Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/03/16
Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
522 PM AKDT SAT JUL 2 2016
.ANALYSIS AND UPPER LEVELS...
There is an upper level low in the southwest Yukon with a trough
"arm" extending westward across southern Alaska, and another "arm"
stretching northwest into east central Alaska. There is an upper
level low over the western Aleutians with a weak front extending
across the southern Bering Sea to the Alaska Peninsula. A weak
upper level ridge is in between these two lows, approximately
situated along the southwest Alaska coast. There is plenty of
moisture over most of southern Alaska. Considerable shower
activity is over inland southwest Alaska associated with the
westerly "arm" of the Yukon low. Lesser shower coverage is over
south central Alaska, mainly over the inland mountains.
&&
.MODEL DISCUSSION...
The numerical models are in reasonable agreement through the
short term portion of the forecast (Monday afternoon). There are
some differences in small scale features, and in a weak flow
pattern this can lead to forecast challenges. There is also a
subtle pattern change Sunday through Monday as the flow becomes
more southwesterly aloft. For these reasons, the forecast
confidence is a little below normal.
&&
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2...Sat and Sun)...
The Southcentral region will be under a showery weather regime as
an upper level shortwave move through the region. The best chance
for isolated thunderstorms will occur along the Alaska Range, and
the Talkeetnas. The thermal trough is north of the Alaska Range
and combined with diurnal heating should kick off evening
thunderstorms. This synoptic feature combined with a northeasterly
storm motion will have some of these thunderstorms track across
the Alaska Range into the Susitna Valley, Talkeetnas and the
Copper River Basin this evening. This same scenario for isolated
thunderstorms will occur Sunday afternoon/evening hours through
the aforementioned regions. Meanwhile, the Eastern Kenai will
have a shortwave moving through Sunday afternoon. The GFS20 model
was picking up a weak surface low developing over the Kenai
Mountains during the same time as the upper level shortwave.
Therefore, look for numerous showers along the Eastern Kenai for
Sunday afternoon/evening. This upper levels are showing
southwesterly flow, and will stream moisture into the Anchorage
Bowl. Look for the heaviest showers to occur over the mountains as
were heading in Sunday time-frame.
&&
.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
An upper low stalled over the Kuskokwim Valley continues to rotate
rain and showers over these areas. isolated thunderstorms will
also be possible this evening, but this activity should wane to
showers overnight with loss of heating. This pressure gradient
will also favor onshore flow along the coasts, especially across
the Bristol Bay region. It seems stratus is more widespread than
fog, but some fog patches as the marine air mass continues to
filter in is not out of the question.
Sunday, shower activity will remain over the same areas but
diminish in coverage and intensity as the low weakens. Southwest
flow increases on Monday, which will spread more clouds and
moisture inland, along with the possibility of isolated inland
thunderstorms.
&&
.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
Weak cyclonic flow over the Bering will support sporadic rain over
the region along with fog and stratus. A trough dropping in from
Eastern Siberia will support more extensive light periods of rain
and a continued southwest flow pattern.
&&
.LONG TERM FORECAST (Days 3 through 7)...
For the Independence Day holiday, a strong upper level trough over
the Central Bering will dig southeastward across the Eastern
Bering and into the southwest coast of Alaska by Wednesday. Weak
ridging aloft, east of the aforementioned upper trough, will move
in over the gulf Monday, which will quickly be replaced with an
upper low tracking in from the west by Wednesday. At the surface,
weak low pressure over the Bering will keep persistent onshore
flow over the Southwest Mainland, causing more wet and foggy
conditions over the area through the middle of next week. Meanwhile
over the Gulf and Southcentral Alaska, a weak southwesterly flow
pattern will set up over the area as a series of weak features
work their way over the area through the middle of next week. this
should keep mostly cloudy and showery conditions over much of the
area through midweek.
From mid-week into next weekend, forecast confidence remains lower
as the models continue to struggle with the timing and placement
of the above mentioned upper low/trough tracking through the
Southwest Mainland and into the Gulf of Alaska by the end of the
week. The models are also struggling with the timing and strength
of the ridging that builds in behind the low. The ECMWF was the
model of choice in this scenario showing slightly better
consistency and being the initial model to pick up on this
pattern, as well as being a good middle ground between the slower
Canadian solution and faster GFS solution.
&&
.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.
&&
$$
SYNOPSIS AND MODEL DISCUSSION...BL
SOUTHCENTRAL ALASKA...PD
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...JA
LONG TERM...TP
[top]
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
243 PM AKDT SAT JUL 2 2016
.SHORT TERM...A low pressure system is passing over Haida Gwaii
this afternoon and looks pretty impressive on satellite imagery.
The southern zones including Ketchikan and Hydaburg have had
moderate rainfall for most of the day. Strongest winds have been
limited to near the low center, but Annette Island has had gusts
around 25mph. The low will weaken as it progresses east into
Canada tonight. As this happens rain will become more showery and
largely move out of the area through the evening. Winds will
become more NWLY with the low to the SE and ease overnight.
Across the norther inner channels precip has already transitioned
to isolated showers with breaks of sunshine. Expect more breaks
this evening as surface high pressure starts to build over the
eastern gulf and the rest of the showers clear away. Exception to
this will be Yakutat where a mid/upper level low and bands of
vorticity will linger to the north through tomorrow afternoon.
This will keep at least scattered showers in the forecast there.
Some of the showers assoc with that upper level feature may spread
over the rest of the north/central panhandle through Sunday
afternoon, so have gone with isolated/scattered showers. Despite
this there should be sunny breaks tomorrow, so nudge high
temperatures up slightly.
Used a blend of the GFS22 and Canadian Regional models for updates
today. Forecast confidence is average.
.LONG TERM...Quasi-zonal midlevel flow is forecast to occur over
the gulf through midweek. An upper low then digs south of the
panhandle on Friday. Though rain will be possible during the long
term period, overall probabilities will generally be low, and
amounts will be light. Bigger weather story will be the potential
for a late week warm-up, as the system skirting south of the
region on Friday induces northerly low-level flow that aids in
downslope warming. Trended temperatures upward during the later
half of the week as a result.
No major changes were made to the previous forecast. Updated
pressure grids past day 4 with 12Z WPC. Remainder of the grids
were modified with an ensemble blend of model guidance, where
necessary.
&&
.AJK Watches/Warnings/Advisories...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ012-036-041.
Small Craft Advisory due to Seas for PKZ042.
&&
$$
Ferrin/Garner
Visit us at http://www.weather.gov/Juneau
[top]
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
108 PM AKDT SAT JUL 2 2016
.DISCUSSION...
MODELS...Similar solutions in the short term with very little
spread. There is some disagreement on the location of the low
aloft over the southeast interior on Monday that may effect
convective activity. 02/12Z runs initialized well against the
02/18Z surface analysis. GFS and ECMWF spreading the
precipitation far and wide, so will lean toward the NAM solution
for the short term. They all have different ideas on where the
heaviest precipitation will fall over the next couple days, so
again will go with the NAM solution.
ALOFT...At 500 HPA...A shortwave swinging around a 524 dam low in
the high arctic will lie over the dateline this afternoon. A 542
dam low will develop over Wrangel Island tonight in the base of
the trough, then move south over the Gulf of Anadyr by Monday
morning at 547 dam as the trough expands south over the central
Bering Sea. As the low break off the trough it will move southeast
over the Pribilof Islands Tuesday afternoon, then over Bristol Bay
by Wednesday morning, and over the Gulf of Alaska by Thursday
morning. Weak ridging over the Brooks Range will persist, but be
pushed east as the trough digs south, then moves north over the
arctic as weak troughing develops over the interior on Monday. A
554 dam low over Yakutat will wobble around a bit through the
weekend, then move north over the AlCan border Monday to MacKenzie
Bay by Tuesday morning. Ridging will build north over the eastern
Bering Sea on Wednesday. AT 850 HPA...A little cooler as the warm
ridge that has been over the state continues to erode and move to
the northeast. Zero isotherm remains north of the arctic coast
this week.
SURFACE...Pretty benign pattern over mainland Alaska. A broad
area of low pressure dominates with a thermal trough over the
central and eastern interior, and the upper Tanana Valley. Not
expecting much change in the pattern except to see the trough move
north a bit to the upper Yukon flats and south slopes of the
Brooks range by Monday, then it drifts back to the south. Weak
ridging will persist over the Gulf of Alaska and ridging will
build east of the arctic coast today and persist over the coast
and near shore waters through Tuesday.
ARCTIC COAST AND BROOKS RANGE...A little bit of stratus around
Barrow and Atqasuk but just a small band that appears to be
dissipating. Should be partly cloudy this evening, then look for
some stratus to develop over the coastal areas tonight with areas
of fog. A cold front approaches the northwest coast, but it should
stay offshore and dissipate or slide north of the coast. No
significant winds expected in the short term, but they could get
gusty from Barrow west as the front move near the area. Not much
change in temperatures the next few days. A few showers in the
eastern Brooks range the next couple days.
WEST COAST AND WESTERN INTERIOR...Quiet along the coastal areas. A
few patches of stratus may disrupt things, but should be pretty
nice most of the time. Inland is a different story as isolated to
scattered thunderstorms and showers will prevail for most areas
through mid week. Highest concentration of thunderstorms and
showers will be south of Huslia. Some patchy morning fog will
also present some issues. Winds in most location will be light
and variable. Temperatures a degree or two cooler the next few
days.
CENTRAL AND EASTERN INTERIOR...Showers will prevail with some
isolated to scattered thunderstorms in the afternoons and evenings
through mid week. Rainfall amounts will vary greatly, but the
highest amounts appear to be in the eastern Alaska range at this
time. No significant winds. Temperatures a couple degrees cooler.
&&
.FIRE WEATHER...Unsettled wet and cool pattern will persist
across the southern and eastern Interior with afternoon relative
humidities remaining above 40 percent. Relatively drier conditions
elsewhere across Northern Alaska will give way to the cool...wet
unsettled pattern and increased afternoon relative humidities
Monday as an longwave trough moves over the Bering Sea and West
Coast.
Isolated thunderstorms are possible over Interior from Galena to
McGrath and east as well as the southeastern Brooks Range over the
next few days. Instability will increase Sunday afternoon and
evening to where scattered thunderstorms are expected to develop
over an area from Lake Minchumina to Tanana and east including the
Yukon Flats. There is the potential for scattered thunderstorms on
Monday over the southeastern Interior, Yukon Flats, and
southeastern Brooks Range.
&&
.HYDROLOGY...Quite a few locations showing rises of 1 to 3 feet
today, but all the gaged rivers are within banks. Another round of
heavy rain possible in the eastern Alaska range with a chance it
could move over the central Alaska range. Will be monitoring the
area rainfall and gages in case further action needs to be taken.
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory for PKZ210.
&&
$$
SDB JUL 16
Southeast Alaska Forecast Discussion...Corrected
National Weather Service Juneau AK
608 AM AKDT SAT JUL 2 2016
.SHORT TERM...The flood warning for the Mendenhall Lake and River
has been cancelled early this morning. See the hydrology section
below and the flood warning cancellation statement for additional
information.
Main weather feature over the next 24 hours will be a compact low
pressure system tracking northeast across the northern portion of
Haida Gwaii around midday before weakening and moving into British
Columbia late tonight. This system is located in the left exit
region of a 100 kt upper level jet which will aid in deepening it
to around 1000 mb as it approaches Haida Gwaii. It rapidly loses
jet support thereafter and will quickly weaken as a result. Aside
from the far southern panhandle, the remainder of Southeast Alaska
will transition to a weak flow regime.
The effects of the compact low will be twofold. It will bring a
period of enhanced lift and moderate to occasionally heavy rain
through this afternoon for the southern panhandle. Additionally, a
strong southeasterly low level jet with 925 mb winds of around 50
kt will increase winds over the far southern panhandle. However,
with the track of the system the strongest winds are expected to
remain over Dixon Entrance and south of the panhandle.
For the northern panhandle, this low will act to shift flow to the
east-southeast leading to diminishing rainfall chances through the
day. Some peaks of blue sky and sun will even be possible across
the northern half this afternoon and evening. Lingering gusty
winds this morning associated with a weakening low near Cape
Fairweather will also diminish through the morning with a weak
pressure gradient and generally light winds in place later this
afternoon and into tonight.
Used the 06z NAM/GFS for updates to the short term forecast based
upon good agreement on track and strength of low pressure system
moving into the far southeast gulf.
.LONG TERM...The low with the upper level support for the
Saturday low over the Dixon Entrance region moves into British
Columbia Sunday and as a result the main rain band will be pulling
inland across the southern panhandle as well. A weak surface ridge
over the eastern gulf will be displaced eastward across the
panhandle. Meanwhile, a weak negatively tilted trough associated
with a small weak low near Middleton Island Saturday night will
stall along the coast of Southeast Alaska. Another weak low will
move east across the western Gulf of Alaska, and a more organized
low for mid next week.
Aloft the main pattern is general westerly flow across the north
Pacific and Gulf of Alaska. This has been the trend for the
end of the week into the first half of next week so minimal
changes were made. Kept the mostly cloudy and low chance level
POP`s for rain. Wind should be 20 kt or less for the next several
days. Confidence will be average through the mid to later parts of
the forecast.
The minor adjustments made to the forecast package was based on
a NAM/GFS blend while the later periods were based on the WPC
guidance.
&&
.HYDROLOGY...Suicide Basin emptied on Friday afternoon with
Mendenhall Lake cresting at 11.99 feet on Friday evening. This
broke the previous record high crest of 11.85 feet in 2014. Water
levels have receded rapidly overnight and will continue to do so
through the weekend.
&&
.AJK Watches/Warnings/Advisories...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ036-041.
Small Craft Advisory due to Seas for PKZ042-043.
&&
$$
TPS/Bezenek
Visit us at http://www.weather.gov/Juneau
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
536 AM AKDT SAT JUL 2 2016
.SHORT TERM...The flood warning for the Mendenhall Lake and River
has been cancelled early this morning. See the hydrology section
below and the flood warning cancellation statement for additional
information.
Main weather feature over the next 24 hours will be a compact low
pressure system tracking northeast across the northern portion of
Haida Gwaii around midday before weakening and moving into British
Columbia late tonight. This system is located in the left exit
region of a 100 kt upper level jet which will aid in deepening it
to around 1000 mb as it approaches Haida Gwaii. It rapidly loses
jet support thereafter and will quickly weaken as a result. Aside
from the far southern panhandle, the remainder of Southeast Alaska
will transition to a weak flow regime.
The effects of the compact low will be twofold. It will bring a
period of enhanced lift and moderate to occasionally heavy rain
through this afternoon for the southern panhandle. Additionally, a
strong southeasterly low level jet with 925 mb winds of around 50
kt will increase winds over the far southern panhandle. However,
with the track of the system the strongest winds are expected to
remain over Dixon Entrance and south of the panhandle.
For the northern panhandle, this low will act to shift flow to the
east-southeast leading to diminishing rainfall chances through the
day. Some peaks of blue sky and sun will even be possible across
the northern half this afternoon and evening. Lingering gusty
winds this morning associated with a weakening low near Cape
Fairweather will also diminish through the morning with a weak
pressure gradient and generally light winds in place later this
afternoon and into tonight.
Used the 06z NAM/GFS for updates to the short term forecast based
upon good agreement on track and strength of low pressure system
moving into the far southeast gulf.
.LONG TERM...The low with the upper level support for the
Saturday low over the Dixon Entrance region moves into British
Columbia Sunday and as a result the main rain band will be pulling
inland across the southern panhandle as well. A weak surface ridge
over the eastern gulf will be displaced eastward across the
panhandle. Meanwhile, a weak negatively tilted trough associated
with a small weak low near Middleton Island Saturday night will
stall along the coast of Southeast Alaska. Another weak low will
move east across the western Gulf of Alaska, and more organized
low for mid next week.
Aloft the main pattern is general westerly flow pattern across the
north Pacific and Gulf of Alaska. This has been the trend for the
end of the week into the first half of next week so minimal
changes were made. Kept the mostly cloudy and Low chance level
PoP`s for rain. Wind should be 20 kt or less for the next several
days. Confidence will be average through the mid to later parts of
the forecast.
the Minor adjustments made too the forecast package was based on
a NAM/GFS blend while the later periods were based on the WPC
guidance.
&&
.HYDROLOGY...Suicide Basin emptied on Friday afternoon with
Mendenhall Lake cresting at 11.99 feet on Friday evening. This
broke the previous record high crest of 11.85 feet in 2014. Water
levels have receded rapidly overnight and will continue to do so
through the weekend.
&&
.AJK Watches/Warnings/Advisories...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ036-041.
Small Craft Advisory due to Seas for PKZ042-043.
&&
$$
TPS/Bezenek
Visit us at http://www.weather.gov/Juneau
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
536 AM AKDT SAT JUL 2 2016
.SHORT TERM...The flood warning for the Mendenhall Lake and River
has been cancelled early this morning. See the hydrology section
below and the flood warning cancellation statement for additional
information.
Main weather feature over the next 24 hours will be a compact low
pressure system tracking northeast across the northern portion of
Haida Gwaii around midday before weakening and moving into British
Columbia late tonight. This system is located in the left exit
region of a 100 kt upper level jet which will aid in deepening it
to around 1000 mb as it approaches Haida Gwaii. It rapidly loses
jet support thereafter and will quickly weaken as a result. Aside
from the far southern panhandle, the remainder of Southeast Alaska
will transition to a weak flow regime.
The effects of the compact low will be twofold. It will bring a
period of enhanced lift and moderate to occasionally heavy rain
through this afternoon for the southern panhandle. Additionally, a
strong southeasterly low level jet with 925 mb winds of around 50
kt will increase winds over the far southern panhandle. However,
with the track of the system the strongest winds are expected to
remain over Dixon Entrance and south of the panhandle.
For the northern panhandle, this low will act to shift flow to the
east-southeast leading to diminishing rainfall chances through the
day. Some peaks of blue sky and sun will even be possible across
the northern half this afternoon and evening. Lingering gusty
winds this morning associated with a weakening low near Cape
Fairweather will also diminish through the morning with a weak
pressure gradient and generally light winds in place later this
afternoon and into tonight.
Used the 06z NAM/GFS for updates to the short term forecast based
upon good agreement on track and strength of low pressure system
moving into the far southeast gulf.
.LONG TERM...The low with the upper level support for the
Saturday low over the Dixon Entrance region moves into British
Columbia Sunday and as a result the main rain band will be pulling
inland across the southern panhandle as well. A weak surface ridge
over the eastern gulf will be displaced eastward across the
panhandle. Meanwhile, a weak negatively tilted trough associated
with a small weak low near Middleton Island Saturday night will
stall along the coast of Southeast Alaska. Another weak low will
move east across the western Gulf of Alaska, and more organized
low for mid next week.
Aloft the main pattern is general westerly flow pattern across the
north Pacific and Gulf of Alaska. This has been the trend for the
end of the week into the first half of next week so minimal
changes were made. Kept the mostly cloudy and Low chance level
PoP`s for rain. Wind should be 20 kt or less for the next several
days. Confidence will be average through the mid to later parts of
the forecast.
the Minor adjustments made too the forecast package was based on
a NAM/GFS blend while the later periods were based on the WPC
guidance.
&&
.HYDROLOGY...Suicide Basin emptied on Friday afternoon with
Mendenhall Lake cresting at 11.99 feet on Friday evening. This
broke the previous record high crest of 11.85 feet in 2014. Water
levels have receded rapidly overnight and will continue to do so
through the weekend.
&&
.AJK Watches/Warnings/Advisories...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ036-041.
Small Craft Advisory due to Seas for PKZ042-043.
&&
$$
TPS/Bezenek
Visit us at http://www.weather.gov/Juneau
Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
500 AM AKDT SAT JUL 2 2016
.ANALYSIS AND UPPER LEVELS...
Upper level lows remain over the western Bering and the
southeastern Gulf of Ak this morning, with a weak ridge along the
west coast of the mainland. At the surface, a low is near Amchitka
and a second is headed to Haida Gwaii. A weak ridge of high
pressure is draped from the northwest Bering to Cold Bay, and a
decaying front parallels the ridge slightly to its west. the
thermal trough/theta-e ridge remains along the northern and
western flanks of the Alaska and Aleutian ranges.
&&
.MODEL DISCUSSION...
Models are in general agreement that the Gulf upper and surface
low complex are headed into southeast Ak today. The low will
elongate and split with the main portion headed into British
Columbia, and a smaller low drifting just east of the Alcan until
dissipating early next week. An associated extremely weak surface
low will drift in the northern Gulf through the period. As the
upper low exits to the southeast it will send a few waves through
the thermal trough today and Sun before the pattern shifts and the
easterly waves come to an end. This will be caused by an upper
trough digging south through the Bering Sun and Mon.
In the west, the decaying front will be stretched as the Aleutian
low weakens into a broad trough. The moisture rich remnants of
the system will then interact with the diving trough later on Mon.
The forecasts utilized some GFS and Nam to capture wave details.
&&
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2...Sat and Sun)...
The strong disturbance bringing moderate to heavy rains to parts
of Southwest Alaska will pivot in place over lower Cook Inlet
later today and then significantly weaken. The associated rains
with this system will impact Kodiak Island this morning, and then
diminish in intensity over the Barren Islands, just clipping the
southern Kachemak Bay region. Meanwhile...the rest of the area
will remain in very light flow with generally moist and marginally
unstable conditions. With all the recent rainfall...many places
could see some patchy fog or low stratus develop overnight, but
this should dissipate relatively quickly on Saturday as some sun
breaks through. Showers should develop along the mountains in the
afternoon, but with weak steering flow, we don`t expect many of
them to make it into valleys. The best instability remains farther
north over the Alaska Range and parts of the Talkeetna Mountains
as well as the northern half of the Copper River Basin, so
isolated thunderstorms are expected in these locations.
Increasing southwesterly flow and an approaching upper
disturbance Sunday into Sunday night will mean a slow stabilizing
trend as we approach the Independence Day holiday Monday. Expect
more robust shower activity over the Kenai Range Sunday afternoon
and evening, and as 850-mb and 700-mb southwesterly flow
increases, we cannot at this time rule out at least some chance of
light rain pushing north off of the mountains into parts of
Anchorage and the Matanuska Valley late Sunday night into early
Monday.
&&
.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
The cloudy rainy pattern over the mainland will continue the next
two days with decreasing coverage each day. Steady rain will shift
from the Kuskokwim Valley southward into Greater Bristol Bay
during the afternoon. The Kuskokwim Delta will be right on the
edge of the disturbance over the Eastern Mainland, and should stay
mostly shower-free save for areas south and east of Bethel in the
afternoon/evening hours. Overnight into Sunday most of the rain
will be confined to the higher elevations of the Kuskokwim Valley.
The flow pattern changes on Monday in response to a developing
trough in the Western Bering Sea, which will result in continued
cloudiness and a small chance for light rain.
&&
.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
The upper level low pressure system over the western Bering
continues to weaken. A disturbance within the flow will weaken
over the Eastern Aleutians and Alaska Peninsula today as light
rain tapers off to sprinkles. The large scale trough stays in the
area continuing a small chance for light rain before a stronger
disturbance drops into the northwestern Bering late Sunday night.
&&
.LONG TERM FORECAST (Days 3 through 7)...
For the Independence Day holiday, a strong upper level trough will
dig southward across the eastern Bering. Ridging will build east
of it across the Gulf. However, the models are in disagreement
with how quickly the ridge builds, and where the trough axis sets
up over the Bering. Currently, the models agree enough for the
4th of July to suggest a return to southwesterly winds in the
upper levels. Since the disturbances depicted in the models all
remain weak, the weather looks similar to Sunday at this point for
much of mainland Alaska.
Active weather should persist for much of southern Alaska into
midweek as the trough over the Bering moves into mainland Alaska.
However, the model differences and associated forecast
uncertainty only compound with time concerning how quickly and in
what form (open trough or cutoff low), the troughing moves east.
&&
.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.
&&
$$
SYNOPSIS AND MODEL DISCUSSION...DS
SOUTHCENTRAL ALASKA...CC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...ML
LONG TERM...TP/DS
Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
500 AM AKDT SAT JUL 2 2016
.ANALYSIS AND UPPER LEVELS...
Upper level lows remain over the western Bering and the
southeastern Gulf of Ak this morning, with a weak ridge along the
west coast of the mainland. At the surface, a low is near Amchitka
and a second is headed to Haida Gwaii. A weak ridge of high
pressure is draped from the northwest Bering to Cold Bay, and a
decaying front parallels the ridge slightly to its west. the
thermal trough/theta-e ridge remains along the northern and
western flanks of the Alaska and Aleutian ranges.
&&
.MODEL DISCUSSION...
Models are in general agreement that the Gulf upper and surface
low complex are headed into southeast Ak today. The low will
elongate and split with the main portion headed into British
Columbia, and a smaller low drifting just east of the Alcan until
dissipating early next week. An associated extremely weak surface
low will drift in the northern Gulf through the period. As the
upper low exits to the southeast it will send a few waves through
the thermal trough today and Sun before the pattern shifts and the
easterly waves come to an end. This will be caused by an upper
trough digging south through the Bering Sun and Mon.
In the west, the decaying front will be stretched as the Aleutian
low weakens into a broad trough. The moisture rich remnants of
the system will then interact with the diving trough later on Mon.
The forecasts utilized some GFS and Nam to capture wave details.
&&
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2...Sat and Sun)...
The strong disturbance bringing moderate to heavy rains to parts
of Southwest Alaska will pivot in place over lower Cook Inlet
later today and then significantly weaken. The associated rains
with this system will impact Kodiak Island this morning, and then
diminish in intensity over the Barren Islands, just clipping the
southern Kachemak Bay region. Meanwhile...the rest of the area
will remain in very light flow with generally moist and marginally
unstable conditions. With all the recent rainfall...many places
could see some patchy fog or low stratus develop overnight, but
this should dissipate relatively quickly on Saturday as some sun
breaks through. Showers should develop along the mountains in the
afternoon, but with weak steering flow, we don`t expect many of
them to make it into valleys. The best instability remains farther
north over the Alaska Range and parts of the Talkeetna Mountains
as well as the northern half of the Copper River Basin, so
isolated thunderstorms are expected in these locations.
Increasing southwesterly flow and an approaching upper
disturbance Sunday into Sunday night will mean a slow stabilizing
trend as we approach the Independence Day holiday Monday. Expect
more robust shower activity over the Kenai Range Sunday afternoon
and evening, and as 850-mb and 700-mb southwesterly flow
increases, we cannot at this time rule out at least some chance of
light rain pushing north off of the mountains into parts of
Anchorage and the Matanuska Valley late Sunday night into early
Monday.
&&
.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
The cloudy rainy pattern over the mainland will continue the next
two days with decreasing coverage each day. Steady rain will shift
from the Kuskokwim Valley southward into Greater Bristol Bay
during the afternoon. The Kuskokwim Delta will be right on the
edge of the disturbance over the Eastern Mainland, and should stay
mostly shower-free save for areas south and east of Bethel in the
afternoon/evening hours. Overnight into Sunday most of the rain
will be confined to the higher elevations of the Kuskokwim Valley.
The flow pattern changes on Monday in response to a developing
trough in the Western Bering Sea, which will result in continued
cloudiness and a small chance for light rain.
&&
.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
The upper level low pressure system over the western Bering
continues to weaken. A disturbance within the flow will weaken
over the Eastern Aleutians and Alaska Peninsula today as light
rain tapers off to sprinkles. The large scale trough stays in the
area continuing a small chance for light rain before a stronger
disturbance drops into the northwestern Bering late Sunday night.
&&
.LONG TERM FORECAST (Days 3 through 7)...
For the Independence Day holiday, a strong upper level trough will
dig southward across the eastern Bering. Ridging will build east
of it across the Gulf. However, the models are in disagreement
with how quickly the ridge builds, and where the trough axis sets
up over the Bering. Currently, the models agree enough for the
4th of July to suggest a return to southwesterly winds in the
upper levels. Since the disturbances depicted in the models all
remain weak, the weather looks similar to Sunday at this point for
much of mainland Alaska.
Active weather should persist for much of southern Alaska into
midweek as the trough over the Bering moves into mainland Alaska.
However, the model differences and associated forecast
uncertainty only compound with time concerning how quickly and in
what form (open trough or cutoff low), the troughing moves east.
&&
.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.
&&
$$
SYNOPSIS AND MODEL DISCUSSION...DS
SOUTHCENTRAL ALASKA...CC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...ML
LONG TERM...TP/DS
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
419 AM AKDT SAT JUL 2 2016
.DISCUSSION...
UPPER AIR...
A weak ridge currently extends from St Lawrence Island to the
eastern Beaufort Sea then links up to a much stronger ridge over
northwest Canada. The Alaskan portion of the ridge will gradually
weaken through Saturday night, with the main high pressure aloft
remaining over northwestern Canada by Sunday afternoon. A more
organized mainly southerly flow pattern aloft will become
established over the northern Alaska Mainland by Monday
afternoon. A weak upper low will develop over the extreme southern
Yukon Territory this afternoon, remain nearly stationary through
Sunday night, then weakening into a trough lifting northward
across the eastern Alaska interior Monday through Tuesday.
A weak short wave trough along the Alcan border south of the
Brooks Range will move to the southeast interior by this
afternoon, weakening into a weak upper low near the middle Tanana
Valley by this evening. This feature will weaken into a weak
trough over Denali by Sunday afternoon, then dissipate Sunday
night.
A strong short wave trough extending from 80N/180W to the New
Siberian Islands will swing eastward around a strong upper low
over the north polar region. By late tonight the short wave will
extend from 80N/160E to Wrangel Island and southward into the
Russian mainland. The trough will then remain stationary through
Sunday night while deepening into an elongated low extending from
Wrangel Island to south of the Gulf of Anadyr.
SURFACE...
A 1002 mb low centered about 100 miles east of Northway will
weaken to a 1002 mb low centered 100 miles east of Fort Yukon
by late tonight. A 1002 mb low will develop 50 miles west of
Bettles this afternoon with a weak thermal trough extending
eastward into the upper Yukon Valley. This thermal trough will
gradually intensify through Sunday and weaken to the northern
Brooks Range by Monday afternoon, with a main 1006 mb thermal
low over the central Brooks Range. A weak high pressure ridge
will expand eastward across the Beaufort Sea tonight, with a
1014 mb high forming 300 miles north of Deadhorse by Sunday
evening. The high will build to 1020 mb by Monday evening as
it moves northeastward to Prince Patrick Island in the Canadian
archipelago. A 1020 mb high centered west of the New Siberian
Islands will weaken to a 1015 mb high centered near Wrangel
Island by Monday morning.
INTERIOR...
Today and this evening..Showers and isolated thunderstorms are
expected over most areas. Convective activity could be enhanced by
a weak short wave trough along the Alcan border. The greatest
instability this afternoon and evening will be over the western
interior. Showers likely continuing into the late night hours.
Sunday and Sunday evening...Showers and isolated thunderstorms
continuing over the central and eastern interior. Scattered
showers and isolated thunderstorms also possible in the upper
Kuskokwim Valley. Showers likely continuing into the late
night hours.
Monday and Monday evening...Showers and isolated thunderstorms
continuing over almost all of the central and eastern interior,
and in extreme southern parts of the western interior. The most
instability is expected to be over the northeastern interior, GFS
indicating areas of 800-1000 J/kg surface CAPE with surface lifted
index as low as -3. There is potential for the thunderstorm
activity to be scattered in parts of the northeast interior, but
at this time we will stay with isolated activity. Future model
runs will need to be monitored. A weakening short wave trough
moving northward across the eastern interior could enhance
thunderstorm activity as well as triggering extensive showers.
Showers likely continuing into the late night hours.
WEST COAST...
No significant weather expected through Monday. Patchy
coastal fog in some areas.
ARCTIC SLOPE AND BROOKS RANGE...
Warm temperatures continuing through Monday...especially in the
interior where high temperatures will reach 70 or higher in many
areas. Patchy fog possible along the coast during the late night
and early morning hours. Scattered rain showers over the
northeastern Brooks Range Sunday night and Monday, with isolated
thunderstorms Monday afternoon.
Coastal Hazard Potential Days 3 and 4...None.
&&
.FIRE WEATHER...
Minimum RH expected to be 40% or higher over most interior areas
today. Warmer temperatures over the northern and northeastern
interior Sunday and Monday. Minimum humidities are expected to be
lower, but still above 30-35 percent. Forecast CAPE and lifted
index numbers indicate the possibility of scattered thunderstorms
in parts of the northeastern interior Monday. We are going with
isolated thunderstorms on this mornings forecast package, but
forecast CAPE and lifted index on future model runs will need to
be monitored.
&&
.HYDROLOGY...
Given the high precipitable water values (1 to 1.2 inches) in
parts of the central and eastern interior through Tuesday, there
is potential for locally heavy showers which, if they occur in
mountainous terrain, could cause small stream flood issues. Rain
gage data will need to be closely monitored.
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
RF JUL 16
Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
441 PM AKDT FRI JUL 1 2016
.ANALYSIS AND UPPER LEVELS...
The upper level low remains over the Gulf of Alaska, but is
beginning to show signs of moving east. The strong short-wave
system on the northwest side of the low that provided last nights
rainfall to south central Alaska is now in southwest Alaska. There
is an upper level low over the southwest Bering Sea as well as the
western and central Aleutians. This low has stalled and is
continuing to weaken. A weather front associated with this low
stretches from about Nikolski northwestward across the Bering
Sea. A ridge of high pressure separates these two low, with the
"col" over the far eastern Bering.
&&
.MODEL DISCUSSION...
The numerical models are in reasonable agreement on the over-all
pattern. There continue to be some differences in the timing,
location, and strength of various short-waves surrounding the
Gulf low. There are also some minor differences in the handling
of precipitation, especially in regards to convection. Therefore
the forecast confidence is slightly below normal.
&&
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2...Sat and Sun)...
Afternoon mountain showers and diurnal sea breezes will be the
story for the weekend. The easterly wave that brought a third to
an inch and half of rain across Southcentral has cleared through
most of the area. The Alaska Range has slowed its westward
progress keeping some rain falling over Kachemak Bay. It will
pivot through this corridor on Sat bringing rain to parts of
Kodiak Island later tonight through the Sat morning hours.
Meanwhile...the rest of the area will remain in very light flow
with generally moist and unstable conditions. With all the recent
rainfall...many places could see some patchy fog or low stratus
develop overnight. But this should dissipate relatively quickly on
Saturday as some sun breaks through. Showers should develop along
the mountains in the afternoon, but with weak steering flow, we
don`t expect many of them to make it into valleys. The best
instability remains farther north over the Alaska Range and parts
of the Talkeetna Mountains, so can`t rule out an isolated
thunderstorm developing on those higher peaks. Sun looks very
similar to Sat with minimal change to the pattern. The leftover
band of rain near Kodiak should move off into the Gulf making for
drying conditions there.
&&
.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
The Gulf low that has been relatively stationary the last couple
of days will finally push off to the east tonight. This will
change the easterly flow over the area to be more northerly which
will help to diminish showers over the area. The majority of the
rain remaining by the beginning of next week will be in the more
eastern parts of Southwest Alaska like the Alaska and Aleutian
Ranges.
Even though the main upper level low is departing there are still
more shortwaves moving through the area with the strongest one
coming through this evening. It will track south from the
Kuskokwim Valley towards Bristol Bay and will help to initiate
thunderstorms in the area. There will also be enough instability
over the Kuskokwim Valley for possible afternoon thunderstorms
Saturday and Sunday.
&&
.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
The broad area of low pressure over the Western Aleutians will
track slowly east over the weekend. It looks to bring light rain
to the Aleutians with some making it to the Pribilof Islands on
Saturday. By the beginning of next week the broad upper level low
will be absorbed into a broad trough extending across the Bering
from the north. This trough will keep light rain over the Bering
and Aleutians.
&&
.LONG TERM FORECAST (Days 3 through 7)...
The upper level pattern will begin to shift by the end of this
weekend to a more stable pattern, as the upper low shifts further
east and weak high pressure aloft builds in from the west. Thus,
with everything being weak, any precipitation that develops Sunday
over southern mainland Alaska will be mostly scattered and weak.
The persistence of a mid-level unstable layer over much of the
area will result in some diurnal showers mainly along the
mountains.
For the Independence Day holiday, a strong upper level trough will
dig southward across the eastern Bering. Ridging will build east
of it across the Gulf. However, the models are in disagreement
with how quickly the ridge builds, and where the trough axis sets
up over the Bering. Currently, the models agree enough for the
4th of July to suggest a return to southwesterly winds in the
upper levels. Since the disturbances depicted in the models all
remain weak, the weather looks similar to Sunday at this point for
much of mainland Alaska.
Active weather should persist for much of southern Alaska into
midweek as the trough over the Bering moves into mainland Alaska.
However, the model differences and associated forecast
uncertainty only compound with time concerning how quickly and in
what form (open trough or cutoff low), the troughing moves east.
&&
.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.
&&
$$
SYNOPSIS AND MODEL DISCUSSION...BL
SOUTHCENTRAL ALASKA...MO
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...DK
LONG TERM...TP
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
324 PM AKDT FRI JUL 1 2016
.SHORT TERM...A low just west of Sitka this afternoon continues to
track north along the outer coast. Visible and WV satellite
imagery is clearly depicting the circulation, but it is not nearly
as evident in IR imagery. Radar has been showing banding in the
returns, but the total system is slightly stronger than
originally expected and had produced 30 kts of wind in Clarence
Strait earlier today. Morning model runs still showing some
divergence on the low center. With the system so close to the
outer coast, minor differences in location, track, and intensity
can have significant impacts in the forecast. That said, opted for
the NAM for updates to pressure and winds today. Resulting changes
primarily affect the winds over the eastern gulf and coastal
locations north of Cape Decision. On the inside, result was to
increase winds speeds a bit, so the afternoon forecast features
small craft advisories for several of the inner channels. Clarence
Strait is expected to continue at high end small craft intensity
through the evening before relaxing. A low approaching the Dixon
Entrance from the southwest tomorrow will produce another round of
small craft winds out of the east tomorrow afternoon, but these
winds will be mostly over southern areas near the Dixon Entrance.
Small craft southerlies will get into the ocean entrances of
Chatham Strait and Sumner Strait early this evening but should
diminish to 15 kts or so by tomorrow morning. Also expect small
craft winds out of the east over eastern portions of Sumner and
southeasterlies to 25 kts along Frederick Sound south of Cape
Fanshaw. Later tonight, max winds on the inside will shift north
to include Stephens passage north of Taku inlet, the northern
portions of Chatham Strait, and much of Icy Strait. Finally,
easterly Small Craft winds to 30 kts from late this evening
through tomorrow afternoon are forecast for Cross Sound. Small
craft winds on the outside will progress from south to north as
well, ending late morning as the low weakens and fills vicinity
of Cape Fairweather.
POP forecast from last night still looks good, so no changes
there. Did update QPF using a blend of Canadian REG and NAMDNG.
Overall forecast confidence is average to below average due to
uncertainties in how inner channel winds will respond to the low
off the coast.
.LONG TERM...The low passing through Dixon Entrance Saturday night
will keep showers largely confined to the southern panhandle. An
upper level low shifts south Saturday night then looks to settle
over central BC Sunday. This will also help to clear away showers
initially over the north, but then once its in Canada may cause
clouds and some showers to move in from the east. For this reason
chance/slight chance of showers remain in the forecast over the
weekend. Weak ridging will develop over the gulf starting Monday,
or a better way to describe it, zonal onshore flow. This leads to
a chance of rain in the forecast, or at least a bit more cloud
cover. There are some indications that a marine layer could
develop over the gulf under the ridge, this will be monitored
over the next couple days. If an inversion develops or there is a
low cloud deck that would be of concern for Monday night
activities along the outer coast.
Adjusted temps up slightly through the extended forecast as both
base models and bias corrected models were warmer. Thinking that
sunny breaks in the clouds will allow for more seasonable highs
in the mid 60s.
Used an ensemble approach for updates today. Model agreement on
pressure was good through the mid range then diverged day 6, used
more WPC guidance for later periods. Model differences on the POP
forecast were still fairly high over the holiday, so still lower
confidence in that part of the forecast.
&&
.HYDROLOGY...Early afternoon indications are that Suicide Basin
may have emptied out. The lake, however, will continue to rise
through the evening, with a forecast crest of at or near 12 feet
later tonight. See the flood warning issued by NWS Juneau for
details and be careful and vigilant around flood waters.
&&
.AJK Watches/Warnings/Advisories...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ021-022-031>036-041>043.
&&
$$
Fritsch/Ferrin
Visit us at http://www.weather.gov/Juneau
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
324 PM AKDT FRI JUL 1 2016
.SHORT TERM...A low just west of Sitka this afternoon continues to
track north along the outer coast. Visible and WV satellite
imagery is clearly depicting the circulation, but it is not nearly
as evident in IR imagery. Radar has been showing banding in the
returns, but the total system is slightly stronger than
originally expected and had produced 30 kts of wind in Clarence
Strait earlier today. Morning model runs still showing some
divergence on the low center. With the system so close to the
outer coast, minor differences in location, track, and intensity
can have significant impacts in the forecast. That said, opted for
the NAM for updates to pressure and winds today. Resulting changes
primarily affect the winds over the eastern gulf and coastal
locations north of Cape Decision. On the inside, result was to
increase winds speeds a bit, so the afternoon forecast features
small craft advisories for several of the inner channels. Clarence
Strait is expected to continue at high end small craft intensity
through the evening before relaxing. A low approaching the Dixon
Entrance from the southwest tomorrow will produce another round of
small craft winds out of the east tomorrow afternoon, but these
winds will be mostly over southern areas near the Dixon Entrance.
Small craft southerlies will get into the ocean entrances of
Chatham Strait and Sumner Strait early this evening but should
diminish to 15 kts or so by tomorrow morning. Also expect small
craft winds out of the east over eastern portions of Sumner and
southeasterlies to 25 kts along Frederick Sound south of Cape
Fanshaw. Later tonight, max winds on the inside will shift north
to include Stephens passage north of Taku inlet, the northern
portions of Chatham Strait, and much of Icy Strait. Finally,
easterly Small Craft winds to 30 kts from late this evening
through tomorrow afternoon are forecast for Cross Sound. Small
craft winds on the outside will progress from south to north as
well, ending late morning as the low weakens and fills vicinity
of Cape Fairweather.
POP forecast from last night still looks good, so no changes
there. Did update QPF using a blend of Canadian REG and NAMDNG.
Overall forecast confidence is average to below average due to
uncertainties in how inner channel winds will respond to the low
off the coast.
.LONG TERM...The low passing through Dixon Entrance Saturday night
will keep showers largely confined to the southern panhandle. An
upper level low shifts south Saturday night then looks to settle
over central BC Sunday. This will also help to clear away showers
initially over the north, but then once its in Canada may cause
clouds and some showers to move in from the east. For this reason
chance/slight chance of showers remain in the forecast over the
weekend. Weak ridging will develop over the gulf starting Monday,
or a better way to describe it, zonal onshore flow. This leads to
a chance of rain in the forecast, or at least a bit more cloud
cover. There are some indications that a marine layer could
develop over the gulf under the ridge, this will be monitored
over the next couple days. If an inversion develops or there is a
low cloud deck that would be of concern for Monday night
activities along the outer coast.
Adjusted temps up slightly through the extended forecast as both
base models and bias corrected models were warmer. Thinking that
sunny breaks in the clouds will allow for more seasonable highs
in the mid 60s.
Used an ensemble approach for updates today. Model agreement on
pressure was good through the mid range then diverged day 6, used
more WPC guidance for later periods. Model differences on the POP
forecast were still fairly high over the holiday, so still lower
confidence in that part of the forecast.
&&
.HYDROLOGY...Early afternoon indications are that Suicide Basin
may have emptied out. The lake, however, will continue to rise
through the evening, with a forecast crest of at or near 12 feet
later tonight. See the flood warning issued by NWS Juneau for
details and be careful and vigilant around flood waters.
&&
.AJK Watches/Warnings/Advisories...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ021-022-031>036-041>043.
&&
$$
Fritsch/Ferrin
Visit us at http://www.weather.gov/Juneau
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
303 PM AKDT FRI JUL 1 2016
.SYNOPSIS...
Aloft...
A ridge stretching east to west across northern Alaska will
persist through the weekend then retreat east in NW Canada next
week as a trough develops over the Bering Sea. A low aloft in the
Gulf of Alaska will move over SE Alaska Sat and then move slowly
east. A series of short wave troughs rotating around this low will
move west across Interior Alaska bringing bands of showers and
isolated to scattered thunderstorms to the eastern and southern
Interior through the weekend.
A strong short wave that now lies from Denali to Livengood to Old
Crow will move to McGrath to Tanana to Arctic Village by 4am
Sat...and then weaken in place through Sun. There is a wide band
of showers NW of this trough that becomes scattered north of the
Yukon River. This dropped .10 to .25 inch of rain over the eastern
Interior south of Circle with up to .50 inch in the hills north of
Fox and east of Delta Junction. Expect this to drop another .50 to
1 inch over zones 221 225 and 227 through Sat with the heaviest
amounts in Denali Park. From .50-1.5 inch of rain has already
fallen in Denali Park so this will keep small stream and rivers
there high through the weekend and could still cause mud and rock
slides.
A second and weaker short wave trough near Old Crow will move to
Fort Yukon by 4am Sat...to Denali to Livengood by 4pm Sat...and
then slowly dissipate through Sun. This will cause scattered
showers and scattered PM thunderstorms in eastern zone 216
western 221 and 227 Sat and into Sun. The thunderstorms could
have small hail Sat.
A third short wave trough over the southern Yukon Territory will
move to the ALCAN Border by 4pm Sat and then weaken over the
eastern Interior through Sun. This will bring more widespread
showers to zones 224 226 Sat into Sun and keep scattered showers
and at least isolated thunderstorms going in the remainder of the
eastern Interior. There is the potential for hail again Sun and
this will need to be watched.
A fourth short wave is expected to move to the extreme SE interior
Sun night and Mon and could bring heavy rain...but this still has
a lot of uncertainty.
Surface...
An Arctic warm front from Barter Island to Deadhorse will move to
Barter Island north by 4am Sat then move north of the coast.
Expect fog to reform along this front tonight and then move
offshore Sat.
A 1022 mb high over the central Bering Sea will weaken slowly
through Sun.
An Arctic cold front in the western Chukchi Sea will move east to
Barrow to Cape Lisburne then west by 4pm Sat...to Deadhorse to a
1007 mb low near Point Hope by 4am Sun...and then quasi-
stationary. Fog and a chance of rain will accompany the front.
Westerly flow will increase south of the low center and should
return widespread fog to the southern Chukchi and north Bering
Seas and most of the West Coast of AK by Sat night.
&&
.DISCUSSION...
Models are similar on the large scale flow pattern and features
but differ some on timing and location of weak short wave troughs
moving west across the Interior. Since these weak short wave
troughs are the main force driving convection over the interior
the location is important. We favor the GFS locations of the short
waves and heavy rain through Sat night Sun and then the flow
becomes so weak that we can really only deal with short wave
location and accompanying rainfall in a probabilistic sense.
Coastal Hazard Potential Days 3 and 4...None.
&&
.FIRE WEATHER...
Continued wet across southern and eastern Interior with drier and
warmer conditions in the northwest Interior. Expect isolated
thunderstorms a a few lightning strikes today and Sat...except LAL
3 Sat in eastern Zone 216...western 221 and 227. Sun could see LAL
3 over the eastern Interior but uncertain at this point so left it
as LAL 2 for Sun.
&&
.HYDROLOGY...
The past 36 hrs saw .10 to .25 inch of rain fall over the eastern
Interior south of Circle with up to .50 inch in the hills north of
Fox and hills east of Delta Junction...while Denali Park had
between .50-1.5 inch. Expect another .50 to 1 inch over zones 221
225 and 227 through Sat with the heaviest amounts in Denali Park.
This will keep small stream and rivers in Denali high through the
weekend and could cause mud and rock slides through the weekend.
There is a potential for heavy rain in zones 224 and 226 SE of
Tok Sun night and Mon but still much uncertainty on this.
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory for PKZ245.
&&
$$
JB JUL 16
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
533 AM AKDT FRI JUL 1 2016
.SHORT TERM...The biggest story over the next 24 hours is the
ongoing glacial dam release from Suicide Basin into Mendenhall
Lake and River. This will be covered further in the hydrology
section below.
As for the weather, the main feature is a 1000 mb low pressure
system currently in the southeast gulf which will gradually weaken
while moving north to near Cape Fairweather by late tonight. A
secondary wave of low pressure will develop southwest of Haida
Gwaii late tonight but is expected to remain south of the area.
Stratiform rainfall is currently ongoing across the southern half
of the panhandle aided by warm air advection in association with
the advancing low. This will continue to spread northward through
the day reaching the Juneau area this morning and the far northern
panhandle this afternoon. Precipitation chances will remain high
throughout the next 24 hours across all of Southeast Alaska.
Expecting rainfall totals to generally range from one half of an
inch to an inch with heaviest amounts over the southern panhandle.
This system will enhance winds over the southern half of the area
but am only expecting 10 to 20 mph for the land areas and 20-25 kt
for the inner channels. Decreased winds across the far northern
panhandle as a parallel pressure gradient to Northern Lynn Canal
will lead to lighter winds.
Used the 06z NAM and Hi-Res model guidance for updates to the
short term period. Forecaster confidence is above average.
.LONG TERM...Through the weekend, generally a zonal flow pattern
in place across the north Pacific aloft. The closed low at 500 mb
over the Gulf of Alaska weakens and moves into western Canada
Monday while a broad weak ridge aloft forms over the western gulf.
Weak to null flow aloft over the northern panhandle will be in
place headed into early next week. Long range trend for Southeast
Alaska looks to be for a development around mid week to the end of
the week over the gulf.
A surface low near Cape Fairweather is weakening, while a low
moving across the southern gulf along 50N and then curving north
across Haida Gwaii on Saturday. This will spread rain into the
southern half of the panhandle. Saturday evening the low will move
into British Columbia while the low off of Cross Sound dissipates.
The surface pattern across the gulf Friday into Saturday becomes
west to northwest. The potential for low probability showers from
onshore flow will exist along the outer coast Sunday into Monday.
With the main flow pattern to the south of the forecast area not
expecting a significant weather system for the next few days.
&&
.HYDROLOGY...Suicide Basin has released and a flood warning is in
effect for Mendenhall River and Lake until Saturday morning. The
current forecast crest of 11.6 feet is close to the previous
record value of 11.85 feet set in 2014. As of early this morning,
Mendenhall Lake had risen to a stage of 8.5 feet and the rate of
rise is steadily increasing as expected. The level in Suicide
Basin continues to fall rapidly. Residents near the lake or the
river should remain alert and keep track of updates to this event
as they are issued by NWS Juneau.
&&
.AJK Watches/Warnings/Advisories...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ033>036-041>043.
&&
$$
TPS/Bezenek
Visit us at http://www.weather.gov/Juneau
Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
447 AM AKDT FRI JUL 1 2016
.ANALYSIS AND UPPER LEVELS...
Upper level lows are over the western Bering and the southern Gulf
of Ak this morning with the jet remaining well south of the
forecast area. At the surface, lows are near Attu and over the
eastern Gulf. A ridge of high pressure is over the eastern Bering.
The thermal trough/theta-e ridge is draped along the Alaska and
Aleutian ranges and is serving as the focus for showers and even
a few nocturnal thunderstorms.
&&
.MODEL DISCUSSION...
Models remain in agreement that the Gulf upper low will slowly
rotate its way into British Columbia by Sun morning. Easterly
waves moving along the northern flank of the low will interact
with the moisture rich thermal trough/theta-e ridge through the
weekend. This may explain what is happening, but these waves are
poorly timed in model solutions, so exactly when precipitation
initiation and enhancement will occur remains a problem. The
forecast utilizes some Nam and GFS in an attempt to pinpoint some
of the precipitation events.
In the west the surface low will drift and weaken over the western
Aleutians through the weekend. A weak associated front will move
to the central Aleutians during the same period. Again the Nam and
GFS were utilized in the forecast.
&&
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
The last of a series of fairly strong short-waves crossing
westward across Southcentral Alaska this morning will exit to
Southwest Alaska this afternoon bringing an end to widespread
showers and rain. However, as the large upper low over the Gulf
tracks eastward today and tonight, short-waves tracking across
Southwest Alaska will rotate southeastward across Kodiak Island
and the western Gulf bringing widespread showers to that region.
In the wake of the upper level low the flow across the region will
become more and more chaotic, with weak impulses wandering around.
This creates a lot of uncertainty in the forecast. Have used a
broadbrush approach to the precip forecast for tonight through
Saturday night. In this scenario would expect more showers during
the afternoon and evening hours focused along the mountains.
&&
.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
Clouds, rain, and thunderstorms will be the focus for Friday and
Saturday. Widespread showers with embedded thunderstorms will
encompass the Kuskokwim Valley southward through Greater Bristol
Bay today. A lesser chance exists over the Kuskokwim Delta, but
afternoon showers and a slight chance for thunder are possible.
Nearly the same conditions are on tap for Saturday, however, any
thunderstorms will stay confined to the Kuskokwim Valley along
the Alaska Range. For the Delta, most of the shower activity will
be east of Bethel along the Kilbucks. Winds will be on the lighter
side everywhere, and temperatures will be well above average for
this time of year.
Technically speaking...A large upper level low in the gulf
controls the pattern, but the real action is rotating around the
circulation in the form of embedded easterly shortwaves. Feeding
on the baroclinity from the difference between the cooler gulf
airmass and the warmer Interior/Yukon airmass, these waves amplify
and provide the forcing for diurnally enhanced showers and
thunderstorms. Ridging over the northern portion of the state is
breeding warm low level temperatures that will be advected down
into the Southwest Mainland, as well as some juicy dewpoints by
Alaska standards. These conditions are ripe for frequent lightning
over mainly the Kuskokwim Valley and into Bristol Bay today. The
upper level energy lingers through the weekend keeping at least
showers in the forecast.
&&
.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
A weakening system aloft over the Western Bering will bring rain
today from Shemya through the Central Aleutians, and as far east
as the Eastern Aleutians. That system will weaken through the
weekend and not produce meaningful precipitation after today. A
fairly narrow corridor of dense fog will set up today roughly from
Saint Matthew through the Pribilofs and linger through tonight.
&&
.LONG TERM FORECAST (Days 3 through 7)...
On Sunday, the upper level pattern looks to grind to a halt from
the easterly flow of weak disturbances to a much more chaotic
movement. This will be due to the departure of the upper level low
towards the Panhandle by Sunday morning, with no larger scale
features following it. Thus, with everything being weak, any
precipitation that develops Sunday over southern mainland Alaska
will be scattered and weak. The persistence of a mid-level
unstable layer over much of the area will result in some
convection popping up with any showers that develop with enhanced
lift, likely from topographic enhancement.
For the Independence Day holiday, a strong upper level trough will
dig southward across the eastern Bering. Ridging will build east
of it across the Gulf. However, the models are in disagreement
with how quickly the ridge builds, and where the trough axis sets
up over the Bering. Currently, the models agree enough for the
4th of July to suggest a return to southwesterly winds in the
upper levels. Since the disturbances depicted in the models all
remain weak, the weather looks similar to Sunday at this point for
much of mainland Alaska.
Active weather should persist for much of southern Alaska into
midweek as the trough over the Bering moves into mainland Alaska.
However, the model differences and associated forecast
uncertainty only compound with time concerning how quickly and in
what form (open trough or cutoff low), the troughing moves east.
&&
.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.
&&
$$
SYNOPSIS AND MODEL DISCUSSION...DS
SOUTHCENTRAL ALASKA...SEB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...ML
LONG TERM...JW
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
418 AM AKDT FRI JUL 1 2016
.DISCUSSION...
UPPER AIR...
A high pressure ridge currently extends from the Chukotsk
Peninsula eastward across the Brooks Range into northwestern
Canada, with a high center near the Bering Strait. The ridge
will gradually transition to a high pressure center which will
be pushed gradually eastward through Sunday night as a strong
short wave drops southward out of the Russian Arctic Ocean. By
late Sunday night the upper level high will be centered near
Fort Yukon, with the strong short wave trough extending along
178W across the Chukchi Sea and Bering Sea.
A series of weak short wave troughs will move westward across the
southern interior through Saturday. A weak short wave trough is
now moving westward across the central interior. The next short
wave trough is now over the southern Yukon Territory and will
move to the Alcan border by Friday morning then fracture into
two troughs. The southern piece of the trough will continue to
move westward and gradually deepen over the lower Kuskokwim Valley
and southeastward Friday evening. The northern piece of the trough
will stall out over the eastern interior Friday night and
gradually weaken Saturday.
SURFACE...
A 1007 mb low centered near Northway will deepen to a 1001 mb
low about 100 miles east of Northway by this afternoon, then
remain nearly stationary through Saturday. A weak thermal
trough will develop across the northern interior Saturday.
INTERIOR...
Areas or bands of showers and thunderstorms associated with the
short wave troughs aloft will move westward across the southern
interior and the Alaska Range, otherwise there will be isolated
to scattered showers and isolated thunderstorms over most areas
through the weekend. The heaviest rainfall today will likely be
over Denali and the lower Kuskokwim Valley. The heaviest rainfall
amounts tonight are expect to be in the lower Kuskokwim valley and
in nearby area of the middle Yukon Valley. More showers and
isolated thunderstorms are expected over much of the interior
Saturday, and over much of the southern and eastern interior
Sunday.
ARCTIC SLOPE AND BROOKS RANGE...
Areas of fog near the coast during the late night and
early morning hours, otherwise no significant weather
expected through Sunday. Warm temperatures in the interior with
highs as high as the low to mid 70s.
WEST COAST...
No significant weather expected through Sunday. Some
coastal areas may see areas of fog.
Coastal Hazard Potential Days 3 and 4...None.
&&
.FIRE WEATHER...
Some warming is expected in the interior over the weekend...with
highs approaching or reaching 80 in some northern interior areas.
Minimum humidities could approach 30 percent in the northern
interior. Minimum humidities in the southern interior likely to
remain at 35 percent or above.
&&
.HYDROLOGY...
Additional rainfall amounts of 0.5 to 1 inch are expected
in Denali and the lower Kuskokwim Valley today. Northern parts of
the Upper Tanana Valley and Fortymile country may see up to 0.5
inch, with local amounts of 0.75 inch possible. Locally heavier
amounts will be possible in Denali and the lower Kuskokwim Valley
today, but the location of the amounts remains uncertain due to
the convective nature of the precipitation.
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
Small craft advisory for PKZ245.
&&
$$
RF JUN 16
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
418 AM AKDT FRI JUL 1 2016
.DISCUSSION...
UPPER AIR...
A high pressure ridge currently extends from the Chukotsk
Peninsula eastward across the Brooks Range into northwestern
Canada, with a high center near the Bering Strait. The ridge
will gradually transition to a high pressure center which will
be pushed gradually eastward through Sunday night as a strong
short wave drops southward out of the Russian Arctic Ocean. By
late Sunday night the upper level high will be centered near
Fort Yukon, with the strong short wave trough extending along
178W across the Chukchi Sea and Bering Sea.
A series of weak short wave troughs will move westward across the
southern interior through Saturday. A weak short wave trough is
now moving westward across the central interior. The next short
wave trough is now over the southern Yukon Territory and will
move to the Alcan border by Friday morning then fracture into
two troughs. The southern piece of the trough will continue to
move westward and gradually deepen over the lower Kuskokwim Valley
and southeastward Friday evening. The northern piece of the trough
will stall out over the eastern interior Friday night and
gradually weaken Saturday.
SURFACE...
A 1007 mb low centered near Northway will deepen to a 1001 mb
low about 100 miles east of Northway by this afternoon, then
remain nearly stationary through Saturday. A weak thermal
trough will develop across the northern interior Saturday.
INTERIOR...
Areas or bands of showers and thunderstorms associated with the
short wave troughs aloft will move westward across the southern
interior and the Alaska Range, otherwise there will be isolated
to scattered showers and isolated thunderstorms over most areas
through the weekend. The heaviest rainfall today will likely be
over Denali and the lower Kuskokwim Valley. The heaviest rainfall
amounts tonight are expect to be in the lower Kuskokwim valley and
in nearby area of the middle Yukon Valley. More showers and
isolated thunderstorms are expected over much of the interior
Saturday, and over much of the southern and eastern interior
Sunday.
ARCTIC SLOPE AND BROOKS RANGE...
Areas of fog near the coast during the late night and
early morning hours, otherwise no significant weather
expected through Sunday. Warm temperatures in the interior with
highs as high as the low to mid 70s.
WEST COAST...
No significant weather expected through Sunday. Some
coastal areas may see areas of fog.
Coastal Hazard Potential Days 3 and 4...None.
&&
.FIRE WEATHER...
Some warming is expected in the interior over the weekend...with
highs approaching or reaching 80 in some northern interior areas.
Minimum humidities could approach 30 percent in the northern
interior. Minimum humidities in the southern interior likely to
remain at 35 percent or above.
&&
.HYDROLOGY...
Additional rainfall amounts of 0.5 to 1 inch are expected
in Denali and the lower Kuskokwim Valley today. Northern parts of
the Upper Tanana Valley and Fortymile country may see up to 0.5
inch, with local amounts of 0.75 inch possible. Locally heavier
amounts will be possible in Denali and the lower Kuskokwim Valley
today, but the location of the amounts remains uncertain due to
the convective nature of the precipitation.
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
Small craft advisory for PKZ245.
&&
$$
RF JUN 16
Southcentral and Southwest Alaska Forecast Discussion...CORRECTED
National Weather Service Anchorage AK
1108 PM AKDT THU JUN 30 2016
Corrected extended discussion
.ANALYSIS AND UPPER LEVELS...
The upper levels are starting to look like a mixed bag of goodies. The ever
present upper level low spinning south of the gulf is slowly weakening but is
continuing to eject shortwaves around it. The first of these waves moved across
Southcentral last evening. The next is to the Northwest of PAYA and
is noted on upper level analysis as an enhanced bubble of moisture and
as a wiggle in the upper level analysis. This wave will move across
the ALCAN border and across the Copper River Basin this afternoon. As
of 2130z(1:30pm AKDT), showers are already beginning to form. This easterly
wave will wrap around the low and slide across the Anchorage and Kenai
areas tonight. A much more potent wave is easily identified in water
vapor imagery near 49N 141W. As is the case with nearly stationary lows
and these easterly waves that get ejected around, timing and placement
has been a challenge. This strong wave is now progged to shift east
and impact SE AK and BC. Farther west, a ridge between the Gulf low
and a weakening Bering low is becoming pinched off as it retreats into
the interior of Alaska. A strong upper level jet remains well south
of the forecast area. At the surface, progress is being made on moving
the nearly stationary low out of the gulf. A stalled out front stretches
from a low in the Bering and southeast across the Akpen.
&&
.MODEL DISCUSSION...
All models are in pretty good agreement in the short term today. As briefly
touched on in the analysis...the upper level low in the Gulf will shift
east into the weaken. All of the models have varying levels of agreement
with the shortwave strength and timing moving around the lows. The biggest
trend from yesterday was slowing down the timing of the onset of the
biggest rainmaker over Anchorage. The latest 18z runs of the NAM and
GFS are showing a 9-12z time frame while the HRRR is hinting at an early
start, between 5 and 6z. Judging by past performance of the HRRR and
how poorly the major models play temporally, confidence in timing is
low. However, all models are consistent with bringing in a healthy amount
of rain across the region.
&&
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
Increasing mass ascent ahead of a low amplitude short wave trough
over the Western Yukon and Eastern Copper Basin is beginning to
manifest itself as increasing convective showers across the
region. As the shortwave propagates west tonight, showers will
begin to congeal into a large area of stratiform rain which will
impact all of Southcentral tonight with brief periods of heavy
rainfall. The heaviest axis of rain will likely occur across the
Copper Basin into the Mat-Su Valleys, although areas along the
Kenai and into Anchorage will also see the potential for brief
heavy rains overnight. Thunderstorms have formed already along the
Kenai Range, and they will also be possible along the Talkeetnas
and Alaska Range as well as along the Chugach in the evening. The
shortwave trough will elongate and quickly move west Friday, with
most rain moving into Southwest Alaska by the afternoon. Showers
will develop in the afternoon behind the main low, but these will
be mainly along mountains and rather limited given lack of
instability. Saturday will be warmer as broad cyclonic flow sets
up over the region, with more afternoon showers but slightly
warming temperatures.
&&
.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
The upper level low over the Gulf continues to bring easterly flow
with embedded shortwaves over Southwest Alaska. This combined
with the unstable environment is helping to kick off thunderstorms
over the area through Friday. The most likely times for thunderstorms
are during peak heating and as the shortwaves move through. The
shortwaves look to move through this evening, Friday morning and
Friday evening. Friday will also see heavier rain from the
Kuskokwim Valley south towards Bristol Bay and east towards the
Alaska and Aleutian Ranges. Saturday will see a lesser chance for
thunderstorms with the most likely area over the Kuskokwim Vally
but rain will still be likely from the valley through Bristol Bay.
&&
.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
A broad low over the Western Aleutians will last through the
weekend slowly tracking east and bringing rain to the area. Areas
from the Alaska Peninsula through the Pribilof Islands will be
under the effects of weak ridging providing more fair conditions
than areas to the west.
&&
.LONG TERM FORECAST (Days 3 through 7)...
On Sunday, the upper level pattern looks to grind to a halt from
the easterly flow of weak disturbances to a much more chaotic
movement. This will be due to the departure of the upper level low
towards the Panhandle by Sunday morning, with no larger scale
features following it. Thus, with everything being weak, any
precipitation that develops Sunday over southern mainland Alaska
will be scattered and weak. The persistence of a mid-level
unstable layer over much of the area will result in some
convection popping up with any showers that develop with enhanced
lift, likely from topographic enhancement.
For the Independence Day holiday, a strong upper level trough will
dig southward across the eastern Bering. Ridging will build east
of it across the Gulf. However, the models are in disagreement
with how quickly the ridge builds, and where the trough axis sets
up over the Bering. Currently, the models agree enough for the
4th of July to suggest a return to southwesterly winds in the
upper levels. Since the disturbances depicted in the models all
remain weak, the weather looks similar to Sunday at this point for
much of mainland Alaska.
Active weather should persist for much of southern Alaska into
midweek as the trough over the Bering moves into mainland Alaska.
However, the model differences and associated forecast
uncertainty only compound with time concerning how quickly and in
what form (open trough or cutoff low), the troughing moves east.
&&
.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.
&&
$$
SYNOPSIS AND MODEL DISCUSSION...SS
SOUTHCENTRAL ALASKA...JA
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...DK
LONG TERM...JW
AREA FORECAST DISCUSSION
National Weather Service San Diego CA
144 PM PDT FRI JUL 1 2016
.SYNOPSIS...
Monsoonal moisture and instability aloft will continue the
possibility of scattered showers and thunderstorms over portions
of the mountains and deserts through this evening. A low pressure
trough along the west coast will lower high temperatures to normal
or below seasonal normals, create breezy southwesterly winds in
the mountains and deserts, a moderate to deep marine layer and dry
weather Saturday through next Thursday.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
At 1 PM PDT, water vapor imagery displayed an upper-level ridge
over Texas, and an upper-level trough over Northern California.
Visible satellite showed low clouds along the coast, and cumulus
over mountain peaks. Composite radar showed a thunderstorm just
southeast of Big Bear, and a thunderstorm south of Barstow. A 12
C marine layer inversion on the 01/1200 UTC KNKX sounding will
make it difficult for areas along the beach and over the waters to
clear today. Most unstable CAPE of 500-1000 J/KG, precipitable
water of 1.1-1.3 inches and diurnal heating will combine to
continue a chance of thunderstorms over the mountains and deserts
through early evening. Heavy downpours, urban and small stream
flooding, gusty winds and frequent lightning are possible where
storms develop. Isolated flash flooding is possible where
stationary storms develop.
The aforementioned trough will linger along the West Coast this
weekend into the middle of next week. This will help lower high
temperatures to near normal to slightly below normal today through
the middle of next week. Dry SW flow aloft will eliminate chances
for afternoon thunderstorms tomorrow through next Thursday. A deep
marine layer will push night/morning low clouds and fog far into
the valleys tonight. The marine layer will become slightly more
shallow through next week, limiting the extent of the clouds and
fog into the valleys each night. Breezy southwesterly winds will
develop each afternoon through mountain passes and over the
deserts.
&&
.AVIATION...
012017Z...Coast/Valleys...Through 02/0000 UTC, mostly SKC and
unrestricted vis, except within 3-5 SM of the coast where BKN-OVC
clouds 1300-2300 ft MSL will likely linger. 02/0000-1500 UTC,
stratus re-developing 20-25 SM inland and perhaps up to 25-40 SM
inland with bases 1100-1800 ft MSL and tops around 2500 ft MSL.
Areas of 3-5 SM vis over inland mesas. Local vis AOB 1 SM possible
over far inland valleys, such as KRNM and KRIV. Forecast confidence
of stratus occurrence and timing at KSAN, KCRQ and KSNA is high,
with low-to-moderate confidence for KONT and low confidence on
exactly how far inland the stratus will spread.
Mountains/Deserts...Isol-sct thunderstorms/showers in the mountains,
high deserts and possibly lower deserts through 02/0300 UTC with SCT-
BKN cloud bases around 10000 ft MSL, tops around 20000 ft MSL and CB
tops to 40000 ft MSL. Otherwise, mostly SKC and unrestricted vis
will prevail through Saturday morning.
&&
.MARINE...
No hazardous marine weather is expected through Tuesday.
&&
.BEACHES...
Latest nearshore buoy reports show a 4-5 ft/17 second swell from 200
degrees. Surfline shows 4-7 foot surf in Orange County and 3-5 foot
surf in San Diego county being reported today. Surf around these
heights, with locally higher sets, should continue this afternoon,
along with strong rip currents. Although the swell and surf will
gradually lower Saturday through Independence Day, with large beach
crowds expected and rip currents still likely a concern, hazardous
swimming conditions are likely to continue. The Beach Hazards
Statement has been extended through Mon July 4.
&&
.SKYWARN...
Skywarn activation is requested for San Bernardino County.
Although activation is not requested for Riverside, San Diego or
Orange counties at this time, weather spotters are encouraged to
report significant weather conditions as they occur.
&&
.SGX Watches/Warnings/Advisories...
CA...Beach Hazards Statement through Monday evening for Orange County
Coastal Areas-San Diego County Coastal Areas.
PZ...None.
&&
$$
PUBLIC...JJT
AVIATION/MARINE/BEACHES...Harrison
Area Forecast Discussion
National Weather Service Phoenix AZ
145 PM MST FRI JUL 1 2016
&&
.SYNOPSIS...
A combination of lingering monsoon moisture and weak weather
disturbances moving eastward across the desert southwest will bring
chances for showers and thunderstorms tonight across sw and south-
central Arizona, and on Saturday, over the higher terrain of eastern
Arizona. A return to drier southwest flow aloft will begin to take
over starting Saturday and end any rain chances starting Sunday.
High temperatures will steadily climb into the weekend and early
next week as the atmosphere becomes drier. The dry and warm
conditions will likely last through much of next week.
&&
.DISCUSSION...
.late this afternoon/tonight....
A bit of a break in action across our cwa this hour, with the shower
and thunderstorm activity that affected parts of South-Central AZ
this morning having moved well off to the south and east, now
extending northward from eastern Pima/Cochise counties to eastern
Gila County. The shower activity this morning is currently holding
down temperatures a bit over South-Central AZ, with Phoenix Sky
Harbor airport only up to 90 degrees at noon, under clear skies.
Further to the west, over western Maricopa and La Paz/Yuma counties,
fields of CU can be seen developing on latest visible satellite
imagery, over areas that stayed dry this morning, allowing
temperatures to rise well up into the 90s at midday. Surface
dewpoints remain elevated at most lower desert locations, well up
into the 60s to near 70. Up to the north, new thunderstorms can be
seen on radar developing over Yavapai County.
As far as the forecast for this afternoon/evening is concerned, in
spite of normally unfavorable westerly flow that is developing over
the region as an upper trof approaches the CA coast, the combination
of lingering low-level moisture and another shortwave approaching
from the northwest will likely produce another round of convective
activity across South-Central and SW AZ later this
afternoon/evening. Today`s situation appears to be more like a
transition event rather then a classic monsoon case, with the GFS
forecast soundings showing 1500-2000 J/KG of CAPE (with little or no
CIN), and 25-30 knots of bulk shear over the region through this
evening. The 12Z WRFGFS, which did a good job with this morning`s
convective activity, is showing shower/thunderstorm development
later this afternoon across northern La Paz and NW Maricopa
Counties, with this activity moving into the Greater Phoenix area
this evening as the shortwave trigger moves eastward across northern
AZ. Given all this available convective energy and intrusion of
drier air above 600mb, a few of the storms could become severe, with
very strong downburst winds, heavy downpours, localized flooding,
and even small hail possible. Thus, have raised POPS this evening
well up into the chance range across the lower deserts of South-
Central AZ, and into the likely range over southern Gila County.
.Saturday through next Friday...
This weekend will bring a continued drying westerly flow, but enough
lingering low level moisture should exist for some isolated eastern
Arizona high terrain afternoon showers and thunderstorms. The
possibility of any activity over the lower deserts is pretty slim
due to the westerly steering flow and PWATS dropping down to around
1.25 inches. By Sunday, enough dry air should be in place for there
to be little chance of any storms even over the high terrain.
Temperatures this weekend will be on the upswing with the drier
conditions and clear to mostly clear skies as highs climb back toward
normal readings.
Next week looks to be mostly quiet as far as any storm potential as
the upper high center generally stays to our southeast providing us
with westerly or southwesterly flow. Temperatures should peak by
Tuesday or Wednesday with some lower desert spots reaching 110F for
highs. 500mb heights do climb to around 592dm and 850mb temperatures
near 30C, but at this point it does not appear enough to hit
excessive heat levels. There is potential for a return of some
monsoonal moisture as early as Wednesday, but the past few model
runs are showing this to be a very brief episode with more dry air
quickly moving in by the end of the week. At least for now slight
chance PoPs over the high terrain for Thursday and Friday seem
warranted.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
Southeasterly flow will veer to southwesterly during the afternoon,
but wind speeds will generally remain at or below 10 kt. Meanwhile, latest
convective guidance is pointing towards an increased potential for
showers and thunderstorms across the Phoenix area later this
evening. Any storms that develop will be capable of producing strong
gusty winds and brief heavy rain. Model consensus is that the most
likely wind shift associated with the storms will be from the
northwest. Improving conditions are anticipated after 09z.
Southeast California/Southwest Arizona including KIPL and KBLH:
The active weather will generally remain east of KIPL, but may clip
KBLH this afternoon. Thunderstorms are generally not expected,
however strong storms across western AZ may produce a wind shift out
of the north or east at KBLH this evening. Otherwise, mostly clear
skies are expected with a southerly component to the flow prevailing
through early Saturday.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Monday through Friday: The monsoon high will rebuild across
southeastern Arizona Monday, resulting in above normal temperatures
and generally dry conditions. An increase in moisture is expected
Wednesday as the high shifts eastward. Drier westerly flow across
southeastern California will battle deeper moisture across
southeastern Arizona through the remainder of the week, with showers
and thunderstorms mainly relegated to southern and eastern Arizona.
Near normal temperatures are expected mid to late 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...Percha/Kuhlman
AVIATION...Hirsch
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Phoenix AZ
1143 AM MST FRI JUL 1 2016
.UPDATE...Updated Aviation discussion.
&&
.SYNOPSIS...
Another day or two of monsoon moisture will bring chances for
showers and thunderstorms today and again on Saturday over the
eastern Arizona high terrain. A return to drier southwest flow aloft
will begin to take over starting Saturday and end any rain chances
starting Sunday. High temperatures will steadily climb into the
weekend and early next week as the atmosphere becomes drier. The dry
and warm conditions will likely last through much of next week.
&&
.DISCUSSION...
A rather wet morning across parts of South-Central AZ this morning,
as a weak mid-level shortwave helped to trigger showers and isolated
thunderstorms across Pinal and eastern Maricopa counties. Rainfall
amounts have so far been on the light side, mainly in the 0.05-0.25
inch range so far this morning. These showers also pushed
temperatures down this morning across this region, with Phoenix Sky
Harbor seeing a low of 79. The main impact from these morning
showers for the rest of today will to likely retard/delay to
development of new convection this afternoon/evening across this
region. A far as the forecast for the rest of our cwa is concerned,
have decided to increase pops a bit across La Paz and NW Maricopa
counties, since these areas have already cleared out, with the
latest HRRR high-res model showing the development of showers and
thunderstorms as outflows from the remains of strong thunderstorms
that occurred last night over NW AZ move into the region. The other
changes were made to the hourly temp/dewpoint grids to better
reflect current trends.
&&
.PREVIOUS DISCUSSION...
After a rather quiet, cool and cloudy Thursday across southern
Arizona, we should see a rebound in monsoon storm activity this
afternoon and evening. Current analysis shows two separate mid level
circulations across the region, one planted right over southeast
Arizona and the other further to the northwest over southern Nevada.
Moisture levels remain quite high with the 00Z KPHX raob showing a
PWAT of 1.68 inches, but very warm mid levels continue to bring weak
lapse rates and rather meager instability. The mid level circulation
over southeast Arizona is however providing enough forcing to result
in periodic showers stretching as far west as Phoenix. These showers
should continue through around 12Z, but will likely diminish
thereafter as the vorticity center lifts to the northeast.
Westerly drying flow has already overtaken southeast California and
portions of southwest Arizona and will slowly spread across the rest
of southern Arizona throughout today. By this afternoon, the mid and
upper levels will have dried out for the most part except for eastern
Arizona. The drying will likely help us to see more storm development
today versus yesterday as we see quite a bit of clearing skies and
much better heating. The lingering low level moisture will still be
enough to spark off some weak thunderstorms this afternoon, but most
will likely start out over higher terrain spots, especially north of
Phoenix. Steering flow will be generally out of the west at around
10-20 mph, so not especially conducive for outflow propagation into
the lower deserts of south-central Arizona. Hi-res models do indicate
high terrain storms north of Phoenix sending some outflows into the
Phoenix metro which should be enough to spark some isolated storms
over the deserts. Weak winds aloft and the lack of any significant
upper level support should keep storms on the weak side and with
PWATS dropping to below 1.5 inches the flooding threat will be very
minimal. Temperatures today should improve over yesterday`s readings
over south-central and eastern Arizona while similar readings will be
seen over our western zones.
This weekend will bring a continued drying westerly flow, but enough
lingering low level moisture should exist for some isolated eastern
Arizona high terrain afternoon showers and thunderstorms. The
possibility of any activity over the lower deserts is pretty slim
due to the westerly steering flow and PWATS dropping down to around
1.25 inches. By Sunday, enough dry air should be in place for there
to be little chance of any storms even over the high terrain.
Temperatures this weekend will be on the upswing with the drier
conditions and clear to mostly clear skies as highs climb back toward
normal readings.
Next week looks to be mostly quiet as far as any storm potential as
the upper high center generally stays to our southeast providing us
with westerly or southwesterly flow. Temperatures should peak by
Tuesday or Wednesday with some lower desert spots reaching 110F for
highs. 500mb heights do climb to around 592dm and 850mb temperatures
near 30C, but at this point it does not appear enough to hit
excessive heat levels. There is potential for a return of some
monsoonal moisture as early as Wednesday, but the past few model
runs are showing this to be a very brief episode with more dry air
quickly moving in by the end of the week. At least for now slight
chance PoPs over the high terrain for Thursday and Friday seem
warranted.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
Southeasterly flow will veer to southwesterly during the afternoon,
but wind speeds will generally remain at or below 10 kt. Meanwhile, latest
convective guidance is pointing towards an increased potential for
showers and thunderstorms across the Phoenix area later this
evening. Any storms that develop will be capable of producing strong
gusty winds and brief heavy rain. Model consensus is that the most
likely wind shift associated with the storms will be from the
northwest. Improving conditions are anticipated after 09z.
Southeast California/Southwest Arizona including KIPL and KBLH:
The active weather will generally remain east of KIPL, but may clip
KBLH this afternoon. Thunderstorms are generally not expected,
however strong storms across western AZ may produce a wind shift out
of the north or east at KBLH this evening. Otherwise, mostly clear
skies are expected with a southerly component to the flow prevailing
through early Saturday.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Sunday through Thursday...
Increasing high pressure beginning Sunday is expected to usher in a
slightly drier and warmer weather pattern for most of the week. As
slightly below normal afternoon high temperatures on Sunday increase
to near normal by Tuesday, minimum humidities in the 15 to 25 percent
range will dip to the 10 to 20 percent range on Monday before easing
back up into the 15 to 25 percent range by Wednesday. Expect breezy
southerly to southwesterly winds on Tuesday with gusts to 18 mph to
become breezy to windy on Wednesday with gusts up to 28 mph,
especially in the the lower Colorado river valley. Expect overnight
recoveries to be mostly fair to occasionally good. A slight return in
moisture may begin midweek, allowing for at least slight chances of
thunderstorms mainly over the higher elevations of the Tonto
Foothills and S. Gila county by Thursday.
&&
.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...Percha/Kuhlman
AVIATION...Hirsch
FIRE WEATHER...Nolte/Sawtelle
AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
945 AM PDT FRI JUL 1 2016
.SYNOPSIS...
Strengthening onshore flow and a deepening marine layer will bring
a cooling trend into the weekend. Marine layer clouds will reach
into the valleys, however warm and dry conditions will prevail in
the mountains and deserts. A gradual warmup is expected early next
week as high pressure builds in over the desert Southwest.
&&
.UPDATE...Nothing really new to add to what is basically a pretty
bland forecast through the weekend at least. A very weak trough
will slowly advance east through California this weekend. Very
minimal impacts locally other than the usual deepening of the
marine lyr and cooler temps. Heights and thicknesses only drop
30-40m through Sunday so overall the air mass isn`t cooling
significantly. But the increase in marine lyr depth and onshore
push will be enough to force temps down back to near normal levels
this weekend. Today we`ll see a few cu over the eastern
mountains as there`s still some lingering moisture and
instability from storms that developed to our east late yesterday
and overnight, but not enough for any storms in our area.
&&
.SHORT TERM...(TDY-SUN)
Overall, 00Z models in good synoptic agreement through the period.
At upper levels, weak trough will linger across California through
the weekend. Near the surface, moderate onshore flow will
continue.
Forecast-wise, the main concerns in the short term will be the
marine layer stratus and temperatures. With the upper trough
lingering and moderate onshore flow, the marine inversion should
deepen a bit from day-to-day. So, will expect stratus/fog to push
into the coastal valleys each night/morning. Each afternoon, the
stratus should dissipate nicely although some beach areas could
be slow to clear. Other than the marine layer stratus, skies
should remain clear as southwest flow aloft keeps any moisture to
the east.
As for temperatures, only minor changes are expected from day-
to-day. There will be some slight cooling today/Saturday then a
bit of warming on Sunday. Overall, temperatures for most areas
will likely be a couple of degrees below seasonal normals through
the weekend.
With the moderate onshore flow, there will be some gusty afternoon
and evening winds across the mountains and deserts. At this time,
winds look to remain below advisory levels although some isolated
areas (such as Lake Palmdale) could experience some gusts near
advisory levels.
.LONG TERM...(MON-THU)
For the extended, 00Z models continue to exhibit decent synoptic
agreement. At upper levels, the area will be between a ridge over
the central states and a trough over the Pacific Northwest. Near
the surface, weak to moderate onshore flow looks to continue.
Forecast-wise, things will remain on the quiet side through the
period. Due to the upper level pattern, southwest flow will
prevail through the week which will keep any monsoonal moisture
well east of the state. So, the only clouds of note will continue
to be the marine layer stratus which should continue to push into
the coastal valleys each night/morning. As for temperatures, there
will be a gradual warming trend as thicknesses rise and the marine
influence decrease slightly each day.
&&
.AVIATION...01/12Z...
At 11Z at KLAX...the marine layer was 2200 feet deep. The top of
the marine inversion was 4700 feet with a temperature of 24
degrees Celsius.
Low clouds have pushed into all coastal and valley areas this
morning, with the exception of the Santa Clarita Valley and the
interior valleys of SLO County. Conditions were mostly IFR from
VTU County northward, and MVFR across L.A. county, except locally
IFR in the valleys. Some IFR conds may push into the Salinas
Valley by daybreak. Expect somewhat slower clearing today, with
VFR conds in the valleys by late morning, and by early afternoon
across the coastal plain. Some cigs could linger near the beaches
through the day. Expect stratus to arrive this evening across the
coastal plain, pushing into the valleys by midnight. Conds tonight
should be mostly MVFR, except IFR in the foothills and on the
Central Coast.
KLAX...Moderate confidence in the 12z TAF. There is a 20 to 30
percent chance that cigs will linger through the afternoon.
There is a 20 percent chance that east winds will exceed 8 knots
between 13z and 17x this morning.
KBUR...Moderate to high confidence in the 12z TAF. There is a 20
percent chance that cigs will clear as early as 16z or arrive as
early as 04z tonight.
&&
.MARINE...01/900 AM...
Small craft advisory for hazardous sea conditions will exist
through late tonight north of Point Conception. The fetch area is
near shore north of the area and the winds are expected to
diminish tonight. otherwise small craft advisory for winds are not
expected through next week Tuesday. Extra currents and surging
along exposed south facing shores will persist through Saturday.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 8 PM PDT this evening
For zones 40-41-87. (See LAXCFWLOX).
PZ...Small Craft Advisory for hazardous seas in effect until
midnight PDT tonight For zones 645-670-673. (See LAXMWWLOX).
&&
$$
PUBLIC...MW/RAT
AVIATION...DB
MARINE...30
SYNOPSIS...Sweet
weather.gov/losangeles
Area Forecast Discussion
National Weather Service San Francisco Bay Area
927 AM PDT FRI JUL 1 2016
.SYNOPSIS...A slight cooling trend remains on track into the
weekend, especially inland, with temperatures near seasonal
averages through the 4th of July Holiday Weekend. Late night and
morning low clouds will give way to mostly sunny conditions each
afternoon at least into early next week.
&&
.Discussion...as of 9:30 AM PDT Friday...Typical summer day across
the region with a moderate onshore surface gradient and widespread
clouds at the coast plus adjacent valleys. Satellite animation
shows clouds are slowly burning off around the edges and should
retreat to the coast by late in the morning. Highs will range
from 60s to lower 70s at the coast with mid 70s to upper 80s
inland. Additional cooling is expected over the weekend
particularly for inland spots as 925 MB temps drop 2 to 4C while
the marine layer remains around 2000 feet.
Current forecast appears on track. No major updates planned.
.Previous Discussion...Satellite IR fog product imagery is
showing a similar pattern to yesterday morning at this time with
stratus clinging along the coast from the Golden Gate south
through coastal Monterey County. Stratus is extending inland over
portions of San Mateo County, and extensively in through the
Monterey Bay and Salinas Valley. Light fog is being reported at
Half Moon Bay, Watsonville and at the Monterey airport, with
visibility as low as 1 1/2 miles at times. The fort ord profiler
indicates a marine layer depth of 1500 feet, and surface pressure
gradients are remaining strong northerly as well as onshore with
5.6 mb from ACV to SFO, and 3.3 mb from SFO to SAC.
A baggy upper level trough centered along the west coast will
maintain a cooling trend across the area as well as keep
temperatures cooler than seasonal normals through the holiday
weekend and into next week. Friday is expected to be the warmest
day of the week, especially inland where temperatures will range
from the 80s to upper 90s in the warmest areas. By Saturday,
temperatures are expected to be in the 60s coast...70s around the
bay...and 80s to mid 90s inland. Only a few day-to-day minor temp
fluctuations are expected, but overall the coming week should be
very mild for early July. Night and morning coastal low clouds and
fog and occasional drizzle can be expected through the forecast
period.
&&
.AVIATION...as of 4:30 AM PDT Friday...N-S pressure gradients are
weakening and stratus has developed off the San Mateo coast. SFO
reporting SCT and may occasionally become BKN between 13Z and 16Z.
Clouds are expected to be mainly around SFO with most of the
approach remaining clear. Low clouds are into Monterey bay and
will stay in place through at least 18z.
Vicinity of KSFO...Possible MVFR cigs between 13Z and 16Z.
West to northwest winds to 15 kt after 20Z.
SFO Bridge Approach...vfr overnight except for some morning cigs
from about the San Mateo Bridge north through 16Z.
Monterey Bay Terminals...IFR cigs at kmry/ksns through 18-19z.
&&
.MARINE...as of 09:16 AM PDT Friday...Moderate to strong and
occasionally gusty northwest winds will persist primarily over the
northern waters through the holiday weekend. the strongest gusts
may become gale force. these strong winds will generate hazardous
conditions due to steep fresh swell for portions of the northern
waters. winds will be lighter over the southern waters near shore.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tday...SCA...Pt Arena to Pigeon Pt 10-60 nm
SCA...Pt Arena to Pt Reyes 0-10 nm
SCA...SF Bay from 1 PM
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm until 11 AM
&&
$$
PUBLIC FORECAST: Bell
AVIATION: W Pi
MARINE: DRP
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Area Forecast Discussion
National Weather Service San Francisco Bay Area
927 AM PDT FRI JUL 1 2016
.SYNOPSIS...A slight cooling trend remains on track into the
weekend, especially inland, with temperatures near seasonal
averages through the 4th of July Holiday Weekend. Late night and
morning low clouds will give way to mostly sunny conditions each
afternoon at least into early next week.
&&
.Discussion...as of 9:30 AM PDT Friday...Typical summer day across
the region with a moderate onshore surface gradient and widespread
clouds at the coast plus adjacent valleys. Satellite animation
shows clouds are slowly burning off around the edges and should
retreat to the coast by late in the morning. Highs will range
from 60s to lower 70s at the coast with mid 70s to upper 80s
inland. Additional cooling is expected over the weekend
particularly for inland spots as 925 MB temps drop 2 to 4C while
the marine layer remains around 2000 feet.
Current forecast appears on track. No major updates planned.
.Previous Discussion...Satellite IR fog product imagery is
showing a similar pattern to yesterday morning at this time with
stratus clinging along the coast from the Golden Gate south
through coastal Monterey County. Stratus is extending inland over
portions of San Mateo County, and extensively in through the
Monterey Bay and Salinas Valley. Light fog is being reported at
Half Moon Bay, Watsonville and at the Monterey airport, with
visibility as low as 1 1/2 miles at times. The fort ord profiler
indicates a marine layer depth of 1500 feet, and surface pressure
gradients are remaining strong northerly as well as onshore with
5.6 mb from ACV to SFO, and 3.3 mb from SFO to SAC.
A baggy upper level trough centered along the west coast will
maintain a cooling trend across the area as well as keep
temperatures cooler than seasonal normals through the holiday
weekend and into next week. Friday is expected to be the warmest
day of the week, especially inland where temperatures will range
from the 80s to upper 90s in the warmest areas. By Saturday,
temperatures are expected to be in the 60s coast...70s around the
bay...and 80s to mid 90s inland. Only a few day-to-day minor temp
fluctuations are expected, but overall the coming week should be
very mild for early July. Night and morning coastal low clouds and
fog and occasional drizzle can be expected through the forecast
period.
&&
.AVIATION...as of 4:30 AM PDT Friday...N-S pressure gradients are
weakening and stratus has developed off the San Mateo coast. SFO
reporting SCT and may occasionally become BKN between 13Z and 16Z.
Clouds are expected to be mainly around SFO with most of the
approach remaining clear. Low clouds are into Monterey bay and
will stay in place through at least 18z.
Vicinity of KSFO...Possible MVFR cigs between 13Z and 16Z.
West to northwest winds to 15 kt after 20Z.
SFO Bridge Approach...vfr overnight except for some morning cigs
from about the San Mateo Bridge north through 16Z.
Monterey Bay Terminals...IFR cigs at kmry/ksns through 18-19z.
&&
.MARINE...as of 09:16 AM PDT Friday...Moderate to strong and
occasionally gusty northwest winds will persist primarily over the
northern waters through the holiday weekend. the strongest gusts
may become gale force. these strong winds will generate hazardous
conditions due to steep fresh swell for portions of the northern
waters. winds will be lighter over the southern waters near shore.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tday...SCA...Pt Arena to Pigeon Pt 10-60 nm
SCA...Pt Arena to Pt Reyes 0-10 nm
SCA...SF Bay from 1 PM
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm until 11 AM
&&
$$
PUBLIC FORECAST: Bell
AVIATION: W Pi
MARINE: DRP
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Area Forecast Discussion
National Weather Service Sacramento CA
911 AM PDT FRI JUL 1 2016
.SYNOPSIS...
Hot and mainly dry this week. A slight cooling trend starting
this weekend and continuing through the week. Isolated late day
thunderstorms possible over the Sierra Friday and Saturday.
&&
.DISCUSSION...
Latest Hi-Res models suggest late day shower and/or thunderstorm
activity remaining east of the Sierra crest. As such, have
updated the forecast to show current model trends. No additional
updates required.
.PREVIOUS DISCUSSION...
Water vapor and RAP model 500 mb analysis showed plenty of dry air
with an area of upper level divergence associated with a weak
upper level trough positioned over NorCal overnight. A lack of a
delta influenced breeze has kept temperatures overnight ranging
between the low to mid 70s for much of the valley...with the
northern end of the Sacramento valley in the lower 80s as of 3 am
PDT.
Plenty of sunshine and warm temperatures will continue today
across the forecast area. Smoke from the Trailhead fire near Todd
Valley could bring some haze and patchy smoke today for
surrounding communities. Temperatures in the valley will range
from the upper 90s in the southern Sacramento Valley and Northern
San Joaquin Valley, but temperatures will reach triple digits
again in the northern Sacramento Valley. Higher elevations will
see 70s and 80s today. The latest high resolution model runs have
some showers and thunderstorms developing in the Sierra Nevada
mountains during the afternoon hours, but the placement should be
to the east of the crest. As a result, there are some slight
chances for thunderstorms at the higher elevations mentioned in
the forecast.
Chances for thunderstorms will continue Saturday afternoon for the
Sierra Nevada mountains south of US Highway 50. High temperatures
will continue to be 5 to 10 degrees above normal for the valley. A
shortwave trough moving across the Pacific northwest will bring
slightly cooler temperatures to the valley for Sunday and Monday
with highs in the lower to mid 90s, and dry weather is
anticipated due to a lack of moisture and instability across the
forecast area.
&&
.EXTENDED DISCUSSION (Tuesday THROUGH Friday)
A weak upper trough will persist over the Pacific Northwest into
extreme NorCal next week, resulting in dry weather and near normal
temperatures. Onshore, southwest winds may be breezy over higher
terrain with our typical Delta Breeze impacting the valley.
Expect high temperatures in the 90s across the Valley, with 70s
and 80s over the mountains. JClapp/JBB
&&
.AVIATION...
VFR conditions the next 24 hours. Winds will generally be around
10 kts or less. Winds in northern Sacramento valley for KRDD and
KRBL will switch from northerly this morning to southeasterly in
the afternoon. Otherwise, onshore flow expected for the rest of
the valley/TAF sites. Delta Breeze will increase again this
afternoon and evening. Areas of smoke near the Trailhead fire.
JBB
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service San Diego CA
350 AM PDT FRI JUL 1 2016
.SYNOPSIS...
Southwestern California will remain on the western edge of mid
level monsoonal moisture today with widely scattered thunderstorms
expected for the mountains and upper deserts for this afternoon.
Drying aloft will follow for this weekend through next week as a
trough of low pressure develops near the West Coast. High
temperatures will remain near average. The marine layer and
onshore flow will bring areas of night and morning low clouds and
fog from the coast into portions of the valleys.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Early this morning...a thunderstorm complex was over northeastern
San Bernardino County and far southern Nevada with an outflow
boundary moving southward across San Bernardino County.
Mid level moisture remains centered around 600 mb...with higher
resolution models showing the development of widely scattered
thunderstorms this afternoon near the mountain ridge tops and
along the desert mountain slopes and in the upper deserts...mainly
along and east of interstate 15.
A developing trough of low pressure near the West Coast will
bring drier southwest flow aloft for the weekend into next week
with near seasonal high temperatures. The marine layer and weak
onshore flow will keep coastal areas cooler with areas of night
and morning coastal low clouds and fog extending into portions of
the valleys. Higher resolution models show the marine layer
becoming deep enough for stratus to extend into the far inland
valleys Saturday morning...then becoming gradually shallower
through next week.
&&
.AVIATION...
Coast/Valleys...BKN-OVC stratus 25-30 miles inland will continue
this morning, with clearing in the valleys between 16-18z, and
partial clearing at the coast 18-20z. Bases will be 1000-1700 ft MSL
with tops to 2500 ft MSL. Areas of vis 3-5 mi will occur in the
valleys this morning with local vis below 1 mi vcnty KRNM, KF70 and
KRIV. Confidence of forecast is moderately high.
Mountains/Deserts...Mostly clear skies with unrestricted VIS will
prevail this morning, then areas of SCT-BKN cu/tcu will develop this
afternoon with bases 9000 ft MSL. Isolated thunderstorms mainly
mountaintop based with tops to 45000 ft MSL possible. Sfc wind gusts
to 40 kt possible near any stronger storms. Chance of t-storms
diminishes rapidly by sunset.
&&
.MARINE...
No hazardous marine weather is expected through Tuesday.
&&
.BEACHES...
Latest nearshore buoy reports continue to show a 5-6 ft/18 second
swell from 200 degrees, and swell was mostly 4-6 feet on southwest
facing beaches earlier Thursday. Swell should very gradually lower
later today and through the weekend, though strong dangerous rip
currents will continue through this evening. Most of the surf will
be 5 feet or less by Saturday, though strong rip currents will still
be possible, which could cause issues due to large beach crowds
expected over the holiday weekend. The Beach Hazards Statement
remains in effect through this evening, and may be extended later
today.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX Watches/Warnings/Advisories...
CA...Beach Hazards Statement through this evening for Orange County
Coastal Areas-San Diego County Coastal Areas.
PZ...None.
&&
$$
PUBLIC...17
AVIATION/MARINE/BEACHES...JMB
Area Forecast Discussion
National Weather Service Sacramento CA
334 AM PDT FRI JUL 1 2016
.SYNOPSIS...
Hot and mainly dry this week. A slight cooling trend starting
this weekend and continuing through the week. Isolated late day
thunderstorms possible over the Sierra Friday and Saturday.
&&
.DISCUSSION...
Water vapor and RAP model 500 mb analysis showed plenty of dry air
with an area of upper level divergence associated with a weak
upper level trough positioned over NorCal overnight. A lack of a
delta influenced breeze has kept temperatures overnight ranging
between the low to mid 70s for much of the valley...with the
northern end of the Sacramento valley in the lower 80s as of 3 am
PDT.
Plenty of sunshine and warm temperatures will continue today
across the forecast area. Smoke from the Trailhead fire near Todd
Valley could bring some haze and patchy smoke today for
surrounding communities. Temperatures in the valley will range
from the upper 90s in the southern Sacramento Valley and Northern
San Joaquin Valley, but temperatures will reach triple digits
again in the northern Sacramento Valley. Higher elevations will
see 70s and 80s today. The latest high resolution model runs have
some showers and thunderstorms developing in the Sierra Nevada
mountains during the afternoon hours, but the placement should be
to the east of the crest. As a result, there are some slight
chances for thunderstorms at the higher elevations mentioned in
the forecast.
Chances for thunderstorms will continue Saturday afternoon for the
Sierra Nevada mountains south of US Highway 50. High temperatures
will continue to be 5 to 10 degrees above normal for the valley. A
shortwave trough moving across the Pacific northwest will bring
slightly cooler temperatures to the valley for Sunday and Monday
with highs in the lower to mid 90s, and dry weather is
anticipated due to a lack of moisture and instability across the
forecast area.
&&
.EXTENDED DISCUSSION (Tuesday THROUGH Friday)
A weak upper trough will persist over the Pacific Northwest into
extreme NorCal next week, resulting in dry weather and near normal
temperatures. Onshore, southwest winds may be breezy over higher
terrain with our typical Delta Breeze impacting the valley.
Expect high temperatures in the 90s across the Valley, with 70s
and 80s over the mountains. JClapp/JBB
&&
.AVIATION...
VFR conditions the next 24 hours. Winds will generally be around
10 kts or less. Winds in northern Sacramento valley for KRDD and
KRBL will switch from northerly this morning to southeasterly in
the afternoon. Otherwise, onshore flow expected for the rest of
the valley/TAF sites. Delta Breeze will increase again this
afternoon and evening. Areas of smoke near the Trailhead fire.
JBB
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
347 PM CDT FRI JUL 1 2016
.SHORT TERM...(This Evening through Saturday)
Issued at 344 PM CDT FRI JUL 1 2016
This afternoon a deep mid-level trough was stretched across the
eastern U.S. with surface high pressure situated west of the trough
across the Northern and Central Plains. This west-northwesterly flow
aloft combined with low/mid cloud cover supported cooler conditions
this afternoon with highs topping out in the low/mid 80s. Drier
conditions from the surface high were noted across northeast Kansas
where dewpoint temperatures dropped into the 40s with dewpoints in
the 50s to near 60 degrees elsewhere. With these drier conditions
in place, the onset of precipitation will be slower than originally
expected as it will take longer to overcome the drier air and for
the atmospheric profile to become more deeply saturated. As a
result, have lowered PoPs for eastern Kansas late afternoon into
this evening. There actually is still model uncertainty with the
eastward progression of precipitation tonight into Saturday morning
as some models are showing the better lift holding off until
overnight across north central to east central Kansas as the low-
level jet begins to increase over the area. The larger-scale models
still show showers and thunderstorms overspreading the entire
forecast area overnight, while the early afternoon model runs of the
HRRR and RAP suggest that precipitation may not even advance into
northeast Kansas overnight. If this slower solution pans out, then
PoPs are too high across eastern Kansas for overnight tonight.
However, expect moderate to heavy rainfall rates overnight into
Saturday morning with any precipitation that develops as an embedded
shortwave lifts northeastward over the area. Model soundings show a
deep saturation layer developing with PWAT values upwards of around
2 inches. As a result, rainfall amounts of 1 to 1.5 inches will be
possible across portions of north central, central, and east central
Kansas by Saturday morning. While instability will be limited
through tonight, 0-6km bulk shear values may be upwards of 40-50kts
across north central Kansas, so cannot rule out the potential for a
few strong storms tonight with gusty winds and hail being the
primary hazards.
Morning showers and thunderstorms will lift to the northeast as the
first embedded shortwave exits the area and a surface warm front and
inverted surface trough lift into east central Kansas by early
afternoon. Models show the inverted surface trough becoming more
north-south oriented during the afternoon hours, and this boundary
should provide sufficient lift to support additional widespread
showers and storms across north central and far northeast Kansas by
mid to late afternoon. Model soundings show a deep saturation layer
in place with this second round of storms, with PWAT values rising
into the 2 to 2.5 inch range so expect increasing rainfall rates
over north central Kansas during the mid/late afternoon hours. If we
are able to see some breaks in the cloud cover between the morning
and afternoon rounds of precipitation, conditions may destabilize
enough to increase the concerns for strong to severe storms as 40-
50kts of 0-6km shear should still be in place. With a few rounds of
moderate to heavy rainfall possible, a Flash Flood Watch remains in
effect beginning tonight across the entire outlook area.
As for temperatures, with the warm front lifting into east central
Kansas Saturday afternoon, a decent spread in afternoon temperatures
is likely. There is still some uncertainty with where across east
central Kansas this temperature gradient will be, but the current
forecast has high temperatures ranging from near 70 degrees in far
northeast Kansas to the mid/upper 80s across central and east
central Kansas.
.LONG TERM...(Saturday Night through Friday)
Issued at 344 PM CDT FRI JUL 1 2016
The upper trough over the southwest US is forecast to slowly move
east into the Central Plains on Saturday and then into the
Missouri Valley Saturday night. The upper trough should be strong
enough to produce a surface wave along the stalled frontal
boundary across southern Kansas Saturday afternoon. The upper
trough and associated surface wave moves through the area by
Sunday morning. The 12z NAM was faster with the system compared to
the 12z GFS/ECMWF. The slower movement appears to be associated
with a piece of shortwave energy moving into southern plains
Sunday. In all cases, there is a high probability of a heavy
rainfall event over northeast Kansas Saturday night. Low-level
warm advection over surface boundary, synoptic scale UVV which
should have a very moist airmass in place by that point to work with
with PWAT values around 2 inches. The convective resolving models
(ARW and NMM)produce thunderstorms over the forecast area Saturday
night. The 12z NAM/GFS/ECMWF all produce significant pcpn over the
area, although their maximum amounts are north of the area closer to
the apparent 850 mb warm front. This decreases overall confidence
somewhat, but enough confidence remains for high pops and heavy rain
over the forecast area. The lingering shortwave energy on Sunday
supports keep pops in over the east. Will end the flash flood watch
at 12z Sunday morning over the western counties which by then will
have very low chances of heavy precipitation.
Surface high pressure will be over eastern Kansas on Independence
Day which should result in dry weather and below normal
temperatures.
The 12z GFS is more bullish on building the upper ridge into the
Central Plains compared to the 12z ECMWF. The GFS certainly looks
drier and hotter Tue-Fri next week. Will go with a compromise at
this point with very warm temperatures returning with a chance of
thunderstorms due to warm advection Tuesday night. Thunderstorm
chances return late in the forecast as a weak boundary moves into
the area.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
Issued at 1228 PM CDT FRI JUL 1 2016
VFR conditions are expected throughout the period. Introduce TSRA
at all terminals between 05Z and 07Z. Current thinking is cigs
should remain VFR, although MVFR cigs are possible with any
heavier rain band. Showers and thunderstorms should become lighter
in intensity after 14Z tomorrow morning as the main complex of
showers and thunderstorms exit the area.
&&
.TOP Watches/Warnings/Advisories...
Flash Flood Watch from 7 PM CDT this evening through Sunday
evening for KSZ024-026-038>040-054>056-058-059.
Flash Flood Watch from 7 PM CDT this evening through Sunday
morning for KSZ008>012-020>023-034>037.
&&
$$
SHORT TERM...Hennecke
LONG TERM...Johnson
AVIATION...Baerg
Area Forecast Discussion
National Weather Service Phoenix AZ
206 AM MST SUN JUL 3 2016
.SYNOPSIS...
Subtle drying transitioning in from the west will relegate the best
chances for afternoon and evening storms Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes drier.
Dry and warm conditions will last through much of next week, save for
a period in the mid-week where a slight increase in humidities
return. Further drying from the west is possible into next weekend
with near average temperatures and mostly clear skies.
&&
.DISCUSSION...
Building anticyclonic heights noted over the region both in the
evening RAOBs as well as long-framed regional radar loops, with
returns almost oriented on a northward moving concave arc from
Barstow, CA through the AZ White Mountains. Westerly mean and UL
flow has returned, with storm tops quickly being lofted
northeastward on this evening`s stronger storms. The SE CA and AZ
Lower Deserts will be in for several quiet days as several strong
Pacific troughs transition through the West Coast and Intermountain
West. Water vapor imagery overnight depicts three such trough
circulations landfalling or moving towards the West Coast. The
southern most is significantly dry through the mid and upper levels
over the L.A. Basin. Unseasonably strong westerly flow noted 500mb
and above, with a 50-55kt 300mb jet skirting across northern AZ later
tonight and into Monday, tied to the southern most shortwave. Loss of
our moisture advecting wind profile will allow for some thinning of
PWATs and LL dewpoints with daytime mixing, drawing them out of the
MMB richness. Resulting PoP forecasts save for some lingering PoPs on
the Rim for today, are well below climo and have nil chances for the
lower deserts and non-zero but still non-weather mentionable values
for the Zone 24/Southern Gila mountains. Under clear skies and fairly
typical winds, temperatures will settle out within range of early
July normals, 107F for Phoenix and Yuma both today and Monday. Subtle
variances in 1000-500mb thicknesses and a peak of 850mb temperatures
on Tuesday could support temperatures near 110F for the warmer
deserts, likely the warmest day but staying below excessive heat
thresholds.
More noticeable spread enters the temperature forecasts for Wednesday
and beyond, especially the morning lows, tied to the depth and
persistence of a mid-week moisture intrusion from the south. Up until
this point, the ML/UL high centers remained to our southeast over
Mexico. GFS model trends with the intrusion have been a bit drier the
last few nights, while the ECMWF remains a higher on the 850mb Td
fields for Wednesday and Thursday. Forecast streamlines through the
column struggle to take up anything with an easterly influence, with
850-700mb winds turning southerly for 24 hr window or so. While it`s
still a ways out...ample moisture over the Sierra Madre and inverted
wave movement along the Mexican Riviera and Baja Peninsula could
trigger some larger storm complexes that send outflow intrusions
northward, rather than our depending on easterly to southeasterly
advection flow. Resulting temperatures forecasts are rather steady
state and near seasonal normals, but any moisture insulation could
shave a few degrees off the limits on the diurnal range, more likely
for locations east of the CO River Valley. Slight storm chances enter
into SE AZ, the White Mtns and the Rim for Wednesday and some of the
mountainous locations of southern Gila county for Thursday afternoon.
With still modest westerly flow progged through the majority of the
column, conditions are not looking favorable for outflow intrusions
to make their way onto the desert floors at this time. Longwave
troughing remains over the West Coast for late this week and the
coming weekend with the potential for further dry advection from the
west. Zonal heights aloft over the Southwest should result in near
average temperatures, dry conditions for nearly all forecast locales
under mostly clear skies.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
A drier and more stable atmosphere is forecast to move into the
greater Phoenix area through Sunday evening. Therefore mostly clear
skies are forecast. Surface winds will be light easterly, becoming
west during the afternoons and evening generally under 10 knots.
Southeast California/Southwest Arizona including KIPL and KBLH:
A drier and more stable atmosphere is forecast to move into
the greater Phoenix area through Sunday evening. Mostly clear skies
are forecast, with steady south winds 8 to 15 knots.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Southwesterly flow between the monsoon high across northern Mexico
and low pressure across the Pacific Northwest will result in above
normal temperatures and generally dry conditions. An increase in
moisture is expected Wednesday as the high shifts eastward. Drier
westerly flow across southeastern California will then battle deeper
moisture across southeastern Arizona through the remainder of the
week, with showers and thunderstorms mainly relegated to southern and
eastern Arizona. Near normal temperatures are expected mid to late
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...Nolte
AVIATION...Vasquez
FIRE WEATHER...Hirsch
[top]
Area Forecast Discussion
National Weather Service Tucson AZ
200 AM MST SUN JUL 3 2016
.SYNOPSIS...Drier air moving into the region will significantly
reduce the amount of thunderstorms through Tuesday. The lack of
showers and cloud cover will allow for higher afternoon temperatures
as well. An increase in moisture the middle of next week will
increase the chances of showers and thunderstorms once again.
&&
.DISCUSSION...Water vapor imagery and 03/00Z upper-air plots show
nearly zonal flow across the Desert Southwest as Arizona lies
between high pressure over southern Chihuahua Mexico and a low
pressure system over central California. Plenty of dry mid level air
across the eastern Pacific waters and extending across northern
Baja, northwest Sonora Mexico and the southern two thirds of Arizona
and into New Mexico. The 03/00Z KTWC sounding showed significant
drying in the past 48 hours or so, with a PW of 1.2 inches compared
to 1.77 inches from Thursday afternoon. The 06Z GPS PW values from
the U of A indicate around 1.2 inches and the CIRA LPW total
indicates 1.1 inches. IR satellite imagery shows mostly clear skies
across much of Arizona at this time, with the exception being some
mid level clouds over eastern Sonora and northwest Chihuahua that
have spilled over into extreme southern Cochise county and parts
of Santa Cruz county.
As of 08Z (1 AM MST), temperatures ranged from the lower 70s to the
lower 80s which are generally around 5 to 8 degs warmer than 24
hours ago. Dewpoint temperatures range from the lower 50s to the mid
60s and these values range from 1 to 5 degs cooler/drier than 24
hours ago. As a result, relative humidity values range from 15 to 30
percent drier than this time yesterday.
Models indicate that the ridge to our south and west will build a
bit farther north and east today, becoming nearly overhead. This
will result in warmer afternoon temperatures through Tuesday as the
high remains in the same general area through that time. In
addition, expect a reduction in the threat for showers and
thunderstorms as well. Limited activity may occur today and Monday,
mostly over the White mountains and perhaps isolated activity over
southern parts of Cochise county on Tuesday. By Tuesday night into
Wednesday models indicate that return flow on the western flank of
the ridge will allow for an increase in moisture with PW`s generally
ranging from around 0.75-1.0 inches through Tuesday before climbing
back up to around 1.0-1.3 inches through early Thursday. Values will
then decrease again late in the week and into the weekend as drier
air gets ushered in from the west in response to an approaching
trough well to our northwest and north. This will once again result
in increasing daytime temperatures after a brief respite on
Wednesday and Thursday due to increasing moisture and the threat of
convection moderating temperatures a bit.
For Tucson, high temperatures will range from 2 to 4 degs below
normal today, then will hover within a degree or two either side of
normal for Monday through Friday. For next weekend, highs a few
degrees above normal. Low temperatures will range from 2 to 5 degs
above normal each morning, although the warmest mornings will occur
Wednesday and Thursday.
&&
.AVIATION...VALID THRU 04/12Z.
High pressure building in from west to east will bring more stable
conditions and mostly clear skies. Winds will generally be less than
10 kts through the period. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Drying trend is expected to start the new
week with little if any convection today through Tuesday. A brief
surge of moisture will bring some scattered showers and
thunderstorms Wednesday into Friday then we will dry out once again.
Winds will generally favor diurnal patterns, with some enhancement
in areas where afternoon northwest flow is the norm. Portions of
zone 152 could see afternoon gustiness greater than 20 mph in valley
locations Sunday through Tuesday.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
PUBLIC...Mollere
AVIATION/FIRE WEATHER...Cerniglia
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
[top]
Area Forecast Discussion
National Weather Service Flagstaff AZ
921 PM MST SAT JUL 2 2016
.SYNOPSIS...Sunday, drier westerly flow across Arizona will
bring drier and warmer conditions to the area heading into next
week.
&&
.DISCUSSION...The forecast was updated for the overnight time
period. The chance of precipitation was lowered to only isolated
showers and thunderstorms over southern Navajo and Apache counties
through midnight...then mainly dry after midnight.
&&
.PREV DISCUSSION /340 PM MST/...A somewhat linear convective
feature formed this afternoon along a convergence zone formed in
the wake of last nights outflow and a developing s/wv ridge to our
west. This feature is nearly aligned along the I-40 corridor,
which is problematic for travelers this afternoon.
After this evening, drier mid-level air and anticyclonic flow is
evident to our west on water vapor imagery. Additionally, warmer
temperatures aloft will develop through at least Monday with this
s/wv ridge.
At the same time, long wave troughing develops over the northwest
United States, providing a prolonged period of drier and stable
flow over the southwest. A brief intrusion of monsoon moisture may
return Wednesday or Thursday, but then right back to dry
westerlies heading into next weekend.
The net result is a period of mainly dry and warmer conditions
after today.
&&
.AVIATION...For the 06Z Package...Expect VFR conditions with a few
showers and thunderstorms on Sunday after 18Z mainly over the
mountain areas of the Mogollon Rim and Chuska Mountains. Shower
activity will diminish around 02Z. Aviation discussion not updated
for TAF amendments.
&&
.FIRE WEATHER...A drier and more stable westerly flow will bring
decreasing shower and thunderstorm coverage to northern Arizona.
Storm motion on Sunday will be from the west to the east.
Tuesday through thursday...Only daytime and isolated storms are
expected across ponderosa forests through the period as dry westerly
flow increases across the area. Elsewhere very dry with afternoon
minimum humidities belwo 15 percent.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...TC/Peterson
AVIATION...Bohlin
FIRE WEATHER...DL
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Phoenix AZ
830 PM MST SAT JUL 2 2016
.SYNOPSIS...
Subtle drying, transitioning in from the west will relegate the best
chances for afternoon and evening storms Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes
drier. Dry and warm conditions will last through much of next week,
save for a period in the mid-week where a slight increase in
humidities return.
&&
.DISCUSSION...
Anti-cyclonic mid/upper level flow, following the passing trof
yesterday/overnight stabilized the airmass in our forecast area
today. There were no aftn tstms, only stable cumulus clouds.
Additionally, upper air data showed the airmass had dried noticeably
from the west today, with the monsoon moisture boundary now
pushed into southeast AZ.
Anti-cyclonic winds aloft tomorrow and Monday, with unseasonably
warm mid level temperatures and additional moisture loss, should
provide dry and warmer weather over most of the forecast area.
Current dry and warmer forecasts look good. no updates planned.
.PREVIOUS DISCUSSION...135 PM MST...
Slightly drier and more anticyclonic flow aloft continued to spread
into central Arizona from the west early this afternoon in the wake
of a departing upper trof pushing east and into western New Mexico.
Surface dewpoints at 1 PM were still elevated and mostly ranged from
the mid 50s to low 60s, although they were trending downward and
were running 2 to 9 degrees lower than 24 hours ago. Despite
elevated moisture, the threat for thunderstorms this afternoon will
pretty much be confined to higher terrain areas east of Phoenix;
upper streamlines this afternoon will be slightly anticyclonic and
laminar with no significant deformation/difluence. With minimal upper
support we can expect some cumulus over the deserts - and we can see
that developing already on visible imagery - but that will be about
it convectively speaking. Early afternoon SPC mesoanalysis graphics
depicted CAPE over 1000 j/kg over the central deserts, but there was
a marked drying trend forecast with CAPE dropping noticeably from the
west as the afternoon progresses.
More prominent westerly flow aloft will develop as the ML/UL high
centers remain to our southeast over Mexico on Sunday through early
next week. Temperatures will gradually warm and return to normal
through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and
a return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
A drier and more stable atmosphere is forecast to move into the
greater Phoenix area through Sunday evening. Therefore mostly clear
skies are forecast. Surface winds will be light easterly, becoming
west during the afternoons and evening generally under 10 knots.
Southeast California/Southwest Arizona including KIPL and KBLH:
A drier and more stable atmosphere is forecast to move into
the greater Phoenix area through Sunday evening. Mostly clear skies
are forecast, with steady south winds 8 to 15 knots.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Southwesterly flow between the monsoon high across northern Mexico
and low pressure across the Pacific Northwest will result in above
normal temperatures and generally dry conditions. An increase in
moisture is expected Wednesday as the high shifts eastward. Drier
westerly flow across southeastern California will then battle deeper
moisture across southeastern Arizona through the remainder of the
week, with showers and thunderstorms mainly relegated to southern and
eastern Arizona. Near normal temperatures are expected mid to late
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/CB/Nolte
AVIATION...Vasquez
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Tucson AZ
821 PM MST SAT JUL 2 2016
.SYNOPSIS...Drier air moving into the region will significantly
reduce the amount of convection through Monday. The lack of showers
and cloud cover will allow for higher afternoon temperatures as
well. An increase in moisture the middle of next week will increase
the chances of showers and thunderstorms once again.
&&
.DISCUSSION...We have dried quite a bit in the past 36 hours,
with precipitable water values down to around 1 to 1.2 inches
across the area, and surface dew points generally in the 50s
(down 6 to 12 degrees over the past 24 hours). Even with the
drying trend, good instability allowed for several strong
thunderstorms southwest through southeast of Tucson over the past
few hours. With sunset things are quieting down.
The current forecast looks good with the downward trend in storms
to start the week. As this happens, we will heat back up to near
or above typical early July averages. Please see the previous
discussion below for additional details.
&&
.AVIATION...VALID THRU 04/06Z.
High pressure building in from west to east on the back side of a
mid-level trough will bring more stable conditions to start the
new week. Winds will generally be less than 10 kts with VFR
conditions throughout. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Drying trend is expected to start the new
week. Winds will generally favor diurnal patterns, with some
enhancement in areas where afternoon northwest flow is the norm.
Portions of zone 152 could see afternoon gustiness greater than 20
mph in valley locations Sunday through Tuesday.
&&
.PREV DISCUSSION...The drying trend will continue Sunday and
Monday as the ridge of high pressure aloft over Sonora and
Chihuahua shunts the deep moisture to our south and east with most
areas remaining dry. About the best we can hope for is a slight
chance of showers and thunderstorms mainly across the White
Mountains both days with the rest of the forecast area remaining
dry. Given the drier atmosphere, temperatures will will warm back
up to normal values by Monday and Tuesday. The ridge axis will be
far enough east on Tuesday to start a southerly flow of moisture
into far southeast Arizona. Thus, slight chances for showers and
thunderstorms are possible for the higher terrain and
international border area across Cochise County. The northward
push of moisture over the rest of the region is expected Wednesday
and Thursday with a more typical early July monsoon pattern then
before drier westerly flow returns for the end of the work week
and into next weekend as the mid/upper high pushes south of the
area again.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Meyer/Lader/Cantin
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Flagstaff AZ
340 PM MST SAT JUL 02 2016
.SYNOPSIS...Expect active monsoon weather into this evening. By
Sunday, drier westerly flow across Arizona will bring drier and
warmer conditions to the area heading into next week.
&&
.DISCUSSION...A somewhat linear convective feature formed this
afternoon along a convergence zone formed in the wake of last nights
outflow and a developing s/wv ridge to our west. This feature is
nearly aligned along the I-40 corridor, which is problematic for
travelers this afternoon.
After this evening, drier mid-level air and anticyclonic flow is
evident to our west on water vapor imagery. Additionally, warmer
temperatures aloft will develop through at least Monday with this
s/wv ridge.
At the same time, long wave troughing develops over the northwest
United States, providing a prolonged period of drier and stable flow
over the southwest. A brief intrusion of monsoon moisture may return
Wednesday or Thursday, but then right back to dry westerlies
heading into next weekend.
The net result is a period of mainly dry and warmer conditions after
today.
&&
.AVIATION...For the 00Z Package...until 03z Sun expect scattered
shra/tsra and isold +tsra along and north of the Mogollon Rim and
isolated coverage elsewhere. Strongest storms will contain mvfr/ifr
conditions and gusty winds. Showers and thunderstorms ending aft 03z
Sun. Aft 18z Sun isolated thunderstorm coverage for areas above 6500
feet with fair wx elsewhere. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...For Sunday and Monday, a drier and more stable
westerly flow will bring decreasing shower and thunderstorm coverage
to northern Arizona. Storm motion on Sunday will be from the west to
the east.
Tuesday through thursday...Only daytime and isolated storms are
expected across ponderosa forests through the period as dry westerly
flow increases across the area. Elsewhere very dry with afternoon
minimum humidities below 15 percent.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...Peterson
AVIATION...DL
FIRE WEATHER...DL
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Tucson AZ
200 PM MST SAT JUL 2 2016
.SYNOPSIS...Drier air moving into the region will significantly
reduce the amount of convection through Monday. The lack of showers
and cloud cover will allow for higher afternoon temperatures as
well. An increase in moisture the middle of next week will increase
the chances of showers and thunderstorms once again.
&&
.DISCUSSION...The atmosphere is starting to dry out with GPS pwat
values down to 1 inch to 1.25 inches across southeast Arizona as
ridging builds in and drier air aloft is mixing down. There were a
few showers and thunderstorms briefly this morning that formed along
the higher terrain southeast of Tucson but those quickly faded away
as they moved off the mountains with just a few light showers
redeveloping in the last half hour. One shower did pass over Sierra
Vista with one gauge recorded a half inch this morning. Have trended
pops downward this afternoon but will still depict a slight chance
of a shower or thunderstorm south and east of Tucson into early this
evening.
The drying trend will continue Sunday and Monday as the ridge of
high pressure aloft over Sonora and Chihuahua shunts the deep
moisture to our south and east with most areas remaining dry. About
the best we can hope for is a slight chance of showers and
thunderstorms mainly across the White Mountains both days with the
rest of the forecast area remaining dry. Given the drier atmosphere,
temperatures will will warm back up to normal values by Monday and
Tuesday. The ridge axis will be far enough east on Tuesday to start
a southerly flow of moisture into far southeast Arizona. Thus,
slight chances for showers and thunderstorms are possible for the
higher terrain and international border area across Cochise County.
The northward push of moisture over the rest of the region is
expected Wednesday and Thursday with a more typical early July
monsoon pattern then before drier westerly flow returns for the end
of the work week and into next weekend as the mid/upper high pushes
south of the area again.
&&
.AVIATION...VALID THRU 04/00Z.
High pressure building in from west to east on the back side of a
mid-level trough will bring stable conditions this afternoon into
early next week. Winds will generally be less than 10 kts with VFR
conditions throughout. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Drying trend is expected through early next week.
Winds will generally favor diurnal patterns, with some enhancement
in areas where afternoon northwest flow is the norm. Portions of
zone 152 could see afternoon gustiness greater than 20 mph in valley
locations Sunday through Tuesday.
&&
.TWC Watches/Warnings/Advisories...None.
&&
$$
Public...GL
Aviation/Fire Weather...Cantin
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Phoenix AZ
135 PM MST SAT JUL 2 2016
.SYNOPSIS...
A combination of lingering monsoon moisture and weather disturbances
moving eastward across the Desert Southwest will bring chances for
showers and thunderstorms through this evening over higher terrain
areas east of Phoenix. Subtle drying transitioning in from the west
will relegate the best chances for afternoon and evening storms
Sunday over the higher terrain of eastern Arizona, mainly east of
Globe. High temperatures will steadily climb into the weekend and
early next week as the atmosphere becomes drier. Dry and warm
conditions will last through much of next week, save for a period in
the mid-week where a slight increase in humidities return.
&&
.DISCUSSION...
Slightly drier and more anticyclonic flow aloft continued to spread
into central Arizona from the west early this afternoon in the wake
of a departing upper trof pushing east and into western New Mexico.
Surface dewpoints at 1 PM were still elevated and mostly ranged from
the mid 50s to low 60s, although they were trending downward and
were running 2 to 9 degrees lower than 24 hours ago. Despite
elevated moisture, the threat for thunderstorms this afternoon will
pretty much be confined to higher terrain areas east of Phoenix;
upper streamlines this afternoon will be slightly anticyclonic and
laminar with no significant deformation/difluence. With minimal upper
support we can expect some cumulus over the deserts - and we can see
that developing already on visible imagery - but that will be about
it convectively speaking. Early afternoon SPC mesoanalysis graphics
depicted CAPE over 1000 j/kg over the central deserts, but there was
a marked drying trend forecast with CAPE dropping noticeably from the
west as the afternoon progresses.
More prominent westerly flow aloft will develop as the ML/UL high
centers remain to our southeast over Mexico on Sunday through early
next week. Temperatures will gradually warm and return to normal
through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and
a return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No thunderstorms are forecast for the greater Phoenix area today,
but mountain thunderstorms to the east are still expected, especially
this afternoon. Wind speeds of 12 kts or less and fairly typical diurnal
switches are likely. Very slim chance of any outflows from mountain
storms to affect area terminals.
Southeast California/Southwest Arizona including KIPL and KBLH:
Generally clear skies through Sunday. Winds will be breezy during the
afternoon at KBLH following consistent southerly directions. Wind
speeds at KIPL will mostly fall between 8-12 kts with southeasterly
directions until early this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Southwesterly flow between the monsoon high across northern Mexico
and low pressure across the Pacific Northwest will result in above
normal temperatures and generally dry conditions. An increase in
moisture is expected Wednesday as the high shifts eastward. Drier
westerly flow across southeastern California will then battle deeper
moisture across southeastern Arizona through the remainder of the
week, with showers and thunderstorms mainly relegated to southern and
eastern Arizona. Near normal temperatures are expected mid to late
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...CB/Nolte
AVIATION...Kuhlman
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Phoenix AZ
135 PM MST SAT JUL 2 2016
.SYNOPSIS...
A combination of lingering monsoon moisture and weather disturbances
moving eastward across the Desert Southwest will bring chances for
showers and thunderstorms through this evening over higher terrain
areas east of Phoenix. Subtle drying transitioning in from the west
will relegate the best chances for afternoon and evening storms
Sunday over the higher terrain of eastern Arizona, mainly east of
Globe. High temperatures will steadily climb into the weekend and
early next week as the atmosphere becomes drier. Dry and warm
conditions will last through much of next week, save for a period in
the mid-week where a slight increase in humidities return.
&&
.DISCUSSION...
Slightly drier and more anticyclonic flow aloft continued to spread
into central Arizona from the west early this afternoon in the wake
of a departing upper trof pushing east and into western New Mexico.
Surface dewpoints at 1 PM were still elevated and mostly ranged from
the mid 50s to low 60s, although they were trending downward and
were running 2 to 9 degrees lower than 24 hours ago. Despite
elevated moisture, the threat for thunderstorms this afternoon will
pretty much be confined to higher terrain areas east of Phoenix;
upper streamlines this afternoon will be slightly anticyclonic and
laminar with no significant deformation/difluence. With minimal upper
support we can expect some cumulus over the deserts - and we can see
that developing already on visible imagery - but that will be about
it convectively speaking. Early afternoon SPC mesoanalysis graphics
depicted CAPE over 1000 j/kg over the central deserts, but there was
a marked drying trend forecast with CAPE dropping noticeably from the
west as the afternoon progresses.
More prominent westerly flow aloft will develop as the ML/UL high
centers remain to our southeast over Mexico on Sunday through early
next week. Temperatures will gradually warm and return to normal
through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and
a return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No thunderstorms are forecast for the greater Phoenix area today,
but mountain thunderstorms to the east are still expected, especially
this afternoon. Wind speeds of 12 kts or less and fairly typical diurnal
switches are likely. Very slim chance of any outflows from mountain
storms to affect area terminals.
Southeast California/Southwest Arizona including KIPL and KBLH:
Generally clear skies through Sunday. Winds will be breezy during the
afternoon at KBLH following consistent southerly directions. Wind
speeds at KIPL will mostly fall between 8-12 kts with southeasterly
directions until early this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Southwesterly flow between the monsoon high across northern Mexico
and low pressure across the Pacific Northwest will result in above
normal temperatures and generally dry conditions. An increase in
moisture is expected Wednesday as the high shifts eastward. Drier
westerly flow across southeastern California will then battle deeper
moisture across southeastern Arizona through the remainder of the
week, with showers and thunderstorms mainly relegated to southern and
eastern Arizona. Near normal temperatures are expected mid to late
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...CB/Nolte
AVIATION...Kuhlman
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Phoenix AZ
1249 PM MST SAT JUL 2 2016
.UPDATE...Updated Fire Weather Discussion.
&&
.SYNOPSIS...
A combination of lingering monsoon moisture and weather disturbances
moving eastward across the Desert Southwest will bring chances for
showers and thunderstorms early today from Phoenix eastward. Subtle
drying transitioning in from the west will relegate the best chances
for afternoon and evening storms today and Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes drier.
Dry and warm conditions will last through much of next week, save for
a period in the mid-week where a slight increase in humidities return.
&&
.DISCUSSION...
At 9 am this morning, MCS associated with a passing short wave
continued to dissipate as it passed by to the northeast of Phoenix,
mostly grazing the border of our far eastern CWA as a few
showers/storms moved past Roosevelt and to the north of Globe. IR
imagery showed sunny skies from Phoenix west, and the 12z 500mb plot
indicated pronounced anticyclonic curvature over western AZ/SERN CA
behind the exiting trof. Of course, low level moisture over south
central AZ remains elevated this morning, with 1.57 inches of PWAT
at Phoenix and central desert dewpoints in the upper 50s to mid 60s.
However, we look to be moving into a drying phase of the monsoon
starting today and heading into the first part of next week as
westerly flow aloft and deeper westerly steering flow looks to
dominate the weather pattern for Arizona. For the rest of today we
should see mostly sunny skies west of Phoenix with some afternoon
cumulus in the area, and we will see a continued chance of afternoon
storms over the higher terrain northeast of Phoenix, although any
storm that forms will head off quickly towards the east/northeast.
Rain chances in the Phoenix area will be slim this afternoon, around
10 percent at best and most areas mostly likely will not see any
convection. West/southwest steering flow is always very detrimental
to storm chances in the greater Phoenix area and with ridging moving
in from the west, chances are even slimmer than normal. Current
forecasts look to be in good shape.
.PREVIOUS DISCUSSION...
Monsoon 2016 is off to an interesting start. Outside of our
exceptional heat events typical of this time of year (which
themselves produced rare upper teen to 120F values at some locales),
an earlier-than-climatologically-usual onset of the MMB intrusion,
record-breaking late June PWAT values, dewpoints and cloudiness more
typical of August and an upper trough and shear profile usually seen
as a season-ending event have made for an busy season kick-off!
Cyclonic trough flow across northern and south-central AZ still
noted on model forecasts, RAOBs from earlier in the evening and a few
ACARS soundings. Satellite derived winds and ACARS soundings indicate
anticyclonic flow is beginning to transition further up through the
atmo profile over portions of the southern CO River Valley. UL
divergence and still rich Monsoonal moisture surface (PWAT axis of
values 1.5 inches or greater extends from Vegas southeastward through
portions of Maricopa County) remains, where thunderstorm activity
continues overnight and is lighting up area radar scopes. Until the
weak troughing and PVU fully exit the CWA later today, enough CAPE
lingers within the turbulent mean flow to support isolated shower and
thunderstorm activity through the early afternoon from Phoenix
eastward (also in locations that mainly missed out on Friday
afternoon`s excitement and atmo turning over). Southeast CA
observation sites have observed a steady decrease in moisture values
beginning Friday afternoon, with dewpoints running 3 to 5 degrees
drier over the last few hours compared to this time early Friday.
Upper troughing along with the cooler 500mb temperatures and storm-
supportive ML lapse rates will exit to our northeast as a more stable
upper air pattern builds in from west-southwest by this evening. LL
mixing ratios do not complete dry out and remain deep enough to
support evening precip activity over the eastern AZ mountains
Saturday and Sunday. More prominent westerly flow aloft will develop
as the ML/UL high centers remain to our southeast over Mexico through
early next week. Temperatures will gradually warm and return to
normal through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and a
return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No thunderstorms are forecast for the greater Phoenix area today,
but mountain thunderstorms to the east are still expected, especially
this afternoon. Wind speeds of 12 kts or less and fairly typical diurnal
switches are likely. Very slim chance of any outflows from mountain
storms to affect area terminals.
Southeast California/Southwest Arizona including KIPL and KBLH:
Generally clear skies through Sunday. Winds will be breezy during the
afternoon at KBLH following consistent southerly directions. Wind
speeds at KIPL will mostly fall between 8-12 kts with southeasterly
directions until early this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Southwesterly flow between the monsoon high across northern Mexico
and low pressure across the Pacific Northwest will result in above
normal temperatures and generally dry conditions. An increase in
moisture is expected Wednesday as the high shifts eastward. Drier
westerly flow across southeastern California will then battle deeper
moisture across southeastern Arizona through the remainder of the
week, with showers and thunderstorms mainly relegated to southern and
eastern Arizona. Near normal temperatures are expected mid to late
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...CB
PREVIOUS DISCUSSION...Nolte
AVIATION...Kuhlman
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Flagstaff AZ
955 AM MST SAT JUL 02 2016
.SYNOPSIS...Expect active monsoon weather again today. Starting
Sunday, drier westerly flow across Arizona will bring a downturn
in activity heading into next week.
&&
.DISCUSSION...Long lived gravity wave/outflow/decaying MCS from
Nevada last night has finally exited our eastern border. Behind
this wave, subsidence and building hghts will limit convective
development today, despite decent moisture profiles. Our current
POPs may be a little high, but they are in the ballpark.
After today, drier and stable westerly flow will take over for the
remainder of the holiday weekend and into next week. Expect fair and
seasonably warm conditions as a result.
Zones/grids look good, no updates needed.
&&
.AVIATION...For the 18Z Package...until 03z Sun expect scattered
shra/tsra and isold +tsra across northern Arizona, then decreasing
coverage. Strongest storms will contain mvfr/ifr conditions and
gusty winds. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Scattered showers and thunderstorms are expected to
persist again today, with only a few isolated storms on Sunday as
drier air filters into the area. Storm motion will be from the west
to the east.
Monday through Wednesday...Only a few isolated storms are expected
through the period over the higher terrain as dry westerly flow
develops across the area.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...Peterson
AVIATION...DL
FIRE WEATHER...JJ
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Phoenix AZ
925 AM MST SAT JUL 2 2016
.SYNOPSIS...
A combination of lingering monsoon moisture and weather disturbances
moving eastward across the Desert Southwest will bring chances for
showers and thunderstorms early today from Phoenix eastward. Subtle
drying transitioning in from the west will relegate the best chances
for afternoon and evening storms today and Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes drier.
Dry and warm conditions will last through much of next week, save for
a period in the mid-week where a slight increase in humidities return.
&&
.DISCUSSION...
At 9 am this morning, MCS associated with a passing short wave
continued to dissipate as it passed by to the northeast of Phoenix,
mostly grazing the border of our far eastern CWA as a few
showers/storms moved past Roosevelt and to the north of Globe. IR
imagery showed sunny skies from Phoenix west, and the 12z 500mb plot
indicated pronounced anticyclonic curvature over western AZ/SERN CA
behind the exiting trof. Of course, low level moisture over south
central AZ remains elevated this morning, with 1.57 inches of PWAT
at Phoenix and central desert dewpoints in the upper 50s to mid 60s.
However, we look to be moving into a drying phase of the monsoon
starting today and heading into the first part of next week as
westerly flow aloft and deeper westerly steering flow looks to
dominate the weather pattern for Arizona. For the rest of today we
should see mostly sunny skies west of Phoenix with some afternoon
cumulus in the area, and we will see a continued chance of afternoon
storms over the higher terrain northeast of Phoenix, although any
storm that forms will head off quickly towards the east/northeast.
Rain chances in the Phoenix area will be slim this afternoon, around
10 percent at best and most areas mostly likely will not see any
convection. West/southwest steering flow is always very detrimental
to storm chances in the greater Phoenix area and with ridging moving
in from the west, chances are even slimmer than normal. Current
forecasts look to be in good shape.
.PREVIOUS DISCUSSION...
Monsoon 2016 is off to an interesting start. Outside of our
exceptional heat events typical of this time of year (which
themselves produced rare upper teen to 120F values at some locales),
an earlier-than-climatologically-usual onset of the MMB intrusion,
record-breaking late June PWAT values, dewpoints and cloudiness more
typical of August and an upper trough and shear profile usually seen
as a season-ending event have made for an busy season kick-off!
Cyclonic trough flow across northern and south-central AZ still
noted on model forecasts, RAOBs from earlier in the evening and a few
ACARS soundings. Satellite derived winds and ACARS soundings indicate
anticyclonic flow is beginning to transition further up through the
atmo profile over portions of the southern CO River Valley. UL
divergence and still rich Monsoonal moisture surface (PWAT axis of
values 1.5 inches or greater extends from Vegas southeastward through
portions of Maricopa County) remains, where thunderstorm activity
continues overnight and is lighting up area radar scopes. Until the
weak troughing and PVU fully exit the CWA later today, enough CAPE
lingers within the turbulent mean flow to support isolated shower and
thunderstorm activity through the early afternoon from Phoenix
eastward (also in locations that mainly missed out on Friday
afternoon`s excitement and atmo turning over). Southeast CA
observation sites have observed a steady decrease in moisture values
beginning Friday afternoon, with dewpoints running 3 to 5 degrees
drier over the last few hours compared to this time early Friday.
Upper troughing along with the cooler 500mb temperatures and storm-
supportive ML lapse rates will exit to our northeast as a more stable
upper air pattern builds in from west-southwest by this evening. LL
mixing ratios do not complete dry out and remain deep enough to
support evening precip activity over the eastern AZ mountains
Saturday and Sunday. More prominent westerly flow aloft will develop
as the ML/UL high centers remain to our southeast over Mexico through
early next week. Temperatures will gradually warm and return to
normal through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and a
return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No thunderstorms are forecast for the greater Phoenix area today,
but mountain thunderstorms to the east are still expected, especially
this afternoon. Wind speeds of 12 kts or less and fairly typical diurnal
switches are likely. Very slim chance of any outflows from mountain
storms to affect area terminals.
Southeast California/Southwest Arizona including KIPL and KBLH:
Generally clear skies through Sunday. Winds will be breezy during the
afternoon at KBLH following consistent southerly directions. Wind
speeds at KIPL will mostly fall between 8-12 kts with southeasterly
directions until early this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Monday through Friday: The monsoon high will rebuild across
southeastern Arizona Monday, resulting in above normal temperatures
and generally dry conditions. An increase in moisture is expected
Wednesday as the high shifts eastward. Drier westerly flow across
southeastern California will battle deeper moisture across
southeastern Arizona through the remainder of the week, with showers
and thunderstorms mainly relegated to southern and eastern Arizona.
Near normal temperatures are expected mid to late 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...CB
PREVIOUS DISCUSSION...Nolte
AVIATION...Kuhlman
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Phoenix AZ
925 AM MST SAT JUL 2 2016
.SYNOPSIS...
A combination of lingering monsoon moisture and weather disturbances
moving eastward across the Desert Southwest will bring chances for
showers and thunderstorms early today from Phoenix eastward. Subtle
drying transitioning in from the west will relegate the best chances
for afternoon and evening storms today and Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes drier.
Dry and warm conditions will last through much of next week, save for
a period in the mid-week where a slight increase in humidities return.
&&
.DISCUSSION...
At 9 am this morning, MCS associated with a passing short wave
continued to dissipate as it passed by to the northeast of Phoenix,
mostly grazing the border of our far eastern CWA as a few
showers/storms moved past Roosevelt and to the north of Globe. IR
imagery showed sunny skies from Phoenix west, and the 12z 500mb plot
indicated pronounced anticyclonic curvature over western AZ/SERN CA
behind the exiting trof. Of course, low level moisture over south
central AZ remains elevated this morning, with 1.57 inches of PWAT
at Phoenix and central desert dewpoints in the upper 50s to mid 60s.
However, we look to be moving into a drying phase of the monsoon
starting today and heading into the first part of next week as
westerly flow aloft and deeper westerly steering flow looks to
dominate the weather pattern for Arizona. For the rest of today we
should see mostly sunny skies west of Phoenix with some afternoon
cumulus in the area, and we will see a continued chance of afternoon
storms over the higher terrain northeast of Phoenix, although any
storm that forms will head off quickly towards the east/northeast.
Rain chances in the Phoenix area will be slim this afternoon, around
10 percent at best and most areas mostly likely will not see any
convection. West/southwest steering flow is always very detrimental
to storm chances in the greater Phoenix area and with ridging moving
in from the west, chances are even slimmer than normal. Current
forecasts look to be in good shape.
.PREVIOUS DISCUSSION...
Monsoon 2016 is off to an interesting start. Outside of our
exceptional heat events typical of this time of year (which
themselves produced rare upper teen to 120F values at some locales),
an earlier-than-climatologically-usual onset of the MMB intrusion,
record-breaking late June PWAT values, dewpoints and cloudiness more
typical of August and an upper trough and shear profile usually seen
as a season-ending event have made for an busy season kick-off!
Cyclonic trough flow across northern and south-central AZ still
noted on model forecasts, RAOBs from earlier in the evening and a few
ACARS soundings. Satellite derived winds and ACARS soundings indicate
anticyclonic flow is beginning to transition further up through the
atmo profile over portions of the southern CO River Valley. UL
divergence and still rich Monsoonal moisture surface (PWAT axis of
values 1.5 inches or greater extends from Vegas southeastward through
portions of Maricopa County) remains, where thunderstorm activity
continues overnight and is lighting up area radar scopes. Until the
weak troughing and PVU fully exit the CWA later today, enough CAPE
lingers within the turbulent mean flow to support isolated shower and
thunderstorm activity through the early afternoon from Phoenix
eastward (also in locations that mainly missed out on Friday
afternoon`s excitement and atmo turning over). Southeast CA
observation sites have observed a steady decrease in moisture values
beginning Friday afternoon, with dewpoints running 3 to 5 degrees
drier over the last few hours compared to this time early Friday.
Upper troughing along with the cooler 500mb temperatures and storm-
supportive ML lapse rates will exit to our northeast as a more stable
upper air pattern builds in from west-southwest by this evening. LL
mixing ratios do not complete dry out and remain deep enough to
support evening precip activity over the eastern AZ mountains
Saturday and Sunday. More prominent westerly flow aloft will develop
as the ML/UL high centers remain to our southeast over Mexico through
early next week. Temperatures will gradually warm and return to
normal through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and a
return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No thunderstorms are forecast for the greater Phoenix area today,
but mountain thunderstorms to the east are still expected, especially
this afternoon. Wind speeds of 12 kts or less and fairly typical diurnal
switches are likely. Very slim chance of any outflows from mountain
storms to affect area terminals.
Southeast California/Southwest Arizona including KIPL and KBLH:
Generally clear skies through Sunday. Winds will be breezy during the
afternoon at KBLH following consistent southerly directions. Wind
speeds at KIPL will mostly fall between 8-12 kts with southeasterly
directions until early this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Monday through Friday: The monsoon high will rebuild across
southeastern Arizona Monday, resulting in above normal temperatures
and generally dry conditions. An increase in moisture is expected
Wednesday as the high shifts eastward. Drier westerly flow across
southeastern California will battle deeper moisture across
southeastern Arizona through the remainder of the week, with showers
and thunderstorms mainly relegated to southern and eastern Arizona.
Near normal temperatures are expected mid to late 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...CB
PREVIOUS DISCUSSION...Nolte
AVIATION...Kuhlman
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Tucson AZ
817 AM MST SAT JUL 2 2016
.SYNOPSIS...Drier air moving into the region will significantly
reduce the amount of convection expected today with little if any
expected Sunday and Monday. The lack of showers and cloud cover will
allow for higher afternoon temperatures as well. An increase in
moisture the middle of next week will increase the chances of showers
and thunderstorms once again.
&&
.DISCUSSION...Latest IR/WV imagery shows mostly clear skies from
Tucson south and westward with partly to mostly cloudy skies north
and east of Tucson. A few showers and thunderstorms are now
occurring over the Upper Gila River Valley near Safford but these
are gradually weakening. Meanwhile, a weakening forward propagating
MCS over north/central Arizona continues to move towards the White
Mountains this morning which may result in a few thunderstorms
across northern Graham and Greenlee counties later this morning. For
the rest of the area, the mid and upper levels have dried out
considerably but boundary layer moisture remains adequate with PWAT
values of 1.25 to 1.5 inches. Latest HRRR runs and UofA WRF NAM/GFS
show just enough boundary layer moisture for isolated to scattered
thunderstorms from the Tucson area south and eastward today. With
ridging building in, the storms should generally struggle so we
aren`t expecting significant impacts, but brief heavy rain is
possible.
The drying trend will continue Sunday and Monday as the ridge of
high pressure aloft over Sonora shunts the deep moisture to our
south and east with most areas remaining dry and otherwise just a
slight chance of showers and thunderstorms mainly across the White
Mountains. With ridging building in, temperatures will warm back up
to near normal values by Monday and Tuesday. The ridge axis will be
far enough east on Tuesday to start a southerly flow of moisture
into southeast Arizona. Thus, slight chances for showers and
thunderstorms are possible for the higher terrain and international
border then. The northward push of moisture over the rest of the
region is expected Wednesday and Thursday with a more typical early
July monsoon pattern then before drier westerly flow returns for the
end of the work week and into next weekend.
&&
.AVIATION...VALID THRU 03/18Z.
Considerably fewer showers and thunderstorms today, mainly for areas
south and east of Tucson. Mostly clear skies this morning for the
terminals, but during the afternoon hours, ceilings generally 10-15K
ft. Gusty winds and brief MVFR conditions in heavy rainfall are
likely near storms where wind gusts could exceed 30 kts. Otherwise
surface winds generally 10 kts or less. Aviation discussion not
updated for TAF amendments.
&&
.FIRE WEATHER...Moisture will begin to diminish across the region
beginning today and continuing through Tuesday, resulting in a
decrease in the coverage of showers and thunderstorms and a slight
bump up in afternoon temperatures. Some moisture will begin to
return to the area Wednesday for a general increase in showers and
thunderstorms once again.
&&
.TWC Watches/Warnings/Advisories...None.
&&
$$
GL
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Tucson AZ
832 AM MST SUN JUL 3 2016
.SYNOPSIS...Drier air moving into the region will significantly
reduce the amount of thunderstorms through Tuesday. The lack of
showers and cloud cover will allow for higher afternoon temperatures
as well. An increase in moisture the middle of next week will
increase the chances of showers and thunderstorms once again.
&&
.DISCUSSION...Latest wv imagery and upper air plots indicate mid and
upper level ridging just to our south with generally westerly flow
aloft. Still some decent moisture in the boundary layer below about
650 mb and very dry above. Precipitable water off the 12z KTWC
sounding came in at 1.26 inches. As boundary layer moisture
continues to decrease, moisture will be very limited to generate
showers and thunderstorms this afternoon but can`t rule out slight
chances in the higher terrain over Cochise and Santa Cruz counties
along with the White Mountains. It will be even more of a struggle
Monday and Tuesday to get much more than some cumulus build-ups in
these same higher terrain areas with high pressure aloft centered
just to our south east. With the drier air, temperatures will be
near seasonal normals the next few days.
By Wednesday and Thursday a return flow of moisture around the high
pressure which will then be located near the Big Bend of Texas will
bring chances of showers and thunderstorms back to much of Southeast
Arizona. However, this will be short lived as westerly flow aloft
returns by Friday and continues next weekend with a drier pattern
returning. Expect a few degrees of cooling Wednesday through Friday
then warming back up next weekend.
&&
.AVIATION...VALID THRU 04/18Z.
High pressure building in from west to east will bring more stable
conditions and mostly clear skies. Winds will generally be less than
10 kts through the period. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Drying trend is expected to start the new
week with little if any convection today through Tuesday. A brief
surge of moisture will bring some scattered showers and
thunderstorms Wednesday into Friday then we will dry out once again.
Winds will generally favor diurnal patterns, with some enhancement
in areas where afternoon northwest flow is the norm. Portions of
zone 152 could see afternoon gustiness greater than 20 mph in valley
locations Sunday through Tuesday.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
GL
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
[top]
Area Forecast Discussion
National Weather Service Phoenix AZ
815 AM MST SUN JUL 3 2016
.SYNOPSIS...
Subtle drying transitioning in from the west will relegate the best
chances for afternoon and evening storms Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes drier.
Dry and warm conditions will last through much of next week, save for
a period in the mid-week where a slight increase in humidities
return. Further drying from the west is possible into next weekend
with near average temperatures and mostly clear skies.
&&
.DISCUSSION...
Early morning plot data as well as sounding data showed upper
ridging in place across Arizona with a deep profile of westerly flow
aloft through most of the atmosphere. PWAT values at Phoenix had
dropped to 1.19 inches and there was little if any CAPE present in
the sounding; additional drying in the profile will eliminate what
skinny CAPE is currently present. Surface dewpoints over the central
deserts were down 6-12 degrees from 24 hours ago and were mostly in
the mid to upper 50s at 8 am. IR imagery this morning showed
basically clear skies area-wide with just a few patches of mid cloud
forming to the southwest of Phoenix. Current SPC mesoanalysis
graphics showed just a few hundred j/kg of MLCAPE over the central
deserts and forecast over 1000 j/kg by early afternoon which seems a
bit excessive as latest NAM run only calls for aorund 300-400 j/kg
this afternoon. Given the persistent strong westerly flow aloft that
will be present this afternoon and tendency to mix down drier air to
the surface, expect that if any storms develop they will be over the
mountains to the east of Phoenix and only some aternoon cumulus will
develop over the deserts. Current forecasts have this covered and
look to be in good shape. No updates are planned attm.
.PREVIOUS DISCUSSION...
Building anticyclonic heights noted over the region both in the
evening RAOBs as well as long-framed regional radar loops, with
returns almost oriented on a northward moving concave arc from
Barstow, CA through the AZ White Mountains. Westerly mean and UL
flow has returned, with storm tops quickly being lofted
northeastward on this evening`s stronger storms. The SE CA and AZ
Lower Deserts will be in for several quiet days as several strong
Pacific troughs transition through the West Coast and Intermountain
West. Water vapor imagery overnight depicts three such trough
circulations landfalling or moving towards the West Coast. The
southern most is significantly dry through the mid and upper levels
over the L.A. Basin. Unseasonably strong westerly flow noted 500mb
and above, with a 50-55kt 300mb jet skirting across northern AZ later
tonight and into Monday, tied to the southern most shortwave. Loss of
our moisture advecting wind profile will allow for some thinning of
PWATs and LL dewpoints with daytime mixing, drawing them out of the
MMB richness. Resulting PoP forecasts save for some lingering PoPs on
the Rim for today, are well below climo and have nil chances for the
lower deserts and non-zero but still non-weather mentionable values
for the Zone 24/Southern Gila mountains. Under clear skies and fairly
typical winds, temperatures will settle out within range of early
July normals, 107F for Phoenix and Yuma both today and Monday. Subtle
variances in 1000-500mb thicknesses and a peak of 850mb temperatures
on Tuesday could support temperatures near 110F for the warmer
deserts, likely the warmest day but staying below excessive heat
thresholds.
More noticeable spread enters the temperature forecasts for Wednesday
and beyond, especially the morning lows, tied to the depth and
persistence of a mid-week moisture intrusion from the south. Up until
this point, the ML/UL high centers remained to our southeast over
Mexico. GFS model trends with the intrusion have been a bit drier the
last few nights, while the ECMWF remains a higher on the 850mb Td
fields for Wednesday and Thursday. Forecast streamlines through the
column struggle to take up anything with an easterly influence, with
850-700mb winds turning southerly for 24 hr window or so. While it`s
still a ways out, ample moisture over the Sierra Madre and inverted
wave movement along the Mexican Riviera and Baja Peninsula could
trigger some larger storm complexes that send outflow intrusions
northward, rather than our depending on easterly to southeasterly
advection flow. Resulting temperatures forecasts are rather steady
state and near seasonal normals, but any moisture insulation could
shave a few degrees off the limits on the diurnal range, more likely
for locations east of the CO River Valley. Slight storm chances enter
into SE AZ, the White Mtns and the Rim for Wednesday and some of the
mountainous locations of southern Gila county for Thursday afternoon.
With still modest westerly flow progged through the majority of the
column, conditions are not looking favorable for outflow intrusions
to make their way onto the desert floors at this time. Longwave
troughing remains over the West Coast for late this week and the
coming weekend with the potential for further dry advection from the
west. Zonal heights aloft over the Southwest should result in near
average temperatures, dry conditions for nearly all forecast locales
under mostly clear skies.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No aviation impacts through Monday morning under mostly clear skies.
Confidence is good that wind shifts/transition to an easterly
component overnight will occur later than typical, and similarly the
afternoon switch back to a westerly direction will occur earlier
than usual.
Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation impacts through Monday morning under clear skies. Sfc
winds will generally favor a south to southwest direction, though
some periods yielding a light and variable direction will be
possible towards sunrise.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Stronger than usual early July southwest flow across the region will
result in slightly above normal temperatures and generally dry
conditions. An increase in moisture Wednesday and Thursday could
lead to a few thunderstorms over higher terrain of southern Gila and
far eastern Maricopa/Pinal counties with little to no chance of
wetting rains elsewhere. With this drier pattern, afternoon minimum
humidity levels will fall back into a 10 to 20 percent range with
fair to good overnight recovery. Wind speeds will be somewhat
stronger than typical for early July with more frequent afternoon
gusts especially around higher terrain features.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...CB
PREVIOUS DISCUSSION...Nolte
AVIATION...MO
FIRE WEATHER...MO/Hirsch
Area Forecast Discussion
National Weather Service Phoenix AZ
440 AM MST SUN JUL 3 2016
...Updated Aviation and Fire Weather...
.SYNOPSIS...
Subtle drying transitioning in from the west will relegate the best
chances for afternoon and evening storms Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes drier.
Dry and warm conditions will last through much of next week, save for
a period in the mid-week where a slight increase in humidities
return. Further drying from the west is possible into next weekend
with near average temperatures and mostly clear skies.
&&
.DISCUSSION...
Building anticyclonic heights noted over the region both in the
evening RAOBs as well as long-framed regional radar loops, with
returns almost oriented on a northward moving concave arc from
Barstow, CA through the AZ White Mountains. Westerly mean and UL
flow has returned, with storm tops quickly being lofted
northeastward on this evening`s stronger storms. The SE CA and AZ
Lower Deserts will be in for several quiet days as several strong
Pacific troughs transition through the West Coast and Intermountain
West. Water vapor imagery overnight depicts three such trough
circulations landfalling or moving towards the West Coast. The
southern most is significantly dry through the mid and upper levels
over the L.A. Basin. Unseasonably strong westerly flow noted 500mb
and above, with a 50-55kt 300mb jet skirting across northern AZ later
tonight and into Monday, tied to the southern most shortwave. Loss of
our moisture advecting wind profile will allow for some thinning of
PWATs and LL dewpoints with daytime mixing, drawing them out of the
MMB richness. Resulting PoP forecasts save for some lingering PoPs on
the Rim for today, are well below climo and have nil chances for the
lower deserts and non-zero but still non-weather mentionable values
for the Zone 24/Southern Gila mountains. Under clear skies and fairly
typical winds, temperatures will settle out within range of early
July normals, 107F for Phoenix and Yuma both today and Monday. Subtle
variances in 1000-500mb thicknesses and a peak of 850mb temperatures
on Tuesday could support temperatures near 110F for the warmer
deserts, likely the warmest day but staying below excessive heat
thresholds.
More noticeable spread enters the temperature forecasts for Wednesday
and beyond, especially the morning lows, tied to the depth and
persistence of a mid-week moisture intrusion from the south. Up until
this point, the ML/UL high centers remained to our southeast over
Mexico. GFS model trends with the intrusion have been a bit drier the
last few nights, while the ECMWF remains a higher on the 850mb Td
fields for Wednesday and Thursday. Forecast streamlines through the
column struggle to take up anything with an easterly influence, with
850-700mb winds turning southerly for 24 hr window or so. While it`s
still a ways out, ample moisture over the Sierra Madre and inverted
wave movement along the Mexican Riviera and Baja Peninsula could
trigger some larger storm complexes that send outflow intrusions
northward, rather than our depending on easterly to southeasterly
advection flow. Resulting temperatures forecasts are rather steady
state and near seasonal normals, but any moisture insulation could
shave a few degrees off the limits on the diurnal range, more likely
for locations east of the CO River Valley. Slight storm chances enter
into SE AZ, the White Mtns and the Rim for Wednesday and some of the
mountainous locations of southern Gila county for Thursday afternoon.
With still modest westerly flow progged through the majority of the
column, conditions are not looking favorable for outflow intrusions
to make their way onto the desert floors at this time. Longwave
troughing remains over the West Coast for late this week and the
coming weekend with the potential for further dry advection from the
west. Zonal heights aloft over the Southwest should result in near
average temperatures, dry conditions for nearly all forecast locales
under mostly clear skies.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No aviation impacts through Monday morning under mostly clear skies.
Confidence is good that wind shifts/transition to an easterly
component overnight will occur later than typical, and similarly the
afternoon switch back to a westerly direction will occur earlier
than usual.
Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation impacts through Monday morning under clear skies. Sfc
winds will generally favor a south to southwest direction, though
some periods yielding a light and variable direction will be
possible towards sunrise.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Stronger than usual early July southwest flow across the region will
result in slightly above normal temperatures and generally dry
conditions. An increase in moisture Wednesday and Thursday could
lead to a few thunderstorms over higher terrain of southern Gila and
far eastern Maricopa/Pinal counties with little to no chance of
wetting rains elsewhere. With this drier pattern, afternoon minimum
humidity levels will fall back into a 10 to 20 percent range with
fair to good overnight recovery. Wind speeds will be somewhat
stronger than typical for early July with more frequent afternoon
gusts especially around higher terrain features.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Nolte
AVIATION...MO
FIRE WEATHER...MO/Hirsch
[top]
Area Forecast Discussion
National Weather Service Flagstaff AZ
352 AM MST SUN JUL 3 2016
.SYNOPSIS...Westerly flow across Arizona will bring drier and
warmer conditions to the area heading into next week.
&&
.DISCUSSION...
A drying westerly flow is going to take shape over the next
several days across northern Arizona. Precipitation chances will
generally be reduced to `slight` today, with chances confined to
the higher terrain of eastern AZ for Independence Day. Breezy
afternoons will take shape mid-week as well, with winds out of the
west-southwest. Warmer daytime temps can also be anticipated.
While slight chances for showers may return at times during the
coming week, the pattern looks typical for an extended monsoon
break through much of the 7-day forecast.
&&
.AVIATION...For the 12Z Package...Expect VFR conditions to prevail
over the next 24 hours. Isolated SHRA/TSRA possible 18Z-02Z
mainly over the higher terrain from Mogollon Rim and White Mtns
northward. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...A drier and more stable westerly flow will bring
decreasing shower and thunderstorm coverage to northern Arizona
today and Monday. Any isolated storms that develop today will move
from west to east.
Tuesday through Thursday...Westerly flow brings mainly dry
conditions with breezy afternoons. Temperatures near normal.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...KD
AVIATION...JJ
FIRE WEATHER...JJ
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Flagstaff AZ
352 AM MST SUN JUL 3 2016
.SYNOPSIS...Westerly flow across Arizona will bring drier and
warmer conditions to the area heading into next week.
&&
.DISCUSSION...
A drying westerly flow is going to take shape over the next
several days across northern Arizona. Precipitation chances will
generally be reduced to `slight` today, with chances confined to
the higher terrain of eastern AZ for Independence Day. Breezy
afternoons will take shape mid-week as well, with winds out of the
west-southwest. Warmer daytime temps can also be anticipated.
While slight chances for showers may return at times during the
coming week, the pattern looks typical for an extended monsoon
break through much of the 7-day forecast.
&&
.AVIATION...For the 12Z Package...Expect VFR conditions to prevail
over the next 24 hours. Isolated SHRA/TSRA possible 18Z-02Z
mainly over the higher terrain from Mogollon Rim and White Mtns
northward. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...A drier and more stable westerly flow will bring
decreasing shower and thunderstorm coverage to northern Arizona
today and Monday. Any isolated storms that develop today will move
from west to east.
Tuesday through Thursday...Westerly flow brings mainly dry
conditions with breezy afternoons. Temperatures near normal.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...KD
AVIATION...JJ
FIRE WEATHER...JJ
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Flagstaff AZ
352 AM MST SUN JUL 3 2016
.SYNOPSIS...Westerly flow across Arizona will bring drier and
warmer conditions to the area heading into next week.
&&
.DISCUSSION...
A drying westerly flow is going to take shape over the next
several days across northern Arizona. Precipitation chances will
generally be reduced to `slight` today, with chances confined to
the higher terrain of eastern AZ for Independence Day. Breezy
afternoons will take shape mid-week as well, with winds out of the
west-southwest. Warmer daytime temps can also be anticipated.
While slight chances for showers may return at times during the
coming week, the pattern looks typical for an extended monsoon
break through much of the 7-day forecast.
&&
.AVIATION...For the 12Z Package...Expect VFR conditions to prevail
over the next 24 hours. Isolated SHRA/TSRA possible 18Z-02Z
mainly over the higher terrain from Mogollon Rim and White Mtns
northward. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...A drier and more stable westerly flow will bring
decreasing shower and thunderstorm coverage to northern Arizona
today and Monday. Any isolated storms that develop today will move
from west to east.
Tuesday through Thursday...Westerly flow brings mainly dry
conditions with breezy afternoons. Temperatures near normal.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...KD
AVIATION...JJ
FIRE WEATHER...JJ
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Flagstaff AZ
352 AM MST SUN JUL 3 2016
.SYNOPSIS...Westerly flow across Arizona will bring drier and
warmer conditions to the area heading into next week.
&&
.DISCUSSION...
A drying westerly flow is going to take shape over the next
several days across northern Arizona. Precipitation chances will
generally be reduced to `slight` today, with chances confined to
the higher terrain of eastern AZ for Independence Day. Breezy
afternoons will take shape mid-week as well, with winds out of the
west-southwest. Warmer daytime temps can also be anticipated.
While slight chances for showers may return at times during the
coming week, the pattern looks typical for an extended monsoon
break through much of the 7-day forecast.
&&
.AVIATION...For the 12Z Package...Expect VFR conditions to prevail
over the next 24 hours. Isolated SHRA/TSRA possible 18Z-02Z
mainly over the higher terrain from Mogollon Rim and White Mtns
northward. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...A drier and more stable westerly flow will bring
decreasing shower and thunderstorm coverage to northern Arizona
today and Monday. Any isolated storms that develop today will move
from west to east.
Tuesday through Thursday...Westerly flow brings mainly dry
conditions with breezy afternoons. Temperatures near normal.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...KD
AVIATION...JJ
FIRE WEATHER...JJ
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Phoenix AZ
206 AM MST SUN JUL 3 2016
.SYNOPSIS...
Subtle drying transitioning in from the west will relegate the best
chances for afternoon and evening storms Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes drier.
Dry and warm conditions will last through much of next week, save for
a period in the mid-week where a slight increase in humidities
return. Further drying from the west is possible into next weekend
with near average temperatures and mostly clear skies.
&&
.DISCUSSION...
Building anticyclonic heights noted over the region both in the
evening RAOBs as well as long-framed regional radar loops, with
returns almost oriented on a northward moving concave arc from
Barstow, CA through the AZ White Mountains. Westerly mean and UL
flow has returned, with storm tops quickly being lofted
northeastward on this evening`s stronger storms. The SE CA and AZ
Lower Deserts will be in for several quiet days as several strong
Pacific troughs transition through the West Coast and Intermountain
West. Water vapor imagery overnight depicts three such trough
circulations landfalling or moving towards the West Coast. The
southern most is significantly dry through the mid and upper levels
over the L.A. Basin. Unseasonably strong westerly flow noted 500mb
and above, with a 50-55kt 300mb jet skirting across northern AZ later
tonight and into Monday, tied to the southern most shortwave. Loss of
our moisture advecting wind profile will allow for some thinning of
PWATs and LL dewpoints with daytime mixing, drawing them out of the
MMB richness. Resulting PoP forecasts save for some lingering PoPs on
the Rim for today, are well below climo and have nil chances for the
lower deserts and non-zero but still non-weather mentionable values
for the Zone 24/Southern Gila mountains. Under clear skies and fairly
typical winds, temperatures will settle out within range of early
July normals, 107F for Phoenix and Yuma both today and Monday. Subtle
variances in 1000-500mb thicknesses and a peak of 850mb temperatures
on Tuesday could support temperatures near 110F for the warmer
deserts, likely the warmest day but staying below excessive heat
thresholds.
More noticeable spread enters the temperature forecasts for Wednesday
and beyond, especially the morning lows, tied to the depth and
persistence of a mid-week moisture intrusion from the south. Up until
this point, the ML/UL high centers remained to our southeast over
Mexico. GFS model trends with the intrusion have been a bit drier the
last few nights, while the ECMWF remains a higher on the 850mb Td
fields for Wednesday and Thursday. Forecast streamlines through the
column struggle to take up anything with an easterly influence, with
850-700mb winds turning southerly for 24 hr window or so. While it`s
still a ways out...ample moisture over the Sierra Madre and inverted
wave movement along the Mexican Riviera and Baja Peninsula could
trigger some larger storm complexes that send outflow intrusions
northward, rather than our depending on easterly to southeasterly
advection flow. Resulting temperatures forecasts are rather steady
state and near seasonal normals, but any moisture insulation could
shave a few degrees off the limits on the diurnal range, more likely
for locations east of the CO River Valley. Slight storm chances enter
into SE AZ, the White Mtns and the Rim for Wednesday and some of the
mountainous locations of southern Gila county for Thursday afternoon.
With still modest westerly flow progged through the majority of the
column, conditions are not looking favorable for outflow intrusions
to make their way onto the desert floors at this time. Longwave
troughing remains over the West Coast for late this week and the
coming weekend with the potential for further dry advection from the
west. Zonal heights aloft over the Southwest should result in near
average temperatures, dry conditions for nearly all forecast locales
under mostly clear skies.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
A drier and more stable atmosphere is forecast to move into the
greater Phoenix area through Sunday evening. Therefore mostly clear
skies are forecast. Surface winds will be light easterly, becoming
west during the afternoons and evening generally under 10 knots.
Southeast California/Southwest Arizona including KIPL and KBLH:
A drier and more stable atmosphere is forecast to move into
the greater Phoenix area through Sunday evening. Mostly clear skies
are forecast, with steady south winds 8 to 15 knots.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Southwesterly flow between the monsoon high across northern Mexico
and low pressure across the Pacific Northwest will result in above
normal temperatures and generally dry conditions. An increase in
moisture is expected Wednesday as the high shifts eastward. Drier
westerly flow across southeastern California will then battle deeper
moisture across southeastern Arizona through the remainder of the
week, with showers and thunderstorms mainly relegated to southern and
eastern Arizona. Near normal temperatures are expected mid to late
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...Nolte
AVIATION...Vasquez
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Tucson AZ
200 AM MST SUN JUL 3 2016
.SYNOPSIS...Drier air moving into the region will significantly
reduce the amount of thunderstorms through Tuesday. The lack of
showers and cloud cover will allow for higher afternoon temperatures
as well. An increase in moisture the middle of next week will
increase the chances of showers and thunderstorms once again.
&&
.DISCUSSION...Water vapor imagery and 03/00Z upper-air plots show
nearly zonal flow across the Desert Southwest as Arizona lies
between high pressure over southern Chihuahua Mexico and a low
pressure system over central California. Plenty of dry mid level air
across the eastern Pacific waters and extending across northern
Baja, northwest Sonora Mexico and the southern two thirds of Arizona
and into New Mexico. The 03/00Z KTWC sounding showed significant
drying in the past 48 hours or so, with a PW of 1.2 inches compared
to 1.77 inches from Thursday afternoon. The 06Z GPS PW values from
the U of A indicate around 1.2 inches and the CIRA LPW total
indicates 1.1 inches. IR satellite imagery shows mostly clear skies
across much of Arizona at this time, with the exception being some
mid level clouds over eastern Sonora and northwest Chihuahua that
have spilled over into extreme southern Cochise county and parts
of Santa Cruz county.
As of 08Z (1 AM MST), temperatures ranged from the lower 70s to the
lower 80s which are generally around 5 to 8 degs warmer than 24
hours ago. Dewpoint temperatures range from the lower 50s to the mid
60s and these values range from 1 to 5 degs cooler/drier than 24
hours ago. As a result, relative humidity values range from 15 to 30
percent drier than this time yesterday.
Models indicate that the ridge to our south and west will build a
bit farther north and east today, becoming nearly overhead. This
will result in warmer afternoon temperatures through Tuesday as the
high remains in the same general area through that time. In
addition, expect a reduction in the threat for showers and
thunderstorms as well. Limited activity may occur today and Monday,
mostly over the White mountains and perhaps isolated activity over
southern parts of Cochise county on Tuesday. By Tuesday night into
Wednesday models indicate that return flow on the western flank of
the ridge will allow for an increase in moisture with PW`s generally
ranging from around 0.75-1.0 inches through Tuesday before climbing
back up to around 1.0-1.3 inches through early Thursday. Values will
then decrease again late in the week and into the weekend as drier
air gets ushered in from the west in response to an approaching
trough well to our northwest and north. This will once again result
in increasing daytime temperatures after a brief respite on
Wednesday and Thursday due to increasing moisture and the threat of
convection moderating temperatures a bit.
For Tucson, high temperatures will range from 2 to 4 degs below
normal today, then will hover within a degree or two either side of
normal for Monday through Friday. For next weekend, highs a few
degrees above normal. Low temperatures will range from 2 to 5 degs
above normal each morning, although the warmest mornings will occur
Wednesday and Thursday.
&&
.AVIATION...VALID THRU 04/12Z.
High pressure building in from west to east will bring more stable
conditions and mostly clear skies. Winds will generally be less than
10 kts through the period. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Drying trend is expected to start the new
week with little if any convection today through Tuesday. A brief
surge of moisture will bring some scattered showers and
thunderstorms Wednesday into Friday then we will dry out once again.
Winds will generally favor diurnal patterns, with some enhancement
in areas where afternoon northwest flow is the norm. Portions of
zone 152 could see afternoon gustiness greater than 20 mph in valley
locations Sunday through Tuesday.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
PUBLIC...Mollere
AVIATION/FIRE WEATHER...Cerniglia
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Flagstaff AZ
921 PM MST SAT JUL 2 2016
.SYNOPSIS...Sunday, drier westerly flow across Arizona will
bring drier and warmer conditions to the area heading into next
week.
&&
.DISCUSSION...The forecast was updated for the overnight time
period. The chance of precipitation was lowered to only isolated
showers and thunderstorms over southern Navajo and Apache counties
through midnight...then mainly dry after midnight.
&&
.PREV DISCUSSION /340 PM MST/...A somewhat linear convective
feature formed this afternoon along a convergence zone formed in
the wake of last nights outflow and a developing s/wv ridge to our
west. This feature is nearly aligned along the I-40 corridor,
which is problematic for travelers this afternoon.
After this evening, drier mid-level air and anticyclonic flow is
evident to our west on water vapor imagery. Additionally, warmer
temperatures aloft will develop through at least Monday with this
s/wv ridge.
At the same time, long wave troughing develops over the northwest
United States, providing a prolonged period of drier and stable
flow over the southwest. A brief intrusion of monsoon moisture may
return Wednesday or Thursday, but then right back to dry
westerlies heading into next weekend.
The net result is a period of mainly dry and warmer conditions
after today.
&&
.AVIATION...For the 06Z Package...Expect VFR conditions with a few
showers and thunderstorms on Sunday after 18Z mainly over the
mountain areas of the Mogollon Rim and Chuska Mountains. Shower
activity will diminish around 02Z. Aviation discussion not updated
for TAF amendments.
&&
.FIRE WEATHER...A drier and more stable westerly flow will bring
decreasing shower and thunderstorm coverage to northern Arizona.
Storm motion on Sunday will be from the west to the east.
Tuesday through thursday...Only daytime and isolated storms are
expected across ponderosa forests through the period as dry westerly
flow increases across the area. Elsewhere very dry with afternoon
minimum humidities belwo 15 percent.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...TC/Peterson
AVIATION...Bohlin
FIRE WEATHER...DL
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Phoenix AZ
830 PM MST SAT JUL 2 2016
.SYNOPSIS...
Subtle drying, transitioning in from the west will relegate the best
chances for afternoon and evening storms Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes
drier. Dry and warm conditions will last through much of next week,
save for a period in the mid-week where a slight increase in
humidities return.
&&
.DISCUSSION...
Anti-cyclonic mid/upper level flow, following the passing trof
yesterday/overnight stabilized the airmass in our forecast area
today. There were no aftn tstms, only stable cumulus clouds.
Additionally, upper air data showed the airmass had dried noticeably
from the west today, with the monsoon moisture boundary now
pushed into southeast AZ.
Anti-cyclonic winds aloft tomorrow and Monday, with unseasonably
warm mid level temperatures and additional moisture loss, should
provide dry and warmer weather over most of the forecast area.
Current dry and warmer forecasts look good. no updates planned.
.PREVIOUS DISCUSSION...135 PM MST...
Slightly drier and more anticyclonic flow aloft continued to spread
into central Arizona from the west early this afternoon in the wake
of a departing upper trof pushing east and into western New Mexico.
Surface dewpoints at 1 PM were still elevated and mostly ranged from
the mid 50s to low 60s, although they were trending downward and
were running 2 to 9 degrees lower than 24 hours ago. Despite
elevated moisture, the threat for thunderstorms this afternoon will
pretty much be confined to higher terrain areas east of Phoenix;
upper streamlines this afternoon will be slightly anticyclonic and
laminar with no significant deformation/difluence. With minimal upper
support we can expect some cumulus over the deserts - and we can see
that developing already on visible imagery - but that will be about
it convectively speaking. Early afternoon SPC mesoanalysis graphics
depicted CAPE over 1000 j/kg over the central deserts, but there was
a marked drying trend forecast with CAPE dropping noticeably from the
west as the afternoon progresses.
More prominent westerly flow aloft will develop as the ML/UL high
centers remain to our southeast over Mexico on Sunday through early
next week. Temperatures will gradually warm and return to normal
through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and
a return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
A drier and more stable atmosphere is forecast to move into the
greater Phoenix area through Sunday evening. Therefore mostly clear
skies are forecast. Surface winds will be light easterly, becoming
west during the afternoons and evening generally under 10 knots.
Southeast California/Southwest Arizona including KIPL and KBLH:
A drier and more stable atmosphere is forecast to move into
the greater Phoenix area through Sunday evening. Mostly clear skies
are forecast, with steady south winds 8 to 15 knots.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Southwesterly flow between the monsoon high across northern Mexico
and low pressure across the Pacific Northwest will result in above
normal temperatures and generally dry conditions. An increase in
moisture is expected Wednesday as the high shifts eastward. Drier
westerly flow across southeastern California will then battle deeper
moisture across southeastern Arizona through the remainder of the
week, with showers and thunderstorms mainly relegated to southern and
eastern Arizona. Near normal temperatures are expected mid to late
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/CB/Nolte
AVIATION...Vasquez
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Tucson AZ
821 PM MST SAT JUL 2 2016
.SYNOPSIS...Drier air moving into the region will significantly
reduce the amount of convection through Monday. The lack of showers
and cloud cover will allow for higher afternoon temperatures as
well. An increase in moisture the middle of next week will increase
the chances of showers and thunderstorms once again.
&&
.DISCUSSION...We have dried quite a bit in the past 36 hours,
with precipitable water values down to around 1 to 1.2 inches
across the area, and surface dew points generally in the 50s
(down 6 to 12 degrees over the past 24 hours). Even with the
drying trend, good instability allowed for several strong
thunderstorms southwest through southeast of Tucson over the past
few hours. With sunset things are quieting down.
The current forecast looks good with the downward trend in storms
to start the week. As this happens, we will heat back up to near
or above typical early July averages. Please see the previous
discussion below for additional details.
&&
.AVIATION...VALID THRU 04/06Z.
High pressure building in from west to east on the back side of a
mid-level trough will bring more stable conditions to start the
new week. Winds will generally be less than 10 kts with VFR
conditions throughout. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Drying trend is expected to start the new
week. Winds will generally favor diurnal patterns, with some
enhancement in areas where afternoon northwest flow is the norm.
Portions of zone 152 could see afternoon gustiness greater than 20
mph in valley locations Sunday through Tuesday.
&&
.PREV DISCUSSION...The drying trend will continue Sunday and
Monday as the ridge of high pressure aloft over Sonora and
Chihuahua shunts the deep moisture to our south and east with most
areas remaining dry. About the best we can hope for is a slight
chance of showers and thunderstorms mainly across the White
Mountains both days with the rest of the forecast area remaining
dry. Given the drier atmosphere, temperatures will will warm back
up to normal values by Monday and Tuesday. The ridge axis will be
far enough east on Tuesday to start a southerly flow of moisture
into far southeast Arizona. Thus, slight chances for showers and
thunderstorms are possible for the higher terrain and
international border area across Cochise County. The northward
push of moisture over the rest of the region is expected Wednesday
and Thursday with a more typical early July monsoon pattern then
before drier westerly flow returns for the end of the work week
and into next weekend as the mid/upper high pushes south of the
area again.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Meyer/Lader/Cantin
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Flagstaff AZ
340 PM MST SAT JUL 02 2016
.SYNOPSIS...Expect active monsoon weather into this evening. By
Sunday, drier westerly flow across Arizona will bring drier and
warmer conditions to the area heading into next week.
&&
.DISCUSSION...A somewhat linear convective feature formed this
afternoon along a convergence zone formed in the wake of last nights
outflow and a developing s/wv ridge to our west. This feature is
nearly aligned along the I-40 corridor, which is problematic for
travelers this afternoon.
After this evening, drier mid-level air and anticyclonic flow is
evident to our west on water vapor imagery. Additionally, warmer
temperatures aloft will develop through at least Monday with this
s/wv ridge.
At the same time, long wave troughing develops over the northwest
United States, providing a prolonged period of drier and stable flow
over the southwest. A brief intrusion of monsoon moisture may return
Wednesday or Thursday, but then right back to dry westerlies
heading into next weekend.
The net result is a period of mainly dry and warmer conditions after
today.
&&
.AVIATION...For the 00Z Package...until 03z Sun expect scattered
shra/tsra and isold +tsra along and north of the Mogollon Rim and
isolated coverage elsewhere. Strongest storms will contain mvfr/ifr
conditions and gusty winds. Showers and thunderstorms ending aft 03z
Sun. Aft 18z Sun isolated thunderstorm coverage for areas above 6500
feet with fair wx elsewhere. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...For Sunday and Monday, a drier and more stable
westerly flow will bring decreasing shower and thunderstorm coverage
to northern Arizona. Storm motion on Sunday will be from the west to
the east.
Tuesday through thursday...Only daytime and isolated storms are
expected across ponderosa forests through the period as dry westerly
flow increases across the area. Elsewhere very dry with afternoon
minimum humidities below 15 percent.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...Peterson
AVIATION...DL
FIRE WEATHER...DL
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Tucson AZ
200 PM MST SAT JUL 2 2016
.SYNOPSIS...Drier air moving into the region will significantly
reduce the amount of convection through Monday. The lack of showers
and cloud cover will allow for higher afternoon temperatures as
well. An increase in moisture the middle of next week will increase
the chances of showers and thunderstorms once again.
&&
.DISCUSSION...The atmosphere is starting to dry out with GPS pwat
values down to 1 inch to 1.25 inches across southeast Arizona as
ridging builds in and drier air aloft is mixing down. There were a
few showers and thunderstorms briefly this morning that formed along
the higher terrain southeast of Tucson but those quickly faded away
as they moved off the mountains with just a few light showers
redeveloping in the last half hour. One shower did pass over Sierra
Vista with one gauge recorded a half inch this morning. Have trended
pops downward this afternoon but will still depict a slight chance
of a shower or thunderstorm south and east of Tucson into early this
evening.
The drying trend will continue Sunday and Monday as the ridge of
high pressure aloft over Sonora and Chihuahua shunts the deep
moisture to our south and east with most areas remaining dry. About
the best we can hope for is a slight chance of showers and
thunderstorms mainly across the White Mountains both days with the
rest of the forecast area remaining dry. Given the drier atmosphere,
temperatures will will warm back up to normal values by Monday and
Tuesday. The ridge axis will be far enough east on Tuesday to start
a southerly flow of moisture into far southeast Arizona. Thus,
slight chances for showers and thunderstorms are possible for the
higher terrain and international border area across Cochise County.
The northward push of moisture over the rest of the region is
expected Wednesday and Thursday with a more typical early July
monsoon pattern then before drier westerly flow returns for the end
of the work week and into next weekend as the mid/upper high pushes
south of the area again.
&&
.AVIATION...VALID THRU 04/00Z.
High pressure building in from west to east on the back side of a
mid-level trough will bring stable conditions this afternoon into
early next week. Winds will generally be less than 10 kts with VFR
conditions throughout. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Drying trend is expected through early next week.
Winds will generally favor diurnal patterns, with some enhancement
in areas where afternoon northwest flow is the norm. Portions of
zone 152 could see afternoon gustiness greater than 20 mph in valley
locations Sunday through Tuesday.
&&
.TWC Watches/Warnings/Advisories...None.
&&
$$
Public...GL
Aviation/Fire Weather...Cantin
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Phoenix AZ
135 PM MST SAT JUL 2 2016
.SYNOPSIS...
A combination of lingering monsoon moisture and weather disturbances
moving eastward across the Desert Southwest will bring chances for
showers and thunderstorms through this evening over higher terrain
areas east of Phoenix. Subtle drying transitioning in from the west
will relegate the best chances for afternoon and evening storms
Sunday over the higher terrain of eastern Arizona, mainly east of
Globe. High temperatures will steadily climb into the weekend and
early next week as the atmosphere becomes drier. Dry and warm
conditions will last through much of next week, save for a period in
the mid-week where a slight increase in humidities return.
&&
.DISCUSSION...
Slightly drier and more anticyclonic flow aloft continued to spread
into central Arizona from the west early this afternoon in the wake
of a departing upper trof pushing east and into western New Mexico.
Surface dewpoints at 1 PM were still elevated and mostly ranged from
the mid 50s to low 60s, although they were trending downward and
were running 2 to 9 degrees lower than 24 hours ago. Despite
elevated moisture, the threat for thunderstorms this afternoon will
pretty much be confined to higher terrain areas east of Phoenix;
upper streamlines this afternoon will be slightly anticyclonic and
laminar with no significant deformation/difluence. With minimal upper
support we can expect some cumulus over the deserts - and we can see
that developing already on visible imagery - but that will be about
it convectively speaking. Early afternoon SPC mesoanalysis graphics
depicted CAPE over 1000 j/kg over the central deserts, but there was
a marked drying trend forecast with CAPE dropping noticeably from the
west as the afternoon progresses.
More prominent westerly flow aloft will develop as the ML/UL high
centers remain to our southeast over Mexico on Sunday through early
next week. Temperatures will gradually warm and return to normal
through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and
a return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No thunderstorms are forecast for the greater Phoenix area today,
but mountain thunderstorms to the east are still expected, especially
this afternoon. Wind speeds of 12 kts or less and fairly typical diurnal
switches are likely. Very slim chance of any outflows from mountain
storms to affect area terminals.
Southeast California/Southwest Arizona including KIPL and KBLH:
Generally clear skies through Sunday. Winds will be breezy during the
afternoon at KBLH following consistent southerly directions. Wind
speeds at KIPL will mostly fall between 8-12 kts with southeasterly
directions until early this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Southwesterly flow between the monsoon high across northern Mexico
and low pressure across the Pacific Northwest will result in above
normal temperatures and generally dry conditions. An increase in
moisture is expected Wednesday as the high shifts eastward. Drier
westerly flow across southeastern California will then battle deeper
moisture across southeastern Arizona through the remainder of the
week, with showers and thunderstorms mainly relegated to southern and
eastern Arizona. Near normal temperatures are expected mid to late
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...CB/Nolte
AVIATION...Kuhlman
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Phoenix AZ
135 PM MST SAT JUL 2 2016
.SYNOPSIS...
A combination of lingering monsoon moisture and weather disturbances
moving eastward across the Desert Southwest will bring chances for
showers and thunderstorms through this evening over higher terrain
areas east of Phoenix. Subtle drying transitioning in from the west
will relegate the best chances for afternoon and evening storms
Sunday over the higher terrain of eastern Arizona, mainly east of
Globe. High temperatures will steadily climb into the weekend and
early next week as the atmosphere becomes drier. Dry and warm
conditions will last through much of next week, save for a period in
the mid-week where a slight increase in humidities return.
&&
.DISCUSSION...
Slightly drier and more anticyclonic flow aloft continued to spread
into central Arizona from the west early this afternoon in the wake
of a departing upper trof pushing east and into western New Mexico.
Surface dewpoints at 1 PM were still elevated and mostly ranged from
the mid 50s to low 60s, although they were trending downward and
were running 2 to 9 degrees lower than 24 hours ago. Despite
elevated moisture, the threat for thunderstorms this afternoon will
pretty much be confined to higher terrain areas east of Phoenix;
upper streamlines this afternoon will be slightly anticyclonic and
laminar with no significant deformation/difluence. With minimal upper
support we can expect some cumulus over the deserts - and we can see
that developing already on visible imagery - but that will be about
it convectively speaking. Early afternoon SPC mesoanalysis graphics
depicted CAPE over 1000 j/kg over the central deserts, but there was
a marked drying trend forecast with CAPE dropping noticeably from the
west as the afternoon progresses.
More prominent westerly flow aloft will develop as the ML/UL high
centers remain to our southeast over Mexico on Sunday through early
next week. Temperatures will gradually warm and return to normal
through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and
a return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No thunderstorms are forecast for the greater Phoenix area today,
but mountain thunderstorms to the east are still expected, especially
this afternoon. Wind speeds of 12 kts or less and fairly typical diurnal
switches are likely. Very slim chance of any outflows from mountain
storms to affect area terminals.
Southeast California/Southwest Arizona including KIPL and KBLH:
Generally clear skies through Sunday. Winds will be breezy during the
afternoon at KBLH following consistent southerly directions. Wind
speeds at KIPL will mostly fall between 8-12 kts with southeasterly
directions until early this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Southwesterly flow between the monsoon high across northern Mexico
and low pressure across the Pacific Northwest will result in above
normal temperatures and generally dry conditions. An increase in
moisture is expected Wednesday as the high shifts eastward. Drier
westerly flow across southeastern California will then battle deeper
moisture across southeastern Arizona through the remainder of the
week, with showers and thunderstorms mainly relegated to southern and
eastern Arizona. Near normal temperatures are expected mid to late
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...CB/Nolte
AVIATION...Kuhlman
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Phoenix AZ
1249 PM MST SAT JUL 2 2016
.UPDATE...Updated Fire Weather Discussion.
&&
.SYNOPSIS...
A combination of lingering monsoon moisture and weather disturbances
moving eastward across the Desert Southwest will bring chances for
showers and thunderstorms early today from Phoenix eastward. Subtle
drying transitioning in from the west will relegate the best chances
for afternoon and evening storms today and Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes drier.
Dry and warm conditions will last through much of next week, save for
a period in the mid-week where a slight increase in humidities return.
&&
.DISCUSSION...
At 9 am this morning, MCS associated with a passing short wave
continued to dissipate as it passed by to the northeast of Phoenix,
mostly grazing the border of our far eastern CWA as a few
showers/storms moved past Roosevelt and to the north of Globe. IR
imagery showed sunny skies from Phoenix west, and the 12z 500mb plot
indicated pronounced anticyclonic curvature over western AZ/SERN CA
behind the exiting trof. Of course, low level moisture over south
central AZ remains elevated this morning, with 1.57 inches of PWAT
at Phoenix and central desert dewpoints in the upper 50s to mid 60s.
However, we look to be moving into a drying phase of the monsoon
starting today and heading into the first part of next week as
westerly flow aloft and deeper westerly steering flow looks to
dominate the weather pattern for Arizona. For the rest of today we
should see mostly sunny skies west of Phoenix with some afternoon
cumulus in the area, and we will see a continued chance of afternoon
storms over the higher terrain northeast of Phoenix, although any
storm that forms will head off quickly towards the east/northeast.
Rain chances in the Phoenix area will be slim this afternoon, around
10 percent at best and most areas mostly likely will not see any
convection. West/southwest steering flow is always very detrimental
to storm chances in the greater Phoenix area and with ridging moving
in from the west, chances are even slimmer than normal. Current
forecasts look to be in good shape.
.PREVIOUS DISCUSSION...
Monsoon 2016 is off to an interesting start. Outside of our
exceptional heat events typical of this time of year (which
themselves produced rare upper teen to 120F values at some locales),
an earlier-than-climatologically-usual onset of the MMB intrusion,
record-breaking late June PWAT values, dewpoints and cloudiness more
typical of August and an upper trough and shear profile usually seen
as a season-ending event have made for an busy season kick-off!
Cyclonic trough flow across northern and south-central AZ still
noted on model forecasts, RAOBs from earlier in the evening and a few
ACARS soundings. Satellite derived winds and ACARS soundings indicate
anticyclonic flow is beginning to transition further up through the
atmo profile over portions of the southern CO River Valley. UL
divergence and still rich Monsoonal moisture surface (PWAT axis of
values 1.5 inches or greater extends from Vegas southeastward through
portions of Maricopa County) remains, where thunderstorm activity
continues overnight and is lighting up area radar scopes. Until the
weak troughing and PVU fully exit the CWA later today, enough CAPE
lingers within the turbulent mean flow to support isolated shower and
thunderstorm activity through the early afternoon from Phoenix
eastward (also in locations that mainly missed out on Friday
afternoon`s excitement and atmo turning over). Southeast CA
observation sites have observed a steady decrease in moisture values
beginning Friday afternoon, with dewpoints running 3 to 5 degrees
drier over the last few hours compared to this time early Friday.
Upper troughing along with the cooler 500mb temperatures and storm-
supportive ML lapse rates will exit to our northeast as a more stable
upper air pattern builds in from west-southwest by this evening. LL
mixing ratios do not complete dry out and remain deep enough to
support evening precip activity over the eastern AZ mountains
Saturday and Sunday. More prominent westerly flow aloft will develop
as the ML/UL high centers remain to our southeast over Mexico through
early next week. Temperatures will gradually warm and return to
normal through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and a
return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No thunderstorms are forecast for the greater Phoenix area today,
but mountain thunderstorms to the east are still expected, especially
this afternoon. Wind speeds of 12 kts or less and fairly typical diurnal
switches are likely. Very slim chance of any outflows from mountain
storms to affect area terminals.
Southeast California/Southwest Arizona including KIPL and KBLH:
Generally clear skies through Sunday. Winds will be breezy during the
afternoon at KBLH following consistent southerly directions. Wind
speeds at KIPL will mostly fall between 8-12 kts with southeasterly
directions until early this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Southwesterly flow between the monsoon high across northern Mexico
and low pressure across the Pacific Northwest will result in above
normal temperatures and generally dry conditions. An increase in
moisture is expected Wednesday as the high shifts eastward. Drier
westerly flow across southeastern California will then battle deeper
moisture across southeastern Arizona through the remainder of the
week, with showers and thunderstorms mainly relegated to southern and
eastern Arizona. Near normal temperatures are expected mid to late
week.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...CB
PREVIOUS DISCUSSION...Nolte
AVIATION...Kuhlman
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Flagstaff AZ
955 AM MST SAT JUL 02 2016
.SYNOPSIS...Expect active monsoon weather again today. Starting
Sunday, drier westerly flow across Arizona will bring a downturn
in activity heading into next week.
&&
.DISCUSSION...Long lived gravity wave/outflow/decaying MCS from
Nevada last night has finally exited our eastern border. Behind
this wave, subsidence and building hghts will limit convective
development today, despite decent moisture profiles. Our current
POPs may be a little high, but they are in the ballpark.
After today, drier and stable westerly flow will take over for the
remainder of the holiday weekend and into next week. Expect fair and
seasonably warm conditions as a result.
Zones/grids look good, no updates needed.
&&
.AVIATION...For the 18Z Package...until 03z Sun expect scattered
shra/tsra and isold +tsra across northern Arizona, then decreasing
coverage. Strongest storms will contain mvfr/ifr conditions and
gusty winds. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Scattered showers and thunderstorms are expected to
persist again today, with only a few isolated storms on Sunday as
drier air filters into the area. Storm motion will be from the west
to the east.
Monday through Wednesday...Only a few isolated storms are expected
through the period over the higher terrain as dry westerly flow
develops across the area.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...Peterson
AVIATION...DL
FIRE WEATHER...JJ
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Phoenix AZ
925 AM MST SAT JUL 2 2016
.SYNOPSIS...
A combination of lingering monsoon moisture and weather disturbances
moving eastward across the Desert Southwest will bring chances for
showers and thunderstorms early today from Phoenix eastward. Subtle
drying transitioning in from the west will relegate the best chances
for afternoon and evening storms today and Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes drier.
Dry and warm conditions will last through much of next week, save for
a period in the mid-week where a slight increase in humidities return.
&&
.DISCUSSION...
At 9 am this morning, MCS associated with a passing short wave
continued to dissipate as it passed by to the northeast of Phoenix,
mostly grazing the border of our far eastern CWA as a few
showers/storms moved past Roosevelt and to the north of Globe. IR
imagery showed sunny skies from Phoenix west, and the 12z 500mb plot
indicated pronounced anticyclonic curvature over western AZ/SERN CA
behind the exiting trof. Of course, low level moisture over south
central AZ remains elevated this morning, with 1.57 inches of PWAT
at Phoenix and central desert dewpoints in the upper 50s to mid 60s.
However, we look to be moving into a drying phase of the monsoon
starting today and heading into the first part of next week as
westerly flow aloft and deeper westerly steering flow looks to
dominate the weather pattern for Arizona. For the rest of today we
should see mostly sunny skies west of Phoenix with some afternoon
cumulus in the area, and we will see a continued chance of afternoon
storms over the higher terrain northeast of Phoenix, although any
storm that forms will head off quickly towards the east/northeast.
Rain chances in the Phoenix area will be slim this afternoon, around
10 percent at best and most areas mostly likely will not see any
convection. West/southwest steering flow is always very detrimental
to storm chances in the greater Phoenix area and with ridging moving
in from the west, chances are even slimmer than normal. Current
forecasts look to be in good shape.
.PREVIOUS DISCUSSION...
Monsoon 2016 is off to an interesting start. Outside of our
exceptional heat events typical of this time of year (which
themselves produced rare upper teen to 120F values at some locales),
an earlier-than-climatologically-usual onset of the MMB intrusion,
record-breaking late June PWAT values, dewpoints and cloudiness more
typical of August and an upper trough and shear profile usually seen
as a season-ending event have made for an busy season kick-off!
Cyclonic trough flow across northern and south-central AZ still
noted on model forecasts, RAOBs from earlier in the evening and a few
ACARS soundings. Satellite derived winds and ACARS soundings indicate
anticyclonic flow is beginning to transition further up through the
atmo profile over portions of the southern CO River Valley. UL
divergence and still rich Monsoonal moisture surface (PWAT axis of
values 1.5 inches or greater extends from Vegas southeastward through
portions of Maricopa County) remains, where thunderstorm activity
continues overnight and is lighting up area radar scopes. Until the
weak troughing and PVU fully exit the CWA later today, enough CAPE
lingers within the turbulent mean flow to support isolated shower and
thunderstorm activity through the early afternoon from Phoenix
eastward (also in locations that mainly missed out on Friday
afternoon`s excitement and atmo turning over). Southeast CA
observation sites have observed a steady decrease in moisture values
beginning Friday afternoon, with dewpoints running 3 to 5 degrees
drier over the last few hours compared to this time early Friday.
Upper troughing along with the cooler 500mb temperatures and storm-
supportive ML lapse rates will exit to our northeast as a more stable
upper air pattern builds in from west-southwest by this evening. LL
mixing ratios do not complete dry out and remain deep enough to
support evening precip activity over the eastern AZ mountains
Saturday and Sunday. More prominent westerly flow aloft will develop
as the ML/UL high centers remain to our southeast over Mexico through
early next week. Temperatures will gradually warm and return to
normal through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and a
return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No thunderstorms are forecast for the greater Phoenix area today,
but mountain thunderstorms to the east are still expected, especially
this afternoon. Wind speeds of 12 kts or less and fairly typical diurnal
switches are likely. Very slim chance of any outflows from mountain
storms to affect area terminals.
Southeast California/Southwest Arizona including KIPL and KBLH:
Generally clear skies through Sunday. Winds will be breezy during the
afternoon at KBLH following consistent southerly directions. Wind
speeds at KIPL will mostly fall between 8-12 kts with southeasterly
directions until early this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Monday through Friday: The monsoon high will rebuild across
southeastern Arizona Monday, resulting in above normal temperatures
and generally dry conditions. An increase in moisture is expected
Wednesday as the high shifts eastward. Drier westerly flow across
southeastern California will battle deeper moisture across
southeastern Arizona through the remainder of the week, with showers
and thunderstorms mainly relegated to southern and eastern Arizona.
Near normal temperatures are expected mid to late 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...CB
PREVIOUS DISCUSSION...Nolte
AVIATION...Kuhlman
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Phoenix AZ
925 AM MST SAT JUL 2 2016
.SYNOPSIS...
A combination of lingering monsoon moisture and weather disturbances
moving eastward across the Desert Southwest will bring chances for
showers and thunderstorms early today from Phoenix eastward. Subtle
drying transitioning in from the west will relegate the best chances
for afternoon and evening storms today and Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes drier.
Dry and warm conditions will last through much of next week, save for
a period in the mid-week where a slight increase in humidities return.
&&
.DISCUSSION...
At 9 am this morning, MCS associated with a passing short wave
continued to dissipate as it passed by to the northeast of Phoenix,
mostly grazing the border of our far eastern CWA as a few
showers/storms moved past Roosevelt and to the north of Globe. IR
imagery showed sunny skies from Phoenix west, and the 12z 500mb plot
indicated pronounced anticyclonic curvature over western AZ/SERN CA
behind the exiting trof. Of course, low level moisture over south
central AZ remains elevated this morning, with 1.57 inches of PWAT
at Phoenix and central desert dewpoints in the upper 50s to mid 60s.
However, we look to be moving into a drying phase of the monsoon
starting today and heading into the first part of next week as
westerly flow aloft and deeper westerly steering flow looks to
dominate the weather pattern for Arizona. For the rest of today we
should see mostly sunny skies west of Phoenix with some afternoon
cumulus in the area, and we will see a continued chance of afternoon
storms over the higher terrain northeast of Phoenix, although any
storm that forms will head off quickly towards the east/northeast.
Rain chances in the Phoenix area will be slim this afternoon, around
10 percent at best and most areas mostly likely will not see any
convection. West/southwest steering flow is always very detrimental
to storm chances in the greater Phoenix area and with ridging moving
in from the west, chances are even slimmer than normal. Current
forecasts look to be in good shape.
.PREVIOUS DISCUSSION...
Monsoon 2016 is off to an interesting start. Outside of our
exceptional heat events typical of this time of year (which
themselves produced rare upper teen to 120F values at some locales),
an earlier-than-climatologically-usual onset of the MMB intrusion,
record-breaking late June PWAT values, dewpoints and cloudiness more
typical of August and an upper trough and shear profile usually seen
as a season-ending event have made for an busy season kick-off!
Cyclonic trough flow across northern and south-central AZ still
noted on model forecasts, RAOBs from earlier in the evening and a few
ACARS soundings. Satellite derived winds and ACARS soundings indicate
anticyclonic flow is beginning to transition further up through the
atmo profile over portions of the southern CO River Valley. UL
divergence and still rich Monsoonal moisture surface (PWAT axis of
values 1.5 inches or greater extends from Vegas southeastward through
portions of Maricopa County) remains, where thunderstorm activity
continues overnight and is lighting up area radar scopes. Until the
weak troughing and PVU fully exit the CWA later today, enough CAPE
lingers within the turbulent mean flow to support isolated shower and
thunderstorm activity through the early afternoon from Phoenix
eastward (also in locations that mainly missed out on Friday
afternoon`s excitement and atmo turning over). Southeast CA
observation sites have observed a steady decrease in moisture values
beginning Friday afternoon, with dewpoints running 3 to 5 degrees
drier over the last few hours compared to this time early Friday.
Upper troughing along with the cooler 500mb temperatures and storm-
supportive ML lapse rates will exit to our northeast as a more stable
upper air pattern builds in from west-southwest by this evening. LL
mixing ratios do not complete dry out and remain deep enough to
support evening precip activity over the eastern AZ mountains
Saturday and Sunday. More prominent westerly flow aloft will develop
as the ML/UL high centers remain to our southeast over Mexico through
early next week. Temperatures will gradually warm and return to
normal through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and a
return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No thunderstorms are forecast for the greater Phoenix area today,
but mountain thunderstorms to the east are still expected, especially
this afternoon. Wind speeds of 12 kts or less and fairly typical diurnal
switches are likely. Very slim chance of any outflows from mountain
storms to affect area terminals.
Southeast California/Southwest Arizona including KIPL and KBLH:
Generally clear skies through Sunday. Winds will be breezy during the
afternoon at KBLH following consistent southerly directions. Wind
speeds at KIPL will mostly fall between 8-12 kts with southeasterly
directions until early this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Monday through Friday: The monsoon high will rebuild across
southeastern Arizona Monday, resulting in above normal temperatures
and generally dry conditions. An increase in moisture is expected
Wednesday as the high shifts eastward. Drier westerly flow across
southeastern California will battle deeper moisture across
southeastern Arizona through the remainder of the week, with showers
and thunderstorms mainly relegated to southern and eastern Arizona.
Near normal temperatures are expected mid to late 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...CB
PREVIOUS DISCUSSION...Nolte
AVIATION...Kuhlman
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Tucson AZ
817 AM MST SAT JUL 2 2016
.SYNOPSIS...Drier air moving into the region will significantly
reduce the amount of convection expected today with little if any
expected Sunday and Monday. The lack of showers and cloud cover will
allow for higher afternoon temperatures as well. An increase in
moisture the middle of next week will increase the chances of showers
and thunderstorms once again.
&&
.DISCUSSION...Latest IR/WV imagery shows mostly clear skies from
Tucson south and westward with partly to mostly cloudy skies north
and east of Tucson. A few showers and thunderstorms are now
occurring over the Upper Gila River Valley near Safford but these
are gradually weakening. Meanwhile, a weakening forward propagating
MCS over north/central Arizona continues to move towards the White
Mountains this morning which may result in a few thunderstorms
across northern Graham and Greenlee counties later this morning. For
the rest of the area, the mid and upper levels have dried out
considerably but boundary layer moisture remains adequate with PWAT
values of 1.25 to 1.5 inches. Latest HRRR runs and UofA WRF NAM/GFS
show just enough boundary layer moisture for isolated to scattered
thunderstorms from the Tucson area south and eastward today. With
ridging building in, the storms should generally struggle so we
aren`t expecting significant impacts, but brief heavy rain is
possible.
The drying trend will continue Sunday and Monday as the ridge of
high pressure aloft over Sonora shunts the deep moisture to our
south and east with most areas remaining dry and otherwise just a
slight chance of showers and thunderstorms mainly across the White
Mountains. With ridging building in, temperatures will warm back up
to near normal values by Monday and Tuesday. The ridge axis will be
far enough east on Tuesday to start a southerly flow of moisture
into southeast Arizona. Thus, slight chances for showers and
thunderstorms are possible for the higher terrain and international
border then. The northward push of moisture over the rest of the
region is expected Wednesday and Thursday with a more typical early
July monsoon pattern then before drier westerly flow returns for the
end of the work week and into next weekend.
&&
.AVIATION...VALID THRU 03/18Z.
Considerably fewer showers and thunderstorms today, mainly for areas
south and east of Tucson. Mostly clear skies this morning for the
terminals, but during the afternoon hours, ceilings generally 10-15K
ft. Gusty winds and brief MVFR conditions in heavy rainfall are
likely near storms where wind gusts could exceed 30 kts. Otherwise
surface winds generally 10 kts or less. Aviation discussion not
updated for TAF amendments.
&&
.FIRE WEATHER...Moisture will begin to diminish across the region
beginning today and continuing through Tuesday, resulting in a
decrease in the coverage of showers and thunderstorms and a slight
bump up in afternoon temperatures. Some moisture will begin to
return to the area Wednesday for a general increase in showers and
thunderstorms once again.
&&
.TWC Watches/Warnings/Advisories...None.
&&
$$
GL
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Flagstaff AZ
350 PM MST SUN JUL 03 2016
.SYNOPSIS...Westerly flow across the southwest will bring
drier and warmer conditions to the area heading into next week.
&&
.DISCUSSION...A few storms formed today near the Utah border
where moisture and instability profiles are a bit more favorable.
This will be short-lived as drier and more stable air continues to
move into the Southwest. After today, a regime of dry westerly flow
will develop over the region. Chances for showers will be near zero
through at least the next seven days, after today.
&&
.AVIATION...For the 00Z Package...Expect VFR conditions to prevail
over the next 24 hours. Isolated SHRA/TSRA possible Monday from 18Z-
02Z over the White Mountains. Aviation discussion not updated for
TAF amendments.
&&
.FIRE WEATHER...Dry weather is expected Monday and Tuesday as dry
westerly flow takes over across the area. Only a slight chance of
afternoon thunderstorms exists across the White Mountains Monday.
Wednesday through Friday...A chance for afternoon thunderstorms
exists each day across the White Mountains. Elsewhere...Dry weather
can be expected with afternoon relative humidity values generally
around 15 percent.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...Peterson
AVIATION...Mottice
FIRE WEATHER...Mottice
For Northern Arizona weather information visit
weather.gov/flagstaff
[top]
Area Forecast Discussion
National Weather Service Phoenix AZ
236 PM MST SUN JUL 3 2016
.UPDATE...
Updated Aviation and Fire Weather sections.
&&
.SYNOPSIS...
Subtle drying transitioning in from the west will relegate the best
chances for afternoon and evening storms Sunday to the higher
terrain of eastern Arizona. High temperatures will steadily climb
and this next week as the atmosphere becomes drier. Dry and warm
conditions will last through much of the week, save for a period in
the mid-week where a slight increase in humidities return. Further
drying from the west is possible into the weekend with near average
temperatures and mostly clear skies.
&&
.DISCUSSION...
Although the atmosphere over southern Arizona and far southeast
California is far from bone dry, the large-scale weather pattern
over the western states has shifted and we are now looking at a
respite from our typical daily monsoon thunderstorm activity.
Stronger westerly flow aloft has been setting up into the Pacific
northwest, shunting the upper high far to the south resulting in a
drying west to southwest flow aloft across Arizona. 12z 500mb plot
showed anticyclonic flow across the state while the area soundings
displayed deep general west flow aloft through the column. PWAT
values have fallen quite a bit with Phoenix reporting just 1.19
inches this morning. At 1 pm the surface dewpoints over the central
AZ deserts were mostly in the mid 50s but had fallen 3 to 9 degrees
over the past 24 hours. Early afternoon satellite imagery showed
some cumulus developing over south central AZ with pretty much sunny
skies west of Maricopa county, and there was little deep convection
developing over higher terrain areas over central or southeast
Arizona. Based on the morning Phoenix sounding, CAPE was minimal and
skinny and further drying in the low levels would pretty much
eliminate what CAPE was present. It is thus interesting to look at
the current SPC mesoanalysis graphic which showed 500-1000 j/kg of
MLCAPE over south-central AZ; this seems overdone and in any case
this CAPE was forecast to drop markedly as the afternoon wears on.
Based on the extremely unfavorable westerly steering flow and
anticyclonic flow aloft, there is little if any chance for desert
storms today and only a slight chance over higher terrain areas east
of Phoenix - mainly east of Globe.
During the early part of the week this pattern will continue as
troffing strengthens over the Pacific northwest and west/southwest
flow aloft over Arizona keeps thinning the moisture profile
resulting in mostly clear skies and little if any chance for storms -
even over southern Gila County. Due to the gradual drying of the air
mass and the considerable sunshine expected, high temp Monday and
Tuesday will climb slightly with hottest deserts reaching around 110
degrees both days.
More noticeable spread enters the temperature forecasts for Wednesday
and beyond, especially the morning lows, tied to the depth and
persistence of a mid-week moisture intrusion from the south. Up until
this point, the ML/UL high centers remained to our southeast over
Mexico. GFS model trends with the intrusion have been a bit drier the
last few nights, while the ECMWF remains a higher on the 850mb Td
fields for Wednesday and Thursday. Forecast streamlines through the
column struggle to take up anything with an easterly influence, with
850-700mb winds turning southerly for 24 hr window or so. While it`s
still a ways out, ample moisture over the Sierra Madre and inverted
wave movement along the Mexican Riviera and Baja Peninsula could
trigger some larger storm complexes that send outflow intrusions
northward, rather than our depending on easterly to southeasterly
advection flow. Resulting temperatures forecasts are rather steady
state and near seasonal normals, but any moisture insulation could
shave a few degrees off the limits on the diurnal range, more likely
for locations east of the CO River Valley. Slight storm chances enter
into SE AZ, the White Mtns and the Rim for Wednesday and some of the
mountainous locations of southern Gila county for Thursday afternoon.
With still modest westerly flow progged through the majority of the
column, conditions are not looking favorable for outflow intrusions
to make their way onto the desert floors at this time. Longwave
troughing remains over the West Coast for late this week and the
coming weekend with the potential for further dry advection from the
west. Zonal heights aloft over the Southwest should result in near
average temperatures, dry conditions for nearly all forecast locales
under mostly clear skies.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
Some cumulus and altocumulus can be expected the rest of the
afternoon into the evening...towering cumulus over the higher terrain
north and east of Phoenix metro. Westerly surface winds will
predominate through at least 06Z over Phoenix metro...lingering past
07Z at PHX. Expect a repeat Monday with a bit stronger speeds in the
afternoon.
Southeast California/Southwest Arizona including KIPL and KBLH:
Clear skies through Monday. Surface winds will favor southerly
directions through Monday. An exception will be downvalley winds at
night east of the Lower Colorado River Valley. This will be
especially true west of the Imperial Valley near the mountains with
local gusts in the evening of 25-30 kts.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday: Stronger than usual early July southwest
flow across the region will result in slightly above normal
temperatures and generally dry conditions. An increase in moisture
Wednesday and Thursday could lead to a few thunderstorms over higher
terrain of southern Gila and far eastern Maricopa/Pinal counties with
little to no chance of wetting rains elsewhere. Moisture declines
again Friday through Sunday with storm chances going away. With this
drier overall pattern, afternoon minimum humidity levels will fall
back into a 10 to 20 percent range...lower west of the Lower Colorado
River Valley...with fair to good overnight recovery. Afternoon wind
speeds will be somewhat stronger than typical for early July...most
noticeably on Wednesday.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...CB/Nolte
AVIATION...AJ
FIRE WEATHER...AJ/MO
Area Forecast Discussion
National Weather Service Phoenix AZ
140 PM MST SUN JUL 3 2016
.SYNOPSIS...
Subtle drying transitioning in from the west will relegate the best
chances for afternoon and evening storms Sunday to the higher
terrain of eastern Arizona. High temperatures will steadily climb
and this next week as the atmosphere becomes drier. Dry and warm
conditions will last through much of the week, save for a period in
the mid-week where a slight increase in humidities return. Further
drying from the west is possible into the weekend with near average
temperatures and mostly clear skies.
&&
.DISCUSSION...
Although the atmosphere over southern Arizona and far southeast
California is far from bone dry, the large-scale weather pattern
over the western states has shifted and we are now looking at a
respite from our typical daily monsoon thunderstorm activity.
Stronger westerly flow aloft has been setting up into the Pacific
northwest, shunting the upper high far to the south resulting in a
drying west to southwest flow aloft across Arizona. 12z 500mb plot
showed anticyclonic flow across the state while the area soundings
displayed deep general west flow aloft through the column. PWAT
values have fallen quite a bit with Phoenix reporting just 1.19
inches this morning. At 1 pm the surface dewpoints over the central
AZ deserts were mostly in the mid 50s but had fallen 3 to 9 degrees
over the past 24 hours. Early afternoon satellite imagery showed
some cumulus developing over south central AZ with pretty much sunny
skies west of Maricopa county, and there was little deep convection
developing over higher terrain areas over central or southeast
Arizona. Based on the morning Phoenix sounding, CAPE was minimal and
skinny and further drying in the low levels would pretty much
eliminate what CAPE was present. It is thus interesting to look at
the current SPC mesoanalysis graphic which showed 500-1000 j/kg of
MLCAPE over south-central AZ; this seems overdone and in any case
this CAPE was forecast to drop markedly as the afternoon wears on.
Based on the extremely unfavorable westerly steering flow and
anticyclonic flow aloft, there is little if any chance for desert
storms today and only a slight chance over higher terrain areas east
of Phoenix - mainly east of Globe.
During the early part of the week this pattern will continue as
troffing strengthens over the Pacific northwest and west/southwest
flow aloft over Arizona keeps thinning the moisture profile
resulting in mostly clear skies and little if any chance for storms -
even over southern Gila County. Due to the gradual drying of the air
mass and the considerable sunshine expected, high temp Monday and
Tuesday will climb slightly with hottest deserts reaching around 110
degrees both days.
More noticeable spread enters the temperature forecasts for Wednesday
and beyond, especially the morning lows, tied to the depth and
persistence of a mid-week moisture intrusion from the south. Up until
this point, the ML/UL high centers remained to our southeast over
Mexico. GFS model trends with the intrusion have been a bit drier the
last few nights, while the ECMWF remains a higher on the 850mb Td
fields for Wednesday and Thursday. Forecast streamlines through the
column struggle to take up anything with an easterly influence, with
850-700mb winds turning southerly for 24 hr window or so. While it`s
still a ways out, ample moisture over the Sierra Madre and inverted
wave movement along the Mexican Riviera and Baja Peninsula could
trigger some larger storm complexes that send outflow intrusions
northward, rather than our depending on easterly to southeasterly
advection flow. Resulting temperatures forecasts are rather steady
state and near seasonal normals, but any moisture insulation could
shave a few degrees off the limits on the diurnal range, more likely
for locations east of the CO River Valley. Slight storm chances enter
into SE AZ, the White Mtns and the Rim for Wednesday and some of the
mountainous locations of southern Gila county for Thursday afternoon.
With still modest westerly flow progged through the majority of the
column, conditions are not looking favorable for outflow intrusions
to make their way onto the desert floors at this time. Longwave
troughing remains over the West Coast for late this week and the
coming weekend with the potential for further dry advection from the
west. Zonal heights aloft over the Southwest should result in near
average temperatures, dry conditions for nearly all forecast locales
under mostly clear skies.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No aviation impacts through Monday morning under mostly clear skies.
Confidence is good that wind shifts/transition to an easterly
component overnight will occur later than typical, and similarly the
afternoon switch back to a westerly direction will occur earlier
than usual.
Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation impacts through Monday morning under clear skies. Sfc
winds will generally favor a south to southwest direction, though
some periods yielding a light and variable direction will be
possible towards sunrise.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Stronger than usual early July southwest flow across the region will
result in slightly above normal temperatures and generally dry
conditions. An increase in moisture Wednesday and Thursday could
lead to a few thunderstorms over higher terrain of southern Gila and
far eastern Maricopa/Pinal counties with little to no chance of
wetting rains elsewhere. With this drier pattern, afternoon minimum
humidity levels will fall back into a 10 to 20 percent range with
fair to good overnight recovery. Wind speeds will be somewhat
stronger than typical for early July with more frequent afternoon
gusts especially around higher terrain features.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...CB/Nolte
AVIATION...MO
FIRE WEATHER...MO/Hirsch
[top]
Area Forecast Discussion
National Weather Service Tucson AZ
138 PM MST SUN JUL 3 2016
.SYNOPSIS...A dry air mass with westerly flow aloft will
significantly limit the amount of thunderstorms through Tuesday.
The lack of showers and cloud cover will allow for higher afternoon
temperatures as well. A modest increase in moisture for the middle
of this week will increase shower and thunderstorm chances Wednesday
and Thursday mainly from Tucson south and eastward. Another drier
and warmer pattern moves in for next weekend.
&&
.DISCUSSION...A very quiet early July afternoon compared to what
we`ve seen over the past week or so as cumulus cloud build-ups are
generally near the higher terrain. This is due to ridging aloft just
south of the region and a drier airmass as surface dewpoints have
now dropped into the upper 40s to mid 50s. A couple of
thunderstorms have formed off the Chiricahua mountains in the past
hour or so and we`ll have a few more storms form off the mountains
of Santa Cruz and Cochise counties this afternoon then drifting
briefly into the adjacent lower elevations. Any storms should
quickly fade around sunset with skies becoming mostly clear
overnight. It will be even more of a struggle Monday and Tuesday to
get much more than some cumulus build-ups in these same higher
terrain areas as high pressure aloft remains centered just to our
south east. With the drier air, temperatures will be near seasonal
normals the next few days.
By Wednesday and Thursday a return flow of moisture around the high
pressure which will then be located near the Big Bend of Texas will
try to bring some increased moisture to the area. Latest
NAM/SREF/GEFS have backed off a bit with the moisture and thus
northward push of the moisture as the flow remains a bit more
southwesterly. The deterministic GFS is the most aggressive with the
moisture push north and west. Have made some minor tweaks to the
PoPs for Wednesday and Thursday with the best chance of storms being
south and east of Tucson. The moisture increase Wednesday and
Thursday will be short lived as westerly flow aloft returns by
Friday as any remaining chances of storms on Friday will be in the
southeast portions of the forecast area. Dry weather is expected
next weekend. Expect a few degrees of cooling Wednesday and Thursday
with temperatures starting to warm back up Friday and next weekend.
&&
.AVIATION...VALID THRU 05/00Z.
High pressure aloft will result in drier conditions with mostly
clear skies for the terminals and partly cloudy skies for the
mountains through sunset. A slight chc of SHRA/TSRA is possible
mainly for the mountains through about 04/03Z, then skies becoming
mostly clear overnight. A few mountain cloud build-ups are expected
again Monday afternoon. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Dry conditions with little convection through
Tuesday. A brief push of moisture will bring some scattered showers
and thunderstorms Wednesday into Friday then we will dry out once
again. Winds will generally favor diurnal patterns, with some
enhancement in areas where afternoon northwest flow is the norm.
Portions of zone 152 could see afternoon gustiness greater than 20
mph in valley locations through Tuesday.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
GL
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Flagstaff AZ
1010 AM MST SUN JUL 03 2016
.SYNOPSIS...Westerly flow across the southwest will bring
drier and warmer conditions to the area heading into next week.
&&
.DISCUSSION...Mostly fair weather cumulus expected today as drier
and more stable air begins to move into the southwest. Just enough
remnant moisture and instability remains today for a few showers to
develop. After today, a long loved regime of dry westerly flow will
develop over the region. Chances for showers will be near zero
through at least the next seven days, after today.
Zones/grids look good, no updates.
&&
.AVIATION...For the 18Z Package...Expect VFR conditions to prevail
over the next 24 hours. Isolated SHRA/TSRA possible 18Z-02Z mainly
over the higher terrain from Mogollon Rim and White Mtns northward.
Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...A drier and more stable westerly flow will bring
decreasing shower and thunderstorm coverage to northern Arizona
today and Monday. Any isolated storms that develop today will move
from west to east.
Tuesday through Thursday...Westerly flow brings mainly dry
conditions with breezy afternoons. Temperatures near normal.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...Peterson
AVIATION...Mottice
FIRE WEATHER...JJ
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Tucson AZ
832 AM MST SUN JUL 3 2016
.SYNOPSIS...Drier air moving into the region will significantly
reduce the amount of thunderstorms through Tuesday. The lack of
showers and cloud cover will allow for higher afternoon temperatures
as well. An increase in moisture the middle of next week will
increase the chances of showers and thunderstorms once again.
&&
.DISCUSSION...Latest wv imagery and upper air plots indicate mid and
upper level ridging just to our south with generally westerly flow
aloft. Still some decent moisture in the boundary layer below about
650 mb and very dry above. Precipitable water off the 12z KTWC
sounding came in at 1.26 inches. As boundary layer moisture
continues to decrease, moisture will be very limited to generate
showers and thunderstorms this afternoon but can`t rule out slight
chances in the higher terrain over Cochise and Santa Cruz counties
along with the White Mountains. It will be even more of a struggle
Monday and Tuesday to get much more than some cumulus build-ups in
these same higher terrain areas with high pressure aloft centered
just to our south east. With the drier air, temperatures will be
near seasonal normals the next few days.
By Wednesday and Thursday a return flow of moisture around the high
pressure which will then be located near the Big Bend of Texas will
bring chances of showers and thunderstorms back to much of Southeast
Arizona. However, this will be short lived as westerly flow aloft
returns by Friday and continues next weekend with a drier pattern
returning. Expect a few degrees of cooling Wednesday through Friday
then warming back up next weekend.
&&
.AVIATION...VALID THRU 04/18Z.
High pressure building in from west to east will bring more stable
conditions and mostly clear skies. Winds will generally be less than
10 kts through the period. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Drying trend is expected to start the new
week with little if any convection today through Tuesday. A brief
surge of moisture will bring some scattered showers and
thunderstorms Wednesday into Friday then we will dry out once again.
Winds will generally favor diurnal patterns, with some enhancement
in areas where afternoon northwest flow is the norm. Portions of
zone 152 could see afternoon gustiness greater than 20 mph in valley
locations Sunday through Tuesday.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
GL
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Phoenix AZ
815 AM MST SUN JUL 3 2016
.SYNOPSIS...
Subtle drying transitioning in from the west will relegate the best
chances for afternoon and evening storms Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes drier.
Dry and warm conditions will last through much of next week, save for
a period in the mid-week where a slight increase in humidities
return. Further drying from the west is possible into next weekend
with near average temperatures and mostly clear skies.
&&
.DISCUSSION...
Early morning plot data as well as sounding data showed upper
ridging in place across Arizona with a deep profile of westerly flow
aloft through most of the atmosphere. PWAT values at Phoenix had
dropped to 1.19 inches and there was little if any CAPE present in
the sounding; additional drying in the profile will eliminate what
skinny CAPE is currently present. Surface dewpoints over the central
deserts were down 6-12 degrees from 24 hours ago and were mostly in
the mid to upper 50s at 8 am. IR imagery this morning showed
basically clear skies area-wide with just a few patches of mid cloud
forming to the southwest of Phoenix. Current SPC mesoanalysis
graphics showed just a few hundred j/kg of MLCAPE over the central
deserts and forecast over 1000 j/kg by early afternoon which seems a
bit excessive as latest NAM run only calls for aorund 300-400 j/kg
this afternoon. Given the persistent strong westerly flow aloft that
will be present this afternoon and tendency to mix down drier air to
the surface, expect that if any storms develop they will be over the
mountains to the east of Phoenix and only some aternoon cumulus will
develop over the deserts. Current forecasts have this covered and
look to be in good shape. No updates are planned attm.
.PREVIOUS DISCUSSION...
Building anticyclonic heights noted over the region both in the
evening RAOBs as well as long-framed regional radar loops, with
returns almost oriented on a northward moving concave arc from
Barstow, CA through the AZ White Mountains. Westerly mean and UL
flow has returned, with storm tops quickly being lofted
northeastward on this evening`s stronger storms. The SE CA and AZ
Lower Deserts will be in for several quiet days as several strong
Pacific troughs transition through the West Coast and Intermountain
West. Water vapor imagery overnight depicts three such trough
circulations landfalling or moving towards the West Coast. The
southern most is significantly dry through the mid and upper levels
over the L.A. Basin. Unseasonably strong westerly flow noted 500mb
and above, with a 50-55kt 300mb jet skirting across northern AZ later
tonight and into Monday, tied to the southern most shortwave. Loss of
our moisture advecting wind profile will allow for some thinning of
PWATs and LL dewpoints with daytime mixing, drawing them out of the
MMB richness. Resulting PoP forecasts save for some lingering PoPs on
the Rim for today, are well below climo and have nil chances for the
lower deserts and non-zero but still non-weather mentionable values
for the Zone 24/Southern Gila mountains. Under clear skies and fairly
typical winds, temperatures will settle out within range of early
July normals, 107F for Phoenix and Yuma both today and Monday. Subtle
variances in 1000-500mb thicknesses and a peak of 850mb temperatures
on Tuesday could support temperatures near 110F for the warmer
deserts, likely the warmest day but staying below excessive heat
thresholds.
More noticeable spread enters the temperature forecasts for Wednesday
and beyond, especially the morning lows, tied to the depth and
persistence of a mid-week moisture intrusion from the south. Up until
this point, the ML/UL high centers remained to our southeast over
Mexico. GFS model trends with the intrusion have been a bit drier the
last few nights, while the ECMWF remains a higher on the 850mb Td
fields for Wednesday and Thursday. Forecast streamlines through the
column struggle to take up anything with an easterly influence, with
850-700mb winds turning southerly for 24 hr window or so. While it`s
still a ways out, ample moisture over the Sierra Madre and inverted
wave movement along the Mexican Riviera and Baja Peninsula could
trigger some larger storm complexes that send outflow intrusions
northward, rather than our depending on easterly to southeasterly
advection flow. Resulting temperatures forecasts are rather steady
state and near seasonal normals, but any moisture insulation could
shave a few degrees off the limits on the diurnal range, more likely
for locations east of the CO River Valley. Slight storm chances enter
into SE AZ, the White Mtns and the Rim for Wednesday and some of the
mountainous locations of southern Gila county for Thursday afternoon.
With still modest westerly flow progged through the majority of the
column, conditions are not looking favorable for outflow intrusions
to make their way onto the desert floors at this time. Longwave
troughing remains over the West Coast for late this week and the
coming weekend with the potential for further dry advection from the
west. Zonal heights aloft over the Southwest should result in near
average temperatures, dry conditions for nearly all forecast locales
under mostly clear skies.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No aviation impacts through Monday morning under mostly clear skies.
Confidence is good that wind shifts/transition to an easterly
component overnight will occur later than typical, and similarly the
afternoon switch back to a westerly direction will occur earlier
than usual.
Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation impacts through Monday morning under clear skies. Sfc
winds will generally favor a south to southwest direction, though
some periods yielding a light and variable direction will be
possible towards sunrise.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Stronger than usual early July southwest flow across the region will
result in slightly above normal temperatures and generally dry
conditions. An increase in moisture Wednesday and Thursday could
lead to a few thunderstorms over higher terrain of southern Gila and
far eastern Maricopa/Pinal counties with little to no chance of
wetting rains elsewhere. With this drier pattern, afternoon minimum
humidity levels will fall back into a 10 to 20 percent range with
fair to good overnight recovery. Wind speeds will be somewhat
stronger than typical for early July with more frequent afternoon
gusts especially around higher terrain features.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...CB
PREVIOUS DISCUSSION...Nolte
AVIATION...MO
FIRE WEATHER...MO/Hirsch
Area Forecast Discussion
National Weather Service Phoenix AZ
440 AM MST SUN JUL 3 2016
...Updated Aviation and Fire Weather...
.SYNOPSIS...
Subtle drying transitioning in from the west will relegate the best
chances for afternoon and evening storms Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes drier.
Dry and warm conditions will last through much of next week, save for
a period in the mid-week where a slight increase in humidities
return. Further drying from the west is possible into next weekend
with near average temperatures and mostly clear skies.
&&
.DISCUSSION...
Building anticyclonic heights noted over the region both in the
evening RAOBs as well as long-framed regional radar loops, with
returns almost oriented on a northward moving concave arc from
Barstow, CA through the AZ White Mountains. Westerly mean and UL
flow has returned, with storm tops quickly being lofted
northeastward on this evening`s stronger storms. The SE CA and AZ
Lower Deserts will be in for several quiet days as several strong
Pacific troughs transition through the West Coast and Intermountain
West. Water vapor imagery overnight depicts three such trough
circulations landfalling or moving towards the West Coast. The
southern most is significantly dry through the mid and upper levels
over the L.A. Basin. Unseasonably strong westerly flow noted 500mb
and above, with a 50-55kt 300mb jet skirting across northern AZ later
tonight and into Monday, tied to the southern most shortwave. Loss of
our moisture advecting wind profile will allow for some thinning of
PWATs and LL dewpoints with daytime mixing, drawing them out of the
MMB richness. Resulting PoP forecasts save for some lingering PoPs on
the Rim for today, are well below climo and have nil chances for the
lower deserts and non-zero but still non-weather mentionable values
for the Zone 24/Southern Gila mountains. Under clear skies and fairly
typical winds, temperatures will settle out within range of early
July normals, 107F for Phoenix and Yuma both today and Monday. Subtle
variances in 1000-500mb thicknesses and a peak of 850mb temperatures
on Tuesday could support temperatures near 110F for the warmer
deserts, likely the warmest day but staying below excessive heat
thresholds.
More noticeable spread enters the temperature forecasts for Wednesday
and beyond, especially the morning lows, tied to the depth and
persistence of a mid-week moisture intrusion from the south. Up until
this point, the ML/UL high centers remained to our southeast over
Mexico. GFS model trends with the intrusion have been a bit drier the
last few nights, while the ECMWF remains a higher on the 850mb Td
fields for Wednesday and Thursday. Forecast streamlines through the
column struggle to take up anything with an easterly influence, with
850-700mb winds turning southerly for 24 hr window or so. While it`s
still a ways out, ample moisture over the Sierra Madre and inverted
wave movement along the Mexican Riviera and Baja Peninsula could
trigger some larger storm complexes that send outflow intrusions
northward, rather than our depending on easterly to southeasterly
advection flow. Resulting temperatures forecasts are rather steady
state and near seasonal normals, but any moisture insulation could
shave a few degrees off the limits on the diurnal range, more likely
for locations east of the CO River Valley. Slight storm chances enter
into SE AZ, the White Mtns and the Rim for Wednesday and some of the
mountainous locations of southern Gila county for Thursday afternoon.
With still modest westerly flow progged through the majority of the
column, conditions are not looking favorable for outflow intrusions
to make their way onto the desert floors at this time. Longwave
troughing remains over the West Coast for late this week and the
coming weekend with the potential for further dry advection from the
west. Zonal heights aloft over the Southwest should result in near
average temperatures, dry conditions for nearly all forecast locales
under mostly clear skies.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No aviation impacts through Monday morning under mostly clear skies.
Confidence is good that wind shifts/transition to an easterly
component overnight will occur later than typical, and similarly the
afternoon switch back to a westerly direction will occur earlier
than usual.
Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation impacts through Monday morning under clear skies. Sfc
winds will generally favor a south to southwest direction, though
some periods yielding a light and variable direction will be
possible towards sunrise.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Stronger than usual early July southwest flow across the region will
result in slightly above normal temperatures and generally dry
conditions. An increase in moisture Wednesday and Thursday could
lead to a few thunderstorms over higher terrain of southern Gila and
far eastern Maricopa/Pinal counties with little to no chance of
wetting rains elsewhere. With this drier pattern, afternoon minimum
humidity levels will fall back into a 10 to 20 percent range with
fair to good overnight recovery. Wind speeds will be somewhat
stronger than typical for early July with more frequent afternoon
gusts especially around higher terrain features.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Nolte
AVIATION...MO
FIRE WEATHER...MO/Hirsch
Area Forecast Discussion
National Weather Service Flagstaff AZ
352 AM MST SUN JUL 3 2016
.SYNOPSIS...Westerly flow across Arizona will bring drier and
warmer conditions to the area heading into next week.
&&
.DISCUSSION...
A drying westerly flow is going to take shape over the next
several days across northern Arizona. Precipitation chances will
generally be reduced to `slight` today, with chances confined to
the higher terrain of eastern AZ for Independence Day. Breezy
afternoons will take shape mid-week as well, with winds out of the
west-southwest. Warmer daytime temps can also be anticipated.
While slight chances for showers may return at times during the
coming week, the pattern looks typical for an extended monsoon
break through much of the 7-day forecast.
&&
.AVIATION...For the 12Z Package...Expect VFR conditions to prevail
over the next 24 hours. Isolated SHRA/TSRA possible 18Z-02Z
mainly over the higher terrain from Mogollon Rim and White Mtns
northward. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...A drier and more stable westerly flow will bring
decreasing shower and thunderstorm coverage to northern Arizona
today and Monday. Any isolated storms that develop today will move
from west to east.
Tuesday through Thursday...Westerly flow brings mainly dry
conditions with breezy afternoons. Temperatures near normal.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...KD
AVIATION...JJ
FIRE WEATHER...JJ
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Flagstaff AZ
352 AM MST SUN JUL 3 2016
.SYNOPSIS...Westerly flow across Arizona will bring drier and
warmer conditions to the area heading into next week.
&&
.DISCUSSION...
A drying westerly flow is going to take shape over the next
several days across northern Arizona. Precipitation chances will
generally be reduced to `slight` today, with chances confined to
the higher terrain of eastern AZ for Independence Day. Breezy
afternoons will take shape mid-week as well, with winds out of the
west-southwest. Warmer daytime temps can also be anticipated.
While slight chances for showers may return at times during the
coming week, the pattern looks typical for an extended monsoon
break through much of the 7-day forecast.
&&
.AVIATION...For the 12Z Package...Expect VFR conditions to prevail
over the next 24 hours. Isolated SHRA/TSRA possible 18Z-02Z
mainly over the higher terrain from Mogollon Rim and White Mtns
northward. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...A drier and more stable westerly flow will bring
decreasing shower and thunderstorm coverage to northern Arizona
today and Monday. Any isolated storms that develop today will move
from west to east.
Tuesday through Thursday...Westerly flow brings mainly dry
conditions with breezy afternoons. Temperatures near normal.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...KD
AVIATION...JJ
FIRE WEATHER...JJ
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Flagstaff AZ
352 AM MST SUN JUL 3 2016
.SYNOPSIS...Westerly flow across Arizona will bring drier and
warmer conditions to the area heading into next week.
&&
.DISCUSSION...
A drying westerly flow is going to take shape over the next
several days across northern Arizona. Precipitation chances will
generally be reduced to `slight` today, with chances confined to
the higher terrain of eastern AZ for Independence Day. Breezy
afternoons will take shape mid-week as well, with winds out of the
west-southwest. Warmer daytime temps can also be anticipated.
While slight chances for showers may return at times during the
coming week, the pattern looks typical for an extended monsoon
break through much of the 7-day forecast.
&&
.AVIATION...For the 12Z Package...Expect VFR conditions to prevail
over the next 24 hours. Isolated SHRA/TSRA possible 18Z-02Z
mainly over the higher terrain from Mogollon Rim and White Mtns
northward. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...A drier and more stable westerly flow will bring
decreasing shower and thunderstorm coverage to northern Arizona
today and Monday. Any isolated storms that develop today will move
from west to east.
Tuesday through Thursday...Westerly flow brings mainly dry
conditions with breezy afternoons. Temperatures near normal.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...KD
AVIATION...JJ
FIRE WEATHER...JJ
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Flagstaff AZ
352 AM MST SUN JUL 3 2016
.SYNOPSIS...Westerly flow across Arizona will bring drier and
warmer conditions to the area heading into next week.
&&
.DISCUSSION...
A drying westerly flow is going to take shape over the next
several days across northern Arizona. Precipitation chances will
generally be reduced to `slight` today, with chances confined to
the higher terrain of eastern AZ for Independence Day. Breezy
afternoons will take shape mid-week as well, with winds out of the
west-southwest. Warmer daytime temps can also be anticipated.
While slight chances for showers may return at times during the
coming week, the pattern looks typical for an extended monsoon
break through much of the 7-day forecast.
&&
.AVIATION...For the 12Z Package...Expect VFR conditions to prevail
over the next 24 hours. Isolated SHRA/TSRA possible 18Z-02Z
mainly over the higher terrain from Mogollon Rim and White Mtns
northward. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...A drier and more stable westerly flow will bring
decreasing shower and thunderstorm coverage to northern Arizona
today and Monday. Any isolated storms that develop today will move
from west to east.
Tuesday through Thursday...Westerly flow brings mainly dry
conditions with breezy afternoons. Temperatures near normal.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...KD
AVIATION...JJ
FIRE WEATHER...JJ
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Phoenix AZ
206 AM MST SUN JUL 3 2016
.SYNOPSIS...
Subtle drying transitioning in from the west will relegate the best
chances for afternoon and evening storms Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes drier.
Dry and warm conditions will last through much of next week, save for
a period in the mid-week where a slight increase in humidities
return. Further drying from the west is possible into next weekend
with near average temperatures and mostly clear skies.
&&
.DISCUSSION...
Building anticyclonic heights noted over the region both in the
evening RAOBs as well as long-framed regional radar loops, with
returns almost oriented on a northward moving concave arc from
Barstow, CA through the AZ White Mountains. Westerly mean and UL
flow has returned, with storm tops quickly being lofted
northeastward on this evening`s stronger storms. The SE CA and AZ
Lower Deserts will be in for several quiet days as several strong
Pacific troughs transition through the West Coast and Intermountain
West. Water vapor imagery overnight depicts three such trough
circulations landfalling or moving towards the West Coast. The
southern most is significantly dry through the mid and upper levels
over the L.A. Basin. Unseasonably strong westerly flow noted 500mb
and above, with a 50-55kt 300mb jet skirting across northern AZ later
tonight and into Monday, tied to the southern most shortwave. Loss of
our moisture advecting wind profile will allow for some thinning of
PWATs and LL dewpoints with daytime mixing, drawing them out of the
MMB richness. Resulting PoP forecasts save for some lingering PoPs on
the Rim for today, are well below climo and have nil chances for the
lower deserts and non-zero but still non-weather mentionable values
for the Zone 24/Southern Gila mountains. Under clear skies and fairly
typical winds, temperatures will settle out within range of early
July normals, 107F for Phoenix and Yuma both today and Monday. Subtle
variances in 1000-500mb thicknesses and a peak of 850mb temperatures
on Tuesday could support temperatures near 110F for the warmer
deserts, likely the warmest day but staying below excessive heat
thresholds.
More noticeable spread enters the temperature forecasts for Wednesday
and beyond, especially the morning lows, tied to the depth and
persistence of a mid-week moisture intrusion from the south. Up until
this point, the ML/UL high centers remained to our southeast over
Mexico. GFS model trends with the intrusion have been a bit drier the
last few nights, while the ECMWF remains a higher on the 850mb Td
fields for Wednesday and Thursday. Forecast streamlines through the
column struggle to take up anything with an easterly influence, with
850-700mb winds turning southerly for 24 hr window or so. While it`s
still a ways out...ample moisture over the Sierra Madre and inverted
wave movement along the Mexican Riviera and Baja Peninsula could
trigger some larger storm complexes that send outflow intrusions
northward, rather than our depending on easterly to southeasterly
advection flow. Resulting temperatures forecasts are rather steady
state and near seasonal normals, but any moisture insulation could
shave a few degrees off the limits on the diurnal range, more likely
for locations east of the CO River Valley. Slight storm chances enter
into SE AZ, the White Mtns and the Rim for Wednesday and some of the
mountainous locations of southern Gila county for Thursday afternoon.
With still modest westerly flow progged through the majority of the
column, conditions are not looking favorable for outflow intrusions
to make their way onto the desert floors at this time. Longwave
troughing remains over the West Coast for late this week and the
coming weekend with the potential for further dry advection from the
west. Zonal heights aloft over the Southwest should result in near
average temperatures, dry conditions for nearly all forecast locales
under mostly clear skies.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
A drier and more stable atmosphere is forecast to move into the
greater Phoenix area through Sunday evening. Therefore mostly clear
skies are forecast. Surface winds will be light easterly, becoming
west during the afternoons and evening generally under 10 knots.
Southeast California/Southwest Arizona including KIPL and KBLH:
A drier and more stable atmosphere is forecast to move into
the greater Phoenix area through Sunday evening. Mostly clear skies
are forecast, with steady south winds 8 to 15 knots.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Southwesterly flow between the monsoon high across northern Mexico
and low pressure across the Pacific Northwest will result in above
normal temperatures and generally dry conditions. An increase in
moisture is expected Wednesday as the high shifts eastward. Drier
westerly flow across southeastern California will then battle deeper
moisture across southeastern Arizona through the remainder of the
week, with showers and thunderstorms mainly relegated to southern and
eastern Arizona. Near normal temperatures are expected mid to late
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...Nolte
AVIATION...Vasquez
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Tucson AZ
200 AM MST SUN JUL 3 2016
.SYNOPSIS...Drier air moving into the region will significantly
reduce the amount of thunderstorms through Tuesday. The lack of
showers and cloud cover will allow for higher afternoon temperatures
as well. An increase in moisture the middle of next week will
increase the chances of showers and thunderstorms once again.
&&
.DISCUSSION...Water vapor imagery and 03/00Z upper-air plots show
nearly zonal flow across the Desert Southwest as Arizona lies
between high pressure over southern Chihuahua Mexico and a low
pressure system over central California. Plenty of dry mid level air
across the eastern Pacific waters and extending across northern
Baja, northwest Sonora Mexico and the southern two thirds of Arizona
and into New Mexico. The 03/00Z KTWC sounding showed significant
drying in the past 48 hours or so, with a PW of 1.2 inches compared
to 1.77 inches from Thursday afternoon. The 06Z GPS PW values from
the U of A indicate around 1.2 inches and the CIRA LPW total
indicates 1.1 inches. IR satellite imagery shows mostly clear skies
across much of Arizona at this time, with the exception being some
mid level clouds over eastern Sonora and northwest Chihuahua that
have spilled over into extreme southern Cochise county and parts
of Santa Cruz county.
As of 08Z (1 AM MST), temperatures ranged from the lower 70s to the
lower 80s which are generally around 5 to 8 degs warmer than 24
hours ago. Dewpoint temperatures range from the lower 50s to the mid
60s and these values range from 1 to 5 degs cooler/drier than 24
hours ago. As a result, relative humidity values range from 15 to 30
percent drier than this time yesterday.
Models indicate that the ridge to our south and west will build a
bit farther north and east today, becoming nearly overhead. This
will result in warmer afternoon temperatures through Tuesday as the
high remains in the same general area through that time. In
addition, expect a reduction in the threat for showers and
thunderstorms as well. Limited activity may occur today and Monday,
mostly over the White mountains and perhaps isolated activity over
southern parts of Cochise county on Tuesday. By Tuesday night into
Wednesday models indicate that return flow on the western flank of
the ridge will allow for an increase in moisture with PW`s generally
ranging from around 0.75-1.0 inches through Tuesday before climbing
back up to around 1.0-1.3 inches through early Thursday. Values will
then decrease again late in the week and into the weekend as drier
air gets ushered in from the west in response to an approaching
trough well to our northwest and north. This will once again result
in increasing daytime temperatures after a brief respite on
Wednesday and Thursday due to increasing moisture and the threat of
convection moderating temperatures a bit.
For Tucson, high temperatures will range from 2 to 4 degs below
normal today, then will hover within a degree or two either side of
normal for Monday through Friday. For next weekend, highs a few
degrees above normal. Low temperatures will range from 2 to 5 degs
above normal each morning, although the warmest mornings will occur
Wednesday and Thursday.
&&
.AVIATION...VALID THRU 04/12Z.
High pressure building in from west to east will bring more stable
conditions and mostly clear skies. Winds will generally be less than
10 kts through the period. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Drying trend is expected to start the new
week with little if any convection today through Tuesday. A brief
surge of moisture will bring some scattered showers and
thunderstorms Wednesday into Friday then we will dry out once again.
Winds will generally favor diurnal patterns, with some enhancement
in areas where afternoon northwest flow is the norm. Portions of
zone 152 could see afternoon gustiness greater than 20 mph in valley
locations Sunday through Tuesday.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
PUBLIC...Mollere
AVIATION/FIRE WEATHER...Cerniglia
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Flagstaff AZ
921 PM MST SAT JUL 2 2016
.SYNOPSIS...Sunday, drier westerly flow across Arizona will
bring drier and warmer conditions to the area heading into next
week.
&&
.DISCUSSION...The forecast was updated for the overnight time
period. The chance of precipitation was lowered to only isolated
showers and thunderstorms over southern Navajo and Apache counties
through midnight...then mainly dry after midnight.
&&
.PREV DISCUSSION /340 PM MST/...A somewhat linear convective
feature formed this afternoon along a convergence zone formed in
the wake of last nights outflow and a developing s/wv ridge to our
west. This feature is nearly aligned along the I-40 corridor,
which is problematic for travelers this afternoon.
After this evening, drier mid-level air and anticyclonic flow is
evident to our west on water vapor imagery. Additionally, warmer
temperatures aloft will develop through at least Monday with this
s/wv ridge.
At the same time, long wave troughing develops over the northwest
United States, providing a prolonged period of drier and stable
flow over the southwest. A brief intrusion of monsoon moisture may
return Wednesday or Thursday, but then right back to dry
westerlies heading into next weekend.
The net result is a period of mainly dry and warmer conditions
after today.
&&
.AVIATION...For the 06Z Package...Expect VFR conditions with a few
showers and thunderstorms on Sunday after 18Z mainly over the
mountain areas of the Mogollon Rim and Chuska Mountains. Shower
activity will diminish around 02Z. Aviation discussion not updated
for TAF amendments.
&&
.FIRE WEATHER...A drier and more stable westerly flow will bring
decreasing shower and thunderstorm coverage to northern Arizona.
Storm motion on Sunday will be from the west to the east.
Tuesday through thursday...Only daytime and isolated storms are
expected across ponderosa forests through the period as dry westerly
flow increases across the area. Elsewhere very dry with afternoon
minimum humidities belwo 15 percent.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...TC/Peterson
AVIATION...Bohlin
FIRE WEATHER...DL
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Phoenix AZ
830 PM MST SAT JUL 2 2016
.SYNOPSIS...
Subtle drying, transitioning in from the west will relegate the best
chances for afternoon and evening storms Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes
drier. Dry and warm conditions will last through much of next week,
save for a period in the mid-week where a slight increase in
humidities return.
&&
.DISCUSSION...
Anti-cyclonic mid/upper level flow, following the passing trof
yesterday/overnight stabilized the airmass in our forecast area
today. There were no aftn tstms, only stable cumulus clouds.
Additionally, upper air data showed the airmass had dried noticeably
from the west today, with the monsoon moisture boundary now
pushed into southeast AZ.
Anti-cyclonic winds aloft tomorrow and Monday, with unseasonably
warm mid level temperatures and additional moisture loss, should
provide dry and warmer weather over most of the forecast area.
Current dry and warmer forecasts look good. no updates planned.
.PREVIOUS DISCUSSION...135 PM MST...
Slightly drier and more anticyclonic flow aloft continued to spread
into central Arizona from the west early this afternoon in the wake
of a departing upper trof pushing east and into western New Mexico.
Surface dewpoints at 1 PM were still elevated and mostly ranged from
the mid 50s to low 60s, although they were trending downward and
were running 2 to 9 degrees lower than 24 hours ago. Despite
elevated moisture, the threat for thunderstorms this afternoon will
pretty much be confined to higher terrain areas east of Phoenix;
upper streamlines this afternoon will be slightly anticyclonic and
laminar with no significant deformation/difluence. With minimal upper
support we can expect some cumulus over the deserts - and we can see
that developing already on visible imagery - but that will be about
it convectively speaking. Early afternoon SPC mesoanalysis graphics
depicted CAPE over 1000 j/kg over the central deserts, but there was
a marked drying trend forecast with CAPE dropping noticeably from the
west as the afternoon progresses.
More prominent westerly flow aloft will develop as the ML/UL high
centers remain to our southeast over Mexico on Sunday through early
next week. Temperatures will gradually warm and return to normal
through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and
a return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
A drier and more stable atmosphere is forecast to move into the
greater Phoenix area through Sunday evening. Therefore mostly clear
skies are forecast. Surface winds will be light easterly, becoming
west during the afternoons and evening generally under 10 knots.
Southeast California/Southwest Arizona including KIPL and KBLH:
A drier and more stable atmosphere is forecast to move into
the greater Phoenix area through Sunday evening. Mostly clear skies
are forecast, with steady south winds 8 to 15 knots.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Southwesterly flow between the monsoon high across northern Mexico
and low pressure across the Pacific Northwest will result in above
normal temperatures and generally dry conditions. An increase in
moisture is expected Wednesday as the high shifts eastward. Drier
westerly flow across southeastern California will then battle deeper
moisture across southeastern Arizona through the remainder of the
week, with showers and thunderstorms mainly relegated to southern and
eastern Arizona. Near normal temperatures are expected mid to late
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/CB/Nolte
AVIATION...Vasquez
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Tucson AZ
821 PM MST SAT JUL 2 2016
.SYNOPSIS...Drier air moving into the region will significantly
reduce the amount of convection through Monday. The lack of showers
and cloud cover will allow for higher afternoon temperatures as
well. An increase in moisture the middle of next week will increase
the chances of showers and thunderstorms once again.
&&
.DISCUSSION...We have dried quite a bit in the past 36 hours,
with precipitable water values down to around 1 to 1.2 inches
across the area, and surface dew points generally in the 50s
(down 6 to 12 degrees over the past 24 hours). Even with the
drying trend, good instability allowed for several strong
thunderstorms southwest through southeast of Tucson over the past
few hours. With sunset things are quieting down.
The current forecast looks good with the downward trend in storms
to start the week. As this happens, we will heat back up to near
or above typical early July averages. Please see the previous
discussion below for additional details.
&&
.AVIATION...VALID THRU 04/06Z.
High pressure building in from west to east on the back side of a
mid-level trough will bring more stable conditions to start the
new week. Winds will generally be less than 10 kts with VFR
conditions throughout. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Drying trend is expected to start the new
week. Winds will generally favor diurnal patterns, with some
enhancement in areas where afternoon northwest flow is the norm.
Portions of zone 152 could see afternoon gustiness greater than 20
mph in valley locations Sunday through Tuesday.
&&
.PREV DISCUSSION...The drying trend will continue Sunday and
Monday as the ridge of high pressure aloft over Sonora and
Chihuahua shunts the deep moisture to our south and east with most
areas remaining dry. About the best we can hope for is a slight
chance of showers and thunderstorms mainly across the White
Mountains both days with the rest of the forecast area remaining
dry. Given the drier atmosphere, temperatures will will warm back
up to normal values by Monday and Tuesday. The ridge axis will be
far enough east on Tuesday to start a southerly flow of moisture
into far southeast Arizona. Thus, slight chances for showers and
thunderstorms are possible for the higher terrain and
international border area across Cochise County. The northward
push of moisture over the rest of the region is expected Wednesday
and Thursday with a more typical early July monsoon pattern then
before drier westerly flow returns for the end of the work week
and into next weekend as the mid/upper high pushes south of the
area again.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Meyer/Lader/Cantin
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Flagstaff AZ
340 PM MST SAT JUL 02 2016
.SYNOPSIS...Expect active monsoon weather into this evening. By
Sunday, drier westerly flow across Arizona will bring drier and
warmer conditions to the area heading into next week.
&&
.DISCUSSION...A somewhat linear convective feature formed this
afternoon along a convergence zone formed in the wake of last nights
outflow and a developing s/wv ridge to our west. This feature is
nearly aligned along the I-40 corridor, which is problematic for
travelers this afternoon.
After this evening, drier mid-level air and anticyclonic flow is
evident to our west on water vapor imagery. Additionally, warmer
temperatures aloft will develop through at least Monday with this
s/wv ridge.
At the same time, long wave troughing develops over the northwest
United States, providing a prolonged period of drier and stable flow
over the southwest. A brief intrusion of monsoon moisture may return
Wednesday or Thursday, but then right back to dry westerlies
heading into next weekend.
The net result is a period of mainly dry and warmer conditions after
today.
&&
.AVIATION...For the 00Z Package...until 03z Sun expect scattered
shra/tsra and isold +tsra along and north of the Mogollon Rim and
isolated coverage elsewhere. Strongest storms will contain mvfr/ifr
conditions and gusty winds. Showers and thunderstorms ending aft 03z
Sun. Aft 18z Sun isolated thunderstorm coverage for areas above 6500
feet with fair wx elsewhere. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...For Sunday and Monday, a drier and more stable
westerly flow will bring decreasing shower and thunderstorm coverage
to northern Arizona. Storm motion on Sunday will be from the west to
the east.
Tuesday through thursday...Only daytime and isolated storms are
expected across ponderosa forests through the period as dry westerly
flow increases across the area. Elsewhere very dry with afternoon
minimum humidities below 15 percent.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...Peterson
AVIATION...DL
FIRE WEATHER...DL
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Tucson AZ
200 PM MST SAT JUL 2 2016
.SYNOPSIS...Drier air moving into the region will significantly
reduce the amount of convection through Monday. The lack of showers
and cloud cover will allow for higher afternoon temperatures as
well. An increase in moisture the middle of next week will increase
the chances of showers and thunderstorms once again.
&&
.DISCUSSION...The atmosphere is starting to dry out with GPS pwat
values down to 1 inch to 1.25 inches across southeast Arizona as
ridging builds in and drier air aloft is mixing down. There were a
few showers and thunderstorms briefly this morning that formed along
the higher terrain southeast of Tucson but those quickly faded away
as they moved off the mountains with just a few light showers
redeveloping in the last half hour. One shower did pass over Sierra
Vista with one gauge recorded a half inch this morning. Have trended
pops downward this afternoon but will still depict a slight chance
of a shower or thunderstorm south and east of Tucson into early this
evening.
The drying trend will continue Sunday and Monday as the ridge of
high pressure aloft over Sonora and Chihuahua shunts the deep
moisture to our south and east with most areas remaining dry. About
the best we can hope for is a slight chance of showers and
thunderstorms mainly across the White Mountains both days with the
rest of the forecast area remaining dry. Given the drier atmosphere,
temperatures will will warm back up to normal values by Monday and
Tuesday. The ridge axis will be far enough east on Tuesday to start
a southerly flow of moisture into far southeast Arizona. Thus,
slight chances for showers and thunderstorms are possible for the
higher terrain and international border area across Cochise County.
The northward push of moisture over the rest of the region is
expected Wednesday and Thursday with a more typical early July
monsoon pattern then before drier westerly flow returns for the end
of the work week and into next weekend as the mid/upper high pushes
south of the area again.
&&
.AVIATION...VALID THRU 04/00Z.
High pressure building in from west to east on the back side of a
mid-level trough will bring stable conditions this afternoon into
early next week. Winds will generally be less than 10 kts with VFR
conditions throughout. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Drying trend is expected through early next week.
Winds will generally favor diurnal patterns, with some enhancement
in areas where afternoon northwest flow is the norm. Portions of
zone 152 could see afternoon gustiness greater than 20 mph in valley
locations Sunday through Tuesday.
&&
.TWC Watches/Warnings/Advisories...None.
&&
$$
Public...GL
Aviation/Fire Weather...Cantin
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Phoenix AZ
135 PM MST SAT JUL 2 2016
.SYNOPSIS...
A combination of lingering monsoon moisture and weather disturbances
moving eastward across the Desert Southwest will bring chances for
showers and thunderstorms through this evening over higher terrain
areas east of Phoenix. Subtle drying transitioning in from the west
will relegate the best chances for afternoon and evening storms
Sunday over the higher terrain of eastern Arizona, mainly east of
Globe. High temperatures will steadily climb into the weekend and
early next week as the atmosphere becomes drier. Dry and warm
conditions will last through much of next week, save for a period in
the mid-week where a slight increase in humidities return.
&&
.DISCUSSION...
Slightly drier and more anticyclonic flow aloft continued to spread
into central Arizona from the west early this afternoon in the wake
of a departing upper trof pushing east and into western New Mexico.
Surface dewpoints at 1 PM were still elevated and mostly ranged from
the mid 50s to low 60s, although they were trending downward and
were running 2 to 9 degrees lower than 24 hours ago. Despite
elevated moisture, the threat for thunderstorms this afternoon will
pretty much be confined to higher terrain areas east of Phoenix;
upper streamlines this afternoon will be slightly anticyclonic and
laminar with no significant deformation/difluence. With minimal upper
support we can expect some cumulus over the deserts - and we can see
that developing already on visible imagery - but that will be about
it convectively speaking. Early afternoon SPC mesoanalysis graphics
depicted CAPE over 1000 j/kg over the central deserts, but there was
a marked drying trend forecast with CAPE dropping noticeably from the
west as the afternoon progresses.
More prominent westerly flow aloft will develop as the ML/UL high
centers remain to our southeast over Mexico on Sunday through early
next week. Temperatures will gradually warm and return to normal
through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and
a return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No thunderstorms are forecast for the greater Phoenix area today,
but mountain thunderstorms to the east are still expected, especially
this afternoon. Wind speeds of 12 kts or less and fairly typical diurnal
switches are likely. Very slim chance of any outflows from mountain
storms to affect area terminals.
Southeast California/Southwest Arizona including KIPL and KBLH:
Generally clear skies through Sunday. Winds will be breezy during the
afternoon at KBLH following consistent southerly directions. Wind
speeds at KIPL will mostly fall between 8-12 kts with southeasterly
directions until early this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Southwesterly flow between the monsoon high across northern Mexico
and low pressure across the Pacific Northwest will result in above
normal temperatures and generally dry conditions. An increase in
moisture is expected Wednesday as the high shifts eastward. Drier
westerly flow across southeastern California will then battle deeper
moisture across southeastern Arizona through the remainder of the
week, with showers and thunderstorms mainly relegated to southern and
eastern Arizona. Near normal temperatures are expected mid to late
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...CB/Nolte
AVIATION...Kuhlman
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Phoenix AZ
135 PM MST SAT JUL 2 2016
.SYNOPSIS...
A combination of lingering monsoon moisture and weather disturbances
moving eastward across the Desert Southwest will bring chances for
showers and thunderstorms through this evening over higher terrain
areas east of Phoenix. Subtle drying transitioning in from the west
will relegate the best chances for afternoon and evening storms
Sunday over the higher terrain of eastern Arizona, mainly east of
Globe. High temperatures will steadily climb into the weekend and
early next week as the atmosphere becomes drier. Dry and warm
conditions will last through much of next week, save for a period in
the mid-week where a slight increase in humidities return.
&&
.DISCUSSION...
Slightly drier and more anticyclonic flow aloft continued to spread
into central Arizona from the west early this afternoon in the wake
of a departing upper trof pushing east and into western New Mexico.
Surface dewpoints at 1 PM were still elevated and mostly ranged from
the mid 50s to low 60s, although they were trending downward and
were running 2 to 9 degrees lower than 24 hours ago. Despite
elevated moisture, the threat for thunderstorms this afternoon will
pretty much be confined to higher terrain areas east of Phoenix;
upper streamlines this afternoon will be slightly anticyclonic and
laminar with no significant deformation/difluence. With minimal upper
support we can expect some cumulus over the deserts - and we can see
that developing already on visible imagery - but that will be about
it convectively speaking. Early afternoon SPC mesoanalysis graphics
depicted CAPE over 1000 j/kg over the central deserts, but there was
a marked drying trend forecast with CAPE dropping noticeably from the
west as the afternoon progresses.
More prominent westerly flow aloft will develop as the ML/UL high
centers remain to our southeast over Mexico on Sunday through early
next week. Temperatures will gradually warm and return to normal
through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and
a return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No thunderstorms are forecast for the greater Phoenix area today,
but mountain thunderstorms to the east are still expected, especially
this afternoon. Wind speeds of 12 kts or less and fairly typical diurnal
switches are likely. Very slim chance of any outflows from mountain
storms to affect area terminals.
Southeast California/Southwest Arizona including KIPL and KBLH:
Generally clear skies through Sunday. Winds will be breezy during the
afternoon at KBLH following consistent southerly directions. Wind
speeds at KIPL will mostly fall between 8-12 kts with southeasterly
directions until early this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Southwesterly flow between the monsoon high across northern Mexico
and low pressure across the Pacific Northwest will result in above
normal temperatures and generally dry conditions. An increase in
moisture is expected Wednesday as the high shifts eastward. Drier
westerly flow across southeastern California will then battle deeper
moisture across southeastern Arizona through the remainder of the
week, with showers and thunderstorms mainly relegated to southern and
eastern Arizona. Near normal temperatures are expected mid to late
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...CB/Nolte
AVIATION...Kuhlman
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Phoenix AZ
1249 PM MST SAT JUL 2 2016
.UPDATE...Updated Fire Weather Discussion.
&&
.SYNOPSIS...
A combination of lingering monsoon moisture and weather disturbances
moving eastward across the Desert Southwest will bring chances for
showers and thunderstorms early today from Phoenix eastward. Subtle
drying transitioning in from the west will relegate the best chances
for afternoon and evening storms today and Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes drier.
Dry and warm conditions will last through much of next week, save for
a period in the mid-week where a slight increase in humidities return.
&&
.DISCUSSION...
At 9 am this morning, MCS associated with a passing short wave
continued to dissipate as it passed by to the northeast of Phoenix,
mostly grazing the border of our far eastern CWA as a few
showers/storms moved past Roosevelt and to the north of Globe. IR
imagery showed sunny skies from Phoenix west, and the 12z 500mb plot
indicated pronounced anticyclonic curvature over western AZ/SERN CA
behind the exiting trof. Of course, low level moisture over south
central AZ remains elevated this morning, with 1.57 inches of PWAT
at Phoenix and central desert dewpoints in the upper 50s to mid 60s.
However, we look to be moving into a drying phase of the monsoon
starting today and heading into the first part of next week as
westerly flow aloft and deeper westerly steering flow looks to
dominate the weather pattern for Arizona. For the rest of today we
should see mostly sunny skies west of Phoenix with some afternoon
cumulus in the area, and we will see a continued chance of afternoon
storms over the higher terrain northeast of Phoenix, although any
storm that forms will head off quickly towards the east/northeast.
Rain chances in the Phoenix area will be slim this afternoon, around
10 percent at best and most areas mostly likely will not see any
convection. West/southwest steering flow is always very detrimental
to storm chances in the greater Phoenix area and with ridging moving
in from the west, chances are even slimmer than normal. Current
forecasts look to be in good shape.
.PREVIOUS DISCUSSION...
Monsoon 2016 is off to an interesting start. Outside of our
exceptional heat events typical of this time of year (which
themselves produced rare upper teen to 120F values at some locales),
an earlier-than-climatologically-usual onset of the MMB intrusion,
record-breaking late June PWAT values, dewpoints and cloudiness more
typical of August and an upper trough and shear profile usually seen
as a season-ending event have made for an busy season kick-off!
Cyclonic trough flow across northern and south-central AZ still
noted on model forecasts, RAOBs from earlier in the evening and a few
ACARS soundings. Satellite derived winds and ACARS soundings indicate
anticyclonic flow is beginning to transition further up through the
atmo profile over portions of the southern CO River Valley. UL
divergence and still rich Monsoonal moisture surface (PWAT axis of
values 1.5 inches or greater extends from Vegas southeastward through
portions of Maricopa County) remains, where thunderstorm activity
continues overnight and is lighting up area radar scopes. Until the
weak troughing and PVU fully exit the CWA later today, enough CAPE
lingers within the turbulent mean flow to support isolated shower and
thunderstorm activity through the early afternoon from Phoenix
eastward (also in locations that mainly missed out on Friday
afternoon`s excitement and atmo turning over). Southeast CA
observation sites have observed a steady decrease in moisture values
beginning Friday afternoon, with dewpoints running 3 to 5 degrees
drier over the last few hours compared to this time early Friday.
Upper troughing along with the cooler 500mb temperatures and storm-
supportive ML lapse rates will exit to our northeast as a more stable
upper air pattern builds in from west-southwest by this evening. LL
mixing ratios do not complete dry out and remain deep enough to
support evening precip activity over the eastern AZ mountains
Saturday and Sunday. More prominent westerly flow aloft will develop
as the ML/UL high centers remain to our southeast over Mexico through
early next week. Temperatures will gradually warm and return to
normal through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and a
return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No thunderstorms are forecast for the greater Phoenix area today,
but mountain thunderstorms to the east are still expected, especially
this afternoon. Wind speeds of 12 kts or less and fairly typical diurnal
switches are likely. Very slim chance of any outflows from mountain
storms to affect area terminals.
Southeast California/Southwest Arizona including KIPL and KBLH:
Generally clear skies through Sunday. Winds will be breezy during the
afternoon at KBLH following consistent southerly directions. Wind
speeds at KIPL will mostly fall between 8-12 kts with southeasterly
directions until early this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday:
Southwesterly flow between the monsoon high across northern Mexico
and low pressure across the Pacific Northwest will result in above
normal temperatures and generally dry conditions. An increase in
moisture is expected Wednesday as the high shifts eastward. Drier
westerly flow across southeastern California will then battle deeper
moisture across southeastern Arizona through the remainder of the
week, with showers and thunderstorms mainly relegated to southern and
eastern Arizona. Near normal temperatures are expected mid to late
week.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...CB
PREVIOUS DISCUSSION...Nolte
AVIATION...Kuhlman
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Flagstaff AZ
955 AM MST SAT JUL 02 2016
.SYNOPSIS...Expect active monsoon weather again today. Starting
Sunday, drier westerly flow across Arizona will bring a downturn
in activity heading into next week.
&&
.DISCUSSION...Long lived gravity wave/outflow/decaying MCS from
Nevada last night has finally exited our eastern border. Behind
this wave, subsidence and building hghts will limit convective
development today, despite decent moisture profiles. Our current
POPs may be a little high, but they are in the ballpark.
After today, drier and stable westerly flow will take over for the
remainder of the holiday weekend and into next week. Expect fair and
seasonably warm conditions as a result.
Zones/grids look good, no updates needed.
&&
.AVIATION...For the 18Z Package...until 03z Sun expect scattered
shra/tsra and isold +tsra across northern Arizona, then decreasing
coverage. Strongest storms will contain mvfr/ifr conditions and
gusty winds. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Scattered showers and thunderstorms are expected to
persist again today, with only a few isolated storms on Sunday as
drier air filters into the area. Storm motion will be from the west
to the east.
Monday through Wednesday...Only a few isolated storms are expected
through the period over the higher terrain as dry westerly flow
develops across the area.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...Peterson
AVIATION...DL
FIRE WEATHER...JJ
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Phoenix AZ
925 AM MST SAT JUL 2 2016
.SYNOPSIS...
A combination of lingering monsoon moisture and weather disturbances
moving eastward across the Desert Southwest will bring chances for
showers and thunderstorms early today from Phoenix eastward. Subtle
drying transitioning in from the west will relegate the best chances
for afternoon and evening storms today and Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes drier.
Dry and warm conditions will last through much of next week, save for
a period in the mid-week where a slight increase in humidities return.
&&
.DISCUSSION...
At 9 am this morning, MCS associated with a passing short wave
continued to dissipate as it passed by to the northeast of Phoenix,
mostly grazing the border of our far eastern CWA as a few
showers/storms moved past Roosevelt and to the north of Globe. IR
imagery showed sunny skies from Phoenix west, and the 12z 500mb plot
indicated pronounced anticyclonic curvature over western AZ/SERN CA
behind the exiting trof. Of course, low level moisture over south
central AZ remains elevated this morning, with 1.57 inches of PWAT
at Phoenix and central desert dewpoints in the upper 50s to mid 60s.
However, we look to be moving into a drying phase of the monsoon
starting today and heading into the first part of next week as
westerly flow aloft and deeper westerly steering flow looks to
dominate the weather pattern for Arizona. For the rest of today we
should see mostly sunny skies west of Phoenix with some afternoon
cumulus in the area, and we will see a continued chance of afternoon
storms over the higher terrain northeast of Phoenix, although any
storm that forms will head off quickly towards the east/northeast.
Rain chances in the Phoenix area will be slim this afternoon, around
10 percent at best and most areas mostly likely will not see any
convection. West/southwest steering flow is always very detrimental
to storm chances in the greater Phoenix area and with ridging moving
in from the west, chances are even slimmer than normal. Current
forecasts look to be in good shape.
.PREVIOUS DISCUSSION...
Monsoon 2016 is off to an interesting start. Outside of our
exceptional heat events typical of this time of year (which
themselves produced rare upper teen to 120F values at some locales),
an earlier-than-climatologically-usual onset of the MMB intrusion,
record-breaking late June PWAT values, dewpoints and cloudiness more
typical of August and an upper trough and shear profile usually seen
as a season-ending event have made for an busy season kick-off!
Cyclonic trough flow across northern and south-central AZ still
noted on model forecasts, RAOBs from earlier in the evening and a few
ACARS soundings. Satellite derived winds and ACARS soundings indicate
anticyclonic flow is beginning to transition further up through the
atmo profile over portions of the southern CO River Valley. UL
divergence and still rich Monsoonal moisture surface (PWAT axis of
values 1.5 inches or greater extends from Vegas southeastward through
portions of Maricopa County) remains, where thunderstorm activity
continues overnight and is lighting up area radar scopes. Until the
weak troughing and PVU fully exit the CWA later today, enough CAPE
lingers within the turbulent mean flow to support isolated shower and
thunderstorm activity through the early afternoon from Phoenix
eastward (also in locations that mainly missed out on Friday
afternoon`s excitement and atmo turning over). Southeast CA
observation sites have observed a steady decrease in moisture values
beginning Friday afternoon, with dewpoints running 3 to 5 degrees
drier over the last few hours compared to this time early Friday.
Upper troughing along with the cooler 500mb temperatures and storm-
supportive ML lapse rates will exit to our northeast as a more stable
upper air pattern builds in from west-southwest by this evening. LL
mixing ratios do not complete dry out and remain deep enough to
support evening precip activity over the eastern AZ mountains
Saturday and Sunday. More prominent westerly flow aloft will develop
as the ML/UL high centers remain to our southeast over Mexico through
early next week. Temperatures will gradually warm and return to
normal through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and a
return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No thunderstorms are forecast for the greater Phoenix area today,
but mountain thunderstorms to the east are still expected, especially
this afternoon. Wind speeds of 12 kts or less and fairly typical diurnal
switches are likely. Very slim chance of any outflows from mountain
storms to affect area terminals.
Southeast California/Southwest Arizona including KIPL and KBLH:
Generally clear skies through Sunday. Winds will be breezy during the
afternoon at KBLH following consistent southerly directions. Wind
speeds at KIPL will mostly fall between 8-12 kts with southeasterly
directions until early this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Monday through Friday: The monsoon high will rebuild across
southeastern Arizona Monday, resulting in above normal temperatures
and generally dry conditions. An increase in moisture is expected
Wednesday as the high shifts eastward. Drier westerly flow across
southeastern California will battle deeper moisture across
southeastern Arizona through the remainder of the week, with showers
and thunderstorms mainly relegated to southern and eastern Arizona.
Near normal temperatures are expected mid to late 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...CB
PREVIOUS DISCUSSION...Nolte
AVIATION...Kuhlman
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Phoenix AZ
925 AM MST SAT JUL 2 2016
.SYNOPSIS...
A combination of lingering monsoon moisture and weather disturbances
moving eastward across the Desert Southwest will bring chances for
showers and thunderstorms early today from Phoenix eastward. Subtle
drying transitioning in from the west will relegate the best chances
for afternoon and evening storms today and Sunday over the higher
terrain of eastern Arizona. High temperatures will steadily climb
into the weekend and early next week as the atmosphere becomes drier.
Dry and warm conditions will last through much of next week, save for
a period in the mid-week where a slight increase in humidities return.
&&
.DISCUSSION...
At 9 am this morning, MCS associated with a passing short wave
continued to dissipate as it passed by to the northeast of Phoenix,
mostly grazing the border of our far eastern CWA as a few
showers/storms moved past Roosevelt and to the north of Globe. IR
imagery showed sunny skies from Phoenix west, and the 12z 500mb plot
indicated pronounced anticyclonic curvature over western AZ/SERN CA
behind the exiting trof. Of course, low level moisture over south
central AZ remains elevated this morning, with 1.57 inches of PWAT
at Phoenix and central desert dewpoints in the upper 50s to mid 60s.
However, we look to be moving into a drying phase of the monsoon
starting today and heading into the first part of next week as
westerly flow aloft and deeper westerly steering flow looks to
dominate the weather pattern for Arizona. For the rest of today we
should see mostly sunny skies west of Phoenix with some afternoon
cumulus in the area, and we will see a continued chance of afternoon
storms over the higher terrain northeast of Phoenix, although any
storm that forms will head off quickly towards the east/northeast.
Rain chances in the Phoenix area will be slim this afternoon, around
10 percent at best and most areas mostly likely will not see any
convection. West/southwest steering flow is always very detrimental
to storm chances in the greater Phoenix area and with ridging moving
in from the west, chances are even slimmer than normal. Current
forecasts look to be in good shape.
.PREVIOUS DISCUSSION...
Monsoon 2016 is off to an interesting start. Outside of our
exceptional heat events typical of this time of year (which
themselves produced rare upper teen to 120F values at some locales),
an earlier-than-climatologically-usual onset of the MMB intrusion,
record-breaking late June PWAT values, dewpoints and cloudiness more
typical of August and an upper trough and shear profile usually seen
as a season-ending event have made for an busy season kick-off!
Cyclonic trough flow across northern and south-central AZ still
noted on model forecasts, RAOBs from earlier in the evening and a few
ACARS soundings. Satellite derived winds and ACARS soundings indicate
anticyclonic flow is beginning to transition further up through the
atmo profile over portions of the southern CO River Valley. UL
divergence and still rich Monsoonal moisture surface (PWAT axis of
values 1.5 inches or greater extends from Vegas southeastward through
portions of Maricopa County) remains, where thunderstorm activity
continues overnight and is lighting up area radar scopes. Until the
weak troughing and PVU fully exit the CWA later today, enough CAPE
lingers within the turbulent mean flow to support isolated shower and
thunderstorm activity through the early afternoon from Phoenix
eastward (also in locations that mainly missed out on Friday
afternoon`s excitement and atmo turning over). Southeast CA
observation sites have observed a steady decrease in moisture values
beginning Friday afternoon, with dewpoints running 3 to 5 degrees
drier over the last few hours compared to this time early Friday.
Upper troughing along with the cooler 500mb temperatures and storm-
supportive ML lapse rates will exit to our northeast as a more stable
upper air pattern builds in from west-southwest by this evening. LL
mixing ratios do not complete dry out and remain deep enough to
support evening precip activity over the eastern AZ mountains
Saturday and Sunday. More prominent westerly flow aloft will develop
as the ML/UL high centers remain to our southeast over Mexico through
early next week. Temperatures will gradually warm and return to
normal through the weekend under mostly clear skies. Shortwave 500mb
ridging will peak temperatures Tuesday, allowing for temperatures to
flirt with 110F readings in the warmer desert locales, including
Phoenix, El Centro and Tacna. Migration of the 700-500mb high center
back towards New Mexico for Wednesday allows for southerly flow and a
return of monsoonal moisture into the area late Wednesday and
Thursday. This intrusion still looks to be a glancing shot of
moisture, as further drying is progged to advect in from the West
possibly by next weekend. Some slight chance coverage was maintained
for the mountainous locations, with the lower desert locales with
PoPs sub-10 or even sub-5 percent for the end of next week/early
weekend.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL:
No thunderstorms are forecast for the greater Phoenix area today,
but mountain thunderstorms to the east are still expected, especially
this afternoon. Wind speeds of 12 kts or less and fairly typical diurnal
switches are likely. Very slim chance of any outflows from mountain
storms to affect area terminals.
Southeast California/Southwest Arizona including KIPL and KBLH:
Generally clear skies through Sunday. Winds will be breezy during the
afternoon at KBLH following consistent southerly directions. Wind
speeds at KIPL will mostly fall between 8-12 kts with southeasterly
directions until early this evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Monday through Friday: The monsoon high will rebuild across
southeastern Arizona Monday, resulting in above normal temperatures
and generally dry conditions. An increase in moisture is expected
Wednesday as the high shifts eastward. Drier westerly flow across
southeastern California will battle deeper moisture across
southeastern Arizona through the remainder of the week, with showers
and thunderstorms mainly relegated to southern and eastern Arizona.
Near normal temperatures are expected mid to late 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...CB
PREVIOUS DISCUSSION...Nolte
AVIATION...Kuhlman
FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Tucson AZ
817 AM MST SAT JUL 2 2016
.SYNOPSIS...Drier air moving into the region will significantly
reduce the amount of convection expected today with little if any
expected Sunday and Monday. The lack of showers and cloud cover will
allow for higher afternoon temperatures as well. An increase in
moisture the middle of next week will increase the chances of showers
and thunderstorms once again.
&&
.DISCUSSION...Latest IR/WV imagery shows mostly clear skies from
Tucson south and westward with partly to mostly cloudy skies north
and east of Tucson. A few showers and thunderstorms are now
occurring over the Upper Gila River Valley near Safford but these
are gradually weakening. Meanwhile, a weakening forward propagating
MCS over north/central Arizona continues to move towards the White
Mountains this morning which may result in a few thunderstorms
across northern Graham and Greenlee counties later this morning. For
the rest of the area, the mid and upper levels have dried out
considerably but boundary layer moisture remains adequate with PWAT
values of 1.25 to 1.5 inches. Latest HRRR runs and UofA WRF NAM/GFS
show just enough boundary layer moisture for isolated to scattered
thunderstorms from the Tucson area south and eastward today. With
ridging building in, the storms should generally struggle so we
aren`t expecting significant impacts, but brief heavy rain is
possible.
The drying trend will continue Sunday and Monday as the ridge of
high pressure aloft over Sonora shunts the deep moisture to our
south and east with most areas remaining dry and otherwise just a
slight chance of showers and thunderstorms mainly across the White
Mountains. With ridging building in, temperatures will warm back up
to near normal values by Monday and Tuesday. The ridge axis will be
far enough east on Tuesday to start a southerly flow of moisture
into southeast Arizona. Thus, slight chances for showers and
thunderstorms are possible for the higher terrain and international
border then. The northward push of moisture over the rest of the
region is expected Wednesday and Thursday with a more typical early
July monsoon pattern then before drier westerly flow returns for the
end of the work week and into next weekend.
&&
.AVIATION...VALID THRU 03/18Z.
Considerably fewer showers and thunderstorms today, mainly for areas
south and east of Tucson. Mostly clear skies this morning for the
terminals, but during the afternoon hours, ceilings generally 10-15K
ft. Gusty winds and brief MVFR conditions in heavy rainfall are
likely near storms where wind gusts could exceed 30 kts. Otherwise
surface winds generally 10 kts or less. Aviation discussion not
updated for TAF amendments.
&&
.FIRE WEATHER...Moisture will begin to diminish across the region
beginning today and continuing through Tuesday, resulting in a
decrease in the coverage of showers and thunderstorms and a slight
bump up in afternoon temperatures. Some moisture will begin to
return to the area Wednesday for a general increase in showers and
thunderstorms once again.
&&
.TWC Watches/Warnings/Advisories...None.
&&
$$
GL
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
AREA FORECAST DISCUSSION
National Weather Service Northern Indiana
654 PM EDT SUN JUL 3 2016
.SYNOPSIS...
Issued at 650 PM EDT Sun Jul 3 2016
A stationary front to our south will gradually work north into
southern Indiana on Monday as a wave of low pressure rides along
the front. This may bring a few showers to locations south of the
highway 24 corridor Monday. Otherwise mostly cloudy skies will
persist across the area. Low temperatures tonight will be in the
upper 50s and 60s. Monday high temperatures will be in the mid to
upper 70s.
&&
.SHORT TERM...(This Evening through Monday)
Issued at 353 PM EDT Sun Jul 3 2016
A stationary front was near the Ohio River with a large are of rain
north of the front across Illinois into Indiana and Ohio. Rain
cooled air north of the front had accentuated the thermal boundary
with afternoon temperatures only in low to mid 60s where rain and
storms were occurring from central Illinois to central Indiana.
Surface based CAPEs had risen above 3000 J/Kg per SPC meso analysis
south of the front near the Ohio River where storms should intensify
later this afternoon. The GFS was generating too much precipitation
in the northern portion of the area of rain. Thunderstorms were
limited to the far southern edge of the area of rain where the
airmass was move favorable for convection. Have removed thunder from
this afternoon and this evening. The best chance for thunder will be
when a weak wave tries to lift north along the surface boundary. It
looks like the chance for heavy rain is low, although precipitable
water values should exceed 2.0 inches over far south and southeast
areas including Marion and Lima. Widespread conviction near the Ohio
River will limit north transport of moisture.
&&
.LONG TERM...(Monday Night through Sunday)
Issued at 353 PM EDT Sun Jul 3 2016
The upper air flow should become west/southwest aloft later this
week and allow short wave energy to move across the area as a
longwave trof amplifies along the west CONUS. This pattern should
allow the front to lift north across the area allowing very warm and
humid conditions Wednesday through Friday. There is a good chance
for thunderstorms during this period as precipitable water values
approach or exceed 2.0 inches. Highs between 85 and 90 degrees will
render heat indices in the 90s Wednesday through Friday. Cooler and
less humid air will return this coming weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 650 PM EDT Sun Jul 3 2016
Poor confidence fcst continues this pd as terminals lie well
north of active stnry fntl bndry through cntrl KY. Wk slab ascent
aloft overhead generating copious cloud cover yet cutoff fm a more
sig swd trailing mstr feed as stg convn conts ewd south of the OH
rvr. Thus as dry erly flw through the bndry lyr persists this
evening xpc vfr conds will cont to manifest.
Lt tonight/Mon am guidance still indicates a more vigorous ll mstr
feed working up invof the terminals w/cross sections indicative of
mvfr cig dvlpmnt which attm is not far away fm cntrl IL - cntrl IN
and of which may indeed bleed nwd overnight and retained prior
idea of a lwr cig grouping Mon am. Will reaccess as new 00Z model
guidance comes in ltr this evening.
&&
.IWX Watches/Warnings/Advisories...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...T
SHORT TERM...Skipper
LONG TERM...Skipper
AVIATION...T
Visit us at www.weather.gov/iwx
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[top]
Area Forecast Discussion
National Weather Service Indianapolis IN
646 PM EDT SUN JUL 3 2016
.UPDATE...
The AVIATION Section has been updated below.
&&
.SYNOPSIS...
Issued at 300 PM EDT Sun Jul 3 2016
A front and areas of low pressure will keep chances for rain, some
of it heavy, across central Indiana through Independence Day. After
a brief break Tuesday, rain chances return Wednesday into next
weekend for most of the area with very warm and humid air in place.
&&
.NEAR TERM.../Rest of This Afternoon and Tonight/
Issued at 300 PM EDT Sun Jul 3 2016
An upper level wave is producing widespread rain across much of
central and eastern Illinois into the northern half of central
Indiana at the moment. Some of the storms, across southern Illinois,
had heavy rain. The wave and its associated rain will continue to
push east across central Indiana for the remainder of the afternoon.
Will continue high PoPs through the afternoon over the area.
Focus then shifts to chances for rain overnight. An area of low
pressure will move east into the area along a warm front. The front
will move a little farther north into the area. There will be some
broad forcing with decent isentropic lift and the area will be close
to the right entrance region of an upper jet. In addition, there
will be some frontogenetic forcing as well.
Moisture will continue to be plentiful with precipitable water
values near 2 inches. Thus feel heavy rain is still a threat,
especially with frontogenetical forcing in play.
However, several models have shifted south once again with the heavy
rain axis. Some take this to an extreme. For example, the high-res
short term models hardly have any rain at all across the northern
forecast area after 00Z (with support from the 12Z GFS). While
cannot rule out a quick cutoff of rain somewhere across the forecast
area, am not ready to cut back PoPs north wholesale given the
expected forcing across the area.
Thus went likely PoPs north and categorical PoPs south tonight. Even
though went categorical, cut back the highest PoPs to the far south
where better confidence exists.
Given the above will keep Flash Flood Watch as is for now, although
feel the highest threat will be in the southern part of the area.
&&
.SHORT TERM.../Monday through Wednesday/
Issued at 300 PM EDT Sun Jul 3 2016
Focus remains on chances for rain through the period.
The front remains in the area along with another wave of low
pressure. Best forcing will remain closer to the front in the
southern and eastern forecast area. Will go likely or low
categorical PoPs there with only chance PoPs across the far
northwest. Moisture remains plentiful so the Flash Flood Watch still
looks good during the day Monday.
For Monday night, the system will be pulling off to the east, so
only went slight chance PoPs far northwest to chance PoPs elsewhere.
Gradually diminished PoPs through the night from northwest to
southeast as the system exits.
Brief ridging will build in on Tuesday keeping the area dry. An
upper wave will bring more chances for rain starting overnight
Tuesday night in the west and all areas on Wednesday. Went high
chance PoPs all areas by Wednesday afternoon given plenty of
instability and moisture to work with as the wave moves in.
Generally stayed with a blend of MOS and raw model output for
temperatures through the period.
&&
.LONG TERM /Wednesday Night through Sunday/...
Issued at 300 PM EDT Sun Jul 3 2016
Model Ensembles indicate a flat upper ridge over the deep south and
a series of upper disturbances riding along the top of the ridge
across our region from Wednesday night through Friday evening.
This will result in a good chance of thunderstorms across our
region.
A weak cold front will push south across Indiana Friday night and
stall across kentucky over the weekend as weak high pressure builds
into the great lakes. The 12Z EURO is mostly dry over the
weekend...while the GFS brings a couple of weak disturbances across
southern Indiana and Ohio valley. Kept a slight chance of
thunderstorms central and south over the weekend due to model
uncertainty...while the north will be mostly dry Saturday night on.
Model Blend indicate it will be humid with slightly above normal
temperatures through Friday and a little less humid with near normal
temperatures over the weekend.
&&
.AVIATION /Discussion for 04/0000 TAF Issuance/...
Issued at 637 PM EDT Sun Jul 3 2016
A quasistationary front lies across southern IN/northern KY this
evening resulting in MVFR and occasional IFR conditions. Due to
the amount of rain and cool temperatures this evening, expect low
clouds/fog across all TAF sites for tonight. The next shortwave
trough/associated low pressure over OK will be moving towards
central and southern IN by tomorrow morning. Expect another day of
MVFR/occasional IFR/LIFR on Monday due to RA/TSRA near the
frontal boundary and ahead of the approaching low. Overcast
conditions expected through Monday evening with skies showing
some clearing for early Tuesday.
&&
.IND Watches/Warnings/Advisories...
Flash Flood Watch from 11 PM EDT this evening through Monday
evening for INZ043>048-051>057-060>065-067>072.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....JH
AVIATION...DWM
Area Forecast Discussion
National Weather Service Northern Indiana
354 PM EDT SUN JUL 3 2016
.SYNOPSIS...
Issued at 141 PM EDT Sun Jul 3 2016
A slow moving warm front to our south will gradually work north
through Monday as a wave of low pressure rides along the front.
This will bring increasing chances for showers and a few
thunderstorms to the region today through Independence day. The
greatest chance for rain will be near and south of the highway 24
corridor with lesser chances to the north. It will be mostly
cloudy across the entire area through Monday evening. High
temperatures will be in the upper 60s and 70s today, and the mid-
upper 70s Monday. Low temperatures tonight will be in the upper
50s and 60s.
&&
.SHORT TERM...(This Evening through Monday)
Issued at 353 PM EDT Sun Jul 3 2016
A stationary front was near the Ohio River with a large are of rain
north of the front across Illinois into Indiana and Ohio. Rain
cooled air north of the front had accentuated the thermal boundary
with afternoon temperatures only in low to mid 60s where rain and
storms were occurring from central Illinois to central Indiana.
Surface based CAPEs had risen above 3000 J/Kg per SPC meso analysis
south of the front near the Ohio River where storms should intensify
later this afternoon. The GFS was generating too much precipitation
in the northern portion of the area of rain. Thunderstorms were
limited to the far southern edge of the area of rain where the
airmass was move favorable for convection. Have removed thunder from
this afternoon and this evening. The best chance for thunder will be
when a weak wave tries to lift north along the surface boundary. It
looks like the chance for heavy rain is low, although precipitable
water values should exceed 2.0 inches over far south and southeast
areas including Marion and Lima. Widespread conviction near the Ohio
River will limit north transport of moisture.
&&
.LONG TERM...(Monday Night through Sunday)
Issued at 353 PM EDT Sun Jul 3 2016
The upper air flow should become west/southwest aloft later this
week and allow short wave energy to move across the area as a
longwave trof amplifies along the west CONUS. This pattern should
allow the front to lift north across the area allowing very warm and
humid conditions Wednesday through Friday. There is a good chance
for thunderstorms during this period as precipitable water values
approach or exceed 2.0 inches. Highs between 85 and 90 degrees will
render heat indices in the 90s Wednesday through Friday. Cooler and
less humid air will return this coming weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 141 PM EDT Sun Jul 3 2016
Lower confidence in the forecast this afternoon as moderate to
heavy precipitation struggles to lift northward into the region.
Higher resolution models suggest that conditions will remain dry
at both TAF terminals this afternoon and evening. Discrepancies
arrive late tonight into tomorrow with the potential for rain
showers, and as to how far the ceilings will drop tonight into
tomorrow. For now kept SBN dry through the period, and have VCSH
in for FWA tomorrow afternoon. Kept things MVFR for now, but
there is potential for IFR ceilings tonight and Monday-especially
at FWA with moisture advection bringing PWATS up to 2 inches.
&&
.IWX Watches/Warnings/Advisories...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MCD
SHORT TERM...Skipper
LONG TERM...Skipper
AVIATION...MCD
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Area Forecast Discussion
National Weather Service Indianapolis IN
300 PM EDT SUN JUL 3 2016
.UPDATE...
The SYNOPSIS, NEAR TERM, SHORT TERM, and LONG TERM sections have
been updated below.
&&
.SYNOPSIS...
Issued at 300 PM EDT Sun Jul 3 2016
A front and areas of low pressure will keep chances for rain, some
of it heavy, across central Indiana through Independence Day. After
a brief break Tuesday, rain chances return Wednesday into next
weekend for most of the area with very warm and humid air in place.
&&
.NEAR TERM.../Rest of This Afternoon and Tonight/
Issued at 300 PM EDT Sun Jul 3 2016
An upper level wave is producing widespread rain across much of
central and eastern Illinois into the northern half of central
Indiana at the moment. Some of the storms, across southern Illinois,
had heavy rain. The wave and its associated rain will continue to
push east across central Indiana for the remainder of the afternoon.
Will continue high PoPs through the afternoon over the area.
Focus then shifts to chances for rain overnight. An area of low
pressure will move east into the area along a warm front. The front
will move a little farther north into the area. There will be some
broad forcing with decent isentropic lift and the area will be close
to the right entrance region of an upper jet. In addition, there
will be some frontogenetic forcing as well.
Moisture will continue to be plentiful with precipitable water
values near 2 inches. Thus feel heavy rain is still a threat,
especially with frontogenetical forcing in play.
However, several models have shifted south once again with the heavy
rain axis. Some take this to an extreme. For example, the high-res
short term models hardly have any rain at all across the northern
forecast area after 00Z (with support from the 12Z GFS). While
cannot rule out a quick cutoff of rain somewhere across the forecast
area, am not ready to cut back PoPs north wholesale given the
expected forcing across the area.
Thus went likely PoPs north and categorical PoPs south tonight. Even
though went categorical, cut back the highest PoPs to the far south
where better confidence exists.
Given the above will keep Flash Flood Watch as is for now, although
feel the highest threat will be in the southern part of the area.
&&
.SHORT TERM.../Monday through Wednesday/
Issued at 300 PM EDT Sun Jul 3 2016
Focus remains on chances for rain through the period.
The front remains in the area along with another wave of low
pressure. Best forcing will remain closer to the front in the
southern and eastern forecast area. Will go likely or low
categorical PoPs there with only chance PoPs across the far
northwest. Moisture remains plentiful so the Flash Flood Watch still
looks good during the day Monday.
For Monday night, the system will be pulling off to the east, so
only went slight chance PoPs far northwest to chance PoPs elsewhere.
Gradually diminished PoPs through the night from northwest to
southeast as the system exits.
Brief ridging will build in on Tuesday keeping the area dry. An
upper wave will bring more chances for rain starting overnight
Tuesday night in the west and all areas on Wednesday. Went high
chance PoPs all areas by Wednesday afternoon given plenty of
instability and moisture to work with as the wave moves in.
Generally stayed with a blend of MOS and raw model output for
temperatures through the period.
&&
.LONG TERM /Wednesday Night through Sunday/...
Issued at 300 PM EDT Sun Jul 3 2016
Model Ensembles indicate a flat upper ridge over the deep south and
a series of upper disturbances riding along the top of the ridge
across our region from Wednesday night through Friday evening.
This will result in a good chance of thunderstorms across our
region.
A weak cold front will push south across Indiana Friday night and
stall across kentucky over the weekend as weak high pressure builds
into the great lakes. The 12Z EURO is mostly dry over the
weekend...while the GFS brings a couple of weak disturbances across
southern Indiana and Ohio valley. Kept a slight chance of
thunderstorms central and south over the weekend due to model
uncertainty...while the north will be mostly dry Saturday night on.
Model Blend indicate it will be humid with slightly above normal
temperatures through Friday and a little less humid with near normal
temperatures over the weekend.
&&
.AVIATION /Discussion for the 031800Z TAF Issuance/...
Issued at 120 PM EDT Sun Jul 3 2016
Widespread rain with ceilings and visibilities mostly IFR through
early Monday morning. There could be a lull in showers and a
few storms late this afternoon over southern and central sections
and will mention a period of MVFR conditions KIND and southward.
Scattered thunderstorms will be the rule especially central and south
from late afternoon on. Low pressure over the southern plains will
move to central Illinois by midday Monday. Model soundings indicate
a gradual improvement to MVFR by midday Monday as a warm front drifts
north across central indiana.
Winds will be east to southwest 6 to 8 knots through tonight becoming
south by midday Monday and southwest after that.
&&
.IND Watches/Warnings/Advisories...
Flash Flood Watch through Monday evening for INZ043>048-051>057-
060>065-067>072.JAS/
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....JH
AVIATION...JH
Area Forecast Discussion
National Weather Service Northern Indiana
159 PM EDT SUN JUL 3 2016
.SYNOPSIS...
Issued at 141 PM EDT Sun Jul 3 2016
A slow moving warm front to our south will gradually work north
through Monday as a wave of low pressure rides along the front.
This will bring increasing chances for showers and a few
thunderstorms to the region today through Independence day. The
greatest chance for rain will be near and south of the highway 24
corridor with lesser chances to the north. It will be mostly
cloudy across the entire area through Monday evening. High
temperatures will be in the upper 60s and 70s today, and the mid-
upper 70s Monday. Low temperatures tonight will be in the upper
50s and 60s.
&&
.SHORT TERM...(Today and Tonight)
Issued at 405 AM EDT Sun Jul 3 2016
Dilemma in the short term forecast is on pcpn chances today and
tonight and how far north pcpn shield will extend. Large scale zonal
flow extended across the country this morning with embedded short
waves and convectively enhanced meso vorts. Our area remains on the
southern fringe of stronger westerlies. Copious moisture from Gulf
of Mexico was pumping into central Conus with PWATS well over 2
inches and sfc dewpoints in the 70s. Radar mosaic showed widespread
convection from eastern Kansas through north central Missouri into
central Illinois where short waves were interacting with the
moisture feed.
Models were a bit too far north with northern edge of pcpn shield at
06z but not too far off with axis of heavier pcpn from Kansas to
Missouri. General consensus among 00z models and latest CAMs is to
take heaviest pcpn east today and especially tonight near and south
of the interstate 70 corridor. This is where best low level jet will
be focused near warm frontal boundary and greatest moisture flux.
Latest HRRR and RAP are in decent agreement bringing some lighter
pcpn into far south by mid morning into the afternoon so kept pops
in the likely category there but trended to dry in the far
north today.
As sfc wave moves along front tonight...some northward shift in
boundary could allow period of moderate rainfall to move into far
southeast counties late tonight into Monday morning. Generally
relied on consensus of models and WPC QPF for tonight. This brings
between a half and one inch of rain into our area from near Marion
to Kalida and south as warm front inches northward.
&&
.LONG TERM...(Monday through Saturday)
Issued at 405 AM EDT Sun Jul 3 2016
Warm front to likely move north into our southeast forecast area
Monday while sfc wave moves along boundary. This will likely keep
showers and a few thunderstorms going near the front. Confined
pops to likely category with uncertainty concerning northward
extent of front and pcpn. This wave to slowly exit the east Monday
evening but some showers may still linger into mid or late evening
over the far southeast near trailing boundary.
Drier air and weak ridge move in for Tuesday and Tuesday night but
this will be short lived as models indicating an active pattern for
the rest of week with numerous short waves riding the relatively
faster flow aloft just to our north. Several rounds of thunderstorms
look possible as these waves interact with an increasingly moist and
unstable atmosphere that builds through the week. Being on southern
periphery of the faster westerlies...we should see a dramatic
increase in low level moisture...heat and instability. Models
indicating sfc dewpoints climbing well into the 70s as
evapotranspiration from maturing corn canopy adds additional
moisture to the lower levels. Details impossible to nail down at
this time frame but signals in models suggest several MCS/s could
develop upstream and dive toward our area. Blanket mid chance pops
continue with refinement coming in later forecasts.
High temps to trend up into the middle and upper 80s by mid week.
Warmer temps possible but given amount of moisture and convective
cloud debris cannot justify going warmer at this time.
However...profiles still support warmer sfc temps if any breaks in
clouds develop for a few hours. Overnight lows to trend into the 70s
with very muggy conditions likely.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 141 PM EDT Sun Jul 3 2016
Lower confidence in the forecast this afternoon as moderate to
heavy precipitation struggles to lift northward into the region.
Higher resolution models suggest that conditions will remain dry
at both TAF terminals this afternoon and evening. Discrepancies
arrive late tonight into tomorrow with the potential for rain
showers, and as to how far the ceilings will drop tonight into
tomorrow. For now kept SBN dry through the period, and have VCSH
in for FWA tomorrow afternoon. Kept things MVFR for now, but
there is potential for IFR ceilings tonight and Monday-especially
at FWA with moisture advection bringing PWATS up to 2 inches.
&&
.IWX Watches/Warnings/Advisories...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MCD
SHORT TERM...Lashley
LONG TERM...Lashley
AVIATION...MCD
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AREA FORECAST DISCUSSION
National Weather Service Topeka KS
319 PM CDT SUN JUL 3 2016
.SHORT TERM...(This Evening through Monday)
Issued at 318 PM CDT SUN JUL 3 2016
Water vapor imagery showed the shortwave that tracked over the
region early this morning situated over central and eastern Missouri
by this afternoon. As a result, much of the outlook area has been
mostly dry today, with only some isolated to scattered light showers
across portions of east central Kansas as the warm front remains
stationary just south of the forecast area. Widespread stratus
blanketed the region today, and this insolation resulted in
temperatures fluctuating very little today with afternoon highs only
reaching into the mid/upper 60s to mid 70s from north to south.
Models show the surface high pressure currently centered near the
Great Lakes region sliding southward into the area overnight into
Monday morning. Models show the stratus deck remaining in place
overnight, so this cloud cover should keep low temperatures in the
low/mid 60s. The main concern for overnight is for this stratus deck
to lower further overnight as a result of the approaching surface
high and the abundance of moisture in the boundary layer. Several
short-range models are suggesting that the low ceilings that are
already in place will only lower further, resulting in reduced
visibilities and areas of fog developing from around midnight
through around sunrise Monday morning. As a result, have continued
with the mention of areas of fog for the entire outlook area
overnight. There is some uncertainty with just how low visibilities
will drop, but some guidance suggests that visibilities will be low
enough to warrant a Dense Fog Advisory. However, will allow future
shifts to further evaluate this potential.
While visibilities should improve some by mid morning, the low
stratus deck may persist through the morning hours and should
gradually scatter out some during the afternoon, especially across
central Kansas. As a result, temperatures may be slow to rise during
the morning, but should reach into the low/mid 80s east to mid/upper
80s west during the afternoon across the forecast area.
.LONG TERM...(Monday Night through Sunday)
Issued at 318 PM CDT SUN JUL 3 2016
Monday night through Wednesday, A minor shortwave trough embedded
within the subtropical branch of the the upper level jet will move
from southwest KS and the TX PNHDL, east across KS and northern OK
into southwest MO and northwest AR Tuesday night into Wednesday.
As a lee surface trough deepens through the day Tuesday, southerly
low-level winds will advect deeper moisture northward across the
CWA. Scattered thunderstorms will develop across west central KS
Tuesday afternoon, along the surface trough/dryline and move east
across the CWA Tuesday night. The western counties may see isolated
thunderstorms developing during the late afternoon hours of Tuesday
as weak ascent spreads east across north central and central KS
during peak heating. The thunderstorms that develop across west
central KS may be strong to severe, since MLCAPES will increase to
around 3,000 J/KG, though the 0-6KM effective shear will only be
around 25 KTS. Some of these strong or possibly severe thunderstorms
may move into west central KS during the early and mid evening hours
of Tuesday. The storms should weaken as they move east across
northeast and east central KS over night.
The showers and thunderstorms will move east of the area by 12Z WED.
Skies will clear from west to east across the CWA during the mid to
late morning hours of Wednesday. Expect mostly sunny skies during
the afternoon hours of Wednesday.
Both Tuesday and Wednesday afternoon will be hot with highs in the
mid to upper 90s. Maximum afternoon heat indices will range from 102
to 109 degrees. A heat advisory will most likely be needed for
central, northeast and east central KS both Tuesday and Wednesday
afternoon.
For Wednesday night through Sunday, there looks to be scattered
precipitation chances for the entire period. This is due to quasi
zonal flow over the CONUS with multiple shortwaves transversing over
the area through the end of the week and weekend. As for
temperatures, Thursday looks to be the hottest day with high
temperatures near the mid 90s. Dewpoints near the mid 70s are
forecast for very eastern Kansas making heat indicies around 105
degrees possible on this day. The rest of the period will see
high temperatures in the low 90s and lows in the lower 70s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 1227 PM CDT SUN JUL 3 2016
IFR conditions are expected to continue into the mid-afternoon
hours at all terminals. BL heating/mixing should allow CIGS to
briefly lift to MVFR later this afternoon. IFR CIGS and VSBY are
introduced at 07Z at terminals as plentiful BL moisture should
allow stratus to build down as fog. Short-term guidance is
beginning to hint at the possibility of even lower VSBY near dawn
tomorrow morning, but due to low confidence will defer to the next
outlook for re-evaluation. Fog is expected to lift by 15Z
tomorrow morning back to an IFR stratus deck through midday.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Hennecke
LONG TERM...Gargan/Heller
AVIATION...Baerg
[top]
Area Forecast Discussion
National Weather Service Goodland KS
215 PM MDT SUN JUL 3 2016
.SHORT TERM...(This evening through Monday)
Issued at 213 PM MDT Sun Jul 3 2016
Currently across the Tri-State area there is an upper level trough
beginning to move east out of the region. As the trough continues to
move east through the area clouds will begin to decrease.
Temperatures are in the 70s/80s across the region with variable
winds at less than 10 mph.
The latest model runs of the NAM and HRRR have chances for PoPs this
afternoon over the far southwestern portions (possibly into the
northwestern portions) of the region as a weak shortwave moves over
the CWA. CAPES will get to around 1500 J/kg but bulk shear is not
impressive. The remainder of the night is expected to be dry.
Around midnight MDT, fog is expected to form over areas along and
east of Hwy 83. The SREF and NAM models have the fog lasting until
around 13/14Z Monday morning.
A ridge will move over the CWA Monday in the wake of the exiting
trough. This will bring with it warmer temperatures in the 90s.
There are slight chances for precipitation in the far western
portion of the region in the late afternoon as an upper level
shortwave moves towards the region.
.LONG TERM...(Monday night through Sunday)
Issued at 213 PM MDT Sun Jul 3 2016
The extended period will be fairly active with precipitation chances
possible everyday. Starting Monday night, the ridge gets pushed to
the east fairly quickly with a trough starting to push in from the
west. Precipitation chances continue into the evening and overnight
hours over the western portions of the region due to the shortwave
moving into the area. The upper level shortwave is slow moving, so
Tuesday is looking to be impacted by the same one and PoPs are
possible primarily in the eastern portions of the region. As the day
continues another 700 mb shortwave moves into the western portions
of the region bringing slight chances for precipitation during the
evening hours. CAPEs reach the 1200-1500 J/kg range so some stronger
storms are possible. Moving into Wednesday, a large portion of the
region could see precipitation as yet another shortwave moves
through the region on the east side of the trough. Thursday, as of
current model runs, looks the most impressive for storm chances due
to there being a cold front dipping down into the CWA from the north
as the trough moves into the northern portion of the region. CAPEs
get up to 1300 J/kg in area and bulk shear is in the 50-60 kt range.
Once that trough passes us another ridge moves into the region and
stays over the CWA through Saturday before another trough begins to
push into the west. Friday and Saturday look similar, but Saturday
night looks more impressive with a boundary along the Kansas,
Colorado border and a shortwave moving over the area. Sunday is
expected to dry out, for the most part, as a ridge moves into the
region. Temperatures are expected to be in the 90s the entire period
with a small drop on Thursday and Friday as the trough impacts the
region.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1139 AM MDT Sun Jul 3 2016
For KGLD, MVFR conditions will occur 18Z to 19Z. Then clouds will
start to move east of the area as the low pressure moves east. For
the remainder of the TAF period VFR conditions will prevail. High
pressure will move into the region and bring with it clearing
skies.
For KMCK, MVFR conditions will occur 18Z to 21Z until clouds
start to decrease over the region as the low pressure begins to
move east. VFR conditions will prevail after that until 06Z.
Starting at 06Z until 09Z MVFR conditions will return (with 4SM
visibilities) as fog begins to move into the area. Visibilities
will steadily decrease through the night as fog becomes thicker,
bringing with it IFR conditions as visibilities drop below 3SM. At
15Z visibilities will increase to 4SM but IFR conditions will
continue for the remainder of the TAF period due to low ceilings.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...CLT
LONG TERM...CLT
AVIATION...CLT