Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/25/24
Area Forecast Discussion
National Weather Service Bismarck ND
922 PM CDT Wed Jul 24 2024
.KEY MESSAGES...
- Smoky skies will continue through Thursday, with some near-
surface smoke reducing visibility at times.
- Hot and humid conditions are expected through Friday, with
high temperatures as warm as 107 in western North Dakota on
Thursday.
- Critical fire weather conditions are expected in far
southwest North Dakota on Thursday.
- Chances for thunderstorms return through the weekend.
&&
.UPDATE...
Issued at 922 PM CDT Wed Jul 24 2024
Isolated showers mentioned in the previous update have mostly
dissipated. Otherwise, visibility at most locations is eight
miles or greater, which is a slight improvement from the
previous update. RAP and HRRRSmoke models suggest near-surface
smoke concentrations shouldn`t increase much, if at all, tonight
before continuing to decrease Thursday. This essentially means
visibility isn`t expected to get much worse and will possibly
improve a bit more on Thursday.
UPDATE
Issued at 646 PM CDT Wed Jul 24 2024
Isolated showers have developed in the south central, along with
an occasional rumble of thunder. Added PoPs for the next couple
hours to account for these. Otherwise, patchy near-surface smoke
persists with limited visibility reductions as most observations
maintain 7 mile or greater visibility. Further reductions in
visibility are possible tonight.
&&
.DISCUSSION...
Issued at 257 PM CDT Wed Jul 24 2024
An upper level ridge amplified over eastern Montana continues to
bring hot and smokey conditions across the state. A low level
thermal ridge currently resides over eastern Montana into far
northwest North Dakota down to the southwest North Dakota.
Temperatures out west are forecast to reach the triple digits
(around 103) thus resulting in a Heat Advisory across the far
western portion of the state. Smoke will continue to linger
across the region as wildfires from Canada and now wildfires
from Western CONUS loft their smoke into the main flow of the
ridge. Hence why North Dakota remains locked in a smoky pattern
due to wildfires upstream.
An impulse continues to trek across Western Manitoba into North
Dakota bringing in a chance of showers and thunderstorms to the
far northeastern half of the state this afternoon. Storms will
remain fairly tame due to a lack of shear and instability
resulting in non-severe storms.
Thursday is forecast to be the hottest day of the week as the
upper level ridge passes overhead. This will bring the strong
low level thermal ridge across the state resulting in widespread
tripe digit temperatures (up to 107 out west). In addition dew
points in the 60s will make it feel hot and humid. Therefore,
there is a Heat Advisory for much of western and central North
Dakota Thursday excluding the James River Valley at this time.
In addition to hot conditions, there will be breezy southerly
winds across the state as a strong east west pressure gradient
treks through the Northern Plains. Dew points are forecast to
drop down into the 40s across the southwest resulting in Red
Flag conditions, read the fire weather discussion for more
information.
The upper level ridge will move across the Northern Plains into
the Great Lakes Friday this will result in broad troughing
across the Northern Rockies. Temperatures will cool 10 to 15
degrees across the state however temperatures will remain in the
80s northwest to lower 90s southeast as a cold front pushes
through the state. FROPA could result in storm development
across the state into the overnight hours out east. Stronger
storms are possible shear increases out east. CSU machine
learning program is highlighting the eastern half of the state
to have a low probability of severe weather. There is also a
chance near surface smoke may be pushed out temporarily, but
fires out west will continue to loft smoke back into the region.
Precipitation chances will continue through the weekend as
broad troughing persists opening the door for multiple
shortwaves to move across the region. Temperatures will
fluctuate from the 90s to lower 90s across the region through
the weekend. Ridging could return as early as next week
resulting in another warm up across the region.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 646 PM CDT Wed Jul 24 2024
Patchy near-surface smoke persists, although VFR visibility is
present over all of western and central ND, including the James
River Valley. That said, periodic drops to MVFR visibility are
possible through tonight. Confidence on if/when this will
happen at any particular location is low at this time. A few
hours of LLWS is possible in the northwest and north central
late tonight into early Thursday morning. Terminals potentially
impacted include KXWA and KMOT.
&&
.FIRE WEATHER...
Issued at 257 PM CDT Wed Jul 24 2024
Red Flag conditions are expected across the very far
southwestern half of North Dakota Thursday afternoon.
Temperatures could reach 105 resulting in relative humidity as
low 12 percent. In addition, southerly winds around 20-25 mph
with gusts up to 30 mph. One hour fuels are beginning to dry out
across the southwest due to a lack of rainfall allowing fuels
to be primed for Thursday. However overnight recoveries tonight
will be fair resulting in a relative humidity around 50 to 55
percent in the southwest. This could lead to delayed response
for fuels tomorrow morning, but hot temperatures will quickly
dry fuels out by the afternoon hours. Showers and thunderstorm
are possible Friday morning across the southwest as a cold front
progresses through the region. Thunderstorms and shower could
lead to gusty erratic winds and the cold front will lead to a
wind shift out of the northwest Friday.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 9 PM CDT /8 PM MDT/ Thursday for NDZ001-
009-017-018-031>033-040-041-043-044.
Heat Advisory from 2 PM CDT /1 PM MDT/ to 9 PM CDT /8 PM MDT/
Thursday for NDZ002>005-010>013-019>023-034-035-042-045-046.
Red Flag Warning from 10 AM to 9 PM MDT Thursday for NDZ031-
032-040-043.
&&
$$
UPDATE...Telken
DISCUSSION...Johnson
AVIATION...Telken
FIRE WEATHER...Johnson
Area Forecast Discussion
National Weather Service Boise ID
825 PM MDT Wed Jul 24 2024
.DISCUSSION...Scattered strong to severe thunderstorms with
outflow winds up to 60 mph passed through eastern OR 3-5 PM PDT
and western ID 5-7 PM MDT. As of 8 PM MDT weaker storms were
still active in northern Malheur and Harney Counties and in
Baker County/OR. A Flash Flood Warning is in effect for the Cow
Valley burn scar until 1030 PM PDT due to a thunderstorm that
passed right over the burn scar. Showers and storms will
decrease and end overnight in our CWA from west to east behind
this evening`s cold front. Thursday will be cooler and drier,
and Friday cooler still, as an upper trough passes by to our
north. The Excessive Heat Warning and Heat Advisory will expire
in all areas at 9 PM MDT.
Smoke has decreased due to today`s showers but the Durkee,
Falls, and Telephone fires were still producing lots of smoke.
HRRR model keeps northern Malheur and Baker Counties and the
Hells Canyon area and Upper Weiser Valley smoky Thursday, with
relatively better conditions elsewhere, especially southern
Harney and Malheur Counties. But the HRRR bring another surge
of near-surface smoke southward and eastward over nearly all
our CWA Thursday evening.
Current forecast looks good at this time. No updates planned.
&&
.AVIATION...Low VFR and local MVFR visibility from smoke.
Decreasing showers and thunderstorms tonight. Thunderstorm
outflow winds to 40 kt until 25/06Z. Surface winds variable
tonight, becoming west/northwest 5 to 15 kt Thursday. Winds
aloft at 10kft MSL: SW 25-30 kt. High density altitude during
the afternoon hours due to heat.
KBOI...VFR. Scattered showers and thunderstorms with outflow
winds to 35 kt, ending from the west around 25/06Z. Otherwise
variable surface winds 5 to 15 kt, becoming northwest 10-15 kt
after 25/18Z. Low-level smoke increasing from the northwest
after 26/00Z. High density altitude during the afternoon hours
due to heat.
&&
.PREV DISCUSSION...
SHORT TERM...Tonight through Friday night...The upper level
pattern will go through an adjustment through the end of the
week with a trough of low pressure pushing through the northern
Rockies. This trough will suppress the ridge to the south
providing a respite from the excessive heat. Temperatures will
remain near average Thursday/Friday. The trough, and its
associated cold front will combine with mid/upper level moisture
to generate thunderstorms across eastern Oregon and southwest
Idaho this afternoon/evening. The atmospheric profile supports
strong to severe thunderstorms, with gusty winds the main
threat. Strong storms that develop may produce heavy rain, small
hail, and wind gusts of 40-70 mph (10-20% chance of winds over
50 mph). Blowing dust may also be an issue in/around the
storms. Storms will be active through 10pm MDT. A drying trend
is expected the rest of the period, except for additional
thunderstorms for south central Idaho Thursday afternoon.
LONG TERM...Saturday through Wednesday...Weak troughiness is
expected to linger through the weekend, with a reinforcing low
anticipated for Tuesday. The upper level ridge is expected to
rebound northward Wednesday with the potential for excessive
heat.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Red Flag Warning until midnight MDT tonight
IDZ400>403-420-421-423-424-426.
Red Flag Warning from noon Thursday to midnight MDT Thursday
night IDZ423-424-426.
Excessive Heat Warning until 9 PM MDT this evening
IDZ012-014-033.
Heat Advisory until 9 PM MDT this evening IDZ015-016-029-030.
OR...Red Flag Warning until midnight MDT /11 PM PDT/ tonight
ORZ636-637-646.
Excessive Heat Warning until 9 PM MDT /8 PM PDT/ this evening
ORZ063-064.
Heat Advisory until 8 PM PDT this evening ORZ061-062.
Flash Flood Watch until 10 PM MDT /9 PM PDT/ this evening
ORZ061>064.
&&
$$
www.weather.gov/Boise
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DISCUSSION...LC
AVIATION.....LC
SHORT TERM...MC
LONG TERM....MC
Area Forecast Discussion
National Weather Service Burlington VT
1011 PM EDT Wed Jul 24 2024
.SYNOPSIS...
Showers and storms will continue into this evening, before
weakening and moving out of the region overnight. A cold front
moves through with little fanfare tomorrow, at most bringing a
few scattered showers, mainly over northern areas. Behind the
front, it will become noticeably drier and cooler, setting the
stage for a pleasant weekend. Dry weather will continue into
early next week but the heat and humidity will start to build.
&&
.NEAR TERM /THROUGH FRIDAY/...
As of 1006 PM EDT Wednesday...Thunderstorms and rain showers are
ongoing with strongest storms moving into Rutland Country from
northern New York at this time with scattered activity extending
northward through Chittenden County. Rainfall rates have been
heavy with 0.25" falling in 10 minutes in areas of strongest
convection. So far, no reports of flooding have been noted, but
we could see another round of showers overnight if elevated
instability can hold out; a weaker like is approaching west-east
out of Canada, but decreasing low level CAPE may promote weaker
activity into the overnight hours.
Previous Discussion...Some areas of showers and thunderstorms
have developed across northern New York. A few of these will be
strong to severe, capable of producing damaging winds and small
hail. Areas that have seen training storms could see localized
flash flooding. They will attempt to form a broken line as they
move eastward into Vermont. The showers will gradually weaken a
bit as they travel into Vermont as they will be entering a less
favorable environment. While northern New York had been in the
sun all morning and the atmosphere was able to destabilize
significantly, there have been more clouds and a more marine
modified airmass over Vermont, particularly east of the Greens.
While they will likely remain thunderstorms, the severe threat
is lower over Vermont. RAP estimated CAPE is up to around
1000-2000 J/KG over northern New York while it decreases to
around 500 J/KG in the Connecticut River Valley. The storms will
move out to the east this evening. There could be a few
lingering showers overnight but they will likely not contain any
lightning. Strong boundary layer winds should prevent much fog
formation tonight, despite plenty of recent rainfall. The actual
cold front will move through tomorrow with little fanfare. It
could cause a shower or two to develop but they will not be
severe. There will be a few wrap around showers over northern
areas but these should be light and insignificant. Any rain
chances will end overnight. The cold front will usher in
noticeably drier and cooler weather, with dew points falling
into the 50s and temperatures falling into the 50s and low 60s.
&&
.SHORT TERM /FRIDAY NIGHT/...
As of 314 PM EDT Wednesday...Any lingering shower activity should be
out of the area on Friday. Dry, deep layer northwest flow should
yield an excellent start to the weekend. Anticipate seasonable
temperatures rising into the mid 70s to lower 80s Friday afternoon.
It looks like it could be a good radiational cooling night based on
forecast soundings, and nudged temperatures towards NBM 25th
percentiles and some cooler MOS guidance. This placed some spot
upper 40s in the Adirondacks, mainly 50s for Vermont and northern
New York, and some locations still around 60 near Lake Champlain.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 314 PM EDT Wednesday...High pressure will be in control for
several days. Helping large scale subsidence and maintaining dry air
in our region will be an upper low south of the 40 N, 70 W point. So
get ready for a fantastic weekend of pleasant weather. A south wind
will start to pick up late this weekend. Sunday will be notably
warmer, and could approach 90 in the broader valleys, and likely
reach it near Springfield, VT. Then by Monday, 925hPa temperatures
climb up above 23 C, and that should be enough to start reaching up
and over 90 across a larger number of locations. Towards the middle
of next week, the upper low will begin to dissipate and get absorbed
into another trough tracking eastwards. This feature appears to move
quite slowly. At least the increasing cloud cover and falling
heights should knock some of the edge off the heat, but we`re
probably looking at the return for daily scattered showers and
thunderstorms as early as next Tuesday and likely by next Wednesday.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
Through 00z Friday... Scattered showers and a few diminishing
t-storms will move across the CWA through 06z then mainly dry
with some hit/miss light showers aft 18z Thu across northern
areas. VFR-MVFR through 12z with some IFR due to cigs/vsby due
to fog at KSLK/KMPV although confidence is low to moderate...aft
12z VFR as clouds will be decreasing and drier air will be
micxing in. SSE-SSW winds 5-8 kts thru 10z gradually shifting
SW-W_NW aft 10z around 8-10 kts with some gusts possibly to 18
kts.
Outlook...
Thursday Night: VFR. Slight chance SHRA.
Friday: VFR. NO SIG WX.
Friday Night: VFR. NO SIG WX.
Saturday: VFR. NO SIG WX.
Saturday Night: VFR. NO SIG WX.
Sunday: VFR. NO SIG WX.
Sunday Night: VFR. NO SIG WX.
Monday: VFR. NO SIG WX.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
SYNOPSIS...Myskowski
NEAR TERM...Boyd/Myskowski
SHORT TERM...Haynes
LONG TERM...Haynes
AVIATION...Myskowski/SLW
Area Forecast Discussion
National Weather Service Quad Cities IA IL
650 PM CDT Wed Jul 24 2024
...00z Aviation Update...
.KEY MESSAGES...
- Showers and storms, a few strong to severe, remain possible
into the early evening mainly south of Highway 34.
- Dry and very warm conditions are expected the second half of
the week before turning very warm and humid next week along
with active weather.
- Moderate to minor flooding continues on parts of the
Mississippi River with minor flooding on the lower Rock River.
&&
.SHORT TERM /THROUGH THURSDAY/...
Issued at 300 PM CDT Wed Jul 24 2024
Late this afternoon and tonight, scattered showers and storms
are expected across the southern CWA with the higher potential
along and south of Highway 34 from Ottumwa to Galesburg.
Satellite was currently showing a narrow line of enhanced
cumulus along a boundary going across the IA, MO, IL tri-state
area with a few showers on radar trying to get going. The SPC
has shifted the Marginal (level 1 of 5) Risk further to the
south for a wind and hail potential. CAMs have not been showing
much development until after 5 or 6 PM in an isolated nature in
parts of SE IA. There appears to be another boundary sinking
south to the Highway 30 area where the HRRR was previously
showing some development. It has since backed off. Can`t rule
out some convection closer to I-80 but trends have been to push
it further south. The focus will be in our southern two tiers of
counties, along and south of Fairfield, to Burlington, to
Monmouth, IL roughly between 4 PM and 9 PM. Locally brief heavy
rain will be possible with any of the storms, as the 12Z
sounding at DVN showed a PWAT of 1.43 inches. The storms should
be more progressive however, which should limit the flood
concern. With heavy rain rates, some ponding will be possible.
Overnight, the some lingering isolated showers or storms are
possible along the frontal boundary in the SW CWA. As with prior
nights, some patchy fog will be possible with light winds and
the lingering moisture. Lows will be in the upper 50s to low 60s
NE to the mid 60s SW.
Thursday, any lingering showers should quickly end with plenty
of sunshine by afternoon. Highs will be in the 79 to 84 degree
range.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
Issued at 300 PM CDT Wed Jul 24 2024
Thursday night through Saturday, dry conditions will prevail as
high pressure settles into the area. Highs will be in the low
to mid 80s with lows in the mid 50s NE to mid 60s SW. The light
se wind regime will prevail through this period.
Sunday through Tuesday, return flow on the western side of the
departing high and the eventual approach of a cold front in the
upper plains will bring an increase in temperatures, humidity,
wind speeds, and storm chances. The best rain chances will be
Sunday afternoon east and then Monday and especially Monday
night more area wide. Highs will climb into the upper 80s to
low 90s with lows remaining on the muggy side with readings only
in the upper 60s to low 70s.
A considerable change in the weather pattern will occur next week
as the western heat dome pushes east. The net result is that very
warm and humid conditions will overspread the area. Peak afternoon
heat indices of 95 to 100 are very likely. Depending upon cloud
cover and rain, some heat indices could exceed 100 during the
work week. The Climate Prediction Center has a slight to moderate
risk of excessive heat for the area starting at the end of July.
Rain chances will be dependent upon where the ring of fire develops.
The global models continues to be mixed in their respective solutions,
both deterministic and ensembles.
From a conceptual viewpoint, the organized thunderstorm track looks
to be near the area, possibly just north. If that scenario occurs,
then the possibility does exist for rounds of heavy rainfall and
renewed flooding potential.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 645 PM CDT Wed Jul 24 2024
Scattered to isolated thunderstorms will continue to track
southeastward and stay mainly south of the BRL site through mid
evening. Then overnight, there may be more isolated higher based
showers or storms develop acrs portions of central IA and
possibly move eastward toward the local area. Won`t place these
showers in any TAFs just yet however, as coverage will be low.
Maybe just some mid deck/VFR clouds for the local area. Will
then have to watch for MVFR to IFR fog development toward 10z
Thu morning at most of the TAF sites. Light east to northeast
winds overnight continuing into Thursday. After any morning fog
and resultant low CU lift by mid morning, Thursday looks like A
VFR day with easterly sfc winds of 5-10 KTs.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.
&&
$$
SHORT TERM...14
LONG TERM...14
AVIATION...12
Area Forecast Discussion
National Weather Service Green Bay WI
1040 PM CDT Wed Jul 24 2024
Updated aviation portion for 06Z TAF issuance
.KEY MESSAGES...
- Areas of ground fog are possible late tonight into early
Thursday morning, especially in central and north central
Wisconsin. Locally dense fog is possible.
- After a cool night tonight, temperatures and humidity levels
will be on the rise from Friday into early next week.
- The chance of thunderstorms will return from Sunday through
Tuesday. The severe weather potential is low at this time.
&&
.DISCUSSION...
Issued at 220 PM CDT Wed Jul 24 2024
Short Term...Tonight and Thursday
The latest RAP analysis and satellite/radar imagery show upper
troughing centered across the Great Lakes early this afternoon. At
the surface, high pressure is building in from northern Ontario.
Moisture fluxes off Lake Superior and Green Bay thanks to north
flow has contributed to a widespread cu field across northern
Wisconsin. Ceilings have been gradually rising since about mid-
morning but still have a few ceilings below 3000 ft early this
afternoon. No showers have developed thus far thanks to mid-level
capping and think the warm air aloft will keep the cu field in
check and prevent spotty showers from developing. Scattering of
the cu field is expected later this afternoon due to mixing into
dry air aloft. Forecast concerns mainly revolve around cloud
trends and fog potential over the next 24 hours.
Cloud trends and fog potential: High pressure will settle across
the area tonight. With loss of heating, the fair weather clouds
will dissipate this evening, which will set up a good radiational
cooling night. Forecast temps are forecast to fall well below the
cross over temps at most locations with the exception of the Fox
Valley. Expanded the potential for ground fog and will add a
mention of patchy dense fog to the HWO. With a light east
flow, portions of the Fox Valley to the west of Lake Winnebago
will likely see a lower potential for fog.
The boundary layer looks considerably less moist on Thursday so
don`t expect nearly the cumulus field as today. But do expect
scattered coverage based on upstream conditions over Ontario. Therefore
looking a mostly sunny to partly cloudy day at most locations.
Temperatures: Cool temps are forecast tonight in the 40s and 50s.
These temps are about 5 to 10 degrees cooler than normal to the
north and west of the Fox Valley.
Pleasant temps in the mid and upper 70s are forecast on Thursday.
Long Term...Thursday Night Through Wednesday
Focus of this forecast include warming temperatures late this week
into the weekend as sub-tropical ridging pushes into the region from
the west. This will be followed by rain and thunderstorm potential
during the Sunday thru Monday timeframe when several shortwave
impulses impact the region.
Precipitation: While a stable high pressure system will ensure a
dry period across the region through Saturday, potential remains
periods of showers and storms on Sunday through Monday. Medium range
guidance indicates a shortwave will lift into the Great Lakes region
from the southwest on Sunday. With the high pressure departing to
the east, the airmass will be growing more unstable by this time
although it`s nothing impressive (up to about 1000 j/kg). Therefore,
the potential remains for thunderstorms on Sunday. Despite the more
unstable conditions, weak deep layer shear around 15-20 kts
indicates the potential for severe weather is low.
Additional shortwave energy will arrive from the west on Monday. The
airmass will become increasingly unstable (1000-2000 j/kg of cape)
and looks like the period of highest precip chances. Deep layer
shear remains relatively weak (15-25 kts), but precipitable water
values peak around 1.75 inches during this timeframe so the threat
of heavy rainfall will increase. The relatively weak shear should
keep the risk of organized severe weather low.
For both days, confidence in the details like timing and precip
probabilities are relatively low.
Temperatures: Once the high passes to the east, the airmass will
become warmer and more humid. While excessive heat is unlikely,
highs will be warming into the upper 80s to lower 90s from Sunday
through the middle of next week. Combined with dewpoints in the
lower 70s, heat indices in the low to mid 90s will be possible
during the afternoon hours.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1040 PM CDT Wed Jul 24 2024
Mostly clear across the region tonight with a few
scatter areas of clouds across north-central and east-central WI
with a Canadian high pushing south over northern WI. Clear skies,
light winds, and rapidly cooling temperatures overnight will create
favorable conditions for fog formation at all TAF sites with
IFR/LIFR vsbys possible at times, except MTW where on-shore flow
will persist overnight. Fog development looks most likely between 08-
12Z Thursday morning, and should mix out quickly after daybreak.
VFR flying conditions are expected to prevail on Thursday as the
aforementioned high sits over the region. Scattered pockets of fair
weather cumulus clouds may develop around noon Thursday, but cloud
bases should remain above 4kft.
.OSH... Mostly clear skies over OSH tonight. As temperatures
rapidly cool overnight will need to watch for ground fog develop
between about 3 and 7am at OSH. However, with light flow off Lake
Winnebago expected overnight fog development may be shunted just off
to the west of OSH. Should fog develop it will mix out quickly
Thursday morning. VFR conditions are then expected for the remainder
of Thursday with SCT cumulus based around 4-5kft possible during the
afternoon.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....MPC/MPC
AVIATION.......GK
Area Forecast Discussion
National Weather Service Grand Rapids MI
625 PM EDT Wed Jul 24 2024
.KEY MESSAGES...
- Limited Weather Concerns Tonight through Thursday Night
- Warmer and dry Friday through Saturday
- Seasonable Temperatures and Unsettled Weather Sunday and Beyond
&&
.DISCUSSION...
Issued at 335 PM EDT Wed Jul 24 2024
- Limited Weather Concerns Tonight through Thursday Night
Quiet weather is anticipated tonight through Thursday night with
high pressure dominating the area weather. Outside of a stray rain
shower chance this evening (which looks unlikely) no precipitation
is expected through Thursday night. Clouds that are in place
currently driven by daytime heating will dissipate more and more
as we move through the late afternoon and evening hours. We may
see a little bit of stratus form down towards JXN tonight,
otherwise we should be mainly clear. HRRR vertically integrated
smoke which is overhead now dissipates quite a bit tonight as
northerly winds push it south for the time being.
Thursday into Thursday night the surface high is directly overhead
and mostly sunny/clear skies are anticipated. More smoke pushes in
aloft Thursday evening and Thursday night, which will give the
Thursday sunset a hazy look and likely more pronounced red/orange
hue.
- Warmer and dry Friday through Saturday
The upper ridge building in behind the system currently departing
the area will remain in control of the weather through Saturday
night. This will result in dry conditions persisting. Temperatures
will also be on the rebound from the cooler air mass that will be in
place the next couple of days, as heights build and return flow
advects warmer air in.
- Seasonable Temperatures and Unsettled Weather Sunday and Beyond
The upper high will build east of the region by Sunday, allowing the
next system to move in and bring the next chance of rain to the
area. This system will be the upper low that is currently sitting
over Eastern TX and the western Gulf. This low is forecast to slowly
lift to the NE and be drawn over the area by an upper trough
dropping in over the Upper Midwest.
At this time, it does not look like there will be a widespread rain
with this system. Instead, it will be the focus of mainly afternoon
and evening shower and storm development with peak heating/
instability.
This system moving in and the upper trough settling in from the WNW
then looks to set up a somewhat stagnant pattern through the
remainder of the long term. That pattern will be a broad scale
trough over the region with short waves occasionally moving through
and bringing rain chances. The timing of these rain chances are near
impossible to pin down this far out, so we will have small chances
of showers/storms each day. This will be one of the scenarios with
lots of chances of rain, but it will not be raining much of the time.
Temperatures look generally seasonable through this period. The
trough will keep the real heat suppressed to our south for the most
part. We will see highs in the 80s and lows mainly in the 60s.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 625 PM EDT Wed Jul 24 2024
Skies will gradually clear at all the terminals mid to late this
evening. Some patchy fog or low clouds may develop during the
early morning hours Thursday (mainly at KLAN and KJXN). Any patchy
early morning fog or low clouds will dissipate by mid morning
Thursday. VFR conditions are expected Thursday with nothing more
than some sct fair wx cu Thursday afternoon and early evening.
&&
.MARINE...
Issued at 335 PM EDT Wed Jul 24 2024
Waves are currently in the 2 to 3 foot range at all of our nearshore
buoys which is below Small Craft Advisory and Beach Hazard
Statement criteria. We are expecting an uptick in winds and
correspondingly waves this afternoon due to our advancing high
setup. In this mode, winds increase in the mid afternoon and peak
in the early evening up and down the lakeshore. It is best seen in
HRRR wind and wind gust data. Sustained winds will peak around 18
knots with gusts to around 23 knots. The core of this wind will
occur from Whitehall to Holland which is located near the zone of
clearing. The clearing helps boost the wind a bit through lake
breeze circulation patterns. Bottom line we expect a 3 to 5 foot
wave field to develop from Muskegon County southward this
afternoon and evening. North of there up near the points it may be
a bit harder to reach 3 to 5 feet with 2 to 4 more likely. Given
it being close we have decided to let the headline play out.
Beyond the wind/wave event this evening, a very benign pattern
will be in place with light winds and minimal waves. Waves of 2
feet or less are expected from tonight into Saturday. Winds and
waves will be on the increase Sunday into Monday as south flow
increases.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement until 10 PM EDT this evening for MIZ037-
043-050-056-064-071.
MARINE...Small Craft Advisory until 10 PM EDT this evening for LMZ844>849.
&&
$$
DISCUSSION...Duke/NJJ
AVIATION...Laurens
MARINE...Duke
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
951 PM EDT Wed Jul 24 2024
.SYNOPSIS...
A nearly stationary front will meander across our region for the
next few days providing a focus for above-normal chances of mainly
afternoon and evening showers and thunderstorms. Temperatures will
be a little cooler than normal at the end of the week then return to
seasonal normals to start next week.
&&
.NEAR TERM /THROUGH THURSDAY/...
As of 944 PM EDT Wednesday: No major changes tonight. Scattered
showers are in place across the Upstate and NC Foothills, with
some embedded thunder. Rain rates are on the downhill, and HREF
/ HRRR QPF estimates continue to stand below concerning levels.
As expected, increasing moisture from the southwest is driving
a resurgence in activity coming out of central GA and the lower
Savannah River Valley as a weak shortwave now analyzed over AL
starts lifting north.
Expect this activity still to reach the area after midnight.
poPs ramp up to 50-60% across much of the area during this time
frame. Convective character should trend toward showers...although
some of those could be heavy, but isolated to widely scattered
thunderstorms are also expected. Increased coverage of convection
should result in an uptick in the excessive rainfall/flash flood
potential, but the threat continues to appear too localized to
warrant Flood Watch consideration.
For tomorrow, a short wave passing over the northeast quadrant
of the country will push the northern portion of the trough that
has been west of our area for several days to the Mid-Atlantic/
Northeast coast, while the southern part of the trough is forecast
to be left behind...really evolving into more of a weakness in a
strengthening subtropical ridge...over the lower Miss Valley/ Texas.
This will result in continued (albeit weakening) deep/moist SW flow
over our region. The early part of the day should be marked by
weak subsidence/dwindling nocturnal convection. Weakly confluent
low level flow/lingering weak boundary as well as terrain effects
will continue then provide the main foci for diurnal convective
initiation...while overall coverage will again depend upon the
degree of destabilization...which could again be limited by morning
cloud cover. A preponderance of the guidance support 50-70 PoPs
across the area. Temps are expected to be near normal through
the period.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
As of 1230 PM Wed: Expect to be slowly getting away from the rich
PWATS throughout the the period as a continental airmass beings to
impinge upon the region. The greater than 2" PWAT values are
progged to be displaced well offshore and south of the CWFA by 00Z
Sunday, although perhaps just the NC Piedmont realizing the
reduction in diurnal enhanced tstm chances by then. Given the
ongoing favorable pattern, developing eastern CONUS upper troughing
and a lingering llvl baroclinic zone, daily tstm chances will not
stray too far from the ensemble consensus, cvrg still blossoming to
numerous Friday afternoon along with the standard isolated excessive
rainfall possibility. With the upper trough axis progged to
progress to the coast Saturday and the corresponding reduction in
PWAT values, the NC piedmont has a real possibility of remaining
capped that afternoon. Still planning on the string of below normal
max temperatures to continue for Friday with even less warm
conditions on Saturday thanks to the developing llvl NEly flow.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 100 PM Wed: Upper ridge axis builds north atop the region to
start off the period as max temperatures climb back toward climo on
Sunday. It remains probable that lingering low PWAT values will
preclude any tstm development along and east of the I-77 Sunday
afternoon, but energy riding up the back side of the ridge should
aid in storms becoming numerous again in the mountains. During the
first half of next week, the pattern features developing eastern
CONUS troughing which will promote above climo tstms chances each
day through the end of the period along the a return to typical late
July warmth and humidity.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
At KCLT and elsewhere: It`s a pretty gross aviation forecast for
the next 12-18 hours, as increasingly moist air allows another
round of evening convection to develop. Even the rapid-refresh
model guidance has really struggled with the evolution of today`s
weather, and as of around 2330z convection is just firing up across
the NC Foothills while a long-lived band of showers and embedded
thunder are creeping into the SC Upstate from the south. As of
yet, all the TAF sites are VFR with VCSH/VCTS warranted...and
while it`s unclear whether the increasingly stationary cells
over the southern Upstate will make much more progress north,
a TEMPO for SHRA was warranted at KAND. Elsewhere, TEMPOs were
added or PROB30s maintained during the overnight hours...when the
bulk of guidance depicts a lobe of better moisture and colocated
upper-level disturbance pivoting across the western Carolinas.
It`s likely that this would consist of SHRA/+SHRA and embedded
TSRA...in turn lowering visibility and especially ceilings to IFR,
at least. Slow improvement is expect after daybreak, as rain lets
up...but like today, it could be slow to clear up, and if that`s
the case, restrictions may linger well into late morning or even
early afternoon at some terminals. Winds will be light and variable
overnight, generally SW by day, through the period. Another round
of afternoon convection is anticipated on Thursday...but again,
the exact progression of this activity is unclear. In fact, some
of the more convincing models indicate that SHRA may never entirely
end west of I-26, in favor of just a lull by morning followed by
a resurgence of activity in the afternoon as activity pushes east.
Outlook: Expect another round of possible flight restrictions
Thursday night, and then afternoon convection again on Friday.
Morning fog/low stratus will be possible each day through the
first part of the weekend, especially in the mountain valleys and
any locations which received heavy rainfall the previous afternoon.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...DEO
NEAR TERM...JDL/MPR
SHORT TERM...CSH
LONG TERM...CSH
AVIATION...MPR
Area Forecast Discussion
National Weather Service Gray ME
1030 PM EDT Wed Jul 24 2024
.SYNOPSIS...
Low pressure over the Great Lakes region will move north of New
England tonight and through Thursday which will push a cold front
through the region. This will result in a few showers and
thunderstorms tonight and again on Thursday. Areas of fog will
also be possible overnight...especially along the coast. High
pressure will bring drier air along with warm temperatures for
Friday through the coming weekend. Next week...the heat and
humidity will build...though no significant shower or
thunderstorm activity is expected for the first half of next
week.
&&
.NEAR TERM /TONIGHT/...
1030 PM Update...Areas of light rain and drizzle are still
present across the forecast area as locations begin to reach
saturation. The line of convection we have been keeping an eye
on is just pushing into Vermont at this hour and has exhibited
weakening. SPC mesoanalysis shows little to no instability left
over the forecast area so it is expected to lose steam over the
next couple hours, reaching the CT Valley as just showers. Made
minor adjustments to temperatures and dewpoints to align with
observed trends. Otherwise, the forecast remains on track.
635 PM Update...Much quieter tonight as there are only a few
light showers and sprinkles out there at the moment, mainly in
and around the mountains. Will be continuing to monitor the
convection off to our west as 18z CAMs and the last few runs of
the HRRR continue to show a line making a run at us later
tonight. As usual it is running against the clock as what little
instability was able to develop in western New Hampshire will
be beginning to wane here shortly. A strong storm in the CT
Valley isn`t out of the question, but a quickly decaying line
seems like the likely scenario. Made very minor updates to sky,
temperatures, and dewpoints to align with observed trends.
Previous Discussion...
High Impact Weather Potential: Locally dense fog possible...
particularly along the coast.
Pattern: Early afternoon water vapor imagery shows a significant
short wave trough moving through the Great Lakes region with a deep
moisture plume along the east coast. At the surface..much of
New England finds itself between two stationary fronts...one
along the international border and the other just south of New
England. Weak...moist southerly flow over the southern boundary
has led to showers across western Maine today with regional
radar showing additional shower/storm activity across upstate
New York in the broad warm sector ahead of the surface low east
of Georgian bay. The primary forecast focus will be on this
upstream convection as it approaches the area this evening.
Through this evening: Mesoscale guidance shows nearly all of the
meaningful MLCAPE remaining west of the CT Valley as we move into
the evening hours. Can/t rule out a few isolated showers...but
expect the current activity in Maine to wane with no other organized
areas of showers through 8pm. It will remain warm and humid through
8pm with temperatures in the upper 60s to around 70.
Tonight: Upstream convection congeals into a line this evening
across upstate New York...making a run at the CT Valley towards
midnight. Timing and implied decrease in instability favors a
decaying line of showers largely falling apart as it arrives
overnight. Thus...expect mostly a quiet night with some showers
and possibly a rumble of thunder towards the CT Valley. Clouds
and moist airmass will keep temperatures up again...with most
locations remaining in the 60s overnight.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
High Impact Weather Potential: A strong storm or two possible
across western Maine Thursday afternoon.
Pattern: Surface low pressure passes north of New England during the
day Thursday with mid level height falls over the region associated
with shortwave trough axis. Core of the midlevel trough arrives
Thursday night behind the cold front with a slowly drying llevel
airmass. Primary forecast challenge centers on the potential
for shower/thunderstorm development ahead of the surface cold
front.
Thursday: Surface cold front will be over the CT Valley daybreak
Thursday...poised to push east through the day. Given the frontal
timing...convective potential looks to increase as you head
east...which allows for the most destabilization. Thus...by early
afternoon MLCAPE values reach around 1000 J/kg with 30-40kts of mid
level flow. Therefore...there is a window in the 2pm-5pm timeframe
for a few robust thunderstorms from the western Maine mountains east
through the Capitol region. Temperatures will be warmer than the
past few days as morning fog/low clouds gives way to some increasing
sunshine with highs in the mid 70s to lower 80s.
Thursday Night: Additional vort max associated with the trough axis
arrives with mid level height falls continuing. Despite drying
llevel airmass..this forcing should allow some mountain showers to
continue with partial clearing in the west northwest flow to the
south of the mountains. Lows should fall into the mid 50s in the
mountains to around or just above 60 along the coast.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Overview: Overall warming trend with little activity late this
week through the weekend as high pressure passes through the
region. General forecast is a couple days of highs in the upper
80s to around 90 through early next week, but not near the
amount of humidity we saw earlier this month. The next chance
for widespread rainfall in the region comes towards the middle
of next week.
Details: On Friday, will see weakening sfc cold front slide
across the north amid upper trough and prolong some light
showers there, but largely expect a rain free end of week and
weekend. Skies should thin through the morning for a mostly
sunny afternoon. Offshore surface winds should prevent much of a
seabreeze from developing in the afternoon, and will allow the
coast to also warm well into the mid to upper 80s.
Clear skies and lightening winds Friday night should allow the
surface to decouple a bit, with temps falling into the lower 60s
to upper 50s overnight. It may be closer to low 50s across the
north, especially in valleys where winds may slow earlier in the
evening. Kept the mention of fog in the Upper CT Valley late
overnight.
Main weather feature for the weekend and early next week will
be a slow moving surface high pressure. This will cross the
Great Lakes Friday, with the center dropping across the Mid-
Atlantic Saturday. Temps Saturday will be comparable to Friday,
but expect less NW component to surface winds. Will likely see
the potential for afternoon seabreeze Sat and Sun amid this more
favorable wind direction. Otherwise, temps and dew points will
rise into early next week. Dew points will be a bit more
manageable this time around vs. earlier this month, which means
not as severe humidity, lower heat indices, and better relief
during the overnight periods. Currently have heat index values
pushing into the lower to mid 90s, and will continue to
advertise this in the HWO as we get closer.
Ensembles have this high skirting off the East Coast come Monday
evening/Tuesday. On its heels is a sizable plume of moisture
that converges on return flow and low pressure crossing the
upper Great Lakes. This will bring our next chance of rain
across the area. For now, there remain differences in how
consistent this rainfall is, but unsettled conditions appear
likely through mid to late week.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
Short Term...
Summary: Showers...low clouds and fog will dominate conditions
through tonight with improvement Thursday morning before a few
showers and possibly a thunderstorm over western Maine Thursday
afternoon. Clouds and a few showers will continue in the mountains
Thursday night with partial clearing elsewhere.
Restrictions: Largely MVFR attm with conditions expected to
deteriorate around sunset this evening with low clouds and fog
resulting in LIFR/IFR conditions overnight. Improvement to VFR is
expected Thursday morning with isolated restrictions in the
afternoon across western Maine with some showers and
thunderstorms. Some MVFR restrictions will linger at HIE
Thursday night /due to clouds and a few shras/ with fog
possible at LEB...and VFR elsewhere.
Winds: Southeast winds 5-10kts will diminish to 5kts or less
tonight before shifting to the west southwest 10-15kts for the
day on Thursday before shifting northwest 5-10kts Thursday
night.
LLWS: No LLWS is expected through Thursday night.
Lightning: Low potential for a thunderstorm near LEB overnight
/<20% chance/. There is some potential for a thunderstorm at
AUG Thursday afternoon. Otherwise...thunder potential is low.
Long Term...VFR ceilings and vis expected Friday through the
weekend. MVFR should be scattering out Friday morning from the
mountains. There may be overnight valley fog developing near
rural terminals like LEB/HIE through the weekend.
&&
.MARINE...
Short Term...Dense fog is possible over the waters tonight
through Thursday morning. Winds and waves are expected to remain
below SCA levels through the short term forecast period.
Long Term...Below SCA conditions expected. High pressure will
reside just south of the coastal waters over the East Coast
Saturday and Sunday. This moves east into Monday and Tuesday,
with more unsettled conditions possible mid week next week.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.
&&
$$
UPDATES...Baron
NEAR TERM...Arnott/Schroeter
SHORT TERM...Arnott/Schroeter
LONG TERM...Cornwell
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
847 PM CDT Wed Jul 24 2024
.KEY MESSAGES...
- Widely scattered thunderstorms will be possible through
tonight...primarily southwest of the I-74 corridor.
- Cooler/drier weather will prevail Thursday through Saturday.
- Summertime heat will return early next week...as peak afternoon
heat index readings top the 100-degree mark by Monday.
&&
.UPDATE...
Issued at 847 PM CDT Wed Jul 24 2024
01z/8pm surface analysis shows a nearly stationary frontal
boundary extending from Kirksville, Missouri ESE to just south of
Terre Haute, Indiana. While other weaker boundaries/wind shift
lines exist further north into northern Illinois, this will be the
primary forcing mechanism for additional scattered convection
through the night. Latest radar imagery shows a few cells
along/north of the front from Macomb to Decatur. Have updated PoPs
to focus on this corridor through the remainder of the evening and
into the overnight hours. Further north where forcing is weaker,
have maintained slight chance PoPs for a couple more hours, then
went with a dry forecast overnight along/north of the I-74
corridor. Even though the main synoptic boundary has passed all
but the far S/SE KILX CWA, the boundary layer airmass to the north
remains moist as evidenced by surface dewpoints in the middle to
upper 60s as far north as I-80. With light winds and partly cloudy
skies, think patchy fog will develop across the entire area
overnight. Will need to keep an eye on locations near the boundary
where winds will be calm, as the fog could potentially become
dense in a few spots. CAMs do not have a particularly good handle
on the fog: however, the RAP has been hinting at visbys
potentially below 1 mile along a Macomb to Effingham line toward
dawn. Have added patchy fog everywhere after midnight...and will
continue to monitor later runs of the CAMs as well as local
observations in case the fog becomes thicker/more widespread.
Barnes
&&
.DISCUSSION...
Issued at 320 PM CDT Wed Jul 24 2024
A cold front is just south of the I-74 corridor this afternoon, with
scattered thunderstorms in east-central IL along the front,
coincident with an upper level shortwave, while west-central IL has
much weaker and less thunderstorm activity. The shortwave will
propagate east of the area the next few hours, which could lead to a
lull in activity for a couple hours, however clearing skies and
plenty of diurnal heating should be able to keep near 2000 J/kg
MLCAPE in the frontal zone, along with around 30 kt bulk shear.
Storms will likely redevelop in the frontal zone again late this
afternoon and evening as subsidence behind the outgoing shortwave
wanes. SPC continues a Marginal Risk for severe thunderstorms from
around a Canton to Bloomington line southward to a Taylorville to
Charleston line. As the front sags southward overnight, it will move
into a less sheared area, while instability gradually wanes under
1000 J/kg. This should eventually decrease storm intensity by around
10 pm to the point severe storms will no
As the cold front sags south of central IL, high pressure will
set up over the Great Lakes, providing subsidence for mostly clear
skies Thursday and Friday. Flow around the high will also push a
cooler and drier air mass into the area. Lows should be in the mid
60s primarily tonight, but dip into the upper 50s Thursday night,
while highs run a few degrees below normal, with highs low to mid
80s Thursday and Friday.
The high will move off to the east this weekend into next week,
allowing southerly flow to return high moisture levels to the area,
with above average precipitable water forecast again Sunday into
early next week. A weak trough over the central IL should ensure
chances for occasional showers and thunderstorms. Highs look to warm
into the lower 90s by early next week, along with afternoon heat
index approaching 100.
37
&&
.AVIATION... (For the 00z TAFs through 00z Thursday Evening)
Issued at 638 PM CDT Wed Jul 24 2024
Several boundaries are evident across central/northern Illinois
early this evening: however, it appears the primary focus for
scattered convection will remain along/south of a KEOK to KHUF
line. Have therefore removed all mention of thunder at the I-74
terminals through the entire 00z TAF period. Further south, have
included a 2-hour period of VCTS at KSPI as a small cluster of
thunderstorms currently over northern Morgan County slowly pushes
southeastward. Once this storm clears KSPI, have only mentioned
VCSH at KSPI/KDEC for the remainder of the night as the boundary
remains nearly stationary or drops very slowly southward. The
other aviation forecast concern will be potential fog development.
Even though the main frontal zone has dropped into south-central
Illinois, ample boundary layer moisture remains in place northward
to the I-80 corridor. Winds will be NE at less than 10kt, but
will become light/variable near the front. GFSLAMP suggests
widespread patchy fog overnight, while the RAP is beginning to
focus its lowest visibilities in the immediate vicinity of the
boundary. As a result, have lowered visbys to 2 miles in fog at
both KSPI and KDEC between 09z and 13z. Further north, have gone
with 4-5 miles at the other terminals. Once any early morning fog
dissipates, mostly clear skies with NE winds of 8-12 miles will
prevail for the remainder of the day.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Indianapolis IN
937 PM EDT Wed Jul 24 2024
.KEY MESSAGES...
- Isolated thunderstorms overnight.
- Wildfire smoke at times which may reduce visibility and air
quality
- Seasonable temperatures in the 80s through this weekend gradually
warming to near 90 early next week.
- Dry late week weather will be replaced but warmer and unsettled
weather by late weekend.
&&
.FORECAST UPDATE...
Issued at 936 PM EDT Wed Jul 24 2024
- Small overnight thunderstorm chances along and south of I-70
overnight
- Patchy Fog possible
Surface analysis late this evening shows a frontal boundary
stretched across Central Indiana, just south of I-70. The gust front
from earlier convection was south of the IND forecast area. Any of
the remaining shower/storm activity was found along or south of this
boundary. A few lingering showers/storms were found upstream over
Central IL. High pressure was found over WI and MI. This high was
building its influence farther south into Indiana. Dew points across
Central Indiana remained rather humid, in the upper 60s to near 70.
Overnight the strong high pressure system to the north is expected
to continue a slow, southward sag across Indiana. Meanwhile, the
HRRR continues to suggest isolated thunderstorm redevelopment along
the frontal boundary early in the overnight night hours. Coverage
appears quite limited as energy arrives from IL. Thus will include
some small pops along the frontal boundary. Otherwise, dew point
depressions are suggested to fall to less than 2F at many spots.
This may result in some patchy fog. Isolated dense fog cannot be
ruled out. Ongoing lows in the low to middle 60s are on track.
&&
.SHORT TERM (This evening through Thursday)...
Issued at 257 PM EDT Wed Jul 24 2024
Scattered thunderstorms have developed across much of the area as of
2pm. One cluster of storms, which passed through the northern parts
of the CWA, is now exiting eastward into Ohio. A second cluster of
storms, currently just beyond the Illinois state line west of
Lafayette, is moving southeastward. Additionally, isolated to
scattered storms have popped up along the first cluster`s outflow
boundary and in the preceding air mass.
ACARS soundings out of IND show deep but fairly skinny CAPE
profiles. Lapse rates are steep near the surface, but become poor in
the mid to upper levels. Additionally, a lot of dry air is present
above 700mb. Updrafts have been shallower than the CAPE profile
would otherwise suggest. This is likely due to relatively weak
forcing and dry air entrainment. Hodographs are short, with the
fastest flow occurring above the EL and thus not likely to impact
storm organization. As such, storms should behave more or less like
single cells or multicell clusters today. Given the amount of dry
air, sufficient DCAPE (500-1000 J/Kg) exists for cold pool
generation. Any transient cold pools could allow for additional
storm-scale organization into a weak MCS.
As for convective hazards, strong gusty winds are the primary threat
today. As mentioned above, enough DCAPE is present for cold
downdrafts which may allow for brief downburst potential.
Furthermore, if a weak MCS manages to form then some enhancement
from rear inflow jets may allow for bowing segments/strong wind
gusts. Hail is possible, but as of right now updrafts may not become
vigorous or tall enough to support large (over 1 inch) stones.
Tonight, lingering showers and storms may occur as a cold front
slowly sags southward. This front should pass through within the few
hours around midnight. Drier flow from the northeast should take
hold, allowing for a clearing trend as we head into Thursday.
However, before this occurs, there may be enough time for patchy fog
to develop...especially south of the front. The front should help
clear out any lingering wildfire smoke as well. Highs on Thursday
will be cooler, but remain in the upper 70s to lower 80s which is a
touch below normal. An isolated shower across our far southern
counties is possible tomorrow, though this is conditional on how
quickly the front exits the area.
&&
.LONG TERM (Thursday night through Wednesday)...
Issued at 257 PM EDT Wed Jul 24 2024
Thursday night through Saturday morning...
The long term will start off with the cold front well south of the
area as high pressure builds in across the Great Lakes and a ridge
builds over the nation`s mid section. Subsidence associated with the
high along with a dry column per model soundings supports dry
weather through at least midday Saturday. ENE winds around the high
will result in comfortable humidity levels, although little cloud
cover will still allow temperatures to come close to seasonable
afternoon highs in the middle 80s. Meanwhile, dew points mostly in
the upper 50s and lower 60s a good radiational cooling setup will
mean overnight lows will mostly be in the upper 50s to lower 60s.
The surface high will shift to the Appalachians by late Saturday.
This will allow for Gulf moisture to build over the Ohio Valley.
With this in mind and an approaching Plains upper trough, would not
rule out a thunderstorm or two over far southwestern parts of
central Indiana Saturday afternoon and evening. That said,
confidence in convection is low with the trough still a bit to the
southwest of the area.
Saturday night through Wednesday...
Gulf inflow will continue late in the weekend and into next week.
Meanwhile, an upper low pressure system will move from the Plains
into the Great Lakes late Sunday and Sunday night. Another upper
wave is expected to move across the lower Great Lakes toward the
middle of next week. The combination of increasing humidity and
instability along with upper support will lead to a return of warmer
temperatures and thunderstorm chances. Confidence in timing of the
greatest coverage is not great but current indications suggest
Monday into Tuesday would be the best time frame. 40-60% PoPs look
reasonable then. That said, there are signals that central Indiana
could be in the path of potential ridge riders, especially Wednesday
as the upper flow becomes more northwesterly as a dome of high
pressure expands north across the Plains.
Some locales could reach the lower 90s next week as the southerly
low level flow continues and the nearest cold front likely remains
northwest of the area.
&&
.AVIATION (00Z TAF Issuance)...
Issued at 727 PM EDT Wed Jul 24 2024
Impacts
- Thunderstorms exiting the area along with isolated MVFR Cigs.
- VFR Conditions return by 250200Z.
- MVFR fog possible overnight at LAF/HUF and BMG.
Discussion:
A cold front over Central Indiana was pushing south of the TAF sites
near 00Z. Radar shows decaying thunderstorms over central Indiana as
the advancing gust front has cut off access from the most favorable
air for TSRA development. Thus the decaying TSRA may be present at
BMG and IND for the first hour or so of the TAF period.
Thereafter, high pressure over the upper midwest will sag southward
into Indiana, providing mainly dry weather for Indiana tonight and
Thursday. HRRR suggests some TSRA redevelopment near HUF and the
lingering frontal boundary, but confidence is low for this and have
only included a VCTS mention for the moment.
High thin cloud is mentioned on Thursday due to possibly continued
smoke aloft, creating a thin veil.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Puma
SHORT TERM...Eckhoff
LONG TERM...MK
AVIATION...Puma
Area Forecast Discussion
National Weather Service Northern Indiana
555 PM EDT Wed Jul 24 2024
.KEY MESSAGES...
- Warmer, drier weather is anticipated through the weekend
with highs in the mid to upper 80s.
- Some Canadian wildfire smoke aloft may drift into the Great Lakes
region Friday and this weekend. No air quality concerns as of now
as the smoke is expected to remain aloft.
&&
.DISCUSSION...
Issued at 234 PM EDT Wed Jul 24 2024
Looking at GOES visible satellite imagery and the 15Z WPC surface
map, it is evident that the cold front has passed through most of,
if not all of, the CWA. Currently, the cold front is draped from
Peoria, IL to Marion, IN to Toledo, OH. Have significantly decreased
PoPs for much of the area today as the front went through faster
than expected in previous forecasts. As the attendant upper level
trough pivots through today, a few showers will be possible this
evening and overnight south of US 24. CAA filters in behind the
aforementioned frontal boundary, with more comfortable humidity and
lows dropping into the upper 50s tonight.
Tomorrow, another area of high pressure settles in across the Great
Lakes region from Canada. Late week and through the weekend will be
dry and less humid as this area of high pressure sticks around
through Saturday. As ridging builds across the central CONUS and
edges eastward, temperatures will warm throughout the weekend into
the upper 80s to near 90.
Wildfire smoke from active wildfires in the northwestern US and
western Canada remains aloft over much of Canada and the central US.
The HRRR and RAP both depict a plume of wildfire smoke to move south
over the Great Lakes region by Friday morning. This smoke should
mainly stay aloft, but it will result in a hazy appearance of the
sky and potentially a colorful sunset tonight. As of now, there are
no air quality concerns for the weekend.
As the ridge moves to the east, areas of weak to moderate mid level
vorticity combined with dominant southwesterly flow will help to
advect increased moisture towards our area. As a result, dewpoints,
cloud coverage, and rain chances will likely begin to increase into
early next week. One or more rounds of thunderstorms could develop
during the Monday to Wednesday timeframe and ride the periphery of
the weakening ridge. Humidity will increase alongside temperatures,
with highs in the upper 80s to low 90s by early next week.
Going into Tuesday and Wednesday, models seem fairly confident in a
more robust trough of low pressure moving over the Great Lakes. This
will also help to increase rain chances into the middle of next
week, especially on Tuesday. Although there is large uncertainty
this far out, there are early indications that there may be a better
chance for severe weather with this feature. At the very least,
temperatures look to remain well into the 80s with dew points in the
upper 60s and lower 70s through the middle of next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 555 PM EDT Wed Jul 24 2024
Post frontal drying will quicken near term in tandem with building
incoming high pressure across the lakes. Thus VFR conditions assured
through this period as broad sfc ridge takes hold.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Johnson/Ainsworth
AVIATION...T
Area Forecast Discussion...UPDATED
National Weather Service Memphis TN
1003 PM CDT Wed Jul 24 2024
...New UPDATE...
.UPDATE...
Issued at 1002 PM CDT Wed Jul 24 2024
Showers have all but dissipated over the Midsouth at mid to late
evening. Additional scattered showers may move into north MS
overnight, though their depiction by the HRRR is probably over-
done. GOES IR and water vapor imagery show little in the way of
upstream energy over east TX into the Arklamiss, and regional VAD
wind profiles and model-based time height profiles show no signs
of warm advection developing.
PoPs were reduced and thunder removed in an earlier forecast
update. Main overnight concern remains patchy fog potential where
skies partially clear.
PWB
&&
.SYNOPSIS...
Issued at 235 PM CDT Wed Jul 24 2024
Wet conditions and below normal temperatures will continue through
the week. Temperatures will be on the rise to near normal
conditions this weekend into early next week.
&&
.DISCUSSION...
(This evening through next Tuesday)
Issued at 235 PM CDT Wed Jul 24 2024
A deep trough over the Great Lakes extends southwards to near Dallas
Fort-Worth. The trough, aided by the sub-tropical jet, has pushed
series of disturbances to the Mid-South for the last few days. This
trend will continue until the trough can clear the area this
weekend. Daily showers and thunderstorm chances are possible each
day, with greatest chances (40-60%) along and south of I-40. Due
to the abundance of moisture and inversions depicted on
deterministic soundings, patchy to locally dense fog will be
possible each evening, especially in rural and low-lying areas
near bodies of water.
A positive side to shower and thunder chances each day means
additional cloud cover to keep temperatures below normal (in the
80s) until the trough moves and high pressure builds. Another
positive note, typical summer time pattern will keep shear on the
lower end so severe thunderstorm development is unlikely. A few
strong diurnally driven thunderstorms cannot be ruled out. QPF for
the remainder of the work week is a little over an inch for the
aforementioned area and less elsewhere. Locally higher amounts are
possible, particularly due to PW values in the 90th percentile and
higher (around 2" each day). Flooding may be the primary concern as
more rounds of rain are forecasted on top of saturated soils.
Temperatures will begin to warm up back into the upper 80s and
lower 90s this weekend into early next week as ridging builds in.
DNM
&&
.AVIATION...
(00Z TAFS)
Issued at 631 PM CDT Wed Jul 24 2024
Lower ceilings have dissipated across TAF sites as of 00Z
discussion. Potential exists for development of patchy fog and
subsequent lower ceilings overnight towards sunrise. Latest high
resolution probabilistic guidance is a bit more optimistic with
little if any reductions in visibilities and ceilings compared to
operational guidance. Leaned towards a persistence forecast but
may need to make adjustments if 00Z probabilistic guidance
continues the same trend with VFR conditions. Scattered showers
are possible again on Thursday but confidence/coverage of
thunderstorms remains too low to include in this TAF set.
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
PUBLIC FORECAST...DNM
AVIATION...CJC
Area Forecast Discussion
National Weather Service Morristown TN
855 PM EDT Wed Jul 24 2024
...New UPDATE...
.UPDATE...
Issued at 831 PM EDT Wed Jul 24 2024
Widespread stratiform mostly light rain will likely dissipate
over the next few hours. Another round of heavy showers and
isolated thunder is likely later tonight after midnight as a vort
max moves through. This round will continue into the morning
hours. The best chance for rain will be in the Southern Tennessee
Valley and along the East Tennessee Mountains. Some localized
flooding issues will be possible particularly in Southeast
Tennessee and Southwest North Carolina, where rain totals for the
last 24 hours are high. No changes were made to the forecast for
tonight.
&&
.SHORT TERM...
(This evening through Thursday)
Issued at 254 PM EDT Wed Jul 24 2024
Key Messages:
1. Periods of showers and a few thunderstorms remain possible
while temperatures remain seasonally cool through the short term.
Discussion:
Upper troughing with a southwest to northeast oriented H3 jet of 85-
100kts remains placed over the Ohio Valley region. Lobes of
vorticity and upper level divergence associated with the right
entrance region of this jet are working with weak surface
convergence to develop numerous to widespread showers across
portions of Tennessee into northern sections of our bordering Gulf
States. CAM guidance generally depicts a lull in activity late
this evening to just after midnight followed by an additional
uptick in activity with a secondary shortwave/vort lobes during
the overnight hours into Thursday morning. Thursday morning into
Thursday afternoon trends suggest that the greatest precip chance
will generally be south and east of the I-40 & I-81 corridors.
SPC Mesoanalysis and RAP soundings depict MLCAPE will remain around
700J/kg or less through this period, which will act to limit precip
efficiency and overall threats with this activity. However, given
recent rains saturating soil and potential training of storms that
may produce upwards of 1" hour rain rates, very isolated flooding
cannot be totally ruled out. Believe the low probability wording in
the HWO is good and will continue to roll with that. Temperatures
will remain slightly below seasonal normals through the period.
&&
.LONG TERM...
(Thursday night through next Wednesday)
Issued at 254 PM EDT Wed Jul 24 2024
Key Messages:
1. Chances for showers and storms during the entire period, but less
coverage is expected across the north Friday into Saturday.
2. High temperatures should be near to a bit below normal.
Discussion:
Models continue to show an overall moist pattern for the long term
period. We start the period Thursday night with an upper trough over
the Great Lakes region and upper ridging to our southeast and also
to our west. The upper ridge will build east during the weekend then
flatten out and retrograde to our southwest as another upper trough
digs into the eastern US late in the period. No big airmass change
is expected through all of this, but some limited drying is
currently expected to work in early in the period especially north
which may bring less convective coverage Friday into Saturday
across at least the north.
Overall we will see chances for showers and thunderstorms throughout
the extended period. Right now the highest chances look to be Sunday
and especially Monday/Tuesday as the upper ridge is replaced by
troughing. High temperatures are generally expected to run near to
slightly below normal.
&&
.AVIATION...
(00Z TAFS)
Issued at 720 PM EDT Wed Jul 24 2024
Showers will persist for most of the TAF period. Some clearing
will begin tomorrow afternoon. Most showers have been too low to
produce lightning today and that trend will likely continue. Any
thunder will be isolated. MVFR CIGs are likely tonight and some IFR
is possible especially near TRI. With showers and rain continuing
through the morning hours, CIGs will be slow to lift.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 71 83 71 85 / 50 60 20 50
Knoxville McGhee Tyson Airport, TN 70 83 70 84 / 60 60 20 50
Oak Ridge, TN 69 83 69 84 / 50 60 20 50
Tri Cities Airport, TN 68 81 68 84 / 60 60 20 30
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SHORT TERM...KRS
AVIATION...McD
Area Forecast Discussion
National Weather Service Reno NV
1246 PM PDT Wed Jul 24 2024
.SYNOPSIS...
* Thunderstorms will bring another round of locally heavy rain
and flash flood potential along with strong outflow gusts
through early this evening.
* Storms become more isolated over west central NV Thursday and
Friday with dry conditions for the weekend.
* Gusty southwest winds and more seasonal temperatures return
Thursday and Friday with locally critical fire weather
conditions.
&&
.DISCUSSION...
* Another round of storms this afternoon, again favoring the eastern
Sierra of Mono County into western NV with more isolated activity
from the Tahoe Basin into northeast CA. PWATs are up a bit this
morning with the 12Z KREV sounding showing 0.95" while mid level
winds/shear have increased - forecast soundings show S/SW winds 20-
35 kts at 500 MB this afternoon, strongest across northern areas.
Storms will again be capable of very heavy rain rates of 2-3"/hr
like the past couple of days with an isolated storm or two
exceeding 3"/hr. Rainfall rates of this magnitude may result in
localized flash flooding, especially near steep terrain. Also,
given the increased shear, storms will be a bit more organized,
capable of one inch hail and wind gusts in excess of 55 mph.
* Much drier air works into the region Thu-Fri with increasing
southwest winds. Enough moisture and instability will remain
across the Basin and Range Thursday and now it looks like Friday
as well, as some model scenarios show a negatively tilted
shortwave moving inland a bit farther south on Friday. Friday
is not a done deal as a few solutions are farther north with
this feature. However, confidence is high enough to introduce
isolated storms roughly along and east of the Hwy 95 corridor.
Storms will generally be faster moving and this may be a concern
for additional dry strikes. Winds will increase Thursday
afternoon and bring periods of choppy lakes and increase fire
weather concerns. Strongest winds will be Thursday, highlighting
areas north of I-80 where gusts across lower valleys will
exceed 30 mph. Breezy conditions persist Friday and expand to
much of the eastern Sierra, but speeds look to be a bit less
with overall gusts 25-30 mph.
* Otherwise, the good news is we will be cooling back to near
seasonal averages with more typical winds and an absence of
storms this weekend and early next week. There are indications
of another trough grazing us to the north Tue-Wed next week, but
its main impacts will be to keep our temperatures from heating
back up too fast and maybe bring an uptick in breezes near the
Oregon border.
Hohmann
&&
.AVIATION...
* Thunderstorms will again be the primary threat this afternoon and
early evening, mainly between 20-04Z although favoring the earlier
hours for the Sierra/Tahoe terminals, and the later hours for west
central NV. Periods of heavy rain could bring MVFR conditions
while lightning and outflow wind gusts of 35+ kt are more likely
with storms across lower elevations of western NV where some
blowing dust could reduce visibility to IFR/LIFR conditions at
airports like KLOL-KNFL.
* A drier pattern returns from Thursday onward with isolated
cells/outflow winds hanging on along the US-95 corridor (KLOL-KNFL-
KHTH) for Thursday/Friday. SW-W winds increase each afternoon
Thurs-Fri with gusts 25-30 kt across most of the main terminals.
Hohmann
&&
.FIRE WEATHER...
* Smoke from the Mill fire SW of Portola is most likely to spread
across eastern Plumas/southeast Lassen counties and parts of
western NV each afternoon through Friday. The HRRR smoke
trajectory model is keeping most of the smoke plume north of the
Reno-Sparks urban area for the next couple of days, affecting
areas around Pyramid Lake and extending into Pershing and
Churchill counties. This trajectory assumes similar smoke output
and no disruptions from t-storm outflows.
* Thunderstorms today will be mainly wet, but isolated dry strikes
are again a risk for parts of northeast CA-northwest NV where
storm motions will be faster and sub-cloud moisture isn`t quite as
abundant.
* For Thursday-Friday, thunderstorm chances decrease but a drier air
mass combined with increasing SW winds will produce areas of
critical fire weather conditions, especially for northeast CA and
northwest NV where a red flag warning is now in effect for
Thursday. Recent/ongoing fires and additional lightning holdovers
in these areas are at risk for more rapid fire spread as winds
increase. South of the warning area, isolated lightning fire
ignitions that aren`t extinguished by rain are also at risk for
increased spread rates with the drier and breezy conditions
Thursday-Friday. MJD/Hohmann
&&
.REV Watches/Warnings/Advisories...
NV...Red Flag Warning from 1 PM to 9 PM PDT Thursday NVZ458.
Flood Watch until 8 PM PDT this evening NVZ001-003.
CA...Red Flag Warning from 1 PM to 9 PM PDT Thursday CAZ270-278.
Flood Watch until 8 PM PDT this evening CAZ073.
&&
$$
Area Forecast Discussion
National Weather Service Tallahassee FL
732 PM EDT Wed Jul 24 2024
...New AVIATION...
.NEAR TERM...
(Through Thursday)
Issued at 356 PM EDT Wed Jul 24 2024
Deep layer southerly flow veers to the southwest on Thursday with a
weak surface trough setting up over the region. Latest RAP analysis
shows PWAT ranging from 2.0-2.5 inches across the region. The cloud
layer flow is generally south around 10 kts. Slow moving activity is
producing impressive rainfall rates, including portions of northern
Walton County, with MRMS showing up to 4"/hour, where a FLash Flood
Warning was recently issued. Localized flash flooding will be the
main concern this evening. In addition, Wind gusts around 40 mph are
possible due to water loading of downdrafts, especially with the
activity in Southwest GA and the FL Big Bend, where lapse rates in
the zero to 3 km layer are steeper. Activity will gradually diminish
between sunset and midnight.
On Thursday, a saturated air mass remains in place with PWAT nearing
2.5 inches. In addition, a quasi-stationary frontal boundary is
progged from the FL Panhandle into Southwest GA. Where this feature
sets up will determine the highest rainfall amounts. In general, PoPs
are around 80% across much of the region, except the Southeast FL
Big Bend and roughly northwest of an Albany to Defuniak Springs line.
The main concern again on Thursday will be the potential for flash
flooding, given the anomalously moist air mass, frontal boundary,
and slow storm motions. Some of the CAMs indicate localized rainfall
amounts of 4-6 inches, which will be highly dependent on where the
boundary sets up. Similar to today, gusty thunderstorm winds are
again possible.
Lows will be in the 70s with highs in the upper 80s to lower 90s.
&&
.SHORT TERM...
(Thursday night through Friday night)
Issued at 356 PM EDT Wed Jul 24 2024
Wet weather remains the name of the game thanks to a persistently
moist airmass presiding over the region. Elevated PoPs are kept in
the short-term forecast as a nearby upper trough to our NW slowly
pivots northeastward. Therefore, heavy rain capable of nuisance or
flash flooding will continue to a concern. The abundant cloud cover
combined with widespread precipitation should keep high temperatures
around the low 90s (isolated upper 80s). Overnight should be in the
mid 70s away from the immediate coast.
&&
.LONG TERM...
(Saturday through Tuesday)
Issued at 356 PM EDT Wed Jul 24 2024
Ridging builds over the region this weekend as the stubborn upper
trough finally gains more latitude. Therefore, a temporary reverting
to at least somewhat of a normal summertime convective pattern
appears likely into early next week. However, guidance continues to
show the ridge retrograde west while the northern stream trough
slips south and accompanied by a backdoor front. This pattern shift
should increase our rain chances the latter part of the long-term
period. Just beyond mid-week, global models suggest an MCS may dive
into the Lower MS Valley on the heels of NW flow aloft. This
potential evolution bears watching. Upper 80s to low 90s are
forecast for highs while overnight lows remain in the sultry 70s.
&&
.AVIATION...
(00Z TAFS)
Issued at 728 PM EDT Wed Jul 24 2024
A bit of a messy taf period is expected with showers and
thunderstorms lingering across the region later into this evening.
Another round will be possible near the coast early in the
morning, most likely affecting KECP but potentially KTLH as well.
Additional showers and storms are expected across the entire area
throughout the day tomorrow. Low clouds may be possible at KDHN
and KABY in the predawn hours, but confidence is low at this
point. Otherwise, VFR conditions are expected outside of
convection.
&&
.MARINE...
Issued at 356 PM EDT Wed Jul 24 2024
The main boating concerns over the next few days are daily
chances for thunderstorms capable of gusty winds, locally high seas,
frequent lightning, and potential waterspouts. Otherwise, mainly
light south winds prevail with seas of 1 to 2 feet through the
weekend. By early next week, winds appear to become more easterly.
&&
.FIRE WEATHER...
Issued at 356 PM EDT Wed Jul 24 2024
Wet weather driven by a very moist airmass makes for minimal fire
concerns over the next 3 days. Widespread wetting rains from
scattered to numerous showers and thunderstorms are likely today and
tomorrow. Gusty and erratic winds with frequent lightning are
expected within or near any convection.
&&
.HYDROLOGY...
Issued at 356 PM EDT Wed Jul 24 2024
Heavy remains a concern over the next few days as a wet pattern
persists into the weekend. Pockets of very high rain rates have
already been observed this afternoon that has likely produced
isolated flooding. Additional flooding is possible through this
evening with renewed potential tomorrow as the airmass remains
very moist. Looking ahead, we may have a brief relative reprieve
this weekend, before rain chances ramp back up early next week
ahead of an apparent backdoor front dropping in from the north. At
least a Marginal Risk (level 1 of 4) is outlined for much of the
region in the Days 1-5 Outlooks by the WPC. Rises in some local
area rivers may occur depending on where the axis of heaviest
precipitation sets up.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur by calling the office or tweeting us @NWSTallahassee.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 75 89 75 90 / 30 80 40 80
Panama City 77 90 77 88 / 50 70 40 60
Dothan 74 89 73 90 / 50 70 50 60
Albany 74 89 74 90 / 40 90 50 60
Valdosta 75 91 74 91 / 40 70 50 70
Cross City 74 92 75 91 / 40 70 30 70
Apalachicola 79 89 79 87 / 50 80 50 60
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...LF
SHORT TERM...IG3
LONG TERM....IG3
AVIATION...Merrifield
MARINE...IG3
FIRE WEATHER...IG3
HYDROLOGY...IG3
Area Forecast Discussion
National Weather Service Tucson AZ
216 PM MST Wed Jul 24 2024
.UPDATE...The Storm Prediction Center has issued a Severe
Thunderstorm Watch until 9 PM MST for portions of Southeast
Arizona including Pima, southeast Pinal, Graham and Santa Cruz
counties.
&&
.SYNOPSIS...
Daily chances for showers and thunderstorms are expected through
this week into this weekend with the main threats being strong gusty
winds and heavy rainfall.
&&
.PREV DISCUSSION... /issued 151 PM MST Wed Jul 24 2024/
It`s shaping up to be an active afternoon and evening across
southeast Arizona as our area is under a favorable flow pattern
with the necessary moisture to result in showers and
thunderstorms. With the high to our northwest, we`ve got 10-15 kts
of mid level NE steering flow to help push convective development
now over the White Mountains into the lower elevations later this
afternoon into this evening. Latest SPC RAP mesoanalysis shows
MLCAPE of 500-1500 J/KG with 1500 J/KG of DCAPE to support strong
winds. Moisture levels east of Tucson aren`t quite as high with
PWAT values at or just above 1 inch, so SBCAPE values are in the
250-500 J/KG across much of Cochise COunty. Outside of the
convection coming off the White Mountains, latest visible
satellite shows a cumulus field developing across much of the
area, so additional showers and thunderstorms are expected in
advance of the push from the White Mountains. SPC has most of
Pima, Pinal and Santa Cruz Counties in a slight risk for severe
thunderstorms. The gusty outflow winds may result in areas of
blowing dust, thus a Blowing Dust Advisory remains in effect from
4 PM to 11 PM. Additionally, flash flooding is a threat,
especially from Tucson westward into the T.O. nation where deeper
moisture is in place as PWAT values are 1.3"-1.7" west of Tucson.
Convective activity will tend to wind down later this evening.
A very similar flow pattern is in place for Thursday and the
HREF/CAMs are showing an active day, especially for
Graham/Greenlee/Cochise County which may not get hit as hard today
to work the atmosphere over. Confidence is a bit lower from Tucson
westward since the atmosphere may be more worked over in these
locales, especially if today turns out to be a big day. SPC has
already outlined our area in a marginal risk for severe
thunderstorms for Thursday and that looks good.
The mid/upper level high will start to wobble a bit more to the
south Friday which will turn the flow more northerly. Deep moisture
levels remain in place with PWAT values ranging from 1.25" to 1.75"
across the region to continue our active monsoon period. As the high
continues to nudge south and east this weekend, that will tend to
push the best chances for showers and thunderstorms from Tucson
south and eastward. By early to mid next week, the high will shift
into New Mexico that will shift out flow pattern to come more from
the east to southeast. Some indications of an inverted trough early
next week as well that could help ramp up activity as well.
Temperatures during the forecast period will be about 3 to 6 degrees
above normal.
&&
.AVIATION...Valid through 26/00Z.
SCT-BKN clouds AOA 8-10K FT MSL until 25/06Z then again aft 25/18Z.
Another round of scattered to numerous SHRA/TSRA expected to develop
and impact much of the forecast area moving from the NE of the fcst
area to SW now thru 25/11Z then again 25/20Z thru the end of the
period. Strong winds to 50-60 kts possible near TSRA. Outside of
TSRA, surface winds will generally be easterly/southeasterly and
remain under 10 kts. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...
Scattered afternoon and evening showers and thunderstorms with day
to day variability on which areas will see the best chance of
rainfall. Today through Friday is looking particularly active at
this time, with each day having the threat of heavy rain, localized
flash flooding and strong gusty winds. Minimum relative humidities
will be 20 to 30 percent in most lower elevation locations and 25 to
40 percent in mountain areas. Away from thunderstorms, 20-foot winds
will generally be 15 mph or less, with afternoon/early evening gusts
to 20-25 mph and light winds overnight.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
Severe Thunderstorm Watch until 9 PM MST for
AZZ501>507-509>511-513>515. (This includes Pima, southeast Pinal,
Graham and Santa Cruz counties)
Blowing Dust Advisory until 11 PM MST this evening for
AZZ502-504-505.
&&
$$
Public...Public Forecaster
Aviation...Aviation Forecaster
Fire Weather....Fire Weather Forecaster
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