Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/14/22

Area Forecast Discussion

National Weather Service Billings MT

947 PM MDT Wed Jul 13 2022

.UPDATE...

All severe storm potential has diminished from the area. Hence the
rest of thunderstorm watch 468 has been cancelled. Vertz

.DISCUSSION...
Tonight through Thursday night...

While a strong ridge remains in place across the Northern Rockies,
the axis is far enough east that the area is under southwesterly
flow. With a weak shortwave moving around the the ridge,
thunderstorms have begun to develop over western Montana. Most of
the CAMs guidance still as the majority of the stronger winds
going west and north of the area. However, the HREF and the runs
of the HRRR since 12Z continue to show a chance for some isolated
winds across the northwest with gusts 55 to 60 mph. However, the
calibrated severe wind potential guidance from the HREF does not
show the potential in southern Montana. Likely looking at an
isolated potential for a stronger storm.

Temperatures are into the mid 90s with a few more hours of heating
to go today, so still looking at temperatures up near 100 for
highs today. The Heat Advisory will continue until 8 PM this
evening.

Thursday should be cooler behind the weak disturbance today, which
will knock 5 to 10 degrees off the highs. With less energy moving
through as well, expecting that the shower and thunderstorm
activity will be much lower tomorrow, mainly along the Wyoming
state line. Reimer

Friday through Wednesday...

In general, upper ridging will prevail over the area through the
period. On Monday, there were timing differences in the clusters
regarding a shortwave moving through the ridge. NBM predicted
record highs for Sunday and a heat highlight may be needed.
Otherwise, weak disturbances will move through the upper ridge,
generating isolated to scattered thunderstorms Friday afternoon
and evening, and more thunderstorms over and near the western
mountains Sunday and Monday. Meteograms painted Monday as a windy
day and NBM reflected this forecast. Cannot rule out some stronger
storms Friday due to MLCAPE and shear values, as well as PWAT`s
above 1 inch over the E half of the area. Very warm weather is
forecast for most of the period. Arthur
&&

.AVIATION...

All severe storm activity has diminished. However, the widespread
rain over the mountains and foothills of southern MT and northern
WY could still produce outflows with gusts to 50 mph, with KSHR
having a small chance of that occurring through early Thursday
morning.Low- level wind shear will develop around MLS late this
evening and decrease by early morning. VFR conditions will
generally prevail, but thunderstorms could produce localized MVFR
to IFR conditions. Reimer/Vertz

.PRELIMINARY POINT TEMP/POPS...

Thu Fri Sat Sun Mon Tue Wed
-----------------------------------------------------------
BIL 067/093 065/096 064/096 066/102 068/097 062/092 062/094
41/U 23/T 21/U 11/G 11/U 11/U 11/U
LVM 058/091 058/092 056/093 059/097 060/094 055/090 056/093
24/T 24/T 21/U 11/U 22/T 11/U 11/U
HDN 065/094 063/098 063/098 065/103 067/099 061/092 060/096
41/U 22/T 21/U 11/G 11/U 11/U 11/U
MLS 070/094 068/098 066/095 068/102 072/098 064/090 061/094
50/U 13/T 30/U 10/G 10/U 10/U 10/U
4BQ 070/094 067/098 066/094 067/100 072/098 064/091 062/093
20/U 23/T 31/U 11/U 10/U 10/U 11/U
BHK 067/090 064/092 063/091 066/097 069/094 063/087 060/090
41/U 12/T 41/U 10/U 10/U 20/U 10/U
SHR 065/093 063/095 062/093 063/100 067/097 061/090 060/093
32/T 33/T 31/U 11/U 11/U 21/U 11/U

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.

$$
weather.gov/billings

Area Forecast Discussion

National Weather Service Duluth MN

628 PM CDT Wed Jul 13 2022

.UPDATE...
Issued at 622 PM CDT Wed Jul 13 2022

No significant changes with this forecast update. The main
challenge will be if marine fog develops and moves inland
especially for the Twin Ports and across the South Shore. Some
hints of fog are seen in the visible imagery near buoy 45006 early
this evening, otherwise, the HRRR has been too aggressive early
this evening in its marine fog development.

.DISCUSSION...(This evening through Tuesday)
Issued at 333 PM CDT Wed Jul 13 2022

Summary: The latter half of the week is expected to be relatively
quiet with a chance for rain on Thursday night into Friday.
Temperatures this weekend are expected to become very warm with
highs in the 80s and some 90s. This is likely to continue into next
week with periodic chances for showers and thunderstorms.

Cloud cover has been on the decrease this afternoon as sfc high
pressure builds north of the CWA in Ontario. Expect a quiet night
tonight with mostly clear skies and low temps in the mid 40s to mid
50s. High pressure remains in control of the pattern for much of
tomorrow, resulting in partly to mostly clear skies. Weak WAA
resulting from south-southeasterly flow will lead to slightly warmer
highs tomorrow in the mid 70s to low 80s. Expect cloud cover to
increase in the afternoon and evening ahead of an approaching
shortwave trough.

This shortwave will propagate through the CWA on Thursday night and
into Friday morning. This may lead to scattered showers and
thunderstorms during this time period, mainly for the southern half
of the CWA. The best synoptic forcing associated with this trough
will likely be located south of the area, with maxima of both omega
and low-level FGEN being outside of the CWA. In addition, moisture
in the low to mid levels will also be limited in the northern half
of the CWA. CAMs reflect these synoptic conditions, with most of the
precip being concentrated south of the CWA. However, scattered
showers and an isolated thunderstorm or two may still move through
late Thursday into early Friday.

Following the shortwave on Friday, a longwave ridge aloft is
expected to settle over the central CONUS. This will likely result
in above normal temps for Sunday and most of next week. NAEFS
percentiles reflect this with temps in the 90th percentile of
climatology for the CWA from Sunday through next Wednesday. Highs
during this time frame will likely be in the 80s and potentially
even a few 90s. Precip chances during this period of prolonged
ridging will likely be limited. The best chance for rain from this
weekend through early next week will be on Tuesday, as a shortwave
moves through.

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 622 PM CDT Wed Jul 13 2022

VFR conditions are expected for the 00Z TAF cycle for northeast
Minnesota and northwest Wisconsin. The one exception will be if
marine fog develops over Lake Superior and moves inland, which
could impact KDLH. However, confidence in the fog formation is low
at this time. Otherwise, VFR cumulus fields will fade with sunset
this evening, and generate again by late Thursday morning.

.MARINE...
Issued at 333 PM CDT Wed Jul 13 2022

Tonight and tomorrow will be relatively quiet in terms of wind and
waves as high pressure remains over the region. Winds over the next
48 hours will be predominately from the northeast at 5 to 10 knots.
The exception will be from Chequamegon Bay to Saxon Harbor, where
winds of 5 to 10 knots will likely be from the south to southeast.
Waves are likely to remain at 2 feet or less.

.PRELIMINARY POINT TEMPS/POPS...
DLH 48 72 54 79 / 0 0 30 30
INL 52 78 58 84 / 0 0 20 20
BRD 55 81 64 85 / 0 0 50 20
HYR 49 81 57 83 / 0 0 40 30
ASX 45 74 50 82 / 0 0 20 30

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&

UPDATE...PA
DISCUSSION...Unruh
AVIATION...PA
MARINE...Unruh

Area Forecast Discussion

National Weather Service Gray ME

1042 PM EDT Wed Jul 13 2022

.SYNOPSIS...
A low pressure system will rotate through the region on Thursday
bringing scattered showers and thunderstorms. This system will
give way to high pressure on Friday with dry weather and
seasonably warm temperatures expected through Saturday. By
Sunday and into early next week...humidity will increase with
the potential for some hot weather along with increasing chances
for showers and thunderstorms.

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...

10:40PM Update...

Updated POPs to bring showers into southwest New Hampshire a
little earlier tonight. Showers and storms have remained
widespread to our southwest across New York this evening. These,
along with a few thunderstorms, will likely scrap southern New
Hampshire over the next few hours, with the heaviest showers
remaining south of the area.

7:15PM Update...

Mostly just a quick update to better fit precip trends from the
latest guidance with the showers arriving after midnight. Also
fit temperatures with the latest trends as the seabreeze front
weakens this evening. Overall the forecast remains on track at
this time.

Previous...

Aside from the chance of a isolated shower or two through late
afternoon in the interior, the evening should wind down with
daytime cu decreasing in coverage.

Light winds continue tonight, as a weak wave drifts east out of
the Great Lakes. Trough aloft will run into baroclinic zone to
the east, slowing down as the wave enters New England. Clouds
will thicken and lower as this approaches, with showers
developing in southern NH after midnight. With some elevated
instability, a few rumbles of thunder cannot be ruled out
before daybreak. However, the main chance of thunder will come
during the afternoon.

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
Weak low pressure will be moving over the area Thursday. This
lift ahead should allow for the development of some rain showers
to train across much of the CWA through the morning and early
afternoon. HRRR runs have been quite progressive with this,
where as the NAM a bit slower. Some of these showers could have
moderate downpours, perhaps better coverage than Tuesday`s
storms, but there is some question as to how filled in and
efficient precip will be given dry air aloft. This cloud cover
should be enough to temper highs tomorrow, and have gone below
guidance for maximums.

Another point advertised by some of the short term guidance is
convection. The region will still be beneath a lot of shear
ahead of the upper trough. There will also be a upper jet
reaching back along the ME coast providing some other lift as
the low passes. The question box is instability, but model
soundings display this as being enough aloft to mention thunder
chances. Surface based is a bit of a question mark. Will need to
overcome morning clouds and cooling to tap into potentially
stronger storms. 00z and 12z HREF runs did display a few
clusters of UH plumes for consistency, and will keep an eye on
instability trends to weigh the need for any enhanced wording.
SHIP values are non-zero, and that is usually a clue to some
hail production in storms that do strengthen.

Low will move northeast by the evening with thunder and shower
chances dwindling. Some fog may come on shore in the Midcoast,
but otherwise remain over the waters.

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
High Impact Weather Potential: Increasing chances of heat indices
nearing advisory thresholds by the end of this weekend or early next
week. Otherwise...high astronomical tides continue into Saturday
with no other significant high impact weather threats at this time.

--Pattern and Implications--

The long term forecast period opens with a longwave trough along the
east coast of North America...ridging along the spine of the Rockies
and another substantial trough just off the west coast of Canada.
Little in this pattern looks to change through the weekend...though
the trough overhead will relax with slowly building heights and
warming temperatures. Early next week...there is good ensemble/
deterministic guidance agreement that the trough off the west coast
will temporarily erode the ridge. This will work to kick a weak
shortwave over the Mississippi Valley eastward with possible
sensible weather impacts. Also..there is less agreement that even
warmer air may get tugged east from the western ridge.

--Daily Details--

Friday - Saturday: Modestly dry airmass pushes overhead for the
Friday-Saturday period with a surface high over upstate NY on Friday
cresting over or just south of our area Friday night and then moving
southeast of New England on Saturday. T8s warm from around +11C
Friday to +14C Saturday. With ample sun...this should allow highs
to reach the middle 70s to lower 80s on Friday with readings moving
up into the upper 70s to middle 80s on Saturday.

Sunday - Monday: With surface high pressure well south and east
of the region for Sunday/Monday...broad west southwest flow is
expected across the region with low level trajectories favoring
increasing humidity with T8s continuing to climb through the mid
teens. EPS Extreme Forecast Indices have a signal for
heat...with any headline potential largely tied to how much
boundary layer humidity we can realize. Dewpoint increases have
lagged guidance this summer given ongoing drought
conditions...but there is some potential as highs reach 90F over
southern New Hampshire that heat indices may near 95F. As for
precipitation chances...a weak front looks to reside north of
northern New England on Sunday...washing out as it arrives
Monday. Thus...afternoon shower/storm chances look to gradually
increase...though no real organized forcing suggests that the
chance for widespread wetting rainfall will be low.

Tuesday - Wednesday: The end of the long term forecast period
continues to look very warm with temperatures above normal in an
increasingly zonal flow pattern. T8s build into the upper teens with
some ensemble members moving above +20C. Thus...highs in the 80s to
lower 90s look good at this distant range with time to refine as we
gain confidence in the cloudiness/precipitation details. There is
decreasing agreement within the deterministic/ensemble guidance
suite as to the timing/location of shortwaves within this flow. With
a weak frontal boundary in the area...some PoPs / just a bit above
climatological values/ seems in order with the highest values to the
north closer to stronger mid/upper level flow and thus implied
forcing.

.AVIATION /03Z THURSDAY THROUGH MONDAY/...
Short Term...VFR. There will be another chance for some valley
fog after midnight, but arriving clouds and showers may limit
this. -SHRA Thursday, with some VCTS possible in the morning,
and again the afternoon across most sites. Believe western NH
terminals will deal with TS the least.

Some fog will be possible along the Midcoast at KAUG and KRKD
Thursday evening and night.

Long Term...VFR conditions look to dominate the long term
forecast period through at least Sunday morning. There is the
slight chance for a pop up shower or thunderstorm on Sunday with
a better chance for showers and storms and associated
restrictions on Monday. By Sunday night...some overnight fog
will be possible as well...particularly HIE/LEB. Winds are
expected to remain light through the period.

.MARINE...
Short Term...Below SCA conditions continuing. Some fog over the
waters will return Thursday evening and overnight. Cannot rule
out a few rumbles of thunder along the coast during Thursday
afternoon.

Long Term...Quiet on the waters through Saturday. By
Sunday...southwesterly winds may result in a period of SCA
conditions over the outer waters with winds/waves subsiding into
Monday.

.TIDES/COASTAL FLOODING...
High astronomical tides will continue this week. Residual
elevated waters may allow water levels to approach flood stage
from Portland south through Hampton New Hampshire tonight. Have
continued a coastal flood statement for the high water levels
and the potential for very minor coastal flooding.

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.

$$
SYNOPSIS...Arnott
NEAR TERM...Clair
SHORT TERM...Cornwell
LONG TERM...Arnott
AVIATION...Arnott/Cornwell
MARINE...Arnott/Cornwell

Area Forecast Discussion

National Weather Service Houston/Galveston TX

655 PM CDT Wed Jul 13 2022

.AVIATION [00Z TAF Issuance]...
Iso-sct precip looks to be winding down as we lose some heating.
Will be keeping our eye on trends to the northeast overnight as
some of the model guidance depicts some precip trying to make it
into the area late tonight & early morning. Not advertising this
in the TAFs at this time however.

On Thurs, mid-upper ridge slightly retreats to the nw and an
inverted trof makes its way toward the area from the east bringing
some higher moisture levels to the region. Would anticipate some
radar returns popping up offshore toward morning. With a less
hostile profile for precip in place, would anticipate some sct
tstm development inland as convective temps in the 92-97 degree
range are met during the day. Fcst soundings depict somewhat of
an inverted-v profile so gusty winds would be a decent bet
in/near any stronger cells. Outside of any convection, VFR
conditions should prevail thru the period. 47

.PREV DISCUSSION /Issued 409 PM CDT Wed Jul 13 2022/...
.SHORT TERM [Tonight through Thursday Night]...
Showers and thunderstorms have started to develop mainly along the
seabreeze this afternoon. Another feature producing forcing and low-
level instability across the region is a stationary frontal boundary
currently extending north of TX. With daytime heating and increasing
low-level instability (7-9 C/km), showers and storms are expected
through sunset. Expect brief downbursts, lightning and isolated
damaging winds with any stronger storms. An isolated strong to
marginally severe storm or two will be possible, mainly north of I-
10.

Clouds will be on the increase tonight, leading to another warm and
muggy night. Heights aloft weaken over the region as the ridge
slightly moves west on Thursday. This will allow for a sfc trough
over the Louisiana region to further moves west into our area during
the day. Confidence still remains low to moderate as Hi-Res
models/CAMS are not in good agreement with this possible MCS. The
WRF-ARW and FV3 bring most of the activity over the region while the
HRRR and TX-TTU-WRF keep the bulk of this convection over the
coastal waters. Have increasing rain/storm chances beginning early
in the morning and continuing into early Thursday evening. Severe
weather is not anticipated but heavy downpours, lightning and strong
winds can be expected with any stronger storms.

In terms of temperatures, the heat continues, though it won`t be as
hot as the previous days. Temperatures are expected to climb from
the upper 90s to around 103 degF, with the hottest readings along
the Brazos Valley. Have extended the Heat Advisory for our western
counties through 8PM Thursday. 05

.LONG TERM [Friday through Wednesday]...
Our weather will continue to be dominated by a large mid to upper
level ridge through the foreseeable future. This will continue to
skew temperatures above average. Diurnal and seabreeze related
shower and thunderstorm activity will be possible on Friday through
Monday. Morning showers and thunderstorms are possible near the
coast on Friday due to the approaching weak trough that is
currently over the northern Gulf. The eastern edge of the ridge
is expected to erode on Sunday and Monday resulting in a modest
decrease in 500 mb heights. This would suggest slightly cooler
temperatures on those days. Perhaps we can manage a day or two of
normally hot temperatures. But normal July heat in southeastern
Texas is still quite uncomfortable.

Beyond Monday, we continue to opt for above average temperatures and
low PoPs. Most long range guidance suggest that ridging will build
over the region. This would result in rising temperatures and the
potential for widespread triple digit heat once again. Our
forecast reflects this through a gradual rise in temperatures on
Tuesday and Wednesday. By Wednesday, our grids show low-100s for
most areas that are north of I-10 and west of I-45.

With another hot week expected, we could be talking about more heat
advisory days. However, it is worth mentioning that heat safety
should practiced regardless of whether or not there are heat related
advisories or warnings. Drink plenty of water. Take breaks in the
shade or indoors. LOOK before you LOCK. Don`t forget about heat
safety for you pets. Self

.MARINE...
Light to moderate winds will persist over the next several days.
Wind direction will generally be onshore with the typical diurnal
shifts. Widely scattered shower and thunderstorm activity is
possible through the weekend.

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 79 103 77 102 78 / 20 40 10 10 0
Houston (IAH) 78 99 77 97 77 / 10 30 20 20 10
Galveston (GLS) 84 93 82 95 84 / 20 20 20 30 10

.HGX WATCHES/WARNINGS/ADVISORIES...

TX...Heat Advisory until 8 PM CDT this evening for the following
zones: Bolivar Peninsula...Brazoria
Islands...Chambers...Coastal Brazoria...Coastal
Galveston...Coastal Harris...Coastal Jackson...Coastal
Matagorda...Fort Bend...Galveston Island...Inland
Brazoria...Inland Galveston...Inland Harris...Inland
Jackson...Inland Matagorda...Matagorda
Islands...Montgomery...Northern Liberty...Polk...San
Jacinto...Southern Liberty...Trinity...Wharton.

Heat Advisory until 8 PM CDT Thursday for the following zones:
Austin...Brazos...Burleson...Colorado...Grimes...Houston...Madison...Walker...Waller...Washington.

GM...None.

Area Forecast Discussion

National Weather Service North Platte NE

644 PM CDT Wed Jul 13 2022

.SHORT TERM...(This evening through Thursday night)
Issued at 412 PM CDT Wed Jul 13 2022

Near-term forecast concerns focus on the potential for isolated
strong storms /mainly Thursday evening/. Near record heat tomorrow
headlines greatest concern with the impacts potentially lasting each
day event through the extended periods.

Late morning satellite imagery over Nebraska shows mostly clear
skies with the exception of decaying cumulus over far SW Neb from
early am convection out across the panhandle. Expanding out to
include the CONUS, evident is the expansive ridge that is centered
across the southwest with your typical diurnally driven convection
already popping over the Rockies and Desert region. East of
Nebraska, increased cloudiness associated with a Great Lakes trough
was noted over Lake Michigan with another complex of storms centered
across northern Alabama and Mississippi. The convection has sent
off an impressive outflow that is diving south toward the Gulf.
Largely absent across the plains is the presence of clouds as
expansive subsidence and warm temperatures aloft limit vertical
development.

Regarding the isolated thunderstorm potential this evening and
overnight...current satellite shows CU`s developing along the Rocky
Mountain front from Wyoming south through Colorado. The latest CAMS
dissipate the storms before venturing across southwest Nebraska,
though the latest NamNest maintains storms into the area from
northeastern Colorado. Didn`t want to pull pops all together from
our SW, but we feel storms would be isolated at best /if even at
all/. The environment would favor strong storms with some downdraft
potential. Otherwise the better chances for precipitation lie
Thursday evening and overnight as northern stream wave taps into sub-
tropical monsoonal moisture from the southwest. The environment
once again would favor strong downdraft potential with inverted
soundings in the lowest 12k feet. It should be noted that ensemble
members are largely dry for most areas, but we are maintaining
widespread 30% pops Thursday evening. Shear is not overly
impressive, so upgrowth to a convective complex is not anticipated.
Bottom line, those who see storms may get some beneficial moisture,
but most areas will be dry.

Triple digit high temperatures return to west central Nebraska on
Thursday as heights aloft continue to build. H5 heights across much
of west central Nebraska will exceed the 90th percentile of
climatology with H7 showing a similar vibe. Collaborated with
neighbors on a heat advisory, but there`s questions as to how much
TD/s will lower during the afternoon. For reference, the HRRR would
suggest mid 40 TD/s at KLBF by mid-afternoon. Obviously they
shouldn`t lower that low, but it sure muddles the decision. We
lowered TD/s slightly from inherited, but if just a degree or two
lower, enough dry air would suggest no heat advisory criteria. One
last note, a record high air temperature or two may fall tomorrow.
We are close at KLBF.

.LONG TERM...(Friday through Wednesday)
Issued at 412 PM CDT Wed Jul 13 2022

The main story in the long term periods is the continued above
normal temperatures with the possibility of record breaking heat.
There is a low potential for the typical afternoon through overnight
convection, but at that, nothing of significance is seen at this
point.

Very little change will occur in the positioning of the ridge, with
the center fixed to the Four Corners and the northern tier jet near
the Canadian border. There is good agreement that a couple potent
PV anomalies will traverse the Northern Rockies and lift northeast
across the northern plains this weekend and next week with attendant
cold fronts pulled south across the plains. Ensembles are in good
agreement with the pattern, so precipitation chances are not out of
the question, but lacking is the strong forcing for widespread
chances. The best opportunity to see a wetting rain will come
Saturday, though again for most locations the clustering of
precipitation amounts are less than a tenth of an inch to a quarter
of an inch. The wave will "cool" us off slightly for the weekend.

It should be noted that with the ongoing drought and convective
potential in place, dry lightning and attendant rangeland fire
starts are not out of the question. Despite the occasional wind
shift, a relatively quick return to southerly will help keep minimum
relative humidity generally above critical thresholds for a RFW. The
exception being zones 210 and western portions of 219 where RH will
fall below 20% next week. At this point, sfc features do not favor
RFW wind events.

Temperatures continue to be warm through the end of the extended.
Records may be broken on Monday, if not other periods as well. Long
range guidance and CPC outlooks suggest that the heat will persist
well beyond the extended. I guess it/s payback time for complaining
about the cold temperatures last January.

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 642 PM CDT Wed Jul 13 2022

VFR conditions are expected over the next 24 hours. Isolated
thunderstorms are possible in parts of the Panhandle and southwest
Nebraska this evening, some of which may bring gusty erratic winds.
LLWS will develop in portions of southwest and north central
Nebraska overnight. Winds will be less than 10 knots after midnight
and shift from the southeast to the south by tomorrow morning.
Another wind shift will occur later tomorrow morning and afternoon
as a trough moves through and winds shift to the west, then the
north.

.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&

SHORT TERM...Jacobs
LONG TERM...Jacobs
AVIATION...Meltzer

Area Forecast Discussion

National Weather Service Lake Charles LA

1056 PM CDT Wed Jul 13 2022

.DISCUSSION...

Have adjusted evening/overnight POPs a couple of times this shift
based on radar trends as latest high res guidance doesn`t seem to
have a great handle on convection moving into the nrn zones at
this time.

Elsewhere, inherited grids/zones look fine per obs/trends.

Zone updates already issued.
25

.PREV DISCUSSION... /issued 705 PM CDT Wed Jul 13 2022/

DISCUSSION...

For the 07/14/2022 0000 UTC TAF package.

AVIATION...
Precipitation has largely come to an end across the region late
this evening and with temperatures now cooling, expect little
additional development over the next few hours. Short range
guidance continues to indicate that outflow from some of the
strong to severe storms further north will initialize storms
across central Louisiana after midnight tonight which will then
work south. This has been consistent enough to explicitly include
in the tafs, but the exact timing and extent of coverage remains
uncertain. Expect a brief lull in storms once this activity passes
until additional storms begin developing by mid Thursday morning
due to daytime heating.

Away from storms, winds will remain generally light out of the
south through the period, but may turn briefly out of the north
early Thursday morning should the aforementioned outflow
boundaries develop and push south as expected.

PREV DISCUSSION... /issued 353 PM CDT Wed Jul 13 2022/

SYNOPSIS...

Surface analysis shows a weak boundary north of the area, with
weak ridging across the Gulf of Mexico. Fcst soundings suggest
considerable moisture over the region with PWATs between 1.8 and
2.0 inches, and this roughly corresponds to recent LAPS Layer
Precip Water analysis and GOES TPW imagery. While these values
aren`t quite as high as they have been over the past week or so,
they still reflect above normal moisture across the region.

This, along with daytime heat and convergence along mesoscale
boundaries, has aided in the development of some isolated showers
and storms across the area. Outside of any cooling showers,
temperatures are again quite hot, with readings in the upper 90s
or around 100 degrees across much of the area with the exception
of the I-10 corridor of SW and S Cntl LA where temperatures are in
the lower 90s. Heat index values in many locations this afternoon
have exceeded 100 degrees, with several sites between 105 and 110
degrees. A Heat Advisory remains in effect through 8 PM this
evening for SE TX as well as Vernon, Rapides and Avoyelles
Parishes.

SHORT TERM [Tonight through Friday]...

Convection developing through the latter part of the afternoon
should come to an end around sunset, with quiet conditions through
the rest of the evening. HiRes and regional models point to PoPs
increasing again after midnight as outflow driven convection from
storms currently forming across N/Cntl MS moves into the area.
Meanwhile, convection over the coastal waters is also expected to
expand in areal coverage overnight, spreading inland toward the
I-10 corridor prior to sunrise. Atmospheric conditions remain
supportive for all of this to happen as the region remains in a
moist and fairly buoyant airmass beneath a weakness aloft locked
between stout ridging to the west of the region and the western
edge of the Bermuda ridge across FL.

Coverage and timing of overnight storms across northern portions
of the area remains somewhat uncertain, with considerable
discrepancies among CAMs. ARW and NAMNest both appear overdone
with respect to coverage and even the intensity of convection,
while the HRRR and FV3 are both far less pronounced with coverage
and show later onset. Opted to blend the guidance from the latter
2 models with NBM to reflect a steady but not overly robust
increase in rain chances overnight across our northern zones.

Thursday looks to be a little better day for more widespread
showers and storms across the area, especially with lingering
boundaries leftover from convection late this afternoon as well as
tonight. The ridge that has brought oppressive heat the past
several days will retreat further west, allowing the
weakness/shear zone aloft to become oriented a little more over
the area. With decreased inhibition, convection will likely
initiate a little earlier in the day as heating gets underway. A
similar setup is expected for Friday, although overall coverage
will be slightly less than on Thursday as the ridge west of the
region begins to nudge the weak trough aloft back to the east.

Beyond the better chances for rainfall, this situation should
also finally bring an end to the abnormally hot temperatures
across the area. The increase in clouds and showers should
mitigate the excessive heat and keep daytime highs on Thursday and
Friday between the upper 80s to lower 90s across much of the
area. Little change is expected in overnight temperatures however,
with lows in the 70s each night.

LONG TERM [Saturday through Wednesday]...

The region will remain between a mid to upper level ridge over the
Western U.S. and a mid to upper level trough over the Eastern U.S.
At the surface, the Bermuda high pressure ridge will continue across
the Southeastern U.S. and across the Northern Gulf. This will keep a
light onshore flow through Sunday, increasing a bit during the late
afternoon and evening hours with the seabreeze. For Monday through
Wednesday, a tighter pressure gradient between the strengthening
Bermuda high and the broad low pressure trough over the Midwest will
generate slightly higher south to southwesterly winds over the
region.

Expect enough low level moisture coupled with the lift from the
afternoon seabreeze to provide isolated to scattered showers and
thunderstorms each day. Blended guidance show Sunday and Monday with
the highest chances. For distribution across the area, the highest
chances remain over South Central Louisiana, and the lowest chances
over Inland Southeast Texas and Central Louisiana.

Afternoon highs in the lower to mid 90s across Inland Southeast and
Central Louisiana, upper 80s to near 90 along and south of the I-10
corridor. Lows in the mid to upper 70s, with near 80/lower 80s along
the coast.

08/DML

MARINE...

A light to occasionally moderate onshore flow will continue
through early next week. Scattered to numerous showers and
thunderstorms can be expected mainly from late night through
early afternoon for the next several days as an upper level
disturbance meanders across the northern Gulf.

LCH WATCHES/WARNINGS/ADVISORIES...
LA...Heat Advisory until 8 PM CDT this evening for LAZ027>029.

TX...Heat Advisory until 8 PM CDT this evening for TXZ180-201-215-216-
259>262.

GM...None.

.PRELIMINARY POINT TEMPS/POPS...
AEX 73 92 72 94 / 40 50 30 20
LCH 75 88 74 88 / 20 70 40 50
LFT 76 88 74 90 / 10 70 40 70
BPT 76 90 75 91 / 20 60 30 40

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...None.
&&

Area Forecast Discussion

National Weather Service New Orleans LA

701 PM CDT Wed Jul 13 2022

...New AVIATION...

.SHORT TERM (This afternoon through Thursday Night)...

Branching off this morning`s update focusing in on this
afternoon/evening, we will continue to see convective initiation
across portions of the I-10/12 corridor south into SE LA through
the rest of today. Location and propagation will be determined by
small- scale boundary interactions likely from the northward
surging boundary reaching the Northshore, as well as lake breeze
boundary development as seen my GOES-16 VIS. Main threats will
remain to be localized flooding from these interactions, with slow
but somewhat progressive WSW to SW mean storm motion. However,
due to relatively weak mean storm motion, training/backward
propagation could be possible leading to flash flooding in some
areas especially within complex boundary interactions. Main focus
will remain across the central portions of the CWA or along/near
I-10/12 along the leading edge of deeper tropospheric moisture and
a differential heating boundary from a cirrus canopy over coastal
SE LA to coastal MS. This, coinciding with mid-level vorticity
/upper-level deformation all supportive of convection to persist
into the evening hours. Recent mesoanalysis trends illustrate
DCAPE surpassing 1000-1100J/kg already extending from the
Atchafalaya Basin, ENE across the MS coast as mid-level dry air
continues to bleed south. As isolated/scattered convection
develops later today, any locally stronger updrafts tapping into
this dry layer will lead to evaporative cooling/downward transport
causing a wet microbursts potential. At this time, winds should
remain sub- severe but can`t rule out stronger (40-50mph) isolated
gusts from any stronger storms (also given THI in the mid/upper
30`s).

Will be monitoring upstream convection as well this evening, as a
remnant outflow boundary will continue to ignite messy convection
across central MS/AL. Mean storm flow will be from the north,
meaning if any convection becomes deep enough to develop cold
pooling (which could be likely given the proximity of
environmental dry air and downward transport potential), they
could drift south close to or within our northern areas. CAM`s do
not have storms entering our CWA as we lose diurnal support later,
but cold pooling could continue southward propagation into
atleast SW MS/Florida Parishes this evening so might be something
to watch.

Otherwise, turning dry tonight. Going into Thursday, recent
thoughts have been on the potential or a weak frontal boundary to
make it`s way south. However, not seeing a clear enough indication
of an actual defined boundary to call it much of a front. The
main focus will be the slow/steady return of a corridor of deeper
tropospheric moisture/association dynamic ascent drifting north
across the CWA. However, in the mean time mid-level flow
transitions more out of the north helping to amplify upper-level
deformation owing in greater dynamic lift potential. One
plausible solution came out of the 12Z HRRR today which follows
suit with this steady environmental transition, illustrating more
widespread coverage and the potential for small cold-pool driven
storm clusters to dive south throughout the day. One thing to also
closely watch will be how this re-enforcing mid-level northerly
push of dry air penetrates into our area within developing
convection leading to a slight uptick in strong (sub-severe) wind
gust potential. Hard to say as CAM`s continue to struggle overall,
but will be worth monitoring. However, storm motions largely
collapse within an equilibrium of vertical winds aloft meaning
any propagation would be confided to local boundary surges but
again, complex interactions may likely lead to training and given
the northward surge of PW`s (in the 2.1-2.3" range), intense rain
rates will become a heightened concern leading to a localized
flash flooding risk with again most activity coming to an end in
the evening hours. KLG

.LONG TERM (Friday through Wednesday)...

Mid-level dry air tries to take over a bit more into the CWA on
Friday as we reside on the southeastern periphery of a deep,
strong western US ridge closed off over the four-corners region.
This will create yet another tight corridor of high PW`s along
central/coastal portions of the CWA to slightly drier air up
north. Question again will be how far this drier air bleeds south
to entrain into afternoon pop-up convection but overall, seeing a
similar day compared to Thursday with the same risks for flash
flooding persisting along with occasionally gusty winds in any
stronger storms.

Going into the weekend, a strong upper-level low over the Bahamas
will continue drifting NW across the Florida Atlantic coast with
northwesterly flow persisting across the northern Gulf states.
Will have to monitor several mid-level impulses riding along the
outer periphery of the ridge from the north/central Plains,
southeast into the Mid MS valley potentially getting into the SE
US. Hard to determine where eventual impulses/clusters or
complex`s of storms will end up, but will be something to monitor
outside of daily pop-up storm chances.

This aforementioned upper-low near Florida continues to drift
northwest into a region of mid-level weakness over the SE US, with
a slow/steady weakening trend overall but still may support an
uptick in rain chances going into next week. Hard to pinpoint
individual threats, but if you are not tired of the rain then you
are in good luck because we`ll keep this summertime shower/storm
chances going for atleast the next 7 days. KLG

.AVIATION...
(00Z TAFS)
Issued at 653 PM CDT Wed Jul 13 2022
VFR conditions are expected for most terminals outside of
thunderstorm or fog issues (for MCB primarily). The northern
terminals do have a secondary threat of thunderstorms tonight due
to some scattered cells moving into SW Mississippi and then SE
Louisiana in the next few hours. There is some uncertainty on how
far south these storms will be able to reach, so will amend tempo
groups as necessary. -BL

.MARINE...

Ongoing widespread shower/storm chances will persist through late
week, into the weekend and into early next week, with greater
convective coverage in the overnight to morning hours each day.
Main threats in any one storm will continue to be gusty, erratic
downdraft winds leading to locally enhanced waves/seas,
waterspouts and dangerous lightning. Winds outside of
showers/storms will remain light to occasionally breezy at around
5-10kt with seas 1-3ft. KLG

.PRELIMINARY POINT TEMPS/POPS...
MCB 73 89 71 90 / 40 70 30 60
BTR 75 90 73 91 / 30 80 30 70
ASD 75 90 73 90 / 30 90 50 80
MSY 77 88 76 88 / 40 90 50 80
GPT 75 88 75 88 / 40 80 60 80
PQL 75 87 74 87 / 40 80 60 80

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
MS...None.
GM...None.
&&

Area Forecast Discussion

National Weather Service Chicago/Romeoville, IL

634 PM CDT Wed Jul 13 2022

.SHORT TERM...
Issued at 333 PM CDT Wed Jul 13 2022

Through Thursday night...

Visible satellite imagery and KLOT radar reflectivity show a
well-defined lake-enhanced back door cold front making a push
inland through northeast Illinois and northwest Indiana this
afternoon. A few showers had developed along the southern, more
zonally-oriented portion of the front early this afternoon but
have since fizzled, while farther north, less frontal convergence
and a slightly more pronounced mid-level cap have suppressed
convective attempts over much of the Chicago metro. More notably,
out ahead of the front, a subtle axis of confluence has allowed
for a slightly greater coverage of showers to overspread areas
south of the Kankakee River Valley. Down there, latest RAP
mesoanalysis and recent HRRR/RAP soundings indicate that
equilibrium levels have risen above the 600 mb warm nose that is
suppressing convection farther to the north, allowing for some
deeper convective cores to sprout. With this deeper convection
growing above the -10C and even the -20C level, a couple of
isolated thunderstorms have developed, and it`s possible that
another thunderstorm or two could develop by the time this
activity exits our CWA to the south within the next couple of
hours. Given the presence of around 1000 J/kg of DCAPE where this
activity is located, there could be some gusty winds that occur
with the more organized storms, but the lack of stronger low- to
mid-level flow, the presence of the 600 mb "CAPE robber", and
subpar lapse rates above 600 mb will preclude a more organized
damaging wind threat. Otherwise, a rip current threat continues at
southern Lake Michigan beaches into tonight as high waves build
up in the wake of the aforementioned front.

Conditions are expected to remain dry tonight into Thursday through
most or all of our CWA as high pressure nestles into the region.
However, it should still be noted that an axis of warm air
advection-driven precipitation may materialize somewhere along
the central Mississippi River Valley Thursday morning. While it
can`t be ruled out that this activity clips or even crosses the
southwest CWA border, current indications in forecast guidance are
that this will remain west of our forecast area where the better
forcing for ascent will be while instability and moisture becoming
increasingly absent with eastward extent should keep our CWA
bereft of any precipitation through at least Thursday evening.
Thursday`s highs look to be in the low-mid 80s across much of our
CWA, though temperatures will only peak in the 70s closer to the
lakeshore as onshore flow prevails all day. An incoming shortwave
could then allow for showers and possibly a few storms to spread
into our CWA during the overnight hours into early Friday morning,
though it`s possible that this activity remains to our west through
this time and doesn`t arrive until later in the day on Friday.
Accordingly, the best chances for precipitation through daybreak
Friday are currently concentrated across the western half of our
CWA.

Ogorek

.LONG TERM...
Issued at 245 PM CDT Wed Jul 13 2022

Friday through Wednesday...

Primary forecast concern is precip chances Friday through Sunday.

Models are in fair agreement with a wave moving southeast across
the area on Friday, bringing the chance for rain to at least part
of the area. Guidance qpf values suggest the potential for over
an inch of rain, perhaps most likely across the north or northeast
cwa with precipitable water values into the 1.5 to 2 inch range.
Despite still some uncertainty regarding the best placement, given
the current trends, bumped pops up to the likely range for much
of the central and northern cwa Friday. Best timing may be
centered more on the mid/late morning into early afternoon. Also
increased sky cover and if more precip/clouds do materialize, its
possible high temps may only reach mid/upper 70s.

The upper ridge tries to make a push into the area Friday night
into Saturday morning and this may allow for an overall dry night
but confidence is low and chance pops are needed. Chance pops also
needed for Saturday. While there doesn`t appear to be much in the
way of forcing on Saturday, at least isolated afternoon/evening
activity is possible, perhaps mainly across the northwest cwa.
Though the GFS is faster with the next system to move across the
area on Sunday, which looks to be the next better chance for
convection across the area. Timing uncertain from this distance
and could be anywhere from Saturday night through Sunday night. As
this system shifts east by Sunday night/Monday morning, early
next week may end up being mainly dry. cms

.AVIATION...
For the 00Z TAFs...
Issued at 634 PM CDT Wed Jul 13 2022

Only item of note:

* Timing of wind shift back to northeast on Thursday

Steady northeast winds will decrease then shift to north-northwest
later tonight near the lake due to a land breeze. Winds west of to
at times due north will then flop over to north-northeast then
northeast on Thursday morning. Direction should then go farther
east due to lake influence at ORD and MDW Thursday afternoon.
There`s some uncertainty on the exact timing of the shift to a
north-northeast direction at ORD and MDW, though maintained 14z
timing for now. It`s possible the shift is a bit delayed. Also,
speeds should generally be below 10 kt Thursday morning and then
more frequently be near or around 10 kt during the afternoon once
lake influence kicks in. Winds will be solidly below 10 kt at
sites farther inland. Otherwise expect VFR conditions through the
period.

Castro

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement...ILZ006-ILZ103-ILZ104 until 3 AM
Thursday.

IN...Beach Hazards Statement...INZ001-INZ002 until 3 AM Thursday.

LM...None.
&&

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Area Forecast Discussion

National Weather Service Reno NV

133 PM PDT Wed Jul 13 2022

.SYNOPSIS...

Temperatures remain above average into early next week, with highs
near the century mark for the lower elevations of western Nevada.
Mainly dry conditions with breezy afternoons are expected today
and Thursday, with isolated thunderstorms again Thursday through
this weekend.

.SHORT TERM...Through Early Friday Morning...

* An upper level trough approaches the west coast today, bringing
increased dry southwesterly flow to our area. Thunderstorm
chances are nil this afternoon with much more stable conditions
favored. We`ll see an enhanced zephyr each afternoon and evening
through Thursday with gusts on the order of 25-35 mph. These
afternoon and evening breezes diminish somewhat (gusts 25-30
mph) into the weekend as the height gradient relaxes across
western Nevada as the ridge over the southwestern US builds
northward into our area.

* Thursday afternoon and evening, we`ll see some cumulus buildups
with around a 10-20% chance for thunderstorms across southern
Mono and Mineral counties. HREF thunder probabilities and HRRR
lightning density continue to hint at this. Both of these tools
have performed very well recently, with the HRRR nearly
resolving the location of lightning yesterday. Any thunderstorms
that form will be capable of producing cloud-to-ground lightning
outside of cores along with strong outflows, which will create
concerns with regard to fire weather. For more information,
please visit the fire weather discussion below.

* Smoke from the actively burning Washburn fire in Yosemite NP will
spread across a smaller area, mainly across northern-central
Mono, southern Lyon, and northern/western Mineral counties
through at least Friday morning as long as the fire burns
actively. Afternoon mixing will allow particulate matter to fall
into the boundary layer, impacting air quality in these areas.
We`ll continue to see haze across portions of western Nevada and
the Sierra south of I-80.

* Temperatures cool but remain above average into Thursday, with
highs across the Sierra expected to be in the mid-to-upper 80s and
upper 90s across the lower elevations. Lower valleys such as
Lovelock and Fallon will see another chance at breaking through
the century mark this afternoon.

-Johnston

.LONG TERM...Friday Onward...

* Southwest flow will prevail into next week with the Four Corners
high remaining in place and broad troughing offshore. Main
forecast issue will be how substantial and how far north moisture
coming around the west side of that high will get.

* The Eastern Sierra and areas of Nevada south of Highway 50 are
likely to see almost daily chances of t-storms Friday into early
next week, based on ECMWF ensemble guidance. NBM indicating a 1 in
4 to 1 in 5 chance of storms each afternoon-evening. TBD on storm
character but precipitable waters do get into that sweet spot of
0.6 to 0.8" that would yield wetting rains depending on storm
motions. New fire starts outside of storm cores are possible.

* Further north into Tahoe, Reno, and I-80 communities t-storm risk
is more uncertain. Ensemble guidance is more 50/50 on whether we`d
have enough moisture but it doesn`t take much when coupled with
terrain heating and zephyr convergence zones. So at this point a
10-20% chance each day seems reasonable. Storms in this area could
be drier so a few new fire starts and strong outflow winds are
possible. Up into NE California the airmass seems decidedly drier
so t-storm coverage likely to be much more isolated, but can`t
entirely be ruled out especially in the Lassen convergence zone
ENE of Lassen Peak.

* Temperatures will start off about 5 degrees above normal Friday-
Saturday. While well shy of records, Heat Risk levels do rise into
the moderate category meaning sensitive groups and those outdoors
for extended periods should take precautions. As we head into next
week, temperatures in the NBM guidance exhibit a gradual decline
to near or even slightly blow normal as that Four Corners ridge
becomes a little less robust in ensemble means. Given the gradual
nature of the decrease, winds will still remain typical for July
with zephyr breezes of 20-30 mph each afternoon for most areas.

-Chris

.AVIATION...

* Typical mid-summer weather pattern setting up today and Thursday
with daily W/SW zephyr breezes gusting to around 25 knots. Smoke
from the fire near Yosemite will primarily impact areas around
Bridgeport (O57) and Hawthorne (HTH) with occasional MVFR
visibilities and terrain obscuration, but some haze is possible at
times even northward to around TVL and MEV. The fire has not
produced a ton of smoke today so far, so the HRRR smoke may be
over estimating things in recent runs.

* Buildups and a few t-storms are back in the forecast starting
Thursday afternoon as moisture creeps around the west side of the
Four Corners high. Latest HREF guidance shows about a 10-20%
chance of storms from near MMH to HTH between 23z/Thurs-3z/Fri,
and possibly a rouge cell as far north as Bridgeport and
Yerington. Strong outflow winds to 40 knots, blowing dust, and
brief MVFR conditions are the most likely impact. Storms will
likely increase in coverage and northward extent Friday into the
weekend.

-Chris

.FIRE WEATHER...

Winds/RH:

* Dry southwesterly flow returns today with an enhanced zephyr
breeze (gusts up to 35 mph) expected this afternoon and Thursday
afternoon. A more typical afternoon southwest-west zephyr breeze
returns Friday into the weekend, with gusts 25-30 mph. Minimum RHs
will be in the lower teens through the weekend. Overnight RH
recoveries will be mediocre, with 25-35% across western Nevada and
30-45% across the Sierra.

Thunderstorm chances Thursday through the weekend:

* There will be a slight chance of showers and thunderstorms
(around 10-20%) across southern Mono and Mineral counties
Thursday afternoon. Friday afternoon and evening, we will see
increased thunderstorm chances (15-20%) over much of southern
Mono County, the southern Sierra Front, and southern Mineral
County. Saturday and Sunday, we`ll see chances increase (15-25%)
northward across southern Mono County, the central and southern
Sierra Front, and southern Churchill and Mineral counties.

* New fire starts outside of storm cores are possible each day
Thursday through the weekend. Any thunderstorms that form
Thursday will be of the dry variety due to fast storm motions
along with significantly deep inverted-v profiles capable of
producing wind gusts higher than 45 mph. Friday into the
weekend, deep inverted-v profiles and the potential for strong
outflow winds 45+ mph will persist; however, storm motions slow
significantly to around 5-15 mph, making any thunderstorms that
form each afternoon and evening to be more of a hybrid variety.

-Johnston

.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&

For more information from the National Weather Service visit...
http://weather.gov/reno