Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/13/19
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
813 PM CDT Fri Jul 12 2019
.UPDATE...
Issued at 809 PM CDT Fri Jul 12 2019
Not planning on any major changes this evening. Convection over
southwest North Dakota has had a hard time maintaining itself, and
with only slight LLJ overnight, it may continue to struggle. Other
convection over nw North Dakota looks a bit more organized and
could clip the northern CWA late tonight. Based on this and the
latest HRRR output, will keep slight chc/chc pops across much of
the forecast area overnight. Temperatures look fine for now.
&&
.SHORT TERM...(This Evening through Saturday Night)
Issued at 337 PM CDT Fri Jul 12 2019
Low confidence forecast with regards to precipitation chances.
As of 20Z, a frontal boundary is over southeast SD and across
western Nebraska. Weak shortwave over southeast Wyoming should cause
convection over western Nebraska this afternoon. Storms could become
a convective complex as they track east tonight, possibly clipping
south-central South Dakota. Additional thunderstorm activity is on
going over eastern MT and western MN. Shortwave energy is showing up
well on water vapor this afternoon. More widespread convection will
develop after 0Z tonight over eastern MT. With an east-southeast
upper level steeping flow, these storms should eventual track across
this CWA after 6Z. A few storms may become strong with wind and
hail possible. Saturday appears dry with highs reaching the upper
80s and low 90s.
Models are showing a possible MCS Saturday night into Sunday morning
somewhere in the Northern Plains. Increasing 700 mb temps could cap
this CWA, with the convection passing across North Dakota. A couple
models show a weaker EML with convection tracking through the
CWA. With low confidence, will broad bush the CWA with low pops
Saturday night.
.LONG TERM...(Sunday through Friday)
Issued at 337 PM CDT Fri Jul 12 2019
The Sunday through Friday period looks to have above normal
temperatures with periodic short waves bringing several mesoscale
convective systems to the region. Upper level troughing along the
Pacific Northwest coast with broad upper level ridging over the
central U.S. will start the period. Short waves from the western
trough will be bringing off and on chances of showers/storms. The
best chances of showers/storms looks to be Tuesday afternoon into
Wednesday as the western trough ejects out and across our region
along with a surface cold front. This will flatten out the upper
ridge some before it pops back up Thursday and Friday as stronger
upper level troughing develops again over the Pacific Northwest.
This will again send more short waves over our region. It will
certainly feel like mid-July from Sunday through Friday with highs
in the upper 80s to the mid 90s along with dewpoints in the mid 60s
to the lower 70s/humid conditions along with abundant sunshine.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 636 PM CDT Fri Jul 12 2019
VFR skies/vsbys are expected through the valid taf period at all
terminals. Isolated storms are possible overnight.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...TDK
SHORT TERM...SD
LONG TERM...Mohr
AVIATION...TDK
Area Forecast Discussion
National Weather Service Boston/Norton MA
1048 PM EDT Fri Jul 12 2019
.SYNOPSIS...
High pressure from the Great Lakes to the Mid Atlantic region
will provide dry but very warm and humid weather here Saturday
but trending less humid Sunday. As the area of high pressure
approaches Monday and then crest over the area Tuesday expect
more dry and very warm conditions. But mid week the high moves
offshore with summer heat and humidity building.
&&
.NEAR TERM /THROUGH SATURDAY/...
1045 PM update...
Convection continued to diminish this evening. Last few runs of
the HRRR and its time-lagged ensemble had the best handle on
this. Expecting mostly rain-free weather after midnight. Minor
tweaks to temperatures to bring them back in line with observed
trends.
Previous Discussion...
Mid level trough over NY state and associated wind shift
line/frontal boundary across central MA into eastern CT is
triggering scattered convection over eastern MA into RI and
southeast CT. Drier air aloft approaching from the west is limiting
convection to eastern CT/MA and RI. This drier mid level air has
resulted in cores struggling to reach the -10C isotherm and if this
occurs storms then begin entraining drier air and updraft weakens.
However convergence from seabreeze boundaries and advection of
higher dew pt air may be able to overcome this a bit across
southeast MA, where strongest convection is expected. Although not
expecting severe storms given weak deep layer shear, poor mid level
lapse rates and deepening mid level dry air. Main issue will be
brief heavy downpours but not nearly the magnitude of what we saw
this morning over Plymouth county.
Otherwise trough passage/wind shift will usher in slightly
drier/less humid air with dew pts falling from the low 70s to the
low 60s. Patchy fog and lows clouds possible later tonight
especially across eastern MA. Warm with lows in the 60s. Humid with
dew pts in the 60s but not as muggy as last night.
&&
.SHORT TERM /SATURDAY NIGHT/...
Update 410 pm
Saturday...
Short wave ridging over the region tomorrow as mid level trough from
night moves east and upstream trough over Great Lakes/Ontario still
well to the northwest. Thus dry weather across southern New England
with typical mid July heat and humidity as highs climb to 85-90 and
dew pts in the 60s.
Saturday night...
Mid level trough moves across northern New England with its surface
cold front moving thru southern New England late. Given lack of deep
layer moisture and instability expecting a dry frontal passage.
Arrival of less humid airmass waits until Sunday when mid level
trough moves east of our longitude. With dew pts still in the 60s
and light winds may see some patchy fog.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Highlights...
* Warm and dry Sun/Mon with relatively low humidity
* Heat and humidity build Tue/Wed
* Increasing risk of showers/t-storms Wed/Thu
* Wetter late week...potential for remnants of Barry
Sunday and Monday...
Saturday night`s cold front will be on the way out of the region by
mid morning Sunday ushering in a much drier air mass with quickly
clearing skies as dewpoints drop from the mid 60s into the mid 50s.
This will make for a pleasant, less humid day to end the weekend as
high pressure builds in. 850 mb cold pool shifts overhead dropping
temps a few degrees (+14C) on Sunday and even cooler (+11C) on
Monday. This will support highs in the 80s each day, but Monday will
be the cooler of the two.
Tuesday through Thursday...
Zonal flow behind the trough gives way to rising heights and a
building ridge of high pressure as we go into mid week. Polar jet
moves north allowing heat and humidity to increase steadily. Flow becomes
southwest increasing moisture advection with dewpoints in the
60s by Tuesday and 70s by Wednesday and Thursday. 850
temperatures jump to +17 to 20C supporting very warm
temperatures at the surface, near 90 on Tuesday and reaching
into the mid 90s Wednesday. The heat and humidity will make for
increasingly uncomfortable conditions. With increased heat and
humidity comes increased instability and the return of
rain/thunderstorm chances Wednesday and Thursday as a few
shortwaves pass through.
Friday...
Increased uncertainty in the forecast late week as a more
potent shortwave approaches from the Midwest, potentially
interacting with the remnants of Barry. Details are still unclear
but trending toward a wetter forecast to end the work week.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Short Term /through Saturday Night/...High confidence.
Tonight...
A few remaining showers over eastern MA dissipate late this
evening. VFR prevails, except over portions of eastern MA where
low clouds/fog may develop overnight to MVFR or briefly IFR
possible.
Saturday...
Any low morning clouds and/or fog over eastern MA
quickly erodes and gives way to VFR. Dry weather prevails with
local seabreezes possible.
Saturday night...
VFR and dry weather.
KBOS Terminal...VFR but MVFR at times in scattered showers with
possible isolated thunder 20z-00z, then dissipating thereafter.
KBDL Terminal...High confidence in TAF.
Outlook /Sunday through Wednesday/...Moderate
Saturday Night through Tuesday Night: VFR.
Wednesday: Mainly VFR, with areas MVFR possible. Chance SHRA,
isolated TSRA.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Short Term /through Saturday Night/...High confidence.
Tonight...
Scattered showers dissipating. Light winds with fog developing
overnight.
Saturday and Saturday night...
High pressure from the Great lakes to the Mid Atlc region
provides dry weather, good vsbys and light winds.
Outlook /Sunday through Wednesday/...Moderate confidence.
Sunday through Tuesday: Winds less than 25 kt.
Tuesday Night: Winds less than 25 kt. Areas of seas approaching
5 ft. Slight chance of rain showers, isolated thunderstorms.
Wednesday: Winds less than 25 kt. Seas locally approaching
5 ft. Chance of rain showers, isolated thunderstorms.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.
&&
$$
SYNOPSIS...Nocera/BW
NEAR TERM...Belk/Nocera
SHORT TERM...Nocera
LONG TERM...BW
AVIATION...Nocera/BW
MARINE...Nocera/BW
Area Forecast Discussion
National Weather Service Duluth MN
617 PM CDT Fri Jul 12 2019
.UPDATE...
Issued at 616 PM CDT Fri Jul 12 2019
Updated for the 00Z aviation discussion. Will be updating shortly
for the latest radar trends as well.
&&
.SHORT TERM...(This evening through Saturday night)
Issued at 324 PM CDT Fri Jul 12 2019
Isolated thunderstorms this afternoon, some of which may be
strong, are the main concern for the short term forecast.
A cool front stretched from Isle Royale to northern Iron County
to Birchwood in Sawyer County to northwest Iowa this afternoon.
Temperatures have climbed into the low 80s with dewpoints in the
upper 60s to near 70 degrees ahead of the front. Drier air was
found north of the front and temperatures were in the upper 70s to
upper 80s. The airmass ahead of the front was moderately unstable
with 1000-1500 J/kg with 0-8 km bulk shear values of 45 to 50
knots. There is enough instability and shear for strong storms,
should storms develop. The boundary layer is relatively deep,
around 4 kft per the RAP soundings in the area and the front seems
to be shallow and may not have sufficient forcing to overcome the
deep mixed layer. Theres still a potential for a few storms
over northwest Wisconsin, but the chances seem to be dwindling
quickly.
High pressure will be the main influence from tonight through
Saturday with a period of quiet and dry weather expected.
Temperatures will be similar to today with highs in the low and
middle 70s along the north shore to the middle 80s in central
Minnesota and northwest Wisconsin. A few storms will threaten the
International Falls area Saturday night, but confidence in storm
development isnt especially high. Included low-end chance POPs
to account for the low confidence.
.LONG TERM...(Sunday through Friday)
Issued at 324 PM CDT Fri Jul 12 2019
A hot, humid, and active weather pattern going into mid-July.
On the synoptic scale a broad mid/upper level ridge will be over the
Great Plains over the weekend, moving east towards the Upper Midwest
late in the weekend. A resultant area of high pressure will be over
the Upper Great Lakes on Sunday with south/southwesterly flow at low
levels advecting in warmer air and rich low level moisture. Dew
points will approaching the low 70s on Monday, downright oppressive
humidity, with highs in the 80s to near 90 in some spots and heat
index values in the upper 90s. A mid-level shortwave trough moving
across southern Canada will bring a weak cold front to the area on
Tuesday leading to some relief from the heat and humidity, but then
another mid-level ridge builds in from the west and the pattern
repeats by late week. The coolest day will likely be Wednesday with
highs in the upper 70s to low 80s and dew points in the mid 50s to
mid 60s.
A chance for storms every day through the long term forecast with
typical differences across model guidance. There is a potential for
strong to severe storms Sunday and Monday, but it is difficult to
determine how upstream convection will evolve and thus hard to say
exactly where/when the greatest threat for severe storms will occur.
There may be a potential for severe storms through the rest of the
week, but predictability for how the convection will evolve each day
is too low to get much more specific than that.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 616 PM CDT Fri Jul 12 2019
Weak cold front sliding through the area as of issuance time has
generated a few thunderstorms over NW Wisconsin, but these have
avoided KHYR so far and have left them out of the terminal
forecast for that site. Otherwise, the sites are VFR. between 09z
and 12z there may be some MVFR fog that affects the terminals, and
have included it for KHIB, KINL, KBRD and KHYR, through KDLH may
need it as well. Once this fog burns off, expect VFR conditions
with light northwest winds becoming west by the end of the TAF
period.
&&
.MARINE...
Issued at 324 PM CDT Fri Jul 12 2019
No hazardous marine conditions for the next 48 hours. Northwest
winds 5 to 10 knots tonight then southwest winds around 5 knots or
less on Saturday. A low chance for a storm late afternoon today then
clearing out tonight and sunny Saturday and clear Sat night. An
active weather pattern begins Sunday with chances for thunderstorms
every day through the week.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 58 81 60 85 / 0 0 0 40
INL 52 82 62 85 / 0 0 30 40
BRD 60 85 65 88 / 0 0 10 30
HYR 58 83 60 88 / 40 0 0 20
ASX 59 80 60 88 / 10 0 0 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&
$$
UPDATE...LE
SHORT TERM...Huyck
LONG TERM...JJM
AVIATION...LE
MARINE...JJM
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
931 PM CDT Fri Jul 12 2019
.UPDATE...
Scattered showers and a few thunderstorms across the Rio Grande
Plains earlier in the evening have all dissipated, but not before
producing multiple outflow boundaries. Some of this cool air from
these storms has dropped temperatures at some locations into the low
80s or even the upper 70s already. Hondo is currently sitting at 79
and Boerne at 77 at this hour. Because of this temperatures have been
retrended to account for these pockets of cooler temps. Other than
temps, the rest of the forecast is on track for the overnight period.
Based on early indications from the 00z models and looking back at
the 12z SPC HREF models a 20% (Slight Chance) PoP has been added
across much of the area east of I-35 for tomorrow afternoon.
Satellite trends with Tropical Storm Barry continue to show
convection spreading farther westward. A band of showers and storms
is already currently moving west along the Texas/Louisiana border.
Based on these trends, increased moisture due to the storm
(Precipitable Water values increase from around 1.75 inches this
evening to near 2.0 inches by late tomorrow), and the fact that based
on forecast soundings we should meet on convective temperatures
tomorrow isolated showers and storms are possible during the
afternoon hours. Otherwise no changes were made to the forecast with
Barry still forecast to make landfall along the Central Louisiana
coast producing only a few isolated showers and storms here tomorrow
afternoon through Sunday.
&&
.PREV DISCUSSION... /ISSUED 636 PM CDT Fri Jul 12 2019/
AVIATION /00Z TAFs/...
VFR conditions are expected to prevail through the TAF period.
Northeast to north winds 5-10 knots at the Interstate 35 terminals
will continue through Saturday afternoon and evening with Tropical
Storm Barry to the east of the region, with an east to northeast flow
expected at DRT. As deeper tropical moisture associated with Barry
lifts into the eastern counties Saturday afternoon, convective
temperatures in the lower 90s near AUS should promote the development
of a few SHRA near the terminal. Any SHRA that develop are expected
to quickly dissipate after sunset Saturday.
PREV DISCUSSION... /ISSUED 307 PM CDT Fri Jul 12 2019/
SHORT TERM (Tonight through Saturday Night)...
Afternoon satellite and radar data show some isolated convection
ongoing across portions of the southern Edwards Plateau, including
Val Verde and Edwards counties. We are also seeing a developing cu
field across portions of the western Hill Country and along the Rio
Grande in the visible satellite loop. Given these trends and
continued support from the HRRR model, we have added a low chance
for isolated showers and storms to the forecast for the remainder of
this afternoon over the western Hill Country. The cu field does
extend farther south into the I-35 corridor, but is showing signs of
dissipation with southward movement.
Otherwise, hot temperatures are in place with late afternoon
temperatures in the 90s along with dewpoints in the mid 60s to lower
70s. So far, low-level moisture is not mixing out as efficiently as
yesterday and this is helping to boost heat index values to near 105
degrees for areas along and east of I-35. It does not appear we will
reach heat advisory levels today, so will hold off on any headlines
at the present time.
Afternoon convection will weaken with the loss of daytime heating and
we will go with a dry forecast for the overnight hours. We should see
a little more cirrus clouds tonight, as upper level outflow from
"Barry" propagates westward. Overnight lows will remain in the 70s
for most areas, except for a few readings in the upper 60s in the
Hill Country.
LONG TERM (Sunday through Friday)...
We should see enough moisture across the coastal plains and Highway
77 corridor on Sunday to yield some isolated to scattered convection,
especially during the peak heating afternoon hours. Temperatures are
also expected to remain above normal with highs in the lower 90s to
near 100 along with lows in the 70s. For Monday, any influence from
"Barry" will remain east of our region as surface winds begin to
trend back to a more southerly direction. Southerly winds in the low-
levels will remain intact through most of the upcoming work week.
This along with high pressure aloft over the southern plains states
will lead to hot and humid weather.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 98 73 97 76 96 / 10 - 10 10 20
Austin Bergstrom Intl Airport 95 73 96 77 96 / 10 - 10 10 20
New Braunfels Muni Airport 99 72 97 77 97 / 10 - 10 10 20
Burnet Muni Airport 92 70 94 74 94 / 20 - 10 - 10
Del Rio Intl Airport 100 76 100 75 100 / 20 10 - 0 0
Georgetown Muni Airport 93 73 96 75 95 / 10 - 10 10 10
Hondo Muni Airport 95 72 99 76 98 / 10 10 - 0 20
San Marcos Muni Airport 96 72 97 77 97 / 10 - 10 10 20
La Grange - Fayette Regional 95 75 96 77 96 / 10 - 20 20 20
San Antonio Intl Airport 95 74 97 77 97 / 10 - 10 - 20
Stinson Muni Airport 97 75 97 78 98 / 10 - 10 - 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Aviation...Huffman
Short-Term/Long-Term...Treadway
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1041 PM EDT Fri Jul 12 2019
.SYNOPSIS...
A weak stationary front over western North Carolina may drift north
this weekend as the tropical system makes landfall then moves north
across the lower Mississippi Valley. Tropical moisture will spread
east along the stalled front. Unsettled weather will
likely continue through much of next week as a moist air mass
persists over the southeast and the remnants of Barry move from the
Mississippi River Valley through the Ohio Valley and into the
central Appalachians.
&&
.NEAR TERM /THROUGH SATURDAY/...
As of 1035 PM: Mostly quiet out there except for a couple
isolated cells over the Escarpment and in the southern
Lakelands. Mesoanalysis indicates upwards of 2000 J/kg of MUCAPE
remaining across the southern half of the area, so any lingering
boundaries from earlier outflows could continue to spawn isolated
cells well into the night. Indeed some new cells just kicked off in
NE Georgia near Gainesville, and this likely will propagate into
our GA counties soon. Latest HRRR and 3km NAM output support a
reduction in PoPs such that our fcst eventually goes below slight
chance everywhere in the early morning once the instability is
exhausted. Other than that, mountain valley fog continues to be
the primary concern for the late night into morning hours. Some
fog and/or low stratus could set up locally following any overnight
precip too.
Expect numerous coverage of showers and thunderstorms to develop
again on Saturday, likely with earlier than normal initiation. The
air mass remains very moist and very unstable. Shear remains minimal
with very high dCAPE developing again. Isolated wet microbursts
will be possible. The weak boundary over the area may shift slightly
south, bringing the axis of highest PoP a little south of the NC/SC
border. Coverage may even remain just in the scattered range over
the northern tier of the CWFA. PW values will remain high as well.
Isolated flooding also remains possible where cells merge or
training sets up. Highs will be near normal and slightly above
normal where lower precip chances exist.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 215 pm Friday: Various factors, including some indirect
impacts associated with Tropical Cyclone Barry, which will be
drifting north through the lower Miss Valley through the period, are
expected to limit convective activity across the western Carolinas
and northeast GA early in the new week. In the interim, diurnal
convection lingering from Saturday afternoon should steadily
diminish during the evening.
For Sunday, extensive mid/high level cloud cover associated with
Barry is expected to brush the western part of the forecast area,
which is one factor that will inhibit afternoon destabilization.
Additionally, upper ridging along with some mid-level warm advection
along the outer periphery of the cyclone will act to suppress
upward vertical motion while also further limiting instability.
Meanwhile, introduction of slightly lower theta-e air over the NC
Piedmont along with stable layer depicted in forecast soundings is
expected to result in very high LFCs across this area Sunday
afternoon and evening. As such, pops are limited to 20-30% across
the western half of the area, and only 10-20% across much of the
eastern portion. A sight uptick in the diurnal convective potential
is expected for Monday, as the upper ridge axis shifts slightly
north and east of the forecast area. Max temps will be near-to-below
normal through the period while min temps will remain a couple of
degrees above climo.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 2 pm EDT Friday: Starting 00Z Tuesday remnant tropical low
located near Memphis while following the Mississippi River. The
remains of Barry will turn NE during mid week and move across the
Ohio River. The broad circulation around this system will result in
upslope low level flow for our mountains resulting in periods of
heavy rainfall. The upslope flow will be on south and southeast
facing slopes Monday night into Tuesday night then transition into a
component from the NW effecting the Tennessee border counties with
the system approaching the Atlantic coast. At the end of the week,
the mid nation ridge builds centered roughly over Arkansas. It
is interesting that the GFS takes the remains of Barry around the
eastern periphery of the ridge and brings it west to Alabama by the
end of the weekend. The ECMWF dips the low through the trough axis
next weekend and carries it out to sea. Confidence has been higher
in the EC. Max Temps near normal and Min Temps slightly above normal.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: Diurnal convection has waned a bit earlier
than the previous few days, though there is abundant elevated
CAPE remaining over much of the area, particularly the southern
Upstate, so the chance of a rogue SHRA or even TS popping up
does exist. Only at KCLT was this threat worth mentioning, due
to its proximity to recent activity. Cirrus debris will be seen
into the early overnight hours; near an axis of heavy rain this
afternoon that extends just south of KCLT, enough of this should
clear to allow some radiation and formation of IFR. Hence TEMPO
at KCLT. And like recent mornings, some patchy low VFR stratus is
likely to form elsewhere in the Piedmont despite not being indicated
by the 00z TAF cycle guidance. In the mountain valleys, though,
expect IFR cigs with some fog. The synoptic scale setup changes
little for Saturday afternoon with a weak stalled frontal zone and
favorable lapse rates aloft suggesting good destabilization. Chances
of SHRA/TSRA are moderately likely at all sites except KHKY,
warranting prevailing mention.
Outlook: More typical, scattered convective coverage expected into
the middle of next week. Patchy fog and low cigs remain possible
during the morning hours.
Confidence Table...
02-08Z 08-14Z 14-20Z 20-00Z
KCLT High 100% High 100% High 100% High 100%
KGSP High 100% High 100% High 100% High 100%
KAVL High 95% Low 54% Med 68% High 100%
KHKY High 100% High 88% High 100% High 88%
KGMU High 100% High 100% High 100% High 100%
KAND High 100% Med 67% High 100% High 100%
The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:
www.weather.gov/gsp/aviation
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...DEO
NEAR TERM...RWH/Wimberley
SHORT TERM...JDL
LONG TERM...DEO
AVIATION...Wimberley
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
949 PM CDT Fri Jul 12 2019
.UPDATE...
949 PM CDT
Main concerns for Saturday continue to be the heat and humidity
and threat for widely scattered thunderstorms for portions of the
area in the afternoon and possibly lingering into the early
evening. For the evening update, bumped up temps a bit inland to
mostly 90-93 vs upper around to around 90 from afternoon issuance.
Not expecting scattered to broken Cumulus and some mid-level cloud
cover to be a major impediment to warming. Given dew points rising
to the upper 60s-lower 70s (upper 60s over Chicago and NW IN),
slightly higher forecast temps yields peak heat indices of about
95-101. Thus the message for Saturday will be to remember heat
safety precautions when spending prolonged time outdoors. Lake and
Porter County Indiana also have an Air Quality Action Day in
effect. The backdoor lake enhanced cold front will move in early
enough for the far north shore in Illinois to limit highs to the
lower-mid 80s before continued gradual cooling through the
afternoon.
Turning to convective potential, uncertainty remains the rule on
the 00z guidance thus far, ranging from only a few isolated storms
on 00z HRRR to a more aggressive solution on the NAMs and WRF-NMMb
late afternoon-early evening, particularly the 3km NAM Nest. With
possibility that there is no subtle short-wave forcing and some
capping, it appears there will be a reliance upon lower level
convergence as a source of lift. Only convergence during daytime
hours will be with the lake breeze front itself, so perhaps that
will be a main focus area. The more aggressive solutions do have a
better low level wind convergence associated with the front that
sets up roughly along the I-80 corridor, so observational trends
will be key. At this time, confidence is on the lower side in how
things will play out.
Castro
&&
.SHORT TERM...
155 PM CDT
Through Sunday night...
Concerns through the weekend are centered on thunderstorm chances
Saturday afternoon, as well as notable mid 90s heat index
readings both weekend days.
High pressure centered over the area this afternoon will depart
eastward this evening, taking with it the lake breeze. This should
result in a late day temperature rebound downtown. Otherwise
conditions tonight look quiet with only a slim chance of spotty
convection sneaking in before daybreak. Isolated thunderstorms are
expected across Wisconsin and Iowa overnight, and its the Iowa
activity overnight that may have potential to sustain itself into
north central Illinois, more so after daybreak. It`s a challenge
to tell if there will be any mid-level wave during that time, and
even if so it will be very low amplitude. But enough of a warm
advection regime including steepened mid-level lapse rates and
25-30 kt 700 mb flow, may support sustainability of showers and
isolated convection into far northern Illinois. If this were to
happen, it may play into the chance for isolated/scattered
redevelopment in the afternoon.
A low-level cool front will be sagging southward on Saturday, with
some lake enhancement to it. This feature looks to have boundary
layer confluent flow along it, though convergence itself does not
look that strong except for possibly along the lake enhanced area.
The focus should be into the northern CWA, maybe near I-88/I-290
by mid afternoon.
Temperatures south of the boundary over much of the CWA should
warm to near 90, even if morning mid cloud is thick in the north.
Dew points look to be into the lower 70s given upstream prefrontal
observations. GFS soundings, which were used in the forecast
process, provide afternoon mixed layer CAPE of 1500-2500 J/kg with
this surface air mass. Depending on location in the CWA, that is
up to the convective temperature. Again there is uncertainty in
upstream water vapor on timing of any mid-level impulses which
would slightly further weaken that cap in addition to provide
an area of extra forcing. Any convection that were to develop,
and that`s still conditional, would have the ability to produce
some accelerated downdrafts and gusty outflows with downdraft
CAPEs in excess of 750 J/kg. Any outflows too could easily spark
new convection, resulting in coverage being a little higher if
initiation can occur along the boundary. Have increased forecast
chances for thunderstorms some in this area, but certainly still a
solution is that little to nothing occurs, although that`s become
less of a possibility the past 12 hours.
Any convection will likely slowly wane early-mid evening. There is
some warm advection signature continuing into the overnight and
a few models do regenerate isolated convection and that is a low
confidence solution. High pressure should generally be in control
Sunday, and only maintain some small chances in mainly the south.
Highs look to again be right around 90 with dew points a few
degrees lower than Saturday.
MTF
&&
.LONG TERM...
149 PM CDT
Monday through Friday...
Main weather story this period will be the heat and humidity...
along with low thunderstorm chances throughout much of the period.
Easily the hottest work week of the year thus far is on tap for the
July 15-19 period with temperatures topping out in the lower to
middle 90s each day. The heat coming to us as a result of strong
ridging aloft combined with a southerly flow off the Gulf of
Mexico once the cold front which dropped south of our area late
Saturday and Sunday moves back north as a warm front on Monday.
Will be hard pressed to even see much cooling along the Lake
Michigan shoreline this period with the exception of possibly
Wednesday where winds turning easterly-northeasterly ahead of
approaching low pressure (Barry remnants) bring an on-shore wind.
Given surface dew points returning to the upper 60s with the warm
front passage on Monday... rising to the lower 70s by later in the
week... low temperatures will be oppressive all week. Lows will
hold in the lower to mid 70s most locations each morning... perhaps
75 to 80 in the urban heat island areas of the city by late week.
Remnants of Barry approach the area from the south Wednesday
bringing the best chances of more focused convection of the week.
Heavy rainfall could also be a concern... especially the
southeast portion of the forecast area... depending on how the
Barry remnants track. Otherwise isolated to widely scattered
thunderstorms remain a periodic threat in the very warm and moist
airmass through much of the rest of the work week.
Ed F
&&
.AVIATION...
For the 00Z TAFs...
630 PM...Two primary forecast concerns include...
Chance of thunderstorms Saturday afternoon/evening.
Wind shift to northeast Saturday afternoon.
Southwest winds have increased this afternoon with the lake breeze
moving back to the lake shore. Southwest winds will continue
tonight. Winds will turn more westerly Saturday morning and
should continue turning to northwest by mid/late Saturday
afternoon. At the same time...a cold front enhanced from the lake
will be moving inland across northeast IL. There is still some
timing differences/uncertainty and timing tweaks are possible with
this wind shift.
There remains very low confidence for thunderstorm chances
Saturday afternoon. And timing is also somewhat uncertain. If any
convection develops...its most likely going to be aided by the
lake breeze/front with some potential for activity prior to 21z.
And if anything develops...other thunderstorms may develop on
outflow boundaries with the overall activity perhaps redeveloping
southwest of the terminals as the front moves further inland.
Given the uncertainty opted to maintain current prob timing but
this may need to be shifted a little earlier with later forecasts.
cms
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.
&&
$$
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Area Forecast Discussion
National Weather Service Midland/Odessa TX
606 PM CDT Fri Jul 12 2019
.DISCUSSION...
See aviation discussion below.
&&
.AVIATION...
VFR conditions are expected at the west Texas and southeast New
Mexico terminals the next 24 hours. Included a tempo VFR group
for gusty winds in tsra at KFST through 13/01z.
12
&&
.PREV DISCUSSION... /issued 225 PM CDT Fri Jul 12 2019/
DISCUSSION...
This afternoon, the a subtropical ridge of high pressure remains
centered over/just east of the Four Corners Region, with Tropical
Storm Barry south of the Louisiana coast. These two features will
maintain northeasterly flow aloft the next several days, with a
warming and drying trend anticipated. This afternoon, storms have
started developing over the Davis Mountains and portions of
Brewster county, as well as over the Edwards Plateau. The most
robust storm development through the remainder of the afternoon is
progged across the Davis Mtns, Big Bend Area, and Marfa Plateau.
However, given current trends, expect storm development to follow
the latest HRRR and RAP, with additional development to the
northeast. Thus, have adjusted the forecast to add isolated storm
mention for locations south of I-20 through this evening. Storms
will generally remain isolated, with severe weather not expected.
However, moderate to heavy rain, gusty winds, lightning, and
small hail can be expected with storms that develop. Similar to
the past few days, these storms will weaken after sunset with the
loss of heating.
Looking upstream, midlevel water vapor imagery indicates a warm,
dry air mass that will advect southwestward to the area over the
weekend, yielding warmer temperatures as well as stymieing storm
chances at least through early next week. Temperatures will warm
a few degrees above normal Saturday and Sunday, though light
easterly surface flow should keep most locations below 100
degrees. Guidance trends warmer beginning next Monday through the
end of the forecast period, as surface flow returns to the south.
100s look to return to the Rio Grande and Pecos Valley, and into
SE New Mexico and portions of the Permian Basin by Tuesday and
Wednesday. Confidence in the precipitation forecast is low, given
the GFS brings storms into western portions of the area/across
higher terrain beginning Wednesday, with the ECMWF keeping the
area dry. Have introduced slight chance/low chance PoPs west
beginning Wednesday to account for potential storm development,
also pending better model agreement in later runs. Regardless,
fairly typical summer weather looks to be the rule across
Southeast New Mexico and West Texas through much of the next week.
&&
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 69 94 70 94 / 10 0 0 0
Carlsbad 71 98 70 98 / 10 0 0 0
Dryden 75 99 73 98 / 10 0 0 0
Fort Stockton 71 94 69 95 / 10 0 0 0
Guadalupe Pass 70 90 68 92 / 10 0 0 0
Hobbs 68 96 66 94 / 10 0 0 0
Marfa 61 89 59 90 / 10 0 0 0
Midland Intl Airport 70 95 69 96 / 10 0 0 0
Odessa 70 94 69 95 / 10 0 0 0
Wink 70 98 69 98 / 10 0 0 0
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...None.
TX...None.
&&
$$
44/84
Area Forecast Discussion...UPDATED
National Weather Service Miami FL
742 PM EDT Fri Jul 12 2019
.AVIATION...
Winds will become light and variable tonight over the taf sites
along with mostly dry weather, as the Saharan air continues to work
into the region from the Bahama Islands. The only exception is that
there could be a few light showers over the taf sites through 03Z,
and a few thunderstorms eastern areas Saturday morning. KAPF taf
site should see scattered showers and thunderstorms after 18Z
Saturday. The ceiling and vis should also remain in the VFR
conditions outside of any showers or thunderstorms.
&&
.UPDATE...
Relatively quiet radar for the time being, but HRRR is hinting
that there could be a brief flare up of showers/thunderstorms
early this evening through 03-04Z across the interior and Lake
Okeechobee region before pushing offshore into the Atlantic.
Otherwise, a mostly dry night is expected for South Florida with
an isolated shower or two early morning across the east coast.
Have updated the latest zones to reflect the current trends and
observations.
&&
.PREV DISCUSSION... /issued 321 PM EDT Fri Jul 12 2019/
DISCUSSION...
Hi-Res mesoscale models continue to trend lower in regards to
rain and thunderstorms this afternoon/evening with a swathe of
clouds overhead helping to reduce daytime heating. Kept PoPs at
25-30% across the interior sections, Lake Region, and Palm Beach
County and reduced chances to 10-20% along both coasts.
Regardless, will need to keep an eye on potential thunderstorms
this afternoon/evening for heavy rainfall, especially in areas
that received plentiful amounts already this week. Main hazards
with stronger storms continue to be frequent lightning, heavy
rain, and wind gusts. Party to mostly cloudy skies look to stick
around overnight before thinning out tomorrow. Low temperatures
tonight look to be in the low to mid 70s across the interior/Lake
Region, mid 70s across the Gulf Coast, and mid to upper 70s along
the east coast.
Throughout the weekend, a ridge of high pressure continues to
build and strengthen across the western Atlantic, shifting winds
out of the SE in the process. Drier air also filters into the
region. GFS forecast derived PW`s remain under 2.00 inches with a
pocket of even drier air advecting in from the SE Sunday night
into Monday with values in the 1.20-1.30 range. The Saharan Air
Layer (SAL) looks to stick around Saturday before pushing
northward and offshore Saturday evening. Essentially, the
collaboration between the aforementioned high pressure, SAL, and
drier air will all work together to keep PoPs on the lower end
(40% or less) this weekend into Monday. Keep in mind that there
will still be a chance of showers and thunderstorms as the east
and west coast sea breezes develop and move inland. The greatest
chances of showers and thunderstorms will be located across the
interior and west coast sections during the afternoon and evening
hours.
High temperatures over the upcoming weekend will range from the
upper 80s to lower 90s across the east coast metro areas to the
mid 90s across interior sections. Something that will need to be
monitored over the weekend will be the heat indices, especially
with values encroaching upon the 105-108 degrees range across the
interior and west coast.
The same ridge of high pressure will remain in place early next
week across South Florida. As the middle of the week approaches,
both the ECMWF and GFS continue to show a trough ejecting off the
eastern seaboard. There are still differences between the two
models with this trough as to how fast it moves offshore and how
far south it will actually go, but models are honing in across the
Carolinas/Virgina area. Due to these factors, confidence in the
PoPs in the extended range remains low and this will be monitored
as the week progresses. High temperatures are forecast to stay
near average throughout the period.
MARINE...
Generally southeasterly winds at 10-15 kt will prevail across both
the Atlantic and Gulf waters this weekend. Seas will generally
stay at 3 feet or less. The exception to this will be across the
outer Gulf waters where wave heights could reach 4 feet during the
first half of the weekend. Isolated to scattered showers and
thunderstorms are possible through the forecast period. Winds and
waves could be locally higher in and around any shower or
thunderstorm.
AVIATION...
Showers and storms possible over the interior and Lake region this
afternoon. A few of these storms may move within the vicinity of
PBI and APF. Southeasterly flow across the area except KAPF where
a SW flow with the Gulf sea breeze. Lighter winds overnight with
southeasterly winds around 10 kts tomorrow and mostly dry
conditions for east coast terms.
&&
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 77 90 78 90 / 10 20 10 20
Fort Lauderdale 77 90 80 90 / 10 20 10 10
Miami 77 91 80 90 / 10 20 10 10
Naples 76 91 75 91 / 10 40 10 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
GM...None.
&&
UPDATE...03/Fell
DISCUSSION...03/Fell
MARINE...03/Fell
AVIATION...54/BNB
Area Forecast Discussion
National Weather Service Tucson AZ
217 PM MST Fri Jul 12 2019
.SYNOPSIS...Hot temperatures persist through the weekend and into
early next week. Moisture has also become adequate for the daily
cycle of mainly afternoon and evening showers and thunderstorms,
which will continue into next week.
&&
.DISCUSSION...Isolated showers have begun to develop early this
afternoon, but we`ve yet to see anything of significance so far.
With a mid-level inverted trough south of Tucson to start the day,
the HRRR and other convective allowing models hinted the area around
Santa Cruz County would get going early today. That hasn`t quite
panned out due to lingering cloudiness and the unfavorable position
of a weak MCV from last night`s convection. Temperatures are down
across the board compared to 24 hours ago, while dew points are up
roughly 5-10 degrees.
The overall synoptic pattern anchors the upper high in an optimal
location near the Four Corners region. General southeasterly flow
will persist across our area throughout the forecast period. Minor
shifts in the high position will vary the extent of thunderstorm
development, but we`ve finally settled into the typical monsoon
season expectation of daily afternoon and early evening activity.
Until the lower atmosphere fully moistens up, the primary impact
from any shower/thunderstorm will be gusty outflow winds and the
potential for blowing dust.
Model guidance indicates that thunderstorms become a bit more robust
this weekend as moisture further increases, giving storms a bit more
CAPE to play with. This is followed by a brief downturn early next
week as the high sags south, suppressing convection slightly. By
midweek a long fetch of moisture with tropical origins works up the
Gulf of Mexico/Sonora and eventually into our area, kicking off the
potential for more widespread development. However, ensemble
guidance doesn`t indicate anything particularity anomalous regarding
PW and this holds true throughout the entire forecast period.
&&
.AVIATION...Valid through 14/00Z.
Isolated to scattered -TSRA/-SHRA through about 13/04Z, then once
again developing after 13/18Z. Brief gusts of 40-45 kts possible
vicinity stronger TSRA. BLDU may also reduce VSBYS down to 1-3 SM.
Otherwise, cloud decks generally 9k-14k ft MSL. Surface wind less
than 12 kts thru the forecast period, favoring a ELY/SELY direction.
There will be some afternoon and early evening gusts to around 20
kts. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...With increasing moisture across the area, isolated
to scattered mainly afternoon and evening showers and thunderstorms
are expected across the region through the weekend. As the moisture
increases, the potential is there for more substantial wetting
rainfall with the thunderstorms. A slight downturn in activity is
expected early next week before favorable conditions return mid to
late next week. Wind speeds will generally be less than 15 mph into
next week, outside of any gusty outflow winds. Strong, gusty and
erratic outflow winds to 45-50 mph are possible with any
thunderstorms that do develop.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
Discussion...Howlett
Aviation/Fire Wx...Lader
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