Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/10/24
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
923 PM CDT Tue Jul 9 2024
.KEY MESSAGES...
- Chances for thundershowers overnight (20-60%) mainly east of the
Missouri River.
- Hazy conditions continue this evening through Wednesday night
as north- northwest flow is bringing in periodic waves of smoke
from Canadian wildfires. Much of this is expected to remain
aloft, with little to no reductions in visibility at the
surface.
- High confidence in hot and muggy conditions for the extended
period. High temperatures will be in the 90s (5-10 degrees above
average) Friday through Sunday along with dewpoints in the mid
to upper 60s. This combination will result in "feels like"
temperatures ranging in the mid and upper 90s with a few spots
to 100F each afternoon.
&&
.UPDATE...
Issued at 920 PM CDT Tue Jul 9 2024
Still some thunderstorm activity going on east of the Missouri
River, with more approaching the northeastern CWA from North
Dakota. Have seen some large hail and gusty winds with a few of
the storms. No changes made to winds or temperatures at this time.
&&
.SHORT TERM /THIS EVENING THROUGH WEDNESDAY NIGHT/...
Issued at 331 PM CDT Tue Jul 9 2024
As shown by several CAMs earlier, isolated showers have developed
over far eastern SD into western MN. Air mass out that way is
characterized by around 1500 J/KG SBCAPE, but not much to speak of
in terms of shear. Mid-level lapse rates are also rather poor in
terms of supporting any robust convection. So, the trend through
this evening will be for these isolated/widely scattered showers to
persist, and perhaps even persist into the overnight a bit as there
is a vort noticeable on satellite imagery moving south across
central ND. Some CAMs keep additional development going through 06Z
right in the vicinity of the vort center. Did convey this thinking
through PoPs, with some higher 40-60% values in the vicinity of the
expected vort path.
Otherwise, other issue to watch will be the smoke moving southward
across the region from Canadian wildfires. HRRR/RAP smoke products
suggest mainly smoke aloft being the issue here as concentrations
increase towards morning. In fact, there is some noted increase in
near-surface smoke potential by 12Z Wed in the HRRR output.
Overnight shift may want to consider adding smoke to the wx grids
if, in fact, vsby start to drop across the region towards morning.
Confidence wasn`t high enough that these modest smoke concentration
increases would be enough to affect vsby, so mention of it was left
out for the time being. Although, with the expected increases in
smoke aloft, did bump up the sky grids just a bit.
Any afternoon pop-up showers on Wednesday look to be confined to
around the I-29 corridor and points east, which is where current
PoPs are evident in the forecast. Again, severe parameters are
lacking, so not expecting severe storms at this time. As for
temperatures, fairly similar to today, with highs rising into the
80s to around 90 degrees over central SD.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 331 PM CDT Tue Jul 9 2024
Main highlight for the long term will be the increase in
temperatures/dewpoints across the CWA for the end of the week and
especially this weekend. Clusters indicate the 500mb ridge`s axis
over the Rockies with the mid level high continuing over the
southwestern US for Thursday. This pattern continues Friday through
the weekend (the ridge becoming more broad) with the mid level high
expanding over much of the Rockies and into the western Plains where
it starts to de-amplify early next week. Across Canada, several
shortwaves will push west to east, disrupting the northern edge of
the ridge`s axis. It does become more amplified again over western
Canada by early next week, shifting east through the midweek.
High confidence exists on Friday through Sunday being the hottest
period with Sunday the hottest day of the week. Mean ensemble 850mb
temps are forecasted to range between 22-26C Friday afternoon, 23-
27C Saturday afternoon, and up to 29C Sunday! To put this in
perspective this is above the 90% average, per KABR sounding climo
page. NAEFS indicates the 850mb temps range from 90-97.5% above
average and 700mb temps 97.5-99.5% above climo average by 00Z
Monday. So daytime heating and mixing and a higher/stronger sun
angle will allow surface temps to warm up quickly into the 80s and
90s for the end of the week. By Saturday, temps over the entire CWA
will be in the 90s to even some lower 100 readings, mainly in south
central SD on Sunday. At this time, prob of 100 degrees for Sunday
ranges from 30-50% over south central SD. EFI has a value of 0.9 for
for Max T this day, however, NDFD Forecast Records do not show
anything for the CWA in terms of MaxT records for now. The overall
spread between the NBM 25-75th is pretty thin, ranging from 3-5
degrees. Little bit more of a spread on Sunday with a max difference
of 5-8 degrees over north to central SD, with the spread increasing
further out in time next week over the CWA.
Not only will it be hot, dewpoint values will range in the mid to
upper 60s Friday into this weekend making it muggy! This will put
heat index readings across the CWA well into 90s with even lower
100s, especially across central SD. So NWS Heat Risk does highlight
a major risk for of heat related impacts for Saturday across our
northern and northeastern CWA and more widespread for Sunday. The
good news is a cold front is forecasted to push through early next
week with cooler air behind it that will move in from the northwest
bringing relief.
Convection wise, NBM has occasional slight pops chances (15-20%)
over the CWA Friday evening into early next week associated with
these Canadian shortwaves (ridge runners!). CSU does highlight
low chances (15% and under) of severe probabilities Days 4-7.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 624 PM CDT Tue Jul 9 2024
Terminals KABR,KATY,KPIR,KMBG
For the most part, VFR conditions will prevail across the area
tonight and through the day Tuesday. There will be a few
thunderstorms around this evening. Brief periods of MVFR vsbys are
possible with the thunderstorms. Smoke aloft will affect the
region late tonight and Tuesday.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...Parkin
SHORT TERM...TMT
LONG TERM...MMM
AVIATION...Parkin
Area Forecast Discussion
National Weather Service Amarillo TX
618 PM CDT Tue Jul 9 2024
...New UPDATE, AVIATION...
.UPDATE...
Issued at 618 PM CDT Tue Jul 9 2024
Showers and storms continue to move slowly east/southeast across
the higher terrain into the plains of New Mexico. Shower/storm
activity is a bit more widespread than hi-res model guidance has
suggested throughout the day today. Have slightly modified PoPs
based on radar trends and expected evolution of the convection
through the evening hours. Otherwise the rest of the forecast
through tonight remains on track.
Muscha
&&
.SHORT TERM ...
(This evening through Wednesday night)
Issued at 204 PM CDT Tue Jul 9 2024
What remains of today as well as tomorrow could be our best
chances for showers and thunderstorms for this week mostly thanks
to the still present northwesterly flow seen in the upper-levels.
This flow will aid in moving any convection started off the
southern Rockies over the Western Panhandles for this evening and
Wednesday. Despite the decent northwesterly flow, however, chances
are still rather limited with latest CAMs seeing best chances for
isolated storms until late this evening. Severe potential is not
that great either, with most CAMs seeing less than 100o J/kg of
MLCAPE. Still a severe wind gust can not be fully ruled out,
especially if the inverted V soundings the RAP is presenting comes
to fruition.
Rather, the better chances may follow Wednesday afternoon with
models seeing a short-wave move through and act as a boundary for
the day. As it stands latest CAMs are seeing the potential for
showers around and south of I-40 with guidance seeing POPs around
20 to 30% for the afternoon and evening. Severe potential is
better in terms of MLCAPE with most models seeing 1000 to 2000
J/kg present across I-40 and south. However, the shear is not the
greatest with only a handful of models seeing effective bulk shear
near 20kt. Once again the main threat may be more on the wind
side of things with the sounding and DCAPE suggest a severe wind
gust can not be ruled out from a collapsing thunderstorm.
Otherwise, drier conditions look to follow in the overnight as
models see the stronger upper-level high begin to move in. As for
temperatures, look for them to be on the rise today and tomorrow
with most locations returning to the low to mid 90s both
afternoons.
Scoleri
&&
.LONG TERM ...
(Thursday through next Monday)
Issued at 204 PM CDT Tue Jul 9 2024
Warm and dry will likely be the main themes clear into the next
week as many models see the strong 500mb high pressure system
shift east and place the Panhandles underneath it clear through
Monday. This will cause the upper-level flow to shift to a more
northerly to near stagnate flow which will make it hard for
anything that develops off the western mountain ranges to move
through. The only exception may be Thursday, when flow could still
be strong enough in afternoon. However, confidence in such a
outcome is not high given that would require high dewpoints to
hold, which not many models are expecting. Otherwise, the main
issue for what remains of the week will be the continue rising
temperatures. As it stands, all locations will look to be in the
mid to upper 90s as early as Friday, with chances at triple digits
getting better as we head into the weekend.
Scoleri
&&
.AVIATION...
(00Z TAFS)
Issued at 618 PM CDT Tue Jul 9 2024
Showers/storms will be possible for KDHT at the beginning of this
TAF cycle. Storms may reach as far east as KAMA, but confidence is
not high enough to mention, will amend if storms look to move
closer to the terminal. Otherwise, winds will remain pretty light
around 10 kts or less during this TAF issuance. Outside of any
storms moving over the terminals, VFR conditions are expected at
the sites.
Muscha
&&
.PRELIMINARY POINT TEMPS/POPS...
Amarillo TX 65 94 64 94 / 20 30 20 10
Beaver OK 63 96 64 97 / 0 10 0 0
Boise City OK 59 91 60 93 / 20 10 0 0
Borger TX 67 99 67 100 / 10 20 10 10
Boys Ranch TX 64 95 64 96 / 30 30 20 10
Canyon TX 64 92 61 92 / 20 30 20 10
Clarendon TX 66 94 65 94 / 0 30 10 10
Dalhart TX 59 93 59 94 / 30 20 10 0
Guymon OK 61 94 61 97 / 10 10 0 0
Hereford TX 64 94 62 94 / 30 30 20 10
Lipscomb TX 65 96 65 98 / 10 20 10 0
Pampa TX 64 94 64 94 / 10 30 10 10
Shamrock TX 66 95 65 96 / 0 30 0 10
Wellington TX 67 96 66 97 / 0 20 10 10
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...None.
OK...None.
&&
$$
SHORT TERM...11
LONG TERM....11
AVIATION...05
Area Forecast Discussion
National Weather Service Bismarck ND
945 PM CDT Tue Jul 9 2024
.KEY MESSAGES...
- Smoky skies are expected through Wednesday, with some near-
surface smoke reducing visibility at times across central
North Dakota.
- Hot and humid conditions are expected Thursday through Sunday,
with highs mostly in the upper 80s to upper 90s.
- Low chances for showers and thunderstorms are in the forecast
at various times from Thursday evening through the weekend.
&&
.UPDATE...
Issued at 943 PM CDT Tue Jul 9 2024
The shower and thunderstorm activity has mostly ceased across
the area, with a few showers lingering around in far eastern
LaMoure and Dickey counties. The main update was just adjusting
the PoPs and sky cover to better reflect current trends.
Otherwise, the forecast remains on track.
.UPDATE...
Issued at 628 PM CDT Tue Jul 9 2024
As showers and thunderstorms continue across the James River
Valley, a few isolated showers may develop across the northwest
over the next few hours as well. A cluster of stronger storms
has since congealed into one cell and strengthened further,
which warranted a Severe Thunderstorm Warning in portions of
LaMoure, Logan, and Stutsman counties. Will continue to monitor
if any further development will be possible across this area,
but our current thinking is that this will likely be it in terms
of severe development. We also had a small cell with a few
lightning strikes pass near Williston, so our main change for
this update was adding in some PoPs to the northwest for the
next few hours. Diurnal cumulus in eastern Montana has also
begun to move into the area up there, so just slightly boosted
cloud coverage in that area as well. Otherwise, the forecast
remains mostly on track.
&&
.DISCUSSION...
Issued at 235 PM CDT Tue Jul 9 2024
The Northern Plains still remain in a cyclonic northwest flow
pattern this afternoon, though the upstream ridge over the Rockies
is beginning to nudge closer. A shortwave trough is crossing the
eastern half of the state from north to south this afternoon, and
there is evidence of a meso-low centered between Bismarck and Harvey
from visible satellite trends and the analyzed surface wind field.
These features could help spark a few more sustained showers and
thunderstorms over the James River Valley and areas adjacent to the
west through the evening. More sporadic afternoon convection driven
by diurnal heating under the cyclonic flow is possible elsewhere,
but coverage away from the meso-low is forecast to be lower. A few
CAMs have been simulating a couple of strong thunderstorms with
the shortwave/meso-low in the James River Valley. While SBCAPE
is already analyzed around 2000 J/kg and 0-6 km shear could
increase to near 30 kts, model soundings show a thermal
inversion around 600 mb that was sampled by the 12Z BIS RAOB
that could provide some inhibition. Additionally, RAP non-
supercell tornado (NST) parameter projections are once again
highlighting a funnel cloud risk over the James River Valley,
and though this potential could be lower than previous days
given the slight bump in deep layer shear, the meso- low could
supply locally enhanced surface vorticity. On Wednesday, flow
aloft will turn more northerly and transition to more of an
anticyclonic regime over broad surface ridging. This should
finally give us a break from any afternoon showers or storms.
Highs both this afternoon and Wednesday are forecast in the 80s,
closer to 80 in the Turtle Mountains area and closer to 90 in
the southwest.
Despite the subtle shift in the synoptic pattern, trajectories will
remain favorable for smoke from Canadian wildfires to spread over
the region through at least Wednesday. Forecast confidence is higher
in smoke aloft than at the surface, and concentrations of both
should be greater over central North Dakota compared to farther
west. Tonight there looks to be a potential for a repeat of a
smoke/fog combination reducing visibility to around 3 to 6 miles, as
was observed this morning.
For Thursday through Sunday, an expansive heat dome/upper level high
pressure over the mountain states will push its northeast periphery
into the Northern Plains. The main story for us over this time
period is above normal temperatures, with NBM forecast highs in the
upper 80s to upper 90s most of these days at most locations, and
approaching 100 degrees in the southwest. Forecast dewpoints are
also consistently in the 60s, expect in the southwest, and approach
70 in eastern parts of our forecast area at times. While this
combination of heat and humidity is not unusual for this time of
year and this part of the country, this will be our first multi-day
stretch this summer. People that are highly sensitive to heat and
those who must spend time outdoors will want to take extra
precautions.
During this period of anomalous warmth, the Northern Plains could
also be in a favorable track for ridge riding shortwaves embedded in
stronger upper jet flow. This would lead to an increased risk of
thunderstorms at times, with at least some potential for severe
weather given the stronger flow aloft and warm/moist boundary layer.
CSU machine learning guidance has been consistently painting low
severe probabilities over much of the state Friday through Sunday.
While forecast timing and to a greater extent spatial details of
convection remain low at this time range, the first potential is
consolidating on Thursday evening across the western half of the
state ahead of a lee surface trough and upstream mid level impulse,
although a capping inversion could play a role in suppressing
convective development and strength. It is interesting to note that
subsequent time periods with mentionable NBM PoPs are mostly during
the evening and overnight despite there being no strong model signal
for a persistent nocturnal low level jet.
Early next week, ensemble spread greatly increases on account of
uncertainties in the evolution of troughing digging into the Great
Lakes region. There is a distinct lowering in the NBM high
temperature distribution next week, but mean values are still near
mid-July averages of mid 80s.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 628 PM CDT Tue Jul 9 2024
VFR conditions are present across all terminals, and will likely
prevail through the TAF period. Some isolated storms have formed
in the James River Valley, which may briefly bring about reduced
visibilities at KJMS should any of them pass over the airport.
Given the uncertainty in exact location of storm development,
only vicinity thunderstorms have been added for the next 3
hours. Some showers may also be possible across the far
northwest, with vicinity showers at KXWA for the next 3 hours as
well. Reduced visibilities to MVFR conditions due to a
combination of fog and near surface smoke may occur across
central and eastern North Dakota early Wednesday morning,
affecting KBIS, KJMS, and KMOT. Winds will decrease to light and
variable over the next few hours, remaining this way through the
rest of the TAF period.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Besson
DISCUSSION...Hollan
AVIATION...Besson
Area Forecast Discussion
National Weather Service Buffalo NY
1018 PM EDT Tue Jul 9 2024
.SYNOPSIS...
Our stretch of fair dry weather will come crashing to an end later
tonight and Wednesday...as the remnants of Beryl will make its way
out of the Mid West. A soaking one to two inches of rain can be
expected in many areas by Thursday morning...with higher amounts
possible east of Lake Ontario and even moreso across the Adirondacks.
Along with tropical downpours on Wednesday...there will be the risk for
strong to severe thunderstorms...mainly across the western Southern
Tier and for portions of the Finger Lakes.
&&
.NEAR TERM /UNTIL 6 PM WEDNESDAY EVENING/...
...Significant Rains AND increased severe weather threat continues
from the Remnants of Beryl on Wednesday...
Late this evening, radar shows most of the showers have ended
across Western NY, with mainly rain-free conditions.
Conditions will significantly deteriorate during the course of
tonight though...as the remnants of Beryl over the Lower Ohio valley
will push northeast. A tropically enhanced warm front extending to the
east across Pennsylvania will approach our region in the process. A
modest 25 to 30kt low level jet impinging upon this boundary will
combine with forcing under the nose of an 80kt UL jet to lift a
deepening tropical airmass to generate increasingly widespread rain as
we progress through the overnight/wee hours Wednesday morning. PWAT
values will surge to 2.25" by daybreak...so some heavy rain will be
possible...particularly within any embedded thunderstorms. The focus of
the rain late tonight will be over the western counties with sites west
of the Finger Lakes most likely to experience the heavier downpours.
Wednesday will most certainly be the most unsettled day of the week...
as the center of whats left of Beryl will track across the far west end
of Lake Erie to southernmost Ontario. Meanwhile...the aforementioned
eastward extending warm front will gradually advance across our
forecast area. The deep tropical moisture will focus near and north of
the advancing warm front where widespread moderate to heavy rain is
expected. Daytime rainfall amounts are forecast to range from
around a half inch across the western Southern Tier to 1-1.5
inches most elsewhere. Embedded thunderstorm activity could
locally double that amount. The good news is that the threat for
excessive rains has diminished across the sloped terrain of the
Southern Tier...but on the flip side...the risk remains in
place for the more populated areas from Buffalo...Batavia and
Rochester to the Eastern Lake Ontario region. Six hour FFG
guidance for this particular area is in the vcnty of 2.25" and
this will limit the risk for widespread hydro concerns to some
extent. Rain will increase flow in most area tributaries, but
given recent dry weather and seasonably low current levels the
rises on larger rivers are likely to remain within bank.
However, localized heavy rains in this moist environment will
still have the potential to produce flash flooding or general
flooding. Updated WPC forecast clips Lewis county with a
moderate risk for excessive rainfall, leaving most of the
forecast area in a slight risk.
As for the potential for severe weather...the Storm Prediction
Center has outlined much of western New York within a slight
risk area. This aligns with the progression of the tropically
enhanced warm front where a notably enhanced amount of shear
will be present. Bulk shear values of 40-50 kts and veering low
level profiles will support supercells and a non-zero threat of
tornadoes...along with clusters that will include tropical rain
loaded downdrafts (ie localized straight line wind damage risk).
00Z HRRR shows convection developing early Wednesday afternoon
and moving from west to east across the area through around 8
p.m. This timeframe represents the greatest risk for severe
weather. There will be a frontal boundary near or just south of
the south shores of Lake Ontario, with areas in the northeast
flow on the cool side of the front at a much lower risk for
severe weather. However, non-convective northeast winds will be
quite breezy as the low passes by, with gusts to 35 mph and much
cooler weather. The boundary is likely to be near the I-90
corridor between Buffalo and Rochester but could meander some
during the day.
Wednesday night will remain very unsettled...particularly over
the Eastern Lake Ontario region. The center of the tropical
remnants will drift across the far western counties...while the
axis of deepest tropical moisture and associated will be slowly
exiting via the Thousand Islands and St Lawrence valley. This
could produce an additional inch to an inch and a half rain for
the Eastern Lake Ontario region...bringing 24 hour amounts to
nearly three inches. The highest amounts are expected to be over
Lewis county.
&&
.SHORT TERM /6 PM WEDNESDAY EVENING THROUGH FRIDAY NIGHT/...
By Thursday morning Beryl`s elongated remnant surface low will be
centered across the Lower Great Lakes and Upper Saint Lawrence
Valley...with this continuing to fill as it tracks into Southern
Quebec through the course of the day. While its attendant axis of
deep tropical moisture (and widespread moderate to heavy rains) will
be well to our east by this time...the continued close proximity of
the remnant low will keep clouds and at least some scattered lighter
showers going across the eastern Lake Ontario region through the
day...with upslope flow and wraparound moisture also producing a few
more of these across far western New York. In between...largely dry
weather should prevail across the Finger Lakes. This disparity in
cloud and pcpn coverage will also be reflected in the temperatures
we`ll experience...with highs ranging in the 70s across far western
New York and the North Country...and in the upper 70s to lower 80s
in between. It will also remain on the muggy side...with surface
dewpoints remaining in the mid to upper 60s.
Thursday night surface high pressure and drier air will ridge
northeastward into our region from the Ohio Valley. This will help
to bring an end to any lingering scattered showers...with fair dry
weather otherwise prevailing. Lows will dip into the upper 50s to
mid 60s as surface dewpoints drop back a little more...making for at
least somewhat more comfortable conditions compared to the preceding
few nights.
Friday and Friday night the aforementioned surface ridge will remain
draped across our region...while a weakening mid-level trough passes
by just to our north and west. In the process this latter feature
will brush our region...and this coupled with diurnal heating/
destabilization and developing lake/orographically-forced
circulations could be enough to pop some widely scattered convection
across the Southern Tier and interior Finger Lakes during Friday...
with this activity then weakening with the loss of heating and
sliding eastward Friday night. Have covered this potential with some
slight chance PoPs for now...with dry weather otherwise anticipated.
As for temps...highs on Friday will bounce back to the lower to mid
80s for the most part...with lows in the lower to mid 60s then
following for Friday night. It will also be at least somewhat
humid...as surface dewpoints will generally be in the lower to mid
60s.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
Guidance is starting to trend drier for Saturday as a shortwave
ridge moves into the area. A few showers can`t be ruled out for
eastern areas as a shortwave trough exits to the east.
The next trough tracks into the area on Sunday, bringing the next
potential for showers. Some timing issues still among the guidance
with shower onset time from early Sunday morning through Sunday
night. Thunderstorms will also be possible as instability increases
through the second half of the weekend.
Shower potential will continue into the new work week as a few
shortwave troughs track across the area within a quasi-zonal flow
over the region. Guidance is also slower with a cold front tracking
southeast across the Great Lakes and into the forecast area for the
first half of the work week. Again though, there is plenty of
uncertainty among guidance for timing and shower coverage. Per usual
certainty will start to increase closer to the period and as higher
resolution models start to cover any specific day.
Daytime temperatures will be some 5 to 10 degrees above normal for
the period. Depending on the actual cold frontal passage,
temperatures later in the period, on Monday and/or Tuesday may end
up being cooler.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
VFR flight conditions are in place late this evening, and will
last through around 09Z.
Later tonight and Wednesday the remnants of Beryl will approach
from the southwest. This will bring continued thickening and
lowering cloud cover...and eventually periods of moderate to
possibly heavy rain late tonight and Wednesday...along with some
scattered thunderstorms. This will result in flight conditions
lowering to MVFR/IFR. Wednesday afternoon and evening...enough
instability could develop to bring a risk of some strong to
severe thunderstorms...with this risk greatest south of a rough
KBUF-KROC-KFZY axis. The main threat with any such storms would
be strong wind gusts.
Outlook...
Wednesday night...MVFR/IFR with widespread rain diminishing.
Thursday...Improvement to MVFR/VFR with leftover scattered
showers.
Friday...Mainly VFR with a low chance of showers and thunderstorms
across the Southern Tier/Finger Lakes.
Saturday...Mainly VFR with a low chance of showers and
thunderstorms well inland from the lakes.
Sunday...Mainly VFR with a chance of showers and thunderstorms.
&&
.MARINE...
Low pressure associated with the tropical remnants of Beryl will
push into Ohio, and this combined with high pressure to the
north will result in a tightening pressure gradient.
Northeasterly winds will increase, especially on Lake Ontario
during Wednesday. Based on this, have issued small craft
headlines for the western two-thirds of the Lake Ontario waters,
and the Lower Niagara River.
There also will be several rounds of rain with embedded
thunderstorms moving through. Some storms may produce gusty
winds. The surface low will weaken and move across the eastern
Great Lakes with winds diminishing Wednesday night.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory from 11 AM to 11 PM EDT Wednesday for
LOZ030.
Small Craft Advisory from 8 AM Wednesday to 2 AM EDT
Thursday for LOZ042-043.
&&
$$
SYNOPSIS...RSH
NEAR TERM...Apffel/RSH
SHORT TERM...JJR
LONG TERM...JM/SW
AVIATION...Apffel/JJR
MARINE...Apffel/RSH/TMA
Area Forecast Discussion
National Weather Service Billings MT
104 PM MDT Tue Jul 9 2024
.DISCUSSION...
This afternoon through Wednesday night...
Upper air ridge will slowly move eastward over the western US
into Wednesday night. This pattern evolution will facilitate a
gradual warming trend as low-level winds turn from north or
northeasterly to south/southeasterly due to surface high pressure
over the northern Plains and surface low pressure over Alberta.
Low temperatures will generally be in the 50s and 60s tonight and
Wednesday night, though Wednesday night will be warmer by a few
degrees. High temperatures Wednesday will mainly be in the 90s,
with many places in the upper 90s. Please take precautions if you
are sensitive to the heat.
Much of the area will be dry, though isolated showers and
thunderstorms (20% chance) will occur in the Beartooth/Absaroka
and Bighorn Mountains this afternoon and again Wednesday
afternoon.
In addition, smoke from wildfires burning west of Montana will
begin to move into our area on Wednesday as mid-level flow turns
westerly over the Northern Rockies. At this time the HRRR model
shows smoke staying aloft over our area. RMS
Thursday through Tuesday...
A strong upper ridge will persist through the extended forecast
period, keeping high temperatures in the 90s to low 100sF. Along
with these hot temperatures, little to no precipitation is
anticipated. The chance for elevated showers and thunderstorms
does increase, beginning Thursday and through the weekend.
Generally, the chance for precipitation will be <25%, with the
southern mountains having the best chance. This increased chance
will arrive with some weak energy disturbances moving across the
ridging. The main concerns with any kind of showers/tstorms will
be gusty winds and lightning. As a result of minimal precip
associated with storms, there is increased concern for wildfires,
especially with any lightning activity.
The warmest temperatures of the work week will be felt on
Thursday, with temperatures in the mid-upper 90s and low 100s. The
warmest locations will be in and along the Yellowstone River
Valley. Temperatures backoff slightly on Friday with highs in the
90s to near 100F, before climbing once again over the weekend.
Saturday will be the warmest day in the extended forecast, with
highs in the upper 90s to low-mid 100sF. The warmest locations
will again be in the YRV. Highs will decrease slightly, Sunday
through Tuesday, with 90s to 100F forecasted.
Temperatures on Thursday and Saturday could tie or exceed records
for numerous locations including Billings, Livingston, Miles City,
Baker, and Sheridan, WY. The records for these locations on
Thursday/Saturday are 102F|106F (BIL), 98F|103F (LVM), 103F|106F
(MLS), 99F|104F (BHK), and 101F|107F (SHR).
Relevant probabilities for temperatures to match/exceed values can
be found at weather.gov/byz
Matos
&&
.AVIATION...
Expect widespread VFR over the next 24 hours under strong high
pressure aloft. Matos
&&
.PRELIMINARY POINT TEMP/POPS...
Wed Thu Fri Sat Sun Mon Tue
-----------------------------------------------------------
BIL 063/098 064/101 065/098 065/103 067/100 067/095 065/094
00/U 00/G 10/U 00/G 11/B 11/B 12/T
LVM 058/095 059/097 059/096 059/099 061/096 061/092 058/092
00/U 01/U 10/U 01/B 12/T 22/T 12/T
HDN 059/098 060/102 061/099 061/103 063/101 064/096 062/095
00/U 00/G 10/U 00/G 10/G 11/B 11/U
MLS 063/095 066/100 067/099 066/102 068/100 068/095 066/092
00/U 00/U 10/U 10/G 10/B 11/B 11/U
4BQ 062/095 064/100 067/099 065/103 069/101 069/096 066/094
00/U 00/U 10/U 10/G 10/G 11/B 21/U
BHK 059/093 061/099 063/098 062/099 065/099 065/093 062/089
00/U 00/U 10/U 10/U 10/B 11/B 11/U
SHR 057/095 059/099 061/097 060/101 063/099 063/094 060/093
00/U 00/U 10/U 00/G 10/B 12/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Dodge City KS
616 PM CDT Tue Jul 9 2024
.KEY MESSAGES...
- Isolated showers/storms possible tonight west of Highway 83
- Isolated showers/storms possible for SE counties tomorrow
- Heating up through the rest of the period
&&
.DISCUSSION...
Issued at 200 PM CDT Tue Jul 9 2024
Tonight should be fairly quiet. There is a slight chance (15% pops)
of storms west of Highway 83 tonight. The 3 km NAM and the HRRR indicate
this possibility. The grand ensemble does only show 20% to 30% chance
of >0.01" in this area. As stated, much of the FA should remain dry
with exception to this isolated activity, if it does form in the
first place. Confidence is fairly low. Impacts should be low as well
with perhaps lightning as the main concern if the storms become electrified.
WAA showers might be possible across the SE counties in the morning.
Otherwise, will keep 15% pops for the SE for showers and storms Wednesday
night. Confidence though on this remains low and the grand ensemble
only has a smattering of 20 to 30% chances of >0.01" in this area.
Again, any impacts should be low other than perhaps lightning. Otherwise,
highs Wednesday should be warmer. This agrees with the grand ensemble,
which has 90 to 100% of >90F for the entire FA tomorrow.
The same story of heat will follow for the rest of the period. The
long and short of it is that a 500 hPa anticyclone will move east
from the Desert Southwest and should be over the spine of the Rockies
by Saturday. This is a strong high pressure center around 598 or
599 dm. This supports highs well into the 90s with low 100s possible.
This is particularly true over the weekend. Lows will also trend
warmer during this period starting in the 50s and 60s and warming
into the 70s as the heat continues on. Unfortunately, storm chances
look doubtful overall as the high prevails across the greater region.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 612 PM CDT Tue Jul 9 2024
A weak upper level disturbance embedded in northwesterly flow
will cross the Central Plains early Wednesday morning. As this
upper wave passes, a brief increase in moisture/clouds can be
expected between 9000 and 12000 ft AGL will be possible between
09z and 18z Wednesday. The latest CAMs suggest the development
of some mid level, very light showers/sprinkles during this
time frame also in the Hays area and locations east of Highway
283. However, chances are very low (<15%) and primarily east of
any TAF site, so this was not mentioned in the 00z TAFs. Light
winds will become southerly at less than 10 knots between 03z
and 09z Wednesday.
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Sugden
AVIATION...Burgert
Area Forecast Discussion
National Weather Service Goodland KS
943 PM MDT Tue Jul 9 2024
.KEY MESSAGES...
- Dry conditions likely the next 7 days.
- The heat gradually increases, peaking Friday through Tuesday
with high temperatures generally in the upper 90s to 105.
- Overnight heat indices near 75 degrees Norton/Graham counties
Sunday night and Monday night.
- Daytime heat indices around 100 Saturday Norton/Graham
counties, east of Highway 25 Sunday and Monday.
&&
.UPDATE...
Issued at 753 PM MDT Tue Jul 9 2024
Amplified ridging across the western CONUS continues. Weak waves
continue to ride down the eastern periphery of the ridge which
has led to the development of hit and miss showers and storms
this afternoon into the evening. RAP does hint at some
redevelopment across the southeastern portion of the CWA
overnight so included silent pops due to concerns of dry air
keeping everything as virga. Additional hit and miss storms are
possible across Graham, Sheridan and Gove counties Wednesday
afternoon as well; have included silent pops for those as well.
Thursday afternoon RAP indicates a little better 700-500 mb
moisture developing along an 850mb FGEN boundary across Cheyenne
(CO) and Greeley county. Latest 00Z HRRR is initiating
convection in the area as well. 21Z RAP soundings show an
environment that may support some low end severe weather with
30-35 knots of wind shear, very steep lapse rates and 700 j/kg
of MUCAPE. Will pass along to the next shift to keep an eye on
this for continuity purposes before adding into the forecast.
&&
.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 140 PM MDT Tue Jul 9 2024
Tonight...a clear to mostly clear sky is expected with low
temperatures in the middle 50s to lower 60s.
Wednesday-Wednesday night...mid level dry air moves into the area
from the north, preventing any shower and thunderstorm activity from
developing. High temperatures are forecast to be in the lower to
middle 90s with low temperatures in the upper 50s to lower 60s.
Thursday-Thursday night...this mornings NAM/GFS/ECMWF models do show
an increase in 700-500mb moisture moving into the western half of
the area during the afternoon, potentially supportive of a few
thunderstorms. Overnight, another batch of moisture in the 700-500mb
layer moves into the northeast and eastern parts of the area after
about midnight, potentially supportive of another slight chance for
thunderstorms. High temperatures rise another 3F to 5F per 850mb
temperatures, supportive of readings in the 95 to 100 degree range.
Low temperatures look to be in the 60s.
Friday-Friday night...the tail end of Thursday nights potential
weather system interacts with daytime heating to support a potential
for showers and thunderstorms in the afternoon. Presently, the
forecast dry. If this trend continues, later shifts may need to
introduce some slight chance pops for thunderstorms. High
temperatures rise another 3F to 5F into the upper 90s to around 104
degrees. Low temperatures are forecast to be in the middle 60s to
lower 70s.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
Issued at 140 PM MDT Tue Jul 9 2024
Saturday...an upper level ridge centered over the Colorado will
preclude any thunderstorm potential, despite a hint of sufficient
moisture in the 700-500mb layer across the southeast 1/2 of the
area. GFS/ECMWF/GEM 850mb temperatures support high temperatures in
the 100 to 105 degree range, within a few degrees of the NBM
forecast. Low temperatures remain mild in the middle 60s to lower
70s.
Sunday...the ridge over Colorado Saturday elongates itself over the
central plains. A significant mid level dry slot covers the area,
preventing any thunderstorm potential. GFS/ECMWF/GEM 850mb
temperatures in the 30C to 36C range are spot on with the NBM
forecast highs in the 100 to 105 degree range. Low temperatures
support high temperatures again in the middle 60s to lower 70s.
Monday...NBM model is inserting 20% chances for thunderstorms during
the evening hours. Looking at GFS/ECMWF/GEM 850-700/700-500mb
relative humidity forecasts, they are rather dry and not supportive
of any showers or thunderstorms. It will remain hot with high
temperatures in the 100 to 105 degree range. Low temperatures range
from the middle 60s to middle 70s.
Tuesday...NBM/GFS models support afternoon and overnight chances for
showers and thunderstorms as an upper level trough moves through.
High temperatures are forecast to be in the middle 90s to around 100
degrees with low temperatures in the lower 60s to lower 70s.
&&
.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 941 PM MDT Tue Jul 9 2024
VFR conditions remain forecasted at each terminal for this TAF
period. Overall weak flow will persist as winds will remain
generally light; did introduce a tempo for some gust potential
up to 20 knots at KGLD due to deep mixing forecasted. Wind
shifts will be the story as SSE winds will be present to start
the period before becoming westerly by mid morning and then
northerly by the afternoon.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...None.
NE...None.
&&
$$
UPDATE...Trigg
SHORT TERM...99
LONG TERM...99
AVIATION...Trigg
Area Forecast Discussion
National Weather Service Gray ME
1103 PM EDT Tue Jul 9 2024
.SYNOPSIS...
High pressure offshore will maintain very warm and humid
conditions for much of the week. A stationary front wavering
over the Northeast will provide a focus for showers and storms
into this evening. A trough will approach from the west
Wednesday transporting remnant moisture from Beryl into the
region Wednesday into early Thursday. Thunderstorms are again
possible Friday as a stalled remains over the region. A few more
scattered showers and storms are expected over the weekend.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
1030 PM Update...Showers and thunderstorms have largely ended
this evening. There will probably be some isolated stragglers
overnight, epecially in the mountains. However, those should not
amount to much. Otherwise, expect a warm and muggy night with
areas of fog possible.
Update...
Have updated the forecast this evening as heavy showers and
thunderstorms continue along and near the coastline as of 2242Z
per latest radar imagery. The latest HRRR continues to push this
precipitation off the coast early this evening.
Have made adjustments to the near term portion of the forecast
for temperatures, dew points and winds. Heat Advisories will end
by 00Z for southern New Hampshire.
Prev Disc...
A short wave rotating through Quebec will continue to spread
modest forcing for ascent atop a buoyant airmass over the
forecast area. This will continue the threat for convection
through sunset. Currently, MU CAPE has built to 2000+ J/kg with
deep layer shear around 40 to 50 kts. This will continue to
support strong to severe storms with mainly multi cell clusters
posing a damaging wind threat while a transient supercell or two
will bring an isolated hail threat. After rounds of broken
cloud cover across southern NH, the latest satellite shows
partly to mostly sunny skies here into SW Maine. While scattered
strong to severe storms will remain possible across much of the
area through sunset... portions of south-central NH into SW
Maine are worth highlighting for severe storms into this evening
as recent CAM runs show MU CAPE building in excess of 3000
J/kg. CAMs and recent runs of the HRRR suggest convection will
be pushing off the coast around 8 PM with little to no shower or
thunderstorm activity anticipated thereafter tonight.
It will remain warm and very humid tonight with temperatures and
dewpoints in the upper 60s to low 70s from north to south. This
humid airmass will also likely lead to patchy fog across much of the
area tonight.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
Weak high pressure will be over New England to start the day
Wednesday while an upper trough and the remnants of Tropical System
Beryl approach from the west. This system will draw an anomalous
plume of deep moisture into the area Wednesday through Wednesday
night. The remnant surface low will lift a warm front into the
region Wednesday morning into the afternoon providing a focus for
showers and thunderstorms. The surface low will then track towards
the St Lawrence Valley through Wednesday night for additional rounds
of showers and thunderstorms. As this system moves through the
Northeast the warm front will bring the potential for severe
thunderstorms late Wednesday morning into the evening across
southern NH and SW Maine and the deep moisture in place will bring
the risk for flooding across much of the interior where a Flood
Watch has been issued. For more details regarding the flood threat
please see the Hydrology Section below.
The 12Z CAM suite is in decent agreement that filtered sunshine
will allow the atmosphere to destabilize across central and
southern NH into SW Maine by late Wednesday morning. All the
while, a warm front lifting through the region will lead to
curved and elongated hodographs. CAMs suggest that storms could
initiate near the warm front by early afternoon with the 12Z
HREF highlighting south central NH into SW Maine where storms
could sustain strong rotating updrafts. SPC has placed much of
this area into a Marginal Risk with a Slight Risk over portions
of SW NH. The concern with these storm will be damaging winds
early Wednesday afternoon into the evening and curved hodographs
will also bring the risk for a tornado.
Cloud cover will help keep air temperatures lower than today
while it will still be very warm with highs in the mid to upper
80s. Dewpoints will remain oppressive in the low 70s bringing
heat indices into the low 90s with the potential for a Heat
Advisory needed near the lower Merrimack Valley. Given the
cloud cover forecast have held off on a Heat Advisory for this
package.
The threat for strong to severe storms will diminish into
Wednesday night while the heavy rain threat will continue across
the northern half of the area into Thursday morning. It will
remain warm and muggy with patchy fog likely.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
The remnants of Beryl exits the region Thursday morning, not before
potentially leaving additional heavy rainfall over northeastern
portions of our forecast area. PWAT values will continue to be
extremely high with deep tropical moisture still in place. Areas
river will still be on the rise during this period.
Surface dew points will be in the 70s across much of the region. It
will be on the very warm to hot side once again as at
least partial sunshine develops during the day.
Thereafter, 12Z operational models and ensemble solutions
suggest persistent warmth and humidity will continue throughout
the long range portion of the forecast. Short waves crossing through
the region will allow for scattered showers and thunderstorms most
days, especially during the afternoon hours and away from the
immediate shoreline. The exception may be on Sunday when some
ridging will occur aloft over the region.
Overnight fog may be problematic, especially over the coastal
waters with such high dew points over the Gulf of Maine. Have
included patchy fog most overnight and early morning periods.
A pattern change may occur next week as a trough enters southeastern
Canada. Cooler and drier air may reach New England during that
period.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
Short Term...VFR likely prevailing for much of the night,
although patchy fog cannot be ruled out. KRKD and KAUG will have
the greatest chance for flight restrictions tonight in fog. VFR
likely prevails for all TAF sites Wednesday morning. Showers
and thunderstorms develop late morning into the afternoon and
will bring the threat of flight restrictions mainly along a line
from KLEB to KCON to KPWM and points northward into Wednesday
night. Patchy fog will bring the threat for flight restrictions
across much of the area.
Long Term...Mainly VFR during the daytime hours through much of
the extended. However, there will be some scattered shower and
thunderstorm activity especially during the afternoon and
evening hours leading to brief periods of IFR conditions. LIFR
and IFR conditions may occur during the nighttime periods.
&&
.MARINE...
Short Term...Steady southerly flow will prevail over the waters
through Wednesday while gusts remain at or below 20 kts. Seas
will also stay below SCA thresholds. Storms forming over the
land will have the potential to track into the waters this
evening before diminishing after sunset. Humid air over the
waters will continue the threat for marine fog tonight through
Wednesday night.
Long Term...A persistent southerly flow will continue over the
coastal waters through the period. However, for the most part
this will be below SCA levels. Patchy fog may be problematic
with the high levels of moisture over the region leading to low
visibilities at times.
&&
.HYDROLOGY...
Tropical-like downpours possible Wed-Wed night, Flood Watch in
effect. WPC has issued a rare Moderate Risk for the White
Mountains region of NH, with a slight risk for the remainder of
the CWA. Have left S ME and NH out of the watch based on dry
antecedent conditions and lesser risk of heavier rains.
The remnants of TD Beryl will interact with an incoming upper level
trough over the Great Lakes tonight. The low will track eastward
into New England, where it will pull tropical-like moisture into the
region on Wednesday. PWATs are likely to reach 2-2.25, which is 2-3
standard deviations above normal, and warm cloud depths 14.5-15k ft.
This will support the warm rain collision-coalescence process and
highly efficient rainfall rates. Discrete cells in the early
afternoon should be progressive enough to limit flooding, but there
is the possibility that training and backbuilding will occur. A
northward progressing warm front will stall/occlude by Wednesday
night, becoming the focus for backbuilding/training and the primary
flood risk area. The CAMs and mesoscale models favor a more
southern track with this boundary than the synoptic scale runs,
with the consensus being around the
Lakes/Mountains/international boundary regions. Current
antecedent conditions do not favor widespread flooding as soils
have the capacity to absorb the initial forecasted rainfall and
streamflows are low which is near normal for this time of year.
That being said, the rainfall rates are expected to be extreme
which will overwhelm ground infiltration initially, so rapid
runoff is a concern for all areas particularly in steep terrain.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Flood Watch from Wednesday afternoon through Thursday morning
for MEZ007>009-012>014-020>022-033.
NH...Flood Watch from Wednesday afternoon through Thursday morning
for NHZ001>009.
MARINE...None.
&&
$$
SYNOPSIS...
NEAR TERM...Cannon
SHORT TERM...Cannon
LONG TERM...Cannon
AVIATION...
MARINE...
HYDROLOGY...
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
934 PM CDT Tue Jul 9 2024
.KEY MESSAGES...
- The greatest impacts from post-tropical Beryl will be focused
on areas near and east of I-55. There will be a sharp dropoff in
rain amounts and wind speeds west of the Illinois River.
- Probabilities of over 2 inches of rain range from around 50%
near the I-55 corridor, to 90% from Taylorville northeast to
Rantoul, with late afternoon and evening the greatest period of
concern. A Flood Watch remains in effect along and east of I-55.
- A period of strong winds is expected in eastern Illinois from
around midnight through mid morning Wednesday, with about a
70-90% chance of gusts exceeding 40 mph before sunrise.
- Longer term, heat and humidity return early next week, with
increasing potential for heat index values over 100 degrees.
&&
.UPDATE...
Issued at 934 PM CDT Tue Jul 9 2024
Tornado watch was cancelled earlier, but have made some
adjustments to pops/wx grids for the rest of the night. The
strongest part of the system where the tornado threat was has
moved east of the CWA and no long posses a threat to southeast IL.
However, rain will continue during the overnight hours...mostly
light rain, but some moderate rain will occur at times as the
backside of the system moves east across the CWA. The higher wind
gusts are still a possibility in the east overnight and did not
make any adjustments to them. An update should be coming shortly.
Auten
&&
.SHORT TERM... (Through Wednesday)
Issued at 313 PM CDT Tue Jul 9 2024
Post-tropical Beryl is centered early this afternoon near the
Missouri Bootheel, with a warm front arcing northeast along the
Ohio River. Rain has struggled to get much further northwest than
Peoria, but has been fairly steady south of there the last several
hours. Heaviest rainfall estimates were earlier today along the
northern edge of the rain shield, but more recently have been
focused between Decatur and Flora. As the low lifts northeast into
western Indiana this evening, the heaviest and steadiest rains are
expected near and east of I-55, with highest probabilities of
over 2 inches focused on a Taylorville-Rantoul corridor. LPMM
(localized probability matched-mean) values from the morning HREF
run suggest potential for 3-5 inches in this corridor, and QPF
amounts in this forecast package have been increased as a result.
By midnight, much of the rain west of I-55 should be quickly
fading, but may stick around until sunrise near Champaign and
Danville.
Second item of concern is with severe potential this evening. While
the bulk of the threat will be closer to the Ohio River, latest
WoFS model ensembles suggest a period focused from 5-8 pm down
toward our far southeast counties (Crawford, Richland, Lawrence).
HRRR forecast soundings near Lawrenceville at 5 pm show around
0-1km SRH of around 200 m2/s2, so some brief spinning storms
can`t be ruled out, and the latest SPC Day1 outlook maintains the
level 2 (slight) risk.
Last concern during this period is with the winds. As the low
passes by, wind gusts significantly increase across eastern
Illinois. Gusts of 25-30 mph should be common by mid evening near
and east of I-55, with chances of >40 mph increasing to around
70-90% near and east of I-57 by around 3 am. HREF probabilities of
over 45 mph are around 40% during this period, so there is enough
uncertainty to hold off on an advisory at this point, but a
Special Weather Statement was issued to address the issue. Winds
are expected to drop off by mid morning Wednesday.
Geelhart
.LONG TERM... (Thursday through Next Tuesday)
Issued at 313 PM CDT Tue Jul 9 2024
Longer range upper pattern has a broad trough over the Great Lakes
late this week, lifting out of the area as a 597 dm high builds
across the Rockies. With time, this high will morph eastward
toward the Plains early next week. Some potential for the
northwest flow over the Great Lakes to edge southward and bring
some showers/storms, but at the moment, the main concern is with
heat and humidity. High temperatures likely to return to the 90s
as early as Sunday, with WPC probabilities of >105 degree heat
index values around 40% on Monday.
Geelhart
&&
.AVIATION... (For the 00z TAFs through 00z Wednesday Evening)
Issued at 637 PM CDT Tue Jul 9 2024
Widespread rain continuing this evening over much of central
Illinois, with heavier bands reducing visibility to 1-3SM.
Ceilings have been bouncing around the last couple hours, but a
more sustained period of ceilings below 1,000 feet are expected
through the evening east of a KPNT-KTAZ line. Some general
improvements are expected in eastern Illinois after 08-09Z as rain
moves out of the area, and VFR conditions will prevail there by
about 12Z. Further west, KPIA will remain on the edge of periodic
MVFR ceilings/visibilities tonight, while KBMI/KSPI will mainly be
MVFR through about 08-09Z.
North/northeast winds will continue to trend more northwest this
evening, as low pressure passes to our east, and gusts in most
areas should increase to around 20-25 knots by mid evening. Still
looks to be a sustained period in eastern Illinois where gusts
35 knots or higher will occur, mainly 08-12Z, with gusts backing
off by mid morning.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Wednesday afternoon for ILZ038-042>046-
051>057-061>063-066>068-071>073.
&&
$$
Area Forecast Discussion
National Weather Service North Platte NE
621 PM CDT Tue Jul 9 2024
.KEY MESSAGES...
- High temperatures will range as much as 10 to 15 degrees above
normal in the 90s to low 100s Friday through Monday, with the
threat for dangerous heat.
- While dry conditions are also expected much of the next 7
days, opportunities for at least isolated storm development is
possible Friday/Friday night with higher chances Monday night
into Tuesday.
- Fire weather concerns will increase into the weekend as well,
with very warm, dry, and potentially breezy conditions,
especially across the western Sandhills into portions of
southwest Nebraska.
&&
.SYNOPSIS...
Issued at 304 PM CDT Tue Jul 9 2024
At 3pm CDT, the remnants of Hurricane Beryl was located over
far southeast Missouri. Cumulus clouds are bringing partly sunny
skies across western Nebraska. Winds were light and variable
with temperatures ranging from 83 to 90 degrees.
&&
.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 304 PM CDT Tue Jul 9 2024
Tonight, an upper disturbance on the western periphery of the main
upper trough over the Great Lakes will drop south over the eastern
Dakotas into northeast Nebraska. This may trigger a a few showers or
thunderstorms in northeast Nebraska just east of the area. Will keep
the forecast dry attm, as most models not initiating any convection.
Lows in the upper 50s to around 60.
On Wednesday, a weak front will drop south, turning wind to light
northerly. A weak disturbance will move through Iowa and eastern
Nebraska, and may trigger isolated showers or thunderstorms in
the afternoon near and east of Highway 281. Highs from 85 to 88
in the east to 88 to 92 across the west.
Wednesday night, weak surface high pressure will reside over the
area beneath a mostly clear sky. Lows in the upper 50s to near 60.
Wildfire smoke from Canadian wildfires is shown by the 12Z HRRR
to move into north central into eastern Nebraska Wednesday into
Thursday. Confidence in any surface impacts remains low for
now, though increasingly hazy skies are expected mainly across
the northeastern half of the forecast area.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 304 PM CDT Tue Jul 9 2024
Thursday into Thursday night, the upper ridge axis will build into
Wyoming and Montana. Hot temperatures will move into the western
Sandhills and southwest with highs reaching the mid to upper 90s.
Slightly cooler air from the upper trough over the Great Lakes will
limit highs to 86 to 89 degrees across the east. By Thursday night,
a weak disturbance in northwest flow will cross the area. Models are
mainly dry, but do generate some weak convection overnight, with
differences in location. Will keep the forecast dry attm, but may
need a mention in upcoming forecasts.
Upper ridging will continue to strengthen across the region
Friday through Sunday. High reach the 90s, with upper 90s to
low 100s across the west and southwest Friday and Saturday.
Sunday remains the hottest day across the area. The ECMWF EFI SOT
tails nearing 0.9 for Max T. Forecast highs in the low 100s near and
west of Highway 83 with upper 90s to the east.
The upper ridge will weaken slightly on Monday as an upper
trough moves across the Northern Plains and Great Lakes. The
cold front will remain well north of the area as highs again
reach the upper mid to upper 90s, with 100 degrees or slightly
hotter continuing across the far west and southwest.
Highs in the 90s should continue on Tuesday as an upper trough begin
to move into the region. There is a larger spread in Max T for
Tuesday, so high temperatures could end up slightly cooler.
A slight chance for storms Friday night, mainly across the north
central, although the location remains uncertain. Better chances
look to arrive Monday night into Tuesday as the upper trough to the
north moves in and begins to push a cold front into the area.
Additionally, will have to monitor the potential for elevated to
near critical fire weather concerns as the heat builds into the
area. This will send humidity values falling to near critical levels
Friday through Monday, across the far western Sandhills and portions
of southwest Nebraska. With recent rainfall and green conditions,
fuels should be very limited. Dry conditions do exist across the
panhandle and portions of the southwest, where fuels may become more
receptive.
Breezy winds may accompany the warm and dry conditions at times.
Will monitor the progression of fuels over the next several days as
the warm and dry pattern sets into the area.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 621 PM CDT Tue Jul 9 2024
VFR conditions are expected to continue through western and north
central Nebraska through the effective TAF period. A few high based
fair weather cumulus clouds are noted on satellite this evening, and
are expected to clear out as the evening continues. Winds are
expected to remain light and variable through most of the TAF
period, picking up early tomorrow afternoon with possible gusts at
KVTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Roberg
SHORT TERM...Roberg
LONG TERM...Roberg
AVIATION...Richie
Area Forecast Discussion
National Weather Service Pocatello ID
120 PM MDT Tue Jul 9 2024
.SHORT TERM...Tonight and Wednesday. Hot and dry. We could end the
discussion here, but we figured we would add a little bit more to
it. Several places will be hitting 100 for the first of a handful
of days in a row. Overnight lows will start a trend of remaining
warmer each night, especially within the inversion layer. The
combination of the warmer temperatures and lack of decent cooling
overnight is leading to the EXCESSIVE HEAT WARNING and HEAT
ADVISORY beginning tomorrow and lasting into the weekend. Higher
resolution models keep wanting to blow up any cumulus clouds we
see in the afternoon and evening hours into thunderstorms. While
it isn`t out of the question, the potential is lower than 5% and
this stretching it. Keyes
.LONG TERM...Thursday through next Monday.
By Thursday, we will be in the thick of this excessive, dangerous
heat across all of Eastern Idaho. Excessive Heat Warnings and Heat
Advisories will remain unchanged today, though we will continue to
evaluate for any needed updates as we get through the heat.
Generally speaking, highs on Thursday, Friday, and Saturday will
push 100 to 105 degrees in the eastern Magic Valley, lower Snake
Plain, and valley locations in the South Hills. Highs in the upper
Snake Plain and valley locations in the Central Mountains and
Eastern Highlands will be in the 95 to 100 degree range. Since most
of our record highs for this time frame range between 95 to 105, it
won`t be surprising if we tie/break any records during this stretch.
Winds will also be breezy on Thursday with gusts across most of the
area between 20 to 30 mph in the afternoon. Gusts will be just a few
mph lighter on Friday through Sunday afternoons, but still elevated
enough that we will continue to see critical to near-critical fire
weather conditions as minimum RHs will barely make it to the mid
teens each afternoon.
By the time we get to Saturday and Sunday, a low sitting off the
coast of California and another low over northern Mexico will work
with the high overhead to help funnel in some moisture to the area
and bring some monsoon conditions back to parts of the Southwest and
into Idaho. At this point, it looks like these will be dry storms
and the activity persists into early next week. On the plus side,
this will help kick out some of the worst heat and drop highs back
down a few degrees into the upper 80s and 90s. It`s not much relief,
but it`s an improvement from the triple digits.
AMM
&&
.AVIATION...VFR conditions continue through the rest of today and Wednesday.
Overall, generally quiet weather is expected as high pressure builds
in over the area with no precipitation expected and minimal
afternoon cumulus clouds around 12000-14000 ft. Some thin smoke from
fires in the West is around, but not expecting at impacts to VIS at
this point. Based on HRRR smoke cross section forecasts for SUN, it
looks to hang out around the 650mb level or ~6000 to 7000 ft today.
Of note, as temperatures continue to increase, be aware of increased
density altitudes each afternoon at all sites, but especially at
BYI, PIH, and IDA.
AMM
&&
.FIRE WEATHER...Hot and dry conditions are here, and will last
until we get to the weekend. Expect very low humidity values in
the afternoon, with many places down to under 10%. Overnight
recovery especially in the mountains where some enhanced drainage
winds can develop, will be very poor. We are forecasting some
places to only see overnight values in the 15-25% range. There is
concern that we could see critical fire weather conditions
Thursday and Friday due to combination of wind and very low
humidity across the central mountains (422/475/476), as well the
Snake Plain/Magic Valley(410/425), and along the Utah border in
the South Hills and surrounding areas (425). We will need to
coordinate on the latest fuels to see if we need any warnings, so
stay tuned there. Even if no headlines are issued, with as dry
and hot as it will be...it may not take much at this point. By the
weekend, monsoon moisture will be increasing for a better chance
of dry thunderstorms. Keyes
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 6 AM Wednesday to midnight MDT Saturday night
for IDZ051>055-061-062-065>068-070-075.
Excessive Heat Warning from 6 AM Wednesday to midnight MDT
Saturday night for IDZ056>059.
&&
$$
Area Forecast Discussion
National Weather Service Reno NV
138 PM PDT Tue Jul 9 2024
.SYNOPSIS...
* Prolonged heatwave continues through Friday.
* Increased breezes starting Thursday and chances for
thunderstorms starting Friday may lead to fire weather concerns
into the upcoming weekend.
* Areas of haze and high altitude smoke are possible this week
due to long range transport from California wildfires.
&&
.DISCUSSION...
* Extending the Heat Warnings & Advisories through Saturday
morning as unusually high temperatures are now projected to
linger through Friday, and then with increased cloud cover
Saturday morning`s lows may be the warmest of this entire
episode. Based on the latest ECMWF EFI Thursday could end up
being the hottest overall day for most locations, so it`s not
over yet...
* While nearby Royal Fire isn`t showing much smoke production
today, longer range transport from fires in N Cal (Shelly) and
SoCal (Lake) are sending high altitude smoke over the region.
HRRR shows this potential continuing into Thursday. Can`t rule
out some areas of haze at the surface with mixing - highest odds
over NE California.
* Ridge breaks down, albeit slowly, so we`ll see an increase in
W/SW breezes Thursday into the weekend. But nothing too major
nor widespread. Areas of critical wind & low humidity are
possible but confidence remains mixed on duration and spatial
extent.
* Of perhaps more impact is an increase in moisture working
north, yielding chances for t-storms. Best odds are this weekend
but can`t rule out isolated storms Friday. NBM t-storm POPS are
getting up into the 20-30% range for the weekend. Character of
the storms is TBD, but impacts ranging from new fire starts to
localized heavy rain are on the table. If confidence grows
further, fire weather watches may be considered down the road.
* Next week GEFS/EPS means show the upper ridge remaining dominant
over much of the west with weak troughing off the coast. As such
temps will likely remain above normal with non- zero chances for
t-storms.
-Chris
&&
.AVIATION...
* Typical westerly afternoon and early evening breezes with gusts
20- 25 kts for sites in the lee of the Sierra (KRNO, KCXP,
KMEV, and KMMH). Lighter winds for Sierra terminals, with peak
gusts near 15 kts. Strongest winds 21z-03z.
* A few cumulus buildups once again this afternoon in the eastern
Sierra toward KHTH. High resolution simulations are showing
lesser chances for showers/thunderstorms today, but given the
heat, would still say there is a 10-15% chance in these areas
for a stray storm.
* Taking a look at fire activity around the west, including
latest webcams and high resolution smoke modeling, the highest
likelihood for smoke and haze will be near the Oregon border,
with lighter haze aloft elsewhere in the region through midweek.
Of course, this is dependent on fire activity. The near surface
smoke is fairly minimal, so would not anticipate conditions
dropping below VFR.
* Record hot temperatures most of this week will yield density
altitude concerns for some aircraft at both mountain and valley
airfields.
-Dawn
&&
.CLIMATE...
Record High and Warm Low Temperatures for July 9th-13th at Reno-
Tahoe International Airport (KRNO)
--------------------------------------------------------------------
Date Forecast(High/Low) Record High(Year) Record Warm Low(Year)
------ ----------------- ---------------- --------------------
July 9 104/68 104F (2021) 69F (2021)
July 10 105/66 108F (2002) 72F (2021)
July 11 106/67 108F (2002) 74F (2014)
July 12 105/70 104F (2005,2021) 74F (2002)
July 13 101/73 103F (2014) 70F (2014,2018)
Current record for consecutive days of 100F or greater at KRNO is 10
days, set in July 2021 and July 2005. With 5 days of 100+ so far in
this streak (today being day 6), there is a good chance of tying
this record, with a 80% chance of 100+ on Saturday which would be the
10th day. To break the record on Sunday, that is more iffy, with only
a 35% chance of 100+. On both Saturday and Sunday, increased clouds and
shower potential could keep highs lower than forecast.
The record for consecutive days of 105 or greater is currently 3
days, beating the old time record of 2 days. Today will be critical as
to whether this streak continues, with our forecast high being 104. If
we hit 105 today then the streak will probably get to 6-7 days. 60-80%
chance of 105+ Wed-Thurs-Fri.
&&
.REV Watches/Warnings/Advisories...
NV... Excessive Heat Warning until 9 AM PDT Saturday NVZ001-003>005.
CA...Heat Advisory until 9 AM PDT Saturday CAZ070-071-073.
&&
$$