat enhanced sfc convergence xpcd invof KFWA lt this aftn.
RAP UH progs suggests a fairly stg line of convn likely to result
this evening acrs ern IN/wrn OH which may yield a brief pd of
+tsra w/potential mvfr conds resulting. Will cont to monitor.
&&
.IWX Watches/Warnings/Advisories...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...Skipper
SHORT TERM...Skipper
LONG TERM...Skipper
AVIATION...T
Visit us at www.weather.gov/iwx
Follow us on Facebook...Twitter...and YouTube at:
www.facebook.com/NWSNorthernIndiana
www.twitter.com/nwsiwx
www.youtube.com/NWSNorthernIndiana
Area Forecast Discussion
National Weather Service Indianapolis IN
1235 PM EDT SUN JUN 26 2016
.UPDATE...
The AVIATION Section has been updated below.
&&
.SYNOPSIS...
Issued at 400 AM EDT Sun Jun 26 2016
A frontal system will move through the area this afternoon and
tonight, bringing thunderstorms to portions of the area. An
isolated severe storm cannot be ruled out, but a widespread severe
threat is unlikely. Heat indices in the very humid airmass will
approach 100 degrees at times this afternoon. A secondary cold
front will bring relief from the heat Monday night into Tuesday as
high pressure builds into the area behind it. Dry conditions will
dominate much of the week, with low precipitation chances
returning as next weekend arrives.
&&
.NEAR TERM /Rest of Today/...
Issued at 955 AM EDT Sun Jun 26 2016
.update...Continue to slow down the arrival time storms with isolated storms
by early afternoon and the best chances being 6 PM an beyond based on current
trends and HRR. Tweaked Highs down a degree over the northwest half of our region
due to increasing clouds. Otherwise...the rest of the near term is on track and no
updates other than grids are needed at this time.
Previous near term discussion follows....
Thunderstorm chances will steadily increase through the day as the
cold front approaches. While ample instability will be present
owing to the very warm and humid airmass ahead of the front, shear
is meager at best. Suppose the significant instability could
produce a pulse severe storm here or there, but do not expect
anything more than that. Hydrologic issues may be the more
pressing concern as precipitation efficiency should be quite high
with deep warm cloud owing to a freezing level pushing 14kft,
pseudotropical with very deep saturation, and storm motions which
are likely to be somewhat slow contributing to the potential for
some heavy rainfall. Additionally, observed rainfall in the last
week or two has been roughly 150 to as much as 400 percent of
normal in some portions of central Indiana. Will hit the flood
threat in the HWO.
Consensus temperatures looked reasonable with minor upward tweaks
where storms are expected to arrive latest in the day, mainly
south and southeast. Maximum heat index values will likely
approach and may briefly exceed 100 degrees across portions of the
area this afternoon. Indices should remain below advisory criteria
but will be mentioned in the HWO as this will be one of the hotter
days of the year thus far.
&&
.SHORT TERM /Tonight through Tuesday Night/...
Issued at 400 AM EDT Sun Jun 26 2016
Storm threat will persist into the evening across much of the area
and the overnight for at least portions of central Indiana. Again,
while an isolated pulse severe storm cannot be ruled out, think
sporadic hydrologic issues will be the more likely threat to
require monitoring. As the front exits the area late tonight into
early Monday morning, will rapidly taper off precip chances with
only the far southern area carrying a slight chance into the first
few hours of the day on Monday. The remainder of the short term
looks dry, although will have to monitor secondary cold frontal
passage Monday night into Tuesday as dewpoints will still be in
the 60s ahead of it.
Consensus temperatures appeared632 reasonable with minor tweaks
throughout the period, mainly late in the period.
&&
.LONG TERM /Wednesday through Saturday/...
Issued at 241 AM EDT Sun Jun 26 2016
Models and ensembles in good agreement that Canadian high pressure
will allow for dry weather with slightly below normal temperatures
through Thursday. Then, an upper trough will pivot east across the
Great Lakes and push a back door cold front across central Indiana
early next weekend. Regional blend suggests there could be a few
showers and thunderstorms around over all or parts of the area
starting Thursday night and continuing through Saturday, when the
front will likely move through. Temperatures should bounce back to
near normal with highs in the lower to mid 80s by Thursday or
Friday. Look for lows in the 50s Wednesday night and the 60s the
rest of the long term.
&&
.AVIATION /Discussion for 261800Z TAF Issuance/...
Issued at 1235 PM EDT Sun Jun 26 2016
VFR conditions expected throughout the period with the exception
of restrictions within convection later this afternoon and
evening.
Skies remain mostly sunny early this afternoon with light
southwest winds doing little to deter the muggy airmass over the
region. Cold front remains northwest of central Indiana currently
with a remnant outflow boundary from overnight storms in the upper
Midwest noted on satellite and radar over the northern Wabash
Valley. This feature may serve as the initial catalyst to fire
convection as it drops further into the forecast area over the
next few hours. With little shear and forcing aloft present
however...expect storms remain isolated to widely scattered
through about 21Z. A continued VCTS mention will suffice at all
sites. Will highlight SW winds veering to westerly by early
evening...but likely to see variable wind direction for a period
of time once the outflow passes.
Hi-res guidance continues to develop a broken line of convection
with the front for late afternoon and evening. Confidence is
higher in greater threat for convective impacts at all terminals
during this period and despite some question as to how extensive
storm coverage will eventually become in the absence of greater
shear...feel a 4 hour tempo group for storms producing brief
restrictions is prudent at all sites.
Any lingering convection will move south of the terminals with the
front overnight. A brief period of mid to high level clouds will
give way to mainly clear skies on Monday as deep subsidence
spreads into the region on N/NW winds.
&&
.IND Watches/Warnings/Advisories...NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/MK/JH
SHORT TERM...NIELD
LONG TERM...MK
AVIATION...RYAN
Area Forecast Discussion
National Weather Service Indianapolis IN
1012 AM EDT SUN JUN 26 2016
.UPDATE...
The AVIATION section has been updated below.
&&
.SYNOPSIS...
Issued at 400 AM EDT Sun Jun 26 2016
A frontal system will move through the area this afternoon and
tonight, bringing thunderstorms to portions of the area. An
isolated severe storm cannot be ruled out, but a widespread severe
threat is unlikely. Heat indices in the very humid airmass will
approach 100 degrees at times this afternoon. A secondary cold
front will bring relief from the heat Monday night into Tuesday as
high pressure builds into the area behind it. Dry conditions will
dominate much of the week, with low precipitation chances
returning as next weekend arrives.
&&
.NEAR TERM /Rest of Today/...
Issued at 955 AM EDT Sun Jun 26 2016
.update...Continue to slow down the arrival time storms with isolated storms
by early afternoon and the best chances being 6 PM an beyond based on current
trends and HRR. Tweaked Highs down a degree over the northwest half of our region
due to increasing clouds. Otherwise...the rest of the near term is on track and no
updates other than grids are needed at this time.
Previous near term discussion follows....
Thunderstorm chances will steadily increase through the day as the
cold front approaches. While ample instability will be present
owing to the very warm and humid airmass ahead of the front, shear
is meager at best. Suppose the significant instability could
produce a pulse severe storm here or there, but do not expect
anything more than that. Hydrologic issues may be the more
pressing concern as precipitation efficiency should be quite high
with deep warm cloud owing to a freezing level pushing 14kft,
pseudotropical with very deep saturation, and storm motions which
are likely to be somewhat slow contributing to the potential for
some heavy rainfall. Additionally, observed rainfall in the last
week or two has been roughly 150 to as much as 400 percent of
normal in some portions of central Indiana. Will hit the flood
threat in the HWO.
Consensus temperatures looked reasonable with minor upward tweaks
where storms are expected to arrive latest in the day, mainly
south and southeast. Maximum heat index values will likely
approach and may briefly exceed 100 degrees across portions of the
area this afternoon. Indices should remain below advisory criteria
but will be mentioned in the HWO as this will be one of the hotter
days of the year thus far.
&&
.SHORT TERM /Tonight through Tuesday Night/...
Issued at 400 AM EDT Sun Jun 26 2016
Storm threat will persist into the evening across much of the area
and the overnight for at least portions of central Indiana. Again,
while an isolated pulse severe storm cannot be ruled out, think
sporadic hydrologic issues will be the more likely threat to
require monitoring. As the front exits the area late tonight into
early Monday morning, will rapidly taper off precip chances with
only the far southern area carrying a slight chance into the first
few hours of the day on Monday. The remainder of the short term
looks dry, although will have to monitor secondary cold frontal
passage Monday night into Tuesday as dewpoints will still be in
the 60s ahead of it.
Consensus temperatures appeared632 reasonable with minor tweaks
throughout the period, mainly late in the period.
&&
.LONG TERM /Wednesday through Saturday/...
Issued at 241 AM EDT Sun Jun 26 2016
Models and ensembles in good agreement that Canadian high pressure
will allow for dry weather with slightly below normal temperatures
through Thursday. Then, an upper trough will pivot east across the
Great Lakes and push a back door cold front across central Indiana
early next weekend. Regional blend suggests there could be a few
showers and thunderstorms around over all or parts of the area
starting Thursday night and continuing through Saturday, when the
front will likely move through. Temperatures should bounce back to
near normal with highs in the lower to mid 80s by Thursday or
Friday. Look for lows in the 50s Wednesday night and the 60s the
rest of the long term.
&&
.AVIATION /Discussion for the 261500Z TAF Update/...
Issued at 1012 AM EDT Sun Jun 26 2016
TAFs are in decent shape for the mid morning update and only making
subtle adjustments. Main change is to slow initial VCTS mention by
an hour or two this afternoon. Already seeing a few showers develop
in the warm humid airmass...but current hi-res guidance favors
isolated convection developing primarily after 17-18Z with more
substantial convection associated with the cold front set to impact
the terminals late afternoon and evening.
12Z discussion follows.
Good confidence in VFR conditions through much of the period except
MVFR and possibly IFR at times in thunderstorms. The first batch of
convection should move into the LAF and HUF areas after 14z and IND
and BMG after 15z as a warm front moves across the area. Then, a
more solid line will be dropping southeast over the terminals 21z
and later this afternoon near and just ahead of an approaching cold
front per the HRRR. The HRRR is currently handling the convection
rather well. Things will be winding down tonight after the cold
front moves through.
Winds will be south and southwest today and increase to around 10
knots 14z-16z. Winds near term will then become west and northwest 7
knots or less post frontal tonight.
&&
.IND Watches/Warnings/Advisories...NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/MK/JH
SHORT TERM...NIELD
LONG TERM...MK
AVIATION...MK/RYAN
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
646 PM CDT MON JUN 27 2016
...Update to aviation forecast discussion...
.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 00Z TAFS through 00Z Tuesday Evening)
Issued at 646 PM CDT MON JUN 27 2016
Outflow boundary from storms initially in SE Nebraska continues
to generate additional convection as it moves south and west
into the area. Will go ahead with VCTS and outflow winds in the
very near term but coverage and persistence of convection has not
been consistent. Will need to watch wind and RH trends for another
period of fog around 12Z but currently appears more cloud and
wind should occur than last night.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...Wolters
AVIATION...65
Area Forecast Discussion
National Weather Service Flagstaff AZ
241 AM MST TUE JUN 28 2016
.SYNOPSIS...Monsoon activity will be on the increase over the
next few days as a moist southerly flow develops across Arizona.
Look for showers and thunderstorms each day with the best
potential for heavy rain arriving on Thursday and Friday.
&&
.DISCUSSION...High pressure was centered over the four corners
region during the early morning hours leaving the door open for
the flow of moisture from the south and southeast. For
today...weather conditions will be very similar to those on
Monday. Not looking at much additional moisture so storms will
tend to be high based producing gusty winds in the 30-50 mph range
and brief/localized downpours. The main difference is that storm
activity in Arizona will extend further north to the Utah border.
For Wednesday through Friday...The high center gradually shifts
to a position over Texas with southerly flow developing across
Arizona. The southerly flow pattern will be favorable for deep
moisture over Northwest Mexico and the Gulf of California to move
northward. In addition, there will be a good chance for a
convective blow-up in Mexico (known as a mesoscale convective
complex) which could induce a Gulf of California surge pushing
additional moisture into the state. We`ll be keeping and eye on
Thursday and Friday because those two days show the best
potential for storms producing extremely rain.
From Saturday onward...The flow becomes more westerly with origins
from over the eastern Pacific Ocean. Under this regime look for a
bit of drying and stabilization with a downturn in thunderstorm
activity anticipated.
&&
.AVIATION...For the 12Z Package...Light SHRA persisting this morning
mainly west of a KPGA-KFLG line. Scattered TSRA will redevelop aft
18Z Tues. Local wind gusts up to 35 kts and moderate rain possible
with storms. Storm coverage to decrease by 03-06Z. Aviation
discussion not updated for TAF amendments.
&&
.FIRE WEATHER...An active monsoon pattern in place across northern
Arizona will produce daily rounds of scattered showers and
thunderstorms. Storm motion will be from southeast to northwest
today becoming very light on Wednesday. Expect erratic and gusty
winds near showers and storms.
Thursday through Saturday...The active Monsoon weather pattern will
continue with scattered showers and thunderstorms each day
and close to average temperatures across northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...McCollum
AVIATION...MCS
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Flagstaff AZ
241 AM MST TUE JUN 28 2016
.SYNOPSIS...Monsoon activity will be on the increase over the
next few days as a moist southerly flow develops across Arizona.
Look for showers and thunderstorms each day with the best
potential for heavy rain arriving on Thursday and Friday.
&&
.DISCUSSION...High pressure was centered over the four corners
region during the early morning hours leaving the door open for
the flow of moisture from the south and southeast. For
today...weather conditions will be very similar to those on
Monday. Not looking at much additional moisture so storms will
tend to be high based producing gusty winds in the 30-50 mph range
and brief/localized downpours. The main difference is that storm
activity in Arizona will extend further north to the Utah border.
For Wednesday through Friday...The high center gradually shifts
to a position over Texas with southerly flow developing across
Arizona. The southerly flow pattern will be favorable for deep
moisture over Northwest Mexico and the Gulf of California to move
northward. In addition, there will be a good chance for a
convective blow-up in Mexico (known as a mesoscale convective
complex) which could induce a Gulf of California surge pushing
additional moisture into the state. We`ll be keeping and eye on
Thursday and Friday because those two days show the best
potential for storms producing extremely rain.
From Saturday onward...The flow becomes more westerly with origins
from over the eastern Pacific Ocean. Under this regime look for a
bit of drying and stabilization with a downturn in thunderstorm
activity anticipated.
&&
.AVIATION...For the 12Z Package...Light SHRA persisting this morning
mainly west of a KPGA-KFLG line. Scattered TSRA will redevelop aft
18Z Tues. Local wind gusts up to 35 kts and moderate rain possible
with storms. Storm coverage to decrease by 03-06Z. Aviation
discussion not updated for TAF amendments.
&&
.FIRE WEATHER...An active monsoon pattern in place across northern
Arizona will produce daily rounds of scattered showers and
thunderstorms. Storm motion will be from southeast to northwest
today becoming very light on Wednesday. Expect erratic and gusty
winds near showers and storms.
Thursday through Saturday...The active Monsoon weather pattern will
continue with scattered showers and thunderstorms each day
and close to average temperatures across northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...McCollum
AVIATION...MCS
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Flagstaff AZ
919 PM MST MON JUN 27 2016
.SYNOPSIS...Daily showers and thunderstorms will increase across
northern Arizona this week as a deep moist southerly flow
develops across the state. Strong, gusty winds are possible near
any storms along with heavy rain and lightning.
&&
.DISCUSSION...
Only isolated and generally light showers are expected to continue
this evening and overnight across northern Arizona. Storms are
anticipated to redevelop by late Tuesday morning.
&&
.PREV DISCUSSION /340 PM MST/...Showers and thunderstorms
increased across our CWA this afternoon. The least activity is
over northwest Coconino County this afternoon. The center of high
pressure will migrate over far northwest New Mexico by Tuesday.
This will bring a deep and moist southeast to south flow over
Arizona. This will lead to increasing chances for showers and
thunderstorms each day across all of northern Arizona. Expect
better chances for measurable rainfall starting Wednesday. This
moisture is expected to remain in place through at least Saturday
bringing daily chances for showers and thunderstorms.
&&
.AVIATION...For the 06Z Package...A few showers may continue
overnight, though conditions will be generally improving.
Scattered showers and thunderstorms are expected to redevelop
after 18Z Tuesday. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...An active monsoon pattern in place across northern
Arizona will cause daily rounds of scattered showers and
thunderstorms. Storm motion will generally be from the south to
north. Expect erratic and gusty winds near showers and storms.
Thursday through Saturday...An active and wet Monsoon weather
pattern will continue with scattered showers and thunderstorms
each day across northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...KD/MAS
AVIATION...KD
FIRE WEATHER...RR
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Flagstaff AZ
919 PM MST MON JUN 27 2016
.SYNOPSIS...Daily showers and thunderstorms will increase across
northern Arizona this week as a deep moist southerly flow
develops across the state. Strong, gusty winds are possible near
any storms along with heavy rain and lightning.
&&
.DISCUSSION...
Only isolated and generally light showers are expected to continue
this evening and overnight across northern Arizona. Storms are
anticipated to redevelop by late Tuesday morning.
&&
.PREV DISCUSSION /340 PM MST/...Showers and thunderstorms
increased across our CWA this afternoon. The least activity is
over northwest Coconino County this afternoon. The center of 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 will 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 06Z Package...A few showers may continue
overnight, though conditions will be generally improving.
Scattered showers and thunderstorms are expected to redevelop
after 18Z Tuesday. 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.
&&
$$
PUBLIC...KD/MAS
AVIATION...KD
FIRE WEATHER...RR
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Flagstaff AZ
919 PM MST MON JUN 27 2016
.SYNOPSIS...Daily showers and thunderstorms will increase across
northern Arizona this week as a deep moist southerly flow
develops across the state. Strong, gusty winds are possible near
any storms along with heavy rain and lightning.
&&
.DISCUSSION...
Only isolated and generally light showers are expected to continue
this evening and overnight across northern Arizona. Storms are
anticipated to redevelop by late Tuesday morning.
&&
.PREV DISCUSSION /340 PM MST/...Showers and thunderstorms
increased across our CWA this afternoon. The least activity is
over northwest Coconino County this afternoon. The center of high
pressure will migrate over far northwest New Mexico by Tuesday.
This will bring a deep and moist southeast to south flow over
Arizona. This will lead to increasing chances for showers and
thunderstorms each day across all of northern Arizona. Expect
better chances for measurable rainfall starting Wednesday. This
moisture is expected to remain in place through at least Saturday
bringing daily chances for showers and thunderstorms.
&&
.AVIATION...For the 06Z Package...A few showers may continue
overnight, though conditions will be generally improving.
Scattered showers and thunderstorms are expected to redevelop
after 18Z Tuesday. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...An active monsoon pattern in place across northern
Arizona will cause daily rounds of scattered showers and
thunderstorms. Storm motion will generally be from the south to
north. Expect erratic and gusty winds near showers and storms.
Thursday through Saturday...An active and wet Monsoon weather
pattern will continue with scattered showers and thunderstorms
each day across northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...KD/MAS
AVIATION...KD
FIRE WEATHER...RR
For Northern Arizona weather information visit
weather.gov/flagstaff
[top]
Area Forecast Discussion
National Weather Service Tucson AZ
917 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...Water vapor imagery and 28/00Z upper-air plots show a
ridge that extends from southern Utah across the four corners into
western New Mexico and Chihuahua Mexico. Meanwhile, an inverted
trough is currently moving westward across southwestern Arizona,
southern California and northern Baja. This system is responsible
for the shower and thunderstorm activity that occurred earlier today
over north central portions of Arizona and currently affecting parts
of western Arizona, generally north of Interstate 8 to Interstate
40. Closer to home, only isolated weak showers are affecting the
northern fringes of my forecast area over parts of Pinal and
northeast Pima county near Oracle to Oro Valley.
IR satellite imagery shows some mid and upper level debris
cloudiness over central and eastern parts of the forecast area.
Farther south over southern Sonora Mexico is an MCS, which is still
in full swing with cloud tops at minus 71-73 degs C and this system
could result in boundaries pushing north or northwest toward my
forecast area overnight. That said, will keep a slight chance of
showers and thunderstorms in the forecast for mainly central and
eastern zones through the remainder of the overnight period, in case
additional activity pops up on approaching boundaries.
As of 04Z (9 PM MST), temperatures across the region ranged from the
mid 80s to the mid 90s. The Tucson Intl Airport reported a temp of
94 degs, after reaching an afternoon high temperature of 104 degs,
which was 2 degs above normal for this date. The current readings
seem to be on track with the inherited/expected overnight low temps
but will make some adjustments to the short term hourly temperature
grids to reflect these recent trends.
For details regarding the forecast beyond tonight, please see the
previous discussion below.
&&
.AVIATION...VALID THRU 28/12Z.
Slight chance of -TSRA/-SHRA through the night. Cloud decks
generally ranging from 10k-15k ft msl, and surface wind terrain
driven mainly less than 12 kts. Isold to Scattered TSRA/SHRA
developing again Tuesday afternoon and evening. Aviation discussion
not updated for TAF amendments.
&&
.FIRE WEATHER...Scattered showers and thunderstorms will prevail
into next weekend. 20-foot winds 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"
&&
.PREV DISCUSSION...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.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
[top]
Area Forecast Discussion
National Weather Service Phoenix AZ
730 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...
The most pronounced shortwave has progressed towards the southern CA
coast this evening, however strongly difluent jet level flow has
supported larger scale ascent through much of northern and central
AZ. 21Z KPSR sounding data sampled a well mixed sfc-650mb boundary
layer with moisture solidly at 8 g/kg. Meanwhile, 00Z KTWC sounding
was slightly better with 9 g/kg; and prevailing SE flow was
advecting this moisture profile towards steeper lapse rates and
better dynamics. While notable Cinh was evident in objective
analysis, outflow boundaries descending from higher elevations have
been sufficiently deep to invigorate new deep convection. This has
yielded gusts as high as 35mph and localized dense blowing dust.
Activity through western AZ may be meeting the end of its life cycle
shortly as a more abrupt instability gradient exists along the
Colorado River. Meanwhile, new activity forced along a boundary and
orographics through SE Pinal County may enhance deeper outflow and
enhance isolated development in higher terrain of NE Pinal County
while also creating a dust problem at lower elevations. Have
adjusted some pops for current radar trends and further adjustments
may be necessary going through the evening.
&&
.PREVIOUS DISCUSSION...
/156 PM MST MON JUN 27 2016/
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:
Lower confidence forecast as several competing outflow boundaries
will create frequent wind shifts through the evening, before
settling on a predominant easterly direction overnight. There is a
fairly low chance of blowing dust making it into the Phoenix
terminals and lesser chance of actual storms impacting the terminal
sites. Easterly sfc winds should prevail much longer into the late
afternoon Tuesday than is typical.
Southeast California/Southwest Arizona including KIPL and KBLH:
Wind shifts will be the main forecast challenge in SE CA through
tonight as outflow boundaries move into the region from AZ. Brief
gusts will be possible at KBLH, but likely minimal impact at KIPL.
Periods of variability in sfc winds will be likely overnight, then
favor a southerly component Tuesday afternoon. Periodic cloud decks
12K-15K ft will be common across the region.
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...MO/AJ/CB
AVIATION...MO
FIRE WEATHER...Deemer
Area Forecast Discussion
National Weather Service Phoenix AZ
730 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...
The most pronounced shortwave has progressed towards the southern CA
coast this evening, however strongly difluent jet level flow has
supported larger scale ascent through much of northern and central
AZ. 21Z KPSR sounding data sampled a well mixed sfc-650mb boundary
layer with moisture solidly at 8 g/kg. Meanwhile, 00Z KTWC sounding
was slightly better with 9 g/kg; and prevailing SE flow was
advecting this moisture profile towards steeper lapse rates and
better dynamics. While notable Cinh was evident in objective
analysis, outflow boundaries descending from higher elevations have
been sufficiently deep to invigorate new deep convection. This has
yielded gusts as high as 35mph and localized dense blowing dust.
Activity through western AZ may be meeting the end of its life cycle
shortly as a more abrupt instability gradient exists along the
Colorado River. Meanwhile, new activity forced along a boundary and
orographics through SE Pinal County may enhance deeper outflow and
enhance isolated development in higher terrain of NE Pinal County
while also creating a dust problem at lower elevations. Have
adjusted some pops for current radar trends and further adjustments
may be necessary going through the evening.
&&
.PREVIOUS DISCUSSION...
/156 PM MST MON JUN 27 2016/
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:
Lower confidence forecast as several competing outflow boundaries
will create frequent wind shifts through the evening, before
settling on a predominant easterly direction overnight. There is a
fairly low chance of blowing dust making it into the Phoenix
terminals and lesser chance of actual storms impacting the terminal
sites. Easterly sfc winds should prevail much longer into the late
afternoon Tuesday than is typical.
Southeast California/Southwest Arizona including KIPL and KBLH:
Wind shifts will be the main forecast challenge in SE CA through
tonight as outflow boundaries move into the region from AZ. Brief
gusts will be possible at KBLH, but likely minimal impact at KIPL.
Periods of variability in sfc winds will be likely overnight, then
favor a southerly component Tuesday afternoon. Periodic cloud decks
12K-15K ft will be common across the region.
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.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...MO/AJ/CB
AVIATION...MO
FIRE WEATHER...Deemer
Area Forecast Discussion
National Weather Service Flagstaff AZ
340 PM MST MON JUN 27 2016
.SYNOPSIS...Daily showers and thunderstorms will increase across
norther Arizona this week as a deep moist southerly flow developes
across the state. Strong, gusty winds are possible near any storms
along with heavy rain and lightning.
&&
.Discussion...Showers and thunderstorms increase across our CWA this
afternoon. The least activity is over northwest Coconino County
this afternoon.
The center of the high pressure will migrate over far northwest New
Mexico by Tuesday. This will bring a deep and moist southeast to
south flow over Arizona. This lead to increasing chances for showers
and thunderstorms each day across all of northern Arizona. Expect
better chances for measurable rainfall starting Wednesday. This
moisture is expected to remain in place through at least Saturday
bringing daily chances for showers and thunderstorms.
&&
.AVIATION...For the 00Z Package...Isolated to scattered TSRA are
expect to continue through 06Z Tue. Gusty winds near 40 kts and
moderate rain are possible in storms. A few showers may continue
overnight, with best chances for this in Coconino and Yavapai
Counties. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...An active monsoon pattern in place across northern
Arizona will cause daily rounds of scattered showers and
thunderstorms. Storm motion will generally be from the south to
north. Expect erratic and gusty winds near showers and storms.
Thursday through Saturday...An active and wet Monsoon weather
pattern will continue with scattered showers and thunderstorms each
day across northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.......MAS
AVIATION.....RR
FIRE WEATHER...RR
For Northern Arizona weather information visit
weather.gov/flagstaff
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
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
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 Topeka KS
500 AM CDT TUE JUN 28 2016
.SHORT TERM...(Today and Tonight)
Issued at 411 AM CDT TUE JUN 28 2016
A complex of thunderstorms continued to move southeast early this
morning, showing signs of intermittent severe downburst winds.
Overall parameters are not particularly favorable for severe storms,
but the organized cold pool has been able to interact with elevated
instability and modest deep layer wind shear to provide periods of
intensification and organization of rear inflow jets and downdraft
surges. It is these features that will continue to be monitored for
severe wind potential...and severe hail is a minimal secondary
hazard along with locally heavy rain. These storms have become
organized enough that they seem to be developing a convectively
enhanced MCV aloft, and would expect this feature to move southeast
with the storms and probably continue to enhance convection and
rainfall rates...and also steer the motion of the storms a bit.
Expect storms to gradually diminish and move out of the area by mid
to late morning. Beyond that time, should see mainly dry conditions
through the rest of the day. Additional storms will likely develop
in Nebraska and move south and southeast into the evening but there
is some uncertainty in whether they will have sufficient instability
to progress into northeast KS, and chances seem pretty low. A more
organized MCS is likely to develop farther west, and remain mainly
west of the forecast area through the evening although the eastern
fringes could stretch into north central KS. Then later on tonight,
additional forcing moves across eastern Nebraska...and again may be
able to support storms into central and eastern KS closer to sunrise
but instability should be weak and severe potential seems quite
low or nil from noon today at least through tonight.
.LONG TERM...(Wednesday through Monday)
Issued at 411 AM CDT TUE JUN 28 2016
Overall extended period remains unsettled with an active pattern of
weak embedded troughs traversing through the region, bringing
multiple chances for convection through Sunday. There are a few
periods where confidence in precip increases with a more optimal
forcing mechanism Thursday evening through Saturday evening.
Otherwise, confidence is fairly low in coverage of pops - highly
dependent on mesoscale factors that mid term models are unable to
discern this far out.
Convection on Wednesday afternoon and evening, mainly focuses over
north central areas. Timing of convection on Tuesday evening will
dictate this scenario as the NAM continues to be highlighting an MCS
over western KS during this time, while other guidance focuses the
activity further east towards central/north central areas during the
early afternoon Wednesday. Will need to monitor highs as guidance
may be trending too cool based on the coverage of precipitation and
cloud cover. I raised highs a few degrees for now as current
thinking sides with precip remaining mostly west of our area with
mostly sunny skies in the late afternoon and temps in the middle
80s.
Will likely see a break Wednesday evening before the cold front
arrives from the west Thursday afternoon, providing a better source
of lift for thunderstorms to develop. Lapse rates aloft remain weak
while ample instability and effective shear values peak at around 40
kts, lending to a few strong to severe storms, especially along and
south of the Interstate 70 corridor. Raised pops to likely south of
Interstate 70 for this period as all guidance points to the boundary
hanging up across southern KS with periods of thunderstorms
redeveloping in the afternoon hours on Friday. Mid level flow
becomes more westerly by this time, allowing for several vorticity
lobes to track from the southwest through Saturday evening.
Organized severe weather during this period is low, but cannot rule
out isolated storms being on the stronger side. On the north side of
the front, much of northeast Kansas remains on the cool side with
highs in the lower 80s and lows in the 60s. On Sunday and Monday,
while models are in large disagreement, there are trends in
shortwave ridging aloft bring a temporary end to precip chances for
the July fourth holiday. During the day, southerly flow returns
along with the heat and humidity as readings rise in to the lower
90s.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
Issued at 1153 PM CDT MON JUN 27 2016
Will continue with VFR forecast. Still appears enough wind and
cloud will keep BR/FG in check. Low probabilities of high-based
precip exist much of this forecast, too low for any inclusion.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barjenbruch
LONG TERM...Prieto
AVIATION...65
[top]
Area Forecast Discussion
National Weather Service Goodland KS
330 AM MDT TUE JUN 28 2016
.SHORT TERM...(Today through Thursday night)
Issued at 330 AM MDT Tue Jun 28 2016
Upper level high pressure centered over southern Utah early this
morning with low pressure moving south into the Great Lakes. The
upper high is forecast to gradually slide southeast into New Mexico
tomorrow then into west Texas Thursday.
Weather disturbances (per 700-500mb humidity) and associated
showers/thunderstorms are forecast to move in from the north-
northeast late this evening and continue overnight. Drier air aloft
moves in during the day Wednesday with little if any precipitation
expected. Depending on what model you believe we may see some
showers and thunderstorms Wednesday night before tapering off after
midnight. For Thursday through Thursday night precipitation chances
increase as a more significant system moves southeast across much of
the area. The models arent handling each weather disturbance very
well thus timing and precipitation amounts vary.
High temperatures today in the low 90s. Low temperatures in the
upper 50s to low 60s. For Wednesday afternoon am expecting high
temperatures to range from the mid 80s to around 90 along the KS/NE
border as well as Norton and Hill City areas with low to mid 90s
elsewhere. Low temperatures again in the upper 50s to low 60s. For
Thursday noticeably cooler with afternoon temperatures in the mid
70s to mid 80s. Low temperatures in the mid 50s to low 60s.
.LONG TERM...(Friday through Monday)
Issued at 214 AM MDT Tue Jun 28 2016
The upper level flow over the CONUS, for the most part, has been
consistent via the model runs over the past 3-4 days; with a ridge
in the west, trough in the east and a trough starting to push into
the Pacific Northwest. It was mentioned yesterday that by Friday the
500 mb flow was going to start shifting to a more west northwest
flow, and this has held true again in the newest model runs (the
European has a more zonal flow though compared to the GFS). This is
due to the trough in the eastern CONUS becoming less amplified and
moving more northeast and allowing the ridge to shift south. Due to
this shift and upper level flow having a more westerly component,
the model runs are now showing the higher chances for storms to be
to the south of the CWA on Friday and Saturday. Yet, this does not
mean the region will not get rain and storms, just the greatest
instability and lift are to the south. Sunday and Monday look to be
drier than the other days in the extended but Monday specifically
has less of a chance for precipitation than Sunday. This is due to
the ridge shifting again and engulfing the CWA. Overall, precip
chances are still possible every day but start to diminish in the
latter half of the extended. Temperatures will be in the 70s and 80s
Friday before they begin to increase back into the 90s on Monday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 330 AM MDT Tue Jun 28 2016
KGLD...vfr conditions expected through the period. Will have to
watch for an isolated storm around taf issuance as a cell is
moving through KIML heading toward KGLD. Otherwise should see
quite a bit of sunshine with winds becoming east-southeast then
southeast at 10kts or less. Thunderstorm probabilities increase
after about 00z and peak in the 03z-09z timeframe before
decreasing. Severe weather and heavy rainfall possible which could
produce mvfr cigs and/or visibilities. Winds remain from the
southeast around 10kts but could see some higher gusts around 00z.
KMCK...vfr conditions expected through the period. Similar to KGLD
should see quite a bit of sunshine with winds from the southeast
near 10kts. Thunderstorm probabilities increase after about 22z
and peak in the 02z-07z timeframe. Severe weather and heavy
rainfall possible which could produce mvfr cigs and/or
visibilities.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...99
LONG TERM...CLT
AVIATION...99
[top]
Area Forecast Discussion
National Weather Service Dodge City KS
326 AM CDT TUE JUN 28 2016
...Updated Short Term and Long Term Sections...
.SHORT TERM...(Today and tonight)
Issued at 325 AM CDT Tue Jun 28 2016
The northwest flow pattern is underway, and along with it a
challenging forecast. At the time of this writing at 0800 UTC, there
were two small MCSs, one across far eastern Colorado and adjacent
far western KS with a second one across far north central KS. It
looks like a majority of the southwest KS region will avoid both of
these MCSs as they track almost due south. The exception will be the
western six counties were some rainfall of around a quarter inch can
be expected with some locally higher amounts through the mid-morning
hours before the MCS weakens. Some of the hourly HRRR runs want to
merge the two MCSs, so that will have to be watched later in the
morning, but right now that doesn`t seem to be happening, so we will
be keeping POPs fairly low with the exception of far southwest and
west central KS.
It is unclear exactly how convection will evolve late this afternoon
through tonight. We could see a repeat of yesterday, except starting
off a bit farther north in Nebraska. A mature MCS never really
materialized last night like was forecast, however that does not
mean that one large, cohernet, long-lived MCS won`t happen tonight.
Signals are certainly there in both the high resolution convective
allowing models and lower resolution models. The NAM12 is
particularly bullish, showing a significant QPF signal rolling SSE
from western Nebraska into southwest KS by 12z Wednesday. Both the
NCEP WRF-ARW and WRF-NMMB show something coherent rolling across the
same generally area before decaying around or shortly after 09z
Wednesday. In the official forecast, we will have 40-50 POPs going
mainly east and north of a Dighton-Dodge-Greensburg-Pratt line with
greatest confidence and QPF forecast values up along the I-70
corridor.
.LONG TERM...(Wednesday through Monday)
Issued at 325 AM CDT Tue Jun 28 2016
The active northwest flow pattern will continue through the end of
the week. A couple of things that will probably act to enhance
precipitation coverage and intensity later in the week will be 1) a
fairly decent surface front which will slow down and perhaps become
quasi-stationary across southern Kansas and 2) some minor mid level
perturbations/enhanced mid level moisture rotating around weak
ridging, thanks to abundance of mountain convection across the
southern Rockies. POPs in the Long Term will be highest Thursday
Night through Saturday Night with 12-hr POPs every period in the 40-
60 percent territory somewhere across our forecast area from west
central KS through south central KS. It still looks as though some
areas will see potentially excessive rainfall once the polar front
gets down here, given all the moisture that will be around and the
generally weak mid-upper level flow leading to slow-moving
convection.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1216 AM CDT Tue Jun 28 2016
Will be playing the TAFs fairly conservatively given the fact that
it is difficult to latch on to any coherent convective signal for
much of the forecast period. That said, the near term HRRR
solution does suggest a small thunderstorm cluster moving south
from the Goodland area, clipping the GCK area overnight, so we
will include a 3 hour period of VCTS at that terminal, but
elsewhere (DDC and HYS) we will keep the TAFs free of convection
until there is something concrete to latch onto. A rather large
MCS may drive south late tomorrow evening affecting much of
western Kansas, but since this is at the very end of this forecast
cycle, we will not introduce the threat into the TAF yet.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 88 67 90 66 / 20 40 20 30
GCK 89 66 91 66 / 20 30 20 20
EHA 90 67 94 66 / 40 20 20 30
LBL 91 67 94 67 / 30 20 20 30
HYS 87 66 86 65 / 20 50 40 40
P28 90 68 90 69 / 10 30 30 40
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Umscheid
AVIATION...Umscheid
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1154 PM CDT MON JUN 27 2016
...Update to aviation forecast discussion...
.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 06Z TAFS through 06Z Tuesday Night)
Issued at 1153 PM CDT MON JUN 27 2016
Will continue with VFR forecast. Still appears enough wind and
cloud will keep BR/FG in check. Low probabilities of high-based
precip exist much of this forecast, too low for any inclusion.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...Wolters
AVIATION...65
Area Forecast Discussion
National Weather Service Phoenix AZ
820 AM MST TUE JUN 28 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...
The complicated upper level flow pattern of the past few days
continued this morning. First. The western and northern leading edge
monsoon moisture boundary (MMB) moved west yesterday. This morning
the MMB was up against the CA coastal mountains in southeast CA,
then northeast to Needles CA, then east to just south of Flagstaff.
Monsoon moisture was not excessive by any means, but on the moisture
scale it was minimally monsoonish, but slightly deeper in southeast
AZ. Compare the Phoenix and Tucson soundings for yourself and see
the difference. Additionally, afternoon convective trigger
temperatures at south central and southeast AZ above 3200 feet msl
were 5 to 7 degrees lower than forecast values, a good sign for
thermodynamic instability.
Again, mid and upper level flows, replete with perturbations
continued. Morning water vapor satellite imagery showed the slow
moving inverted trof that came out of Sonora Mexico yesterday will
slowly grind through northwest and north central AZ, a focus of
additional storms today especially along the MMB. And in southeast
AZ, a weak 300/250 mb disturbance will move out of the central Gulf
of CA toward the Mexican border south of Tucson today. At the same
time, a weak 500 mb inverted trof comes from a different direction,
from southern New Mexico westward into parts of southeast AZ.
However the 500 mb plot chart showed an odd ball very warm minus 3
degree C temp at El Paso which would imply a more stable airmass.
Scrutiny of the El Paso sounding showed it was an aberration, an
isolated temperature spike, so realistically the mid level airmass
should look the same as the surrounding upper air stations. On
another note. Models forecast another 300/250 mb disturbance, from
just off the Baja coast, to move into far southeast AZ on Wednesday
for more afternoon and evening convective storms.
So what does all the above mean? There should be more instability
in the mountains north, east and south of Phoenix by late this
afternoon. Easterly mid level convective steering currents should
move mountain convection west toward the central deserts, with
possible convective outflows and or merging outflows from the north
and east. This has the potential to spark late afternoon/evening
convection on the south central AZ deserts, including the Phoenix
area. Some with blowing dust.
On another note. Regional analysis showed a much drier airmass over
northeast AZ and northern New Mexico that was thought to move into
AZ later in the extended period. However in our estimation today,
low level south and southeast flows for the next 7 days will
continue to advect and supply the southern half of AZ with
additional monsoon moisture. See this mornings precipitable water
imagery. The moisture rich source regions are El Paso, Chihuahua
Mexico, and the excessively moist Gulf of CA.
Current forecasts for higher than normal precip probabilities on the
south central AZ deserts and mountains, including Phoenix for later
this afternoon and evening look good for now. No updates planned.
.PREVIOUS DISCUSSION...535 AM MST...
Numerous circulations and a few outflows are present on this AM`s
IR/WV imagery, fairly typical this time of year between inverted wave
advection, remnant convective meso-lows and gravity waves. Lingering
light shower activity has exited the forecast area to the northwest,
heading into Mohave and Yavapai Counties this early AM. Widely
isolated showers are still drifting westward on Tucson`s radar near
a localized meso-low and along the northwestern flank and deformation
zone of a larger inverted wave over Chihuahua and Sonora sampled
best at the 500mb level. Vertically speaking, the anticyclonic
circulation placement throughout the significant levels (i.e. 700mb,
500mb, 300mb) is really all over the map, with the 700mb circ east of
the Rockies, 500mb over the Great Basin and the UL centers well to
our south over Mexico.
The upper difluence observed last evening over N AZ doesn`t appear
to be as great tonight however advection of favorable ML lapse rates
down along portions of the Rim are part of today`s set-up. Several
Hi-Res models develop storms over the Rim again today with several
solns pointing to a more organized outflow intrusion from the
northeast around or post 29/00z (5 pm local) into Phoenix. While
always a concern during the Monsoon, northeasterly outflows into
Phoenix aren`t typical dust producers. What could lead to blowing
dust later into the evening would be the propagation of storm
activity along intersecting outflows surviving into the lower desert
elevations. PoP chances go as far west as the Colorado River Valley
and Southwest AZ Deserts, with drier conditions in terms of PoPs but
not much by way of humidities for the western forecast zones. Broader
anticyclonic flow and a drier atmospheric column will support much
warmer-than-normal temperatures for portions of southeast CA,
especially for the Imperial Valley today and Wednesday. Conditions
look to just escape Excessive Heat Warning criteria today, but may
develop for Wednesday. It`s tricky this time of year to gauge if
long-traveling outflows or MCVs could import moisture or cloud cover
to limit the diurnal curve, so will hold off as upstream moisture and
convective activity today over AZ could work in SE CA`s favor for
temperatures Wednesday.
Increasing Monsoon moisture levels and persistent inverted wave
breaking through the 700-500mb level will introduce deeper moisture
and additional dynamics to promote better chances for showers and
storms over the lower AZ deserts each day through the end of the work
week. Peak of the moisture and wave activity looks to be Thursday
into Friday, with significant enough cloud cover and potential for
rain-cooled air to cool forecast highs Friday across the south-
central AZ deserts into the upper 90s to low 100s. Gridded sky cover
guidance and several moisture fields (mixing ratio, humidities,
dewpoints) indicate a tight gradient lying in the vicinity of the CO
River Valley. While debris clouds are possible, increasing
southwesterly flow may prevent significant cloud cover development
west of the River and keep temperatures near normals through the end
of the week.
Beginning Saturday, low pressure will take shape over the Pac NW,
shifting the 500mb circulation further to our east/southeast and
allowing for stronger southwesterly steering flow to transition
through the area. Dry air advection from the Pacific results,
relegating the slight chances for the precip to the eastern AZ
mountains and out of the lower desert elevations. Under clearing
skies temperatures will see a warm-up, compared to those observed at
the end of the work week, and return to normal and seasonable values
by the Fourth of the July holiday.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL: For the
morning into the afternoon, expect winds to favor the southeast at
the terminals, mostly below 12kt with a slight tendency to then turn
towards the west. Variable mid/high level cloud decks will move
across the greater Phoenix area with most bases aoa 12k feet and
most broken decks aoa 15k feet. May see a few light showers or virga
from these decks this morning. Once again expect mountain
thunderstorms to develop east of Phoenix later this afternoon and
evening, a few of which may move into the central deserts and affect
the terminals after 03z or so. Will not get overly aggressive in the
TAFs this early and will stick with VCTS for now. Have added in
earlier than usual switch to east/southeast winds at the TAF sites,
mostly after 04z based on expected outflow winds moving into the
lower deserts.
Southeast California/Southwest Arizona including KIPL and KBLH: Most
convective weather to stay east of the area today and into the
evening hours with skies to be mostly sunny. Most cloud decks to be
few to sct with bases above 12k feet. Winds will be rather light
next 24 hours and occasionally variable but favoring the southeast
to south, likely turning back towards the west this evening at KIPL.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Thursday through Monday... Temperatures will continue to cool as
moisture increases, with south central Arizona lowering below 105
degrees and even below 100 after Thursday and into the weekend.
Modest warming expected later in the period as air mass dries a bit.
Monsoon moisture levels continue to increase over the region with
chances for afternoon thunderstorms expected across south central
Arizona through Friday and slight chances further west towards the
lower Colorado River valley. Over the weekend and into early next
week a drying trend from the west is expected and by Sunday isolated
thunderstorms should be mostly confined to higher terrain areas to
the east of Phoenix. Any storms that develop have the ability to
produce lightning, gusty winds, and wetting rains, especially
storms that develop across south central Arizona through Friday.
Minimum humidities through Friday will be highly elevated,
especially west of the lower Colorado River valley, with readings
generally 20 to 30 percent, and even higher across southern Gila
County. Readings will fall between 15 and 20 percent Saturday, then
down mostly below 15 percent Sunday into Monday as drier air spreads
over the area from the southwest. Winds each day will be on the
light side for the most part, mostly below 15 mph, but will be
locally breezy at times from the south west of Maricopa county and
along the lower Colorado River valley mainly during the afternoon
hours each day.
&&
.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/Nolte
AVIATION...CB
FIRE WEATHER...Deemer/CB
Area Forecast Discussion...Updated
National Weather Service Phoenix AZ
535 AM MST TUE JUN 28 2016
.UPDATE...Updated 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...
Numerous circulations and a few outflows are present on this AM`s
IR/WV imagery, fairly typical this time of year between inverted wave
advection, remnant convective meso-lows and gravity waves. Lingering
light shower activity has exited the forecast area to the northwest,
heading into Mohave and Yavapai Counties this early AM. Widely
isolated showers are still drifting westward on Tucson`s radar near
a localized meso-low and along the northwestern flank and deformation
zone of a larger inverted wave over Chihuahua and Sonora sampled
best at the 500mb level. Vertically speaking, the anticyclonic
circulation placement throughout the significant levels (i.e. 700mb,
500mb, 300mb) is really all over the map, with the 700mb circ east of
the Rockies, 500mb over the Great Basin and the UL centers well to
our south over Mexico.
The upper difluence observed last evening over N AZ doesn`t appear
to be as great tonight however advection of favorable ML lapse rates
down along portions of the Rim are part of today`s set-up. Several
Hi-Res models develop storms over the Rim again today with several
solns pointing to a more organized outflow intrusion from the
northeast around or post 29/00z (5 pm local) into Phoenix. While
always a concern during the Monsoon, northeasterly outflows into
Phoenix aren`t typical dust producers. What could lead to blowing
dust later into the evening would be the propagation of storm
activity along intersecting outflows surviving into the lower desert
elevations. PoP chances go as far west as the Colorado River Valley
and Southwest AZ Deserts, with drier conditions in terms of PoPs but
not much by way of humidities for the western forecast zones. Broader
anticyclonic flow and a drier atmospheric column will support much
warmer-than-normal temperatures for portions of southeast CA,
especially for the Imperial Valley today and Wednesday. Conditions
look to just escape Excessive Heat Warning criteria today, but may
develop for Wednesday. It`s tricky this time of year to gauge if
long-traveling outflows or MCVs could import moisture or cloud cover
to limit the diurnal curve, so will hold off as upstream moisture and
convective activity today over AZ could work in SE CA`s favor for
temperatures Wednesday.
Increasing Monsoon moisture levels and persistent inverted wave
breaking through the 700-500mb level will introduce deeper moisture
and additional dynamics to promote better chances for showers and
storms over the lower AZ deserts each day through the end of the work
week. Peak of the moisture and wave activity looks to be Thursday
into Friday, with significant enough cloud cover and potential for
rain-cooled air to cool forecast highs Friday across the south-
central AZ deserts into the upper 90s to low 100s. Gridded sky cover
guidance and several moisture fields (mixing ratio, humidities,
dewpoints) indicate a tight gradient lying in the vicinity of the CO
River Valley. While debris clouds are possible, increasing
southwesterly flow may prevent significant cloud cover development
west of the River and keep temperatures near normals through the end
of the week.
Beginning Saturday, low pressure will take shape over the Pac NW,
shifting the 500mb circulation further to our east/southeast and
allowing for stronger southwesterly steering flow to transition
through the area. Dry air advection from the Pacific results,
relegating the slight chances for the precip to the eastern AZ
mountains and out of the lower desert elevations. Under clearing
skies temperatures will see a warm-up, compared to those observed at
the end of the work week, and return to normal and seasonable values
by the Fourth of the July holiday.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL: For the
morning into the afternoon, expect winds to favor the southeast at
the terminals, mostly below 12kt with a slight tendency to then turn
towards the west. Variable mid/high level cloud decks will move
across the greater Phoenix area with most bases aoa 12k feet and
most broken decks aoa 15k feet. May see a few light showers or virga
from these decks this morning. Once again expect mountain
thunderstorms to develop east of Phoenix later this afternoon and
evening, a few of which may move into the central deserts and affect
the terminals after 03z or so. Will not get overly aggressive in the
TAFs this early and will stick with VCTS for now. Have added in
earlier than usual switch to east/southeast winds at the TAF sites,
mostly after 04z based on expected outflow winds moving into the
lower deserts.
Southeast California/Southwest Arizona including KIPL and KBLH: Most
convective weather to stay east of the area today and into the
evening hours with skies to be mostly sunny. Most cloud decks to be
few to sct with bases above 12k feet. Winds will be rather light
next 24 hours and occasionally variable but favoring the southeast
to south, likely turning back towards the west this evening at KIPL.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Thursday through Monday... Temperatures will continue to cool as
moisture increases, with south central Arizona lowering below 105
degrees and even below 100 after Thursday and into the weekend.
Modest warming expected later in the period as air mass dries a bit.
Monsoon moisture levels continue to increase over the region with
chances for afternoon thunderstorms expected across south central
Arizona through Friday and slight chances further west towards the
lower Colorado River valley. Over the weekend and into early next
week a drying trend from the west is expected and by Sunday isolated
thunderstorms should be mostly confined to higher terrain areas to
the east of Phoenix. Any storms that develop have the ability to
produce lightning, gusty winds, and wetting rains, especially
storms that develop across south central Arizona through Friday.
Minimum humidities through Friday will be highly elevated,
especially west of the lower Colorado River valley, with readings
generally 20 to 30 percent, and even higher across southern Gila
County. Readings will fall between 15 and 20 percent Saturday, then
down mostly below 15 percent Sunday into Monday as drier air spreads
over the area from the southwest. Winds each day will be on the
light side for the most part, mostly below 15 mph, but will be
locally breezy at times from the south west of Maricopa county and
along the lower Colorado River valley mainly during the afternoon
hours each day.
&&
.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...Nolte
AVIATION...CB
FIRE WEATHER...Deemer/CB
Area Forecast Discussion...Updated
National Weather Service Phoenix AZ
535 AM MST TUE JUN 28 2016
.UPDATE...Updated 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...
Numerous circulations and a few outflows are present on this AM`s
IR/WV imagery, fairly typical this time of year between inverted wave
advection, remnant convective meso-lows and gravity waves. Lingering
light shower activity has exited the forecast area to the northwest,
heading into Mohave and Yavapai Counties this early AM. Widely
isolated showers are still drifting westward on Tucson`s radar near
a localized meso-low and along the northwestern flank and deformation
zone of a larger inverted wave over Chihuahua and Sonora sampled
best at the 500mb level. Vertically speaking, the anticyclonic
circulation placement throughout the significant levels (i.e. 700mb,
500mb, 300mb) is really all over the map, with the 700mb circ east of
the Rockies, 500mb over the Great Basin and the UL centers well to
our south over Mexico.
The upper difluence observed last evening over N AZ doesn`t appear
to be as great tonight however advection of favorable ML lapse rates
down along portions of the Rim are part of today`s set-up. Several
Hi-Res models develop storms over the Rim again today with several
solns pointing to a more organized outflow intrusion from the
northeast around or post 29/00z (5 pm local) into Phoenix. While
always a concern during the Monsoon, northeasterly outflows into
Phoenix aren`t typical dust producers. What could lead to blowing
dust later into the evening would be the propagation of storm
activity along intersecting outflows surviving into the lower desert
elevations. PoP chances go as far west as the Colorado River Valley
and Southwest AZ Deserts, with drier conditions in terms of PoPs but
not much by way of humidities for the western forecast zones. Broader
anticyclonic flow and a drier atmospheric column will support much
warmer-than-normal temperatures for portions of southeast CA,
especially for the Imperial Valley today and Wednesday. Conditions
look to just escape Excessive Heat Warning criteria today, but may
develop for Wednesday. It`s tricky this time of year to gauge if
long-traveling outflows or MCVs could import moisture or cloud cover
to limit the diurnal curve, so will hold off as upstream moisture and
convective activity today over AZ could work in SE CA`s favor for
temperatures Wednesday.
Increasing Monsoon moisture levels and persistent inverted wave
breaking through the 700-500mb level will introduce deeper moisture
and additional dynamics to promote better chances for showers and
storms over the lower AZ deserts each day through the end of the work
week. Peak of the moisture and wave activity looks to be Thursday
into Friday, with significant enough cloud cover and potential for
rain-cooled air to cool forecast highs Friday across the south-
central AZ deserts into the upper 90s to low 100s. Gridded sky cover
guidance and several moisture fields (mixing ratio, humidities,
dewpoints) indicate a tight gradient lying in the vicinity of the CO
River Valley. While debris clouds are possible, increasing
southwesterly flow may prevent significant cloud cover development
west of the River and keep temperatures near normals through the end
of the week.
Beginning Saturday, low pressure will take shape over the Pac NW,
shifting the 500mb circulation further to our east/southeast and
allowing for stronger southwesterly steering flow to transition
through the area. Dry air advection from the Pacific results,
relegating the slight chances for the precip to the eastern AZ
mountains and out of the lower desert elevations. Under clearing
skies temperatures will see a warm-up, compared to those observed at
the end of the work week, and return to normal and seasonable values
by the Fourth of the July holiday.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL: For the
morning into the afternoon, expect winds to favor the southeast at
the terminals, mostly below 12kt with a slight tendency to then turn
towards the west. Variable mid/high level cloud decks will move
across the greater Phoenix area with most bases aoa 12k feet and
most broken decks aoa 15k feet. May see a few light showers or virga
from these decks this morning. Once again expect mountain
thunderstorms to develop east of Phoenix later this afternoon and
evening, a few of which may move into the central deserts and affect
the terminals after 03z or so. Will not get overly aggressive in the
TAFs this early and will stick with VCTS for now. Have added in
earlier than usual switch to east/southeast winds at the TAF sites,
mostly after 04z based on expected outflow winds moving into the
lower deserts.
Southeast California/Southwest Arizona including KIPL and KBLH: Most
convective weather to stay east of the area today and into the
evening hours with skies to be mostly sunny. Most cloud decks to be
few to sct with bases above 12k feet. Winds will be rather light
next 24 hours and occasionally variable but favoring the southeast
to south, likely turning back towards the west this evening at KIPL.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Thursday through Monday... Temperatures will continue to cool as
moisture increases, with south central Arizona lowering below 105
degrees and even below 100 after Thursday and into the weekend.
Modest warming expected later in the period as air mass dries a bit.
Monsoon moisture levels continue to increase over the region with
chances for afternoon thunderstorms expected across south central
Arizona through Friday and slight chances further west towards the
lower Colorado River valley. Over the weekend and into early next
week a drying trend from the west is expected and by Sunday isolated
thunderstorms should be mostly confined to higher terrain areas to
the east of Phoenix. Any storms that develop have the ability to
produce lightning, gusty winds, and wetting rains, especially
storms that develop across south central Arizona through Friday.
Minimum humidities through Friday will be highly elevated,
especially west of the lower Colorado River valley, with readings
generally 20 to 30 percent, and even higher across southern Gila
County. Readings will fall between 15 and 20 percent Saturday, then
down mostly below 15 percent Sunday into Monday as drier air spreads
over the area from the southwest. Winds each day will be on the
light side for the most part, mostly below 15 mph, but will be
locally breezy at times from the south west of Maricopa county and
along the lower Colorado River valley mainly during the afternoon
hours each day.
&&
.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...Nolte
AVIATION...CB
FIRE WEATHER...Deemer/CB
[top]
Area Forecast Discussion
National Weather Service Tucson AZ
355 AM MST TUE JUN 28 2016
.SYNOPSIS...Scattered showers and thunderstorms will occur through
tonight, with the favored areas south of Tucson and across the White
Mountains. Increasing moisture and a favorable flow regime will then
provide even greater coverage of showers and thunderstorms Wednesday
through Friday. A drying trend will then limit thunderstorms to
mainly near the New Mexico border by early next week.
&&
.DISCUSSION...Isolated showers were occurring at this time across
eastern Santa Cruz County and southwestern Cochise County southeast
of Tucson. The showers that produced a few hundredths of an inch a
few hours ago across portions of the Tucson metro area have mostly
dissipated over the northern part of the Tohono O`Odham Nation.
Several HRRR solutions as well as the 28/00Z Univ. of AZ WRF-NAM and
WRF-GFS suggest that the ongoing showers will continue moving
westward during the next several hours, but are progged to end by
around 8 a.m. MST or so. Scattered showers and thunderstorms are
expected to return this afternoon and evening. The favored locales
for these showers and thunderstorms are southwest-to-southeast of
Tucson, and across the White Mountains. PoPs have been adjusted to
reflect this expectation. Enough moisture will exist for at least
isolated coverage of showers/tstms late tonight.
28/00Z GFS/ECMWF/CMC remain in very good agreement in depicting an
upswing in showers and thunderstorms starting Wednesday, and
particularly Thursday into Friday. High pressure aloft presently
centered near the Four Corners region will remain quasi-stationary
through Wednesday, then the upper high is progged to shift sewd and
become centered over central Texas around daybreak Friday. A fairly
deep easterly flow regime over this forecast Wednesday should become
increasingly sely Thursday, then more sly Friday. Am anticipating
ample moisture from the Gulf of California (a.k.a. Gulf of
California surge) to advect into southern Arizona by early Thursday.
Have noted that the deterministic GFS depicted precip water values
mainly around 1.30 - 1.40 inches or so today, increasing to 1.40 -
1.60 inches or so Wednesday, then 1.40 - 1.80 inches by Thursday.
The largest values are progged to be across western sections.
At any rate, the combination of ample moisture and a favorable flow
regime should provide scattered to numerous showers and
thunderstorms, especially during the afternoon/evening hours.
Somewhat less coverage of showers/tstms is forecast to occur in the
late night/early morning periods. Deep moisture over the area Friday
will be shunted eastward into New Mexico Saturday as generally wly
flow becomes established over the area. The ECMWF continued with a
generally wly flow aloft regime Sun-Mon, but the GFS the mid-level
flow to become ely by next Mon. At any rate, for this forecast
package have continued with the notion of a drying trend and
corresponding decrease in shower/tstm coverage Sun-Mon. Thus,
isolated to perhaps scattered coverage of showers/tstms Sunday, then
a slight chance of showers/tstms limited to mainly near the
mountains east and south of Tucson Monday.
Expect markedly lower daytime temps by Friday followed by a warming
Sat-Mon.
&&
.AVIATION...VALID THRU 29/12Z.
Scattered to broken clouds in multiple layers expected ranging from
10k-15k ft msl with isold -SHRA/-TSRA this morning and scattered
TSRA/SHRA this afternoon and evening. Diurnal surface winds of 12
kts or less expected through the period outside of thunderstorms.
Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...With plenty of moisture and instability we
will have daily rounds of scattered showers and thunderstorms
through Friday. The strongest storms will be capable of very strong
winds and heavy downpours especially during the mid afternoon to
early evening hours. The moisture will diminish across the region
Saturday onward resulting in a decrease in the amount of convection
each day. By Monday any isolated convection will be limited to the
mountains near the eastern border and over the White Mountains.
Cerniglia
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
DISCUSSION...Francis
AVIATION/FIRE WEATHER...Cerniglia
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
647 AM CDT TUE JUN 28 2016
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 411 AM CDT TUE JUN 28 2016
A complex of thunderstorms continued to move southeast early this
morning, showing signs of intermittent severe downburst winds.
Overall parameters are not particularly favorable for severe storms,
but the organized cold pool has been able to interact with elevated
instability and modest deep layer wind shear to provide periods of
intensification and organization of rear inflow jets and downdraft
surges. It is these features that will continue to be monitored for
severe wind potential...and severe hail is a minimal secondary
hazard along with locally heavy rain. These storms have become
organized enough that they seem to be developing a convectively
enhanced MCV aloft, and would expect this feature to move southeast
with the storms and probably continue to enhance convection and
rainfall rates...and also steer the motion of the storms a bit.
Expect storms to gradually diminish and move out of the area by mid
to late morning. Beyond that time, should see mainly dry conditions
through the rest of the day. Additional storms will likely develop
in Nebraska and move south and southeast into the evening but there
is some uncertainty in whether they will have sufficient instability
to progress into northeast KS, and chances seem pretty low. A more
organized MCS is likely to develop farther west, and remain mainly
west of the forecast area through the evening although the eastern
fringes could stretch into north central KS. Then later on tonight,
additional forcing moves across eastern Nebraska...and again may be
able to support storms into central and eastern KS closer to sunrise
but instability should be weak and severe potential seems quite
low or nil from noon today at least through tonight.
.LONG TERM...(Wednesday through Monday)
Issued at 411 AM CDT TUE JUN 28 2016
Overall extended period remains unsettled with an active pattern of
weak embedded troughs traversing through the region, bringing
multiple chances for convection through Sunday. There are a few
periods where confidence in precip increases with a more optimal
forcing mechanism Thursday evening through Saturday evening.
Otherwise, confidence is fairly low in coverage of pops - highly
dependent on mesoscale factors that mid term models are unable to
discern this far out.
Convection on Wednesday afternoon and evening, mainly focuses over
north central areas. Timing of convection on Tuesday evening will
dictate this scenario as the NAM continues to be highlighting an MCS
over western KS during this time, while other guidance focuses the
activity further east towards central/north central areas during the
early afternoon Wednesday. Will need to monitor highs as guidance
may be trending too cool based on the coverage of precipitation and
cloud cover. I raised highs a few degrees for now as current
thinking sides with precip remaining mostly west of our area with
mostly sunny skies in the late afternoon and temps in the middle
80s.
Will likely see a break Wednesday evening before the cold front
arrives from the west Thursday afternoon, providing a better source
of lift for thunderstorms to develop. Lapse rates aloft remain weak
while ample instability and effective shear values peak at around 40
kts, lending to a few strong to severe storms, especially along and
south of the Interstate 70 corridor. Raised pops to likely south of
Interstate 70 for this period as all guidance points to the boundary
hanging up across southern KS with periods of thunderstorms
redeveloping in the afternoon hours on Friday. Mid level flow
becomes more westerly by this time, allowing for several vorticity
lobes to track from the southwest through Saturday evening.
Organized severe weather during this period is low, but cannot rule
out isolated storms being on the stronger side. On the north side of
the front, much of northeast Kansas remains on the cool side with
highs in the lower 80s and lows in the 60s. On Sunday and Monday,
while models are in large disagreement, there are trends in
shortwave ridging aloft bring a temporary end to precip chances for
the July fourth holiday. During the day, southerly flow returns
along with the heat and humidity as readings rise in to the lower
90s.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday Morning)
Issued at 645 AM CDT TUE JUN 28 2016
Area of rain and thunderstorms will impact TAF sites through
around 14Z before coming to an end. Will have periods of reduced
vis and increased wind speeds with these storms. Thunderstorms
will probably be done after 14Z through the remainder of the TAF
period, but with lower end confidence.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barjenbruch
LONG TERM...Prieto
AVIATION...Barjenbruch
[top]
Area Forecast Discussion
National Weather Service Wichita KS
625 AM CDT TUE JUN 28 2016
.SYNOPSIS...
Issued at 228 AM CDT Tue Jun 28 2016
In the upper levels, ridging is centered over the four corners
region with a shortwave diving southeast over the western Great
Lakes. At the surface, high pressure is situated over ND/northern
MN with a loose cold front stretching across northern MO into
northern KS.
&&
.SHORT TERM...(Today through Friday night)
Issued at 228 AM CDT Tue Jun 28 2016
Just like last night, have low confidence in what is forcing
convection over northern KS as elevated parcels remain uncapped.
Best guess is that a weak upper impulse, convectively induced or
not, is what sparked off storms over far northern KS/southern
Nebraska. Will continue to monitor trends too see if this small
complex holds together, as we may need to increase pops over
central KS this morning.
Outside of this morning activity, should see a setup fairly
similar to what played out Mon, with the high Plains of
KS/Nebraska seeing the bulk of the daytime convection. These
storms should track southeast overnight and possibly a bit further
east compared to Mon evenings storms due to the better moisture
transport being pushed slightly east. Will keep with the overall
theme of keeping the highest storm chances along and especially
west of I-135. Feel that best the chance for storms Wed looks to
be Wed morning as the overnight storms continue to push southeast.
Northwest flow will remain over the Plains for Wed through Thu
night. There is a good signal that another round of elevated
convection will develop Wed night in an area of strong isentropic
lift in the 310-315k layer. 700mb temps also show a fairly tight
gradient through the forecast area with some warm advection over
this baroclinic zone.
For Thu into Thu night, there is good model agreement in a cold
front sliding down into the central Plains with this feature
stretching from northern MO into SW KS by 00z Fri. At the same
time, models also agree on some upper energy lifting out of the
desert sw and across the area for Fri into Fri night. The
combination of the front and a series of weak impulses will keep
decent storm chances in for Thu night through Fri night with
the southern half of KS looking to have the better chances.
Temps will finally start to cool to closer to or just below
seasonal normals. Most of the area should see 80s for highs for
Thu with much cooler air moving down across the region for Fri.
.LONG TERM...(Saturday through Monday)
Issued at 228 AM CDT Tue Jun 28 2016
Will keep fairly high storm chances in for Sat as the zonal
pattern remains active with models showing additional pieces of
energy lifting out of the four corners region. In addition, the
weak surface boundary looks to remain over the area through Sun
morning. There looks to be some agreement in the medium range
models in some weak upper ridging over the central/southern
Plains for Sun night into Mon, which should push the better precip
chances east.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 618 AM CDT Tue Jun 28 2016
Main aviation concern will be storms this morning and again later
tonight.
Storms developed over extreme north central KS a few hours ago.
Tough to find the forcing for these storms but best guess is that
this activity is developing ahead of a weak upper impulse diving
southeast in the NW flow. Current thinking is that this activity
will continue for at least the next few hours. Will include
either a tempo group or vcts at all sites this morning with the
exception of KICT. Late afternoon storms are expected to develop
once again over western Nebraska with this activity diving
southeast overnight. Areas generally west of I-135 will have the
best chance to see overnight storms, so will run with VCTS after
03z at KRSl-KGBD-KSLN.
There has been some periodic fog at KCNU early this morning but
with sun coming up and storms approaching, not expecting this to
last much longer.
Lawson
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 90 68 86 69 / 20 20 20 40
Hutchinson 88 67 87 67 / 20 30 30 40
Newton 89 67 86 67 / 30 20 20 40
ElDorado 89 68 86 67 / 30 20 20 40
Winfield-KWLD 90 69 88 69 / 20 10 20 30
Russell 89 66 85 65 / 40 50 50 50
Great Bend 89 66 86 66 / 30 50 40 40
Salina 90 66 85 67 / 30 40 30 50
McPherson 88 66 86 66 / 30 30 30 40
Coffeyville 90 68 89 69 / 10 10 20 30
Chanute 90 67 87 67 / 30 10 20 40
Iola 89 66 86 67 / 40 10 20 50
Parsons-KPPF 89 68 88 68 / 20 10 20 40
&&
.ICT Watches/Warnings/Advisories...
None.
&&
$$
SHORT TERM...RBL
LONG TERM...RBL
AVIATION...RBL
Area Forecast Discussion
National Weather Service Wichita KS
625 AM CDT TUE JUN 28 2016
.SYNOPSIS...
Issued at 228 AM CDT Tue Jun 28 2016
In the upper levels, ridging is centered over the four corners
region with a shortwave diving southeast over the western Great
Lakes. At the surface, high pressure is situated over ND/northern
MN with a loose cold front stretching across northern MO into
northern KS.
&&
.SHORT TERM...(Today through Friday night)
Issued at 228 AM CDT Tue Jun 28 2016
Just like last night, have low confidence in what is forcing
convection over northern KS as elevated parcels remain uncapped.
Best guess is that a weak upper impulse, convectively induced or
not, is what sparked off storms over far northern KS/southern
Nebraska. Will continue to monitor trends too see if this small
complex holds together, as we may need to increase pops over
central KS this morning.
Outside of this morning activity, should see a setup fairly
similar to what played out Mon, with the high Plains of
KS/Nebraska seeing the bulk of the daytime convection. These
storms should track southeast overnight and possibly a bit further
east compared to Mon evenings storms due to the better moisture
transport being pushed slightly east. Will keep with the overall
theme of keeping the highest storm chances along and especially
west of I-135. Feel that best the chance for storms Wed looks to
be Wed morning as the overnight storms continue to push southeast.
Northwest flow will remain over the Plains for Wed through Thu
night. There is a good signal that another round of elevated
convection will develop Wed night in an area of strong isentropic
lift in the 310-315k layer. 700mb temps also show a fairly tight
gradient through the forecast area with some warm advection over
this baroclinic zone.
For Thu into Thu night, there is good model agreement in a cold
front sliding down into the central Plains with this feature
stretching from northern MO into SW KS by 00z Fri. At the same
time, models also agree on some upper energy lifting out of the
desert sw and across the area for Fri into Fri night. The
combination of the front and a series of weak impulses will keep
decent storm chances in for Thu night through Fri night with
the southern half of KS looking to have the better chances.
Temps will finally start to cool to closer to or just below
seasonal normals. Most of the area should see 80s for highs for
Thu with much cooler air moving down across the region for Fri.
.LONG TERM...(Saturday through Monday)
Issued at 228 AM CDT Tue Jun 28 2016
Will keep fairly high storm chances in for Sat as the zonal
pattern remains active with models showing additional pieces of
energy lifting out of the four corners region. In addition, the
weak surface boundary looks to remain over the area through Sun
morning. There looks to be some agreement in the medium range
models in some weak upper ridging over the central/southern
Plains for Sun night into Mon, which should push the better precip
chances east.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 618 AM CDT Tue Jun 28 2016
Main aviation concern will be storms this morning and again later
tonight.
Storms developed over extreme north central KS a few hours ago.
Tough to find the forcing for these storms but best guess is that
this activity is developing ahead of a weak upper impulse diving
southeast in the NW flow. Current thinking is that this activity
will continue for at least the next few hours. Will include
either a tempo group or vcts at all sites this morning with the
exception of KICT. Late afternoon storms are expected to develop
once again over western Nebraska with this activity diving
southeast overnight. Areas generally west of I-135 will have the
best chance to see overnight storms, so will run with VCTS after
03z at KRSl-KGBD-KSLN.
There has been some periodic fog at KCNU early this morning but
with sun coming up and storms approaching, not expecting this to
last much longer.
Lawson
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 90 68 86 69 / 20 20 20 40
Hutchinson 88 67 87 67 / 20 30 30 40
Newton 89 67 86 67 / 30 20 20 40
ElDorado 89 68 86 67 / 30 20 20 40
Winfield-KWLD 90 69 88 69 / 20 10 20 30
Russell 89 66 85 65 / 40 50 50 50
Great Bend 89 66 86 66 / 30 50 40 40
Salina 90 66 85 67 / 30 40 30 50
McPherson 88 66 86 66 / 30 30 30 40
Coffeyville 90 68 89 69 / 10 10 20 30
Chanute 90 67 87 67 / 30 10 20 40
Iola 89 66 86 67 / 40 10 20 50
Parsons-KPPF 89 68 88 68 / 20 10 20 40
&&
.ICT Watches/Warnings/Advisories...
None.
&&
$$
SHORT TERM...RBL
LONG TERM...RBL
AVIATION...RBL
[top]
Area Forecast Discussion
National Weather Service Dodge City KS
604 AM CDT TUE JUN 28 2016
...UPDATE TO AVIATION...
.SHORT TERM...(Today and tonight)
Issued at 325 AM CDT Tue Jun 28 2016
The northwest flow pattern is underway, and along with it a
challenging forecast. At the time of this writing at 0800 UTC, there
were two small MCSs, one across far eastern Colorado and adjacent
far western KS with a second one across far north central KS. It
looks like a majority of the southwest KS region will avoid both of
these MCSs as they track almost due south. The exception will be the
western six counties were some rainfall of around a quarter inch can
be expected with some locally higher amounts through the mid-morning
hours before the MCS weakens. Some of the hourly HRRR runs want to
merge the two MCSs, so that will have to be watched later in the
morning, but right now that doesn`t seem to be happening, so we will
be keeping POPs fairly low with the exception of far southwest and
west central KS.
It is unclear exactly how convection will evolve late this afternoon
through tonight. We could see a repeat of yesterday, except starting
off a bit farther north in Nebraska. A mature MCS never really
materialized last night like was forecast, however that does not
mean that one large, cohernet, long-lived MCS won`t happen tonight.
Signals are certainly there in both the high resolution convective
allowing models and lower resolution models. The NAM12 is
particularly bullish, showing a significant QPF signal rolling SSE
from western Nebraska into southwest KS by 12z Wednesday. Both the
NCEP WRF-ARW and WRF-NMMB show something coherent rolling across the
same generally area before decaying around or shortly after 09z
Wednesday. In the official forecast, we will have 40-50 POPs going
mainly east and north of a Dighton-Dodge-Greensburg-Pratt line with
greatest confidence and QPF forecast values up along the I-70
corridor.
.LONG TERM...(Wednesday through Monday)
Issued at 325 AM CDT Tue Jun 28 2016
The active northwest flow pattern will continue through the end of
the week. A couple of things that will probably act to enhance
precipitation coverage and intensity later in the week will be 1) a
fairly decent surface front which will slow down and perhaps become
quasi-stationary across southern Kansas and 2) some minor mid level
perturbations/enhanced mid level moisture rotating around weak
ridging, thanks to abundance of mountain convection across the
southern Rockies. POPs in the Long Term will be highest Thursday
Night through Saturday Night with 12-hr POPs every period in the 40-
60 percent territory somewhere across our forecast area from west
central KS through south central KS. It still looks as though some
areas will see potentially excessive rainfall once the polar front
gets down here, given all the moisture that will be around and the
generally weak mid-upper level flow leading to slow-moving
convection.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 602 AM CDT Tue Jun 28 2016
VFR conditions will prevail at all TAF sites through early this
evening. Light and variable winds will turn southeasterly 10 to
20kt this afternoon as a lee side trough of low pressure strengthens
across eastern Colorado today.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 88 67 90 66 / 20 40 20 30
GCK 89 66 91 66 / 20 30 20 20
EHA 90 67 94 66 / 40 20 20 30
LBL 91 67 94 67 / 30 20 20 30
HYS 87 66 86 65 / 20 50 40 40
P28 90 68 90 69 / 10 30 30 40
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Umscheid
AVIATION...JJohnson
Area Forecast Discussion
National Weather Service Phoenix AZ
305 PM MST TUE JUN 28 2016
.UPDATE...
Updated Aviation and Fire Weather sections.
&&
.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...
Tonight through Saturday...
Model guidance and water vapor imagery showed the slow moving
inverted trof coming out of the Gulf of CA into an area near the
Mexican border south of Tucson this afternoon. At the same time,
high speed visible satellite imagery showed a mid level disturbance
moving toward southeast AZ from southern New Mexico. As a result 2
pm radar and satellite imagery showed a growing area of
thunderstorms from Tucson southward. At the same time there were
developing thunderstorms over the higher terrain of central AZ north
of Phoenix. Meso-scale models forecast gusty outflow winds to move
toward Phoenix late today sparking mtn convection east of Phoenix,
followed by a stronger outflow boundary from the Tucson area late
this evening. As a result, convective outflows and or colliding
boundaries could generate a threat of showers and thunderstorms
around the greater Phoenix area tonight, similar to last night when
Sky Harbor Airport recorded 0.01 inches of rain with heavier amounts
around the city. Our southeast CA and southwest AZ zones will be dry
for the most part tonight.
Another and perhaps stronger upper level disturbance is forecast to
move from just off the central Baja west coast tonight, into
southern AZ late Wednesday afternoon. Interesting is the MOS precip
guidance is forecasting a higher probability of precipitation over
the south central AZ, including Phoenix Wednesday evening.
More recognizable upper level disturbances, like those currently
seen on water vapor imagery 650 miles southwest of San Diego, are
forecast to move into southern AZ Thu and Fri. Timing of these
disturbances are uncertain, and with the monsoon moisture in place,
a broad brush chance approach to afternoon and evening thunderstorms
is perhaps the best approach for now. The threat of tstms will be
primarily confined to portions of southwest and south central AZ for
the tonight through Saturday period.
Sunday through Tuesday...
Models are forecasting a somewhat airmass to overspread our forecast
area, southeast CA to south central AZ, from the west this period.
Although drier air pushes into southeast CA and the Colorado River
Valley, south central and southeast AZ will still hang on to some
remnant moisture. The monsoon moisture boundary retreats east
into the far southeast corner of AZ Mon and Tue.
However perhaps more importantly Monday through Wednesday is a major
adjustment in the upper level flow pattern. Winds at and above 300
mb become broadly anti-cyclonic, devoid of disturbances, and
certainly imply a very stable subsident airmass that could kill the
threat of afternoon/evening high elevation mountain storms.
Therefore this period will be a quiet one, meaning mostly clear
skies, warmer afternoon temperatures, with just a very slight chance
of an afternoon mountain thunderstorms in southern Gila County
bordering the White Mountains.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Thunderstorms developing north through southeast of metro Phoenix
will likely increase in coverage (especially over Gila County)
through 00Z. Outflow from distant storms will likely affect at least
some portion of metro Phoenix this evening - most likely after 02Z.
Confidence in storms directly hitting any given TAF site not high
enough yet to include TEMPO or prevailing TSRA. However, TAFs
reflect the scenario of nearby storms causing erratic winds this
evening. There are some indications that lingering shower/storm
activity could go til 09Z. But by that point, likely this would only
be debris clouds (bases AOA FL100) with otherwise light winds.
Anticipate debris clouds lingering well past sunrise. Anticipate
southeasterly surface winds to last for much of the day with
westerly struggling to develop in the afternoon.
Southeast California/Southwest Arizona including KIPL and KBLH:
A stray thunderstorm is quite possible (mainly over La Paz County)
through 06Z otherwise anticipate debris clouds (bases AOA FL100)
with isolated weak showers after 03Z (mainly near and east of Lower
Colorado River Valley). Surface winds will favor south and
southeasterly directions (being stronger Wednesday than today).
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Thursday through Tuesday...
Enhanced humidities and storm chances will continue into Saturday.
Humidities will trend down substantially Sunday and Monday. In fact,
minimum humidities on the low deserts will be near 10 percent by
Monday. Similarly, overnight recovery will trend down to only fair.
Thunderstorm chances will be confined to the higher terrain of south-
central AZ Sun-Tue and be only slight. Apart from strong erratic
winds associated with thunderstorms, southerly breeziness can be
expected over southwest AZ and southeast CA Thu-Sat(less so over
south-central AZ). Winds will favor southwesterly directions next
week.
&&
.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...AJ
FIRE WEATHER...AJ
[top]
Area Forecast Discussion
National Weather Service Tucson AZ
300 PM MST TUE JUN 28 2016
.SYNOPSIS...Scattered showers and thunderstorms will occur through
tonight, with the favored areas south of Tucson and across the White
Mountains. Increasing moisture and a favorable flow regime will then
provide even greater coverage of showers and thunderstorms Wednesday
through Friday. A drying trend will then limit thunderstorms to
mainly near the New Mexico border by early next week.
&&
.DISCUSSION...Visible satellite imagery and KEMX WSR-88D showed
isolated to scattered convection this afternoon, mainly south and
west of I-10. So far the storms seem to be relatively tame, since
they are being sheared apart by low level easterly flow and upper
level southwesterly flow. It`s still feeling soupy out there with
sfc dewpoints holding steady in the 50s. 28/18z CIRA LPW indicated
the bulk of moisture was located near the international border and
across the western half of Pima County. Not as much activity as
anticipated over the White Mountains, but the latest runs of the
HRRR/WRFEMS are hinting at convection developing over that area
later on this evening, so there`s still time. Overall, it still
looks like scattered showers and thunderstorms will continue into
this evening, with isolated activity into the overnight hours.
The 28/12Z runs of the GFS/ECMWF remain in very good agreement
through at least the first part of the holiday weekend. The
anticipation is for an upswing in convective activity starting
tomorrow, with a focus on Thursday into Friday especially. High
pressure aloft currently located near the preferred Four Corners
region will remain quasi-stationary through tomorrow, with a shift
toward the east and southeast through the end of the work week. In
response, expect upper level flow to becoming increasingly
southeasterly and then southerly, which will really aid in ramping
up our moisture in the form of a Gulf surge. As such, wouldn`t be
surprised to see sfc dewpoints jump into the mid to upper 60s as
early as Wednesday night into Thursday morning. In addition, the
GFS/NAM indicate PWAT will jump to between 1.6 and 2 inches by
00Z Friday, with the highest values across western Pima County.
Thereafter, PWAT values look to drop to around 1.25 inches by 12z
Saturday, and continue to decrease into early next week as we lose
our monsoonal flow and a weak upper ridge/westerly flow develops
over the southwestern deserts. This will shut us down for a few days
with regard to convection, with the exception being areas adjacent
to the NM border and across the mountains. The GFS then tries to
reconsolidate high pressure over the four corners while the ECMWF
maintains westerly flow. As such, have continued with just slight
chance PoPs for eastern zones at the end of the forecast period. We
will also have to keep an eye on the tropics, as both the GFS/ECMWF
bring a system southwest of the Baja tip late next week. Something
to watch.
Expect a slow decrease in daytime temperatures through Friday, when
highs will top out 5-10 degrees below normal. We will then warm
right back up to normal levels by Sunday into early next week.
&&
.AVIATION...VALID THRU 30/00Z.
Scattered showers and thunderstorms will be in and around the
terminals through 29/08Z. KTUS, KDUG, and KOLS have the best chance
of seeing activity. VFR conditions will be the rule, however, brief
MVFR conditions in heavy rainfall are possible. Additionally, wind
gusts upwards of 30 kts will be possible in and around the strongest
storms. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...With plenty of moisture and instability we
will have daily rounds of scattered showers and thunderstorms
through Friday. The strongest storms will be capable of very strong
winds and heavy downpours especially during the mid afternoon to
early evening hours. Moisture will diminish across the region
Saturday onward resulting in a decrease in the amount of convection
each day. By Monday any isolated convection will be limited to the
mountains near the eastern border and over the White Mountains.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
DISCUSSION...French
AVIATION/FIRE WEATHER...Cantin
Area Forecast Discussion
National Weather Service Phoenix AZ
226 PM MST TUE JUN 28 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...
Tonight through Saturday...
Model guidance and water vapor imagery showed the slow moving
inverted trof coming out of the Gulf of CA into an area near the
Mexican border south of Tucson this afternoon. At the same time,
high speed visible satellite imagery showed a mid level disturbance
moving toward southeast AZ from southern New Mexico. As a result 2
pm radar and satellite imagery showed a growing area of
thunderstorms from Tucson southward. At the same time there were
developing thunderstorms over the higher terrain of central AZ north
of Phoenix. Meso-scale models forecast gusty outflow winds to move
toward Phoenix late today sparking mtn convection east of Phoenix,
followed by a stronger outflow boundary from the Tucson area late
this evening. As a result, convective outflows and or colliding
boundaries could generate a threat of showers and thunderstorms
around the greater Phoenix area tonight, similar to last night when
Sky Harbor Airport recorded 0.01 inches of rain with heavier amounts
around the city. Our southeast CA and southwest AZ zones will be dry
for the most part tonight.
Another and perhaps stronger upper level disturbance is forecast to
move from just off the central Baja west coast tonight, into
southern AZ late Wednesday afternoon. Interesting is the MOS precip
guidance is forecasting a higher probability of precipitation over
the south central AZ, including Phoenix Wednesday evening.
More recognizable upper level disturbances, like those currently
seen on water vapor imagery 650 miles southwest of San Diego, are
forecast to move into southern AZ Thu and Fri. Timing of these
disturbances are uncertain, and with the monsoon moisture in place,
a broad brush chance approach to afternoon and evening thunderstorms
is perhaps the best approach for now. The threat of tstms will be
primarily confined to portions of southwest and south central AZ for
the tonight through Saturday period.
Sunday through Tuesday...
Models are forecasting a somewhat airmass to overspread our forecast
area, southeast CA to south central AZ, from the west this period.
Although drier air pushes into southeast CA and the Colorado River
Valley, south central and southeast AZ will still hang on to some
remnant moisture. The monsoon moisture boundary retreats east
into the far southeast corner of AZ Mon and Tue.
However perhaps more importantly Monday through Wednesday is a major
adjustment in the upper level flow pattern. Winds at and above 300
mb become broadly anti-cyclonic, devoid of disturbances, and
certainly imply a very stable subsident airmass that could kill the
threat of afternoon/evening high elevation mountain storms.
Therefore this period will be a quiet one, meaning mostly clear
skies, warmer afternoon temperatures, with just a very slight chance
of an afternoon mountain thunderstorms in southern Gila County
bordering the White Mountains.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL: For the
morning into the afternoon, expect winds to favor the southeast at
the terminals, mostly below 12kt with a slight tendency to then turn
towards the west. Variable mid/high level cloud decks will move
across the greater Phoenix area with most bases aoa 12k feet and
most broken decks aoa 15k feet. May see a few light showers or virga
from these decks this morning. Once again expect mountain
thunderstorms to develop east of Phoenix later this afternoon and
evening, a few of which may move into the central deserts and affect
the terminals after 03z or so. Will not get overly aggressive in the
TAFs this early and will stick with VCTS for now. Have added in
earlier than usual switch to east/southeast winds at the TAF sites,
mostly after 04z based on expected outflow winds moving into the
lower deserts.
Southeast California/Southwest Arizona including KIPL and KBLH: Most
convective weather to stay east of the area today and into the
evening hours with skies to be mostly sunny. Most cloud decks to be
few to sct with bases above 12k feet. Winds will be rather light
next 24 hours and occasionally variable but favoring the southeast
to south, likely turning back towards the west this evening at KIPL.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Thursday through Monday... Temperatures will continue to cool as
moisture increases, with south central Arizona lowering below 105
degrees and even below 100 after Thursday and into the weekend.
Modest warming expected later in the period as air mass dries a bit.
Monsoon moisture levels continue to increase over the region with
chances for afternoon thunderstorms expected across south central
Arizona through Friday and slight chances further west towards the
lower Colorado River valley. Over the weekend and into early next
week a drying trend from the west is expected and by Sunday isolated
thunderstorms should be mostly confined to higher terrain areas to
the east of Phoenix. Any storms that develop have the ability to
produce lightning, gusty winds, and wetting rains, especially
storms that develop across south central Arizona through Friday.
Minimum humidities through Friday will be highly elevated,
especially west of the lower Colorado River valley, with readings
generally 20 to 30 percent, and even higher across southern Gila
County. Readings will fall between 15 and 20 percent Saturday, then
down mostly below 15 percent Sunday into Monday as drier air spreads
over the area from the southwest. Winds each day will be on the
light side for the most part, mostly below 15 mph, but will be
locally breezy at times from the south west of Maricopa county and
along the lower Colorado River valley mainly during the afternoon
hours each day.
&&
.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...CB
FIRE WEATHER...Deemer/CB
[top]
Area Forecast Discussion
National Weather Service Flagstaff AZ
946 AM MST TUE JUN 28 2016
.SYNOPSIS...Monsoon activity will be on the increase over the next
few days as a moist southerly flow develops across Arizona. Look
for showers and thunderstorms each day with the best potential for
heavy rain arriving on Thursday and Friday.
&&
.DISCUSSION...This morning`s sounding from near Flagstaff, AZ
reveals precipitable water is up a bit as compared to this time
yesterday. In addition, surface dew points are up a few degrees
at most places. With that said, forecast soundings indicate that a
mid-level stable layer may develop later today in the wake of
passing shortwave trough skirting northwestern Arizona. Will need
to monitor this feature as it would aid in suppressing convection
later this afternoon.
With that said, today`s storm motion will generally be from the
southeast to northwest. The high based nature of today`s storms
will make strong outflow winds in the 30 to 50 mph range the
primary threat, followed by brief/localized downpours under the
stronger cells.
In terms of forecast updates, made a couple short-term grid
updates to account for a line of showers over central Coconino
County. These showers are associated with the previously mentioned
shortwave trough, which is due to exit the region around noon or
so.
&&
.PREV DISCUSSION /241 AM MST/...For Wednesday through
Friday...The high center gradually shifts to a position over Texas
with southerly flow developing across Arizona. The southerly flow
pattern will be favorable for deep moisture over Northwest Mexico
and the Gulf of California to move northward. In addition, there
will be a good chance for a convective blow-up in Mexico (known as
a mesoscale convective complex) which could induce a Gulf of
California surge pushing additional moisture into the state. We`ll
be keeping and eye on Thursday and Friday because those two days
show the best potential for storms producing extremely rain.
From Saturday onward...The flow becomes more westerly with origins
from over the eastern Pacific Ocean. Under this regime look for a
bit of drying and stabilization with a downturn in thunderstorm
activity anticipated.
&&
.AVIATION...For the 18Z Package...An area of mainly light rain and
isolated thunderstorms will affect the KGCN TAF site and points NW
through 19z. Otherwise, expect sct-numrs shra/tsra and isold +tsra
from 19z-02z today. Coverage becmg isold aft 02z. The strongest
storms may produce mvfr conditions with heavy rain, small hail and
wind gusts to 45kts. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...An active monsoon pattern is now in place across the
district. This means daily shower and thunderstorm activity. Storm
motion will be from southeast to northwest today, then becoming
nearly stationary and terrain driven by Wednesday. Expect erratic
and gusty winds near showers and storms.
Thursday through Saturday...Expect active monsoon weather with
scattered showers and thunderstorms each day. Temperatures will be
right around seasonal averages.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...RR/McCollum
AVIATION...Peterson
FIRE WEATHER...MCS
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Tucson AZ
905 AM MST TUE JUN 28 2016
.SYNOPSIS...Scattered showers and thunderstorms will occur through
tonight, with the favored areas south of Tucson and across the White
Mountains. Increasing moisture and a favorable flow regime will then
provide even greater coverage of showers and thunderstorms Wednesday
through Friday. A drying trend will then limit thunderstorms to
mainly near the New Mexico border by early next week.
&&
.DISCUSSION...Visible satellite imagery this morning
indicated scattered mainly cumuloform clouds across southeast
Arizona. Area sfc temperatures as of 28/15z were generally in the
upper 80s to lower 90s through the valleys with cooler temperatures
across the sky islands. It was feeling a little sticky with sfc
dewpoints holding steady in the 50s with a few spots in the low 60s.
28/12z KTWC RAOB indicated generally light ely flow below about H5
with swly flow above, and PWAT of 1.42 inches. Still looking at
scattered showers and thunderstorms this afternoon/evening across
areas mainly southwest-to-southeast of Tucson, and the White
Mountains. This notion was supported by various Hi-Res NWP models
including the HRRR and the UA-WRFNAM/WRFGFS. With the bulk of
moisture below H4 and DCAPE of almost 1200 J/kg, we will have to
watch for gusty outflows/microbursts with any storms that develop.
The current forecast is handling all trends well this morning...so
no updates are planned. Please see the additional sections for
further details.
&&
.AVIATION...VALID THRU 29/18Z.
Scattered to broken clouds in multiple layers expected ranging from
10k-15k ft agl with isold -SHRA/-TSRA this morning and scattered
TSRA/SHRA this afternoon and evening. Diurnal surface winds of 12
kts or less expected through the period outside of thunderstorms.
Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...With plenty of moisture and instability we
will have daily rounds of scattered showers and thunderstorms
through Friday. The strongest storms will be capable of very strong
winds and heavy downpours especially during the mid afternoon to
early evening hours. The moisture will diminish across the region
Saturday onward resulting in a decrease in the amount of convection
each day. By Monday any isolated convection will be limited to the
mountains near the eastern border and over the White Mountains.
&&
.PREV DISCUSSION...Scattered showers and thunderstorms are expected
to return this afternoon and evening. The favored locales for these
showers and thunderstorms are southwest-to-southeast of Tucson, and
across the White Mountains. PoPs have been adjusted to reflect this
expectation. Enough moisture will exist for at least isolated
coverage of showers/tstms late tonight.
28/00Z GFS/ECMWF/CMC remain in very good agreement in depicting an
upswing in showers and thunderstorms starting Wednesday, and
particularly Thursday into Friday. High pressure aloft presently
centered near the Four Corners region will remain quasi-stationary
through Wednesday, then the upper high is progged to shift sewd and
become centered over central Texas around daybreak Friday. A fairly
deep easterly flow regime over this forecast Wednesday should become
increasingly sely Thursday, then more sly Friday. Am anticipating
ample moisture from the Gulf of California (a.k.a. Gulf of
California surge) to advect into southern Arizona by early Thursday.
Have noted that the deterministic GFS depicted precip water values
mainly around 1.30 - 1.40 inches or so today, increasing to 1.40 -
1.60 inches or so Wednesday, then 1.40 - 1.80 inches by Thursday.
The largest values are progged to be across western sections.
At any rate, the combination of ample moisture and a favorable flow
regime should provide scattered to numerous showers and
thunderstorms, especially during the afternoon/evening hours.
Somewhat less coverage of showers/tstms is forecast to occur in the
late night/early morning periods. Deep moisture over the area Friday
will be shunted eastward into New Mexico Saturday as generally wly
flow becomes established over the area. The ECMWF continued with a
generally wly flow aloft regime Sun-Mon, but the GFS the mid-level
flow to become ely by next Mon. At any rate, for this forecast
package have continued with the notion of a drying trend and
corresponding decrease in shower/tstm coverage Sun-Mon. Thus,
isolated to perhaps scattered coverage of showers/tstms Sunday, then
a slight chance of showers/tstms limited to mainly near the
mountains east and south of Tucson Monday.
Expect markedly lower daytime temps by Friday followed by a warming
Sat-Mon.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
DISCUSSION...French
PREV DISCUSSION...Francis
AVIATION/FIRE WEATHER...Cerniglia
AREA FORECAST DISCUSSION
National Weather Service San Diego CA
136 PM PDT TUE JUN 28 2016
.SYNOPSIS...
High pressure aloft will continue hot weather inland through
Wednesday...followed by slow cooling into Saturday as high
pressure aloft weakens and a weak low pressure trough develops
along the coast. A disturbance, in addition to moisture aloft and
weak instability, will continue to produce a slight chance for
showers and thunderstorms over the mountains, high deserts, and
Coachella valley through early evening. Residual moisture will
produce a slight chance of afternoon and early evening mountain
and high desert thunderstorms Wednesday. Main threats from
thunderstorms are dry lightning and gusty winds. The marine layer
and onshore flow will keep coastal high temperatures lower with
areas of night and morning low clouds and fog. Another warm-up may
begin on Sunday.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Water vapor satellite currently indicates an upper level wave
slowly drifting north over San Bernardino county, with a ridge
over the four corners area. Currently, radar indicates some
thunderstorms over the San Gorgonio Wilderness/Big Bear area, and
some sprinkles over the High Deserts. Meanwhile, visible
satellite shows that marine layer stratus has cleared out of
inland areas, but is sticking to the coast due to the strong 13
deg C inversion shown by the 12Z Miramar sounding. The sounding
also shows significant drying, with the precipitable water having
dropped to 0.86 inches, compared to 1.48 inches yesterday.
The wave will lift north through the day today. Latest SPC
mesoanalysis shows an area of 500 J/KG of MUCAPE over the
mountains, and NAM12 shows this amount of instability continuing
through early evening. Thus, hi-res models and the HRRR focus any
shower/thunderstorm activity over those areas, as well as the High
Deserts.
Meanwhile, with the strong ridge over the region today, it is hot
once again in the valleys, mountains and deserts. Temperatures
have risen to the low 110s in the lower deserts, low 100s in the
Inland Empire, mid to high 90s in the lower mountain slopes, and
low to mid 90s in the San Diego county valleys. However, warming
has been slower in the High Deserts due to the higher amount of
cloud cover in that area. Expect highs to rise to 5-10 degrees,
and locally 15 degrees, above normal today. Meanwhile, local WRF
shows the marine layer remaining at a similar depth tonight, if
not slightly deeper, with stratus/fog moving into the coast and
western valleys.
Precipitable water stays down around 0.8 inches on Wednesday, but
there may be enough residual moisture to produce isolated
thunderstorms over the mountains during the afternoon and early
evening. The ridge stays similarly strong over our region on
Wednesday, so the hot conditions will continue for inland areas.
The Heat Advisory remains in effect for the Inland Empire,
mountains and deserts through 8 PM Wednesday. Southwest flow aloft
will produce further drying on Thursday, so any thunderstorm
activity that day is unlikely. The ridge also starts to weaken on
Thursday as a trough moves in over the West coast, so it should
start to cool a bit with also some deepening of the marine layer.
Cooling and a deeper marine layer likely to continue Friday and
Saturday due to the trough. Models are showing that the flow aloft
on Friday turns more southerly, as opposed to southwesterly, and
this may allow enough moisture to squeeze into the region for
possible afternoon thunderstorms/showers over the mountains. We
may start to heat up again Sunday into early next week, as the GFS
shows the ridge rebuilding over the region. However, the ECMWF
keeps us cooler with a trough along the west coast.
&&
.AVIATION...
281945Z...Coast/Valleys...BKN-OVC low clouds based 700-1000 feet
MSL with tops to near 1200 feet MSL over the coastal waters and
at most beaches otherwise mostly clear. Stratus will push inland
over coastal airports this evening around 29/06z with
little change in heights. Risk of low clouds returning as a solid
deck this evening is moderate-high so confidence in the KSAN TAF
timing is also moderate-high. Local visibilities at or below
3 miles in fog and haze inland edge of the low clouds is expected
around 10-15 miles inland.
Isolated SHRA/TSRA mainly near the mountains through 29/00z
this afternoon with CB bases near 9000 ft MSL and tops
to near 35000 ft MSL along with local surface gusts to near
30 knots.
Mountains and Deserts...Isolated showers with bases mostly above
10000 ft MSL and little impact on VIS will occur over San
Bernardino County and the San Jacinto Mountains with tops to
35000 ft MSL and local surface gusts over 30 knots.
Otherwise, SCT-BKN clouds today at/above 10000 ft
MSL will dissipate tonight with unrestricted VIS.
&&
.MARINE...
130 pm...No hazardous marine weather is expected through Saturday.
&&
.BEACHES...
130 pm...Long period southerly swells will increase again late
Wednesday into Thursday, with the predominant swell 4 feet/17
seconds/200 degrees. This will bring 4-6 foot surf to southwest
facing beaches late Wednesday through Friday along with dangerous
rip currents.
&&
.FIRE WEATHER...
An upper level disturbance will continue to produce a slight
chance of dry lightning over Southwest San Bernardino county, the
Riverside county mountains and deserts, and the northern San Diego
county mountains through early this evening. Enough residual mid-
level moisture may be around for some isolated thunderstorm
and dry lightning activity Wednesday afternoon and evening over
the mountains and high deserts. Thunderstorms will also produce
gusty and erratic downdraft winds. Thunderstorms are unlikely
Thursday, but there are some indications that there could be some
activity on Friday.
&&
.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 San Diego CA
925 AM PDT TUE JUN 28 2016
.SYNOPSIS...
High pressure aloft will continue hot weather inland through
Wednesday...followed by slow cooling into next weekend as high
pressure aloft weakens and a weak low pressure trough develops
along the coast. A disturbance, in addition to moisture aloft and
weak instability, will continue to produce a slight chance for
showers and thunderstorms over the mountains, high deserts, and
Coachella valley through early evening. Residual moisture will
produce a slight chance of afternoon and early evening
mountain thunderstorms Wednesday. Main threats from thunderstorms
are dry lightning and gusty winds. 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...
Water vapor satellite currently indicates an upper level wave
slowly drifting north over San Bernardino county, with a ridge
over the four corners area. A lightning strike occurred near
Daggett earlier, and then over the past couple hours some
thunderstorms producing numerous lightning strikes developed over
the Coachella Valley. Otherwise, some sprinkles are occurring
over Southerwestern San Bernardino county mountains. Meanwhile,
visible satellite shows marine layer stratus over the coastal
waters and coastal areas, with some stratus/fog making it into the
western valleys. The 12Z Miramar sounding shows a strong marine
layer inversion of 13 deg C at 1000 ft msl, which means that the
stratus will likely have a difficult time of clearing at the
immediate coast today. The sounding also shows significant drying,
with the precipitable water having dropped to 0.86 inches,
compared to 1.48 inches yesterday.
The wave will lift north through the day today. The NAM12 shows
instability decreasing later in the morning, but then increasing
again in the afternoon over the mountain peaks of San Bernardino
and Riverside county, with MUCAPE in the 700-300 mb layer reaching
near 400 J/KG. Thus, hi-res models and the HRRR focus any
shower/thunderstorm activity over those areas, as well as the High
Deserts. Given the early morning thunderstorm activity in the
Coachella Valley, have updated the forecast to include
thunderstorms for that area and also the Inland Empire this
morning and this afternoon, and also northern portions of the San
Diego county mountains for this afternoon.
Meanwhile, with the strong ridge over the region today, it will be
hot once again in the valleys, mountains and deserts, while the
marine layer keeps it relatively cooler at the coast. Expect highs
to rise to 5-10 degrees, and locally 15 degrees, above normal
today. Mid 60s dewpoints in the valleys will also make it feel
muggy and uncomfortable. However, with the cloud cover this
morning over San Bernardino county and Riverside county, those
areas may stay a bit cooler than expected. Local WRF shows the
marine layer remaining at a similar depth tonight, if not slightly
deeper, with stratus/fog moving into the coast and western
valleys.
Precipitable water stays down around 0.8 inches on Wednesday, but
there may be enough residual moisture to produce isolated
thunderstorms over the mountains during the afternoon and early
evening. The ridge stays similarly strong over our region on
Wednesday, so the hot conditions will continue for inland areas.
The Heat Advisory remains in effect for the Inland Empire,
mountains and deserts through 8 PM Wednesday. Southwest flow aloft
will produce further drying on Thursday, so any thunderstorm
activity that day is unlikely. The ridge also starts to weaken on
Thursday as a trough moves in over the West coast, so it should
start to cool a bit and also some deepening of the marine layer is
likely.
Cooling and a deeper marine layer likely to continue Friday and
Saturday due to the trough. We may start to heat up again Sunday
into early next week, as the GFS shows the ridge rebuilding over
the region. However, the ECMWF keeps us cooler with a trough along
the west coast.
&&
.AVIATION...
281610Z...Coast/Valleys...BKN-OVC low clouds based 700-1000 feet
MSL with tops to near 1200 feet MSL over the coastal waters and
at most beaches otherwise mostly clear. Stratus will redevelop
over coastal airports this evening around 29/06z with
little change in heights. Risk of low clouds returning as a solid
deck this evening is moderate-high so confidence in the KSAN TAF
timing is also moderate-high. Local visibilities at or below
3 miles in fog and haze inland edge of the low clouds is expected.
Isolated SHRA/TSRA mainly near the mountains through 29/00z
this afternoon with CB bases near 9000 ft MSL and tops
to near 35000 ft MSL along with local surface gusts to near
30 knots.
Mountains and Deserts...Isolated showers with bases mostly above
10000 ft MSL and little impact on VIS will occur over San
Bernardino County and the San Jacinto Mountains with bases 9000 ft
MSL and tops to 35000 ft MSL and local surface gusts over 30 knots.
Otherwise, SCT-BKN clouds today at/above 10000 ft MSL will dissipate
tonight with unrestricted VIS.
&&
.MARINE...
930 am...No hazardous marine weather is expected through Saturday.
&&
.BEACHES...
930 am...Long period southerly swells will increase again late
today into Thursday, with the predominant swell 4 feet/17
seconds/200 degrees. This will bring 4-6 foot surf to southwest
facing beaches late Wednesday through Friday along with dangerous
rip currents.
&&
.FIRE WEATHER...
An upper level disturbance will continue to produce a slight
chance of dry lightning over Southwest San Bernardino county, the
Riverside county mountains and deserts, and the northern San Diego
county mountains through early this evening. Enough residual mid-
level moisture may be around for some isolated thunderstorm
and dry lightning activity Wednesday afternoon and evening over
the mountains. Thunderstorms will also produce gusty and erratic
downdraft winds. The thunderstorm threat should end after
Wednesday.
&&
.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
1214 PM CDT TUE JUN 28 2016
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 411 AM CDT TUE JUN 28 2016
A complex of thunderstorms continued to move southeast early this
morning, showing signs of intermittent severe downburst winds.
Overall parameters are not particularly favorable for severe storms,
but the organized cold pool has been able to interact with elevated
instability and modest deep layer wind shear to provide periods of
intensification and organization of rear inflow jets and downdraft
surges. It is these features that will continue to be monitored for
severe wind potential...and severe hail is a minimal secondary
hazard along with locally heavy rain. These storms have become
organized enough that they seem to be developing a convectively
enhanced MCV aloft, and would expect this feature to move southeast
with the storms and probably continue to enhance convection and
rainfall rates...and also steer the motion of the storms a bit.
Expect storms to gradually diminish and move out of the area by mid
to late morning. Beyond that time, should see mainly dry conditions
through the rest of the day. Additional storms will likely develop
in Nebraska and move south and southeast into the evening but there
is some uncertainty in whether they will have sufficient instability
to progress into northeast KS, and chances seem pretty low. A more
organized MCS is likely to develop farther west, and remain mainly
west of the forecast area through the evening although the eastern
fringes could stretch into north central KS. Then later on tonight,
additional forcing moves across eastern Nebraska...and again may be
able to support storms into central and eastern KS closer to sunrise
but instability should be weak and severe potential seems quite
low or nil from noon today at least through tonight.
.LONG TERM...(Wednesday through Monday)
Issued at 411 AM CDT TUE JUN 28 2016
Overall extended period remains unsettled with an active pattern of
weak embedded troughs traversing through the region, bringing
multiple chances for convection through Sunday. There are a few
periods where confidence in precip increases with a more optimal
forcing mechanism Thursday evening through Saturday evening.
Otherwise, confidence is fairly low in coverage of pops - highly
dependent on mesoscale factors that mid term models are unable to
discern this far out.
Convection on Wednesday afternoon and evening, mainly focuses over
north central areas. Timing of convection on Tuesday evening will
dictate this scenario as the NAM continues to be highlighting an MCS
over western KS during this time, while other guidance focuses the
activity further east towards central/north central areas during the
early afternoon Wednesday. Will need to monitor highs as guidance
may be trending too cool based on the coverage of precipitation and
cloud cover. I raised highs a few degrees for now as current
thinking sides with precip remaining mostly west of our area with
mostly sunny skies in the late afternoon and temps in the middle
80s.
Will likely see a break Wednesday evening before the cold front
arrives from the west Thursday afternoon, providing a better source
of lift for thunderstorms to develop. Lapse rates aloft remain weak
while ample instability and effective shear values peak at around 40
kts, lending to a few strong to severe storms, especially along and
south of the Interstate 70 corridor. Raised pops to likely south of
Interstate 70 for this period as all guidance points to the boundary
hanging up across southern KS with periods of thunderstorms
redeveloping in the afternoon hours on Friday. Mid level flow
becomes more westerly by this time, allowing for several vorticity
lobes to track from the southwest through Saturday evening.
Organized severe weather during this period is low, but cannot rule
out isolated storms being on the stronger side. On the north side of
the front, much of northeast Kansas remains on the cool side with
highs in the lower 80s and lows in the 60s. On Sunday and Monday,
while models are in large disagreement, there are trends in
shortwave ridging aloft bring a temporary end to precip chances for
the July fourth holiday. During the day, southerly flow returns
along with the heat and humidity as readings rise in to the lower
90s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1211 PM CDT TUE JUN 28 2016
VFR conditions are expected throughout the period. Winds will
decrease below 10 knots near dusk this evening. Thunderstorms will
be possible near dawn tomorrow morning as a complex of storms
moves south out of Nebraska. However, current thinking is storms
will stay west of the terminals. Future outlooks will continue to
analyze the potential.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barjenbruch
LONG TERM...Prieto
AVIATION...Baerg
Area Forecast Discussion
National Weather Service Dodge City KS
1201 PM CDT TUE JUN 28 2016
...Updated for Aviation...
.SHORT TERM...(Today and tonight)
Issued at 325 AM CDT Tue Jun 28 2016
The northwest flow pattern is underway, and along with it a
challenging forecast. At the time of this writing at 0800 UTC, there
were two small MCSs, one across far eastern Colorado and adjacent
far western KS with a second one across far north central KS. It
looks like a majority of the southwest KS region will avoid both of
these MCSs as they track almost due south. The exception will be the
western six counties were some rainfall of around a quarter inch can
be expected with some locally higher amounts through the mid-morning
hours before the MCS weakens. Some of the hourly HRRR runs want to
merge the two MCSs, so that will have to be watched later in the
morning, but right now that doesn`t seem to be happening, so we will
be keeping POPs fairly low with the exception of far southwest and
west central KS.
It is unclear exactly how convection will evolve late this afternoon
through tonight. We could see a repeat of yesterday, except starting
off a bit farther north in Nebraska. A mature MCS never really
materialized last night like was forecast, however that does not
mean that one large, coherent, long-lived MCS won`t happen
tonight. Signals are certainly there in both the high resolution
convective allowing models and lower resolution models. The NAM12
is particularly bullish, showing a significant QPF signal rolling
SSE from western Nebraska into southwest KS by 12z Wednesday. Both
the NCEP WRF-ARW and WRF-NMMB show something coherent rolling
across the same generally area before decaying around or shortly
after 09z Wednesday. In the official forecast, we will have 40-50
POPs going mainly east and north of a Dighton-Dodge-Greensburg-
Pratt line with greatest confidence and QPF forecast values up
along the I-70 corridor.
.LONG TERM...(Wednesday through Monday)
Issued at 325 AM CDT Tue Jun 28 2016
The active northwest flow pattern will continue through the end of
the week. A couple of things that will probably act to enhance
precipitation coverage and intensity later in the week will be 1) a
fairly decent surface front which will slow down and perhaps become
quasi-stationary across southern Kansas and 2) some minor mid level
perturbations/enhanced mid level moisture rotating around weak
ridging, thanks to abundance of mountain convection across the
southern Rockies. POPs in the Long Term will be highest Thursday
Night through Saturday Night with 12-hr POPs every period in the 40-
60 percent territory somewhere across our forecast area from west
central KS through south central KS. It still looks as though some
areas will see potentially excessive rainfall once the polar front
gets down here, given all the moisture that will be around and the
generally weak mid-upper level flow leading to slow-moving
convection.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1156 AM CDT Tue Jun 28 2016
Light east to southeasterly upslope will prevail with VFR
conditions. A complex of thunderstorms is then forecast to drop
south to southeastward across much of south central Kansas late
tonight and towards morning. The best guess for timing is at KHYS
around 08-11Z and 09-12z at KGCK and KDDC. Strong outflow winds
will be the main threat along with heavy rainfall and frequent
lightning.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 88 67 90 66 / 20 40 20 30
GCK 89 66 91 66 / 20 30 20 20
EHA 90 67 94 66 / 40 20 20 30
LBL 91 67 94 67 / 30 20 20 30
HYS 87 66 86 65 / 20 50 40 40
P28 91 68 90 69 / 20 30 30 40
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Umscheid
AVIATION...Kruse