Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/06/24
Area Forecast Discussion
National Weather Service Binghamton NY
811 PM EDT Fri Jul 5 2024
.SYNOPSIS...
Warm and muggy weather continues this evening and overnight,
with a few rounds of showers and thunderstorms possible.
Saturday features hot and humid weather with an isolated
thunderstorm or two around. Sunny, hot and slightly less humid
conditions return for Sunday and Monday under an upper level
ridge of high pressure. The high humidity returns by Tuesday as
a weak low moves into the area brining renewed shower and
thunderstorm chances.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
730 PM Update...
Showers have kicked off over the western portion of our region
with radar imagery favoring HRRR resolution. Therefore updated
pops using a blend of HRRR and the official forecast to show
the progression of these showers over the next few hours. Also
made slight changes to update temperatures and dewpoints using
current observations. Remaining forecast is on track at this
time.
330 PM Update...
Partly sunny this evening with some lingering
showers and t`storms slowly moving east across the Catskills and
Poconos over the next few hours. Otherwise, temperatures hold
in the 80s along with very muggy dew points into the 70s. Winds
will be light and variable, so it will certainly feel quite
sticky and even hot out there this evening.
Around or just after sunset, the first surface trough moves
through that helps spark off a round of more widespread showers
and thunderstorms. It is possible for a few of these thunderstorms
to become severe as bulk shear is up over 40 knots in forecast
soundings and lifted indexes getting below -5 along with
elevated CAPE staying between 800 and 1850 J/kg through the
night. Hail and wind would be the primary threats with the
stronger storms. A second round of showers and storms then looks
to move through between 2AM and 8AM early Saturday morning.
Once again, a few of these could be strong to severe with
isolated hail, strong winds and torrential rainfall. PWATS are
over 2" on the latest HRRR and warm cloud layer depths extend
over 12k ft.
There remains some uncertainty on the exact timing of these
waves, and exactly when or how fast the rain will exit Saturday
morning. Much of the CAM guidance agrees that it will exit our
eastern zones between 7-10 AM. After this, it will mainly dry
out and surface dew points even start to mix out/decrease some
by the afternoon hours...still 65-72 degrees though. There will
also still be a few pop up showers and storms in the afternoon.
PWATs fall to around 1.3" or less by late afternoon. However,
there will still be 700-1500 J/kg of MLCAPE, DCAPE over 1000
J/kg and 0-6km deep layer shear up to 50 kts. Therefore, we
cannot completely rule out an isolated strong to severe
thunderstorm Saturday afternoon as well. Otherwise, there will
be morning clouds, giving way to mostly sunny skies by
afternoon. Highs will reach the mid-80s to low 90s and peak heat
indices are forecast to range from 85-95 over the area...with
even some upper 90s possible in the Wyoming Valley region. These
numbers are very close to heat advisory criteria, but confidence
on exceeding criteria for any widespread area for 2+ hours was
not quite there at this time...something to monitor in future
updates.
Any lingering showers and t`storms exit or dissipate by
Saturday evening. There will be mostly clear skies as surface
high pressure builds overhead. Winds will be light and
temperatures cooler. Areas of valley fog are likely to form as
overnight lows dip down into the upper 50s to mid-60s.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
250 PM update...
Main concerns in the short term are focused on the typical
summertime hot and humid conditions Sunday and Monday with a few
weak thunderstorms kicking off Monday afternoon.
Weak/broad upper level ridge with gradual rising heights aloft
will lead to widespread suppression over the region Sunday and
Sun night with quiet weather. Precipitation chances are less
than 5% for the entire forecast area of central NY and northeast
PA. Temperatures on Sunday are expected to remain in the mid to
upper 80s in NY and into the upper 80s and lower 90s in ne PA.
Humidity values should be mostly tolerable with dew points in
the lower to mid 60s.
Another night of mild temperatures Sun night/Mon morning with
lows bottoming out in the 60s.
On Monday, a stronger push of the hot and humid air mass from
the south will occur which will allow high temperatures to rise
into the upper 80s and lower 90s for much of the region. Dew
points in the mid to upper 60s will make it feel just slightly
hotter, but still rather uncomfortable. The increased amount of
moisture and instability advecting into the region should lead
to slightly higher chances (10 to 15%) of thunderstorms by the
afternoon. Coverage of any storm that does form should be
isolated, the duration should be brief and the intensity should
be weak.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
250 PM update...
Low chances (10 to 20%) of showers and storms continue Monday
night as the upper short wave to the west gradually moves
eastward into a moist and unstable air mass. The overall forcing
during the night should be weak enough to keep storm intensity
to a minimum.
As Tuesday wears on the boundary layer will heat up once again
and dew points will climb into the lower 70s, which will make it
feel like the lower 90s. Much of the region will be under the
influence of the approach upper wave to the west, amidst the
deep moisture, which will induce widespread showers and storms
(40-60% chance) later in the day Tuesday into Tue night.
There is still quite a bit of uncertainty with respect to how
far east the trough axis/short wave will move. If the boundary
hangs back to the west, then a greater area of showers and
storms will be possible (30-45% chance) through the day
Wednesday. If the system is more progressive then chances will
be 10-25% lower, especially over the western Finger Lakes.
It appears milder air will move in late Wed into Thu with highs
only into the lower 80s along with lower humidity. However,
cannot rule out a few scattered showers and storms pretty much
any day later next week.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
Showers and thunderstorms will be possible this evening and
again early tomorrow morning. These showers and storms may bring
brief IFR restrictions. Conditions will improve by mid Saturday
morning, however more isolated showers will be possible through
the day with brief IFR restrictions.
Outlook...
Saturday Night...Isolated thunderstorms, then areas of fog
overnight with associated restrictions.
Sunday and Monday...Mainly VFR.
Tuesday and Wednesday...Showers and thunderstorms possible,
with associated restrictions.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...Air Quality Alert until 11 PM EDT this evening for NYZ062.
&&
$$
SYNOPSIS...MJM
NEAR TERM...ES/MJM
SHORT TERM...BJT
LONG TERM...BJT
AVIATION...MPK
Area Forecast Discussion
National Weather Service Fort Worth TX
702 PM CDT Fri Jul 5 2024
...New Aviation, Short Term...
.SHORT TERM... /NEW/
Update:
Sub-severe thunderstorms are ongoing in portions of Central Texas
this evening near and just behind a consolidated southward-moving
front/outflow boundary. This activity has been supported largely
by diurnal instability and will continue to wane with loss of
heating over the next couple of hours. Low chances for showers and
thunderstorms will be maintained in the forecast overnight in
parts of Central and East Texas where warm advection in the
vicinity of the 850-700mb frontal surface will exist. However,
convective coverage should be very low or perhaps even nonexistent
contingent on the degree of lift and available instability. No
noteworthy adjustments were made to Saturday`s forecast from
trends discussed below, and we`ll have to monitor surface boundary
locations which will determine which areas of our CWA may be
subject to redevelopment during the daytime.
-Stalley
Previous Discussion:
/This Afternoon through Saturday Night/
Scattered showers and thunderstorms continue across parts of North
Texas this afternoon as an outflow boundary pushes south of the
I-20 corridor. This activity is expected to increase in coverage
through the afternoon mainly along and just north of this
boundary. Latest RAP objective analysis indicates moderate
instability with MLCAPE >2000 J/kg throughout much of our Central
TX counties which will support locally robust updrafts. While
widespread severe weather is not expected, a few strong storms
could produce some gusty winds. Farther north, widespread rainfall
continues across northwest Texas closer to the actual cold
frontal boundary where weak synoptic ascent is also present thanks
to a subtle mid level shortwave. For the remainder of the
afternoon, scattered thunderstorms will continue with the highest
chances from the Metroplex south and west. PW values near 2 inches
and generally weak wind fields suggest that locally heavy rainfall
will be possible through the afternoon and early evening. Activity
should start to diminish in coverage later this evening with loss
of heating. We`ll maintain some low PoPs through the overnight
hours given the proximity of the surface boundaries and generally
moist airmass in place.
On Saturday, the frontal boundary should sag southward into
Central TX where a re-invigoration of convection should occur
through the early afternoon as we heat up and destabilize. We`ll
show increasing PoPs into the afternoon with coverage 40-50%. High
temperatures should be held in check by continued cloud cover and
rain chances with highs topping out in the lower 90s.
Dunn
&&
.LONG TERM... /Issued 339 PM CDT Fri Jul 5 2024/
/Next Week/
Our cold front will retreat north as a warm front on Sunday as a
shortwave trough approaches from the northwest and a lee surface
trough strengthens, with the boundary eventually stalling across
Oklahoma. This will heat things up temporarily, with afternoon
highs climbing into the mid and upper 90s. Dewpoints in the lower
70s will produce max heat index values in the 100 to 105 degree
range. A few spots may exceed 105, particularly in the southeast
where the influx of tropical moisture associated with Beryl could
make conditions exceptionally humid. At this time, however, it
looks like the localized nature and brief time-frame of these
conditions will likely preclude the need for a Heat Advisory.
For those who missed out on rainfall with the ongoing system,
more opportunities will arrive next week as aforementioned
shortwave emerges in the Plains, the front returns south as a cold
front, and Tropical Cyclone Beryl approaches from the south. Rain
chances associated with the front will be mainly Sunday night
through Monday, while those associated with the tropical system
will be primarily Monday through Tuesday. This scenario is based
on the latest operational model solutions (regarding the movement
of Beryl), which match closely with the official NHC forecast.
The severe weather threat appears low at this time, though there
could be some strong winds late Sunday/early Monday as convection
initiating along the front in Oklahoma approaches, particularly if
upscale growth takes place and a cold pool develops. Heavy rain
will become the main concern as Beryl begins to interact with the
slow moving front in the Monday-Tuesday period. Eastern portions
of Central Texas will be nearest the track of Beryl and will have
the best potential of seeing heavy rain. Another thing to keep in
mind will be the potential brief spin-up tornadoes, which could
occur in rain bands where any surface instability is attained.
Showers and storms will end from west to east late Tuesday-Wednesday
as the remnants of Beryl get picked up by another shortwave
trough and carried northeast into the Mississippi Valley. Weak
troughing will linger overhead in the wake of the tropical system,
bringing near to slightly below normal temperatures and low rain
chances Wednesday through next weekend.
30
&&
.AVIATION... /NEW/
/00z TAFs/
Showers and thunderstorms are exiting the TAF sites to the east,
with only lingering light rain present as of 00z. A couple of in-
cloud lightning flashes can`t be ruled out near the terminals for
another hour or so this evening before all convective activity
comes to an end after sunset. VFR skies and a north/northeast wind
will prevail thereafter with multiple VFR cloud decks present
overnight. Convective redevelopment is possible in parts of
Central and East Texas tomorrow afternoon depending on the
location of any surface boundaries during peak heating, but
chances for convection at any of the TAF sites are too low to
introduce into the forecast at this time. Winds should eventually
return to ESE late tomorrow afternoon or evening.
-Stalley
&&
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 75 93 77 96 75 / 20 20 5 20 30
Waco 74 93 76 95 76 / 40 40 5 10 20
Paris 71 93 71 92 71 / 20 10 5 30 40
Denton 71 94 74 96 72 / 20 20 5 20 30
McKinney 72 93 74 95 72 / 20 20 5 20 30
Dallas 75 94 76 96 75 / 30 20 5 20 30
Terrell 73 93 74 94 73 / 40 20 5 20 20
Corsicana 75 93 76 95 76 / 50 40 5 20 20
Temple 74 93 74 96 76 / 20 40 10 10 10
Mineral Wells 70 93 72 96 72 / 20 20 5 10 30
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Green Bay WI
1038 PM CDT Fri Jul 5 2024
Updated aviation portion for 06Z TAF issuance
.KEY MESSAGES...
- Flooding will continue along the Little Wolf River downstream of
the Manawa dam. Do not drive across flooded roadways if
traveling through this area.
- Patchy dense fog is possible over north-central Wisconsin
after midnight.
- On and off chances for showers and thunderstorms will continue
from Sunday through Wednesday. Although the severe weather
threat is low, locally heavy rainfall will be possible.
&&
.DISCUSSION...
Issued at 227 PM CDT Fri Jul 5 2024
Short Term...Tonight and Saturday
The latest RAP analysis and satellite/radar imagery show surface
low pressure moving east between Sheboygan and Milwaukee early
this afternoon. Clusters of showers and thunderstorms have
developed north of this low track in the 925-850mb moisture
convergence zone ahead of the 850mb low and base of the shortwave
trough. These clusters of showers/storms have been augmented by up
to 800 j/kg of mixed layer cape and precipitable water values
(pwats) of 1.30 inches, which is about the 75th percentile. As a
result, and in combination with relatively slow storm motion
(around 12 kts), storms have been prolific rain producers of 1-3
inches per hour and have been locally much higher (Waupaca was
estimated over 5" per hour). The heaviest precipitation will
likely exit east-central Wisconsin by around 4 pm. A Flash Flood
Watch is in effect until 7 pm this evening.
Tonight...Low pressure will continue to track east over the Lower
Peninsula of Michigan and Lake Huron. Cyclonic flow around the low
will continue this evening with low levels remaining moist beneath
the upper trough. A few showers will therefore remain possible
into the evening, but heavy rainfall will not be a threat. Then at
least partial clearing is expected late in the evening and
overnight from northwest to southeast. The clearing skies and
light winds will promote ground fog formation over north-central
and central Wisconsin as forecast temps fall below the cross-over
temps by early overnight. Lows will fall into the 50s except near
the Lake Michigan shoreline.
Saturday...Flattened troughing aloft will remain over the area.
Should see strong solar insolation during the morning, which will
lead to convective cloud development by late morning. Convective
temps are quite low, and only in the middle 70s. With highs in the
upper 70s to near 80 degrees, upwards of 1000-2000 j/kg of
surface based cape is expected which should result in
shower/thunderstorm develop by early to mid afternoon. CAMS
indicate areas along the lake breeze and bay breeze convergence
stand the highest chance showers/storms, but cannot rule out
spotty showers elsewhere either.
Long Term...Saturday Night Through Friday
Focus in this part of the forecast centers around severe and heavy
rainfall potential during the Sunday through Tuesday time frame.
Sunday through Tuesday...Upper troughing will remain in place from
the northern Plains to the western Great Lakes. Impulses moving
through the trough will provide periods of showers and storms. The
first of these troughs is located north of Montana and poised to
reach central Minnesota by 7 am Sunday. This trough with help from
daytime instability of 1000-2000 j/kg will help trigger showers and
storms. An isolated severe thunderstorm threat may develop in the
afternoon given the deep layer shear around 30 kts. The heavy
rainfall risk looks low given the forward storm motion around 20 kts
and pwats just slightly over the mean for the date.
Secondary shortwave impulses are forecast to cross the area on
Monday and Tuesday. Slightly less favorable convective parameters
for severe weather will be in place on Monday due to less shear
aloft. But low convective temps will likely spell an uptick in
coverage and intensity of showers and storms with daytime heating.
More diurnally enhanced showers and storms will also be possible on
Tuesday. Deep layer shear is even weaker by this point, so the risk
of organized severe weather is low.
Rest of the forecast...Relatively quiet mid-Summer weather is
expected for the rest of the week as the upper flow flattens.
Temperatures should trend slightly above normal by the middle of
next week.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1037 PM CDT Fri Jul 5 2024
Clearing skies and wet ground could result in areas of dense
ground fog or low clouds late tonight. The areas most likely to
have dense fog or low clouds late tonight should be north of a
Merrill to Iron Mountain line, and possibly the area west of a
Green Bay to Oshkosh line and east of a Clintonville to Waupaca
line. If low clouds or fog materialize, it should dissipate by
13z.
A few hours of MVFR ceilings are possible between 13z and 16z
Saturday, otherwise VFR conditions and light surface winds are
expected. There could be a stray shower or thunderstorm in the
afternoon or early evening west of a Iron Mountain to Oshkosh
line.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....MPC/MPC
AVIATION.......RDM
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1014 PM CDT Fri Jul 5 2024
...New MESOSCALE UPDATE...
.MESOSCALE UPDATE...
Issued at 956 PM CDT Fri Jul 5 2024
At mid evening local radars showed scattered thunderstorms
gradually weakening over the southwest portions of our CWA. With
the loss of daytime heating much of the convective potential will
end but with the weak frontal boundary dropping through the CWA,
there will be a low chance of redevelopment through the remainder
of the night generally south of Highway 82. Patchy early morning
fog will be possible in the areas that received significant
rainfall but dense fog is not anticipated. /22/
&&
.DISCUSSION...
Issued at 259 PM CDT Fri Jul 5 2024
Rest of this evening through Saturday...
Afternoon analysis indicates frontal zone sinking southward across
the region, leading to widespread showers & storm development across
the Natchez Trace corridor & southward. This is in response to a
highly destabilized & moist tropical environment, favoring tropical-
like downpours & QPF maxima of >3-4" common, with locally higher
amounts possible. The ongoing "Limited" for flash flooding remains
valid into this evening around 10PM or so. There have been a few
cores that have sparked up there or oriented orthogonal to light
west-northwest low-level shear, so some strong-isolated severe
storms remain possible through the evening. Expect convection to
wind down slowly overnight, with a majority of thunder potential
gone around 9-10PM & some showers persisting through around midnight.
HRRR indicates some redevelopment in the wake of this ongoing line,
but current radar trends seem to be focused further northwest. There
could still be some isolated potential in the wake, but likely not
as vigorous, unless moving through untapped thermodynamic profiles.
With clouds & deep moisture, near to seasonably warm lows in the
low-mid 70s are expected.
As the shortwave trough swings across the northeast & another into
the northern Plains, the mid-level ridge will flatten & build more
into the northeast Gulf. This will also be moderated by Tropical
Storm Beryl, which should gradually become more organized into the
weekend across the Bay of Campeche into the southwestern Gulf of
Mexico on the trek near International Border & south Texas coast.
This should keep a deep, anomalous & near climatological maximum
moisture profiles of PWs of 2.25-2.5 inches. Expect rain chances to
slowly begin to creep up before midday, becoming more scattered near
midday & widespread south of I-20 into Saturday aftn. Can`t rule out
some stronger storms again into the aftn-evening hours. HREF prob
match mean of >3" are lower than today but remain possible in the
Hwy 84 to I-59 corridors. Holding off any introduction for flash
flooding in the HWO graphics at this point. Even with more
seasonable highs in the upper 80s to low 90s, sfc dewpoints pooling
in the 77-80 degree range will again favor some potential increased
heat stress for areas along & south of I-20 & east of the MS River.
Added a "Limited" heat in the HWO graphics, with heat indices
peaking near or in excess of 105F briefly. Held off on a heat
advisory for now as convection will modulate the potential, but will
need to be reevaluated. /DC/
Saturday night and Sunday: Though a surface front will sag briefly
into the northern portion of the area this weekend, it appears any
relief in the form of lower dewpoints will mainly be confined to the
Hwy 82 corridor and northward. A moist airmass with dewpoints in the
mid to upper 70s and PW of 2-2.5 inches will remain entrenched
across the remainder of the area. Showers and thunderstorms ongoing
from the daytime Saturday will linger into the early evening across
mainly south MS and central LA before diminishing overnight. Then
another round of showers and storms is likely with daytime heating
on Sunday. Ultimately, the front will begin to retreat northward by
the daytime Sunday. Though daytime temps Sunday may be limited by
increasing coverage of clouds and convection, there may still be
enough opportunity across southern portions of the area for early
heating to result in heat indices rising to near critical
thresholds. For this reason, we will maintain the limited heat
stress hazard graphic into Sunday.
Monday through next Friday: As an upper level trough persists over
the central part of the country and a more subtle ridge axis extends
from the northern Gulf to along the East Coast, southwesterly to
westerly upper flow will continue over our area for much of next
week. This pattern will help to maintain a steady feed of deep layer
moisture across our area, which will keep at least scattered diurnal
convection around each day. We continue to monitor what will happen
with the remnants of Beryl, as this may help to enhance rain chances
particularly Tuesday and Wednesday. Toward the end of the week, the
eastern ridge may begin to wield greater influence, which could
bring warmer and drier conditions.
Of course, we must talk about those pesky heat indices. With higher
rain chances especially earlier in the week, uncertainty is high
with respect to peak temps and heat indices each day. However, at
least limited heat stress issues may persist especially over the
southern half of the area next week. /DL/
&&
.AVIATION...
(00Z TAFS)
Issued at 711 PM CDT Fri Jul 5 2024
The TSRA activity was dissipating and wl not affect TAF sites past
01Z. VFR conditions wl prevail until after 07Z. After 07Z MVFR
conditions wl develop in the se and then over the cntrl and east
MS TAF sites by 10Z. Conditions wl improve by 15Z. Isold to
scattered TSRA will start out in the south and expand into the
cntrl portions of the area during the afternoon. /22/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 74 90 74 90 / 30 50 10 50
Meridian 73 93 73 92 / 30 60 20 60
Vicksburg 73 90 74 89 / 50 50 10 40
Hattiesburg 76 93 76 94 / 30 80 30 70
Natchez 73 88 74 90 / 60 70 20 50
Greenville 73 92 73 90 / 20 10 0 30
Greenwood 73 93 74 91 / 20 20 0 30
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
DC/DL/22
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
834 PM CDT Fri Jul 5 2024
.KEY MESSAGES...
- Showers and isolated storms this afternoon, mainly north of
I-80. Chance of sprinkles/showers Saturday.
- Isolated to widely scattered showers and thunderstorms
possible on Sunday, highest chance (~30-40%) near and
northwest of a Sublette to Antioch line
- Unsettled Sunday night-Tuesday afternoon with periodic showers
and thunderstorms, highest chance/coverage on Monday.
- Seasonable temperatures will continue through next week.
&&
.UPDATE...
Issued at 834 PM CDT Fri Jul 5 2024
No significant changes to the going forecast this evening.
A seasonably-deep upper trough was over the western Great Lakes
region this evening, with a few smaller-scale mid-level
vorticity maxima rotating through the flow. Most notable of
these was exiting southeast WI over Lake Michigan with a
corresponding weak surface low pressure reflection. West-
northwest flow around the south and southwest periphery of the
trough/surface low was producing cool advection into the area,
with mid-level cooling noted in comparing ILX/DVN 00Z RAOBs, as
well as deepening weak instability depicted in RAP forecast
soundings. This has led to an increase in isolated showers from
northeast IA/southern WI int far north/northwest IL over the
last couple of hours, though sunset and the loss of diurnal
warmth in the low levels should allow these to fade in the next
1-2 hours. Until then, a few isolated showers look to be most
likely across our western counties, along/west of the I-39
corridor. Most areas however, will remain dry. Breezy west winds
still sporadically gusting 20-25 mph in some spots will also
diminish with the loss of boundary layer mixing with sunset,
allowing temps to settle into the lower 60s in most areas
overnight (mid-60s in the core of the Chicago area).
Going forecast has all of the above handled nicely, and other
than a few obs-based tweaks (most notably to decrease cloud
cover a bit this evening), no changes are needed.
Ratzer
&&
.DISCUSSION...
Issued at 238 PM CDT Fri Jul 5 2024
Through Saturday night:
Isolated to widely scattered showers will continue this
afternoon--primarily north of I-80--as a robust vort max
pinwheels across southern Wisconsin. Have pared back lightning
chances to the immediate stateline locales where 600-500 mb
temperatures are a bit colder. Farther south, these temperatures
just look too warm to allow parcels to cool much below -10C.
There may be a brief window early this evening about 7-9 pm
prior to the diurnal loss of surface-based instability where
mid-level temperatures cool sufficiently to allow a slightly
better electrification potential. By this point, however,
suspect most activity will be on a downward trend with the loss
of heating.
Otherwise, we increased forecast cloud cover into Saturday
morning and afternoon as guidance is mixing into a lingering
moist layer above 900 mb. Additionally, a check of forecast
soundings shows that, while surface dewpoints may mix out during
the day, sufficient CAPE under the lingering 600 mb temperature
inversion exists to support the development of late-morning and
afternoon sprinkles/showers out of sufficiently deep Cu. Think
the lightning threat will remain quite low once again given the
warmer temperatures aloft, however. Any lingering activity
should diminish through the evening hours.
Carlaw
Sunday through Friday:
On Sunday morning, the remnants of a semi-organized cluster of
overnight showers and thunderstorms to the west of the MS River
may push into parts of northwest Illinois and Wisconsin. Some
potential exists for renewed widely scattered afternoon shower
and thunderstorm development as a weakly capped airmass
destabilizes. However, this would be most favored to occur well
to the northwest of I-55 in the vicinity of any remnant outflow
boundaries. As noted in the key messages, the highest
chances/potential convective coverage are forecast near and
northwest of a Sublette to Antioch line through mid afternoon.
Rising heights and an overall less favorable thermodynamic
environment farther to the southeast should largely curtail the
threat of storms for the southeast half to 2/3 of the CWA. In
addition, increasing subsidence should result in a lull in
convection overall from the late afternoon through the early to
mid evening hours. Highs on Sunday will be well into the 80s for
most (locally upper 80s), except perhaps far NW Illinois and
also along the Illinois shore due to a shore-hugging lake breeze
keeping highs near 80F.
The threat and coverage of showers and thunderstorms should
increase from northwest to southeast across the area Sunday night
through Monday night. This will occur as a slow eastward moving
cold front shifts into the area beneath a series of small scale
mid-level perturbations streaming over the area in the
southwest flow aloft. The highest chances for showers and storms
will remain near and northwest of I-55 Sunday night into Monday
morning, before chances ramp up farther east and southeast
Monday PM into Monday night. The main threat we will have to
keep an eye on with these storms is the possibility for some
locally heavy rainfall given the potential for some northeastward
training along the slow moving cold front and PWATs up to 150%
of normal.
Into Tuesday morning, the surface cold front should begin to
shift east of the area as the main mid-level trough axis makes
steady eastward progress into the Western Great Lakes. However,
in spite of the early frontal passage, chances for scattered
showers and storms will continue into Tuesday as relatively cool
mid-level temps under the upper trough shift over a still warm
and fairly humid post frontal airmass. Accordingly, we continue
to carry 30-50% PoPs. The threat of these showers and storms
should come to a quick end later in the afternoon, however, as
the trough exits east.
For the Wednesday-Friday period, the threat of organized
showers and thunderstorms looks to become rather low owing to
prevailing mid-upper level height rises, overall parched air
aloft, and surface high pressure centered over the northern
Great Lakes. We`ll be keeping a close eye on the remnants of
Beryl as it moves inland from the TX Gulf Coast mid next week.
The last few model cycles (operational models and a majority of
ensemble members) have kept the remnants safely south of the
local area, though there`s certainly plenty of time for large
track changes. Otherwise, expect seasonably mild temperatures in
the 80s for much of the upcoming week, with onshore flow
Tuesday PM through Friday keeping highs at locations near Lake
Michigan roughly in the 75-80F range.
KJB/Castro
&&
.AVIATION /00Z TAFS THROUGH 06Z SUNDAY/...
Issued at 639 PM CDT Fri Jul 5 2024
The primary aviation weather concerns for the 00Z TAF period include:
* MVFR cigs expected overnight possibly stretching into Saturday
morning
* At RFD, a potential for MVFR vsbys overnight in addition to the
cigs
Westerly winds will continue to gust to around 20 kt through mid
evening before subsiding to closer to 10 kt for the rest of tonight.
Meanwhile, isolated pockets of non-impactful light rain will
continue floating across northern IL through mid evening. Periods of
MVFR cigs are looking likely overnight and possibly into Saturday
morning. Confidence in MVFR at any given time is currently too shaky
to warrant prevailing any such conditions in the TAF, although the
06-10Z timeframe does appear to be the overall fan favorite among
model guidance at the Chicago sites and a tad later at the suburban
sites. MVFR cigs may very well hang around beyond daybreak, perhaps
intermittently, but best guess at this point is predominantly VFR
through the morning. At RFD, light ground fog may develop overnight
and provide a period of MVFR vsbys in addition to the cig potential.
This fog does not look to last long after dawn.
Expect NW winds under 10 kt through at least the first half of the
day on Saturday. A lake breeze is progged to move onshore during the
day, although a great deal of uncertainty exists regarding timing
and how far the boundary will protrude inland. Best guess at this
point is that the boundary will cross MDW sometime in the mid
afternoon, although models appear to be trending closer to early
afternoon. The lake breeze looks to cross ORD sometime later in the
day, although guidance appears to be trending toward the idea that
the boundary may stay just out of ORD`s reach and winds will remain
NW through the afternoon. Behind the boundary, expect easterly winds
under 10 kt. A synoptic wind shift will eventually turn all sites to
easterly later in the evening.
Doom
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.
&&
$$
Visit us at weather.gov/chicago
Area Forecast Discussion
National Weather Service Reno NV
142 PM PDT Fri Jul 5 2024
.SYNOPSIS...
* Prolonged heat wave bears down on the Sierra and western Nevada
today and continues into next week. Plan on major heat risk
impacts, even in the mountains. Please take this one seriously!
* No major wind signals are in the forecast. Fire concerns remain
with hot temperatures, very dry air and any remaining holiday
weekend activities. Localized haze is also possible from ongoing
California wildfires.
* Isolated afternoon thunderstorm chances may return next week
within the region with the best chances seen on next Friday, but
low confidence continues at this time.
&&
.DISCUSSION...
The latest RAP analysis shows an upper air high off the coast of
northern CA that controls a large ridge over the western CONUS.
Current surface observations and satellite imagery continue to
report light winds and dry conditions underneath sunny skies for the
region this afternoon. Forecast guidance predicts the upper air
ridge residing over the western CONUS going through the weekend
before moving slightly eastward and tilting in a positive
orientation so that the ridge`s axis passes over the CWA on
Tuesday. Models then have the ridge continuing eastward through
the remainder of the work week with an embedded weak upper air
trough passing over the CWA on Thursday and Friday though the latest
runs of the long term models show some uncertainty in the exact
timing. This evolution in the upper air pattern means that the
surface will continue to see well above normal temperatures and
dry conditions through the weekend and into the next week. But by
the tail end of the next work week, the region may see
temperatures starting a slow decreasing trend with precipitation
chances rising slightly (10-15%) south of US-50 on Friday.
While monitoring of the next week`s trend change will continue, the
main story continues to be the near record to record high
temperatures and warmest low temperatures in the forecast (See
Climate Section for some local records) due to the heat expected
this weekend and the beginning of next week. Overall, some areas
within the CWA expect to see triple digit daytime high
temperatures through the weekend and through next week at this
time. As the CWA expects moderate to major HeatRisk in the
region, the Excessive Heat Warning for western NV and the Heat
Advisory for the CA portion of the CWA continues for Saturday
through Wednesday. Please see the Excessive Heat Warning and Heat
Advisory products for more detailed information on these upcoming
heat hazards. It is recommended to take precautions during this
time such as limiting outdoor activity, taking breaks in a cool
area, staying hydrated, and checking in on neighbors and relatives
that may be more susceptible to heat related illness. For more
heat safety tips, please visit weather.gov/safety/heat.
While models show the CWA staying dry through the rest of this week,
they continue to show single probabilities of precipitation
returning next week which are still pretty low. As mentioned earlier
in the discussion, the latter half of next week may see a slight
increase in precipitation chances. Will continue to monitor to see
if better confidence for precipitation seen in future model runs or
if there is a chance for some dry lightning that may cause a fire
weather concern. Hazy conditions are also possible in the CWA as
well with the ongoing CA wildfires, so will be monitoring for
potential smoke in the area though for now there may be some
slightly hazy skies in some locations for a bit. -078
&&
.AVIATION...
VFR conditions continue at all REV TAF sites again today and are
expected going into the weekend. Typical afternoon breezes are also
in the forecast across the region with KMMH again seeing gusts up to
around 20 kts between 23Z-03Z. Well above normal temperatures
through the weekend and into next week still may produce periods of
density altitude concerns across all TAF sites in the Sierra and
western NV. -078
&&
.FIRE WEATHER...
No changes made from the previous fire weather forecast. High
confidence for well above normal temperatures, low daytime relative
humidity values, and dry conditions persisting through next week.
Winds will remain light with only late afternoon breezes up to 20
mph possible.
As for next week, our more typical afternoon/evening breezes may
return with gusts in the 30 mph range as models show the upper air
ridge shifting slightly eastward. Fire concerns will remain with the
hot temperatures and very dry conditions as well as any remaining
holiday weekend activities. There are also some very slight (<5%)
chances for showers and thunderstorms starting on Sunday afternoon
and going into the beginning of next week. -078
&&
.CLIMATE...
Record High and Warm Low Temperatures for July 6th-9th at Reno-Tahoe
International Airport (KRNO)
-------------------------------------------------------
Date Forecast(High/Low) Record High(Year)Record Warm Low(Year)
------ ----------------- ---------------- --------------------
July 6 105/66 101F(2021+)71F (2007)
July 7 106/71 102F(2014)68F (2004++)
July 8 106/70 104F(2017)71F (2014)
July 9 106/69 104F(2021)69F (2021)
+ denotes record also seen in 2014
++ denotes record also seen in 2001
Current record for consecutive days of 100F or greater at KRNO is 10
days, set in July 2021 and July 2005. The record for consecutive
days of 105 or greater is only 2 days, which has occurred 6 times in
climate history, most recently July 2023. Both of these have the
potential to be broken with this heatwave.
&&
.REV Watches/Warnings/Advisories...
NV...Heat Advisory from 10 AM Saturday to 10 AM PDT Wednesday NVZ002.
Excessive Heat Warning from 10 AM Saturday to 10 AM PDT
Wednesday NVZ001-003>005.
CA...Heat Advisory from 10 AM Saturday to 10 AM PDT Wednesday
CAZ070>073.
&&
$$