Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 06/10/22
Area Forecast Discussion
National Weather Service New Orleans LA
326 PM CDT Thu Jun 9 2022
.SHORT TERM...
Several areas of focus in the short-term, beginning with what`s
ongoing right outside our window this afternoon. Recent KLIX radar
trends illustrate developing cellular convection draped across the
northern half of the CWA. This convection resides along a subtle
convergent axis which, combined with building MLCAPE and sfc
temperatures surpassing convective T has led to this development.
Going through the rest of the late afternoon and evening, pre-storm
environmental conditions remain supportive for a few locally strong
thunderstorms, especially given ~3500J/kg MLCAPE and the subtle
dynamic forcing available. However, widespread severe weather
remains low as mid-level temperatures remain unchanged within the -
7C range, reducing hail growth CAPE. Additionally, recent ACARS
soundings from MSY illustrate why DCAPE remains relatively low (in
the 900J/kg range) with a rather moist low-level thermal profile
even following PBL mixing. Still, can`t rule out a few stronger sub-
severe wind gusts to around 40mph which will be the main concern
today, as well as dangerous lightning.
Recent 18Z HRRR guidance does try to keep convection ongoing this
evening given an abundant unstable environment coinciding with the
southward sagging convergence axis. Very possible it could drape
south of the I-10/12 corridor to around sunset or after, especially
given these storms currently becoming cold pool dominant, now
causing a southward moving outflow boundary to press out.
Thereafter, activity should transition into mainly marine or
nearshore areas later tonightgiven the residual convergence axis
tapping into the marine nocturnal environment. Focus here going into
tonight and daybreak if convection can hang around will be weak
waterspouts.
Going into tomorrow, confidence and focus for severe weather does
increase but first, will take a step back and talk about the overall
synoptic environment and its relation to recent CAM trends. As we
know, we remain largely under the influence of quasi-NW flow aloft
along the eastern periphery of a southern US ridge axis. But going
into early tomorrow, the ridge begins to retrograde slightly into
the desert Southwest, aiding in subtle height falls across our
region. Meanwhile upstream over the central US, embedded mid-level
impulses will lead to convective initiation this afternoon and
tonight, with likely convective complex evolution into a MCS riding
southeast within progressive NW flow. HRRR trends have been
consistent on the idea that a long-tracked MCS will enter our CWA
Friday afternoon thru the evening hours. Given noticeable H3
divergence, H7 to H5 jet influx and supportive PVA makes this a
plausible solution, especially given the weakness in upper-level
heights helping to pave a "corridor" or road for MCS propagation.
The pre-storm environment per CAM soundings illustrates modest
thermal modification, largely colder H5 temperatures in the -9 to -
11C range and steeper lapse rates approaching 6.5C/km which in turn
yields larger hail growth CAPE. Will with better confidence mention
the risk for severe weather appears greater, with the main risks
being damaging straight line winds around or > than 60mph, large
hail and can`t not mention intense rainfall rates leading to
localized flooding (given 1.8-2" PW`s) but hoping this complex will
remain progressive enough to alleviate widespread flooding concerns.
Glancing at HREF >40dBZ paintball plots paints a telling picture,
showing high confidence of an MCS but placement is not as confident,
likely caused by uncertainty on location of CI upstream forecast for
later today. Strongly believe once upstream convection becomes
better organized then initialized into future CAM runs, we`ll see an
alignment of better timing and strength. But, given confidence among
short-range guidance, did decide to increase PoP`s in the FRI 18Z-
SAT 03Z time frame to follow the southward position of the complex.
This complex is quickly out of here Friday night, but with some
lingering convection possible as subtle H5 PVA/impulses ride along
the NW flow aloft. Question remains how worked over we become from
the earlier complex with lingering widespread CINH/subsidence if we
can overturn enough, but timing is not going to be helpful being
overnight. But, if dynamics can offset and we can recover enough,
upscale growth of scattered convection could be possible through the
night. Impulses may continue to ride the flow during the day on
Saturday, with no major adjustments for PoP`s needed given greater
coverage potential for eastern areas. The thermal profile aloft is
somewhat similar glancing at recent NAM runs, perhaps a slight bit
warmer aloft which will lead to the possibility of a locally strong
storm or two.
.LONG TERM...(Sunday through Wednesday)
The upper ridge axis will begin to shift eastward on Sunday,
marking a transition to another less active period of weather.
Whatever is left of the lingering surface boundary could serve as
a focus for a few isolated to widely scattered showers Sunday
afternoon, but in general, subsidence aloft associated with the
upper ridge will suppress convection. Am carrying generally slight
chance POPs across roughly near the I-10 and I-12 corridors.
The high continues to shift eastward during the first half of the
work week, and really begins to amplify and strengthen by Tuesday
as an upper trough digs into the southwestern CONUS. As the high
strengthens, convection will basically shut off with the exception
of a few rogue showers/storms each afternoon. Any showers or
storms that do manage to develop would likely do so along a sea
breeze boundary where lift is enhanced, but even then, am only
carrying "silent 10" POPs Monday through Wednesday.
A lack of cloud cover and showers/storms will allow afternoon
temperatures to rise into the mid 90s by mid week. With dewpoints
forecast in the mid to even upper 70s, afternoon heat index values
will easily cross the century mark, and may be flirting with heat
advisory criteria by mid week. Will need to monitor trends as the
time period gets closer.
&&
.AVIATION...(Valid through 00z Saturday)
Largely VFR conditions through the cycle. Some convection will
fire (has started already along a front in So Miss), which may
impact those terminals shortly. With the more ISO nature, kept
VCs respectively for now, but a short fused TEMPO may be possible
for terminals east of the Lake early this afternoon. Another
round of convection will be possible late in the cycle. Again used
VCs for some and PROB30 for MCB. Otherwise, winds should remain
on the light and variable side outside of convection.
&&
.MARINE...
Local waters will remain on the periphery of a surface high
centered over the eastern Gulf through the period. This will keep
winds generally ranging between southerly and southwesterly
depending on location and small daily shifts in the ridge axis. A
weak boundary sinking toward the coast will support scattered
showers and storms at times tonight through the weekend, but
should completely dissipate by the start of the work week.
Expect winds to increase a bit overnight as is typical this time
of year, and have hoisted an exercise caution headline for most of
the open waters tonight as winds are now forecast in the 15-20kt
range. Will likely need exercise caution headlines tomorrow night
again and possibly continuing through the weekend as the pressure
gradient tightens slightly.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 71 91 72 91 / 10 60 20 50
BTR 74 93 74 93 / 20 60 10 40
ASD 74 93 75 93 / 30 60 20 50
MSY 78 92 78 94 / 30 60 10 40
GPT 75 92 75 91 / 40 50 30 50
PQL 73 92 74 92 / 40 50 30 60
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...None.
MS...None.
GM...None.
&&
$$
Short...KLG
Long/Marine...95/DM
Aviation...Frye
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
822 PM PDT Thu Jun 9 2022
.SYNOPSIS...09/138 PM.
High pressure will build over southern California through the rest
of this week bringing very warm and dry weather to interior
areas, peaking on Friday and Saturday. A few record high
temperatures will be possible. Coastal areas will be much cooler
with continued late night and morning clouds with patchy fog. A
cooling trend will start Sunday but another heat wave is expected
by the middle of next week.
&&
.SHORT TERM (THU-SUN)...09/759 PM.
***UPDATE***
Overall, a very quiet evening across the forecast district.
Current satellite and surface observations indicate some stratus
and fog hugging the beaches of Ventura and LA counties with mostly
clear skies elsewhere (due to some passing high clouds). AMDAR
soundings indicate marine inversion around 900 feet deep
currently. No significant winds are observed.
Forecast-wise, main issue overnight will be the marine layer
stratus/fog. Do not anticipate much, if any, deepening of the
marine inversion overnight. So, will anticipate any stratus/fog
to remain confined to the coastal plain south of Point Conception
and possibly some of the the lower coastal valleys. Given the
shallow nature of the inversion, dense fog could be an issue
overnight. At this time, will keep with the mention of patchy
dense fog overnight, but it could be widespread enough for an
advisory later tonight (and will brief the night shift on that
possibility). Other than this coastal stratus/fog, skies should
remain mostly clear overnight.
For the immediate short term, current forecast has good handle on
the situation. So, no significant updates are expected at this
time.
***From Previous Discussion***
After a cooler start to the day temperatures in most areas are
rebounding quickly as high pressure builds, gradients weaken, and
the marine layer depth lowers. Temperatures now trending warmer
in most areas, but especially in LA/Ventura Counties between 800
and 1500 ft elevation. Marine layer depth earlier this morning was
around 2000` but forecast soundings indicate this will be cut in
half by Friday morning and it looks like it`s already moving in
this direction. So as the night goes on there`s an increasing
chance of dense fog south of Pt Conception.
Given the current trends it looks like everything is on track for
an even hotter day Friday across inland areas. A shallow marine
layer and light onshore flow will moderate temps at the coast but
inland areas will heat up. Looking at 100+ in the warmest coastal
valleys (namely the western San Fernando Valley) as well as
interior SLO County and the Antelope Valley. Heat advisories and
warnings already in effect there and will be adding the Santa
Monica Mountains, mainly in the interior parts which won`t have
the maritime moderation. Broken high temperature records look
likely in Paso Robles Friday where the record high there is 105
and in the Antelope Valley (103). LA Valley records are at least
105 and likely out of reach for this event as models only showing
an 18% chance of highs over 105 in Woodland Hills.
Another hot day expected Saturday, though slightly cooler than
Friday as onshore flow increases. Similar trend for Sunday with
the added factor of a trough approaching from the northwest, so
the marine layer will be deepening. Highs still above normal but
only by about 5 degrees or so.
.LONG TERM (MON-THU)...09/212 PM.
A weak trough and increasing onshore flow to the east will
continue the cooling trend into Monday with temps getting back to
near to just slightly above normal. At the same time northerly
gradients will be increasing as the trough approaches bringing a
return of gusty Sundowner winds to the Santa Ynez Range and
surrounding foothills and coastal areas.
After that ensembles do seem to be favoring another heat wave for
the middle of next week, starting Tuesday but peaking Wed/Thu with
highs similar or possibly even slightly warmer than the current
heat wave. While a few ensemble members show the heat reaching the
coastal areas, there doesn`t appear to be enough offshore flow to
overcome the typical sea breeze so while it will be warmer than
normal near the coast most of the significant heat should remain
inland. Current forecast high temperatures are likely a bit on the
low side but as confidence increases over the next few days expect
those to increase.
&&
.AVIATION...10/0030Z.
At 2318Z at KLAX, the marine layer was 1100 feet deep. The top of
the inversion was near 3100 feet with a temperature around 28 C.
High confidence in KPRB, KPMD, and KWJF TAFs.
Moderate confidence in KSBP TAF as there is a 20% chance of IFR
conds 08-16Z. There is a 20% chance of IFR/LIFR cigs at KVNY and
KBUR 07-16Z.
Low confidence in remainder of TAFs. Timing of flight cat changes
could be off by at least 3 hours. Cigs at KSMO, KLAX, and KOXR may
frequently scatter, reform, and/or bounce between low MVFR to
high IFR before 05Z. There is a 40% chance of conds only as low as
IFR at KCMA and KOXR. There is a 20% chance of LIFR conds at KSMO,
KLGB, and KLAX.
KLAX...Low confidence in TAF. Cigs will frequently scatter,
reform, and bounce between Bkn008-010 before 05Z. There is a 20%
of LIFR conditions after 08Z Friday. Timing of cigs scattering may
be off by +/- 3 hours. Good confidence that any east wind
component should remain less than 7 knots.
KBUR...There is a 20 percent chance of IFR/LIFR conditions after
07-16Z Friday.
&&
.MARINE...09/819 PM.
For the waters south through northwest of the Channel Islands and
along the Central Coast, gusty northwest winds and short-period
hazardous seas will slowly diminish some through tonight. The
poorest wind and sea conditions are expected to be focused across
the waters beyond 10 NM off the Central Coast and northwest of
the northern Channel Islands, thus a Gale Warning is in effect
until late tonight. There is a 30-40% chance of gale force wind
gusts for the same waters Friday and Saturday afternoon and
evening. Otherwise, Small Craft Advisory (SCA) level winds with
lingering short- period seas will likely linger into Friday and
Saturday. For the southern outer waters (zone PZZ676), a SCA is
in effect until late tonight. Then, winds and seas will likely
remain below SCA levels through Saturday morning.
Inside the southern California bight, winds and seas will largely
remain below SCA levels levels through Saturday.
Winds will likely strengthen over the weekend and marine weather
conditions will likely deteriorate. There is a moderate chance of
GALES with short-period hazardous seas for the outer waters
between Sunday and Monday night.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory in effect from 10 AM Friday to 10 PM PDT
Saturday for zones 53-54-345-353. (See LAXNPWLOX).
Excessive Heat Warning in effect from 10 AM Friday to 10 PM
PDT Saturday for zones 59-343-344. (See LAXNPWLOX).
Heat Advisory in effect from 10 AM Friday to 8 PM PDT
Saturday for zones 88-356>359-363-547-548. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Friday for
zones 645-676. (See LAXMWWLOX).
Gale Warning in effect until 3 AM PDT Friday for zones
670-673. (See LAXMWWLOX).
&&
$$
PUBLIC...MW
AVIATION...Lund
MARINE...Lund/Sweet
SYNOPSIS...MW
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox
Area Forecast Discussion
National Weather Service Phoenix AZ
416 PM MST Thu Jun 9 2022
.UPDATE...
Updated 00Z Aviation
&&
.SYNOPSIS...
The first excessive heat event of the season is now
upon us as high pressure strengthens across the region before
reaching its peak intensity Friday through Sunday. High temperatures
this afternoon are expected to top out at around 110 degrees with
the hottest days then occurring Friday through Sunday with
widespread readings of 110 to 115 degrees across the lower deserts.
Overall dry conditions will continue to prevail, but isolated
showers and thunderstorms producing little rainfall will be possible
across the eastern Arizona high terrain through at least Friday. The
heat should briefly lessen early next week with temperatures falling
back to near normal readings.
&&
.DISCUSSION...
The area`s first excessive heat event of the season continues to
be the main topic over the next few days, although a modest
moisture increase into our region today into the early weekend
will also bring slight chances for some high based showers and dry
lightning thunderstorms, mostly over the E and SE AZ high
terrain. Early afternoon water vapor imagery shows a weak upper
level low pressure circulation and vort max now moving slowly W-NW
just off of the Baja Coast and an extension vort lobe disturbance
pushing north and advecting mid and upper level moisture into the
southern half of AZ.
For today, temperatures will continue to warm another couple
degrees over yesterday with lower desert highs topping out right
around 110 degrees. Models agree on the upper low drifting to the
W-NW, although the circulation has brought a vort lobe northward
into S-SE-E AZ this afternoon. ACARS soundings show BL moisture
remains very dry even though PW is increasing and forecast to
reach near 1". With moderate moisture advection aloft focused
between 13-20KFt MSL, forecast model soundings maintain a dry
subcloud layer and inverted V profile with elevated DCAPE near
1,700-1,800 by Fri evening E of Phoenix.
HREF members are in good agreement on showing isolated to
scattered potential convection focused mainly across far SE-E
Arizona including the White Mtns and E Gila County. This is the
same area that early afternoon radar showed some modest convection
popping up. Other than that, isolated virga signatures were also
noted mostly south of Phoenix. Rainfall potential will be very
meager (less than 0.10") due to the dry sub-cloud layer/BL. Fri
should be a similar day for convection compared to today as some
models show PW remaining relatively elevated near 1" with HREF
members also remaining in agreement on the mostly distant, high
terrain dry storm potential.
By Sat, the upper level low will exit the region allowing the
ridge to continue to further strengthen over our region. There
should be enough lingering moisture on Sat for another round of
isolated afternoon convection across far eastern Arizona, but
with even less moisture activity is likely to be east of Gila
County.
Friday through Sunday are set to be our hottest days so far this
summer as the upper level ridge fully sets up over our region and
500mb heights rise to around 592-594 dam, or into the 97-99%
percentile of climatology for the period. NBM temperature guidance
remains consistent showing excessive heat conditions lasting
through the weekend with daytime highs easily above 110 degrees
across the lower deserts. The hottest day still looks to fall on
Sat where highs of 112-116 degrees are forecast. Overnight lows
will also be quite uncomfortable with most lower desert locations
staying above 80 degrees to as warm as the upper 80s in central
Phoenix. High to Very High HeatRisk will be prevalent across the
area through Sunday. In addition record highs will be seriously
challenged Fri through Sun. For the warmest day on Sat, there is
a 50% NBM chance of tieing the Phoenix record high of 114
degrees..
Some relief from the excessive heat will be seen by early next
week as a Pacific trough dives southeastward over the NW U.S. on
Sun before reaching the Great Basin and at least into northern
portions of our region on Mon. Noticeable cooling will spread
across our region starting Mon, lowering high temperatures mostly
between 105-108 degrees, or back into the Moderate HeatRisk
category. The approaching trough will also lead to an increase in
winds as afternoon gusts of 20-30 mph look likely for Sunday and
Monday.
After the brief dip in temperatures early next week due to the
passing trough to our north, model ensembles favor the ridge
building back over our region from the southwest by next
Wednesday. This should lead to another warm up with NBM forecast
highs back to around 110 degrees for the middle to latter part of
next week.
Ensembles then mostly agree on showing this ridge eventually
shifting more over the Southern Plains, potentially resulting in
deep southerly flow developing across our region. This set up very
well could result in significant moisture advecting out of Mexico
into our region at some point late next week into the following
weekend. Both the EPS and GEFS show this potential influx of
moisture, with remarkably high GEFS forecast PWAT anomalies from
June 17-20 over the Southwestern U.S., upwards of 200-300% above
normals. Given the third week of June is normally quite dry over
the Desert Southwest, any amount of moisture would result in
higher than normal, but this seems to be significant and could
result in a few days of showers and thunderstorms across portions
of the region, even over the lower deserts.
&&
.AVIATION...Updated at 2316Z.
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Little to no weather concerns will exist through Friday afternoon
under occasional periods of mid/high cloud decks. Current breezy
westerly winds to persist quite a while, with the overnight switch
to easterly likely occurring later than usual (well after
midnight/towards morning). An occasional gust near 20kt will be
possible thru the early evening. Looking very unlikely at this point
that any outflows from distant T-storms over White mtns/far SE AZ
will make it anywhere close to the Phoenix area tonight. After a
very short period of easterly winds Friday morning, a quick switch
to westerly is expected (mid-late morning) with these westerly winds
becoming rather gusty Friday afternoon. Westerly winds will likely
persist well into Friday night as well.
Southeast California/Southwest Arizona including KIPL and KBLH:
Very little weather issues will exist through Friday evening under just
some passing high clouds. While some variability in wind directions
during the late night/early morning will not be uncommon, SE
directions should be most prevalent at KIPL and southerly at KBLH
through the period. A few gusts near/just over 20kt will be likely, and most
preferred at KBLH this afternoon and again on Friday afternoon.
&&
.FIRE WEATHER...
Very hot temperatures and slight chances for dry thunderstorms
will be the main concern through at least Sat. A slight chance of
isolated showers and dry lightning thunderstorms will be possible
across Gila County every afternoon through Sat, potentially
resulting in new fire starts. Expect highs around 110 degrees
today across the lower deserts and 110-115 degrees on Fri and Sat.
Afternoon Min RHs will mostly range between 8-15% for most areas,
while winds will overall be fairly light, aside from upslope
westerly afternoon gusts to around 20 mph through Sat. Slightly
stronger winds are expected on Sun and Mon afternoons with gusts
upwards of 25 mph, likely increasing the fire danger threat.
Moisture levels will continue to be a bit higher than typical for
this time of year, but afternoon MinRHs will still mostly fall to
between 7-10% over the majority of the area through the period.
Temps early next week will cool down some, but remain at least a
few degrees above normal, with warmer temperatures returning by
the 2nd half of next week.
&&
.CLIMATE...
Daily Record Temperatures:
Phoenix Yuma El Centro
Thursday: 114 (1985) 116 (1955) 114 (1973)
Friday: 111 (1978) 115 (1910) 112 (1973)
Saturday: 114 (1918) 115 (1956) 113 (1939)
Sunday: 112 (2019) 117 (1956) 115 (2019)
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Excessive Heat Warning until 8 PM MST Sunday for AZZ530>556-
559>562.
CA...Excessive Heat Warning until 8 PM PDT Sunday for CAZ561>570.
&&
$$
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DISCUSSION...Sawtelle/Kuhlman
AVIATION...Percha/18
FIRE WEATHER...Sawtelle
CLIMATE...Kuhlman
Area Forecast Discussion
National Weather Service Great Falls MT
800 PM MDT Thu Jun 9 2022
.SYNOPSIS...
As warm air continues to push in from the west, expect mainly dry
and breezy conditions to continue across the area through Friday.
Moisture will begin to push into Southwestern Montana on Saturday,
which will gradually spread northward and eastward early next
week.
&&
.UPDATE...
Overnight, generally light winds are forecast; however, as we
progress into tomorrow, expect wind speeds/gusts to increase.
Widespread non-warning criteria gusty winds are forecast. Current
weather forecast is spot on; therefore, no updates are made, at this
time.
- Fogleman
&&
.DISCUSSION...
Warm air has made its arrival known across North-Central and
Southwestern Montana this afternoon, with most areas reaching into
the 70s this afternoon under mostly sunny skies. Some breezy
winds accompanied the warmer air, with some areas seeing some wind
gusts to around 20 mph or so, mostly across the plains. The
mostly clear and warm conditions should persist through the first
part of Saturday area wide, as westerly winds continue to bring
warmth to the area.
Our weather will turn more active this weekend, as the first in a
series of weather systems associated with upper level troughing
push into the area. Light rain is expected across portions of
Southwestern Montana with this system, but overall this first
system should not cause much of an impact across the area other
than some light beneficial rainfall. The second, more potent (and
potentially impactful) weather system will push into Southwestern
Montana on Sunday, and will push into North-Central Montana by
Monday morning. Precipitation amounts are still somewhat uncertain
at this time, but there are indications that some areas across
the southwestern mountains (particularly south of Bozeman) could
see over an inch of rainfall. While an inch of rainfall will be
beneficial for most, there is some concern that this inch of
rainfall will combine with a melting snowpack to produce some
rises on rivers across Southwestern Montana. Rises on rivers will
need to be monitored very closely, as there remains some chance
that a few areas may see some minor river flooding. Across the
plains, even more uncertainty exists, though today`s model runs
are a bit wetter than what they were at this time yesterday.
Hopefully this trend continues, as we are closing in on the end of
our climatological wet season.
In the wake of this system, high pressure will build into the area
aloft and at the surface, bringing warmer temperatures and dry
weather to the area. Ludwig
&&
.AVIATION...
556 PM MDT Thu Jun 9 2022 (10/00Z TAF period)
Expect VFR conditions at all airfields throughout this TAF period.
Areas of mountain obscuration are forecast. The greatest impact to
aviation operations is wind speed/gust. Generally, after 10/13Z,
wind speed/gusts begin to increase, especially impacting light
aircraft near mountain and through mountain passes/valleys where
winds may become funneled.
- Fogleman
Refer to weather.gov/zlc for more detailed regional aviation weather
and hazard information.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 57 78 55 76 / 10 10 20 30
CTB 56 73 51 72 / 20 10 20 20
HLN 58 79 58 76 / 10 20 30 60
BZN 51 80 53 75 / 0 10 10 50
WYS 42 74 45 71 / 0 10 0 40
DLN 51 78 52 74 / 0 10 10 50
HVR 58 81 56 80 / 10 10 10 10
LWT 52 78 53 73 / 10 20 30 60
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
http://www.weather.gov/greatfalls