Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/17/17
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
809 PM CDT Sun Jul 16 2017
.DISCUSSION...Updated grids to trim back precip chances through
overnight period. Despite a lingering shower over Starr County at
this time, will limit PoP to 20% all areas through 06Z, then only
increase to 30% along the coast from 06-12Z. Even with abundant
moisture evident (2.17" of PW on 00Z BRO raob), don`t think the
vort max drifting across the area overnight will be enough forcing
for scattered precip to re-develop (per upstream satellite
trends), except perhaps along the coast. 23Z HRRR supports this
idea, as well. Also updated hourly temps to better reflect
observational trends, especially out west where showers and storms
occurred earlier. All products updated and disseminated.
&&
.PREV DISCUSSION... /issued 638 PM CDT Sun Jul 16 2017/
DISCUSSION...Updated for latest aviation discussion below.
AVIATION...Late afternoon/early evening convection waning a bit
faster than anticipated, so will only hold onto mention of VCSH
until 02-03Z due to boundaries floating around, especially out
near MFE. VFR with light winds should prevail through mid-morning
on Monday, though a brief shower at BRO or HRL cannot be ruled
out. Pretty strong signal in the model guidance that another round
of scattered showers and thunderstorms will occur beginning
around mid-day tomorrow, as a mid-level disturbance drifts
westward across the region. Atmospheric moisture will be abundant,
and storm motions indicated on BUFKIT forecast soundings are less
than 10 knots during the afternoon, so periods of heavy rain are
possible. Have introduced PROB30 groups at all terminals to
account for this possibility; MVFR conditions are likely to occur
at times in the heavier showers and thunderstorms.
PREV DISCUSSION... /issued 313 PM CDT Sun Jul 16 2017/
SHORT TERM (Now through Monday night): Convection has initiated
along the seabreeze and also in the northern ranchlands this
afternoon. Thunderstorms should expand in coverage as abundant
tropical moisture surges northward ahead of a mid-level trough of
low pressure moving into South Texas off the Gulf waters. Current
model soundings show precipitable water values of 2 to 2.25" across
the area, so any thunderstorms that develop have the potential to
produce locally heavy rainfall. 12Z model guidance on PoPs still
differs slightly with the GFS output being significantly higher than
this time yesterday and the NAM being the driest. Decided to
increase PoPs only slightly for tonight into Monday with the tricky
part being determining what boundaries will be leftover tomorrow and
how much instability can recover. Regardless, the trough axis will
be moving overhead Monday afternoon with southeast flow aloft, which
should support another decent round of precipitation. Still think
the better chances overall will be in the northern areas where model
guidance shows several vorticity maxima moving across. If training
of showers/storms occurs or if storms become attached to slow-moving
boundaries, nuisance flooding of streets and low-lying areas will be
possible, especially across areas that are already well-saturated
from recent rainfall. Isolated amounts of 1 to 2 inches or even
locally higher cannot be ruled out.
LONG TERM (Tuesday through Sunday): A very broad mid-level height
pattern will straddle the Gulf and deep South Texas. High pressure
will remain king over the Gulf as well, supporting a weak to mdt
anticyclonic southeast flow. A mix of clouds and sun and near normal
to slightly above normal temperatures look probable. Isolated Gulf
showers will stand up along the way, as will an almost daily sea
breeze. A pulse of moisture moving up from the south may provide the
best chance of coastal convection on Wed, but each day will hold
some potential for an inland marching sea breeze. By mid-week a
slightly more enhanced ridge will build over the southern Plains,
which won`t do anything to enhance rain chances, but will help nudge
high temperatures up a couple of degrees moving into the end of the
week and the weekend. Low temperatures will range from the mid 70s
to near 80, while high temperatures will be mainly in the 90s to
near the century mark Tuesday and Wednesday, with peak upper values
creeping up to a few degrees above the century mark late in the
period, supporting associated heat index values up to around 105
degrees.
MARINE: (Now through Monday night): Surface high pressure over the
Gulf of Mexico will maintain light to moderate southeast winds with
low seas of generally under 3 feet through the period. The main
marine impacts will be from any showers and thunderstorms that
develop, which would produce locally higher winds and seas.
Tuesday through Friday: Broad high pressure over the Gulf will
support light to moderate winds, mainly out of the southeast, and
low to moderate seas. Occasional marine convection will develop.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
This product is also available on the web at:
HTTP://WEATHER.GOV/RGV
53-Schroeder/61
Area Forecast Discussion
National Weather Service Goodland KS
737 PM MDT Sun Jul 16 2017
.UPDATE...
Issued at 730 PM MDT Sun Jul 16 2017
Adjusted areal extent and timing of rainfall tonight based on
latest near-term data. RAP model seemed to have a decent handle on
current storm activity and had done well last night. The
frontogenesis in the 600-500mb layer and lift in the 310K through
325K levels indicate the storm activity will develop near the
CO/KS border early this evening and be in a north-south line. This
lines up well with the 500mb vorticity that will be rotating
around the center of the closed upper level low. The storms will
move little this evening, so wherever the storms form, they will
linger there for awhile. Have good confidence in the
location/timing of storms this evening, however confidence is
lower for overnight. Models are split with the storms either
tracking more north-northeast or northeast. Regardless of the
track the storm activity will gradually decline overnight as 500mb
vorticity declines. Will hold off making significant adjustments
to the rainfall chances for overnight to see how storms
develop/move, and see if the data comes into better agreement.
&&
.SHORT TERM...(This afternoon through Monday)
Issued at 204 PM MDT Sun Jul 16 2017
Plume of deep moisture continues to linger over our CWA (apparent
on WV imagery), with mid-upper low near CO border.
This afternoon-Tonight: Thunderstorm activity is already beginning
to redevelop along western edge of main instability/moisture axis
near the CO state line. Latest RAP analysis indicates SB CAPE in
excess of 2000 J/KG and supports ML CAPE increasing to this range
within the next few hours. Shear is very weak, so other than less
organized isolated stronger cells (marginal hail) main concern
continues to be hydro. MOdels show increasing forcing over our CWA
as a strong lobe of vorticity on back side of mid level
circulation rotates over our CWA this evening and overnight.
Result should be increasing coverage, though with CAPE decrease
during the evening hours, moderate to occasionally heavy showers
may be favored over thunderstorms. I adjusted PoPs/QPF with latest
short range consensus blends to match these trends.
Monday: Main mid-upper low should be northeast of our CWA, but
lingering forcing on back side of system may support continued
shower and thunderstorms chances in our northeast and east.
Moist/unstable air mass in the afternoon could support isolated
activity further west near building surface trough, but current
guidance is favoring our east with possible subsidence in our west.
Bulk effective shear should be near or just above 30kt, so with
better shear we may have a better chance for severe thunderstorms in
our far northeast than we have had over the past few days.
Regarding temperatures: As has been the case, cloud cover and
linger precip complicate overnight lows, with locations that
clear out dropping to near 60F (more likely west). Otherwise,
where precip lingers overnight lows may not drop much lower than
the upper 60s/near 70F. With mid-upper low exiting and surface
trough building in our west we should see WAA through the day
Monday. This will support highs in the 90s, with a few locations
possibly reaching the 95-98 range assuming good clearing/mixing.
.LONG TERM...(Monday night through Sunday)
Issued at 204 PM MDT Sun Jul 16 2017
Monday night-Tuesday: Shortwave transverses the area bringing a
chance of showers and storms Monday evening and overnight. Ridging
aloft begins to build as high height center will be over the area.
May see a few pop up showers over northern portions of the area
Tuesday afternoon. Highs will be above normal with most locales in
the upper 90s and low 100s.
Wednesday-Thursday: Upper level ridging dominates the weather
through the period. Models in good agreement that these two days
will be the hottest of the week. Heat indices will be near or above
105F for areas east of Highway 83. May see a few storms develop over
parts of our CO counties during the late afternoon to early evening
on Thursday.
Friday-Sunday: Models are not in particular good agreement for this
coming weekend. Upper level ridging begins to progress to the east
of the CWA on Friday. Zonal flow follows on Saturday. Looks as
though there will be a chance of rain each day. GFS is advertising a
similar setup as the one that has affected the CWA the past few
days, with an upper low meandering towards the area from CO on
Sunday bringing good chances of rain and plenty of cloud cover.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 519 PM MDT Sun Jul 16 2017
VFR conditions forecast for the TAFs. Main focus will be the
timing of storms that will move over KGLD this evening. Based on
how well the model data has performed the last two nights, am not
too confident with the exact timing of the rainfall for KGLD.
Based on latest data, am confident rainfall will be over the site
during the latter half of the evening, but confidence lowers in
regard to the begin/end of the rainfall. Any rain that moves
overhead will likely be moderate, possibly heavy. KMCK should have
rain move over the site in the overnight hours.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...SME
AVIATION...JTL
Area Forecast Discussion
National Weather Service Green Bay WI
601 PM CDT Sun Jul 16 2017
Updated aviation portion for 00Z TAF issuance
.SYNOPSIS...
Issued at 228 PM CDT Sun Jul 16 2017
Quiet weather through Monday, then more humid with thunderstorms
returning mid-week.
The westerlies across southern Canada and the northern CONUS will
deamplify and become progressive the next few days. Agreement
among the medium range models begins to break down after that,
but the pattern will probably trend back to one with a ridge in
the west and a trough in the east, though perhaps with less
amplitude than we`ve seen recently.
The period will begin with seasonably cool air and low humidities,
but warmer and more humid conditions will return fairly quickly.
Once in place, those conditions are likely to linger for the rest
of the period, albeit with some day to day variation.
As typical for this time of year, precipitation totals will
depend on the movement of individual convective systems. But the
overall pattern looks to support enough opportunities for
precipitation to result in above normal amounts for the period.
&&
.SHORT TERM...Tonight and Monday
Issued at 228 PM CDT Sun Jul 16 2017
The latest RAP analysis and satellite/radar imagery show high
pressure centered over Lake Superior early this afternoon. Very dry
air is associated with the high, with pwats falling to 0.5 inches.
As a result, skies have been gradually clearing from north to south
today, though scattered to broken ceilings are hanging on over
central and east-central WI. There too, skies should turn mostly
clear by the end of the afternoon. As high pressure slides south
into the area, temps and fog potential are the main forecast
concerns.
Quiet weather is expected over the next 24 hours, thanks to high
pressure building southward across the central Great Lakes. Very
dry mid-level air beneath the ridge axis will accompany the high,
leading to mostly clear conditions over the period. As winds fall
off tonight, some potential for ground fog formation after midnight
due to min temps projected to fall below the cross-over temp.
Statistical guidance is not bullish on fog potential, so kept the
patchy wording over the sandy soil areas, like the previous forecast
showed. Cool lows tonight ranging from the mid 40s to mid 50s.
Highs will be several degrees warmer than todays readings, and range
from the mid to upper 70s.
.LONG TERM...Monday Night Through Sunday
Issued at 228 PM CDT Sun Jul 16 2017
Though models differ on the details, there is likely to be a
round of convection as a frontal boundary crosses the area sometime
around Tuesday night. That will probably be followed by a lull in
the rain chances, though by then the models were sufficiently
different that the blend of guidance used to initialize the
forecast ended up with chance/slight chance PoPs for at least a
portion of the area. Additional rain chances will occur during the
remainder of the forecast as shortwaves in the flat upper flow
interact with the frontal zone to our south. The front appears to
be far enough south so that the heaviest rain and greatest
flooding potential will remain south of the area, but that will
certainly need to be watched closely in the coming days.
No significant chances were made the forecast initialization
generated from a broad-based blend of guidance products.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 601 PM CDT Sun Jul 16 2017
Mostly clear skies and light winds have settled in across the TAF
sites as high pressure builds in across the region. These
conditions are expected to last through Monday. The one main issue
could be ground fog formation late tonight into early Monday
morning. MOS guidance does not support much in the way of fog,
therefore will maintain the patchy mention of fog over the sandy
soil areas of northern Wisconsin with this issuance.
&&
.MARINE...
Issued at 228 PM CDT Sun Jul 16 2017
Winds and waves are both marginal for the small craft advisory
this afternoon. With a few gusts still occurring above 20 kts and
Minneapolis Shoal light around 25 kts, will keep the advisory and
beach hazard statement going into the evening. Most gusts should
remain at least into the 15-20 kts range through midnight.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
Beach Hazards Statement until 10 PM CDT this evening for WIZ050.
&&
$$
SYNOPSIS.......Skowronski
SHORT TERM.....MPC
LONG TERM......Skowronski
AVIATION.......Kurimski
MARINE.........MPC
Area Forecast Discussion
National Weather Service North Platte NE
657 PM CDT Sun Jul 16 2017
.SYNOPSIS...
Issued at 306 PM CDT Sun Jul 16 2017
A closed upper low was analyzed in east central Colorado at 20z.
Thunderstorm activity still at a minimum with only isolated storms
from extreme east central Colorado into extreme southwest
Nebraska. A rather large cumulus field however across the region.
Valentine has once again reached 100 degrees as of 20z. This is
the third day in a row, and the 7th time this month Valentine has
reached or exceeded 100. Valentine is also been very dry so far
this month with 0.10 recorded on July 3rd, and only a trace on two
other occasions, attributing to the heat.
&&
.SHORT TERM...(This evening through Monday)
Issued at 306 PM CDT Sun Jul 16 2017
Tonight...A closed low center over the CO-NE-KS border will lift
slowly into southwest Nebraska overnight. This will bring
increasing chances for showers and thunderstorms to southwest
Nebraska. The RAP and HRRR model both indicate precipitable water
values increasing to 1.5-1.75 inches, which is overdone slightly,
but indicates the anomalously high moisture available. Winds at
850 mb increase to 30 kts and as Shown by the NAM bufkit, deep
warm rain processes indicate to potential for heavy rainfall
developing late tonight. On Monday, this closed low will be the
main weather feature, with abundant moisture and chances for
precipitation up to 50 percent from southwest into central
Nebraska thorough the day. The NAM remains slightly faster with
this system than the GFS, and accounted for a slower solution.
Given the model QPF output, locally heavy rainfall is suggested.
Abundant cloud cover from southwest through central Nebraska will
also hold back highs to the upper 80s. To the west and north,
highs will reach the low to mid 90s. greater instability to also
support isolated storm development across northern Nebraska in
the afternoon. Much of western Nebraska will be in a marginal
risk area, with marginally severe hail and wind gusts possible.
.LONG TERM...(Monday night through Sunday)
Issued at 306 PM CDT Sun Jul 16 2017
The closed low will become an open wave as it moves into eastern
Nebraska overnight. Still a good chance for thunderstorms across
the eastern zones Monday evening. Other thunderstorms are likely
to develop in the panhandle and southwestern South Dakota and move
into the northwest Sandhills as well. Heating back up Tuesday, as
the upper ridge oriented west to east from the Four Corners
through the Central Plains bring highs back into the mid and
upper 90s. A weak front to bisect the area Tuesday afternoon and
evening for a focus for thunderstorms to develop on with stronger
winds aloft in place across the Northern Plains. There will again
be a marginal risk area, north of I80, where marginally severe
hail and wind gusts are possible.
Wednesday shaping up to be the hottest day of the week, as the
upper ridge intensifies across the Central Plains, and the
frontal boundary lifts north into South Dakota. Most area are
likely to reach 100 degrees, with southwest Nebraska into the
central sandhills reaching as hot as 105. A chance for
thunderstorms Wednesday evening across north central Nebraska,
which will be on southern periphery of the upper ridge.
There will chances for thunderstorms over portions of the
forecast area each day Thursday through Sunday. The main upper
ridge will migrate into the Southern Plains and southeastern U.S.,
and bring monsoonal moisture into the region. The northern stream
will become more active, and bring better chances for thunderstorms
late afternoon and overnight each day. Highs to remain above
normal Thursday and Friday from 92 to near 100 degrees, then lower
90s Saturday, and upper 80s by next Sunday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 656 PM CDT Sun Jul 16 2017
For the KLBF terminal, expect partly to mostly cloudy skies
overnight as a weak upper level disturbance lifts slowly east
into southwest Nebraska. Light rain showers with embedded
thunderstorms will be possible late Monday morning into the
afternoon hours. With isolated coverage expected and some timing
differences within the models will handle the mention of tsra
with a vcts group. For the KVTN terminal, expect clear skies
mainly with some few to scattered high clouds developing overnight
over northern Nebraska. Cloudiness should persist into Monday
with scattered clouds at 20000 FT AGL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Roberg
SHORT TERM...Roberg
LONG TERM...Roberg
AVIATION...Buttler
Area Forecast Discussion
National Weather Service Omaha/Valley NE
603 PM CDT Sun Jul 16 2017
.SHORT TERM...(Tonight through Wednesday)
Issued at 330 PM CDT Sun Jul 16 2017
The main forecast issues in the short term will be chance for
thunderstorms...temperatures...and heat headlines.
The latest surface map had temperatures again in the 90s with a
weak surface boundary near Norfolk to Harlan where readings were
closer to 90. Heat index values are mostly 95 to 100...however
local conditions has them variable with some high and some lower.
Visible satellite imagery had a few cumulus in our area with a
few thunderstorms in southeast Iowa and west central Iowa closer
to where a shortwave is passing through the region. WSR-88D radar
reflectivity shows thunderstorms in the upslope region in
northeast CO and near Ottumwa and southeast Iowa.
The main storm track for the short term will be over the Northern
Plains, however a pesky area of low pressure in the mid levels
currently over eastern Colorado is forecast to drift eastward
during that time. Water vapor satellite imagery does a nice job
depicting the ridging across the central U.S. into Canada and
shows the moisture over parts of the southwest U.S. into
CO/western Kansas.
The 12Z OAX sounding this morning had 1.13 PWAT. PWAT values in a
narrow area into to 1.25" then drop for Monday ahead of the
moisture with the pesky low.
The RAP has been overdoing the precip today and the HRRR/RAP try
to build echoes back toward southwest Iowa late this afternoon.
The satellite shows a few cumulus from Pottawattamie Co. eastward
and could see something isolated develop. For now will leave dry
and pass on to the evening shift to metwatch.
As the H5 trough breaks down the ridge over the Northern
Plains...the H5 low press drifts into western Nebraska Monday
morning and central/parts of northeast and east central Nebraska
Monday afternoon. Outside of the clouds...southwest flow and very
warm h85 temperatures should keep highs in the 90s. Isolated
thunderstorm chances will spread into northeast Nebraska by 00Z
with chance pops overnight for all but southeast Nebraska and
southwest Iowa. Rain chances linger for Tuesday and Tuesday night,
however the coverage appears better to the north of the area. The
lingering clouds could hold temperatures back, however with the
main front still to the north...have highs again in the 90s.
Hot temperatures return for Wednesday and highest heat index
values from 100 to 110. Considered an excessive heat watch,
however with isolated to scattered showers and thunderstorms in
the forecast Monday night through Tuesday night and this
convective activity could affect boundaries and where the highest
heat would be later in the week, decided to hold off.
.LONG TERM...(Wednesday night through Sunday)
Issued at 330 PM CDT Sun Jul 16 2017
A large area of low pressure is forecast to encompass Hudson Bay
with a faster flow across the Northern Plains and a large area of
h5 pressure over the central and southern U.S. Hot temperatures
are forecast for Thursday and there is still some timing issues
related to ripples in the flow across the Northern Plains which is
forecast to bring some relief from the heat this weekend along
with spotty chances for rain.
Highs Thursday and Friday 89 to 100 and 85 to 95 for the weekend.
Highest heat index values could range from 100 to 105 Thursday and
Friday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 602 PM CDT Sun Jul 16 2017
VFR conditions are forecast through Monday evening with only
scattered high clouds and light southeast to south winds under
10kt.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
SHORT TERM...Zapotocny
LONG TERM...Zapotocny
AVIATION...Dergan
Area Forecast Discussion
National Weather Service Reno NV
232 PM PDT Sun Jul 16 2017
.Synopsis...
Buildups with isolated thunderstorms are expected this afternoon
and evening over the eastern Sierra into central Nevada. Low
pressure approaching the west coast will increase winds Monday and
Tuesday, leading to critical conditions for rapid fire spread.
Decreased winds with hot temperatures are forecast for the balance
of next week, with isolated storms confined to mountain areas.
&&
.Discussion...
* Thunderstorm Trends: Isolated storms remain in the forecast
through this evening following latest HRRR guidance. Satellite
showing decent buildups over higher terrain from Alpine Co south
and eastward into central Nevada. This is the area we`re
watching for possible storms. No severe nor flash flood storms
expected but new fire starts from lightning and strong outflow
winds are possible. Airmass dries out and stabilizes starting
Monday as southwest flow aloft increases. This should push storm
chances out of our region through at least Wednesday.
* Radar Status: The Reno KRGX radar is inoperative until further
notice. An apparent motor failure is being investigated by
technicians this afternoon. We`ll hopefully have a better handle
on when the radar will return to service then. Use of
surrounding radars such as Sacramento or Elko may help but
details won`t be as clear over our region. GOES-16 data and
lightning networks will prove useful for storm monitoring this
afternoon.
* Increased Winds Monday, Tuesday: Low pressure off the Pac NW
will yield increased southwest flow aloft and stronger than
normal mid-summer winds early this week. While not terribly
impactful for travel, this could be a big scenario for fire. See
fire weather section for more details. Choppy waters will be
encountered on most area lakes, so Lake Wind Advisories will be
posted for Monday.
* Storm Trends Late Week: High pressure will build back over the
region bringing generally quiet and hot weather through next
weekend. But not excessively hot. Isolated storms could return
to the Eastern Sierra starting Thursday afternoon. GEFS/ECMWF
simulations continue to suggest a big monsoon moisture push into
our region early-mid next week. This would result in more
widespread thunderstorms and a possible flash flood scenario,
something we haven`t seen much of so far this summer. Confidence
remains mixed but worth monitoring.
-Chris
&&
.Aviation...
* Areas of haze and smoke from Long Valley fire earlier resulted
in MVFR visibilities around RNO and RTS. With now increasing
winds and mixing visibilities will steadily improve. Typical
afternoon and evening westerly winds today will transition to
northwest overnight. This could lead to smoke and haze back into
RNO/CXP vicinity by daybreak Monday. Surface visibility
restrictions should be MVFR at worst with slantwise visibility
being poorer.
* Isolated storms remain possible this afternoon-evening, mainly
for areas south of TVL-CXP-NFL line into the Eastern Sierra
(MMH). Based on latest HRRR guidance and satellite trends this
looks reasonable. Note that Reno RGX radar is out of service
until further notice so radar data over the region will be
degraded.
* Low pressure approaching Pac NW early this week. Increased
west/southwest winds Monday and Tuesday likely to yield some
turbulence and localized wind shear. Could impact fire air
support ops. Gusts on the order of 30-35 kts likely including
RNO/CXP and Long Valley Fire area each afternoon and evening.
Not a huge wind event but there will be some bumps.
-Chris
&&
.Fire Weather...
The forecast remains on track for an extended period of fire
weather concerns through about mid-week. Gusty winds and very low
RH will combine to create critical fire weather conditions Monday
and Tuesday with a more marginal, but non-zero, risk Wednesday.
Monday`s conditions continue to pose the largest concerns with a
projected 9-12 hour period of critical fire weather conditions. A
trough dropping out of the Pacific Northwest will strengthen the
wind field with gusts expected in the 30-40 mph range. Winds
linger into the overnight hours especially along upper slopes and
ridges. A significant dry slot will also accompanying this trough
resulting in lower than usual afternoon humidity, 4-10% in western
Nevada, and abysmal overnight recoveries. Downwind of existing
wildfires, like the Long Valley and MM155 fires, Sutcliffe and
Grass Valley south of Winnemucca are in a higher threat area. This
is a particularly dangerous situation where fire spread rates may
greatly exceed fire protection ability. You may have very little
time to leave, so it is best to heed any evacuation orders.
Winds increase again Tuesday afternoon to a slightly lesser
degree, gusts 25-35 mph, as the pressure gradient remains
relatively tight. Hours under red flag conditions decreases from
Monday to 3-7 hours Tuesday. As such, the Fire Weather Watch has
been upgraded to a Red Flag Warning. Any active fires will
intensify once again reducing the effectiveness of fire
suppression measures.
Winds Wednesday have been subtly increasing each new model run.
Concerns are increasing, but no watches or warnings have been
issued yet. Some of the higher slopes and ridges will briefly meet
critical thresholds, but the duration is currently projected to
be only around a couple of hours. Overall, conditions are expected
to be more marginal. However, as we have seen this season, fires
involving grasses and sage will be very active even in marginal
conditions.
Finally, smoke and haze around the Reno Metro area has been
reducing Air Quality during the overnight and morning hours
beneath nocturnal inversions. Recent readings in Reno have shown
that air quality has degraded into the "Unhealthy for Sensitive
Groups" rating. Locations closer to active fires, like Palomino
Valley and Pyramid Lake, will have worse conditions. As long as
fires are burning in close proximity to Reno and other populated
areas, expect poor to moderate air quality. Boyd
&&
.REV Watches/Warnings/Advisories...
NV...Red Flag Warning from noon to 8 PM PDT Monday NVZ450-453-458-459.
Red Flag Warning from noon to 8 PM PDT Tuesday
NVZ450-453-458-459.
Lake Wind Advisory from noon to 8 PM PDT Monday NVZ002>004.
CA...Red Flag Warning from noon to 8 PM PDT Monday CAZ270-271-278.
Red Flag Warning from noon to 8 PM PDT Tuesday CAZ270-271-278.
Lake Wind Advisory from noon to 8 PM PDT Monday CAZ071>073.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
Area Forecast Discussion
National Weather Service Tallahassee FL
802 PM EDT Sun Jul 16 2017
.UPDATE...
We saw an early start and early exit of widespread convection
across our CWA today. Only very light patches of rain remain so
will leave low PoPs up until 06z. Thereafter, we could see
convection moving in from the west across the Florida Panhandle
prior to daybreak. Otherwise, mostly cloudy overnight with lows in
the lower 70s.
&&
.PREV DISCUSSION [729 PM EDT]...
.NEAR TERM [Through Tonight]...
Scattered to numerous showers and thunderstorms will continue into
the early evening hours and then gradually diminish. A few strong to
marginally severe storms cannot be ruled out given decent mid-level
lapse rates and strong instability, mainly across the northern and
eastern halves of the area which haven`t been worked over yet with
prior convection.
Late tonight, a decent chunk of the CAM guidance indicates some
redevelopment of convection along the panhandle coast. The HRRR has
been very persistent in showing this scenario through at least its
16z run today. If this scenario were to pan out, then localized
heavy rain could be a threat along the panhandle coast late tonight
into Monday morning with PWATs near 2 inches and weak steering flow.
This will be something to keep an eye on in the model guidance
during the evening hours. Overnight lows will generally be in the
low to mid 70s across the area.
.SHORT TERM [Monday Through Tuesday Night]...
Mid and upper level troughing over the eastern CONUS today will
deepen, extending south into our local area. With deep layer
southwest flow, our already juicy atmospheric column will see an
increase in deep layer moisture. Model PWATs climb above 2" across
our area Monday. A stalled frontal boundary over northern MS/AL/GA
will be dragged southward as the mid/upper level trough deepens into
the southeastern CONUS. This forcing, along with diurnal heating
which will increase instability and help initiate a seabreeze, will
be plenty to initiate convection tomorrow. Expect scattered to
numerous storms across the area, similar to today. With rich Gulf
moisture in place and moderate instability, some of these storms
could produce heavy rain and gusty winds.
On Tuesday, the trough will lift northeastward, moving the front
further away from our area. The greatest chances for storms on
Tuesday will be in south central GA and the eastern FL Big Bend.
Overall moisture will be decreasing, but heavy rainfall and gusty
winds will still be possible.
.LONG TERM [Wednesday Through Sunday]...
The mid and upper level trough will continue to lift northeastward,
allowing ridging to build in aloft. Daily chances for scattered
afternoon thunderstorms remain in the forecast through the weekend,
though storms are expected to be mostly focusing over north FL.
Highs will be in the low to mid 90s and lows will be in the low to
mid 70s.
.AVIATION [Through 00Z Tuesday]...
VFR conditions are expected outside of thunderstorms. However
patchy fog is possible in the late night/early morning hours. Any
fog will likely be MVFR and a temporary condition. Showers and
thunderstorms will be widespread on Monday and will likely start
early again. Showers and thunderstorms will move inland from the
Gulf starting in the early morning at ECP. By late morning
activity will be increasing near DHN and TLH. ABY and VLD will see
increasing activity by early afternoon. Winds will be mainly
light with gusty winds possible in and near thunderstorms.
.MARINE...
Outside of daily chances for showers and thunderstorms, winds will
be around 10 knots or less through the week. Seas will be low as
well, 2 feet or less through the period.
.FIRE WEATHER...
Wet conditions continue for most of the region. Dispersion indices
will be low on Monday, under 20 during the daytime in parts of SE
Alabama and SW Georgia.
.HYDROLOGY...
A disturbed pattern will remain in place early this week, causing an
increase in chances for showers and thunderstorms through Tuesday.
While widespread rainfall accumulations are expected to fall around
the 1 to 2 inch range, there is the potential for 3 day totals
closer to 4 to 6 inches. At this time, rivers are low enough to not
warrant concern for river flooding from this heavy rain, but
localized flooding will be possible for the next few days.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 73 87 74 89 74 / 20 60 20 60 20
Panama City 77 85 76 86 77 / 50 60 30 50 20
Dothan 72 86 73 88 73 / 30 60 20 50 20
Albany 72 88 73 89 73 / 30 60 30 50 30
Valdosta 72 89 73 91 73 / 30 70 30 70 20
Cross City 73 89 73 91 73 / 20 50 20 40 20
Apalachicola 76 85 76 87 76 / 30 40 30 50 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
UPDATE...Barry
NEAR TERM...DVD
SHORT TERM...Moore
LONG TERM...Moore
AVIATION...McDermott
MARINE...Moore
FIRE WEATHER...McDermott
HYDROLOGY...Moore
Area Forecast Discussion
National Weather Service Tucson AZ
824 PM MST Sun Jul 16 2017
.SYNOPSIS...Expect scattered to numerous thunderstorms through the
evening and overnight hours...followed by widespread showers with
embedded thunderstorms Monday. Heavy rainfall will occur with the
stronger thunderstorms. Isolated to scattered mainly afternoon and
evening thunderstorms will then prevail Tuesday into next weekend.
&&
.DISCUSSION...
Another complicated forecast for this evening as earlier convection
was rather scattered/disorganized in nature, save for the few storms
that caused damage on the west side of Tucson around 5 pm. Most
storms managed to die off around 7pm but there has been quite a bit
of new development across the area just within the past few minutes.
A massive complex continues to dive southward out of Coconino and
Yavapai Co`s with other complexes forming over
Pinal/Graham/Greenlee Co`s. This is well forecast by the
HRRR, UA WRFs, and the HRRRx with nearly all CAM`s indicating the
show is only beginning at this point. Nearly all models show
converging complexes this evening but the big question is will this
cluster move through Tucson, or perhaps stay to the northwest.
Conflicting signals in the models but at this point it appears the
HRRR may be a bit too far east with its solution based on current
radar trends. Correcting for this would take the bulk of any new
activity west of Tucson but that`s hardly to say that Tucson is in
the clear. PoPs have been raised in nearly all locations overnight.
Regardless of where cell mergers take place, PSR and TWC 00Z
soundings reveal a considerable amount of instability above 600-
700mb. BL below those levels appear to be relatively stable but
these soundings are more than suggestive of long lived storms
due to elevated instability through much of the night. Suffice to
say the Flash Flood Watch will remain in effect untouched as hydro
concerns will be front and center for the rest of the night.
&&
.AVIATION...Valid thru 18/06Z.
Bit of a break this evening but additional TSRA/SHRA expected late
tonight into early Monday morning. Storms shouldn`t be severe but
will be heavy rainers with brief periods of MVFR or even IFR
cigs/vsbys possible. A bit of a break around daybreak but conditions
will deteriorate once again Monday afternoon. Otherwise, VFR
conditions with surface wind variable in direction mainly less than
12 kts. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Scattered to numerous showers and thunderstorms
mainly during the afternoon and evening hours through Tuesday.
Somewhat less coverage of thunderstorms should occur west of Tucson
later this week. However, ample moisture will still produce isolated
thunderstorms west of Tucson with scattered thunderstorms from
Tucson eastward Wednesday into next weekend. Daytime temperatures
will be at least a few degrees below seasonal normals this week.
&&
.PREV DISCUSSION...
Starting up nicely today with fat juicy storms. Watch for potential
underestimation of precip by radar. Another outflow trying to push
southwest out of the Rim country, but heavy precip is shaping up as
our biggest concern.
Plenty of moisture, a decent easterly component to our flow, and
the proximity of a weak inverted trough immediately east and
southeast of the area will continue this busy thunderstorm period.
Precipitable water ranging from 1.45 to 1.7 inches across the
area with surface dew points in the mid to upper 60s. The 12Z KTWC
sounding showed plenty of conditional instability and favorable
conditions for strong outflows from the northeast and east. We
will continue to be vulnerable to organized thunderstorm activity
from afternoon to late evening hours. With the proximity of the
inverted trough and weak easterly impulses combined with a steady
flow, we will also tend to reload the atmosphere more quickly than
usual between event periods.
Flash Flood Watch through Monday evening, and another day with
marginal severe from SPC looks good.
Monday looks like a good chance of precip, but with the strong
potential for another overnight period, and possibly extending
into the morning hours, what form will it take? Right now the bet
is for scattered showers with embedded thunderstorms and a
continued heavy rain threat. We could reset once again for another
solid thunderstorm day though.
Depending on timing of activity over the next 36 hours, Tuesday
could be down as we work through what`s left of the inverted
trough.
Beyond that, it doesn`t really look like it`s going to let up,
with high pressure in a favorable position to continue to allow a
deep fetch of moisture into the area along with keeping things
open for easterly wave activity.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through Monday evening for AZZ501>515.
&&
$$
Leins/Meyer/Zell
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Las Vegas NV
855 PM PDT Sun Jul 16 2017
.SYNOPSIS...Isolated to scattered thunderstorm activity can be
expected the next several afternoons particularly across Southern
Nevada and Northwest Arizona, with temperatures gradually cooling to
near seasonal normals. By Tuesday evening, deeper moisture will
begin to push in with widespread clouds and showers possible
Wednesday. Moisture looks to linger through the weekend with near
daily thunderstorm chances and slightly above normal temperatures.
&&
.UPDATE...Convection still holding together across portions of
Lincoln, Clark and Mohave Counties this evening as forecast. Due to
outflow boundary interactions, I hesitate to remove mention of
thunderstorms in any particular area for the rest of the evening and
no updates are planned. - Harrison-
&&
.PREV DISCUSSION...
210 PM PDT Sun Jul 16 2017
.SHORT TERM...thru Tuesday Night.
Moisture surge last night has worked to subdue the afternoon
temperatures rise this afternoon with current temperatures across
the region running between 4 and 6 degrees cooler than this time
yesterday but dewpoints 12-18 degrees higher...particuarly from Las
Vegas east. Thus far, thunderstorm development has remained
isolated and terrain driven but a few more degrees of heating should
spark a marked increase in development later this afternoon. In
fact, SPC mesoanalysis suggests over 1500 J/Kg of CAPE across most
of Clark and Mohave counties, which would suggest potential for some
intense updrafts and rapid storm development once that instability
can be realized.
The HRRR has been fairly consistent indicating isolated to scattered
storms across Clark county this afternoon, with more robust activity
across Mohave county. Will also need to watch activity in SW Utah as
it may congeal and push south late this evening into eastern Clark
and northern Mohave counties. Overall, I expect a relatively active
evening across the region with things tapering off late this
evening. Similar conditions will be in play tomorrow, so I expect a
general repeat of things today.
On Tuesday, forecast soundings illustrate some warm air aloft moving
in which may suppress activity during the day, however, an inverted
trough moving in midweek will begin to make its approach Tuesday
night with a substancial increase in moisture content moving in.
This may result in a complex of nocturnal storms along the leading
edge of this gradient, or it may work in more gradually in the form
of light showers and clouds. Either way, low PoPs were continued
through the nighttime hours Tuesday night ahead of this moisture
increase.
&&
.LONG TERM...Wednesday through Saturday. A little better run to run
consistency this morning, although model to model consistency still
isn`t the best. Forecast confidence is about average. The main focus
is on Wednesday, as the models still agree to some extent on an
inverted trough rolling west across the Gulf of California on
Tuesday, eroding the western extent of the ridge and sending a push
of moisture into the region on Wednesday. This should result in an
increase in PoPs and decrease in temperatures, at least for the
eastern half or so of the area (and possibly farther west depending
on exactly how the details evolve). Confidence is lower for Thursday
through Saturday, but there should be enough moisture available for
thunderstorm chances each day, at least for areas near and east of
Las Vegas. A bigger question is whether the clouds and storms will
keep temperatures down or whether there will be enough breaks of
sunshine to allow for a rebound. MOS guidance has trended down quite
a bit for those days, and nudged the forecast in that direction.
These cooler temperatures may also suppress thunderstorm development
Wednesday and result in more gloom than boom. &&
.AVIATION...For McCarran...Southeasterly winds this afternoon will
shift to the southwest this evening and tonight remaining around 10
knots or less. Isolated showers and storms cannot be ruled out
around KLAS this evening and Monday afternoon/evening but confidence
is low in this activity directly affecting the terminal so have not
included in current TAF package. More than likely brief erratic wind
shifts and gusts will be possible as outflow boundaries move through
the valley during these times. Light and variable winds Monday
morning will increase once again out of the south to southwest
throughout the afternoon remaining primarily between 10-15 knots
through Monday night.
For the rest of southern Nevada, northwest Arizona and southeast
California...South to southwest flow will prevail across much of the
area today and tomorrow with gusty winds of 20-25 knots possible
along the Colorado River Valley each day. Highest coverage of
showers and storms today and tomorrow will be across Mohave,
Lincoln, and Clark counties, especially across the higher
elevations. Monday will see chances for isolated showers and storms
spreading westward into San Bernardino, Nye, and Inyo counties. Any
shower/rain activity could create gusty erratic winds and heavy
downpours. This increase in moisture will also bring increasing
mid/high cloud cover across a majority of the area.
&&
.FIRE WEATHER...Increased moisture will result in isolated to
scattered thunderstorm activity for the next few afternoons
especially across southern Nevada and Northwest Arizona. On Tuesday
evening...clouds and moisture levels will increase further with
widespread showers and abundant clouds expected Tuesday night and
Wednesday across Northwest Arizona and Southern Nevada. Drier
conditions are expected further west across the Sierra and Western
Mojave desert but isolated storms will remain possible. Temperatures
will be gradually cooling through the week...with the coolest day
looking like Wednesday.
&&
.HYDROLOGY...Creeks, streams and rivers in northern Inyo County
continue to run high and fast from snow melt. Some road closures
continue in the area. Bishop Creek Bypass and Big Pine Creek Bypass
continue to be utilized to minimize flows through Bishop and Big
Pine. Isolated thunderstorms over the mountains may aid snowmelt
runoff and keep some drainages elevated over the coming days as
well. Remember, never drive through flooded roadways or around
barricades. Also, pastureland or farmland adjacent to creeks,
streams or rivers could experience areas of standing water.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
SHORT TERM/FIRE WEATHER...Outler
LONG TERM...Morgan/Outler
AVIATION...Guillet
For more forecast information...see us on our webpage:
http://weather.gov/lasvegas or follow us on Facebook and Twitter