Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/25/24
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
303 PM AKDT Mon Jun 24 2024
.SYNOPSIS...
A very active pattern will bring the warmest temperatures so far
this Summer to much of the Interior on Wednesday and Thursday
while a highly unusual Bering Sea low pressure system brings near
Gale force winds to the Yukon Delta coast on Wednesday. The heat
wave will even extend to the North Slope on Wednesday and
Thursday, bringing near record high temperatures to that area.
Thunderstorms will continue to be active this week, with
relatively dry thunderstorms possible east of Chena Hot Springs
on Wednesday evening.
&&
.DISCUSSION...
Analysis and Model Discussion...
An amplified and impactful 500 mb pattern is set to impact
northern Alaska over the next week. Ridging persists over most of
the area with a tight closed low just north of Utqiagvik north of
the Arctic Coast. This low will retrograde northward, opening the
door for even stronger ridging to build into the Interior and even
north to the Arctic Coast. This will bring high temperatures nearing
or exceeding 90 degrees to much of the Interior on Wednesday and
Thursday. 80s are even expected north of the Brooks Range
approaching the Arctic Coast. Adequate 850mb temperatures in the
upper-teens C over many areas look to further support this warmth in
addition to the aforementioned and mostly clear skies. By Wednesday
morning, a tight and powerful vertically stacked closed low will move
to near St. Paul Island. This feature is highly anomalous for this time
of year, and models are progging it at 3-4 standard deviations from
normal. This feature will bring near Gale force south and southeast
winds to the Yukon Delta on Wednesday morning and 20 mph south
and southeast winds south of the Bering Strait. This will bring even
more rare elevated surf to the region for this time of year Wednesday
through Friday.
As the low transits northward on Thursday and Friday, a sharp
boundary looks to form from the Northwest Arctic Coast to the central
Alaska Range. This boundary looks to be the focus for highly active
thunderstorm activity. A shortwave also looks to bring elevated
thunderstorm activity and the possibility of dry thunderstorms
east of Chena Hot Springs on Wednesday evening.
Models are in quite excellent agreement through late work-week.
Central and Eastern Interior...Hot and dry will be the main story
through the work week with isolated thunderstorms and a few areas
of widely scattered thunderstorms. Highs will reach into the low
80s Monday and Tuesday and into the mid to upper 80s with some 90s
possible on Wednesday and Thursday. Adequate 850mb temperatures
in the upper-teens C over many areas look to further support this warmth.
Highs will likely remain in the 80s through the weekend. Lows in many
locations will struggle to drop below 60. Thunderstorms will be isolated
tomorrow, except widely scattered over the Fortymile Upland and near
Eagle. On Wednesday, a shortwave looks to rotate around the high and
possibly spark off widely scattered thunderstorms over the eastern Alaska
Range and Fortymile Uplands east of Chena Hot Springs. These
thunderstorms look to possibly be mostly dry in nature. For the Fairbanks
area, smoke from the wildfires burning in the Tanana Flats has
marginally improved this afternoon. It is expected to become
dense, once again, starting late this evening / overnight. Then,
it is expected to last through tomorrow night. Dense smoke
conditions should improve a bit by late Wednesday morning. Todays
overall smoke distribution pattern is primarily due to the winds
shifting to westerly this afternoon and back to southerly/southeasterly
late this evening / overnight and lasting into Wednesday morning.
The HRRR Smoke model picks up on this pattern quite well. So, we
went with that for the timing. It looks like it may even be more
dense tonight into tomorrow as the model is picking up on values
up to around 1,000 and nearing 1,500 for a few spots for that
timeframe.
West Coast and Western Interior...Strong ridging over the Interior
and the influence of the low in the Bering Sea over the West Coast
will create a mix of conditions over the area over the next week. As
the low moves north, expect near Gale force winds and some rain along
the Yukon Delta coast on Wednesday. In the Interior, highs will be
in the mid 70s to lower 80s under mostly sunny skies with areas of
smoke near active fires, with temperatures trending upwards
through Wednesday. Lows will also get warmer each day through
Thursday. Thunderstorms will be widely scattered near McGrath this
afternoon and from McGrath to Lake Minchumina on Tuesday. Storms
will be isolated across the rest of the Interior on Tuesday.
Wednesday and Thursday look to bring additional isolated
thunderstorms.
North Slope and Brooks Range...The patchy fog and low stratus along
the coast from this morning will becoming less and less extensive the
next couple of nights as the closed low aloft moves offshore and
is replaced with ridging. Temperatures will rise each day, with a
full on North Slope heatwave expected starting Wednesday. Highs
will be in the 80s inland, with 60s and 70s along the coast
Wednesday and Thursday. Strong thunderstorms are possible Thursday
over the western Brooks Range. Otherwise, thunderstorms will be
isolated over the eastern Brooks Range each afternoon. Notably, portions
of the North Slope look to be only 2 to 3 degrees below record high
temperature criteria for the Wednesday and Thursday timeframe.
Coastal Hazard Potential Days 3 and 4...The aforementioned low
pressure system in the Bering Sea will bring elevated surf 1 to 3
feet above the normal high tide line along the Yukon Delta coast
as well as south facing shorelines south of the Bering Strait
including Nome. Water will be elevated Wed-Fri with multiple water
level peaks as storm surge values remain fairly constant and tides
go in and out.
&&
.FIRE WEATHER...
Fire weather continues to be a concern with hot and dry conditions
and active thunderstorm days all in the forecast. Today, expect
highs in the mid 70s to low 80s across the Interior. RHs will
reach critical values (<25%) east of Delta Junction. Winds will remain
light. Tuesday will be a few degrees warmer yet, though RHs will
generally remain above critical values. Wednesday and Thursday are
the real scorchers with highs nearing 90 and min RHs 20-25% east of
Tanana. Could see Red Flag or near Red Flag conditions for
hot/dry/windy conditions for Thursday and Friday east of Galena.
Otherwise, winds will remain below 15 mph.
Thunderstorms will be active each day this week. This afternoon, expect
widely scattered thunderstorms from McGrath south to the Western
Alaska Range and isolated thunderstorms elsewhere south of the
Brooks Range and east of Ruby. Tuesday will see widely scattered
thunderstorms from McGrath to Minchumina and over the Fortymile
Uplands with isolated storms across the rest of the Interior and
eastern Brooks Range. Wednesday will feature widely scattered
thunderstorms across the eastern Alaska Range and Fortymile
Uplands. These storms look to be drier in nature under the strong
ridge. Isolated storms are expected across the rest of the Interior on
Wednesday. Thursday and Friday have the potential to be big lightning
days, with most of the activity focused on the boundary between the
ridge and the influence of the low in the Bering Sea.
&&
.HYDROLOGY...
Recent heavy rains have led to higher water levels along the
Fortymile River, but drier conditions expected over the next
several days will allow water levels to recede this week.
Glacial fed rivers including the Tanana may begin to rise as
warming temperatures lead to increased high elevation snowmelt.
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Dense Smoke Advisory for AKZ839-840.
Dense Smoke Advisory for AKZ844.
PK...Small Craft Advisory for PKZ850.
&&
$$
Area Forecast Discussion
National Weather Service Cleveland OH
1019 PM EDT Mon Jun 24 2024
.SYNOPSIS...
Low pressure will slide east through the Great Lakes tonight
into Tuesday, lifting a warm north north across the area Tuesday
afternoon. A cold front will then move east through the region
on Wednesday, followed by high pressure by the end of the week.
Another low pressure system system is expected to move across the
region on Saturday.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
930 PM Update...
The forecast for this evening remains on track and no changes
were needed with this update. The convection over southern
Wisconsin will stay to the west of the CWA and the complex over
northern Minnesota will be the activity to monitor overnight as
it likely moves southeast. The area will likely be at least
clipped by this complex Tuesday morning, but there`s still
uncertainty in how much instability is in place and how much the
MCS weakens by daybreak.
Previous Discussion...
Surface high pressure and upper- level troughing will exit east
of the region as an upper- level ridge builds across the Great
Lakes tonight into Tuesday. Beneath the ridge. very steep mid-
level lapse rates will be advected northeastwards across the
Upper Midwest and Great Lakes region tonight into Tuesday,
resulting in strong instability, but also strong capping.
An upper-level trough across northern ND/MN this evening will
provide sufficient forcing for an organized complex of
thunderstorms to develop and move southeastward through the
Great Lakes overnight into Tuesday morning. Confidence is
increasing in at least some elevated convection arriving across
northern OH Tuesday morning. Will need to monitor upstream
convective trends, particularly later this evening and overnight
as any storms that are able to become surface-based would have
the potential for damaging wind gusts. There is also a
concerning signal for the HRRR late Tuesday morning behind the
convection for the potential of a wake low to produce strong
wind gusts. This potential is low, but possible, given the
expectation of a rapidly-decaying MCS and warming cloud tops.
Otherwise, anticipating much of Tuesday afternoon and evening to
be relatively quiet as morning convection combined with an elevated-
mixed layer should result in strong capping and inhibit
initiation. If this outcome holds true, high temperatures
should break unto the upper 80s to lower 90s under diminishing
cloud cover.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Cold front will be in the process of progressing southeast across
the region to begin the short term period. Showers and thunderstorms
along this cold front will continue to move through the region with
the potential for any strong to severe storms dependent on how the
environment evolves with any storms that occur Tuesday and Tuesday
night. High pressure will quickly build over the region behind the
cold front which will end any remaining showers and storms and clear
out cloud cover for Thursday.
Near normal high temperatures on Wednesday in the upper 70s to mid
80s across the region. Lows will settle in the upper 50s to lower
60s Wednesday night. Cooler behind the cold front by Thursday with
highs in the mid 70s to lower 80s. Northerly flow with a clear sky
Thursday night will allow for lows to dip in to the low 50s across
Northeast Ohio and Northwest Pennsylvania. Slightly warmer in the
mid to upper 50s west of the I-71 corridor.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
High pressure remains overhead to end the work week before we
undergo another unsettled period this weekend. We`ll be dry to begin
Friday with PoPs increasing Friday afternoon and evening from west
to east. Warm front lifts northeast bringing showers and the
potential for some strong to severe storms to the region through
Saturday. Cold front will cross east Saturday night into Sunday
morning followed by high pressure which will allow us to end the
long term period fairly dry.
Temperatures will gradually warm through the first part of the long
term with the warmest day of the period occurring on Saturday as the
warm front lifts through the region. High temperatures in the upper
80s to lower 90s are possible Saturday before they return closer to
normal behind the cold front Sunday and Monday.
&&
.AVIATION /00Z Tuesday THROUGH Saturday/...
VFR is expected for the majority of the TAF period, however
uncertainty still exists in the forecast for Tuesday morning
and afternoon. A complex of thunderstorms will likely develop
somewhere over the Upper Midwest this evening before tracking
southeast across the Great Lakes region overnight and possibly
moving over the area Tuesday morning. Will need to monitor the
development of convection over the next several hours, as there
is quite a bit of uncertainty in the track of the MCS. Opted to
maintain VCTS/VCSH in the TAFs for the time being, but will
likely make adjustments as confidence increases over the next 12
hours or so. Any storms that move directly over terminals could
produce non-VFR conditions and possible brief gusty winds. Rain
chances should decrease during the afternoon.
Winds become light and variable tonight before becoming
south/southwest later tonight into Tuesday morning and
increasing to 10 to 15 knots with gusts to 20 to 25 knots by
late morning or early afternoon.
Outlook...Non-VFR possible in showers and thunderstorms Tuesday
evening through Wednesday. Non-VFR possible again in showers and
thunderstorms on Saturday.
&&
.MARINE...
High pressure begins to exit eastward tonight and allows a warm
front to sweep northward across Lake Erie. Variable winds around 5
to 10 knots become southerly and increase to 15 to 20 knots as the
warm front moves across the lake. On Tuesday, southerly to
southwesterly winds are expected to freshen further to about 15 to
25 knots as a potent low moves eastward through the James Bay region
and interacts with the western flank of the aforementioned ridge
over/near Lake Erie. The southerly to southwesterly winds are
expected to be strongest west of Vermilion. Accordingly, a Small
Craft Advisory has been issued for nearshore waters from Maumee Bay
to Vermilion from 8 AM to 5 PM EDT Tuesday. The limited fetch will
result in waves of mainly 3 feet or less in nearshore waters, but
waves as large as 4 feet are expected along/near 5 nautical miles
offshore. Waves as large as 3 to 6 feet are expected in open U.S.
waters. Southwesterly to westerly winds ease to around 10 to 15
knots Tuesday night as the aforementioned ridge continues to exit
eastward and the aforementioned low weakens/moves farther eastward.
Waves subside to 3 feet or less by daybreak.
On Wednesday, the low will move toward Labrador and drag a cold
front eastward across Lake Erie. The cold front passage will cause
winds around 10 to 15 knots to become more westerly and then
northwesterly by late Wednesday night as waves remain 3 feet or
less. Behind the cold front, high pressure builds from the Upper
Midwest and western Great Lakes through Friday before another warm
front sweeps northward across Lake Erie Friday night. On Saturday,
another cold front should approach from the west. Variable flow
around 5 to 15 knots is expected Wednesday night through Saturday as
waves remain mainly 3 feet or less. However, occasional 4 footers
are forecast in open U.S. waters on Saturday.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
NY...None.
MARINE...Small Craft Advisory from 8 AM to 5 PM EDT Tuesday for
LEZ142>144.
&&
$$
SYNOPSIS...Kahn
NEAR TERM...Kahn/Maines
SHORT TERM...Iverson
LONG TERM...Iverson
AVIATION...Maines
MARINE...Iverson/Jaszka
Area Forecast Discussion
National Weather Service Cheyenne WY
935 PM MDT Mon Jun 24 2024
.KEY MESSAGES...
- Moisture will return to the High Plains on Wednesday and
Thursday, leading to the potential for some strong
thunderstorms in the afternoon and evening.
&&
.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 340 PM MDT Mon Jun 24 2024
Gusty showers and thunderstorms continue across the CWA this
afternoon. Current radar trends depict widely scattered coverage of
these storms, most fairly week and unorganized. Still can`t rule out
the threat of severe gust to 60 MPH this afternoon. Earlier, an
observation site gusted 50 MPH due to a collapsing storm. Current
observations from across the CWA continue to show the very dry low-
levels, with most locations under 25 percent relative humidity. This
supports the strong wind threat. RAP soundings for this afternoon
show strong inverted-V profiles, DCAPE values over 1200 J/kg, and
very high based storms. All this to say, that strong winds in
storms is the primary concern this afternoon, although, cannot
rule out some small hail. Aside from the storms, hot
temperatures continue this afternoon, with areas in the Heat
Advisory and the panhandle spiking to 100 degrees and warmer
this afternoon. Temperatures should slowly be on the decline now
with increasing cloud cover from storms. Hi-Res guidance has
storms dissipating early this evening.
Looking at a quiet day on Tuesday, as the CWA sits under the broad
ridge over much of southern CONUS. A weak back door front dropping
down from the northeast with bring "cooler" temperatures to parts of
the CWA. Biggest cool down will be north of the North Platte River
Valley. Temperatures here will be about 10 degrees cooler compared
to Monday`s high, leading to highs in the upper 80s. Elsewhere,
temperatures will only drop by a few degrees. Should stay dry on
Tuesday, however, did add slight chance PoPs to the southern border
to account for some light showers that the HRRR is showing. Most
other Hi-Res guidance remains dry.
Wednesday will be much more active. As the ridge axis slides further
east, winds aloft will shift out of the southwest. This southwest
flow will allow the CWA to tap into monsoon moisture, increasing mid-
level moisture. At the surface, southeast flow will prevail, also
increasing moisture. As a result, model soundings and the NAEFS show
PWs generally over an inch east of the Laramie Range, which is above
the 90th percentile for climatological normal. An embedded shortwave
moving through the ridge will likely spark scattered convection
during the afternoon. Luckily, cloud layer winds are rather fast, so
storms will be quick moving, but dropping torrential rains. This
could lead to flash flooding concerns Wednesday afternoon into
Wednesday evening. Sufficient effective shear and veering with
height will also support the potential for more organized and
potentially severe convection.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 345 AM MDT Mon Jun 24 2024
The long term forecast period will start out on an active note with
a good chance for showers and thunderstorms on Thursday. By
Thursday the broad ridge over the southwestern CONUS will have
broken down with as a longer-wave trough moves throughout the
central and northern Rockies. This trough will spread faster
flow aloft eastward by later in the day. Lingering surface
moisture in southeastern Wyoming and western Nebraska will again
result in enough instability for showers and thunderstorms,
with 500b flow increasing to around 30-40 knots by 0z. However,
a primary difference in the Thursday forecast compared to
Wednesday looks to be surface and lower-level flow, which seems
light and muddled at best lending to straight/shorter hodographs
and thus more clustered/outflow dominant showers and storms.
Still, will have to watch the Thursday thunderstorm forecast as
several ingredients for severe weather remain in the vicinity of
the CWA.
On Friday, a frontal system will pass through the central High
Plains bringing a drier airmass with cooler temperatures for both
Friday and Saturday. Only a few isolated orographic showers look
possible on Saturday afternoon. By Sunday, expect temperatures to
rebound as height rise, however a dry airmass will remain in place
with only a few showers in the higher terrain of southeast
Wyoming.
&&
.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 932 PM MDT Mon Jun 24 2024
West flow aloft tonight will turn northwest on Tuesday. Clear
skies will prevail, except for occasional ceilings near
1500 feet at Chadron and Alliance from 13Z to 17Z. Winds will
gust to 25 knots at Cheyenne, Laramie, Rawlins, Scottsbluff and
Sidney from 15Z to 00Z.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...SF
LONG TERM...MAC
AVIATION...RUBIN
Forecast Discussion at weather.gov/mqt.
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...Small Craft Advisory from 11 AM to 9 PM CDT Tuesday for LSZ121-
140>148-150.
&&
$$
DISCUSSION...Rothstein
AVIATION...Rothstein
MARINE...Rothstein
Area Forecast Discussion
National Weather Service Grand Forks ND
1003 PM CDT Mon Jun 24 2024
.KEY MESSAGES...
- Severe thunderstorms may develop this afternoon into the
early evening. Should thunderstorms develop, damaging wind
gusts, large hail, and tornadoes will be possible.
- The next good chance for showers and storms looks to be
Thursday night into Friday.
&&
.UPDATE...
Issued at 1003 PM CDT Mon Jun 24 2024
Strong storms continue across portions of mainly northwest
Minnesota this evening. The cold front has progressed to the
southeast, with the best storm chances now along a line from
Fargo to Blackduck and areas to the south and east. The primary
risk through the remainder of the evening will be large hail up
to the size of ping pong balls.
UPDATE
Issued at 700 PM CDT Mon Jun 24 2024
Storms are now forming along and ahead of the cold front, with
the strongest activity stretching along a line from Baudette
southwestward to around Mayville. Guidance continues to show a
large degree of variation regarding the potential evolution of
future development; however, the best chances for severe storms
will continue to exist along the aforementioned line and cold
front. As of this update, there have been reports of up to golf
ball sized hail and a few funnel clouds. This risk is expected
to continue through much of this evening as the front slowly
pushes to the east and southeast.
&&
.DISCUSSION...
Issued at 241 PM CDT Mon Jun 24 2024
...Synopsis...
Really there is no change to the previous thinking, there is a
lot of uncertainty in how any additional storms storms may or
may not develop yet today. The first 700mb wave is located over
the Minnesota arrowhead. Another one may be showing up over
southeast North Dakota and northeast South Dakota, which will
slide into western Minnesota late this afternoon into this
evening. This area is pretty well capped, with 700mb
temperatures of +10C to +14C. At the surface, the weak low has
been holding over central to east central South Dakota, sliding
east. Again, this is in the capped area so far. There is a cold
front over this FA, which appears to be along a Langdon to
south central North Dakota line (somewhere between Bismarck and
Jamestown). There has been some weak cumulus forming along this
line. One storm about an hour ago between Bismarck and Jamestown
kind of fizzled, although it was in the capped region. Overall
it seems like storms should have a chance to fire across the
central and northern Red River Valley along this front, which
will cross into Minnesota by early evening.
...This afternoon into early evening...
The HRRR has been showing some weaker convection forming along
the cold front over the central and northern Valley late this
afternoon and early evening. By early evening, it develops a
complex of storms around the Twin Cities, which it then
transitions to a bowing line of storms as they move to the
east-southeast. There are other CAMs which still show storms
developing over the southern Valley into west central Minnesota
late this afternoon and early evening, which they eventually
track along the highway 10 corridor toward the Twin Cities this
evening. So will be watching these two potential areas (along
the cold front and from the southern Valley into west central
Minnesota) from now through early evening for convective
development. As for parameters along and ahead of the cold
front, temperatures have risen into the low to mid 80s over
northeast North Dakota with dewpoints in the low 70s. The SPC
meso page is showing SBCAPE values over 5000 J/kg with effective
shear around 35 knots. As for negatives for development along
the cold front, it is not really that strong (maybe more of a
dryline or trough) and there is no low level jet support in
this area. The low level jet should support any storms that take
off along the highway 10 corridor toward the Twin Cities.
...Thursday night into Friday...
Another fairly deep 700mb wave tracks into the Northern Plains
during this time frame, with all ensemble solutions showing a
fairly widespread footprint for convection. WPC did mention that
they may add a marginal risk for excessive rainfall up into this
area to cover this potential. Still a ways off, so will leave it
at that for now.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 635 PM CDT Mon Jun 24 2024
The primary impact to aviation this evening will be scattered
thunderstorms along a cold front stretching from Lake of the
Woods southwestward to around Cooperstown. Locations potentially
seeing VCTS or TSRA will be KTVF, KBJI, and KFAR primarily,
with lower chances at KGFK and KDVL. Otherwise, VFR conditions
prevail outside of thunderstorm activity with mostly clear skies
west of the cold front.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...Lynch
DISCUSSION...Godon
AVIATION...Lynch
Area Forecast Discussion
National Weather Service Northern Indiana
809 PM EDT Mon Jun 24 2024
.KEY MESSAGES...
- A line of thunderstorms is expected to move through late
overnight through early Tuesday morning bringing a chance for
locally strong/damaging winds.
- Confidence remains low on details regarding Tuesday
afternoon/evening showers and thunderstorms. If these develop,
large hail, damaging winds, and locally heavy rain will be
main threats.
- Seasonable temperatures and dry conditions expected Thursday
and Friday before additional rain chances return Saturday.
&&
.UPDATE...
Issued at 809 PM EDT Mon Jun 24 2024
Main focus remains on convective chances and intensity later tonight
into Tuesday morning as convection over MN/WI congeals into an
upscale growing MCS. The genesis of this is currently underway well
upstream over northern MN. Of note through is a separate area of
scattered convection north of a warm in srn MN and sw WI as of this
writing. The HRRR is starting to pick up on this and hints at
this elevated activity surviving east into the area between
7-11z as a corridor of strong low-mid level theta-e advection
overspreads the area from west to east. Bumped up PoPs during
this time to account for these trends, with this activity to
generally hold below severe limits. Attention then turns to the
upscale growing MCS and a possible bowing segment turning south
into the area between roughly 11-15z Tue AM. This activity does
outpace more favorable flow and instability with a trend toward
backbuilding and an outflow dominant line this far south,
though a wind threat (50-60 mph winds) definitely remains in
play across northern portions of the forecast area if a more
pronounced bowing segment is realized upstream over WI and Lake
MI.
&&
.DISCUSSION...
Issued at 250 PM EDT Mon Jun 24 2024
After our extended heat wave last week, we return to a more
active, complex weather pattern over the next 24-36 hours.
Convection currently in the Dakotas and MN will grow upscale and
evolve into a MCS as we head through the evening and overnight
hours. Overall agreement is for this complex to maintain
intensity through Wisconsin where the greatest instability will
reside, along with the stronger shear. A gradual weakening
should take place as it works its way southeastward across SE
Lake Michigan and Indiana where a rapid dropoff in overnight
instability will be located. Nevertheless, mesoscale maintenance
of the stronger cells may allow them to produce instances of
strong/damaging wind gusts as they push into our forecast area
and the updated Day 1 Outlook from SPC now drags a Slight Risk
(2 of 5) into North Central Indiana and Southwest Michigan. CAMs
have begun to latch onto this better as well, and given the 4mb
pressure rises on the HRRR as the MCV moves across the lake,
there is some concern for seiche activity along with an increase
in wave action and rip current risk leading into Tuesday. Some
closer evaluation of this will be needed as we head into the
overnight hours...
In the wake of the late overnight into early tomorrow morning
convective complex, steep low/mid level lapse rates and hot
daytime temperatures will contribute to rapid and intense
instability across the forecast area. Bulk shear will be
limited, ranging from 20-30kt, which will likely prevent a more
significant severe episode if anything develops (more below). A
corridor of low LCL heights will be favorable for a tornado
environment, however, we will need existing surface boundaries
to enhance low level helicity as this parameter looks meager.
It`s worth noting that confidence in triggers due to the
aforementioned earlier convection, and a lack of strong forcing
during the day, may keep a lid on afternoon thunderstorms
altogether. Therefore, at this time, confidence is very low in
Tuesday afternoon/evening severe potential. If anything does
develop, the thermodynamic profile will help to create robust
updrafts with a hail and damaging wind threat; we`ll just have
to see how the AM convection shakes out first.
Fortunately, the hottest day of the week will be tomorrow
before a frontal passage returns us back into more seasonable
temperatures. We will have dry days on Thursday and Friday
before another shortwave and surface front brings additional
chances for rain and storms.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 651 PM EDT Mon Jun 24 2024
VFR conditions and light winds will persist into the early overnight
on the back edge of stable high pressure. Chances for convection
(and associated brief vis/cig restrictions and gusty winds) then
enter the picture later tonight through early Tuesday afternoon as a
MCS likely develops southeast through WI and MI, with a trailing
outflow and incoming warm front allowing at least a broken/weakening
line of convection to drop south into northern IN, best chances in
the 12-16z window. Scattered elevated convection could even
develop in advance of the main line in roughly the 9-12z window,
though confidence in coverage and timing of convection remains
low as activity will outpace better flow and instability. Winds
will increase and back more to the west-southwest during the
day tomorrow otherwise.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...Small Craft Advisory from 2 AM to 2 PM EDT Tuesday for LMZ043-
046.
&&
$$
UPDATE...Steinwedel
DISCUSSION...Norman
AVIATION...Steinwedel
Area Forecast Discussion
National Weather Service Marquette MI
646 PM EDT Mon Jun 24 2024
.KEY MESSAGES...
- Line of thunderstorms moves through the forecast area tonight,
some storms could be strong to severe and produce damaging
winds and large hail.
- Tuesday will be the warmest day of the week with highs in the
mid 70s to mid 80s. Gusty winds to 30 mph are also expected,
especially over the Keweenaw.
- Next round of precipitation is expected Thursday night into
the weekend.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 143 PM EDT Mon Jun 24 2024
Current mesoanalysis across the region places an upstream shortwave
moving through northern Minnesota and a cold front tied to a surface
low moving through Lake Winnipeg not far behind. Precip associated
with this is trending down per DLH radar and GOES IR. To the south,
mid-level ridging extends across the Plains with subtle shortwaves
perturbations embedded atop. At the surface, a surface low was
observed moving across eastern South Dakota along with a
southeastward draped warm front and several surface troughs tied to
the mid-level perturbations. Across our forecast area, surface high
has allowed for clear skies to largely dominate; at the time of this
publishing though, high clouds streaming eastward into the region
associated with the shortwave pressing through Minnesota was
observed on GOES Vis imagery. With these mostly clear skies and
predominately southerly flow, daytime temps have warmed into the 70s
while dewpoints in the 50s have been observed.
As we progress through the remainder of the afternoon and overnight
tonight, upstream weakening showers in Minnesota will continue to
weaken as it presses into Lake Superior/western Upper Michigan. HRRR
and other CAMS suggest it may hold together enough to support some
showers in our forecast area late this afternoon/early evening.
Otherwise, expect temps to continue climbing into the upper 70s to
low 80s and increasing cloud cover.
Impressive instability will continue building on the south side of
the decaying shower activity over Minnesota. As this area of
instability grows and southwesterly low level winds strengthen this
evening, a line of thunderstorms will develop over central
Minnesota. These will grow upscale and evolve into a bowing MCS as
they stream southeast along the instability gradient. CAMS appear to
be coming into better agreement that the strongest storms will stay
south of our forecast area, but storms capable of mostly damaging
winds can`t be ruled out early in the event. Some large hail will
also be possible. The main risk area will be in the counties
bordering Wisconsin. North of this bowing segment, the HRRR and to
some degree, the FV3 and NAMNEST resolve a secondary line of showers
and thunderstorms across the Arrowhead into Ontario, then press
these into Lake Superior and Upper Michigan. Some large hail and
maybe strong winds will be possible with these storms if the
materialize, but confidence in these developing is low to medium (25-
50%) given their proximity to the main bowing segment and the lack
of a consensus among the various CAMS solutions. If this develop,
these and the northern fringes of the MCS pressing southeast, will
press eastward through Upper Michigan, likely clearing the east just
after sunrise. While confidence in the evolution is lacking
somewhat, consistent temporal signatures in the various CAMS suggest
the main period of thunderstorms to be between 5z and 11z with the
most likely period for strong to severe being early in the event.
&&
.LONG TERM /TUESDAY THROUGH MONDAY/...
Issued at 446 PM EDT Mon Jun 24 2024
Starting Tuesday morning, the mid level trough will be situated
over far northwestern Ontario with the associated sfc low just ahead
of it at 988mb near the western shores of James Bay. This low`s cold
front will be draped southeast along the west end of Lake Superior
and into northwest WI. Lingering convection from tonight will likely
be over the far east where the warm front continues shifting east
out of the area. With instability dropping off, confidence in severe
weather is low for the morning as this moves out. Dry weather
returns to all in our CWA by mid morning as the cold front presses
east. Stronger mixing begins behind the cold front resulting in some
gustier west to northwest winds up to 30 mph and drier RHs down into
the 30%, possibly some upper 20s near Iron Mountain. Strongest gusts
are expected in the Keweenaw and northwest, coupled with the lower
RHs. Tuesday is also expected to be the hottest day this week with
highs in the 70s to mid 80s, warmer in the south central UP. That
said, there are no wildfire concerns given the recent wet pattern.
As the cold front makes it`s way through the area, the ARW and HRRR
try to initiate some isolated thunderstorms along the east near Lake
Michigan. The 6/24 12Z HREF mean SBCAPE does build up to 1000 J/kg
in that region, but with model soundings looking moisture deprived.
Left afternoon precip out of the forecast for now.
Tuesday night into Wednesday, the mid level trough continues east
into Quebec and is quickly followed by a shortwave rotating over the
Upper Great Lakes. An additional cold front dropping south will
shift winds out of the north by Wednesday morning and keep winds up
around 5-15 mph through the night, especially over the east and in
the Keweenaw. Lows are expected in the mid 40s to low 50s. Also
given the shortwave, added in some slight chance PoPs late Tuesday
night into Wednesday. Note: There is low confidence at the moment in
location/timing, but nothing impactful is expected. Dry weather and
clearing skies then is forecast for Wednesday afternoon as highs
peak in the 60s. However, those near the eastern Lake Superior
shores may stay in the 50s throughout the day.
With weak high pressure ridging continuing over the region into
Thursday night, dry weather prevails. Radiative cooling Wednesday
night brings lows into the 40s, coolest in the east where the drier
airmass is located. With Highs on Thursday only are expected to warm
up into the low 70s.
Meanwhile, a trough just east of the Pacific northwest will move
onshore Wednesday night. This trough progresses east along the
international border toward the Upper Great Lakes by Saturday
morning with 1 to 2 shortwaves shooting out ahead of it. This will
support cyclogenesis in the northern Rockies Thursday night with the
low ejecting east-northeast to the northern end of Lake Superior for
Friday night/Saturday. Thus, PoPs increase Thursday night into the
weekend. With the low weakening as it moves through and little
instability, hazardous weather seems unlikely at this point. Drier
weather looks to return the rest of the weekend into Monday as high
pressure returns, but confidence is growing in another low pressure
system pushing off the Rockies and moving northeast into the
Upper Great Lakes region for early next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 645 PM EDT Mon Jun 24 2024
VFR conditions will prevail this evening, followed by a rapid
deterioration as a line of thunderstorms moves into Upper Michigan.
Expecting most activity between 5 and 11z, with the greatest
potential for severe winds, maybe some large hail, at KIWD early on
in the event. Expect ceilings to fall to MVFR/IFR after the line
moves through with some brief fog/mist developing before the
sunrise. Tuesday, gusty winds are expected to develop as ceilings
improve. Initial thoughts are KCMX could gust near 30kts from the
west.
&&
.MARINE...
Issued at 446 PM EDT Mon Jun 24 2024
Southeast winds increase this evening to around 20-30 kts, backing
south tonight ahead of the cold front; strongest winds are expected
over the east between the north and eastern Lake Superior buoy`s
where there is a 15% chance for gale force gusts to 35 knots
tonight. Strong to severe storms are possible tonight into Tuesday
morning ahead of the cold front. On Tuesday, gusty westerly winds
are expected behind the cold front to 20-30 kts. Strongest winds are
expected over the central third of the lake between Isle Royale and
the Keweenaw. This will be another period with even higher potential
for some gale force gusts to 35 kts. (Chance of gusts exceeding 34
kts ~40%). This period of longer fetch and stronger winds will help
waves build up to 4-6 feet Tuesday afternoon and evening north of
the Keweenaw. Winds around 20-25 kts veer north Tuesday night behind
an additional cold front that drops south across the lake before
tapering off below 20 kts Wednesday morning. With high pressure over
the lake through Thursday, winds are expected to mainly remain below
20 kts. A weakening low pressure tracking through the Upper Great
Lakes early this weekend will allow for gusts near 20 kt Friday and
Saturday. High pressure returns Sunday and ushers in light winds.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JTP
LONG TERM...Jablonski
AVIATION...07
MARINE...Jablonski
Area Forecast Discussion
National Weather Service Phoenix AZ
503 PM MST Mon Jun 24 2024
.UPDATE...Updated 00Z Aviation Discussion.
&&
.SYNOPSIS...
Daily thunderstorm chances will persist through most of this week
due to enhanced moisture levels lingering across the region. The
greatest chance will be through Wednesday, before decreasing some
late this week and into the upcoming weekend. Conditions will
remain hot and humid, with temperatures remaining several degrees
above normal.
&&
.DISCUSSION...
The early afternoon radar and satellite imagery showing the usual
midday showers and thunderstorms forming over the high country
north and east of Phoenix. The Phoenix valley into southwest AZ
remaining more stable at the moment after early morning clouds
dissipated. The latest SPC analysis showing lingering convective
inhibition in these areas, but experiencing full insolation early
this afternoon. Plenty of moisture ready to be acted on with
Precipitable Waters close to 2 inches across the region.
Our early Monsoon enhanced moisture levels will result in more
shower and thunderstorm into this evening. The latest HRRR hinting
on a bit more widespread northeast outflow driven convection
spreading into the phoenix valley into this evening, even pushing
further southwest toward Yuma County after midnight. This seems
reasonable given more instability and daytime heating across SC
AZ this afternoon with any outflows able to break through any
lingering capping. Although, not a given, as many other high
resolution models not as robust with this solution. Have included
a 20 to 30 percent chance into the forecast. Strong outflow wind
probabilities continue to run low as HREF probabilities of 35+ mph
wind gusts remain around 10-30% across the higher terrain and
lower elevations of southcentral Arizona, so appears mainly a
heavy rainfall threat for storms that develop.
Shower and storm potential does try to trend downward as upper
level ridge retrogrades into AZ/NM region this week, which could
tend to inhibit convection, especially for the lower deserts.
However, given abundant moisture in place, the high country should
still see additional storm formation. By Thursday and Friday,
watching a stronger trough dig across the northern Rockies, which
will break down the ridge over AZ, but also shunt deeper moisture
to the south. This should further inhibit storm potential and
confine it to mainly far SE and Eastern AZ into first half of the
weekend.
After this trough passes to the northeast, ridge builds again
across the SE U.S. which will bring back the southerly flow and
moisture that is poised to move back north into the region as
early as Sunday. This will increase storm chances again into next
week. CPC outlooks for 8-14 days (the first week of July) favors higher
percentages for above normal precipitation.
With all the moisture and associated clouds and precipitation,
daytime high temperatures overall staying several degrees above
normal through the period, but at least not near record levels.
However, overnight lows will remain well above normal. This will
all spell a consistent moderate HeatRisk across the region through
the period for hot and humid conditions persisting. However, not
to the levels of excessive heat at this time.
&&
.AVIATION...Updated at 0000Z.
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Westerly wind gusts of around 20 kt will continue into the early
evening. There are two outflow boundaries out there currently that
are moving into the Metro, one from the NW and one from the NE.
The NE one might win out, mainly for KPHX and KIWA. But the winds
could do some flip-flopping with the arrival of these outflows. We
will also have to watch for any initiation of showers or storms
as these outflows collide. Winds are expected to go light and
variable late this evening and through the morning hours before a
westerly component is developed. FEW-SCT mid and high level
clouds will continue through the TAF period, and may occasionally
become BKN.
Southeast California/Southwest Arizona including KIPL and KBLH:
Winds will follow their typical diurnal trends at both terminals,
with occasional afternoon and evening gusts near 20 kts. FEW-SCT
high clouds will continue to filter in through the TAF period.
&&
.FIRE WEATHER...
Monsoonal moisture will continue to result in daily chances for
shower and thunderstorm activity, especially into midweek. The
higher terrain areas will see the greatest potential with some
locally heavy rainfall with any storms that develop. Chances for
wetting rains will generally remain around 10-20% for the higher
terrain areas and 5-10% for the lower deserts of south-central
Arizona through the first half of the week. Shower and
thunderstorm chances will gradually diminish throughout the week,
as high pressure builds into the region. With the elevated
moisture in place, MinRH values through early this week will range
between 30-40% across the far eastern districts to between 15-25%
across the western districts before slowly drying into the middle
to latter half of next week. Winds will follow their typical
daily tendencies, with gusty outflows from any thunderstorm
activity anticipated over the next several days. Temperatures
average several degrees above normal through the forecast period.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
DISCUSSION...Frieders
AVIATION...Berislavich
FIRE WEATHER...Frieders
Area Forecast Discussion
National Weather Service Raleigh NC
958 PM EDT Mon Jun 24 2024
.SYNOPSIS...
Weak high pressure will pass over the area late tonight through
early Tuesday, then push quickly offshore late Tuesday, allowing hot
and humid conditions to return for Wednesday. Another front will
approach from the northwest early Thursday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 955 PM Monday...
The 00Z upper air analyses show the H25 trough over the Northeast
and mid-Atlantic, while the H5 trough was slightly east, mainly
along the East Coast. There is still plenty of moisture evident at
H7 and H85, although some drier air was creeping into the northern
Piedmont. At the surface, the front has progressed through most of
central NC, however there are still some mid 70s dewpoints over the
Coastal Plain as of 01Z. Dewpoints elsewhere generally range from
mid 60s to mid 60s. The surface high, over OH/PA as of 01Z, should
settle ssewd to over WV/VA tonight. The question is if the surface
boundary will remain stalled over the Coastal Plain tonight or
whether/how far the high will help push it sewd. Where the higher
dewpoint air remains, some fog/low stratus will be possible.
Otherwise, expect lows mainly in the mid 60s to around 70 degrees,
although a few isolated spots could stay a bit above 70.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
As of 400 PM Monday...
Tuesday will be largely precipitation free across central NC as the
trough exits into the Atlantic and is replaced by weak ridging over
the Southeast US. Our region will also be under a much drier more
stable airmass behind the cold front. Surface high pressure over the
Appalachians in the morning will move east into the Atlantic during
the day, shifting the low-level flow to a more southerly direction.
Thus there will be very little to no change in temperatures from
today despite today`s cold frontal passage, with highs again in the
lower-to-mid-90s. Where there will be a noticeable difference is the
humidity, as dew points will mix out into the upper-50s to lower-60s
in the afternoon. So heat indices will be very similar to the air
temperatures. The one possible area of precipitation is from
Fayetteville south and east, where some CAMS (mainly the HRRR and
RAP), show enough instability for a few showers and storms to
develop along the sea breeze. But the other CAMS are much less
impressed. Given this and the unfavorable upper pattern, only carry
slight chance POPs there at this time. Lows Tuesday night will be in
the upper-60s to lower-70s.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY...
As of 205 PM Monday...
...Hot Temperatures Will Continue through Next Weekend...
...Seasonable/Climo Rain Chances Return...
Heat and humidity increases Wednesday ahead of another approaching
weak cold front that will cross the area Wednesday night/early
Thursday. Wednesday looks to be the hottest day of the week, with
afternoon temps expected to top out between 95-100, and heat indices
in the upper 90s NW to 100-105 over central and eastern NC. While
some isolated pre-frontal convection is possible Wednesday
afternoon/evening, the bulk of central NC will most likely see it`s
rainfall from an ana-frontal rain band that will cross the area late
Wednesday night and Thursday. There`s a very plausible chance that
the front could stall out or quickly lift back north as a warm front
on Friday, resulting in additional rain chances. Right now,
precipitation amounts looks to be light, with average rainfall
amounts expected to be between 0.10-0.25", with some localized
heavier amounts.
The heat should briefly moderate on Thursday with troughing moving
through. However, the subtropical ridge initially centered over the
southern Plains will expand eastward into the Southeast Friday and
over next weekend, bringing a renewed threat for hazardous heat with
heat indices again in the upper 90s NW to 100 to 105 across central
and eastern NC.
Another cold front, potentially the strongest of the week, is slated
to cross the area late Sunday into the day on Monday, and will bring
additional rain chances in showers and storms, and another brief
stint of cooler, less humid conditions early next week.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
As of 650 PM Monday...
There will generally be VFR conditions through the 24-hour TAF
period. The only threat of some sub-VFR conditions would be at FAY
and RWI. The cold front has pushed through, although some of the
recent CAMs indicate there could be an isolated shower at FAY or RWI
between 00-03z. Confidence on this occurring is too low to mention
in the TAF. Moisture will be slow to erode at FAY/RWI overnight
tonight and because of that, some low stratus or fog could form at
these terminals into early Tue. Confidence is overall low but was
high enough to mention in a TEMPO group with low 70s dewpoints over
the Coastal Plain. VFR should prevail at all sites Tue morning and
afternoon, though a low-end chance of a shower or storm could form
at FAY in the aftn/eve with the sea-breeze.
Looking beyond 00z Wed: Some early morning stratus or fog could form
Wed morning. Isolated late day storms are possible late Wed,
followed by a better chance of afternoon/evening showers and storms
Thu, along with possible sub-VFR ceilings Thu morning. Otherwise,
outside of any storms, the risk of widespread sub-VFR conditions is
low through Sat.
&&
.CLIMATE...
Record High Temperatures:
June 24:
KRDU: 99/2010
KFAY: 102/1914
June 25:
KRDU: 100/1952
KFAY: 102/1914
June 26:
KRDU: 102/1952
KFAY: 101/1951
June 27:
KFAY: 102/1998
Record High Minimum Temperatures:
June 24:
KGSO: 76/2015
KRDU: 76/1888
KFAY: 79/2010
June 25:
KFAY: 75/1952
June 26:
KGSO: 74/2010
KRDU: 76/1902
KFAY: 76/1997
June 27:
KGSO: 76/1969
KRDU: 76/1952
KFAY: 77/1998
June 28:
KGSO: 76/1969
KRDU: 76/1952
KFAY: 78/1914
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Hartfield
NEAR TERM...KC
SHORT TERM...Danco
LONG TERM...CBL
AVIATION...Kren/Hartfield
CLIMATE...RAH