Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/09/17
Area Forecast Discussion
National Weather Service Des Moines IA
606 PM CDT Sat Jul 8 2017
...Updated for 00z Aviation Discussion...
.SHORT TERM.../Tonight through Sunday/
Issued at 324 PM CDT Sat Jul 8 2017
Northwest flow continues over Iowa during the short term with
several embedded and weak shortwaves riding through the flow. At
the surface, high pressure will continue to slide off to the
southeast with the axis of the high roughly from Marshall MN to
just west of Mason City to Cedar Rapids then southeast. A surface
low has developed over central NE with a weak surface
trough/boundary extending into west central IA then into south
central IA. Though moisture is lacking we are moderately unstable
with CAPE`s increasing to 2200 J/Kg this afternoon and maintaining
1000 J/Kg overnight. The models yesterday had accurately depicted
an area of lift coincident with this weak surface boundary and a
mid level cloud field developed, along with a few sprinkles from
west central into south central Iowa.
During the evening this area of lift will shift into south
central/southeast IA again, coincident with the weak surface
boundary. The lift will be amplified to some degree by a weak
shortwave passing through mid to late evening which could produce
additional light showers or an isolated thunderstorm. This
activity, should it develop, would pass to the southeast later
this evening leaving the remainder of tonight dry but a little
muggy as dewpoints increase solidly into the mid 60`s.
There is a couple of items of concern for Sunday. First, the
models have consistently developed an MCS over MN tonight and
drop it southeast through Sunday morning. Past runs have scraped
NE IA with this system through mid Sunday morning but latest runs
now carry it well NE of the forecast area. While the trend was
good, the chance for storms will still need to be watched based on
where the storm complex develops and moves to, as the HRRR still
has some semblance of precip scraping far NE IA.
As the day progresses the surface low to the west will lift into
South Dakota with a boundary extending across MN and WI. The weak
surface trough over the East will evolve into a warm front as
southwesterly winds increase and deepen. Meanwhile another
shortwave will cross Iowa and if the timing is right, will
interact with the frontal boundary and aid in the development of
thunderstorms across eastern IA from mid to late afternoon into
the evening. Models definitely depict a ribbon of theta-e
advection along/ahead of this boundary and given the instability
and DCAPE`s of 1500 J/Kg, some severe storms with damaging wind
will be possible. LCL`s appear too high for much of a tornado
threat...at least through 00Z. Shear values are best further north
where the main boundary will be but are more modest over Iowa so
at this point, I`m not real excited about large hail. However, if
that warm frontal boundary over eastern Iowa is stronger than
forecast, then shear would be much better and hail would have to
be considered as a threat.
Similarly to tonight, if storms do develop late day across the
east, then they will likely intensify Sunday night as a low
level jet increases some but should likely be further east of our
forecast area.
.LONG TERM.../Sunday night through Saturday/
Issued at 324 PM CDT Sat Jul 8 2017
The main forecast concern was focused on severe weather potential
late Sunday night into Monday and with the heat building back
into the region throughout the week. Models are in good agreement
with the timing and location of shortwave to impact eastern Iowa
tomorrow night into Monday and utilized a blend.
Sunday night into Monday morning...Shortwave embedded within the
500mb northwest flow pushes southeast across southern Minnesota
into northeast Iowa/northern Illinois between 06-12z Monday.
Instability during this time should still be fairly good with
MUCAPE values in the northeast ranging in 2000-3000 J/kg and
SBCAPE around 2000 J/kg. DCAPE ranges in the 700-1000 J/k and low
to mid level lapse rates in the 7.5 to 8 C/km range per MCW
sounding by around 06-09z Monday. 0- 3km shear tops out at 40-50
knots and 0-6km shear over 50 knots tomorrow night per GFS across
northeast portions of the forecast area. Mainly unidirectional
shear profiles tomorrow night, especially when the shortwave moves
across eastern Iowa. Mainly expecting a damaging wind and large
hail threat. Storms look to be east of the forecast area by 12-15z
and certainly confident enough to increase pops in the Slight
Risk area.
Monday afternoon through Friday...The heat and humidity build back
into the region beginning Monday with highs along and south of
Highway 30 likely to be in the 90s for several days. Dew points
back into the lower 70s for much of the state should cause for
some very uncomfortable heat conditions for an extended period.
Heat index values in the afternoon look to top 100 degrees with
the hottest day appearing to be Wednesday with mid-90s for
temperatures and near 105 heat index readings for the southern
half of the forecast area. If storms and cloud cover clear out
quick enough on Monday, the temperatures/humidity will have a
chance to recover even more so than the current forecast. Some
relief is possible with a pop-up thunderstorm Tuesday afternoon
and Thursday.
&&
.AVIATION.../For the 00Z TAFS through 00Z Sunday evening/
Issued at 606 PM CDT Sat Jul 8 2017
VFR conditions will prevail through the period. While there may be
an isolated thunderstorms this evening, confidence is low in this
impacting any given terminal and have removed VCTS wording. The
next chance for thunderstorms is Sunday afternoon over southeast
Iowa, but have not mentioned at this time.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...FAB
LONG TERM...Podrazik
AVIATION...Ansorge
Area Forecast Discussion
National Weather Service Hastings NE
656 PM CDT Sat Jul 8 2017
.SHORT TERM...(This evening through Sunday)
Issued at 252 PM CDT Sat Jul 8 2017
The main concern in the short-term is the potential for
thunderstorms late this afternoon through the overnight.
An ill-defined cold front/sfc trough is situated roughly from
Lexington to O`Neil, NE. A weak perturbation aloft is also
visible as an area of drying on the mid-level water vapor channel.
Short-term models are in a bit better agreement that isolated to
scattered showers/storms should begin to develop in this vicinity
around 4PM, gradually shifting southward into the evening. The
most robust convection should be west of a line from Central City
to Red Cloud, where the RAP shows the highest corridor of
instability along with ~30 kts of bulk shear. While not overly
concerning from a severe weather perspective, there could be a few
strong to marginally severe storms.
Models quickly wrap up this activity by around 10PM, and most of
the forecast area will likely remain dry, especially south of
I-80. After midnight, a few additional showers or storms may
redevelop east of Highway 281, where an area of isentropic upglide
will persist through the overnight before gradually shifting to
the east of the area by early tomorrow morning.
Dry conditions should prevail through the day Sunday. The warmest
stretch we`ve seen so far this summer begins tomorrow. Highs will
reach the mid to upper 90s across most of central Nebraska and
will approach 100 degrees in north-central Kansas. Because of
relatively mild dewpoints (upper 50s to 60s), heat index values
will "only" be in the upper 90s to around 100 degrees though.
.LONG TERM...(Sunday night through Saturday)
Issued at 252 PM CDT Sat Jul 8 2017
We will have to watch for a stray thunderstorm or two moving out
of the Sandhills Sunday evening, but dry conditions are expected
to prevail for now.
The main story of the extended forecast is the impending heat
wave. It still appears that Monday through Wednesday will be the
warmest days, with highs in the upper 90s to low 100s for most of
the area. Like Sunday, the humidity won`t be overly oppressive,
so heat indices should max out in the low 100s each afternoon. We
also may get some relief in the way of breezy southwest winds on
Tuesday.
Precipitation chances continue to be nebulous and a little
difficult to pin-down as we transition to more zonal flow aloft.
Superblend brings us the best chances for precipitation Tuesday
night and again on Wednesday night. This seems reasonable given
that the GFS brings weak upper-level waves through the area during
these periods along with a favorable LLJ location. There are
still no particularly strong signals for much of severe threat
during the upcoming week, but given the time of year, we will
continue to watch this closely.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Sunday)
Issued at 650 PM CDT Sat Jul 8 2017
Could be some TSRA activity around in the first hour or so, but
support decreases rapidly. Bases should still be VFR, or mostly
so.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
SHORT TERM...Mangels
LONG TERM...Mangels
AVIATION...Heinlein
Area Forecast Discussion
National Weather Service Wilmington NC
1124 PM EDT Sat Jul 8 2017
.SYNOPSIS...
A weak cold front will stall across the area Sunday, enhancing
the risk for thunderstorms and excessive rainfall. The front
will slowly dissipate Monday and Tuesday as the Bermuda ridge
builds back across the Carolinas. The Bermuda ridge and Piedmont
trough will allow summertime heat and humidity to return,
peaking Wednesday through Friday. A cold front will approach
next Saturday.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 1130 PM Saturday...Except for the cell in Pender County,
NC, convective activity is weakening as it approaches the
coast. There is still quite a blast of west to northwest winds
as the massed outflow of the last few hours worth of storms
moves off the coast. Winds at both Myrtle Beach airports have
gusted to 30+ mph with this outflow, which should also moves
through the coastal Cape Fear area in the next 30-45 minutes.
This appears to be our only wave of storms tonight, and I have
sharply reduced PoPs behind this current activity as the
atmosphere is stabilized back to the west. Discussion from 1000
PM follows...
New storms have blossomed along I-95 from Florence northward
across Dillon and Lumberton within the past hour. The activity
south of Florence affecting Kingstree, Lake City, and the
Brittons Neck region of Marion County should continue to produce
the heaviest rainfall and the highest potential of severe
weather over the next couple of hours as it pushes eastward
toward the coast. Based on radar presentation, PoPs have been
increased again to 60 percent along the Cape Fear coast, and to
70-100 percent along South Carolina`s Grand Strand beaches.
Tonight`s severe weather risk will continue to be assisted by
dry air aloft: model analyzed DCAPE values of 1000-1200 J/kg
shows just how much negative buoyancy exists to strengthen
convective downdrafts and produce strong, potentially damaging
winds.
Both the 23Z and 00Z HRRR initialized poorly with convection and
were thrown out. It looks like the 18Z NAM (3 km) has the best
depiction of storms and has become our model of choice.
Discussion from 845 PM follows...
A pair of vorticity maxes aloft plus a synoptic cold front
moving into the area from the north will set the stage for a
stormy night across eastern North and South Carolina. After
another hot and humid day with temperatures in the 90s, the
atmosphere remains quite unstable with surface- based CAPE still
nearly around 2000 J/kg, and sufficient depth of moisture to
allow convectively unstable parcels to originate from anywhere
within a layer from the surface up through 6000 feet AGL.
I have increased PoPs to 80-100 percent in a zone out ahead of
the storms near Kingstree, SC as they move east-northeastward
toward Conway, eventually sagging southeastward to cover most
of Williamsburg, Georgetown, and Horry Counties through
midnight. Over an inch of rain is forecast across this area as
well, and I`ve added "heavy rain" to the forecast through
midnight. I`m also closely watching an area of storms dropping
southeastward through the NC Sandhills well out ahead of the
actual surface cold front. High chance PoPs have been maintained
here given what appears to be outflow possibly outrunning the
convection and stabilizing the atmosphere at least temporarily.
Storm organization should remain poor overnight as the main belt
of strong mid-level winds remains well to our north. Boundaries
will largely determine where storms track with virtually no
change anticipated in steering flow. The 21Z and 22Z HRRR runs
looked good, but the 23Z run did not initialize quite as well
with the South Carolina convection.
Little change has been made to overnight low temps, still
expected to fall to 73-75 inland, and 75-78 near the coast.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
As of 300 PM Saturday...The mid level pattern featuring troughing
over the Ohio Valley and ridging out west will remain in place
throuigh the short term period. If anything, the pattern weakens
by Tuesday morning. The trough is not deep enough to push a
cold front though the area and this front will dissipate slowly
through the period. This will provide a focus for intervals of
showers and thunderstorms. Some mid level drying may ease into
the northwest zones late in the period hence the slightly lower
pops in these areas at that time. Thermal profiles do show
slight cooling for daytime highs Monday and depending on cloud
cover some areas may struggle to reach the ninety degree mark.
Overnight lows remain steamy however in the middle 70s.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 300 PM Saturday...A surface cold front will have
dissipated across the area on Tue with the Bermuda ridge
building back across the Carolinas mid and late week as the
Piedmont trough sets up again. A cold front will approach the
area next Saturday. A typical summertime pattern will be in
place for much of the period. This means hit and miss showers
and thunderstorms each afternoon and eve. A lingering mid-level
trough Tue may help to enhance showers and thunderstorms. Then
POPS will be trending higher with the approach of a cold front
Sat and Sat night with several weak perturbations aloft helping
to increase the coverage and longevity of convection.
Highs will be warmest Wed through Fri, lower to mid 90s. Afternoon
and early eve heat index values during this time will approach
Heat Advisory criteria. Lows will be in the muggy 70s through
the period.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
As of 00Z...Anticipate a mixture of VFR/MVFR through into
Sunday afternoon with isolated periods of IFR as scattered
showers and thunderstorms, and intermittent low cigs, move
across the area ahead of an approaching cold front.
With the cold front draped across the western portions of the
Carolinas this evening, latest radar imagery depicts widespread
SHRA/TSRA activity just to the southwest and around to the
northwest, as a few showers are already moving into the forecast
area. Expect increasing SHRA/TSRA chances tonight inland as the
front moves closer, thus have carried VCTS at all terminals.
Anticipate a lull in the activity towards the morning hours,
with activity becoming widespread again as the frontal boundary
stalls near the area. As a result, expect VCSH/VCTS with periods
of MVFR/IFR to return and gusty variable winds on Sunday.
Heavier downpours may reduce visibility temporarily at times.
As for winds, gusty southwest winds may continue into the early
overnight hours, before decreasing, with sustained winds around
10 kts. Into Sunday, winds will become variable and gusty at
times.
Extended Outlook...MVFR/IFR conditions are possible from
thunderstorm activity, especially each afternoon and evening
thru Wednesday. Flight restrictions will become longer in
duration Sunday and Monday when thunderstorms are expected to be
most numerous.
&&
.MARINE...
NEAR TERM /THROUGH SUNDAY/...
As of 1130 PM Saturday...Showers and a few t-storms are moving
offshore, preceded by a blast of northwest winds gusting as high
as 25 knots. These offshore winds should veer back to the south
and southwest by 1-2 AM as the synoptic wind gradually
reestablishes itself. Discussion from 1000 PM follows...
Models show the cold front currently sinking southward through
the central Carolinas should stall before reaching the coast
late tonight. Two large areas of thunderstorms, one across the
NC Sandhills and another over the South Carolina Midlands, may
act in concert to push a pulse of westerly winds out across the
waters after midnight, but the actual front is expected to
remain inland. These thunderstorms should reach the coastal
waters later this evening with coverage ranging from 40 percent
near Surf City to 80 percent near Myrtle Beach.
Current observations show we are still experiencing winds near
20 knots from just east of the beaches all the way out to the
Frying Pan Shoals buoy offshore, and these conditions are
expected to persist until early Sunday morning. Seas are
currently 3-4 feet nearshore, and a solid 4 feet offshore with
some 5-footers possible near Frying Pan Shoals.
SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
As of 300 PM Saturday...No real surprises across the coastal waters
through the period. Winds will remain from the south/southwest at 10-
15 knots. There may be an observation or two just eclipsing 15 knots
overnight Sunday into Monday morning when the low level jet is
diurnally enhanced but these should be short lived. Significant seas
will remain 2-4 feet.
LONG TERM /TUESDAY THROUGH THURSDAY/...
As of 300 PM Saturday...A cold front will be dissipating upstream
of the waters Tue as the Bermuda High rebuilds across the waters.
The Bermuda High and Piedmont trough will act in unison to keep
wind speeds in the range of 10 to 15 kt for much of the period
and around 15 kt late Thu and Thu night. Seas will be mainly 2
to 3 ft, but building to a solid 3 ft later Thu and Thu night.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...RJD
AVIATION...SGL
Area Forecast Discussion
National Weather Service Jacksonville FL
745 PM EDT Sat Jul 8 2017
.UPDATE...Early this evening...radar still showing band of
scattered showers over Columbia and Gilchrist Counties...and
areas of light rain over our far nrn counties in s-ctrl
GA. Elsewhere precipitation has diminished. Have updated
hourly POP/weather grids. Latest HRRR runs keep suggesting
new convective development along boundaries after 00z...but
think environment will stabilize enough after 00z to prevent
anything more than isolated showers....covered by hourly 10
POPs.
Low temp forecast Tonight looks fine.
&&
.AVIATION...VFR next 24 hrs...except locally lower in
afternoon TSRA Sunday. Included VCTS in TAFs after 19z
Sunday for now. Next shift can look at 00z data to
assess need for TEMPO group for TSRA in subsequent TAF
issuances.
&&
.MARINE...High pressure over the central Atlantic will drift
northward over the next several days. A weak frontal boundary
will approach the southeast Georgia/northeast Florida waters
tonight and stall out across the area. This will keep increased
chances for thunderstorms through Monday. Onshore flow will
increase on Tuesday, with only isolated thunderstorms expected
for the rest of next week.
Rip Currents: Low risk Sunday.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 74 93 74 92 / 30 60 40 70
SSI 78 89 78 88 / 20 50 40 60
JAX 75 92 76 91 / 10 60 30 70
SGJ 75 88 76 89 / 10 50 30 40
GNV 74 91 73 92 / 20 60 30 60
OCF 73 89 73 92 / 20 60 30 50
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&
$$
Wolf/Kennedy/Corless
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
624 PM CDT Sat Jul 8 2017
.UPDATE...
Issued at 538 PM CDT Sat Jul 8 2017
The 18z MAV guidance came with 101 and 99 for highs at KVTN and
KLBF Sunday. This guidance has been 2 or 3 degrees too cool
lately. The deterministic 18z GFS has 104 and 102 for Sunday and a
new forecast is in place using the GFS which is close to the HRRR
EXP model.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 236 PM CDT Sat Jul 8 2017
A weak surface low centered between Ainsworth and Broken Bow
this afternoon will weaken this evening. Isolated to widely
scattered thunderstorms will be possible this evening in the
vicinity of the low, where weak surface convergence is noted along a
couple of surface boundaries. Otherwise a mostly clear sky is
expected with lows in the upper 50s and 60s.
Hot weather is expected Sunday to the west of surface trough which
will be located just east of the area. Mid to upper 90s are likely
at most locations, along with drier air as dew points fall into the
mid 40s to mid 50s as southwest winds advect drier air northeast
across the area. Have removed all pops for Sunday as really no focus
with surface trough to our east.
.LONG TERM...(Sunday night through Saturday)
Issued at 236 PM CDT Sat Jul 8 2017
Upper level high pressure centered across the southern Rockies, will
slowly drift north and be centered across the central Rockies by
weeks end. This keeps flow aloft mostly northwest through the
period. Gradually rising heights aloft through the week will keep
thunderstorm chances low, but not zero. Subtle waves within
northwest flow will have to be evaluated on a daily basis to see
where and when a few thunderstorms could develop. Otherwise very hot
week in store, with GFS ensemble indicating highs potentially around
100 give or take a few degrees through the entire upcoming week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 624 PM CDT Sat Jul 8 2017
VFR is generally expected all areas overnight through 22z Sunday.
A stray thunderstorm or two may form this evening. The area of
concern is a frontal boundary stretching from Stockville to
Brewster to Burwell. The boundary is expected to translate east
this evening with thunderstorm chances ending around 03z.
A dryline bulge shown in the NAM and HRRR EXP may spark a few
thunderstorms Sunday afternoon. The area of concern is generally
Along and east of a line from KBBW-KANW-KVTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...CDC
SHORT TERM...Taylor
LONG TERM...Taylor
AVIATION...CDC
Area Forecast Discussion
National Weather Service Miami FL
811 PM EDT Sat Jul 8 2017
.UPDATE...
Similar to yesterday evening, the convection continues to
diminish across the peninsula with the loss of diurnal heating.
Winds are expected to become light and variable overnight in the
interior with light southeast winds persisting along the east
coast. Short term model guidance generate a few showers with
possibly some embedded thunderstorms developing during the late
night over the Atlantic, then advect these storms towards the east
coast by early Sunday morning. These showers should diminish
quickly as they move inland. Thus, in the update, decreased PoPs
over the interior tonight. Otherwise, besides loading in the
latest short term wind guidance, all other variables appeared on
track.
&&
.PREV DISCUSSION... /issued 742 PM EDT Sat Jul 8 2017/
AVIATION...
VFR expected to prevail at all terminals tonight and through
Sunday morning, along with mainly light and variable winds.
Another round of afternoon thunderstorms may bring periods of MVFR
cigs/vis, especially over APF. Some outflow boundaries could
produce brief periods of strong and variable gusty winds.
PREV DISCUSSION... /issued 414 PM EDT Sat Jul 8 2017/
DISCUSSION...
Latest IR imagery from this afternoon shows broad
troughing over the Tennessee Valley and an elongated upper level
high pressure ridge over the Western Atlantic waters, near
Bermuda. The flow pattern into South Florida is from the south
southeast, with the region currently sandwiched between the
influence of the Bermuda high and a weak upper level low in the
eastern Gulf. The latter feature in the Gulf has allowed for 500
mb to lower slightly, down to around -7.0 C (which is average or
slightly below for this time of year). Similar to the last couple
of days, convection is concentrated over the interior and Gulf
coast. This activity continues to propagate in various directions,
based on colliding outflow boundaries. The strongest storms so
far today have produced wind gusts mainly in the 30 mph range
with brief heavy rain and frequent lightning. Short term models,
such as the HRRR and Hi-Res WRF, prog this activity to maintain
over the peninsula, including portions of the east coast metro,
through early this evening, then diminish with the loss of diurnal
heating. Wind will become light and variable over the interior
tonight with southeast winds 5 to 10 mph persisting along the east
coast metro region. Showers with an occasional embedded
thunderstorm may develop once again over the Atlantic waters and
drift towards the eastern portion of the peninsula by early Sunday
morning.
Sunday through mid next week: Little changes synoptically on
Sunday, leading to a very similar weather pattern as today. Expect
light southeasterly flow with both the east and west coast sea
breezes developing. Thunderstorms generated off of this boundary
will propagate in random directions, based on the local effects of
the outflow boundaries and their collisions. The main threat
threat with the storms will again be frequent lightning, brief
heavy rain, and gusty/erratic winds. GFS forecast PWATs drop to
between 1.50"-1.75", so this may translate to slightly less
afternoon convection. With high pressure dominating near Bermuda
from early to mid week, rounds of increased moisture will
advect over the peninsula from the southeast through the period.
The arrival of deeper atmospheric moisture may lead to increase of
shower/storm coverage by Wednesday/Thursday. Maximum temperatures
through the period will remain around 90 degrees with low
temperatures in the mid 70s in the interior to near 80 along the
east coast metro. These values near normal for this time of year.
MARINE...
Prevailing east-southeast winds around 10 knots
will continue across the South Florida waters through Sunday
as high pressure remains to the north of the region. Both the
Gulf and Atlantic seabreezes are expected to develop each
afternoon, leading to locally higher winds near the coast.
Isolated to scattered showers and thunderstorms are possible each
day, with locally higher winds and seas as well as lightning
near any thunderstorms.
AVIATION...
The next few hours will be dominated by weak synoptic flow, and
shifting wind directions due to thunderstorm outflow boundaries.
Thunderstorms are expected to migrate inland and away from east
coast terminals by 20Z. APF could see some storms during the
afternoon. Terminals should remain VFR but brief MVFR is possible
during any strong thunderstorms. Storms and winds calm down for
the overnight hours. A similar pattern is expected for tomorrow in
terms of shower/thunderstorm timing for east coast terminals.
&&
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 77 91 79 90 / 30 30 30 40
Fort Lauderdale 79 89 80 89 / 30 30 40 40
Miami 78 90 79 90 / 30 30 50 40
Naples 75 90 76 92 / 20 50 30 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
GM...None.
&&
DISCUSSION...27/JT
MARINE...27/JT
AVIATION...17/AR
Area Forecast Discussion
National Weather Service Norman OK
1052 PM CDT Sat Jul 8 2017
.UPDATE...
Adjusted precipitation chances and temperatures.
&&
.DISCUSSION...
Increased and added precip chances to portions of western north
Texas to account for the ongoing, yet weakening, convection
persisting across Texoma. Removed chances after 2 AM CST from
Oklahoma and Texas as overall conditions continue to be
unfavorable for development. Looking up stream, in western
Kansas, not much in the way of convective activity. Instability
will continue to wane through the overnight and with a lack of
forcing, not expecting much in the way of precipitation. The
latest HRRR has bought into this trend, backing way off on
development, the RAP, to a lesser extent, concurs. Really, based
off going conditions and trends, feel confident to drop
categorical precipitation chances for the early morning hours
across the region.
Kurtz
&&
.PREV DISCUSSION... /issued 1026 PM CDT Sat Jul 8 2017/
DISCUSSION...
AVIATION...
Scattered rain and thunderstorms over the southern third of
Oklahoma will dissipate before sunrise. South winds and VFR
conditions are expected apart from thunderstorms.
PREV DISCUSSION... /issued 648 PM CDT Sat Jul 8 2017/
DISCUSSION...
AVIATION...
Scattered rain and thunderstorms over the southern half of
Oklahoma will dissipate before midnight. South winds and VFR
conditions are expected apart from thunderstorms.
PREV DISCUSSION... /issued 240 PM CDT Sat Jul 8 2017/
DISCUSSION...
A MCV continues to produce elevated showers NW of OKC this
afternoon. Looking at visible imagery and surface observations,
it appears this feature will interact with a remnant boundary near
the I40 corridor through early this evening. A few of the storms
could become severe before sunset (mainly wind threat) near and
south of OKC where heating hasn`t been as inhibited by
cirrostratus. Most of this activity should wane as it moves SE
after dark. Additional chances will return late tonight through
early Sunday morning, mainly over southern OK, as a weak mid level
shortwave trough progresses southward. Isolated, diurnal
development will then be possible along and south of I40 during
the afternoon and evening Sunday.
Rain chances will likely drop significantly by Mon as heights
increase with an expanding upper ridge from the west. A few
showers and storms may be possible on its southern/SE periphery
Tue as a mid to upper trough slides westward over central TX.
Otherwise, expect a drying trend with regards to precip through
most of the week as the upper ridge expands over the central
CONUS.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 70 94 73 96 / 20 20 10 10
Hobart OK 72 98 74 97 / 10 20 10 0
Wichita Falls TX 74 98 74 97 / 40 20 20 10
Gage OK 68 98 72 100 / 10 10 10 0
Ponca City OK 71 95 73 95 / 10 10 10 0
Durant OK 72 91 73 94 / 30 30 20 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&
$$
04/09
Area Forecast Discussion
National Weather Service Pueblo CO
313 PM MDT Sat Jul 8 2017
.SHORT TERM...(This evening through Sunday)
Issued at 313 PM MDT Sat Jul 8 2017
Isolated to scattered -tsra have developed over the mountains at mid-
afternoon, with a few storms moving out across El Paso county as
well. While instability looks plentiful (CAPEs 1000-1500 J/KG),
shear is rather weak (0-6km 20-30 kts), suggesting most storms will
stay sub-severe into the evening. Latest HRRR is considerably more
aggressive building storms eastward across the plains this evening,
as convective outflows may serve to consolidate convection east of I-
25. Will boost pops over the plains to account for this possibility,
with most storms then ending in the 03z-06z time frame. On Sun,
pocket of drier air will rotate southward across CO, leading to a
downturn in convection, especially over the I-25 corridor and on the
plains. Mountains will see isolated to scattered storms once again,
though drier low levels suggest precip amounts will be rather light
most areas. Max temps will begin to climb as mid level temps rise,
leading to mid/upper 90s reappearing on the plains by late
afternoon.
.LONG TERM...(Sunday night through Saturday)
Issued at 313 PM MDT Sat Jul 8 2017
Extended models are in fairly good agreement on keeping high
pressure in some form across the region through the long term, with
mainly diurnal convection in play. Expect scattered to likely
convection over the higher terrain each aftn and eve, and isolated
to low-end scattered pops across the eastern plains.
Sunday night through Tuesday...A relatively flat ridge of high
pressure will remain across the region, stretching from the Great
Basin to the central US plains. Both Mon and Tue will be very hot
days, the hottest of the extended period, with max temps in the mid
to upper 80s for the high valleys, and 90s to around 100F for the
eastern plains. Any storms that form over the mts during the aftn
hours will likely be slow to move, and area burn scars will need to
be monitored for heavier rainfall amounts.
Wednesday through Saturday...Models agree on the upper ridge
amplifying once again and edging to the west, though the GFS is much
farther west with the location of the ridge axis. The GFS places the
ridge axis along the UT/CO state line, while the EC places the axis
over CO. Continued diurnal convection is expected, though the storms
will probably move a bit faster off of the higher terrain once they
form. Temps will remain hot, though with about 5 degrees of cooling
should be more seasonal in nature. Look for max temps in the 80s for
the high valleys, and mid 80s to mid 90s for the eastern plains.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 313 PM MDT Sat Jul 8 2017
Scattered tsra will persist into this evening across the area, and
will continue with vcts at all taf sites until 02z-03z. With
increased moisture, cloud bases and vis with any storms will likely
be lower than yesterday, with brief MVFR or even IFR under the
strongest storms. Storms then end 03z-06z, with clearing skies and
VFR conditions overnight and through the first half of Sun. Isolated
-tsra will develop over the mountains 17z-18z Mon, though drier
air moving south through state will keep storms weak and tied
mainly to higher terrain through the afternoon.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...MOORE
AVIATION...PETERSEN
Area Forecast Discussion
National Weather Service Las Vegas NV
648 PM PDT Sat Jul 8 2017
.SYNOPSIS...The first significant push of monsoon moisture is
expected to bring expanding thunderstorm chances to the area over
the next few days. With the increasing moisture and cloud debris,
daytime temperatures for Sunday and Monday are expected to be cooler
before most of the area gradually warms up and drys out Tuesday
onward.
&&
.UPDATE...Scattered thunderstorms extending from Dolan Springs to
south of Wikieup are slowly moving to west and are expected to move
over the Colorado River Valley over the next couple of hours. The
latest HRRR supports tstorm activity from this line moving to
eastern San Bernardino County before diminishing. Expanded
thunderstorm chances further west to account for this. -Salmen
&&
PREVIOUS DISCUSSION...253 PM PDT...
.SHORT TERM...through Monday night.
Thunderstorm activity will be on the increase through Monday as
monsoon moisture pushes into the area from Arizona. Precipitable
water values greater than an inch currently encompass much of the SE
CWA and are forecast to expand to much of the southern half of the
area on Sunday and Monday. A juicer airmass is on our southern
doorstep with surface dewpoint temperatures in the 50-60 degree
range. A large thunderstorm complex over south central Arizona this
afternoon is moving westward with the general 850-700MB flow
directing it towards our area. The latest HRRR surface wind
analysis and forecast suggests outflow winds from this activity as
well as other convection over central Arizona reaching the eastern
Mohave County border late this afternoon and spreading west into
Clark County this evening. In addition, the HRRR brings thunderstorm
outflow winds to Lincoln and Clark counties from storm activity over
southwestern Utah which could bring storm activity to the Las Vegas
Valley later this evening. All and all, it should be interesting to
see how this all plays out.
.LONG TERM...Tuesday through Saturday.
Upper high shifts further east into the central states Tuesday-
Thursday allowing southwest flow associated with Pacific Northwest
trough to bring a drier/more stable air mass to parts of the region.
The probability of thunderstorms decrease Tuesday-Thursday across
San Bernardino County and southern Nevada, more so across Mohave
County Wednesday and Thursday. The troughing influence will allow
for a slight chances of thunderstorms across northern portions of
Inyo and Esmeralda Counties. The models show the high center
shifting west becoming established once again over northern Utah
Friday/Saturday. Easterly flow south of the high center combined
with an inverted trough over northwest Mexico should have low level
moisture pushing back west into Mohave County by next weekend. Near
to slightly above normal temperatures early-midweek will begin to
rise late week. Tropical Storm Eugene in the eastern Pacific is
forecast to become a Hurricane Sunday. Then Hurricane Eugene will
move northwest well away from the Baja Peninsula through Monday
before dissipating in colder waters by Wednesday. None of the models
at this time show any injection of moisture into the region from
Eugene but its something we`ll be monitoring closely. Temperatures
will be around normal Tuesday through Thursday, but will once again
warm to around 5-7 degrees above normal by Friday as the high
rebuilds back to the west.
&&
.AVIATION...For McCarran...Gusty outflow winds will impact the
airport early this evening. South winds around 20-30 kts are likely
with the initial outflow boundary late this afternoon, but its
possible that a second outflow boundary from Arizona will impact the
terminal early this evening. Models are indicating the potential for
southeast winds 20-30 kts occurring between 01-03z this evening. If
they occur they would likely last through 04-05z before shifting
back to the southwest with speeds around 10 kts overnight.
Thunderstorms are likely to be more scattered Sunday with gusty and
erratic outflow winds impacting the terminal at times during the
afternoon and early evening. No operationally significant ceilings
are forecast, but localized turbulence and icing hazards can be
expected with any shower/thunderstorm activity.
For the rest of southern Nevada, northwest Arizona and southeast
California...Generally light winds following typical summertime
diurnal trends expected at most terminals once again, outside of
thunderstorm influences. Thunderstorms are possible once late this
afternoon and evening, mainly focused on higher terrain, with low
chances of impacting the terminals. Gustier winds are possible by
the evening, especially east of a DAG-LAS-CDC line where
consolidated thunderstorm outflow looks likely. Isolated to
scattered thunderstorms are forecast Sunday with slightly better
coverage. Gusty outflow winds will be the main impact, but brief
heavy rain will be possible.
&&
.FIRE WEATHER...Monsoon moisture will bring an increase in
lightning activity to the area over the next few days with the
initial round of storm activity possibly dropping very little rain
resulting in an increasing potential for new fire starts. As
moisture increases and deepens, there will be better chances for
wetting rains from thunderstorms. A drying and warming trend will
commence by Tuesday through the end of the week.
&&
.HYDROLOGY...Isolated thunderstorms over the eastern Sierra over
the next few days may aid snowmelt runoff and keep some drainages
elevated with ongoing minor flooding possible. 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...Increasing monsoonal moisture
will lead to increasing thunderstorm chances and cooler temperatures
Sunday and Monday. Conditions are not currently forecast to be
favorable for widespread flash flooding risks, however, spotters are
always encouraged to report significant rainfall amounts as well as
any reports of damage or flooding.
&&
$$
Short Term...Salmen
Long Term/Aviation...Gorelow
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