Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/26/16
Area Forecast Discussion
National Weather Service Tucson AZ
858 PM MST SAT JUN 25 2016
.SYNOPSIS...We now have enough moisture for isolated to scattered
showers and thunderstorms this weekend. A more favorable flow
regime will then provide increased coverage of showers and
thunderstorms Monday through Friday.
&&
.DISCUSSION...Water vapor imagery shows a stark contrast between a
dry mid level regime to our west and a moist airmass to the east.
This line generally extends from Flagstaff to Phoenix to Organ Pipe
National Monument. IR satellite imagery shows extensive mostly mid
level debris clouds from earlier convection that covers most of my
forecast area, with the exception of the far western portions of
Pima county.
Earlier this afternoon, isolated showers and storms developed over
the Santa Catalina and Rincon mountains and eventually drifted off
the mountains into the foothills with some gusty outflows and
moderately heavy rainfall on the northeast portion of the Tucson
metro and into the foothills. Several automated gauges reported
amounts of 0.50 inches to around 0.80 inches.
Currently, the radar mosaic from around the region indicates some
light activity from remnants of earlier convection south of the
border over eastern Santa Cruz and southwestern Cochise county and
drifting west to northwest. Additional activity is occurring in
southwestern New Mexico and drifting west, but this activity should
continue to decrease through the remainder of the evening. Will keep
a mention of a slight chance of showers and possible thunderstorms
in the forecast overnight, mainly near the borders with Mexico and
New Mexico.
As of 03Z (8 PM MST), temperatures across the region ranged from the
lower 70s near the international border, to the lower 90s over
northern and central parts of the forecast area. The Tucson
International Airport reported a temp of 89 degs after reaching an
afternoon high of 100 degs. These readings seem to be on track with
the inherited low temperature forecast, but will make some minor
adjustments to the short term hourly temperature grids to reflect
recent trends.
See the previous discussion below for details beyond tonight.
&&
.AVIATION...VALID THRU 27/06Z.
Isolated to scattered -TSRA/-SHRA again Sunday afternoon. Cloud
decks ranging from 10k- 15k ft msl. Gusty outflows possible with any
storms that develop, otherwise surface wind will generally be less
than 10 kts into Sunday. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this weekend. Greater coverage of showers and
thunderstorms should then occur Monday through next Friday.
Otherwise, daytime minimum relative humidity values will generally
range from the mid teens to around 30 percent with fair to good
nighttime recovery. 20-foot winds this weekend as well as
Wednesday through Friday will be terrain driven at less than 15
mph. 20-foot winds Monday and Tuesday will generally be from the
east at 5-15 mph with gusts of 15-20 mph. The strongest speeds
Monday and Tuesday should prevail from shortly after sunrise into
the early afternoon hours.
&&
.PREV DISCUSSION...For Sunday, some secondary consolidation in the
broad scale mean ridge position should tamp down convection with
most favored locations being the central mountains and international
border areas. Starting the day with what should still be a
relatively weaker flow will make storms initially reluctant to push
away from the mountains Sunday afternoon. However the UofA WRF-GFS
is hinting at a couple of nice strong outflows pushing west and
northwest late Sunday afternoon and early Sunday evening, filling in
valley locations and probably generating dust north of Tucson.
After that, as high pressure strengthens north of the area, the
first half of the new week should see a better flow regime (albeit
still on the weak side) for reinforcing deep moisture and importing
one or two weaknesses in the flow. This should serve to anchor the
entire week for seasonal convection.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
DISCUSSION...Mollere
PREVIOUS DISCUSSION...Meyer/Rasmussen
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
[top]
Area Forecast Discussion
National Weather Service Phoenix AZ
850 PM MST SAT JUN 25 2016
.SYNOPSIS...
A very warm air mass will keep temperatures above normal through at
least the first half of next week. A gradual increase in moisture
will seep into portions of Arizona later this weekend and into next
week, leading to a threat for showers and thunderstorms. Rainfall
will initially be limited to the higher terrain, then finally move
towards lower deserts as we move into next week.
&&
.DISCUSSION...
A bit of an increase in convective activity today when compared to
yesterday, but still very quiet at most locations. The main moisture
plume, as seen on latest water vapor satellite imagery shifted a bit
to the west today, allowing an increase in thunderstorm activity
over the Tucson area, where areas on the northeast side of that city
saw there 1st significant rainfall of the season, with some
locations seeing up to 0.75 inch late this afternoon. A few storms
also developed over the Rim Country, then tried to push
southeastward into southern Gila county before dissipating. One cell
did develop over the higher terrain north of US 60 between Superior
and Globe earlier this evening, and likely did produce some brief
heavy rainfall and gusty winds before dissipating. At this hour, all
that is left from these storms is a weak outflow boundary that is
now moving into northern Pinal/eastern Maricopa counties. The only
likely impact from this outflow is will be to jsut produce a bit of
gusty winds, up to 25 mph, which will likely not be strong enough to
produce any significant blowing dust. Based on current trends and
latest HRRR high-res forecasts, have reduced POPS somewhat and
removed blowing dust from the grids for the remainder of this
evening. As far as the forecast for Sunday is concerned, based on
the latest NAM/GFS model output, is still looks like it will be very
similar to today, and no further updates are planned.
&&
.PREVIOUS DISCUSSION...
Tonight and Sunday...
Forecast for the next 7 days are going to be quite challenging with
regards to thunderstorm threats as low/mid level moisture make a
slow creep from southeast AZ this weekend, west into the remainder
of the state throughout next week.
However for tonight and Sunday, most of our forecast area will be
dry with the exception of possible isolated thunderstorms over the
mountains of southern Gila County this evening, and again Sunday
evening. One thing that concerns us though, the models are
forecasting a large mid level inverted trof to develop over
northwest Mexico by late afternoon. We cant see it in the vapor
imagery, however models insist that its resultant broad cyclonic
circulation will rotate the bulk of convective debris clouds from
southeast AZ, into central and southern AZ tonight and Sunday
morning. This will mark the beginning of the slow westward moisture
push. Unfortunately the Guaymas sounding in northwest Mexico along
the Gulf coast has been missing for months now, so we cant get a
close look at this evolving feature from measured data, and will
have to default to the models and with their predictions of midlevel
moisture advection through Sunday.
Monday through Saturday...
A more established monsoon, in terms of moisture, is expected over
the southern half of AZ. The monsoon moisture boundary from
southeast AZ is expected to move into the Phoenix area by Tuesday,
then toward the lower Colorado River Valley by late Wednesday. In
other words, most of our southwest and south-central AZ zones will
be in the monsoon soup by the middle of next week, with enough
potential energy for possible convective threats, although its
really the little upper level nuances/perturbations that govern any
larger outbreaks, and or colliding outflow boundaries which are
difficult to discern this far in advance.
Therefore, as far as convective threats are concerned for next week,
we found that a broad brush approach to forecasting a slight chance
of convective threats nearly everywhere was best. This approach
actually started on the mid shift last night and accepted.
Another reason for the convective uncertainties involve the upper
level nuances/perturbations. Models forecast one large 300/250 mb
upper level inverted trof to move into southwest AZ from the
northern Gulf of CA on Monday, with several follow-up smaller
disturbances for the remainder of the week. Since the upper flow is
very weak over northern Mexico, which inherently make the models
less predictive or less reliable, and there are very few Mexican
weather balloon soundings launched, we will take a wait and see
position this far in advance before we jump on any one particular
day next week that could be convectively significant. Again a broad
brush slight chance of tstm approach is good for now, but hey, the
monsoon will be here.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Winds to remain on the light side, mainly aob 10 kts through Sunday,
following typical diurnal trends, likely becoming easterly around
midnight tonight, and westerly on Sunday afternoon. Scattered to
broken mid-high cloud layers to linger into Sunday as a result of
debris clouds from distant thunderstorms. There is once again an
outside chance that outflows from distant thunderstorms could affect
the terminals on Sun Aft/Eve, but confidence is too low to include
it in the tafs at this time.
Southeast California/Southwest Arizona including KIPL and KBLH:
Skies will remain mostly clear over both TAF sites through Sunday.
Winds will remain out of the south at KBLH and out of the south to
southeast at KIPL, with speeds generally aob 10 kts accompanied by a
few afternoon gusts up to 15 to 20 kts.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday...
Temperatures will be on a "cooling" trend, with highs on Tuesday
around 108-115F dropping into the 102-110F range by Saturday.
As monsoon moisture levels increase over the region, isolated
thunderstorms are possible each afternoon/evening over much of the
desert southwest, with the highest chances over the higher terrain
of central and eastern Arizona. Accompanying any storm that develops
will be wetting rains, gusty erratic winds, and lightning. This
increase in moisture will support a rise in minimum humidities, with
values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Percha/Vasquez
AVIATION...Percha
FIRE WEATHER...Hernandez
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
404 AM CDT FRI JUN 24 2016
.SHORT TERM...(Today and Tonight)
Issued at 307 AM CDT FRI JUN 24 2016
Early this morning a broad mid-level ridge remained in place across
the central and southern U.S. with water vapor imagery showing an
embedded shortwave over western Kansas that was helping to support a
cluster of early morning storms across southwest and south central
Kansas. At the surface, a warm front was stretched across east
central Kansas with a few scattered showers and storms noted south
of this boundary across southeast Kansas and far southwest Missouri.
Models show this warm front slowly lifting northward across the CWA
today. As the shortwave over western Kansas advances into eastern
Kansas this morning with the warm front nearby, short-range models
show the potential for some scattered storms to develop across
central and east central Kansas this morning and lift northward into
north central and northeast Kansas through the day. Forcing looks to
be fairly weak with barely 20kts of 0-6km bulk shear through the
day. While 3000-4000 J/kg of MUCAPE may be present, the weak forcing
and weak shear should keep storms sub-severe today. Due to the
uncertainty in the coverage of thunderstorm development amongst the
short-range models, have only slight to chance PoPs in for today.
With the warm front lifting into extreme northeast Kansas by early
this evening, any lingering isolated to scattered storms should be
focused near the NE/KS border. As a result, have PoPs diminishing
from south to north this evening and expect that much of the CWA
should remain predominantly dry. Another embedded shortwave is
expected to develop overnight across northwest and north central
Kansas with some isentropic lift noted across north central Kansas.
While there may not be much moisture present yet over north central
Kansas overnight into Saturday morning, felt that with the
isentropic lift in place it was worth keeping some slight chance
PoPs over far north central Kansas.
Despite some scattered low/mid-level clouds today, expect the breezy
southerly winds to aid in warm-air advection enough to support
afternoon high temperatures in the low/mid 90s with heat indices in
the upper 90s to around 100 degrees. The persistent southerly winds
and scattered cloud cover should keep overnight low temperatures a
bit warmer with lows only dropping into the low/mid 70s.
.LONG TERM...(Saturday through Thursday)
Issued at 307 AM CDT FRI JUN 24 2016
On Saturday, a strong upper trough will move along the Canadian
border, and will be strong enough to push a cold front into the
forecast area. Saturday will be hot as the thermal axis
immediately in advance of the cold front builds from SW into NE
Kansas. Models are in strong agreement with the timing of the
front entering the area after peak heating, but there is also an
expectation for storms and clouds to develop along the front and
possibly cool temperatures just slightly by late day. Regardless,
expect highs in the upper 90s in central KS to the middle 90s in
eastern KS. Dewpoints will probably mix out a bit in this
environment as well so expect max heat indices in the 98-104
range.
Strong convergence along the front will likely lead to
thunderstorm development, and those storms are likely to continue
as the front pushes southeast into the area although it is
uncertain just how widespread the coverage will remain overnight.
Moderate instability is expected with weak and disorganized shear
profiles. For the most part, will probably be looking for non-
severe storms although in the expected hot environment, there is
always that chance for sporadic severe downbursts with the
strongest storms, and also some low end potential for organized
bowing segments to develop with attendant wind threat. For now
though, the severe risk appears marginal and is reflected as such
in the SPC outlook.
The cold front is likely to stall over southern parts of the area
on Sunday with a rather unstable airmass expected to linger
through Sunday evening. There are model suggestions of a weak
short wave trough moving along the front on Sunday which could
trigger another round of thunderstorm development...again in the
moderate CAPE/low shear environment. A very similar scenario seems
likely to play out for Monday. So, while the chances for
widespread thunderstorms are not outstanding each day, the low
level focus exists with some potential for upper support and have
kept precip chances in the area through the period.
The flow pattern becomes more northwesterly by Tuesday with cooler
air filtering into northeast KS and highs finally expected to drop
back into the 80s. A well-organized short wave trough is expected
to move across the area from NW to SE Wednesday into Thursday and
will provide the area with several chances for thunderstorms. Wind
shear will be much better with this system so will want to watch
the period for severe potential. Otherwise expect generally cooler
temperatures through the end of the week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1139 PM CDT THU JUN 23 2016
Will keep VFR forecast at this time but note thunderstorms may be
near terminals periodically Friday. Enough time for next issuance
to take a look but at this time confidence too low to add to
forecast.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Hennecke
LONG TERM...Barjenbruch
AVIATION...67
Area Forecast Discussion
National Weather Service Goodland KS
300 AM MDT FRI JUN 24 2016
.SHORT TERM...(Today and tonight)
Issued at 222 AM MDT Fri Jun 24 2016
As the upper ridge over the plains shifts east ahead of the upper
low moving east through Montana along the U.S./Canada border, a
short wave trough embedded in the upper flow moves off the central
Rockies and across the central high plains region during the
evening and overnight hours tonight. During this time a
prefrontal trough deepens along the front range ahead of a cold
front that is expected to move across the forecast area early
Saturday. Expect isolated to scattered thunderstorms to develop
over the higher terrain to the west and move over a more favorable
instability environment with more available moisture east of the
deepening surface trough this evening with a marginal risk of
severe thunderstorms.High temperatures today with southerly flow
ahead of the surface trough will be well into the 90s.
High temperatures on Saturday following the cold front will be in
the 80s to lower 90s. On Saturday there may be a few lingering
early morning showers and thunderstorms across eastern portions of
the forecast area. Isolated storms are expected to redevelop and
become scattered over the far eastern sections of the forecast
area by afternoon along and ahead of the cold front where there is
a more favorable shear profile and greater instability and
available moisture. There is still only a marginal risk of severe
thunderstorms across the southeast portion of the forecast area in
the vicinity of the front.
Expect highs to be back into the lower 90s on Sunday with weak
westerly flow aloft and high pressure at the surface in the wake
of the cold front. A few thunderstorms are being hinted at mainly
along the southern extent of the forecast area in closer proximity
to the stationary boundary, but have gone mostly dry across the
forecast area.
.LONG TERM...(Saturday through Thursday)
Issued at 222 AM MDT Fri Jun 24 2016
The extended period has a very dominate ridge sitting over the
western CONUS with a closed low over the far northeastern states.
There is also a closed low that is sitting over the North Pacific
that tries to push east, but the ridge is very strong and it doesn`t
make much of a dent until Friday. As for the CWA, there are chances
for precipitation everyday; with best chances on Monday and
Wednesday; but still favorable chances Tuesday and Thursday. MUCAPE
values get up to 2300 J/kg Monday with bulk shear around 30 kts.
Wednesday has MUCAPE values of around 3500 J/kg and bulk shear up to
50 kts. In addition, Tuesday and Wednesday show to have 700 mb
shortwaves that push over the region crating better lift. Overall,
precipitation chances are expected next week but exact timing and
intensity will become more clear as the days get closer.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1144 PM MDT Thu Jun 23 2016
VFR conditions should continue through the TAF period. Isolated
showers/thunderstorms may still be possible, however confidence
that this would impact KGLD has greatly diminished and trends on
radar have been towards current activity weakening before reaching
KMCK. Fog/stratus may be possible in eastern Colorado by 12z, but
confidence is low that this would reach KGLD and VFR conditions
were prevailed. Winds should increase during the afternoon Friday
before decreasing again around sunset.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...LOCKHART
LONG TERM...CLT
AVIATION...DR
Area Forecast Discussion
National Weather Service Dodge City KS
346 AM CDT FRI JUN 24 2016
.SHORT TERM...(Today and tonight)
Issued at 340 AM CDT Fri Jun 24 2016
Another MCV may be developing across the area early this morning,
however, it should be exiting the forecast area by sunrise. As the
leftover outflow boundary will be likely well off to the east of our
area and subsidence settles in across the area, a dry forecast is
in place for the rest of the day. The models once again develop
higher terrain surface based storms late in the day, that with
weak steering flow remain in eastern Colorado and as far east as
northwest Kansas by the late evening. The outflow may not modify
the highs as much today as the cloud cover seemed to on Thursday,
as it is more likely longer duration insolation should be seen
today.
.LONG TERM...(Saturday through Thursday)
Issued at 340 AM CDT Fri Jun 24 2016
The next chance for focused thunderstorm development appears in the
late Saturday timeframe, along a surface boundary that straddles
the forecast area. These storms would likely not have significant
shear or steering also and might be tied to the boundary unless they
can develop a cold pool. At the same time, a closed low is shown by
the models to be moving through the northern Plains, maintaining a
nearly zonal flow aloft across the central Plains. Beyond that,
mesoscale features become increasingly difficult to infer from the
larger pattern, however the upper ridge does begin to redevelop
into mid week, supporting the warmer temperatures in the 90s
we`ve seen so far.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 607 PM CDT Thu Jun 23 2016
VFR conditions will prevail this evening with the possibility of a
squall line moving through the area overnight. If this squall
line comes to fruition, periods of MVFR conditions will be
observed. Winds will generally be from the east southeast at less
than 10 knots.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 94 MMM 95 68 / 20 10 20 40
GCK 95 MMM 95 67 / 20 20 20 20
EHA 95 MMM 95 67 / 20 20 20 30
LBL 96 MMM 97 68 / 20 10 20 30
HYS 94 MMM 94 66 / 20 20 30 30
P28 95 MMM 97 73 / 20 0 10 20
&&
.DDC Watches/Warnings/Advisories...NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Hovorka_42
Area Forecast Discussion...Corrected
National Weather Service Wichita KS
345 AM CDT FRI JUN 24 2016
.SHORT TERM...(Today through Sunday Night)
Issued at 345 AM CDT Fri Jun 24 2016
Forecast Highlight:
Thunderstorms anticipated for nearly all areas for most areas thru
next Thu.
Today:
A stationary front has remained positioned along the KS/OK border
throughout the night. Along & north of the front, thunderstorms
havebeen ongoing, the majority of which are the remnants of a
weakening MCS moving slowly east over SW KS. However, a north/south
oriented cluster of thunderstorms is slowly expanding from Kay
County OK to Butler County very close to a weak low-level jet. With
a strong mid-upper ridge situated from the Srn Plains to Nebraska &
IA, mid-level flow has been weak. As such locally heavy rains have
occurred, most notably Kay County OK but rainfall rates are also
increasing in Sumner & Butler counties. As a lower-deck trof slowly
strengthens across Ern CO the sfc-850 mb moisture axis would shift
slowly east across Ern KS. As such thunderstorms should be confined
to primarily SE KS this afternoon.
Tonight:
As a broadening mid-level trof moves slowly east toward the TX/OK
Panhandles drier air would spread NE across most of the CWA early
this evening, keeping most areas rain-free. The exceptions would be
the nwrn-most counties (Russell, Barton & Lincoln) where a lead mid-
level short wave ejecting NE toward, then across, the CO/KS border
will induce thunderstorms to redevelop over these areas. As such a
few thunderstorms may reach the above-mentioned counties very early
Sat Morning.
Rest of the Weekend:
An upper-deck cyclone that early this morning is centered over WA
& OR will strengthen considerably as it surges east across the Nrn
Plains. This would kick a cold front SE that may reach Central KS
late Sat Night. The projected track of the upper cyclone would
likely cause the front to decelerate as it moves further southeast
toward the turnpike. Thunderstorms would therefore increase with
the greatest increase across Central KS Sat Night. Deep-layer shear
remains fairly weak which would keep the severe potential marginal
at best. With a very moist & unstable airmass entrenched across
the neighborhood locally severe thunderstorms cannot be ruled
out. At this time, the highest potential for severe thunderstorms
would be across Central KS Sat Night & Sun where closer to the srn
segment of the strong ewd-surging mid-upper wave.
.LONG TERM...(Monday through Thursday)
Issued at 345 AM CDT Fri Jun 24 2016
With the front, though weakening, stalled in an east/west manner
across KS interacting with a very moist airmass, thunderstorms would
be expected for much of the upcoming work-week. Inherited forecast
addresses this situaton and was therefore kept intact.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1150 PM CDT Thu Jun 23 2016
VFR conditions are expected across the area for most locations
overnight into Fri. SHRA/TSRA beginning to develop near KDDC at
this time just ahead of a line of convection coming east off the
high plains near KGCK. Low level moisture transport out of the OK
panhandle is feeding this renewed convective development, with this
convection expected to make its way east-southeast late tonight into
early Fri morning. Propagation vectors suggests that the strongest
convection will move more SE than E, which would suggest most of
this renewed convection will drift south of the KRSL, KSLN and KGBD
TAFS. Plan on keeping a VCTS for KHUT and KICT for the 08-12z time
frame, as extrapolation of the convection may lead it to clipping
South Central KS. Still uncertain on how strong the storms will be,
but if they make it to KICT and KHUT then some MVFR vsbys or cigs
may be possible.
After the morning convection, expect VFR conditions to return the
area for FRI afternoon as the frontal boundary begins to lift back
north as a warm front.
Ketcham
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 94 74 98 76 / 30 10 10 30
Hutchinson 95 74 99 74 / 30 10 10 40
Newton 93 73 97 75 / 30 10 10 30
ElDorado 93 73 95 75 / 30 10 10 30
Winfield-KWLD 94 74 96 77 / 30 10 10 20
Russell 95 74 99 70 / 20 20 40 60
Great Bend 96 74 99 70 / 20 20 30 60
Salina 95 75 100 73 / 20 10 20 50
McPherson 95 74 99 74 / 20 10 20 40
Coffeyville 92 72 94 75 / 30 10 10 10
Chanute 92 72 94 75 / 30 10 10 20
Iola 91 72 94 74 / 40 10 10 20
Parsons-KPPF 92 73 94 75 / 30 10 10 10
&&
.ICT Watches/Warnings/Advisories...
None.
&&
$$
SHORT TERM...EPS
LONG TERM...EPS
AVIATION...BDK
Area Forecast Discussion...Corrected
National Weather Service Wichita KS
345 AM CDT FRI JUN 24 2016
.SHORT TERM...(Today through Sunday Night)
Issued at 345 AM CDT Fri Jun 24 2016
Forecast Highlight:
Thunderstorms anticipated for nearly all areas for most areas thru
next Thu.
Today:
A stationary front has remained positioned along the KS/OK border
throughout the night. Along & north of the front, thunderstorms
havebeen ongoing, the majority of which are the remnants of a
weakening MCS moving slowly east over SW KS. However, a north/south
oriented cluster of thunderstorms is slowly expanding from Kay
County OK to Butler County very close to a weak low-level jet. With
a strong mid-upper ridge situated from the Srn Plains to Nebraska &
IA, mid-level flow has been weak. As such locally heavy rains have
occurred, most notably Kay County OK but rainfall rates are also
increasing in Sumner & Butler counties. As a lower-deck trof slowly
strengthens across Ern CO the sfc-850 mb moisture axis would shift
slowly east across Ern KS. As such thunderstorms should be confined
to primarily SE KS this afternoon.
Tonight:
As a broadening mid-level trof moves slowly east toward the TX/OK
Panhandles drier air would spread NE across most of the CWA early
this evening, keeping most areas rain-free. The exceptions would be
the nwrn-most counties (Russell, Barton & Lincoln) where a lead mid-
level short wave ejecting NE toward, then across, the CO/KS border
will induce thunderstorms to redevelop over these areas. As such a
few thunderstorms may reach the above-mentioned counties very early
Sat Morning.
Rest of the Weekend:
An upper-deck cyclone that early this morning is centered over WA
& OR will strengthen considerably as it surges east across the Nrn
Plains. This would kick a cold front SE that may reach Central KS
late Sat Night. The projected track of the upper cyclone would
likely cause the front to decelerate as it moves further southeast
toward the turnpike. Thunderstorms would therefore increase with
the greatest increase across Central KS Sat Night. Deep-layer shear
remains fairly weak which would keep the severe potential marginal
at best. With a very moist & unstable airmass entrenched across
the neighborhood locally severe thunderstorms cannot be ruled
out. At this time, the highest potential for severe thunderstorms
would be across Central KS Sat Night & Sun where closer to the srn
segment of the strong ewd-surging mid-upper wave.
.LONG TERM...(Monday through Thursday)
Issued at 345 AM CDT Fri Jun 24 2016
With the front, though weakening, stalled in an east/west manner
across KS interacting with a very moist airmass, thunderstorms would
be expected for much of the upcoming work-week. Inherited forecast
addresses this situaton and was therefore kept intact.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1150 PM CDT Thu Jun 23 2016
VFR conditions are expected across the area for most locations
overnight into Fri. SHRA/TSRA beginning to develop near KDDC at
this time just ahead of a line of convection coming east off the
high plains near KGCK. Low level moisture transport out of the OK
panhandle is feeding this renewed convective development, with this
convection expected to make its way east-southeast late tonight into
early Fri morning. Propagation vectors suggests that the strongest
convection will move more SE than E, which would suggest most of
this renewed convection will drift south of the KRSL, KSLN and KGBD
TAFS. Plan on keeping a VCTS for KHUT and KICT for the 08-12z time
frame, as extrapolation of the convection may lead it to clipping
South Central KS. Still uncertain on how strong the storms will be,
but if they make it to KICT and KHUT then some MVFR vsbys or cigs
may be possible.
After the morning convection, expect VFR conditions to return the
area for FRI afternoon as the frontal boundary begins to lift back
north as a warm front.
Ketcham
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 94 74 98 76 / 30 10 10 30
Hutchinson 95 74 99 74 / 30 10 10 40
Newton 93 73 97 75 / 30 10 10 30
ElDorado 93 73 95 75 / 30 10 10 30
Winfield-KWLD 94 74 96 77 / 30 10 10 20
Russell 95 74 99 70 / 20 20 40 60
Great Bend 96 74 99 70 / 20 20 30 60
Salina 95 75 100 73 / 20 10 20 50
McPherson 95 74 99 74 / 20 10 20 40
Coffeyville 92 72 94 75 / 30 10 10 10
Chanute 92 72 94 75 / 30 10 10 20
Iola 91 72 94 74 / 40 10 10 20
Parsons-KPPF 92 73 94 75 / 30 10 10 10
&&
.ICT Watches/Warnings/Advisories...
None.
&&
$$
SHORT TERM...EPS
LONG TERM...EPS
AVIATION...BDK
Area Forecast Discussion
National Weather Service Wichita KS
328 AM CDT FRI JUN 24 2016
.SHORT TERM...(Today through Sunday Night)
Issued at 328 AM CDT Fri Jun 24 2016
Forecast Highlight:
Thunderstorms anticipated for nearly all areas for most areas thru
next Thu.
Today:
A stationary front has remained positioned along the KS/OK border
throughout the night. Along & north of the front, the majority of
which are the remnants of a weakening MCS moving slowly east over
SW KS. However, a north/south oriented cluster of thunderstorms is
slowly expanding from Kay County OK to Butler County very close to
a weak low-level jet. With a strong mid- upper ridge situated from
the Srn Plains to Nebraska & IA mid-level flow has been weak. As
such locally heavy rains have occurred, most notably Kay County OK
but rainfall rates are also increasing in Sumner & Butler counties.
As a lower-deck trof slowly strengthens across Ern CO the sfc-850
mb moisture axis would shift slowly east across Ern KS. As such
the rain should be confined to SE KS this afternoon.
Tonight:
As a broadening mid-level trof moves slowly east toward the TX/OK
Panhandles drier air would spread NE across most of the CWA early
this evening, keeping most areas rain-free. The exceptions would
be the nwrn-most counties, Russell, Barton & Lincoln) where a lead
mid-level short wave ejecting NE toward, then across, the CO/KS
border will induce thunderstorms to redevelop over these areas. As
such a few thunderstorms may reach the above-mentioned counties
very early Sat Morning.
Rest of the Weekend:
An upper-deck cyclone that early this morning is centered over WA
& OR will strengthen considerably as it surges east across the Nrn
Plains. This would kick a cold front SE that may reach Central KS
late Sat Night. The projected track of the upper cyclone would
likely cause the front to decelerate as it moves further southeast
toward the turnpike. Thunderstorms would therefore increase with
the greatest increase across Central KS Sat Night. Deep-layer shear
remains fairly weak which would keep the severe potential marginal
at best. With a very moist & unstable airmass entrenched across
the neighborhood locally severe thunderstorms cannot be ruled
out. At this time, the highest potential for severe thunderstorms
would be across Central KS Sat Night & Sun where closer to the srn
segment of the strong ewd-surging mid-upper wave.
.LONG TERM...(Monday through Thursday)
Issued at 328 AM CDT Fri Jun 24 2016
With the front, though weakening, stalled in an east/west manner
across KS interacting with a very moist airmass thunderstorms
would be expected for much of the upcoming work-week. Inherited
forecast was kept intact.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1150 PM CDT Thu Jun 23 2016
VFR conditions are expected across the area for most locations
overnight into Fri. SHRA/TSRA beginning to develop near KDDC at
this time just ahead of a line of convection coming east off the
high plains near KGCK. Low level moisture transport out of the OK
panhandle is feeding this renewed convective development, with this
convection expected to make its way east-southeast late tonight into
early Fri morning. Propagation vectors suggests that the strongest
convection will move more SE than E, which would suggest most of
this renewed convection will drift south of the KRSL, KSLN and KGBD
TAFS. Plan on keeping a VCTS for KHUT and KICT for the 08-12z time
frame, as extrapolation of the convection may lead it to clipping
South Central KS. Still uncertain on how strong the storms will be,
but if they make it to KICT and KHUT then some MVFR vsbys or cigs
may be possible.
After the morning convection, expect VFR conditions to return the
area for FRI afternoon as the frontal boundary begins to lift back
north as a warm front.
Ketcham
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 94 74 98 76 / 30 10 10 30
Hutchinson 95 74 99 74 / 30 10 10 40
Newton 93 73 97 75 / 30 10 10 30
ElDorado 93 73 95 75 / 30 10 10 30
Winfield-KWLD 94 74 96 77 / 30 10 10 20
Russell 95 74 99 70 / 20 20 40 60
Great Bend 96 74 99 70 / 20 20 30 60
Salina 95 75 100 73 / 20 10 20 50
McPherson 95 74 99 74 / 20 10 20 40
Coffeyville 92 72 94 75 / 30 10 10 10
Chanute 92 72 94 75 / 30 10 10 20
Iola 91 72 94 74 / 40 10 10 20
Parsons-KPPF 92 73 94 75 / 30 10 10 10
&&
.ICT Watches/Warnings/Advisories...
None.
&&
$$
SHORT TERM...EPS
LONG TERM...EPS
AVIATION...BDK
Area Forecast Discussion
National Weather Service Goodland KS
1144 PM MDT THU JUN 23 2016
.SHORT TERM...(Today and tonight)
Issued at 249 AM MDT Thu Jun 23 2016
Ongoing early morning convective activity continues eastward
across southwest KS today along a frontal boundary that extends
eastward into western Missouri and is laid up along the front
range on the western side. Convective activity is expected to
reinitiates later today along the front range and frontal
boundary where moisture has pooled and the instability axis is
located. Scattered storms will move east across the region
overnight. The is currently a slight risk of severe storms over
east central Colorado extending into west central Kansas. The main
threat will be winds and large hail with some localized heavy
rainfall possibly producing some flash flooding during the evening
hours.
The stronger westerly flow aloft remains well north of the
forecast area, but several weaker short wave trough move east of
the Rockies and across the central high plains through the short
term period. These short waves are appearing as diurnally driven
convective feedback features in the models as each of them seem to
appear over the higher terrain late each afternoon and move east
over the plains states during the afternoon and overnight hours
as they weaken downstream. As a result, expect isolated to
scattered late afternoon and evening thunderstorms to move across
the forecast area again Friday and Saturday. Additionally a cold
front will move across the central high plains region during the
day on Saturday in advance of the upper low moving east of the
northern Rockies and across the northern high plains in the
vicinity of U.S./Canada border. This will provide a good focus for
afternoon storms on Saturday.
Temperatures are expected to be above normal with highs rising
well into the 90s again on Friday, and backing off somewhat into
the 80s and lower 90s again on Saturday with the passage of the
cold front.
.LONG TERM...(Friday night through Thursday)
Issued at 307 PM MDT Thu Jun 23 2016
Forecast issues will be chances of precipitation through the period
and high temperatures. Satellite showing an amplified flow across
the Pacific to along the west coast of North America. The flow
flattens out over the country with a broad ridge across the southern
portion and lesser ridging/nearly zonal flow over the northern
portion.
Models differ with details on shortwave troughs through the Friday
night through Sunday period. Models are suffering a lot from
convective feedback and am thinking that they are overdoing the
convection/qpf, especially from the end of Saturday night into
Sunday. In cases would like to have made some specific periods dry
but collaboration is keeping some kind of mention of thunderstorms
in the forecast through the entire period.
Friday night...Shortwave trough is near the western end of the later
at beginning of the period with surface convergence near or just
west. Problem is that 700 mb are plus 16 to 17. At this time will
confine a slight chance to the far west initially. Expect
thunderstorms to work their way east across the area as shortwave
moves across.
After midnight another shortwave trough moves at the same time the
front moves through. This looks to either redevelop precipitation or
keep it going through the rest of the night.
Saturday/Saturday night...There looks to be ongoing thunderstorms in
at the start of the morning. Question then becomes how much
thunderstorm activity will be around in afternoon and night. Right
rear quadrant of upper jet begins to affect the area in the
afternoon and continues into the evening hours. However, you would
think that the front and second shortwave should be pushing the
moisture and thunderstorms out of the area by mid to late afternoon.
At this time will keep something in the southeast half but am
thinking the models are overdoing the qpf.
Front will cool temperatures off about 5 to 10 degrees. Tended to
go toward the slightly cooler guidance.
Sunday...Was briefed that this period would be dry. However, a
number of minor waves, some convectively induced, look to
sporadically produce precipitation. Uncertainty and collaboration
have kept some kind of pops in here. My gut feeling this day will be
dry.
Sunday night through Thursday...Model disagreement starts at the
beginning of this period and gets worse with time. It involves the
system moving from south central into eastern Canada and the
resulting troughing over the eastern portion of the country. It also
involves how the models handle the troughiness along the west coast.
The handling or mishandling of these features affects the amplitude
and the position of the western ridge. This ridge moves west with
time and models typically have difficulty in retrogressing patterns.
Models last week also had trouble with a similar setup. No matter
which model you choose there looks to be numerous, hard time,
shortwave troughs moving through in this flow.
There looks to be waffling stationary boundary across the area
during this time and because of the differences aloft, they differ
on where they put this boundary. As a result the extended gave me
slight chance to chance pops. Give the pattern, the uncertainty, and
near impossibility of getting the details right at this time scale,
have no problem in keeping those pops with only cosmetic changes.
This period does have the potential to be active and wet. Also a
result of the uncertainty, left the temperatures alone as well.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1144 PM MDT Thu Jun 23 2016
VFR conditions should continue through the TAF period. Isolated
showers/thunderstorms may still be possible, however confidence
that this would impact KGLD has greatly diminished and trends on
radar have been towards current activity weakening before reaching
KMCK. Fog/stratus may be possible in eastern Colorado by 12z, but
confidence is low that this would reach KGLD and VFR conditions
were prevailed. Winds should increase during the afternoon Friday
before decreasing again around sunset.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...LOCKHART
LONG TERM...BULLER
AVIATION...DR
Area Forecast Discussion
National Weather Service Goodland KS
1144 PM MDT THU JUN 23 2016
.SHORT TERM...(Today and tonight)
Issued at 249 AM MDT Thu Jun 23 2016
Ongoing early morning convective activity continues eastward
across southwest KS today along a frontal boundary that extends
eastward into western Missouri and is laid up along the front
range on the western side. Convective activity is expected to
reinitiates later today along the front range and frontal
boundary where moisture has pooled and the instability axis is
located. Scattered storms will move east across the region
overnight. The is currently a slight risk of severe storms over
east central Colorado extending into west central Kansas. The main
threat will be winds and large hail with some localized heavy
rainfall possibly producing some flash flooding during the evening
hours.
The stronger westerly flow aloft remains well north of the
forecast area, but several weaker short wave trough move east of
the Rockies and across the central high plains through the short
term period. These short waves are appearing as diurnally driven
convective feedback features in the models as each of them seem to
appear over the higher terrain late each afternoon and move east
over the plains states during the afternoon and overnight hours
as they weaken downstream. As a result, expect isolated to
scattered late afternoon and evening thunderstorms to move across
the forecast area again Friday and Saturday. Additionally a cold
front will move across the central high plains region during the
day on Saturday in advance of the upper low moving east of the
northern Rockies and across the northern high plains in the
vicinity of U.S./Canada border. This will provide a good focus for
afternoon storms on Saturday.
Temperatures are expected to be above normal with highs rising
well into the 90s again on Friday, and backing off somewhat into
the 80s and lower 90s again on Saturday with the passage of the
cold front.
.LONG TERM...(Friday night through Thursday)
Issued at 307 PM MDT Thu Jun 23 2016
Forecast issues will be chances of precipitation through the period
and high temperatures. Satellite showing an amplified flow across
the Pacific to along the west coast of North America. The flow
flattens out over the country with a broad ridge across the southern
portion and lesser ridging/nearly zonal flow over the northern
portion.
Models differ with details on shortwave troughs through the Friday
night through Sunday period. Models are suffering a lot from
convective feedback and am thinking that they are overdoing the
convection/qpf, especially from the end of Saturday night into
Sunday. In cases would like to have made some specific periods dry
but collaboration is keeping some kind of mention of thunderstorms
in the forecast through the entire period.
Friday night...Shortwave trough is near the western end of the later
at beginning of the period with surface convergence near or just
west. Problem is that 700 mb are plus 16 to 17. At this time will
confine a slight chance to the far west initially. Expect
thunderstorms to work their way east across the area as shortwave
moves across.
After midnight another shortwave trough moves at the same time the
front moves through. This looks to either redevelop precipitation or
keep it going through the rest of the night.
Saturday/Saturday night...There looks to be ongoing thunderstorms in
at the start of the morning. Question then becomes how much
thunderstorm activity will be around in afternoon and night. Right
rear quadrant of upper jet begins to affect the area in the
afternoon and continues into the evening hours. However, you would
think that the front and second shortwave should be pushing the
moisture and thunderstorms out of the area by mid to late afternoon.
At this time will keep something in the southeast half but am
thinking the models are overdoing the qpf.
Front will cool temperatures off about 5 to 10 degrees. Tended to
go toward the slightly cooler guidance.
Sunday...Was briefed that this period would be dry. However, a
number of minor waves, some convectively induced, look to
sporadically produce precipitation. Uncertainty and collaboration
have kept some kind of pops in here. My gut feeling this day will be
dry.
Sunday night through Thursday...Model disagreement starts at the
beginning of this period and gets worse with time. It involves the
system moving from south central into eastern Canada and the
resulting troughing over the eastern portion of the country. It also
involves how the models handle the troughiness along the west coast.
The handling or mishandling of these features affects the amplitude
and the position of the western ridge. This ridge moves west with
time and models typically have difficulty in retrogressing patterns.
Models last week also had trouble with a similar setup. No matter
which model you choose there looks to be numerous, hard time,
shortwave troughs moving through in this flow.
There looks to be waffling stationary boundary across the area
during this time and because of the differences aloft, they differ
on where they put this boundary. As a result the extended gave me
slight chance to chance pops. Give the pattern, the uncertainty, and
near impossibility of getting the details right at this time scale,
have no problem in keeping those pops with only cosmetic changes.
This period does have the potential to be active and wet. Also a
result of the uncertainty, left the temperatures alone as well.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1144 PM MDT Thu Jun 23 2016
VFR conditions should continue through the TAF period. Isolated
showers/thunderstorms may still be possible, however confidence
that this would impact KGLD has greatly diminished and trends on
radar have been towards current activity weakening before reaching
KMCK. Fog/stratus may be possible in eastern Colorado by 12z, but
confidence is low that this would reach KGLD and VFR conditions
were prevailed. Winds should increase during the afternoon Friday
before decreasing again around sunset.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...LOCKHART
LONG TERM...BULLER
AVIATION...DR
Area Forecast Discussion
National Weather Service Wichita KS
1150 PM CDT THU JUN 23 2016
.UPDATE...
Issued at 916 PM CDT Thu Jun 23 2016
Afternoon complex of storms is continuing to move to the east, with
just some stratiform showers on the western edge still lingering
across SE KS. Atmosphere in its wake across most of the forecast
area, has stabilized. So expecting a lull in the convective chances
for the rest of the evening hours. Still some concern for elevated
convection to redevelop late tonight or storms currently over the
high plains to drop east-southeast into western areas of the
forecast area early Fri morning. Current hi-res solutions differ on
how things will evolve early Fri morning. But latest RAP suggests
low level moisture will increase from the OK panhandle into South
Central KS after midnight. This moisture will overrun the stationary
frontal boundary that remains draped across SRN KS. Highly
conditional on if this moisture transport will be enough for storms
to redevelop over South Central KS, or will it keep the high plains
convection going east. Lots of uncertainty with either chance, but
with the stationary front draped across the area will keep some low
pops into Fri morning, in case either scenario leads to convection.
Ketcham
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 307 PM CDT Thu Jun 23 2016
Tonight into Friday:
Residual frontal boundary, contaminated largely by outflow effects
from the ongoing mcv-induced storm complex over south-central
Kansas, extends eastward from southern Kansas into southern
Missouri. Highest thunderstorm probabilities into early this
evening, should exist underneath and just east of this eastward
tracking mcv, with renewed convective development along the
attendant outflow boundaries. Very strong instability, anomalously
high precipitable water, steep low-level lapse rates exist in a
west-east axis underneath the above features, with modest deep
layer shear. Therefore, some of the stronger storm cores within
multi-cell clusters will produce strong-severe wet downburst winds
and torrential rainfall. Isolated diurnally-tied, nickel-quarter
size hail is also a threat. There should be a brief lull this
evening northwest of the KS Turnpike, with temporarily stabilized
air behind the mcv storm complex. However, additional convection
emanating from the higher terrain to the west within the monsoonal
plume, should propagate eastward overnight into a weak southerly
low-level jet. Storm chances should therefore increase again late
tonight into the early morning hours in central and south-central
Kansas. This activity would still be capable of strong downburst
winds and torrential rainfall under the strongest cores or multi-
cell clusters.
Will maintain at least low chances of lingering convection in
eastern Kansas Friday (mainly through midday), otherwise, return
southerly flow and some sunshine will lead to a return to the heat
and humidity for much of the area.
It is possible that the heat advisory for extreme southeast KS near
the Oklahoma border may be cancelled early, depending on how far
east convective outlfow effects reach in the next few hours.
Saturday through Sunday:
A strong, somewhat compact upper trough will sweep eastward from the
Northern Intermountain region, across the Northern Plains and
Upper Mississippi Valley during this period. The associated cold
front will slide southward into the Kansas region late Saturday,
while weakening and stalling somehere across the state by Sunday,
most likely in the south, while retaining its identity a bit more
than the models suggest. Well-mixed breezy south-southwesterly
boundary layer winds will allow very warm to hot conditions
Saturday ahead of the front, with highs in the mid-upper 90s.
Depending on how much the boundary layer dewpoints can lower,
highs around 100 will be possible northwest of the Kansas
Turnpike. With the upper ridge flattened, the monsoonal moist
plume will stretch from the southern rockies eastward over Kansas
near the front. Therefore, chances for at least scattered
thunderstorms appear reasonable initially in Central Kansas late
Saturday, potentially spreading into southern Kansas by Sunday.
Although highs may trim back a few degrees Sunday with the front
and storms in the region, readings will likely remain slightly
above normal with rather humid air.
.LONG TERM...(Monday through Thursday)
Issued at 307 PM CDT Thu Jun 23 2016
The medium range models have been consistent in showing the upper
ridge retrograding to the western states early next week, with
longwave upper troughing over the eastern CONUS. This pattern
will result in increased northwesterly flow aloft over the Central
Plains. A lingering frontal zone across the Central Plains will
serve as a focus for periodic thunderstorm chances, with upslope
flow over the high plains and embedded upper disturbances in the
northwest flow aloft serving as triggers for storms as well. The
front is progged to meander slowly southward by Thursday, in part
due to the embedded disturbances traversing the northwest flow
aloft, and also from the outflow effects of storm complexes. As a
result, slightly warmer than normal temperatures early in the
week, are projected to fall back to slightly below normal by
Thursday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1150 PM CDT Thu Jun 23 2016
VFR conditions are expected across the area for most locations
overnight into Fri. SHRA/TSRA beginning to develop near KDDC at
this time just ahead of a line of convection coming east off the
high plains near KGCK. Low level moisture transport out of the OK
panhandle is feeding this renewed convective development, with this
convection expected to make its way east-southeast late tonight into
early Fri morning. Propagation vectors suggests that the strongest
convection will move more SE than E, which would suggest most of
this renewed convection will drift south of the KRSL, KSLN and KGBD
TAFS. Plan on keeping a VCTS for KHUT and KICT for the 08-12z time
frame, as extrapolation of the convection may lead it to clipping
South Central KS. Still uncertain on how strong the storms will be,
but if they make it to KICT and KHUT then some MVFR vsbys or cigs
may be possible.
After the morning convection, expect VFR conditions to return the
area for FRI afternoon as the frontal boundary begins to lift back
north as a warm front.
Ketcham
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 74 95 74 97 / 50 20 10 10
Hutchinson 70 95 74 97 / 50 20 10 10
Newton 71 94 74 96 / 50 30 10 10
ElDorado 73 94 74 95 / 50 30 10 10
Winfield-KWLD 74 95 74 96 / 40 20 10 10
Russell 70 96 74 97 / 50 20 20 40
Great Bend 70 96 74 97 / 50 20 20 30
Salina 71 96 75 97 / 40 30 10 20
McPherson 72 95 74 97 / 50 30 10 10
Coffeyville 72 93 73 94 / 80 20 10 10
Chanute 71 92 73 94 / 80 30 10 10
Iola 70 92 73 94 / 80 30 10 10
Parsons-KPPF 71 92 73 94 / 80 30 10 10
&&
.ICT Watches/Warnings/Advisories...
None.
&&
$$
UPDATE...Ketcham
SHORT TERM...JMC
LONG TERM...JMC
AVIATION...BDK
Area Forecast Discussion
National Weather Service Flagstaff AZ
303 AM MST SUN JUN 26 2016
.SYNOPSIS...Dry and hot weather will persist across far western
Arizona today. Mid level moisture will remain over central and
eastern Arizona through Monday, and bring widely scattered showers
and thunderstorms. Strong, gusty winds are possible near any
storms. Monsoonal moisture to increase and spread across northern
Arizona on Tuesday, with increasing daytime shower and
thunderstorm activity lasting through the week.
&&
.DISCUSSION...
Northern Arizona will be slowly transitioning to a monsoon
thunderstorm pattern over the next two days. Strong and gusty
outflow winds should be expected near any storms or virga. The
Flagstaff airport did have 2 periods of outflow wind gusts to 48
and 47 mph yesterday, an indication of outflow speeds possible
through Monday afternoon.
Satellite imagery this morning shows the monsoonal moisture plume
running from NW Mexico through Tucson then northeastward through
New Mexico. Satellite derived pw values are up to near 1.5 inches
around Tuscon this morning. Models remain consistent in showing
mid level easterly flow increasing across central and southern AZ
today and this will allow moisture to slowly increase across areas
along and south of I-40 through Monday. Areas along the Utah
broder to remain hot and nearly cloud free today as this area is
under the high pressure circulation center.
Starting Tuesday, models are in good agreement with moist
easterly flow through Wednesday morning becoming light southerly
through Wednesday. Monsoonal moisture to remain overhead through
the week and daytime precip chances were nudged upward a few
points along the Mogollon Rim. Max temps to cool to near normal
for dates starting Wednesday.
&&
.AVIATION...For the 12Z Package...Isolated to scattered showers and
thunderstorms will redevelop from KFLG-KRQE southeast after 18Z. The
greatest aviation concern is storm outflow winds in excess of 40
kts. Otherwise, expect VFR conditions. Smoke downwind of active
wildfires may impact local visibility. Aviation discussion not
updated for TAF amendments.
&&
.FIRE WEATHER...Monsoon moisture will slowly increase northward each
day. Expect deeper moisture with increasing coverage in showers and
thunderstorms starting on Monday. Storm motion today and Monday will
generally be from northeast to southwest. Expect erratic and gusty
winds near any showers and storms.
Tuesday through Thursday...An active wet Monsoon weather pattern is
forecast with good shower and thunderstorm coverage each day across
northern Arizona.
.&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...DL
AVIATION...MCS
FIRE WEATHER...MCS
For Northern Arizona weather information visit
weather.gov/flagstaff
[top]
Area Forecast Discussion
National Weather Service Phoenix AZ
255 AM MST SUN JUN 26 2016
.SYNOPSIS...
A very warm air mass will keep temperatures above normal through at
least the first half of the week. A gradual increase in moisture
will seep into portions of Arizona today and into the middle of the
week, leading to a threat for showers and thunderstorms. Rainfall
will initially be limited to the higher terrain, then finally move
towards lower deserts as we move through the week.
&&
.DISCUSSION...
The monsoon has officially been underway since the middle of June,
but for the most part convection has been minimal except for a few
mountain storms east of Phoenix - most of the activity lately has
been confined to the mountains of southeast Arizona. This will be
changing in the very near future, and signs continue to point
towards a gradual import of moisture westward and into the central
Arizona deserts setting the stage for genuine desert monsoon
thunderstorms. A look at recent plot, raob and satellite data showed
the presence of an inverted trof moving westward and across
southeast Arizona; at 2 am showers could be seen moving west across
portions of Pima County associated with this feature. Latest Tucson
sounding showed mid level flow now out of the southeast instead of
west to southwest as was the case earlier in the week. Latest model
guidance including mesoscale models such as the NMM6km indicate that
the inverted trof will push west around the periphery of a building
high pressure system, moving across far southern AZ and northwest
Mexico today and tonight and as this occurs we can expect a few
showers or thunderstorms over the lower central and southwest
deserts during the day today. Despite the high building to our
north, the increasing clouds and humidity will keep high temps over
south central AZ below the 110 mark today, but drier air over the
western deserts and into SE California will allow high temps today
to climb to around 112 degrees - just slightly below excessive heat
thresholds.
Monday through Saturday...
A more established monsoon, in terms of moisture, is expected over
the southern half of AZ. The monsoon moisture boundary from
southeast AZ is expected to move into the Phoenix area by Tuesday,
then toward the lower Colorado River Valley by late Wednesday. In
other words, most of our southwest and south-central AZ zones will
be in the monsoon soup by the middle of the week, with enough
potential energy for possible convective threats, although its
really the little upper level nuances/perturbations that govern any
larger outbreaks, and or colliding outflow boundaries which are
difficult to discern this far in advance.
Therefore, as far as convective threats are concerned for the week,
we continue to feel that a broad brush approach to forecasting a
slight chance of convective threats nearly everywhere is best.
Another reason for the convective uncertainties involve the upper
level nuances/perturbations. Models forecast one large 300/250 mb
upper level inverted trof to move into southwest AZ from the
northern Gulf of CA on Monday, with several follow-up smaller
disturbances for the remainder of the week. Since the upper flow is
very weak over northern Mexico, which inherently make the models
less predictive or less reliable, and there are very few Mexican
weather balloon soundings launched, we will take a wait and see
position this far in advance before we jump on any one particular
day next week that could be convectively significant. Again a broad
brush slight chance of tstm approach is good for now, but hey, the
monsoon will be here.
By about Wednesday, precipitable water values will likely exceed 1.5
inches over much of the lower deserts from the lower Colorado River
Valley eastward, and as the monsoon moisture corridor becomes better
established, in addition to increasing thunderstorm coverage, the
potential for heavy rainfall will become enhanced as well. Something
else to look forward to later in the week. Of course, as the
atmosphere becomes wetter/more humid, the high temperatures will
trend downward and will likely drop below seasonal normals over
portions of the central deserts by the middle or latter portion of
the week.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Winds to remain on the light side, mainly aob 10 kts through Sunday,
following typical diurnal trends, likely becoming easterly around
midnight tonight, and westerly on Sunday afternoon. Scattered to
broken mid-high cloud layers to linger into Sunday as a result of
debris clouds from distant thunderstorms. There is once again an
outside chance that outflows from distant thunderstorms could affect
the terminals on Sun Aft/Eve, but confidence is too low to include
it in the tafs at this time.
Southeast California/Southwest Arizona including KIPL and KBLH:
Skies will remain mostly clear over both TAF sites through Sunday.
Winds will remain out of the south at KBLH and out of the south to
southeast at KIPL, with speeds generally aob 10 kts accompanied by a
few afternoon gusts up to 15 to 20 kts.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday...
Temperatures will be on a "cooling" trend, with highs on Tuesday
around 108-115F dropping into the 102-110F range by Saturday.
As monsoon moisture levels increase over the region, isolated
thunderstorms are possible each afternoon/evening over much of the
desert southwest, with the highest chances over the higher terrain
of central and eastern Arizona. Accompanying any storm that develops
will be wetting rains, gusty erratic winds, and lightning. This
increase in moisture will support a rise in minimum humidities, with
values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...CB/Vasquez
AVIATION...Percha
FIRE WEATHER...Hernandez
[top]
Area Forecast Discussion
National Weather Service Tucson AZ
858 PM MST SAT JUN 25 2016
.SYNOPSIS...We now have enough moisture for isolated to scattered
showers and thunderstorms this weekend. A more favorable flow
regime will then provide increased coverage of showers and
thunderstorms Monday through Friday.
&&
.DISCUSSION...Water vapor imagery shows a stark contrast between a
dry mid level regime to our west and a moist airmass to the east.
This line generally extends from Flagstaff to Phoenix to Organ Pipe
National Monument. IR satellite imagery shows extensive mostly mid
level debris clouds from earlier convection that covers most of my
forecast area, with the exception of the far western portions of
Pima county.
Earlier this afternoon, isolated showers and storms developed over
the Santa Catalina and Rincon mountains and eventually drifted off
the mountains into the foothills with some gusty outflows and
moderately heavy rainfall on the northeast portion of the Tucson
metro and into the foothills. Several automated gauges reported
amounts of 0.50 inches to around 0.80 inches.
Currently, the radar mosaic from around the region indicates some
light activity from remnants of earlier convection south of the
border over eastern Santa Cruz and southwestern Cochise county and
drifting west to northwest. Additional activity is occurring in
southwestern New Mexico and drifting west, but this activity should
continue to decrease through the remainder of the evening. Will keep
a mention of a slight chance of showers and possible thunderstorms
in the forecast overnight, mainly near the borders with Mexico and
New Mexico.
As of 03Z (8 PM MST), temperatures across the region ranged from the
lower 70s near the international border, to the lower 90s over
northern and central parts of the forecast area. The Tucson
International Airport reported a temp of 89 degs after reaching an
afternoon high of 100 degs. These readings seem to be on track with
the inherited low temperature forecast, but will make some minor
adjustments to the short term hourly temperature grids to reflect
recent trends.
See the previous discussion below for details beyond tonight.
&&
.AVIATION...VALID THRU 27/06Z.
Isolated to scattered -TSRA/-SHRA again Sunday afternoon. Cloud
decks ranging from 10k- 15k ft msl. Gusty outflows possible with any
storms that develop, otherwise surface wind will generally be less
than 10 kts into Sunday. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this weekend. Greater coverage of showers and
thunderstorms should then occur Monday through next Friday.
Otherwise, daytime minimum relative humidity values will generally
range from the mid teens to around 30 percent with fair to good
nighttime recovery. 20-foot winds this weekend as well as
Wednesday through Friday will be terrain driven at less than 15
mph. 20-foot winds Monday and Tuesday will generally be from the
east at 5-15 mph with gusts of 15-20 mph. The strongest speeds
Monday and Tuesday should prevail from shortly after sunrise into
the early afternoon hours.
&&
.PREV DISCUSSION...For Sunday, some secondary consolidation in the
broad scale mean ridge position should tamp down convection with
most favored locations being the central mountains and international
border areas. Starting the day with what should still be a
relatively weaker flow will make storms initially reluctant to push
away from the mountains Sunday afternoon. However the UofA WRF-GFS
is hinting at a couple of nice strong outflows pushing west and
northwest late Sunday afternoon and early Sunday evening, filling in
valley locations and probably generating dust north of Tucson.
After that, as high pressure strengthens north of the area, the
first half of the new week should see a better flow regime (albeit
still on the weak side) for reinforcing deep moisture and importing
one or two weaknesses in the flow. This should serve to anchor the
entire week for seasonal convection.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
DISCUSSION...Mollere
PREVIOUS DISCUSSION...Meyer/Rasmussen
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Phoenix AZ
850 PM MST SAT JUN 25 2016
.SYNOPSIS...
A very warm air mass will keep temperatures above normal through at
least the first half of next week. A gradual increase in moisture
will seep into portions of Arizona later this weekend and into next
week, leading to a threat for showers and thunderstorms. Rainfall
will initially be limited to the higher terrain, then finally move
towards lower deserts as we move into next week.
&&
.DISCUSSION...
A bit of an increase in convective activity today when compared to
yesterday, but still very quiet at most locations. The main moisture
plume, as seen on latest water vapor satellite imagery shifted a bit
to the west today, allowing an increase in thunderstorm activity
over the Tucson area, where areas on the northeast side of that city
saw there 1st significant rainfall of the season, with some
locations seeing up to 0.75 inch late this afternoon. A few storms
also developed over the Rim Country, then tried to push
southeastward into southern Gila county before dissipating. One cell
did develop over the higher terrain north of US 60 between Superior
and Globe earlier this evening, and likely did produce some brief
heavy rainfall and gusty winds before dissipating. At this hour, all
that is left from these storms is a weak outflow boundary that is
now moving into northern Pinal/eastern Maricopa counties. The only
likely impact from this outflow is will be to jsut produce a bit of
gusty winds, up to 25 mph, which will likely not be strong enough to
produce any significant blowing dust. Based on current trends and
latest HRRR high-res forecasts, have reduced POPS somewhat and
removed blowing dust from the grids for the remainder of this
evening. As far as the forecast for Sunday is concerned, based on
the latest NAM/GFS model output, is still looks like it will be very
similar to today, and no further updates are planned.
&&
.PREVIOUS DISCUSSION...
Tonight and Sunday...
Forecast for the next 7 days are going to be quite challenging with
regards to thunderstorm threats as low/mid level moisture make a
slow creep from southeast AZ this weekend, west into the remainder
of the state throughout next week.
However for tonight and Sunday, most of our forecast area will be
dry with the exception of possible isolated thunderstorms over the
mountains of southern Gila County this evening, and again Sunday
evening. One thing that concerns us though, the models are
forecasting a large mid level inverted trof to develop over
northwest Mexico by late afternoon. We cant see it in the vapor
imagery, however models insist that its resultant broad cyclonic
circulation will rotate the bulk of convective debris clouds from
southeast AZ, into central and southern AZ tonight and Sunday
morning. This will mark the beginning of the slow westward moisture
push. Unfortunately the Guaymas sounding in northwest Mexico along
the Gulf coast has been missing for months now, so we cant get a
close look at this evolving feature from measured data, and will
have to default to the models and with their predictions of midlevel
moisture advection through Sunday.
Monday through Saturday...
A more established monsoon, in terms of moisture, is expected over
the southern half of AZ. The monsoon moisture boundary from
southeast AZ is expected to move into the Phoenix area by Tuesday,
then toward the lower Colorado River Valley by late Wednesday. In
other words, most of our southwest and south-central AZ zones will
be in the monsoon soup by the middle of next week, with enough
potential energy for possible convective threats, although its
really the little upper level nuances/perturbations that govern any
larger outbreaks, and or colliding outflow boundaries which are
difficult to discern this far in advance.
Therefore, as far as convective threats are concerned for next week,
we found that a broad brush approach to forecasting a slight chance
of convective threats nearly everywhere was best. This approach
actually started on the mid shift last night and accepted.
Another reason for the convective uncertainties involve the upper
level nuances/perturbations. Models forecast one large 300/250 mb
upper level inverted trof to move into southwest AZ from the
northern Gulf of CA on Monday, with several follow-up smaller
disturbances for the remainder of the week. Since the upper flow is
very weak over northern Mexico, which inherently make the models
less predictive or less reliable, and there are very few Mexican
weather balloon soundings launched, we will take a wait and see
position this far in advance before we jump on any one particular
day next week that could be convectively significant. Again a broad
brush slight chance of tstm approach is good for now, but hey, the
monsoon will be here.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Winds to remain on the light side, mainly aob 10 kts through Sunday,
following typical diurnal trends, likely becoming easterly around
midnight tonight, and westerly on Sunday afternoon. Scattered to
broken mid-high cloud layers to linger into Sunday as a result of
debris clouds from distant thunderstorms. There is once again an
outside chance that outflows from distant thunderstorms could affect
the terminals on Sun Aft/Eve, but confidence is too low to include
it in the tafs at this time.
Southeast California/Southwest Arizona including KIPL and KBLH:
Skies will remain mostly clear over both TAF sites through Sunday.
Winds will remain out of the south at KBLH and out of the south to
southeast at KIPL, with speeds generally aob 10 kts accompanied by a
few afternoon gusts up to 15 to 20 kts.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday...
Temperatures will be on a "cooling" trend, with highs on Tuesday
around 108-115F dropping into the 102-110F range by Saturday.
As monsoon moisture levels increase over the region, isolated
thunderstorms are possible each afternoon/evening over much of the
desert southwest, with the highest chances over the higher terrain
of central and eastern Arizona. Accompanying any storm that develops
will be wetting rains, gusty erratic winds, and lightning. This
increase in moisture will support a rise in minimum humidities, with
values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Percha/Vasquez
AVIATION...Percha
FIRE WEATHER...Hernandez
AREA FORECAST DISCUSSION
National Weather Service San Diego CA
917 PM PDT SAT JUN 25 2016
.SYNOPSIS...
Temperatures will increase during the fist half of the week as a
ridge of high pressure builds over the Four Corners. Warmest
conditions will be felt over the Inland Empire and deserts. A
shallow marine layer will limit heating along the immediate
coast. There is a very marginal chance for a light shower or isolated
thunderstorm over the higher terrain Monday afternoon. Conditions
will cool slightly later in the week as the ridge of high pressure
weakens.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
At 900 PM a 500 MB ridge was positioned just off the CA
coast, resulting in predominantly clear skies and light winds
over SoCal. The lone exception was the immediate coast, where
areas of marine layer low clouds were slowly reforming.
Light onshore surface pressure gradients and a strong marine
layer inversion, close to 23 degrees F on the 00z NKX sounding,
will promote the continued development of a low stratus deck over
the coast and western valleys overnight. Otherwise clear skies
will persist for inland areas through Sunday morning.
The 500 mb ridge currently off the CA coast will shift toward
the Four Corners and strengthen to around 597 DM Monday and
Tuesday. This will result in increasing temperatures inland, with
the warmest conditions being felt over the Inland Empire and
deserts. A Heat Advisory remains in effect for these areas Sunday
afternoon through Wednesday evening to account for the warmer
conditions.
Aside from the heat, a weak easterly wave is forecast to
propagate over Sonora Mexico late Sunday into Monday. This
easterly wave should reach our region Monday afternoon, brining
with it an increase in mid-level moisture. Mid-level clouds associated
with this moisture may limit the afternoon heating some on
Monday. There will also be a slight chance of a light shower or
an isolated thunderstorm over the higher elevations Monday
afternoon.
The 500 mb ridge over the Four Corners will weaken late in the
week, resulting in a slight cooling trend Wednesday into the
weekend. Drier southwest flow will replace the easterly flow
aloft, keeping the bulk of the monsoonal moisture to our east
over AZ.
&&
.AVIATION...
260400Z...Coast/Valleys...Stratus will be slower to spread along the
coast tonight, with most coastal airports having BKN-OVC ceilings
starting between 06Z and 09Z. Bases will be 1000-1400 feet MSL with
tops to 1600 ft MSL. Stratus could spread up to 20 mi inland. Local
vis below 3 mi will occur in the valleys 10Z-15Z. Clearing will
occur 15Z-18Z Sunday, with areas of BKN-OVC stratus possibly
continuing within 3 mi of the coast through 21Z Sunday. Patchy
stratus with lower cloud bases will occur Sunday night. Confidence
of forecast is moderate.
Mountains/Deserts...Clear skies with unrestricted vis will continue
through Sunday morning.
&&
.MARINE...
900 PM...No hazardous marine weather is expected through Thursday.
&&
.BEACHES...
900 PM...Nearshore buoys show 4-5 foot swell at 15 seconds, mostly
from 200 degrees, with a very slight decrease from today. The south
swell will gradually lower through Sunday. Although swell and surf
will lower some Sunday, strong longshore and rips currents will
continue to create hazardous swimming conditions through Sunday
afternoon. A High Surf Advisory continues for the Orange County
beaches through Sunday, and a Beach Hazard Statement is in effect for
San Diego County for above average surf and strong rip currents.
&&
.SKYWARN...
Skywarn activation will not be needed today.
&&
.SGX Watches/Warnings/Advisories...
CA...Heat Advisory from noon Sunday to 8 PM PDT Wednesday for Apple
and Lucerne Valleys-Coachella Valley-Riverside County
Mountains-San Bernardino County Mountains-San Bernardino
and Riverside County Valleys-The Inland Empire-San Diego
County Deserts-San Diego County Mountains-San Gorgonio Pass
Near Banning.
Beach Hazards Statement through Sunday evening for San Diego
County Coastal Areas.
High Surf Advisory until 8 PM PDT Sunday for Orange County
Coastal Areas.
PZ...None.
&&
$$
PUBLIC...Albright
AVIATION/MARINE/BEACHES...Maxwell
Area Forecast Discussion
National Weather Service San Francisco Bay Area
852 PM PDT SAT JUN 25 2016
.SYNOPSIS...High pressure will remain our dominant weather
feature through the middle of next week, producing very warm and
dry conditions inland. A shallow marine layer will persist near
the coast along with light onshore flow. This will maintain
seasonably cool weather in coastal areas. Cooling is expected in
all areas late next week as a weak upper trough develops near the
West Coast.
&&
.DISCUSSION...As of 8:50 PM PDT Saturday...Skies were sunny
across our entire region today as high pressure aloft strengthened
over California. Most locations were anywhere from 3-9 degrees
warmer today than yesterday. Inland valley locations warmed into
the 90s. Meanwhile, a shallow marine layer and light onshore flow
maintained seasonably cool conditions at the coast where highs
were mostly in the 60s and 70s. The synoptic pattern is not
forecast to change much over the next several days, so we can
expect weather conditions through the middle of next week to be
similar to what they were today.
For the past few days there has not been sufficient moisture in
the shallow marine layer to produce more than a few patches of
night and morning low clouds near the coast. Based on the latest
NAM and WRF model output, it is not likely we will see widespread
low clouds and fog anytime soon, and what does develop will remain
confined to areas close to the ocean.
The medium range models agree that the upper ridge will weaken
late in the week as a weak upper trough develops near the West
Coast. This should result in at least modest cooling in all areas
starting Thursday.
&&
.AVIATION...As of 4:30 PM PDT Saturday...Surface high pressure
over the Pacific Northwest is bringing a dry northerly flow to the
area. Patchy low cigs will form overnight along the coast and MRY
Bay otherwise clear VFR conditions expected.
Vicinity of KSFO...VFR. Westerly winds 20-25 kt through 04z.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...IFR cigs after midnight. Confidence is
not high due to the patchy nature of the clouds as it may stay
VFR all night at MRY or SNS.
&&
.MARINE...as of 10:35 AM PDT Saturday...Steep seas and locally
strong northwest winds will continue across a majority of the
coastal waters through early next week. A long period southerly
swell will affect the waters through Saturday resulting in
breaking waves at near shore reefs and sand bars.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tngt...SCA...Pt Reyes to Pigeon Pt 0-10 nm
SCA...Pigeon Pt to Pt Pinos 0-10 nm
SCA...Pt Arena to Pigeon Pt 10-60 nm
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm
SCA...Pt Arena to Pt Reyes 0-10 nm
SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm
SCA...SF Bay until 9 PM
&&
$$
PUBLIC FORECAST: Dykema
AVIATION: Larry
MARINE: Larry
Visit us at www.weather.gov/sanfrancisco
Follow us on Facebook and twitter at:
www.Facebook.com/nwsbayarea
www.twitter.com/nwsbayarea
Area Forecast Discussion
National Weather Service Phoenix AZ
850 PM MST SAT JUN 25 2016
.SYNOPSIS...
A very warm air mass will keep temperatures above normal through at
least the first half of next week. A gradual increase in moisture
will seep into portions of Arizona later this weekend and into next
week, leading to a threat for showers and thunderstorms. Rainfall
will initially be limited to the higher terrain, then finally move
towards lower deserts as we move into next week.
&&
.DISCUSSION...
A bit of an increase in convective activity today when compared to
yesterday, but still very quiet at most locations. The main moisture
plume, as seen on latest water vapor satellite imagery shifted a bit
to the west today, allowing an increase in thunderstorm activity
over the Tucson area, where areas on the northeast side of that city
saw there 1st significant rainfall of the season, with some
locations seeing up to 0.75 inch late this afternoon. A few storms
also developed over the Rim Country, then tried to push
southeastward into southern Gila county before dissipating. One cell
did develop over the higher terrain north of US 60 between Superior
and Globe earlier this evening, and likely did produce some brief
heavy rainfall and gusty winds before dissipating. At this hour, all
that is left from these storms is a weak outflow boundary that is
now moving into northern Pinal/eastern Maricopa counties. The only
likely impact from this outflow is will be to jsut produce a bit of
gusty winds, up to 25 mph, which will likely not be strong enough to
produce any significant blowing dust. Based on current trends and
latest HRRR high-res forecasts, have reduced POPS somewhat and
removed blowing dust from the grids for the remainder of this
evening. As far as the forecast for Sunday is concerned, based on
the latest NAM/GFS model output, is still looks like it will be very
similar to today, and no further updates are planned.
&&
.PREVIOUS DISCUSSION...
Tonight and Sunday...
Forecast for the next 7 days are going to be quite challenging with
regards to thunderstorm threats as low/mid level moisture make a
slow creep from southeast AZ this weekend, west into the remainder
of the state throughout next week.
However for tonight and Sunday, most of our forecast area will be
dry with the exception of possible isolated thunderstorms over the
mountains of southern Gila County this evening, and again Sunday
evening. One thing that concerns us though, the models are
forecasting a large mid level inverted trof to develop over
northwest Mexico by late afternoon. We cant see it in the vapor
imagery, however models insist that its resultant broad cyclonic
circulation will rotate the bulk of convective debris clouds from
southeast AZ, into central and southern AZ tonight and Sunday
morning. This will mark the beginning of the slow westward moisture
push. Unfortunately the Guaymas sounding in northwest Mexico along
the Gulf coast has been missing for months now, so we cant get a
close look at this evolving feature from measured data, and will
have to default to the models and with their predictions of midlevel
moisture advection through Sunday.
Monday through Saturday...
A more established monsoon, in terms of moisture, is expected over
the southern half of AZ. The monsoon moisture boundary from
southeast AZ is expected to move into the Phoenix area by Tuesday,
then toward the lower Colorado River Valley by late Wednesday. In
other words, most of our southwest and south-central AZ zones will
be in the monsoon soup by the middle of next week, with enough
potential energy for possible convective threats, although its
really the little upper level nuances/perturbations that govern any
larger outbreaks, and or colliding outflow boundaries which are
difficult to discern this far in advance.
Therefore, as far as convective threats are concerned for next week,
we found that a broad brush approach to forecasting a slight chance
of convective threats nearly everywhere was best. This approach
actually started on the mid shift last night and accepted.
Another reason for the convective uncertainties involve the upper
level nuances/perturbations. Models forecast one large 300/250 mb
upper level inverted trof to move into southwest AZ from the
northern Gulf of CA on Monday, with several follow-up smaller
disturbances for the remainder of the week. Since the upper flow is
very weak over northern Mexico, which inherently make the models
less predictive or less reliable, and there are very few Mexican
weather balloon soundings launched, we will take a wait and see
position this far in advance before we jump on any one particular
day next week that could be convectively significant. Again a broad
brush slight chance of tstm approach is good for now, but hey, the
monsoon will be here.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Winds to remain on the light side, mainly aob 10 kts through Sunday,
following typical diurnal trends, likely becoming easterly around
midnight tonight, and westerly on Sunday afternoon. Scattered to
broken mid-high cloud layers to linger into Sunday as a result of
debris clouds from distant thunderstorms. There is once again an
outside chance that outflows from distant thunderstorms could affect
the terminals on Sun Aft/Eve, but confidence is too low to include
it in the tafs at this time.
Southeast California/Southwest Arizona including KIPL and KBLH:
Skies will remain mostly clear over both TAF sites through Sunday.
Winds will remain out of the south at KBLH and out of the south to
southeast at KIPL, with speeds generally aob 10 kts accompanied by a
few afternoon gusts up to 15 to 20 kts.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday...
Temperatures will be on a "cooling" trend, with highs on Tuesday
around 108-115F dropping into the 102-110F range by Saturday.
As monsoon moisture levels increase over the region, isolated
thunderstorms are possible each afternoon/evening over much of the
desert southwest, with the highest chances over the higher terrain
of central and eastern Arizona. Accompanying any storm that develops
will be wetting rains, gusty erratic winds, and lightning. This
increase in moisture will support a rise in minimum humidities, with
values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Percha/Vasquez
AVIATION...Percha
FIRE WEATHER...Hernandez
Area Forecast Discussion
National Weather Service Phoenix AZ
815 AM SUN JUN 26 2016
.SYNOPSIS...
A very warm air mass will keep temperatures above normal through at
least the first half of the week. A gradual increase in moisture
will seep into portions of Arizona today and into the middle of the
week, leading to a threat for showers and thunderstorms. Rainfall
will initially be limited to the higher terrain, then finally move
towards lower deserts as we move through the week.
&&
.DISCUSSION...
Regional upper air data showed the monsoon moisture boundary (MMB)
in southeast AZ was deeper than yesterday, and had shifted slightly
west and northwest since yesterday morning. In other words, the MMB
was between Phoenix and Tucson, or the leading edge of the deepest
moisture normally associated with a monsoon airmass extended from
the White Mountains in far east central AZ, southwestward to between
Phoenix and Tucson, then over to Ajo.
And there was another twist in this mornings complicated upper level
300/250 mb flow pattern, something totally unexpected this morning.
Yesterday at this time the models were forecasting a growing
inverted trof over northwest Mexico southwest of Tucson. We didnt
see its circulation in the mostly reliable water vapor imagery (WVI)
yesterday , but this morning it was obviouse in the WVI. However the
surprise is, the models are moving this feature north into AZ 24
hours ahead of schedule. In fact, the southwest/northeast orientated
cloud band over southern AZ is the leading edge of the 300/250 mb
deformation zone, forecast to shift northwestward throughout the
day. Again this is a whole 24 hours ahead of schedule. Like we said
yesterday, forecasting upper level features in a typical light wind
pattern of a subtropical airmass can give us fits, even in the short
term.
OK what does it all mean for our forecast area. With light east
southeasterly winds developing in a deep boundary layer, monsooon
moisture will continue to spread slowly west and north today. The
upper level inverted trof will continue to move north into AZ and
provide weak upper level support to any convective activity, first
over the mountains then later onto the deserts. Perhaps the best
threat for the greater Phoenix area will be gusty former tstm
outflow winds and blowing dust than a direct tstm hit. Any desert
convective threats will likely favor the Casa Grande, Gila Bend, and
west toward eastern Yuma County areas. The mid shift made
adjustments to precip probability coverage on the lower deserts due
to the inverted trof, and accepted. Otherwise no short term updates
are expected.
.PREVIOUS DISCUSSION...452 AM MST...
The monsoon has officially been underway since the middle of June,
but for the most part convection has been minimal except for a few
mountain storms east of Phoenix - most of the activity lately has
been confined to the mountains of southeast Arizona. This will be
changing in the very near future, and signs continue to point
towards a gradual import of moisture westward and into the central
Arizona deserts setting the stage for genuine desert monsoon
thunderstorms. A look at recent plot, raob and satellite data showed
the presence of an inverted trof moving westward and across
southeast Arizona; at 2 am showers could be seen moving west across
portions of Pima County associated with this feature. Latest Tucson
sounding showed mid level flow now out of the southeast instead of
west to southwest as was the case earlier in the week. Latest model
guidance including mesoscale models such as the NMM6km indicate that
the inverted trof will push west around the periphery of a building
high pressure system, moving across far southern AZ and northwest
Mexico today and tonight and as this occurs we can expect a few
showers or thunderstorms over the lower central and southwest
deserts during the day today. Despite the high building to our
north, the increasing clouds and humidity will keep high temps over
south central AZ below the 110 mark today, but drier air over the
western deserts and into SE California will allow high temps today
to climb to around 112 degrees - just slightly below excessive heat
thresholds.
Monday through Saturday...
A more established monsoon, in terms of moisture, is expected over
the southern half of AZ. The monsoon moisture boundary from
southeast AZ is expected to move into the Phoenix area by Tuesday,
then toward the lower Colorado River Valley by late Wednesday. In
other words, most of our southwest and south-central AZ zones will
be in the monsoon soup by the middle of the week, with enough
potential energy for possible convective threats, although its
really the little upper level nuances/perturbations that govern any
larger outbreaks, and or colliding outflow boundaries which are
difficult to discern this far in advance.
Therefore, as far as convective threats are concerned for the week,
we continue to feel that a broad brush approach to forecasting a
slight chance of convective threats nearly everywhere is best.
Another reason for the convective uncertainties involve the upper
level nuances/perturbations. Models forecast one large 300/250 mb
upper level inverted trof to move into southwest AZ from the
northern Gulf of CA on Monday, with several follow-up smaller
disturbances for the remainder of the week. Since the upper flow is
very weak over northern Mexico, which inherently make the models
less predictive or less reliable, and there are very few Mexican
weather balloon soundings launched, we will take a wait and see
position this far in advance before we jump on any one particular
day next week that could be convectively significant. Again a broad
brush slight chance of tstm approach is good for now, but hey, the
monsoon will be here.
By about Wednesday, precipitable water values will likely exceed 1.5
inches over much of the lower deserts from the lower Colorado River
Valley eastward, and as the monsoon moisture corridor becomes better
established, in addition to increasing thunderstorm coverage, the
potential for heavy rainfall will become enhanced as well. Something
else to look forward to later in the week. Of course, as the
atmosphere becomes wetter/more humid, the high temperatures will
trend downward and will likely drop below seasonal normals over
portions of the central deserts by the middle or latter portion of
the week.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Mostly light winds following typical diurnal trends for the Phoenix
terminals through tonight. Scattered to broken mid-high clouds to
persist through much of the period. Isolated showers and
thunderstorms should mostly stay over higher terrain, but there is an
outside chance of a few making it into the lower deserts. Storm
outflows remain more likely from distant thunderstorms and could
affect the terminals this evening, but confidence is too low to
include it in the tafs.
Southeast California/Southwest Arizona including KIPL and KBLH:
Clear skies this morning will give way to few to sct mid clouds by
noon. May see a few virga showers across southwest Arizona, but
should not affect area terminals. Winds will remain out of the south
at KBLH and out of the south to southeast at KIPL, with speeds
generally aob 10 kts accompanied by a few afternoon gusts up to 15 to
20 kts.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday...
Temperatures will be on a "cooling" trend, with highs on Tuesday
around 108-115F dropping into the 102-110F range by Saturday.
As monsoon moisture levels increase over the region, isolated
thunderstorms are possible each afternoon/evening over much of the
desert southwest, with the highest chances over the higher terrain
of central and eastern Arizona. Accompanying any storm that develops
will be wetting rains, gusty erratic winds, and lightning. This
increase in moisture will support a rise in minimum humidities, with
values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Vasquez
AVIATION...Kuhlman
FIRE WEATHER...Hernandez
Area Forecast Discussion
National Weather Service Phoenix AZ
452 AM MST SUN JUN 26 2016
.UPDATE...Updated aviation discussion...
&&
.SYNOPSIS...
A very warm air mass will keep temperatures above normal through at
least the first half of the week. A gradual increase in moisture
will seep into portions of Arizona today and into the middle of the
week, leading to a threat for showers and thunderstorms. Rainfall
will initially be limited to the higher terrain, then finally move
towards lower deserts as we move through the week.
&&
.DISCUSSION...
The monsoon has officially been underway since the middle of June,
but for the most part convection has been minimal except for a few
mountain storms east of Phoenix - most of the activity lately has
been confined to the mountains of southeast Arizona. This will be
changing in the very near future, and signs continue to point
towards a gradual import of moisture westward and into the central
Arizona deserts setting the stage for genuine desert monsoon
thunderstorms. A look at recent plot, raob and satellite data showed
the presence of an inverted trof moving westward and across
southeast Arizona; at 2 am showers could be seen moving west across
portions of Pima County associated with this feature. Latest Tucson
sounding showed mid level flow now out of the southeast instead of
west to southwest as was the case earlier in the week. Latest model
guidance including mesoscale models such as the NMM6km indicate that
the inverted trof will push west around the periphery of a building
high pressure system, moving across far southern AZ and northwest
Mexico today and tonight and as this occurs we can expect a few
showers or thunderstorms over the lower central and southwest
deserts during the day today. Despite the high building to our
north, the increasing clouds and humidity will keep high temps over
south central AZ below the 110 mark today, but drier air over the
western deserts and into SE California will allow high temps today
to climb to around 112 degrees - just slightly below excessive heat
thresholds.
Monday through Saturday...
A more established monsoon, in terms of moisture, is expected over
the southern half of AZ. The monsoon moisture boundary from
southeast AZ is expected to move into the Phoenix area by Tuesday,
then toward the lower Colorado River Valley by late Wednesday. In
other words, most of our southwest and south-central AZ zones will
be in the monsoon soup by the middle of the week, with enough
potential energy for possible convective threats, although its
really the little upper level nuances/perturbations that govern any
larger outbreaks, and or colliding outflow boundaries which are
difficult to discern this far in advance.
Therefore, as far as convective threats are concerned for the week,
we continue to feel that a broad brush approach to forecasting a
slight chance of convective threats nearly everywhere is best.
Another reason for the convective uncertainties involve the upper
level nuances/perturbations. Models forecast one large 300/250 mb
upper level inverted trof to move into southwest AZ from the
northern Gulf of CA on Monday, with several follow-up smaller
disturbances for the remainder of the week. Since the upper flow is
very weak over northern Mexico, which inherently make the models
less predictive or less reliable, and there are very few Mexican
weather balloon soundings launched, we will take a wait and see
position this far in advance before we jump on any one particular
day next week that could be convectively significant. Again a broad
brush slight chance of tstm approach is good for now, but hey, the
monsoon will be here.
By about Wednesday, precipitable water values will likely exceed 1.5
inches over much of the lower deserts from the lower Colorado River
Valley eastward, and as the monsoon moisture corridor becomes better
established, in addition to increasing thunderstorm coverage, the
potential for heavy rainfall will become enhanced as well. Something
else to look forward to later in the week. Of course, as the
atmosphere becomes wetter/more humid, the high temperatures will
trend downward and will likely drop below seasonal normals over
portions of the central deserts by the middle or latter portion of
the week.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Mostly light winds following typical diurnal trends for the Phoenix
terminals through tonight. Scattered to broken mid-high clouds to
persist through much of the period. Isolated showers and
thunderstorms should mostly stay over higher terrain, but there is an
outside chance of a few making it into the lower deserts. Storm
outflows remain more likely from distant thunderstorms and could
affect the terminals this evening, but confidence is too low to
include it in the tafs.
Southeast California/Southwest Arizona including KIPL and KBLH:
Clear skies this morning will give way to few to sct mid clouds by
noon. May see a few virga showers across southwest Arizona, but
should not affect area terminals. Winds will remain out of the south
at KBLH and out of the south to southeast at KIPL, with speeds
generally aob 10 kts accompanied by a few afternoon gusts up to 15 to
20 kts.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday...
Temperatures will be on a "cooling" trend, with highs on Tuesday
around 108-115F dropping into the 102-110F range by Saturday.
As monsoon moisture levels increase over the region, isolated
thunderstorms are possible each afternoon/evening over much of the
desert southwest, with the highest chances over the higher terrain
of central and eastern Arizona. Accompanying any storm that develops
will be wetting rains, gusty erratic winds, and lightning. This
increase in moisture will support a rise in minimum humidities, with
values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...CB/Vasquez
AVIATION...Kuhlman
FIRE WEATHER...Hernandez
[top]
Area Forecast Discussion
National Weather Service Tucson AZ
405 AM MST SAT JUN 25 2016
.SYNOPSIS...We now have enough moisture for isolated to scattered
showers and thunderstorms this weekend. A more favorable flow
regime will then provide increased coverage of showers and
thunderstorms Monday through next Saturday.
&&
.DISCUSSION...IR satellite imagery and surface observations depicted
mostly cloudy to cloudy skies across southeast Arizona early this
morning. KEMX WSR-88D detected isolated to scattered showers
producing mainly sprinkles from southwestern Cochise County westward
into western Pima County.
The 25/06Z Univ of AZ WRF-NAM and several HRRR solutions suggest
that mostly cloudy skies to cloudy skies will continue thru at least
mid-morning, and sprinkles to perhaps just a few hundredths of an
inch of rain should also prevail mostly west-to-south of Tucson.
These high resolution models then depict clearing skies from south-
to-north late this morning. The clearing skies will set the stage
for isolated to scattered showers and thunderstorms to develop by
early this afternoon southwest-to-southeast of Tucson. These showers
and thunderstorms should then move northwestward during the late
afternoon/early evening hours.
Have noted that the 25/06Z U/A WRF-NAM depicts a marked downtrend in
intensity of precip echoes early this evening. Assuming this
scenario to be reality, the potential for significant blowing dust
in the favorable dust-prone I-10 corridor from Tucson to Phoenix
would be mitigated. For this forecast package, have opted to depict
patchy blowing dust late this afternoon and early evening from the
far northwest Tucson metro area northwestward into south central
Pinal County and the northern portion of the Tohono O`Odham Nation.
Have also maintained isolated showers/tstms late tonight mainly
east of Tucson. The hi-res models suggest a scenario late tonight
similar to that presently occurring across the area. In other words,
a fairly widespread convective debris cloud cover with patches of
sprinkles or light rain.
26/00Z GFS/ECMWF/CMC remained fairly similar regarding the synoptic
scale pattern regime over the southwestern states starting Monday
and continuing into early next weekend. Strong high pressure aloft
Monday is progged to become centered over southern Utah. The GFS/
ECMWF depict an inverted trough to move into southwestern AZ from
the northern Gulf of California Monday.
Quick glance at the U/A WRF-NAM suggests that showers/tstms Monday
afternoon would only be confined to the White Mountains and near the
international border adjacent Santa Cruz/southern Pima County. Thus,
there is the potential that Monday may be a "down day" perhaps due
to subsidence on the eastern periphery of the aforementioned
inverted trough. Forecast confidence in this particular detail is
somewhat low, however. Thus, for this forecast package, have
continued with scattered showers/tstms mainly from Tucson
eastward/southward.
Thereafter, not much daily variation in shower/tstm coverage is
anticipated Tuesday into next Saturday. The deterministic GFS/ECMWF/
CMC were similar with maintaining fairly ample moisture across this
forecast area. These solutions were similar with the continuation of
a light ely/sely mid-level flow regime thru about Wednesday. The mid-
level flow regime is then progged to become more wly/swly especially
from Tucson westward starting Thursday and continuing into next
Saturday. This subtle change may be sufficient for at least a slight
downward trend in shower/tstm coverage, especially across western
sections. Again, forecast confidence is fairly low at this time in
stating that a definitive downward precip trend anywhere in the area
is in the offing late this week.
High temps for the Tucson metro area and locales west-to-northwest
of Tucson will be near normal during much of this forecast period.
However, daytime temps for locales east-to-south of Tucson, such as
Safford, Douglas and Nogales will average a few degs below normal
this week.
&&
.AVIATION...VALID THRU 27/12Z.
Isolated -SHRA especially west-to-south of KTUS thru about 15Z-17Z
this morning, then isolated to scattered -TSRA/-SHRA this afternoon
and evening. The best chance of -TSRA/-SHRA will occur from KTUS
vicinity eastward/southward to the New Mexico/international borders.
The best timing for TSRA at the KTUS/KOLS/KDUG terminals is mostly
from 20Z this afternoon until 27/02Z this evening. Brief wind gusts
to near 40 kts and MVFR conditions due to reduced visibilities will
be possible with the stronger TSRA. Isolated -SHRA/-TSRA will be
possible area-wide late tonight into early Monday morning.
Otherwise, cloud decks generally ranging from 10k-15k ft msl, and
surface wind terrain driven mainly less than 12 kts. Aviation
discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this afternoon and evening. Greater coverage of
showers and thunderstorms should then occur Monday through next
Saturday. Otherwise, daytime minimum relative humidity values will
generally range from the mid teens to around 30 percent with fair to
good nighttime recovery. 20-foot winds into Monday as well as
Thursday through Saturday will be terrain driven at less than 15
mph. 20-foot winds Tuesday and Wednesday will generally be from the
east at 5-15 mph with gusts of 15-20 mph. The strongest speeds
Tuesday and Wednesday should prevail from shortly after sunrise into
the early afternoon hours.
&&
.PREV DISCUSSION...For Sunday, some secondary consolidation in the
broad scale mean ridge position should tamp down convection with
most favored locations being the central mountains and international
border areas. Starting the day with what should still be a
relatively weaker flow will make storms initially reluctant to push
away from the mountains Sunday afternoon. However the UofA WRF-GFS
is hinting at a couple of nice strong outflows pushing west and
northwest late Sunday afternoon and early Sunday evening, filling in
valley locations and probably generating dust north of Tucson.
After that, as high pressure strengthens north of the area, the
first half of the new week should see a better flow regime (albeit
still on the weak side) for reinforcing deep moisture and importing
one or two weaknesses in the flow. This should serve to anchor the
entire week for seasonal convection.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
Francis
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Tucson AZ
336 PM MST SUN JUN 26 2016
.SYNOPSIS...Plenty of moisture around this week with an increasing
chance of mainly afternoon and evening showers and thunders across
Southeast Arizona.
&&
DISCUSSION...Convection is finally firing over expected areas,
including areas southeast through southwest of Tucson as well as
the east central mountains (northern Graham and Greenlee
counties). We had a delays in initiation due to morning cloud
cover as well as a bit more convective inhibition to overcome as
per the KTWC morning sounding.
So the strong outflow from the southern Mogollon Rim is just now
pushing southwest into valley locations of Graham county, and it
doesn`t really look as strong as the increasing mid level easterly
flow suggested earlier. Development across southern areas is
increasing, but not anything to write home about either. We may
still have some mid level CAPE for an outflow to tap into later
this evening, so more debris to contend with early Monday morning.
Weak subsidence behind a minor mid level feature shifting north of
the area will probably limit thunderstorms to mainly mountain
areas Monday.
A deeper and stronger fetch around high pressure reconsolidating
to our east should push our thunderstorm coverage up as we
reinforce available moisture and draw in weak inflections around
the high.
&&
AVIATION...VALID THRU 28/00Z.
Isolated to scattered -TSRA/-SHRA. The best timing for TSRA is
mostly from 20Z this afternoon until 27/08Z this evening. Brief
wind gusts to near 40 kts and MVFR conditions due to reduced
visibilities will be possible with the stronger TSRA. Isolated
-SHRA/-TSRA will be possible area-wide late tonight into early
Monday afternoon. Otherwise, cloud decks generally ranging from
10k- 15k ft MSL, and surface wind terrain driven mainly less than
12 kts. Aviation discussion not updated for TAF amendments.
&&
FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this afternoon and evening. Greater coverage of
showers and thunderstorms should then occur Monday through next
Saturday. Otherwise, daytime minimum relative humidity values will
generally range from the mid teens to around 30 percent with fair
to good nighttime recovery. 20-foot winds into Monday as well as
Thursday through Saturday will be terrain driven at less than 15
mph. 20-foot winds Tuesday and Wednesday will generally be from
the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds
Tuesday and Wednesday should prevail from shortly after sunrise
into the early afternoon hours.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Meyer/Rasmussen
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Tucson AZ
336 PM MST SUN JUN 26 2016
.SYNOPSIS...Plenty of moisture around this week with an increasing
chance of mainly afternoon and evening showers and thunders across
Southeast Arizona.
&&
DISCUSSION...Convection is finally firing over expected areas,
including areas southeast through southwest of Tucson as well as
the east central mountains (northern Graham and Greenlee
counties). We had a delays in initiation due to morning cloud
cover as well as a bit more convective inhibition to overcome as
per the KTWC morning sounding.
So the strong outflow from the southern Mogollon Rim is just now
pushing southwest into valley locations of Graham county, and it
doesn`t really look as strong as the increasing mid level easterly
flow suggested earlier. Development across southern areas is
increasing, but not anything to write home about either. We may
still have some mid level CAPE for an outflow to tap into later
this evening, so more debris to contend with early Monday morning.
Weak subsidence behind a minor mid level feature shifting north of
the area will probably limit thunderstorms to mainly mountain
areas Monday.
A deeper and stronger fetch around high pressure reconsolidating
to our east should push our thunderstorm coverage up as we
reinforce available moisture and draw in weak inflections around
the high.
&&
AVIATION...VALID THRU 28/00Z.
Isolated to scattered -TSRA/-SHRA. The best timing for TSRA is
mostly from 20Z this afternoon until 27/08Z this evening. Brief
wind gusts to near 40 kts and MVFR conditions due to reduced
visibilities will be possible with the stronger TSRA. Isolated
-SHRA/-TSRA will be possible area-wide late tonight into early
Monday afternoon. Otherwise, cloud decks generally ranging from
10k- 15k ft MSL, and surface wind terrain driven mainly less than
12 kts. Aviation discussion not updated for TAF amendments.
&&
FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this afternoon and evening. Greater coverage of
showers and thunderstorms should then occur Monday through next
Saturday. Otherwise, daytime minimum relative humidity values will
generally range from the mid teens to around 30 percent with fair
to good nighttime recovery. 20-foot winds into Monday as well as
Thursday through Saturday will be terrain driven at less than 15
mph. 20-foot winds Tuesday and Wednesday will generally be from
the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds
Tuesday and Wednesday should prevail from shortly after sunrise
into the early afternoon hours.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Meyer/Rasmussen
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
[top]
Area Forecast Discussion
National Weather Service Phoenix AZ
240 PM SUN JUN 26 2016
.SYNOPSIS...
A very warm air mass will keep temperatures above normal through at
least the first half of the week. A increase in monsoon moisture is
also expected, and will provide a slight threat of afternoon and
evening showers and thunderstorms the remainder of week.
&&
.DISCUSSION...
Tonight...
The inverted trof so noticeable on vapor imagery just south of the
AZ border developed an west-east deformation/stretching zone replete
with considerable mid/high level cloudiness. Cloudiness was able to
retard the heating curve and defer any precip to virga or light
showers with the dense clouds. More is expected overnight. However
there are a few afternoon thunderstorms in the less cloudy areas of
the White Mountains, just west of Nogales along the Mexican border,
and in far southeast AZ at 2 pm mst.
Monday through Saturday
The forecast becomes very complicated this week with respect to
shower/thunderstorm potential, coverage, and intensity, mainly
across portions of southwest and south central AZ. In other words,
can we call it quasi-unsettled this week?
We know the monsoon moisture boundary arrived in southeast AZ the
past couple of days, and is forecast to spread west and north across
the remainder of southern and central AZ this week. And, normally
this time of year once the moistures in place it should be like
clock-work right, i.e., first afternoon mountain thunderstorms then
by evening drifting toward the desert edge, including developing on
convective outflows and/or outflow collisions. Not this week, there
is too much going on in the mid and upper atmosphere.
For example, the last vestiges of the northwest Mexico inverted trof
will move into the region Monday afternoon. More cyclonicity over
southern CA will develop a threat of thunderstorms over the Joshua
Tree National Park mountains, while difluent flow aloft in southwest
and south central AZ generates convective potential as well. But a
caveat, extensive mid/high clouds associated with the inverted trof
axis may cut down on afternoon heating and the convective potential
in the south central AZ Monday.
And for Tuesday and Tuesday night, while 300/250 mb flows become
southwesterly, a developing 500 mb easterly flow advects a weak mid
level disturbance from New Mexico into southeast and south Central
AZ late Tuesday afternoon and night. 500 mb disturbances usually
spark overnight convection under very moist conditions.
Therefore there is much uncertainty, and we can go on and on for
Wednesday through Saturday. Therefore the best approach is to call
is quasi-unsettled, or a broad brush approach to shower/thunderstorm
potential since 1) the monsoon moisture will be in place, and 2)
models will no doubt have trouble forecasting any minor
perturbations in this developing convoluted flow aloft.
&&
.AVIATION...
South-Central Arizona including KPHX, KIWA, and KSDL:
Showers moving in from the southeast have caused winds to shift to a
southeasterly direction this afternoon over Phoenix terminals. With
more activity in southeast AZ still propagating to the northwest,
anticipate that these southeasterly winds will stick around for
another hour or so before shifting temporarily back to the west
around 22Z. Speeds will remain around 10 kts, however cannot rule
out gusty erratic winds and blowing dust from distant south and east
AZ storms for the remainder of the day at Phoenix terminals.
However, low confidence in exact spatial and temporal coverage
precludes mention in 18Z TAF. Broken to overcast mid to high clouds
aoa 10kft will continue to advect into the region for the remainder
of the day before decreasing in coverage early tomorrow morning.
Southeast California/Southwest Arizona including KIPL and KBLH:
Skies will remain mostly clear with a few passing high clouds around
15-20 kft. Winds will remain out of the south at KBLH and out of the
southeast at KIPL, with speeds generally around 10-15 kts
accompanied by a few afternoon gusts up to 20 to 25 kts.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Wednesday through Sunday...
Temperatures will continue to "cool," with highs on Wednesday around
105-112F dropping into the 100-110F range by Sunday.
As monsoon moisture levels continue to increase over the region,
isolated thunderstorms are possible each afternoon/evening over much
of the desert southwest, with the highest chances over the higher
terrain of central and eastern Arizona. Accompanying any storm that
develops will be wetting rains, gusty erratic winds, and lightning.
This increase in moisture will support a rise in minimum humidities,
with values ranging in the 15-25 percent range each day with good
overnight recoveries. Outside of gusty storm winds, speeds will
range between 5 to 15 mph with a few afternoon upslope gusts up to
20 mph.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Vasquez
AVIATION...Hernandez
FIRE WEATHER...Hernandez
[top]
Area Forecast Discussion
National Weather Service Flagstaff AZ
940 AM MST SUN JUN 26 2016
.SYNOPSIS...Dry and hot weather will persist across far western
Arizona today. Mid level moisture will remain over central and
eastern Arizona through Monday, and bring widely scattered showers
and thunderstorms. Strong, gusty winds are possible near any
storms. Monsoonal moisture to increase and spread across northern
Arizona on Tuesday, with increasing daytime shower and
thunderstorm activity lasting through the week.
&&
.DISCUSSION...For today, the highest moisture and best chances
for showers and thunderstorms will be along and south of the White
Mountains and the eastern Mogollon Rim. Elsewhere, drier air and
more stable conditions will limit convective activity. Slight
chances for showers are forecast along the western Mogollon Rim,
including the city of Flagstaff. This seems reasonable as an
extensive cumulus field is expected to develop with heating. As
highlighted in the previous forecast discussion, today`s storms
will once again be high-based leading to the potential for strong
outflows from collapsing storms.
In terms of forecast updates, the current forecast appears to be
on track and no short term updates are anticipated at this time.
&&
.PREV DISCUSSION /303 AM MST/... Northern Arizona will be slowly
transitioning to a monsoon thunderstorm pattern over the next two
days. Strong and gusty outflow winds should be expected near any
storms or virga. The Flagstaff airport did have 2 periods of
outflow wind gusts to 48 and 47 mph yesterday, an indication of
outflow speeds possible through Monday afternoon.
Satellite imagery this morning shows the monsoonal moisture plume
running from NW Mexico through Tucson then northeastward through
New Mexico. Satellite derived pw values are up to near 1.5 inches
around Tuscon this morning. Models remain consistent in showing
mid level easterly flow increasing across central and southern AZ
today and this will allow moisture to slowly increase across areas
along and south of I-40 through Monday. Areas along the Utah
border to remain hot and nearly cloud free today as this area is
under the high pressure circulation center.
Starting Tuesday, models are in good agreement with moist easterly
flow through Wednesday morning becoming light southerly through
Wednesday. Monsoonal moisture to remain overhead through the week
and daytime precip chances were nudged upward a few points along
the Mogollon Rim. Max temps to cool to near normal for dates
starting Wednesday.
&&
.AVIATION...For the 18Z Package...Isolated to scattered showers and
thunderstorms with possible gusts to 40kts will redevelop from KFLG-
KRQE southeast this afternoon and evening until around 02z.
Otherwise, expect VFR conditions. Aviation discussion not updated
for TAF amendments.
&&
.FIRE WEATHER...Monsoon moisture will slowly increase northward each
day. Expect deeper moisture with increasing coverage in showers and
thunderstorms starting on Monday. Storm motion today and Monday will
generally be from northeast to southwest. Expect erratic and gusty
winds near any showers and storms.
Tuesday through Thursday...An active wet Monsoon weather pattern is
forecast with good shower and thunderstorm coverage each day across
northern Arizona.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...RR/DL
AVIATION...MAS
FIRE WEATHER...MCS
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Tucson AZ
940 AM MST SUN JUN 26 2016
.SYNOPSIS...We now have enough moisture for isolated to scattered
showers and thunderstorms this weekend. A more favorable flow
regime will then provide increased coverage of showers and
thunderstorms Monday through next Saturday.
&&
.DISCUSSION...Still plenty of debris cloud this morning with
embedded light showers. This is going to slow the heating a bit
with initial clearing underway in portions of Cochise and Santa
Cruz counties. The 12Z KTWC sounding still has plenty of moisture
at 1.4 inches precipitable water. The mid level easterly flow has
already increased substantially accompanied by an increase in
shear that should help to organize outflow activity this
afternoon. The direction favors strong outflow off the Mogollon
Rim through Graham county.
Latest HRRR trends push 2 strong outflows westward, including the
Rim shot and a second outflow from activity in Cochise county
pushing west and northwestward. The 12z UofA WRF-NAM paints a
similar scenario with the outflow from the Cochise county activity
pushing through the Tucson Metro area around mid to late
afternoon. Minor adjustments to increase activity in the east
central mountains and subsequent outflow westward, otherwise we
have solid forecast trends. Please see the previous discussion
below for additional details.
&&
.AVIATION...VALID THRU 27/18Z.
Isolated to scattered -TSRA/-SHRA. The best timing for TSRA at
the KTUS/KOLS/KDUG terminals is mostly from 20Z this afternoon
until 27/02Z this evening. Brief wind gusts to near 40 kts and
MVFR conditions due to reduced visibilities will be possible with
the stronger TSRA. Isolated -SHRA/-TSRA will be possible area-wide
late tonight into early Monday morning. Otherwise, cloud decks
generally ranging from 10k- 15k ft MSL, and surface wind terrain
driven mainly less than 12 kts. Aviation discussion not updated
for TAF amendments.
&&
.FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this afternoon and evening. Greater coverage of
showers and thunderstorms should then occur Monday through next
Saturday. Otherwise, daytime minimum relative humidity values will
generally range from the mid teens to around 30 percent with fair
to good nighttime recovery. 20-foot winds into Monday as well as
Thursday through Saturday will be terrain driven at less than 15
mph. 20-foot winds Tuesday and Wednesday will generally be from
the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds
Tuesday and Wednesday should prevail from shortly after sunrise
into the early afternoon hours.
&&
.PREV DISCUSSION...The hi-res models suggest a scenario late
tonight similar to that presently occurring across the area. In
other words, a fairly widespread convective debris cloud cover
with patches of sprinkles or light rain.
26/00Z GFS/ECMWF/CMC remained fairly similar regarding the synoptic
scale pattern regime over the southwestern states starting Monday
and continuing into early next weekend. Strong high pressure aloft
Monday is progged to become centered over southern Utah. The GFS/
ECMWF depict an inverted trough to move into southwestern AZ from
the northern Gulf of California Monday.
Quick glance at the U/A WRF-NAM suggests that showers/tstms Monday
afternoon would only be confined to the White Mountains and near the
international border adjacent Santa Cruz/southern Pima County. Thus,
there is the potential that Monday may be a "down day" perhaps due
to subsidence on the eastern periphery of the aforementioned
inverted trough. Forecast confidence in this particular detail is
somewhat low, however. Thus, for this forecast package, have
continued with scattered showers/tstms mainly from Tucson
eastward/southward.
Thereafter, not much daily variation in shower/tstm coverage is
anticipated Tuesday into next Saturday. The deterministic GFS/ECMWF/
CMC were similar with maintaining fairly ample moisture across this
forecast area. These solutions were similar with the continuation of
a light ely/sely mid-level flow regime thru about Wednesday. The mid-
level flow regime is then progged to become more wly/swly especially
from Tucson westward starting Thursday and continuing into next
Saturday. This subtle change may be sufficient for at least a slight
downward trend in shower/tstm coverage, especially across western
sections. Again, forecast confidence is fairly low at this time in
stating that a definitive downward precip trend anywhere in the area
is in the offing late this week.
High temps for the Tucson metro area and locales west-to-northwest
of Tucson will be near normal during much of this forecast period.
However, daytime temps for locales east-to-south of Tucson, such as
Safford, Douglas and Nogales will average a few degs below normal
this week.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Meyer/Francis
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
AREA FORECAST DISCUSSION
National Weather Service Northern Indiana
143 PM EDT SUN JUN 26 2016
.SYNOPSIS...
Issued at 525 AM EDT Sun Jun 26 2016
Chances for showers and thunderstorms will increase from west to
east today as an upper level system moves into the area. Isolated
wind gusts greater than 50 mph and heavy rain will be the main
threats with thunderstorms this afternoon and early this evening.
Highs today will be near 90 with heat indices rising to near 100
degrees this afternoon. A drier and eventually cooler weather
pattern will then settle in for much of next week.
&&
.SHORT TERM...(Today and Tonight)
Issued at 520 AM EDT Sun Jun 26 2016
Very warm and humid air will spread northeast into the forecast area
today. Have issued a heat advisory for most of northern Indiana
until 6 pm EDT given a very warm start with early morning
temperatures in the 70s and given very humid air just upstream. Some
clouds may hinder the warmup today, but the heat index over much of
northern Indiana should rise to around 100 degrees later today.
A large area of thunderstorms extended across Iowa into Wisconsin
early this morning ahead of an upper trof. These storms will move
east later today. Wind directions in the lower atmosphere should be
relatively unidirectional and wind speed under 30 knots. Mid level
lapse rates will be relatively stable, close to 6.0C/Km. CAPE values
should rise to between 1500 and 2000 J/Kg per latest BUFKIT high
resolution soundings. Given favorable diurnal timing, some storms
will likely become strong and produce wind gusts in excess of 50
mph. Precipitable water values should climb above 2.0 inches so
heavy rainfall may cause localized flooding.
&&
.LONG TERM...(Monday through Saturday)
Issued at 520 AM EDT Sun Jun 26 2016
An upper level trof is expected to amplify this upcoming week and
bring dry and relatively cool weather to the area during the middle
of the week. The cold front should move across the area late Monday.
Lakeshore hazards along the southeast shore of Lake Michigan are
likely Monday night into Tuesday as winds become northwest behind
the front. Cooler weather will return during the middle of the week
as the long wave trof becomes established over eastern North
America. Lows should dip well into the 50s Tuesday night. Highs
should be in the 70s to around 80 from Tuesday through the end of
the week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 142 PM EDT Sun Jun 26 2016
Vfr conds xpcd through the pd. Prefntl trough in assocn/w sw
trough swirling through wrn ON stretching fm wrn lwr MI swwd
through wrn IL cont ewd through the aftn. Stabilization in wake of
morning outflw throws some uncertainty into how things redvlp
this aftn alg prefntl trough. Hwvr enough of concensus projection
of fvrd placement exists to drop prior tempo tsra grouping at
KSBN. While environmental flw through base of mid lvl trough
remains weak...rapidly destabilizing outflw bubble w/swd extent and
somewhat enhanced sfc convergence xpcd invof KFWA lt this aftn.
RAP UH progs suggests a fairly stg line of convn likely to result
this evening acrs ern IN/wrn OH which may yield a brief pd of
+tsra w/potential mvfr conds resulting. Will cont to monitor.
&&
.IWX Watches/Warnings/Advisories...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...Skipper
SHORT TERM...Skipper
LONG TERM...Skipper
AVIATION...T
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Area Forecast Discussion
National Weather Service Indianapolis IN
1235 PM EDT SUN JUN 26 2016
.UPDATE...
The AVIATION Section has been updated below.
&&
.SYNOPSIS...
Issued at 400 AM EDT Sun Jun 26 2016
A frontal system will move through the area this afternoon and
tonight, bringing thunderstorms to portions of the area. An
isolated severe storm cannot be ruled out, but a widespread severe
threat is unlikely. Heat indices in the very humid airmass will
approach 100 degrees at times this afternoon. A secondary cold
front will bring relief from the heat Monday night into Tuesday as
high pressure builds into the area behind it. Dry conditions will
dominate much of the week, with low precipitation chances
returning as next weekend arrives.
&&
.NEAR TERM /Rest of Today/...
Issued at 955 AM EDT Sun Jun 26 2016
.update...Continue to slow down the arrival time storms with isolated storms
by early afternoon and the best chances being 6 PM an beyond based on current
trends and HRR. Tweaked Highs down a degree over the northwest half of our region
due to increasing clouds. Otherwise...the rest of the near term is on track and no
updates other than grids are needed at this time.
Previous near term discussion follows....
Thunderstorm chances will steadily increase through the day as the
cold front approaches. While ample instability will be present
owing to the very warm and humid airmass ahead of the front, shear
is meager at best. Suppose the significant instability could
produce a pulse severe storm here or there, but do not expect
anything more than that. Hydrologic issues may be the more
pressing concern as precipitation efficiency should be quite high
with deep warm cloud owing to a freezing level pushing 14kft,
pseudotropical with very deep saturation, and storm motions which
are likely to be somewhat slow contributing to the potential for
some heavy rainfall. Additionally, observed rainfall in the last
week or two has been roughly 150 to as much as 400 percent of
normal in some portions of central Indiana. Will hit the flood
threat in the HWO.
Consensus temperatures looked reasonable with minor upward tweaks
where storms are expected to arrive latest in the day, mainly
south and southeast. Maximum heat index values will likely
approach and may briefly exceed 100 degrees across portions of the
area this afternoon. Indices should remain below advisory criteria
but will be mentioned in the HWO as this will be one of the hotter
days of the year thus far.
&&
.SHORT TERM /Tonight through Tuesday Night/...
Issued at 400 AM EDT Sun Jun 26 2016
Storm threat will persist into the evening across much of the area
and the overnight for at least portions of central Indiana. Again,
while an isolated pulse severe storm cannot be ruled out, think
sporadic hydrologic issues will be the more likely threat to
require monitoring. As the front exits the area late tonight into
early Monday morning, will rapidly taper off precip chances with
only the far southern area carrying a slight chance into the first
few hours of the day on Monday. The remainder of the short term
looks dry, although will have to monitor secondary cold frontal
passage Monday night into Tuesday as dewpoints will still be in
the 60s ahead of it.
Consensus temperatures appeared632 reasonable with minor tweaks
throughout the period, mainly late in the period.
&&
.LONG TERM /Wednesday through Saturday/...
Issued at 241 AM EDT Sun Jun 26 2016
Models and ensembles in good agreement that Canadian high pressure
will allow for dry weather with slightly below normal temperatures
through Thursday. Then, an upper trough will pivot east across the
Great Lakes and push a back door cold front across central Indiana
early next weekend. Regional blend suggests there could be a few
showers and thunderstorms around over all or parts of the area
starting Thursday night and continuing through Saturday, when the
front will likely move through. Temperatures should bounce back to
near normal with highs in the lower to mid 80s by Thursday or
Friday. Look for lows in the 50s Wednesday night and the 60s the
rest of the long term.
&&
.AVIATION /Discussion for 261800Z TAF Issuance/...
Issued at 1235 PM EDT Sun Jun 26 2016
VFR conditions expected throughout the period with the exception
of restrictions within convection later this afternoon and
evening.
Skies remain mostly sunny early this afternoon with light
southwest winds doing little to deter the muggy airmass over the
region. Cold front remains northwest of central Indiana currently
with a remnant outflow boundary from overnight storms in the upper
Midwest noted on satellite and radar over the northern Wabash
Valley. This feature may serve as the initial catalyst to fire
convection as it drops further into the forecast area over the
next few hours. With little shear and forcing aloft present
however...expect storms remain isolated to widely scattered
through about 21Z. A continued VCTS mention will suffice at all
sites. Will highlight SW winds veering to westerly by early
evening...but likely to see variable wind direction for a period
of time once the outflow passes.
Hi-res guidance continues to develop a broken line of convection
with the front for late afternoon and evening. Confidence is
higher in greater threat for convective impacts at all terminals
during this period and despite some question as to how extensive
storm coverage will eventually become in the absence of greater
shear...feel a 4 hour tempo group for storms producing brief
restrictions is prudent at all sites.
Any lingering convection will move south of the terminals with the
front overnight. A brief period of mid to high level clouds will
give way to mainly clear skies on Monday as deep subsidence
spreads into the region on N/NW winds.
&&
.IND Watches/Warnings/Advisories...NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/MK/JH
SHORT TERM...NIELD
LONG TERM...MK
AVIATION...RYAN
Area Forecast Discussion
National Weather Service Indianapolis IN
1012 AM EDT SUN JUN 26 2016
.UPDATE...
The AVIATION section has been updated below.
&&
.SYNOPSIS...
Issued at 400 AM EDT Sun Jun 26 2016
A frontal system will move through the area this afternoon and
tonight, bringing thunderstorms to portions of the area. An
isolated severe storm cannot be ruled out, but a widespread severe
threat is unlikely. Heat indices in the very humid airmass will
approach 100 degrees at times this afternoon. A secondary cold
front will bring relief from the heat Monday night into Tuesday as
high pressure builds into the area behind it. Dry conditions will
dominate much of the week, with low precipitation chances
returning as next weekend arrives.
&&
.NEAR TERM /Rest of Today/...
Issued at 955 AM EDT Sun Jun 26 2016
.update...Continue to slow down the arrival time storms with isolated storms
by early afternoon and the best chances being 6 PM an beyond based on current
trends and HRR. Tweaked Highs down a degree over the northwest half of our region
due to increasing clouds. Otherwise...the rest of the near term is on track and no
updates other than grids are needed at this time.
Previous near term discussion follows....
Thunderstorm chances will steadily increase through the day as the
cold front approaches. While ample instability will be present
owing to the very warm and humid airmass ahead of the front, shear
is meager at best. Suppose the significant instability could
produce a pulse severe storm here or there, but do not expect
anything more than that. Hydrologic issues may be the more
pressing concern as precipitation efficiency should be quite high
with deep warm cloud owing to a freezing level pushing 14kft,
pseudotropical with very deep saturation, and storm motions which
are likely to be somewhat slow contributing to the potential for
some heavy rainfall. Additionally, observed rainfall in the last
week or two has been roughly 150 to as much as 400 percent of
normal in some portions of central Indiana. Will hit the flood
threat in the HWO.
Consensus temperatures looked reasonable with minor upward tweaks
where storms are expected to arrive latest in the day, mainly
south and southeast. Maximum heat index values will likely
approach and may briefly exceed 100 degrees across portions of the
area this afternoon. Indices should remain below advisory criteria
but will be mentioned in the HWO as this will be one of the hotter
days of the year thus far.
&&
.SHORT TERM /Tonight through Tuesday Night/...
Issued at 400 AM EDT Sun Jun 26 2016
Storm threat will persist into the evening across much of the area
and the overnight for at least portions of central Indiana. Again,
while an isolated pulse severe storm cannot be ruled out, think
sporadic hydrologic issues will be the more likely threat to
require monitoring. As the front exits the area late tonight into
early Monday morning, will rapidly taper off precip chances with
only the far southern area carrying a slight chance into the first
few hours of the day on Monday. The remainder of the short term
looks dry, although will have to monitor secondary cold frontal
passage Monday night into Tuesday as dewpoints will still be in
the 60s ahead of it.
Consensus temperatures appeared632 reasonable with minor tweaks
throughout the period, mainly late in the period.
&&
.LONG TERM /Wednesday through Saturday/...
Issued at 241 AM EDT Sun Jun 26 2016
Models and ensembles in good agreement that Canadian high pressure
will allow for dry weather with slightly below normal temperatures
through Thursday. Then, an upper trough will pivot east across the
Great Lakes and push a back door cold front across central Indiana
early next weekend. Regional blend suggests there could be a few
showers and thunderstorms around over all or parts of the area
starting Thursday night and continuing through Saturday, when the
front will likely move through. Temperatures should bounce back to
near normal with highs in the lower to mid 80s by Thursday or
Friday. Look for lows in the 50s Wednesday night and the 60s the
rest of the long term.
&&
.AVIATION /Discussion for the 261500Z TAF Update/...
Issued at 1012 AM EDT Sun Jun 26 2016
TAFs are in decent shape for the mid morning update and only making
subtle adjustments. Main change is to slow initial VCTS mention by
an hour or two this afternoon. Already seeing a few showers develop
in the warm humid airmass...but current hi-res guidance favors
isolated convection developing primarily after 17-18Z with more
substantial convection associated with the cold front set to impact
the terminals late afternoon and evening.
12Z discussion follows.
Good confidence in VFR conditions through much of the period except
MVFR and possibly IFR at times in thunderstorms. The first batch of
convection should move into the LAF and HUF areas after 14z and IND
and BMG after 15z as a warm front moves across the area. Then, a
more solid line will be dropping southeast over the terminals 21z
and later this afternoon near and just ahead of an approaching cold
front per the HRRR. The HRRR is currently handling the convection
rather well. Things will be winding down tonight after the cold
front moves through.
Winds will be south and southwest today and increase to around 10
knots 14z-16z. Winds near term will then become west and northwest 7
knots or less post frontal tonight.
&&
.IND Watches/Warnings/Advisories...NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/MK/JH
SHORT TERM...NIELD
LONG TERM...MK
AVIATION...MK/RYAN