Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/29/24
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
113 PM AKDT Fri Jun 28 2024
.SYNOPSIS...
Warm weather will continue over much of the Interior through the
weekend. Areas of dense smoke from fires burning is reducing
visibilities over the Middle Tanana Valley. Smoke will be in and
out through the weekend. Scattered thunderstorms are expected
north and east of Fairbanks. Isolated storms will persist into
the weekend.
&&
.DISCUSSION...
Analysis and Model Discussion...
A strong ridge of high pressure aloft remains over the eastern
half of Alaska, & the center has shifted northward to be over the
eastern North Slope. The ridge has weakened slightly today with
temperatures remaining warm to downright hot in some areas. A
strong vertically stacked low will remain in the central Bering Sea.
A number of shortwaves are moving northward between the low and
the ridge this afternoon bringing scattered thunderstorms from the
western North Slope SE to Fort Yukon this afternoon and evening.
Convection on Saturday looks to just be isolated over the eastern
Interior but widely scattered right along the Alcan Border and in
the SE Brooks Range. Models in good agreement through the short
term. The HRRR smoke model showing smoke persisting over the
Interior.
Interior...Warm weather will continue over much of the Interior
through the weekend. Highs in the mid 80s and a few upper 80s over
the Yukon Flats. Areas of dense smoke from fires burning is
reducing visibilities over the Middle Tanana Valley. Smoke will be
in and out through the weekend. Dense smoke advisories have been
extended into Saturday. Smoke may thin and visibility may improve
in the afternoon around Fairbanks but become dense again early
morning on Saturday. High pressure builds back in for the weekend
with rising temps back into the 80s, and much lower thunderstorm
activity, with that ridge aloft suppressing thunderstorm
potential. Isolated thunderstorm threat returns over the southern
Interior on Sunday.
West Coast and Western Interior...
Showers will continue to rotate around the large Bering low along
the West Coast. Isolated overnight thunderstorms will continue
into this morning today over the W Interior to NW Arctic, with
more afternoon thunderstorms mainly over the Upper Kobuk Valley
north to the Brooks Range, with just some isolated spotty thunder
farther south toward the Alaska Range to the Kuskokwim Mtns.
North Slope and Brooks Range...
Another warm day today with more very active thunderstorm
activity, as a thermal low will remain parked over the Brooks
Range. Scattered to numerous thunderstorms will be possible from
the W Brooks Range east to Chandalar, with some storms being very
strong and capable of producing very heavy downpours, frequent
cloud to ground lightning, and hail up to half an inch. Northwest
winds will cool temps back down closer to normal values albeit
still warmer than average. On Saturday, the thunderstorm threat
moves Anatuvak Pass to the AlCan border. For now, widely scattered
wet thunderstorms are expected. On Sunday, isolated storms return
over the southern Interior.
Extended Forecast Days 4-7...
By Monday, a narrow Mainland ridge aloft will still be in place,
but there will be a series of lows which will move overtop that
ridge, gradually weakening it and bringing wetter onshore flow to
the NW Arctic and down the West Coast Tuesday and Wednesday, with
those fronts moving inland by the latter half of the week. This
should allow for some relief from hot temps and may even bring
rain into the Interior.
Coastal Hazard Potential Days 3 and 4...None.
&&
.FIRE WEATHER...
Red Flag Warnings are in effect for lightning for the Yukon Flats
and SE Brooks Range where we expect scattered wet thunderstorms,
though an isolated dry storm is possible. Temperatures will cool
only slightly and RHs will moderate. On Saturday, the
thunderstorm threat moves Anatuvak Pass to the AlCan border. For
now, widely scattered wet thunderstorms are expected. On Sunday,
isolated storms return over the southern Interior.
&&
.HYDROLOGY...
Heavy rain showers and thunderstorms over the Brooks Range today
may feed into faster moving streams and cause rapid rises, which
will remain high into this weekend. Glacial fed rivers including
the Tanana are beginning to rise as warming temperatures lead to
increased high elevation snowmelt.
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Red Flag Warning for AKZ911-933.
PK...Small Craft Advisory for PKZ801-802-850.
&&
$$
JK
AREA FORECAST DISCUSSION
National Weather Service Albany NY
944 PM EDT Fri Jun 28 2024
.SYNOPSIS...
High pressure will depart off the coast of New England tonight,
allowing for increasing clouds, with temperatures not as cool
as last night. It will be mostly cloudy, breezy and more humid
on Saturday with an increasing chance for showers and
thunderstorms through the day. Showers and thunderstorms, some
with heavy downpours, is expected on Saturday night for much of
the area. A lingering shower or thunderstorm is expected on
Sunday with warmer temperatures, before drier weather returns
for the start of the upcoming week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
.UPDATE...Main change with this update was to expand likely PoPs
eastward to include the Capital District around or shortly after
sunrise, due to a surge of moisture along with warm advection.
The past few runs of the HRRR have consistently shown a batch
of showers moving E-NE from central overnight. Most of the
showers should be light into early Sat morning, although a few
embedded brief heavier showers may occur in some spots.
.PREV DISCUSSION[0751]...Tranquil/dry conditions in place
across the region early this evening. Dewpoints remain low in
the 40s to mid 50s range, resulting in lower than usual humidity
for late June. Satellite imagery shows high/mid level clouds
increasing from the west. Made some minor adjustments based on
latest obs, with no significant changes with this update.
As high pressure starts to depart off to the east this evening,
some mid and high level clouds (currently seen over western New
York) will spread towards the area for this evening into
tonight. In addition, a southerly flow will start to increase
across the region for the overnight hours. With the increasing
clouds and the breeze, temps won`t be as cool as last night,
with lows in the 50s.
A warm front over the Ohio Valley and mid Atlantic will start
moving northeast for late tonight. With increasing moisture
within the southwest flow aloft, an area of light rain will be
developing across western and central New York overnight. This
may spread towards the Adirondacks and Mohawk Valley for late in
the overnight and towards daybreak on Saturday. Amounts through
sunrise on Saturday look fairly light and limited to
northwestern parts of the area.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
On Saturday, the warm front will continue lifting northeast
towards the area. Our region will be in broad south to southwest
flow aloft ahead of an approaching upper level disturbance over
the Great Lakes. The low level jet will be around 50 kts,
allowing for plenty of moisture advection and warm air
advection from the southwest. Our area will remain on the
northern side of the surface boundary through much of the day on
Saturday, so surface-based instability looks fairly limited.
Based on the 12z SPC HREF, our area may finally start to see
some minor amounts on instability by Sat night (mainly under
1000 J/kg) and it`s unclear still if this will be surface-based
or not, as the timing within the diurnal cycle may allow for
this to elevated. 0-6 km bulk shear will be increasing thanks to
the strong flow aloft, with values in the 40 kt range. Plenty
of moisture will be increasing across the region with PWATs
rapidly rising to around 2.00 inches by Sat evening. However,
the moist profile will keep lapse rates rather poor across the
region.
Some light rain or showers will be ongoing for far northern
areas early on Sat morning. However, as these continue to track
eastward towards New England, they will be weakening and
dissipating as they run into a drier air mass. However, the
approaching warm front will allow for another batch of showers
to spread towards the area from the west for Wed afternoon or
early evening. Most of this activity is expected to impact
western and northern areas. There may some embedded heavier
bursts, but the bulk of this looks fairly light. Otherwise,
skies will be mostly cloudy through Saturday with temps only in
the 70s.
As our area gets into the warm sector and we finally get some
instability in place, there will be the potential for some
heavier downpours on Sat night, as the pre-frontal trough allows
for additional areas of convection to develop. CAMs had
different ideas on the exact placement and coverage of this
precip, so this is somewhat uncertain. However, there could be
some heavier downpours on Sat night for parts of the region, and
ponding in urban/poor drainage areas will be possible,
especially if repeated rounds occur. Can`t rule out a rogue
strong wind gust due to the decent shear and high moisture in
place, but limited instability will keep this threat fairly
isolated. Temps will remain mild and muggy in the mid 60s to low
70s with much stickier dewpoints than recent nights.
On Sunday, the surface cold front will be passing through the
region from west to east. It may cross western areas earlier in
the day, but will cross southeastern areas in the afternoon.
Enough heating should occur ahead of the front to allow temps to
reach into the 80s, especially southeastern areas. While the
morning should be fairly quiet, some convection may develop
ahead of the boundary for the afternoon hours. Exact coverage is
still in question, but enough instability and shear could be in
place for some stronger storms before activity heads towards the
coast for late in the day. SPC has a marginal to slight risk
across the region, although the greatest threat may be just
southeast of the area, although it will depend on the exact
timing of the front. Behind the boundary, cooler and less humid
air will return to the region for Sunday night with clearing
skies.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
Mainly quiet weather is expected through the long term period.
High pressure will be passing over the area for Monday into
Tuesday. This will allow for dry conditions with fairly clear
skies. Dewpoints will remain comfortable in the 50s. After highs
in the 70s on Monday, they will rise into the 80s on Tuesday.
Mon night will likely be another clear and cool night with lows
in the 40s and 50s once again.
By the middle of the week, temps and humidity levels will be
rising as our area gets back into the return flow on the
backside of the departing high pressure area. Highs will be well
into the 80s for Wed through Fri, with dewpoints into the 60s.
At this point, heat index values look just below advisory
criteria, but will need to watch closely in case temps/dewpoints
look higher. It should continue to be dry most of the time,
although some spotty showers (or perhaps an isolated t-storm)
will be possible during the late week, mainly in the diurnally
favored afternoon or evening hours. At this point, forcing and
dynamics look weak, so the potential for strong storms looks low
at this time.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
Through 00z Sunday...VFR conditions are expected to prevail
through the night with increasing high then mid level clouds
ahead of an approaching warm front. The warm front will bring
showers Saturday morning from the KGFL-KALB corridor starting
around 09z-11z. These showers will likely stay north of KPOU,
but could get near KPSF so will mention VCSH there. Cigs will
gradually lower to MVFR levels Saturday morning due to
increasing moisture, but could remain VFR at KPOU for several
more hours.
Periods of showers will likely continue Saturday afternoon from
KGFL-KALB as the warm front pushes north/east. There will be a
better chance of showers developing at KPSF by Saturday evening,
while the majority should still remain north of KPOU. Conditions
are likely to be MVFR at all sites prior to 00z Sunday.
Winds will be variable around 5 kt or less through the evening,
becoming south-southeast around 5-10 after 06z Saturday. Winds
on Saturday will be southerly and steadily increase to around
10-15 kt with gusts of 20-25 kt.
Outlook...
Saturday Night: High Operational Impact. Breezy. Definite SHRA...TSRA.
Sunday: Moderate Operational Impact. Breezy. Chance of SHRA...TSRA.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: No Operational Impact. NO SIG WX.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...Frugis
NEAR TERM...Frugis/JPV
SHORT TERM...Frugis
LONG TERM...Frugis
AVIATION...JPV
Area Forecast Discussion
National Weather Service La Crosse WI
649 PM CDT Fri Jun 28 2024
.KEY MESSAGES...
- A few more showers/storms tonight. A conditional severe risk this
evening, moreso for northeast IA.
- Aside from spotty light showers, mostly north Sat afternoon, dry
and cool conditions expected Sat into Mon.
- More showers and storms Monday night into Tuesday. Heavy rain
threat. Conditional severe threat Tuesday into Tuesday evening.
&&
.DISCUSSION...
Issued at 245 PM CDT Fri Jun 28 2024
* REST OF THE AFTERNOON/TONIGHT: storm chances - conditional severe
threat for northeast IA into the evening
Extensive cloud cover has persisted into the early afternoon while
the morning rains have moved east/south of the local forecast area.
The clouds are inhibiting daytime heating, thusly working against
sfc destabilization. A thin line of showers/storms has developed in
southern MN/IA on the western flanks of the cloud, on the edge of
the MLCAPE plume (100-250 J/kg), a small region of differential
heating plus what looks like a remnant MCV (per watervapor imagery).
These should continue to push east, but will quickly run out of
instability a loft.
CAMS models continue to provide a wealth of potential outcomes,
almost by the hour, lowering confidence in how the evening will
unfold. A few things to focus on though. The MCV should continue to
provide enough lift for shower/storm production into the evening as
it shifts across the area. Again, instability is limited. With
RAP/HRRR soundings holding the cap in place (thanks clouds),
effective wind shear will be mostly above 1 KM...with fairly short
hodographs. Not sure there is much there to support whatever CAPE
can be realized.
To the west a cold front is advancing east and right around the
boundary RAP/HRRR soundings show some uptick in instability
profiles, although still suggesting the CAP could hold (non sfc
based). Showers/storms should develop along the front, but likely
more favored along the southern flank - in Iowa. These would have a
bit more promise for strong/severe upscaling with a deeper
instability pool, moisture axis to work with.
In additional to all this is the potential interplay of the low
level jet. Currently the RAP has a fairly steady stream of 850 mb
moisture transport from IA into central WI, with a gradual shift
eastward ahead of the front through the evening. Not much
convergence. However, the HRRR refocuses the jet into southwest WI
by 00-02z, resulting in blossoming of convection. Instability still
limited at best and doesn`t have a lot of strong-severe support.
Overall, a few more showers and storms this evening. A conditional
severe risk continues, but more focused into IA and associated with
the cold front. Certainly a scenario to monitor.
* SAT NIGHT/MON: cooler, drier
Aside from a shortwave trough/cold air advectively driven afternoon
shower chances, mostly north of I-94 Sat, the local area is looking
at a few dry days for a change. High pressure at the sfc slides
across the region Sunday while a shortwave upper level ridge edges
over the upper mississippi river Mon morning. EPS/GEFS paint highs
for most of the area in the lower 70s - a consistent signal with
only a few degree spread in the 25/75 percentiles. Meanwhile, the
LREF suggests little chance (0 to 10%) to warm into the upper 70s
Sun/Mon. So, expect cooler, but perhaps welcomed conditions to kick
off the new week.
* MON NIGHT/TUE: more rain, storm chances - heavy rain threat
Long range guidance remains in good agreement with driving ripples
of upper level energy eastward from the PAC NW, with the progressive
zonalish flow tracking them over the upper mississippi river valley
Mon night/Tue. Broad low level thermodynamics will precede the upper
level forcing while an attendant north-south running sfc cold front
currently set to track across the region Tue afternoon/eve.
Potential 300 mb jet streak Tue could enhance lift along the front
via its right entrance region.
Broad area of rain should break out/shift in from the west late
Monday afternoon, night in response to the thermodynamics. Not much
for instability at this time but couldn`t rule out at least a few
storms thanks to the nose of a 50 kt 850 mb jet. Favoring mostly
rain though.
Moving into Tue, more bits of shortwave energy/MCV will come into
play along with the cold front. Questions on how much cloud
cover/rain early in the day will be lingering with impacts on
atmospheric recovery/destabilization. SBCAPE in the LREF currently
progged from 1-1.5+ J/kg in the afternoon with favorable deep layer
shear to support strong/severe storm development. VERY conditional
with a lot of unknowns - that may not become more clear until the
actual day.
While the severe threat is murky at this time, the potential for
heavy rain is a bit more clear. PWs in the LREF pushing near 2+"
while ECMWF and NAEFS PW anomalies creep up to 2.5. EFIs even edging
above 0.70. Add in the persistent low level jet and moisture
transport with warm cloud depths from 4 to 4.5 kft and the setup is
very favorable for heavy rain. Obviously how the system unfolds,
where the variety of forcers set up/move, and potential training are
all important factors that are much less clear. Still, as it sits,
the setup is there and will have to be watched closely - especially
given the ongoing flooding and/or high running river systems. More
water is not needed.
* THU/FRI RAIN CHANCES
The GEFS and EPS continue to trend toward rain chances for the end
of the new work as the both shift an upper level shortwave from the
PAC NW eastward across the region. However, not all their members
agree on timing/placement for the resulting QPF - a few even suggest
it could be dry, shifting the pcpn away from the area. Less
agreement compared to some previous model runs. Given the currently
progged upper level dynamics, still looks like a good shot for rain,
albeit with potential to shift in location/timing. On the plus side.
the heavy rain parameters via the GFS are shifting more south and
east of the local area. A trend the area would welcome given the
recent heavy rain and expectations as we move into the early part of
the new week.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 648 PM CDT Fri Jun 28 2024
A mesoscale convective complex will move east of the forecast
area by 29.03z. The showers and storms associated with this
system will move east of KLSE within the next hour. Another line
of showers and storms is being watched to our northeast, but
current thinking is that line will stay north of the TAF sites.
While the precipitation will be moving out of the area, ceilings
will likely remain IFR and MVFR through the evening.
With clearing skies and winds less than 10 knots during the
late evening and early overnight, we will have to look out for
the potential of fog development. For the time being, went with
BCFG at KRST and 1 1/2sm br at KLSE between 29.09z and 29.13z.
Skies will clear briefly on Saturday morning and then a 2500 to
500 deck of clouds will move into the area during the evening.
&&
.HYDROLOGY...
Issued at 425 AM CDT Fri Jun 28 2024
With three more periods of precipitation ahead - today into
tonight, Monday/Tuesday, and Thursday/Friday - area rivers will
remain swollen. Both of those first two rounds in particular
show the potential for many areas to pick up around another
1-2". Given this and the large amount of water flowing
downstream, the Mississippi River is expected remain in minor to
moderate flood through at least the next five days.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...Ferguson
AVIATION...Boyne/EMS
HYDROLOGY...Ferguson
Area Forecast Discussion
National Weather Service Cleveland OH
1017 PM EDT Fri Jun 28 2024
.SYNOPSIS...
Low pressure will track from the northern Plains into the
northern Great Lakes tonight, lifting a warm front through the
region by Saturday morning. A trailing cold front will sweep
across the region Saturday night into Sunday morning as the low
tracks into Quebec. High pressure will build into the region
Sunday and Monday before moving east Tuesday.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
10:15 PM Update...
The bulk of the forecast remains on track but did tweak PoPs and
QPF to account for latest hi-res guidance. Given better
confidence on axis of highest QPF with heavy rainfall expected
early Saturday morning through Saturday evening, opted to issue
a Flood Watch from Lorain County south to Holmes County and
points east. Total rainfall amounts will generally range between
1 and 2 inches with locally higher amounts of 3 inches or more
possible.
Previous discussion...
Very active weather is still expected late tonight and Saturday with
areas of heavy rainfall as well as a few severe storms likely. The
heavy rain and flooding threat is still higher confidence than the
severe weather threat, but there is uncertainty regarding where the
heaviest, most persistent thunderstorms may set up. See details
below.
Water vapor loops this afternoon show a strong mid/upper shortwave
trough and associated closed low moving from the northern Rockies
into the northern Plains. This shortwave will progress into the
northern Great Lakes late tonight and Saturday morning before
becoming absorbed into a broader mid/upper trough digging down
across the Great Lakes by Sunday. The associated surface low,
currently over northern Minnesota, will cross the UP of Michigan
tonight before exiting into Quebec Saturday night, dragging a strong
cold front through the region Saturday night into Sunday morning.
Upstream radar and surface observations show a sign of what`s to
come late tonight and Saturday, with strong warm/moist advection
bringing dew points into the 70s in the warm sector across a large
area of the corn belt, as well as widespread showers and elevated
thunderstorms driven by isentropic ascent ahead of the warm front.
This warm front will slowly lift east-northeastward across the
region tonight into Saturday morning, with strong warm/moist theta e
advection tapping into the aforementioned rich low-level moisture to
the west and southwest. Expect dew points to rise quickly this
evening and tonight, with most dew points touching 70F by 12Z
Saturday. There is no doubt that the environment will become juicy
in a hurry, but the location of the heaviest, most widespread axis
of convection is uncertain.
Regarding heavy rain/flooding details, A 40-50 knot west-
southwesterly low-level jet will feed high theta e air and elevated
instability into the region, with associated isentropic ascent
driving elevated convection ahead of the slowly lifting boundary,
but CAMS are struggling to pinpoint where the best axis will set up.
There is a wide range of possibilities from over Lake Erie to over
the southern and eastern tier of counties, so held off on a Flood
Watch for now given the uncertainty. What is certain is that any
thunderstorms late tonight and Saturday morning will contain highly
efficient (torrential) rainfall rates given PWATs rising to 2 to 2.3
inches (maximum daily value of climatology), very deep, saturated
warm cloud depths, and low LCL heights of 400-800 m to minimize
evaporation. CAMS suggest some training or repeated rounds of
convection is possible before the warm frontal boundary lifts NE,
and with the aforementioned environment supporting rainfall rates in
excess of 3 inches per hour, flash flooding is likely in areas that
see training or multiple rounds despite current 3 and 6 hour FFG`s
being high. Will wait to see where the axis starts to set up tonight
to determine where the greatest flooding threat will be, but heavy
rainfall rates are possible anywhere.
Regarding the severe weather potential Saturday afternoon and
evening, this is far more conditional and uncertain. As the warm
frontal boundary lifts ENE across the region Saturday morning, it is
likely to slow over NE Ohio and NW PA. NAM and RAP forecast
soundings and plan views suggest impressive veering with height near
the boundary leading to curved hodographs and 300-400 m2/s2 of low-
level (0-1Km) SRH. This along with low-level shear of 30+ knots and
deep layer effective shear of 40-50 knots in the morning near the
warm front could support an isolated tornado or two, aided by the
low LCL heights as well. However, instability and time of day are
the biggest limiting factors. Forecast soundings suggest elevated
CAPE over 1000 J/Kg but very little SBCAPE available, so it`s
possible that we just see some elevated rotation along with heavy
rainfall. If severe weather occurs, there is a better chance for the
afternoon and evening as the area gets fully into the warm sector
behind the warm front. Latest CAMS are suggesting a lull most of the
afternoon which could allow for breaks in the overcast and greater
heating/instability. If this occurs, then scattered severe
thunderstorms will redevelop ahead of the cold front and move across
the region from NW to SE during the afternoon and evening. These
storms could produce damaging winds, an isolated tornado or two, and
additional heavy rainfall given deep layer shear staying marginally
favorable (30-35 knots) along with marginally favorable low-level
shear of 20+ knots and low-level SRH of 100-200 m2/s2. However,
there is uncertainty in how much redevelopment will occur since
there could be extensive cloud cover and outflow lingering from the
morning convection. Some CAMS show very little redevelopment or
redevelop the convection SE of the area. At this time, the SWODY2
slight risk still looks reasonable given the shear that could
potentially take advantage of greater heating, but again, very
conditional.
Any showers and thunderstorms will quickly end from NW to SE
Saturday night as the cold front passes through the region and drier
air works in behind it thanks to broad surface high pressure over
the Upper Midwest.
Highs Saturday will range from the low/mid 80s in most areas, but
more precip could keep NW PA and NE Ohio in the upper 70s to around
80. It will be oppressively humid with dew points in the low to mid
70s. The cooler air will start to come in Saturday night with lows
in the low to mid 60s.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
An upper level trough will be over the Great Lakes region extending
into southern Ontario and Quebec during the later part of the
weekend. High pressure at the surface will be centered over the
Upper Midwest on Sunday slowly building into the region. Cooler air
will advect in with a northwesterly flow Sunday. There will be mix
of sun and clouds across the area with more cloud cover down
downwind of Lake Erie. There also could be a few isolated lake
effect rain showers early Sunday morning before the atmosphere dries
out. Afternoon temperatures will reach the lower and middle 70s on
Sunday.
High pressure will continue to build over the region Sunday night
into Monday. Skies will clear out Sunday evening and overnight low
temperatures will fall into the lower 50 middle 50s away from the
immediate lakeshore. Monday will be very nice day with plenty of
sunshine and light winds with the center of high pressure nearby.
Afternoon temps will be in the lower to middle 70s Monday.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
A summertime ridge of high pressure will develop across the Lower
Ohio Valley and Mid-Mississippi River Valley regions by the middle
of next week. Our area will be on the edge of this ridge. Southerly
flow will return on Tuesday with a return to summer like
temperatures climbing into the middle and upper 80s. The humidity
will also start returning Tuesday into Wednesday. A shortwave trough
will move through the Upper Great Lakes region on Wednesday with a
trailing cold front. Wednesday will likely be the hottest day of
next week with temperatures reaching the upper 80s and lower 90s. A
weak cold front will move into the area next Wednesday night with
scattered showers and thunderstorms. This frontal boundary may stall
out from west to east over Ohio Thursday into Friday with multiple
rounds of showers and storms possible towards the end of next week.
High temperatures will remain in the middle to upper 80s late next
week.
&&
.AVIATION /00Z Saturday THROUGH Wednesday/...
VFR conditions will continue across terminals through the rest
of this evening and early tonight. Rain showers will begin to
approach western terminals early Saturday morning (roughly
06-09Z) and gradually move eastward through the morning and
afternoon. Instability will increase by late morning which will
allow for instances of isolated to scattered thunderstorms
embedded in rain. As heavier rain and thunderstorms move
overhead, expect for MVFR cigs/vis with IFR possible in heaviest
showers and storms. Kept rain mentions in eastern TAFs through
the afternoon to account for the potential for showers to
redevelop along and east of I-71. Conditions will gradually
improve back to VFR near the end of the TAF window.
Generally southerly winds 8-12 knots tonight and early Saturday
will turn southwesterly while increasing to 12-15 knots with
gusts up to 20-25 knots. By the end of the TAF window, winds
become westerly while diminishing below 12 knots.
Outlook...Non-VFR possible in showers and thunderstorms
Saturday afternoon into Saturday night. Non-VFR possible in
showers and thunderstorms Tuesday night and Wednesday.
&&
.MARINE...
Southerly, offshore flow will continue at 10 to 15 knots tonight.
The flow will become southwesterly on Saturday and increase 15 to 20
knots ahead of an approaching cold front. The front will move across
Lake Erie Saturday evening. Winds will shift from the northwest and
onshore around 15 knots Saturday night through Sunday afternoon. We
could briefly reach SCA conditions for a few hours Saturday night
into Sunday behind the front but confidence is uncertain at this
time. Waves will be higher along the lakeshore by Saturday evening
and overnight. High pressure will build in Sunday night into Monday.
Winds will be northerly Sunday night 10 to 15 knots. On Monday,
winds will shift from the northwest around 10 knots becoming light
and variable by Monday evening. South to southeasterly winds around
10 knots will return on Tuesday and further increase 15 to 20 knots
from the southwest by next Wednesday.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...Flood Watch from 4 AM EDT Saturday through Saturday evening
for OHZ010>014-020>023-031>033-038-089.
PA...Flood Watch from 4 AM EDT Saturday through Saturday evening
for PAZ001>003.
NY...None.
MARINE...None.
&&
$$
SYNOPSIS...Garuckas
NEAR TERM...Garuckas/Iverson
SHORT TERM...Griffin
LONG TERM...Griffin
AVIATION...Iverson
MARINE...Griffin
Area Forecast Discussion
National Weather Service Cheyenne WY
541 PM MDT Fri Jun 28 2024
.KEY MESSAGES...
- Active weather pattern ahead, with a cooling trend possible
next week due to several passing cold fronts.
&&
.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 159 PM MDT Fri Jun 28 2024
Radar continues to be quiet, only showing a few lonely blobs across
the southern Nebraska panhandle. Hi-Res guidance continues to trend
precipitation downwards, however, severe weather still cannot be
ruled out with the RAP showing a bubble of 2000 J/kg of CAPE later
this afternoon in Kimball and Cheyenne Counties. Being in the
right entrance region of a 250 mb jet streak and and forcing
from an incoming secondary cold front should provide the
necessary lift, however, the better environment looks south of
the Nebraska/Colorado border. If storms do develop, they should
dissipate by this evening.
Quiet weather is expected on Saturday as brief ridging passes over
the Rockies. For the most part, this should keep storms at bay,
however, a weak disturbance aloft could spark some convection
along the high terrain. Temperatures behind the cold front will
be about 10 degrees cooler compared to Friday, so mainly looking
at highs in the mid 70s to low 80s.
More severe weather is possible on Sunday as the ridge slides
eastwards and a trough begins to enter western CONUS. Southwest flow
aloft will usher in a plume of moisture east of the Laramie Range.
Combined with more southerly surface flow into the panhandle, PWs
will be over an inch, which is roughly the 90th percentile for this
time of year. This will likely lead to heavy rain in storms Sunday
afternoon. As mentioned, severe weather could be possible with a
weak shortwave passing overhead. Currently, it appears more like a
wind threat on Sunday with DCAPE values exceeding 1200 J/kg. Can`t
rule out some large hail with MUCAPE values approaching 1500 J/kg.
Hi-Res guidance shows wide scattered storms throughout the day, so
we`ll have to monitor most of the CWA.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 315 PM MDT Fri Jun 28 2024
Medium range models in good agreement with the overall weather
pattern through Wednesday, but then models diverge significantly
late this week...including Independence Day. Starting on Monday,
models indicate another Pacific upper level trough and
associated cold front pushing southeast across Wyoming and
western Nebraska late in the day after the brief warm up on
Sunday. Another round of windy conditions are possible,
especially west of I-25, as the cold front slides east across
the area. Not expecting High Wind criteria (40+ mph
sustained/58+ mph gusts) at this time, but a few recent events
have overperformed, so will have to keep an eye on this one for
mainly Monday morning through mid Monday afternoon. Thunderstorm
probabilities actually look lower on Monday due to dry westerly
winds and substantial mid to high cloud cover shown by most
deterministic models and also the majority of ensembles as the
cold front moves into the area. Kept POP between 15 to 25
percent for most areas with higher coverage/chances in the
mountains and east central Wyoming/northern Nebraska Panhandle.
Slightly cooler weather is expected for Tuesday and Wednesday as
most models show northwest flow aloft and east to southeast
winds at the surface. However, afternoon temperatures should
still be seasonable for this time of the year with highs in
upper 70s to middle 80s. Models and ensemble are hinting at a
lower coverage of showers and thunderstorms across the area,
even with the natural convergence zone along the Laramie Range.
Further analysis indicates relatively low PWAT for this time of
the year across southeast Wyoming with values around 0.40 to
0.60 inches. Granted, this is enough for thunderstorm initiation
but strong to severe storms look unlikely at this time and
limited to gusty outflow winds. Lower PWATs are likely due to
the progressive west to northwest flow across the Pac NW and
northern/central plains, with poor moisture transport from the
Gulf of Mexico. Will continue to keep an eye on this since
northwest flow in July can lead to some pretty big severe
weather events, but without the moisture, kept POP below 25
percent for now.
For later in the week, large ensemble spreads exist for both
precipitation and especially temperatures. Deterministic models
show a pretty strong upper level shortwave trough digging south
into the northern high plains on Independence Day/Thursday.
Models all show 700mb temperatures as low as 0c to 4c as the
cold front pushes south into northern Wyoming Thursday morning.
Will need to monitor this front due to the possibility of late
night/early morning convection possible across the plains, and
much cooler temperatures for July 4th celebrations. With
significant timing differences and ensemble spreads, not very
confident in either of these scenarios, so kept highs in the 80s
with a mention of thunderstorms north of Interstate 80 for now.
Further out, all long range models seem to come into better
agreement after day 7...showing a strong 600dm upper level high
forming over the western Great Basin Region. Hot temperatures
are possible across the whole forecast area next weekend.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 532 PM MDT Fri Jun 28 2024
VFR conditions currently at area terminals with isolated
thunderstorms along a line from KLAR to KSNY late this
afternoon. These storms will continue over the next few hours
into early this evening, but any terminal impacts should be
brief and limited, therefore kept any mention to VCTS through
02z. Winds should begin to turn northerly later this evening
through Saturday morning with the expected frontal passage.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...SF
LONG TERM...TJT
AVIATION...MB
Area Forecast Discussion
National Weather Service Quad Cities IA IL
656 PM CDT Fri Jun 28 2024
.KEY MESSAGES...
- Isolated showers and storms are possible overnight into early
Saturday morning. SPC has a Slight Risk for severe storms
west of a line from Manchester to Cedar Rapids to Kahoka,
Missouri, and a Marginal Risk to the east.
- Another round of active weather will occur Monday through
Wednesday with several chances for showers and thunderstorms.
Heavy rain is possible each day.
- Moderate to Major flooding is expected on several area rivers.
&&
.SHORT TERM /THROUGH SATURDAY/...
Issued at 152 PM CDT Fri Jun 28 2024
At 2 PM, showers continue across eastern Iowa, northwest
Illinois and far northeast Missouri with thunderstorms over
Iowa, Keokuk, Jefferson, Washington and Henry Counties. Clouds
and rain have limited temperatures through the afternoon. At 2
PM, temperatures range from 67 degrees at Freeport to 75 degrees
at Keokuk. The heaviest rainfall amounts have been along and
north of the Highway 30 corridor where rainfall amounts over 1
inch have been reported.
The wave currently moving across the area is forecast to exit
into Illinois by bringing a break in the rain across the area.
Farther to the west along the Nebraska and Iowa border,
instability has increased where skies have been clear through
the day but is limited the farther east that you go. Models
continue to limit instability to near the cold front which is
forecast to move across the area from overnight into Saturday
morning. This instability will be tapped as a weak wave moving
to our north during the 9 PM to 4 AM timeframe. There has been
little change in the Storm Prediction Center Day 1 Outlook
through the day with a Slight Risk west of a Manchester Iowa to
Kahoka line and a Marginal Risk to the east. Little instability
is needed with 0 to 6 km shear near 45 knots. The HRRR
continues to be aggressive in the development of storms to our
northwest Illinois that moves across the area after 9 PM while
other models are more limited in the convective coverage and
intensity overnight. There remains low confidence in this
forecast but the potential remains in place for severe storms.
Based on current instability and model forecast and the timing
of the front during the overnight hours, think that ant storms
that develop this evening will be in a decaying as they move
across the area overnight. Think that the main threats will be
lightning, hail, and damaging wind gusts. Heavy rain remains a
possible given precipitable water values over 2.00 inches.
Probability match mean for rainfall shows a large spread among
the models in rainfall potential tonight with models having
anywhere between 0.40 to 1.50 inches.
The cold front is forecast to be in the vicinity of the
Mississippi River by 12 UTC Saturday with a continued threat for
showers and storms ahead of the front. Severe storms are not
anticipated. Dry air is slow to advect in behind the front but
dewpoints will be falling into the 60s through the afternoon.
High temperatures on Saturday are forecast to range from the
lower 80s along the Highway 20 corridor to the upper 80s in far
northwest Illinois.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
Issued at 152 PM CDT Fri Jun 28 2024
This weekend, we return to zonal flow aloft, becoming northwest flow
on Sunday, as a ridge builds over the Central US. Surface high
pressure will slowly traverse through the area during this time
period, exiting through the day on Monday. This timeframe will be
relatively quiet, weather-wise, which is welcomed. Saturday, we are
expecting temperatures to increase into the mid-upper 80s in our
southeastern half of the forecast area, with temperatures trending
near to slightly below normal Sunday and Monday. The warmer
temperatures Saturday will result from the slow-moving cold front
passing through the area that morning, allowing temperatures to warm
ahead of it. There will be a chance for showers and storms earlier
in the day, but as we approach the afternoon hours, we will see
chances drop off. From there, we will remain dry through Sunday and
much of Monday.
Monday night and into Tuesday, we see our first wave that is set to
impact the area this coming week. Much of the action with this seems
to be late Monday night, moreso during Tuesday morning, as the LLJ
takes much of the night to shift east over our area. Although, if
this system speeds up, we may see showers and storms earlier in the
night on Monday. This action will be associated with the leading
shortwave trough, with the bulk of the energy in our northern
forecast area. Thus, this will be the focus for higher
precipitation amounts and thunderstorm potential. It is too soon to
discuss deterministic amounts of rainfall, but we will see the
potential for heavier rainfall. Guidance is highlighting the
potential for high moisture content once again, with PWATs near 2.00-
2.50". Ensemble guidance remains quite low on probabilities for
rainfall, while deterministic guidance comes in quite aggressive
with precipitation. Thus, we will refrain from more details. Rather,
just be mindful that this can be a wet period, especially for those
in our northwest. The parent wave comes through Tuesday into
Wednesday, which will bring the chance for more heavy rain and
thunderstorms. As the cold front approaches that afternoon/evening,
moisture will pool along the boundary, with guidance highlighting
this being the timeframe with the highest PWATs. Thus, an increased
risk for higher rainfall rates.
Beyond that, guidance starts to diverge on the next system, with
large differences in timing and placement. While guidance seems to
favor the Thursday night into Friday timeframe for more precipitation,
will opt to refrain from any more details, as there is plenty of
time for this to change. In either case, it would seem that we will
approach the end of the work week with another round of showers and
storms for the area. All guidance highlights much of the end of the
week and into the weekend as an active period for rainfall.
Unfortunately, all of this rainfall will lead to further
fluctuations on the projected flooding along area rivers. Be sure to
stay up to date on local flood headlines!
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 645 PM CDT Fri Jun 28 2024
Periods of MVFR/IFR are forecast tonight into early Saturday
morning, with the lowest ceilings at CID and DBQ. Isolated
showers and storms will remain possible into Saturday AM, but
confidence on direct impacts to the terminals is low. BRL may
have a slightly higher chance for scattered storms late tonight
into early Saturday AM, but with low confidence on where (or if)
this round of convection develops, left thunder mention out of
the TAFs for now.
&&
.HYDROLOGY...
Issued at 1213 PM CDT Fri Jun 28 2024
Headline Changes:
Issued a flood watch for the Wapsipinicon River near De Witt due
to recent rainfall and QPF in the next 24 hrs. Upgraded Illinois
City LD 16 on the Mississippi from Moderate to Major flood
category.
Discussion:
Higher rainfall fell in the Wapsipinicon River basin than
initially forecast. As a result, the new forecast for the De
Witt gage has the river reaching flood stage in a little over 24
hrs. However, confidence in the placement of QPF tonight
remains too low to issue a warning at this time. Later shifts
will monitor trends and can issue if needed. The Cedar River
forecasts remain on track, with crests likely in the next 24
hours at Palo and Cedar Rapids. A secondary rise with a lower
crest than the 1st one, is now forecast on the Cedar due to the
1-2 inches that fell near the headwaters in the past 24 hours.
On the mainstem Mississippi, rises will continue at all sites
over the next 7 days. Higher rainfall amounts in southern MN
and northern IA in the past 24 hours has resulted in a quicker
forecast to Major flooding for many sites by approx. 36 to 48
hrs earlier, including Rock Island LD 15. Crests along the river
should begin to show up in upcoming forecasts this weekend
beginning with Dubuque LD 11. Barring any more heavy rainfall,
crests are anticipated in the July 4th-10th timeframe.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.
&&
$$
SHORT TERM...Cousins
LONG TERM...Cousins
AVIATION...Uttech
HYDROLOGY...Gross
Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
645 PM CDT Fri Jun 28 2024
.KEY MESSAGES...
- Strong to severe storms expected overnight, with damaging
winds, large hail, and heavy rainfall being the main hazards.
- Temperatures cool temporarily going into the weekend.
- Very hot and humid conditions expected to return next Tuesday.
&&
.DISCUSSION...
Issued at 106 PM CDT Fri Jun 28 2024
Early day storms and showers have mostly moved out of the region
at this point, leaving behind a cooler, moist airmass. Cloud
cover has persisted over much of eastern KS and MO throughout
the day, with some pockets evident on satellite. With these
conditions in place, the risk of severe weather tonight has
become more uncertain. This is in addition to the presence of a
strong capping inversion over the region. If cloudier
conditions continue, then the lack of warming to this airmass
may not destabilize it enough to create energetic storm modes.
However. with some clearing evident within the cloud shield,
there is a non-zero chance of severe development going into the
overnight hours.
With a cold frontal boundary forcing from a surface low and its
coincident upper level trough, a line of precipitation is set
to develop across NW MO and NE KS starting around the evening.
Models such as the NAM Nest and HRRR keep a line of storms
tracking over north-central MO, with the HREF keeping them
organized throughout the night. The likeliest period of impact
will begin at 7pm, with storms tracking southeast into midnight
tonight. Taking a look at forecast soundings before the line of
precipitation moves through, primary threats will be damaging
wind and large hail, with a layer of dry air aloft and a lower
freezing level. Lapse rates are forecast to remain lower around
6.5 degC/km, and forecasted shear values of 40-50 kts could
maintain stronger updrafts in any severe storms that form.
Irregardless of the severe threat, this line of storms will be
efficient precip producers (PWAT values ~2 inches across the
line), and will bring a threat of heavy rainfall to much of
central MO overnight. This will serve to exacerbate hydrologic
headlines in the region. By tomorrow morning, conditions should
become mostly clear as the complex exits towards the southeast
in full.
With the passage of this storm system, temperatures are expected
to fall in the upcoming days with the establishment of a surface
high bringing northerly winds and slightly cooler air to the
area. Afterwards, though, the propagation of this surface high
towards the east alongside its upper level ridge over the
southern CONUS will provide persistent southerly winds. With
these winds, temperatures are expected to rise once more to the
low 90s by early next week. Sporadic shortwave troughs embedded
within the upper level ridge`s flow will bring more
opportunities for scattered precipitation moving into next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 631 PM CDT Fri Jun 28 2024
Currently VFR at all terminals with southerly winds around 10
knots. Convection has initiated along the cold front over
eastern Kansas. These storms should progress eastward this
evening, likely impacting the terminals in the 2z to 7z time
frame tonight. There could be periods of heavy rain with VSBYs
dropping as low as IFR, along with a chance for hail and strong
wind gusts up to 55 knots. Winds should turn easterly and
eventually northerly by tomorrow morning, remaining at 10 knots
or less, with VFR conditions likely.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...None.
KS...None.
&&
$$
DISCUSSION...CDB
AVIATION...BMW
Area Forecast Discussion
National Weather Service Hastings NE
734 PM CDT Fri Jun 28 2024
...Short Term and Aviation Update...
.KEY MESSAGES...
- There is a Marginal (1/5) to Slight (2/5) Risk for severe
thunderstorms this evening for the area, with wind being the
main threat with any storms that are able to develop. A
Marginal Risk for Excessive Rainfall has also been put out for
the area.
- The weekend is looking pleasant with cooler temperatures and
periodic chances (20-50%) for showers and thunderstorms mainly
Saturday night through Sunday.
- The weekend is looking pleasant with cooler temperatures and
periodic chances (20-50%) for showers and thunderstorms mainly
Saturday night through Sunday.
- Areas north of Interstate 80 have been outlooked in a Day 4
risk area for severe weather by the Storm Prediction Center.
This will be something to keep an eye on as we get closer to
the event.
- Independence Day will be hot with highs ranging from the
mid-80s to low 90s. There is a 20-30% chance of showers and
thunderstorms.
&&
.UPDATE...
Issued at 734 PM CDT Fri Jun 28 2024
-- Various thoughts on thunderstorm/severe potential through
the rest of the evening-overnight:
- As largely expected, we have remained storm-free SO FAR this
evening, with robust severe storms along the very leading
edges of the synoptic cold front firing up "safely" southeast
of our coverage area (CWA) over northeast KS. Meanwhile, any
(so far weak) storms developing off the High Plains of the
NE/CO/KS border area have remained well to our west.
-- Between now and roughly 2 AM:
- Obviously the MILLION DOLLAR QUESTION is whether (and to what
degree) storms and possible severe weather will impact our CWA?
- Unlike last evening (when by now it was becoming quite clear
that we were not going to see much mainly due to stronger
capping), tonight`s capping situation is perhaps a LITTLE
weaker (but with 700 millibar temps still a good 12-13C).
Otherwise, the environment is certainly supportive of at least
isolated severe, with mixed-layer CAPE solidly 1500-2500 J/kg
and deep-layer/effective shear 40+KT (these parameters would
support east-southeast tracking supercells.
- Leaning on the last few HRRR runs as much as anything (usually
a reasonable bet in the very short-term), it has trended a bit
more aggressive with its depiction of isolated to perhaps
scattered storms (a few severe?) invading our western counties
9-11 PM, and then gradually weakening as they slide farther
east into our CWA between 11 PM-2 AM. Interestingly, the HRRR
focuses on two separate areas for greatest storm potential: 1)
one near/south of the KS border (which seems most reasonable
based on upstream radar trends)...2) another mainly north of
I-80, which seems a bit more questionable but also plausible,
as RAP forecast soundings suggest our northern zones will be
most prone to realizing elevated instability release around
1000 J/kg with storms based up around 750 millibars (these
would likely be more of a hail threat with perhaps penny to
quarter size potential). The former area near/south of the KS
border would (in theory) pose more of a damaging wind
threat...particularly if they organize a surging cold pool.
- PLEASE NOTE: because of residual capping/weak forcing aloft,
it is also quite possible that storm coverage/intensity again
"underachieves" this evening, which is why chances/PoPs have
been intentionally held UNDER 50% at this time.
-- After roughly 2 AM:
- In one change from previous forecast, have lingered/added at
least slight PoPs (20%) to the entire CWA through the late
night/early-AM hours, as both HRRR/NAMNest are now more
suggestive that at least isolated storms (possibly marginally-
severe?) could persist especially within counties along/north
of I-80 even through around sunrise.
- It is possible that small shower/thunderstorm chances may even
need lingered into the official Saturday daytime forecast
period (which starts at 7 AM) mainly in our northern zones,
but with higher-res models suggesting that even elevated
instability should be on a downward trend by then, will likely
defer to overnight forecaster to decide whether this is
warranted.
&&
.DISCUSSION...
Issued at 401 PM CDT Fri Jun 28 2024
The heat continues this afternoon across portions of south central
Nebraska and north central Kansas. Current temperatures are
primarily in the 80s to low 90s, with a cold front pushing through
the state. The front has moved through the Tri-Cities, with winds
mainly out of the north to northwest. A few showers moved through
the area earlier today, with additional chances mainly after 7PM.
Thunderstorms will start across the western portions of the area,
expanding in coverage to the east as the evening progresses. SBCAPE
of 2000+ J/kg, and MLCAPE of 1000+ J/kg are expected along with
DCAPE values of 1100+ J/kg, ML lapse rates around 7 C/km, and steep
low-level lapse rates in the west. The main concern for any severe
weather this evening will be wind. Some hail, an isolated tornado,
and localized flooding may also be a concern. The Storm Prediction
Center has outlooked portions of the area for either a Marginal Risk
(1 of 5) or Slight Risk (2 of 5) for tonight. The main areas of
concern for severe weather will be along and ahead of the front
(which includes the southern and western portions of the area.
Additionally, the Weather Prediction Center has outlooked us in a
Marginal Risk for Excessive Rainfall for this evening.
Heading into the overnight hours, thunderstorm chances (20-30%)
persist, with strong to severe storms not expected. The cold front
will bring in some cooler air for the weekend, making conditions
very pleasant. Expected high temperatures will range from the mid-
70s to low 80s for Nebraska and the upper 70s to low 80s for Kansas.
Lows will be primarily in the 50s and 60s on Sunday morning, and
the 60s on Monday morning.
As far as precipitation chances are concerned for the weekend, a few
showers and thunderstorms may linger into the morning on Saturday.
The rest of the day is looking dry, with additional showers and
thunderstorms late. Showers and thunderstorms will be possible
again on Sunday.
Monday, an upper ridge moves to the east, with southwest flow in
place over the High Plains. Temperatures are expected to climb with
warm air advecting into the region. The current forecast as most
areas in Nebraska in the 90s and north central Kansas in the 90s to
around 100 degrees. Heat index values may approach or exceed 105
degrees, which may result in heat headlines needing to be
considered. The heat is expected to continue into Tuesday,
although, slightly cooler temperatures are expected.
Periodic shower and thunderstorm activity is expected through mid-
week. Any one area may not see shower and thunderstorm activity
each day. The Storm Prediction Center has put out a Day 4 Outlook
for severe weather for areas along and north of Interstate 80. The
Weather Prediction Center has outlook the northeastern portion of
the Hastings CWA with a Marginal Risk for Excessive Rainfall.
For those planning on outdoor activities for Independence Day, there
is a 20-30% chance of showers and thunderstorms through the day.
Daytime highs are currently forecast for the mid-80s (north) to low
90s (south). Continue to monitor the forecast for the latest
updates.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 734 PM CDT Fri Jun 28 2024
For KGRI/KEAR Airports:
- General overview:
Odds strongly favor VFR ceiling/visibility and
rain/thunderstorm-free conditions through the vast majority of
the period. That being said, there will be at least a 3-4 hour
"window of opportunity" for thunderstorms later this evening
(perhaps strong to severe?), and there is also a low chance for
at least a brief MVFR ceiling late tonight behind a passing cold
front. Wind-wise, aside from any possible thunderstorm-induced
outflow, the overall-strongest breezes with gusts 20-25KT will
occur out of the north during the day Saturday.
- Ceiling/visibility/rain/thunderstorm details:
Although far from a "sure thing", there is just enough support
for the possibility of a broken line or cluster of thunderstorms
to pass through from west-to-east this evening, that have opted
to introduce a generic "vicinity thunderstorm" (VCTS) 02-06Z
KEAR/03-06Z KGRI. IF storms occur, there is a low probability
that they could be strong to marginally-severe, with the main
issue being strong outflow winds 40-50KT. Will closely monitor
this possibility and amend for possible TEMPO and/or prevailing
thunderstorm inclusion as needed. Beyond 06Z, there is still a
very low (around 10%) chance of spotty shower/weaker
thunderstorm activity through around 12Z, but this chance is
low enough to omit from TAFs at this time.
The other possible "wrench" in things are at least minor hints
of at least 1-2 hours of possible MVFR ceiling late tonight in
some (but not all) model data. Have "hinted" at this with a
SCT015 group 06-12Z, but far from enough confidence to go
prevailing MVFR at this time.
- Wind details:
Aside from any possible much stronger thunderstorm-related
outflow this evening, winds during these first 12-hours will be
fairly light (under 10KT out and mainly northerly). However, the
latter half of the period will be a bit breezy out of the north,
with the majority of Saturday daytime featuring sustained speeds
around 15KT/gusts 20-25KT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
UPDATE...Pfannkuch
DISCUSSION...Wekesser
AVIATION...Pfannkuch
Area Forecast Discussion
National Weather Service Grand Junction CO
555 PM MDT Fri Jun 28 2024
.KEY MESSAGES...
- Afternoon/evening showers and storms expected again today
though coverage and intensity will be less than seen over the
last few days.
- Drier air moves in Saturday for a brief downturn in shower and
storm activity though some convection is expected along the
Continental Divide. Temperatures will run around 5 degrees
above normal.
- Deep subtropical moisture returns Sunday onward, with a return
to widespread convection and increased chances for flash
flooding.
&&
.SHORT TERM /THROUGH SATURDAY/...
Issued at 204 PM MDT Fri Jun 28 2024
This mornings sounding reported 1.01 inches of PWAT here at the
Grand Junction airport. This matches up fairly well with
forecast amounts so subtropical moisture does continue to linger
across eastern Utah and the Western Slope. Much drier air can
be found to our north and west and has started advecting into
the area, however. Despite this intrusion of drier air, we can
still expect some afternoon showers and storms. Speaking of,
cells have just started popping across the CWA as forecast by
CAM models. Upper level support is lacking though there is some
weak divergence aloft that will help with lift outside of
daytime heating. SPC`s Mesoanalysis Analysis page is
highlighting widespread values of 500 to 1000 J/kg of CAPE, down
from 1500 J/kg that was showing up in earlier model runs. This
is good news as storms shouldn`t be as strong as what we`ve seen
over the past few days. The highest shear is found across the
northern half of the CWA and also across much of eastern Utah.
The 18Z HRRR run continues to show the best coverage to be north
of the I-70 corridor though some cells do fire over eastern
Utah and SW CO. In this environment, we will continue to see
some hail, gusty outflow winds and heavy rainers though not as
intense as what we experienced yesterday. The convection will
continue into the early evening hours before starting to weaken.
Thus, the Marginal Risk (5% chance for wind >= 58 mph and/or
hail >= 1 inch) for severe thunderstorms issued by SPC for the
northern half of our forecast area. Showers and a few storms
will likely persist for an hour or two after midnight before
dying off completely.
PWATs finally drop down to 0.6 to 0.8 inches across the area for
Saturday and CAM guidance is picking up on this downturn with less
convective coverage. Having said that, the higher terrain will be
favored for convective initiation with the San Juans and areas
along and around the spine of the Continental Divide also being
favored for showers and storms. The NBM agrees with slight
chance to chance there (20 to 50%) along the Divide but little
elsewhere. Probably underdone and may need to bring in the HRRR
or NAMNEST to bump PoPs for the remaining higher terrain. Will
change as needed. As the atmosphere will be drier than seen
today, gusty surface winds will be probable along with some
hail. Heavy rain will be possible as well, under and near the
strongest convection, but widespread heavy rain appears less
likely. Enjoy this reprieve, brief as it is, because the next
surge of moisture starts Sunday.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
Issued at 204 PM MDT Fri Jun 28 2024
The persistent monsoonal regime stays put Sunday and Monday, along
with the oblong high pressure anchored over the southern states. The
pending arrival of a PACNW trough nudges the subtropical moisture
plume eastward enough to keep some of our northern counties out of
the crosshairs. This doesn`t mean a dry forecast, because fringe
moisture interacting with a strong southwesterly jet max Sunday
afternoon should get things going on the terrain of the Tavaputs,
Flat Tops, Elkheads, etc. up there. Meanwhile down south, where the
moisture is best, there should be no problem with another round of
robust convection around the Four Corners, Central Mountains and the
San Juans. The trough axis works across the Great Basin Sunday night
and should keep some active weather going during the overnight hours
into Monday morning. Leftover cloud cover on Monday leaves some
forecast uncertainty to the level of convective instability we might
see. Moisture will remain abundant, as well as the presence of the
dynamic forcing under the now broadened open wave working across the
northern Rockies on Monday afternoon. For now, it`s best to expect
more monsoonal showers and thunderstorms for the forecast Monday and
likely Tuesday too. Shower activity Tuesday looks to turn down as
the upper trough moves eastward, kicking the subtropical return on
the high back onto the Plains and thereby dries us back out under
northwesterly flow spilling in from the PACNW. Another trailing wave
ripples through Wednesday with little new moisture to work with.
Remnant moisture will get worked on and likely spark a shower or two
down in our southern counties and along the southern Divide again. A
break in the unsettled weather pattern finally arrives in time for
Fourth of July festivities as the trough on the Plains suppresses
the high enough to shut off the monsoonal feed and introduce some
dry air from the northwest. This trend holds for Friday and perhaps
beyond as high pressure amplifies over the West. Temperatures surge
upward Sunday before cloud cover and precipitation bring them down
some Monday and Tuesday. The late week dry pattern should see the
return of warmer conditions as well. The big wheel of the monsoon
keeps turning. Stay tuned.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 555 PM MDT Fri Jun 28 2024
Scattered showers and thunderstorms continued to move eastward
north of the Roan Plateau into the Flat Tops with another area
of activity in the vicinity of KHDN. It appears likely that in
addition to storms in the vicinity, KHDN will likely see a brief
shower, though VFR conditions will persist. In fact, VFR
conditions are expected for all TAF sites during the next 24
hours and it`s unlikely that any of the other TAF sites will see
a thunderstorm threat. Gusty outflow winds with today`s storms
have been far less intense than yesterday with the highest
observed 45 mph. Storms will dissipate this evening with
clearing occurring overnight. The region will see fewer showers
and thunderstorms on Saturday afternoon. Winds will shift to a
light drainage flow toward late evening, switching to normal
upslope flow on Saturday afternoon.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...None.
UT...None.
&&
$$
SHORT TERM...TGR
LONG TERM...LTB
AVIATION...NL
Area Forecast Discussion
National Weather Service Grand Rapids MI
942 PM EDT Fri Jun 28 2024
.KEY MESSAGES...
- Showers and storms tonight into Saturday
- Dry and comfortable Sunday through Monday
- Unsettled and warmer much of the holiday week
&&
.UPDATE...
Issued at 942 PM EDT Fri Jun 28 2024
The 00Z run of the HRRR is quite startling in that it paints a
narrow swath of 4+ inches of rain overnight along the I-94
corridor between Kalamazoo and Jackson. There is a decent theta-e
surge and a low-level wind confluence axis that makes localized
heavy rain seem plausible. The 00Z SPC HREF Prob Matched Mean
(PMM) and Local PMM guidance should lend a bit more insight once
it becomes available in the next hour or two.
Not going to completely bite on a single deterministic run at
this point, but certainly there is some concern since this could
cause pronounced localized flooding should this come to pass.
Otherwise, no changes to the forecast planned in terms of overall
coverage and timing of anticipated thunderstorms.
&&
.DISCUSSION...
Issued at 337 PM EDT Fri Jun 28 2024
- Showers and storms tonight into Saturday
Some light rain is falling in places this afternoon across
Southwest Michigan. This rain is falling from high cloud bases
that from the most part are above 5,000 feet. This precipitation
is associated with a weak shortwave moving through the area as
well as the initial surge of moisture advection.
The most substantial rainfall will occur tonight into Saturday as
an upper trough digs into the northern Great Lakes driving a cold
front through the area on Saturday. Instability tonight is not all
that substantial, but on the order of 500-1000 j/kg. The HREF
would suggest some embedded storms within a broader area of rain
showers. Not expecting anything close to severe tonight given the
limited instability. We are likely looking at 0.25 to 0.50 inch
rainfall amounts in many areas tonight with local amounts towards
an inch in the heavier swaths.
On Saturday the cold front will bisect the area at daybreak with
storms mainly expected southeast of a Holland to Clare line. As we
work through the day, the best chance for storms in the afternoon
and early evening will be near and south of I-96. Showers and
storms on Saturday will be a bit more transient so rainfall totals
will be lower, ranging from trace amounts to 0.30 to 0.40. We are
in a SPC marginal risk for severe weather, but we expect
instability to be muted by clouds and morning precipitation.
Chance for any severe weather look low.
HREF tries to indicate some scattered showers and storms moving
back into Central Lower Michigan during the late afternoon and
evening ahead of the main upper shortwave. This activity will be
scattered and given the drier air moving in we have a lower
confidence in this occurring. There are hints at some lower clouds
developing Saturday night in the wake of the precipitation. We
have brought some of these clouds into Central Lower Michigan at
this time.
- Dry and comfortable Sunday through Monday
After the unsettled weather in the first couple of periods of the
forecast, the area will see dry weather and cooler temperatures make
their way over the area for Sunday and Monday. This will be the
result of a fairly decent upper ridge and Canadian sfc high moving
over the area. This will provide for strong subsidence to cap any
clouds that try to grow at all in the vertical. 850 mb temperatures
on Sunday around 7 to 9C will support max temperatures in the low to
mid 70s. Return flow setting up on Monday will support highs in the
upper 70s.
- Unsettled and warmer much of the holiday week
The upper ridge responsible for the dry weather Sunday and monday
will slip east of the area by Tuesday. This will allow a long wave
trough over the Pacific NW to move over the upper midwest. Deeper
flow from the SW will bring warmer and more moist air to the state.
Embedded short waves in the flow will bring multiple chances of
showers and a few storms to the area for Tuesday and Wednesday.
Details at this point are obviously a bit up in the air, but we can
expect temperatures to warm back into the 80s with more humid air,
and occasional chances for rain.
There has been some decent agreement that much of the wet weather
may settle just south of the area on the Holiday. The short waves
moving through Tuesday and Wednesday flatten out the upper jet a
bit. They will also lay out a front that looks to stall out over the
southern portion of our area, or just south of the state. This will
take the better chances of rain further south. However, this could
end up being a scenario where waves ride along the front, and MCS
activity just north of the front could be found. For this reason,
small rain chances will be maintained for the holiday.
The uncertainty by next Friday with respect to frontal and wave
positions will obviously be fairly high due to the sequence events
that takes place leading up to then. There is some hint that maybe a
short wave ridge may build in on Friday in the wake of the early
week trough, and the next trough reloading over the western portion
of the country.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 756 PM EDT Fri Jun 28 2024
Regional radar shows thunderstorm development across central
Wisconsin where MUCAPE values of around 1000 J/kg are present. We
do not achieve those values until mainly after 06z and especially
after 09z. As such, there is no mention of VCTS until then for the
terminals. A consensus of high resolution models indicates good
confidence for lowering ceilings into the IFR category ahead of a
frontal boundary, namely in the 12z to 18z window across the
region, when ceilings were trended down below 1000 ft. Afternoon
thunderstorm redevelopment may occur ahead of and along the cold
front mainly late, but confidence is not high yet on timing or
coverage.
&&
.MARINE...
Issued at 337 PM EDT Fri Jun 28 2024
We have extended the current Small Craft Advisory (SCA) through
800am on Saturday from Grand Haven northwards. South winds of 15
to 25 knots will produce marginal SCA conditions of 3-5 feet
tonight. The highest waves per the WaveWatch3 model look to remain
offshore which is why we do not have a corresponding Beach Hazards
Statement (BHS) out.
After tonight, the focus will shift to our next wave event which
develops behind a cold front Saturday night and Sunday. 4 footers
develop just after midnight Saturday night and will continue
through the day on Sunday. Waves will peak on Sunday morning in
the 4 to 6 foot range. A SCA and BHS will be likely on Sunday.
That said, weather conditions will not be ideal for a beach day
with water temperatures in the 60s (and falling). Air temperatures
on the beach will likely hold in the 60s as well, so we are not
expecting a high beach population and even less so in the water.
A north wind is the direction that are biggest upwelling occurs
with. As a north wind commences, each layer below the surface
turns a bit to the right due to Coriolis. Therefore the general
flow below the water surface (in a north flow above the water) is
offshore and upwelling occurs. So, with air temps in the 60s and
falling water temperatures we are not expecting lots of people in
the water. We will message it with full force on Saturday a day
ahead of the actual event.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 8 AM EDT Saturday for LMZ847>849.
&&
$$
UPDATE...TJT
DISCUSSION...Duke/NJJ
AVIATION...Hoving
MARINE...Duke
Area Forecast Discussion
National Weather Service Gray ME
1108 PM EDT Fri Jun 28 2024
.SYNOPSIS...
High pressure over the region tonight will push south and east
of New England on Saturday with a warm front lifting through the
area by late in the day. This will result in increasing chances
for showers by late Saturday with rain and embedded
thunderstorms Saturday night. Rain will taper off early Sunday
ahead of an approaching cold front with the potential for
additional showers and thunderstorms Sunday afternoon. High
pressure arrives early next week bringing a period of quiet
weather and seasonable temperatures.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
1100 PM Update... Minor changes to reflect latest observational
trends. Cirrus will continue to increase overnight with lows
into the 40s and 50s.
Previously...
715 PM Update... A rather pleasant Summer evening continues
across the region with mainly clear skies and warm temperatures.
Latest satellite imagery indicates the cirrus shield is still
rather far away in VT and Quebec and therefore given the low dew
points and weakening winds, temperatures will likely fall
rather abruptly over the next few hours. Will continue to
monitor these cloud trends and the associated impacts to
overnight lows.
Previously...
High Impact Weather Potential: None.
Pattern: The shortwave trough responsible for ushering in a much
cooler and drier airmass is now moving east of the region as seen on
early afternoon GOES 16 water vapor imagery. Surface high pressure
now over southern New England will slowly sag south and east
offshore with the flow aloft slowly backing ahead of the next
shortwave arriving into the Great Lakes region. Overall this spells
a quiet night weather-wise with the focus of the forecast being on
cloud cover and overnight lows.
Through this evening: Temperatures should quickly drop in the dry
airmass with some high clouds overhead. 8pm temperatures will dip
below 60 in the mountains while remaining in the 60s to the south.
Tonight: High pressure settles south and east of the area overnight
as warm advection pattern sets up in the return flow as the H8 ridge
axis passes to our east. The result will be top-down saturation
with mid and upper level cloudiness increasing. The result will be
somewhat warmer temperatures with lows generally in the 50s across
the area under light winds.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
High Impact Weather Potential: Locally heavy rain possible Saturday
night.
Pattern: Low pressure north of the western Great Lakes early
Saturday will move north and east through the short term forecast
period remaining well north of New England through Saturday night.
Saturday: Southwesterly flow continues to strengthen during the day
as surface warm front approaches the region from the southwest. Top
down saturation will continue through the morning with ample dry air
remaining below H85. By late in the day...there is good short term
mesoscale ensemble agreement that some showers will work into the
northern zones given continued isentropic ascent in the area of
deepest moisture. No convection expected with no instability to
work with through evening. Despite warm advection...the southerly
marine-influenced flow along with increasing clouds will not yield
any significant warming of surface temperatures with highs again
around 70 in the mountains and in the lower 70s to the south. Some
of the mesoscale guidance is hinting at the midcoast through the
Capitol region also struggling to reach 70.
Saturday Night: Robust...broad LLJ at H8 crosses the New England
Saturday night with MUCAPE plume overspreading the region as the
warm front finally drives through northern New England. This occurs
in the presence of significant deep moisture...with PWATs around 2"
pushing above the 30 year climatology values. Deep forcing is a bit
more questionable. There is a weak mid level vort max in the
presence of weak height falls with modest right entrance region jet
forcing moving overhead overnight in advance of the surface cold
front. Thus...despite increasing warm cloud depths in the presence
of significant moisture...the overall ensemble signals for heavy
rainfall have decreased over the past 24 hours...favoring areas
across northern New York. A consensus forecast approach favors basin-
wide average QPF of 0.5 to 1"...which also lines up well with the
most recent runs of the HRRR and NAM Nest. Certainly some potential
for locally heavy downpours given the environment focused over the
mountains matching well with the day 2 marginal excessive rainfall
outlook from WPC. Temperatures will be much warmer than the night
previous as the warm front lifts through the region with southern NH
likely to remain in the upper 60s...with upper 60s to lower 60s
elsewhere across northern New Hampshire and western Maine.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
I suppose its safe to say we have worked our way into a typical
summer pattern as 500 MB ridging take residence S of the Mason-
Dixon line, and troughs in north-shifted jet stream. Are
generally flatter and more mobile. We start off a little on the
cool side but the trend will be fore warming to near and above
normal 850 MB temps by mid to late week. The tricky part is what
becomes of the closed low that shifts to our SE late in the
week and whether it acts as a block to allow S_SW flow to
settle, making for another round of hot/humid weather or keep
flow more zonal which will lead to more typical summer wx. As
for chances of shra/tsra, beyond Sunday, we do see some of wave
move to our N around Wed-Thu.
On Sunday will see a cold front, trailing fro low pressure
moving just N of the St. Lawrence valley cross the CWA. 12Z Euro
shows a generally less dynamic system aloft associated with the
front, but there should be a surge in low level moisture and
instability ahead of it Sunday morning, so cannot rule out
SHRA/TSRA, although less certainty about the potential for
severe that day. Behind the front, we do a surge of cooler air,
and very dry air at least for Mon-Tue, with highs a little below
normal on Monday, but nice otherwise, and warming back to near
normal on Tuesday. Wed will be warmer still with a bit of
increase in humidity, but should stay dry most of the day.
Wednesday night and Thursday are the next chance of precip, but
theres still a lot of uncertainty with this weaker system.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
Short Term...
Summary: High pressure builds south and east of the region tonight
with southerly winds strengthening on Saturday as clouds slowly
lower. A warm front crosses Saturday evening with deteriorating
conditions in rain and embedded thunderstorms.
Restrictions: VFR conditions expected to dominate through the day
Saturday. Showers with embedded thunderstorms arrive Saturday night
with conditions deteriorating to MVFR/IFR CIGS and MVFR VSBYS.
Winds: Northwest winds 10g18kts will diminish through this evening
before going calm/light-variable for the overnight. For the day on
Saturday winds turns southerly and strengthen to 10g18kts for the
day. Winds remain southerly around 10kts for Saturday night.
LLWS: LLWS is not expected through Saturday. Saturday night...a
strengthening low level jet will result in LLWS throughout the
region.
Lightning: No lightning is expected through Saturday. Showers with
embedded thunderstorms are expected across the terminals Saturday
night.
Long Term...Mainly VFR Sun-Wed, although some restrictions
possible in SHRA/TSRA Sunday. Also valley fog possible at
KHIE/KLEB Sun and Mon night.
&&
.MARINE...
Short Term...Quiet conditions over the waters through early
Saturday as high pressure crests over the waters. Southerly
winds strengthen Saturday afternoon and Saturday night with SCAs
likely necessary for this period.
Long Term...SW flow ahead of cold front will allow for SCA conds
on Sunday, but these4 drop off Sun night, and stay below SCA
levels through mid-week.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory from noon Saturday to 4 PM EDT Sunday for
ANZ150>154.
&&
$$
NEAR TERM...Tubbs
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
904 PM CDT Fri Jun 28 2024
.KEY MESSAGES...
- Thunderstorms will bring beneficial rain to most of central
Illinois late tonight. The risk for severe weather remains low
(only around 5%).
- There is only a 20-30% chance for thunderstorms Saturday. Once
again, the severe risk is low (around 5%).
- Drier, cooler, and less humid conditions evolve Saturday night
through Monday; ideal for outdoor activities.
- The relief from the heat and humidity will be brief as it makes
a return by the middle of next week along with daily chances
for rain starting Wednesday lasting into the holiday weekend.
&&
.UPDATE...
Issued at 904 PM CDT Fri Jun 28 2024
Updates this evening to decrease PoPs as an outgoing shortwave
drifts off to the northeast with light showers tapering off behind
the feature. Also, lowered overnight PoPs.
A couple of bands of showers have been organizing closer to a
cold front from the upper Midwest to the southern Plains, with
the stronger activity taking place west of I-35 nearest the
surface cold front. Mesoanlysis products based on the RAP model
depict an axis of strong instability around 4000 J/kg just ahead
of the cold front, trailing off to a couple hundred or less along
the Mississippi River. A couple of 00Z high resolution model runs
just coming in are following a trend of weakening pre-frontal
convective bands shifting into central IL overnight, as well as
keeping activity more scattered and disorganized. May need
additional updates later to delay onset of higher PoPs, which
currently shift into the area around midnight.
37
&&
.SHORT TERM... (Through Late Saturday Night)
Issued at 258 PM CDT Fri Jun 28 2024
At 230pm, day cloud phase distinction satellite shows scattered mid
(mostly supercooled water, as the freezing level is >14,000 ft!) and
high-level (ice) clouds across central Illinois, with scattered
convection upstream across southeast Iowa where low level moisture
transport is strong ahead of a shortwave trough. Current suite of
CAMs suggests this wave of thunderstorm activity will gradually
weaken as it becomes displaced from better instability and shear in
west central/northwest Illinois, though this forecaster wasn`t
confident enough to completely eradicate all mention from the
forecast this evening; hence, 25-50% PoPs remain northwest of I-55
this evening.
The better chance (60-80%) for precip will arrive later tonight, as
storms developing closer to the upper-level forcing drift into our
area while simultaneously weakening. It`s uncertain whether we`ll
wind up with any hydrological or convective (wind, hail) issues
tonight, but the CAMs continue to advertise the greatest
thermodynamics to our southwest where storms developing along the
northern periphery of the instability axis/LLJ across central/east
Missouri may rob our region of any appreciable CAPE. Nonetheless,
our morning sounding revealed a PWAT of 1.62 (near the
climatological 90th percentile), and given continued warm/moist
advection those values may surge to nearly 2 inches overnight -
more than enough for efficient rain producers (especially given
the depth of the warm cloud layer). NBM suggests the greatest
chance (20-35%) for rain amounts surpassing 1 inch will be
generally west of a Galesburg to Taylorville line, where some
guidance even depicts some highly- localized 2+ inch totals.
Precip loading could also contribute to downward momentum
transport fostering gusty winds in the heaviest cells, especially
if we struggle to decouple given continued mixing via the LLJ. In
general, the severe risk appears low, with SPC maintaining just a
level 1 of 5, marginal (5%), risk for severe weather.
That holds for tomorrow as well, though tomorrow the reason for the
marginal risk is slightly different. Recovery of instability (HREF
mean is 1500-2500 for SBCAPE) in our area is well forecast by the
12z CAMs, though none of them are particularly aggressive in
redevelopment of storms along/ahead of the cold front. If storms
should develop, the unstable airmass would favor severe wind/hail
with them, though at this point only about 20-30% of guidance shows
redevelopment during the afternoon. We`ll be keeping a close eye on
model trends for this activity.
Tomorrow evening, quite the impressive cold front for this time of
year will sink southward across central Illinois, bringing a quick
drop in humidity (dewpoints are forecast to drop 15+ degrees, from
mid 70s to upper 50s, in the span of 1-2 hours) and increase in wind
(northwest gusts are forecast to reach 30+ mph). By Sunday morning,
our northwest counties are likely to drop into the mid-upper 50s,
while south of I-70 some spots might still be hovering around 70.
Bumgardner
.LONG TERM... (Sunday through Next Friday)
Issued at 258 PM CDT Fri Jun 28 2024
A brief stretch of unseasonably cool and dry weather is on tap for
Sunday and Monday as a strong mid to upper level ridge will be
building to our west over the Great Plains. Unfortunately, the
pleasant stretch of weather will be short lived as the ridge axis
passes through by Monday evening, placing us back under a southerly
flow regime once again by Tuesday. A weak mid level shortwave, that
is expected to traverse across the Upper Midwest Tuesday night into
Wednesday, may provide enough forcing aloft to support some rain.
With the depth of moisture still in question, especially east of I-
55 in Illinois, only chance PoPs remain for most of the area on
Wednesday. The 00z LREF members are in good consensus that the same
upper level ridge that will bring us our cool down Sunday and Monday
will setup over the SE CONUS, with 500mb heights of 594dm. The
current placement of this 594dm heat dome puts us under the "ring of
fire", giving us 30-50% PoPs daily from Wednesday through the end
of the extended.
With deep northwesterly flow aloft, along with rising heights,
Sunday and Monday will be dry and unseasonably cool with widespread
highs in the 70s. The coolest night in the next 7 days will be on
Sunday night when lows are expected to drop into the 50s, bringing a
springtime like chill back to the area. With southerly flow
returning by Tuesday, temps will be on the rise with highs reaching
the upper 80s to lower 90s on Tuesday and Wednesday along with
dewpoints reaching the lower 70s. The combination of heat and
humidity will result in heat indices nearing or exceeding 100
degrees in some locations on Tuesday and Wednesday, especially south
of I-70 in Illinois on Wednesday. Confidence in temps Thursday and
Friday is lower due to the uncertainty in the strength and position
of the nearby heat dome by the end of next week.
Peine
&&
.AVIATION... (For the 00z TAFs through 00z Saturday Evening)
Issued at 642 PM CDT Fri Jun 28 2024
Scattered showers will continue for an hour or two to start the
TAF forecast period, but there is little chance of significant
impact in terms of low cigs, vsbys, or thunderstorms. After a few
hours, a line of thunderstorms is expected to organize to the west
and sweep into the area by 05Z-07Z, and exit the central IL
terminals by 09Z-12Z. This will likely be accompanied by brief
MVFR cigs and vsbys. Following the departure of these
thunderstorms, a period of MVFR cigs is expected from around
15Z-21Z before low cloud cover lifts and scatters out. Winds S
around 10 kts, shifting to W after 15Z.
37
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Indianapolis IN
814 PM EDT Fri Jun 28 2024
.KEY MESSAGES...
- Rain showers/isolated thunderstorms overnight and early Saturday
- Becoming partly sunny on Saturday afternoon.
- Cooler Sunday and Monday, heat returns on Tuesday and Wednesday.
- Rain/storm chances return Wednesday onward.
&&
.FORECAST UPDATE...
Good confidence in forecast trends regarding incoming convection,
mainly overnight into Saturday. Warm and moist advection ahead of a
weak upper wave in zonal flow along with sufficient instability will
result in convection moving in from the northwest overnight as Hi-R
es soundings show the low levels moistening. CAMs in good agreement
on convection becoming widespread after 08z. Currently, some weak
echoes in westerly flow will necessitate chance PoPs from around a
Clinton to Fishers to Muncie line before Midnight. Lightning
detection equipment was not detecting any lightning over the region
despite some very weak instability.
The southerly winds and overcast conditions and dew points rising
into the lower to middle 70s suggest that will be the bottom of
overnight lows.
&&
.SHORT TERM (This evening through Saturday)...
Issued at 258 PM EDT Fri Jun 28 2024
Surface analysis early this afternoon shows strong high pressure
centered over eastern NY and NJ. This high was influencing the
weather across the eastern third of the country, including Indiana.
The high was providing southeasterly to southerly flow across
Central Indiana. Surface low pressure was found over NB. Warm and
moist southerly flow was found streaming northward through the
Mississippi river valley, where abundant cloud cover was found. This
cloud cover was advecting east toward central Indiana. A large area
of showers with a few thunderstorms were found over IA/Northern IL
and MO. Water vapor imagery showed a mainly zonal flow in place
across the CONUS, with a wave of moisture in place from the southern
plains to middle Mississippi valley to the western Great Lakes. A
short wave within this flow was found over SW MO. Dew points across
central Indiana were mainly in the lower 60s.
Tonight...
Models suggest that within the upper flow several weak upper
disturbances will pass across Indiana tonight and on early Saturday.
Meanwhile within the lower levels the low pressure system over NB
pushing toward the Great Lakes tonight dragging an elongated cold
front across the Mississippi Valley toward Central Indiana. Forecast
soundings this evening remain dry as these features approach.
However the forecast soundings show deeper saturation arriving after
09Z with pwats near 2.25 inches. Instability appears quite limited
as CAPE remains mainly below 500 J/KG. HRRR shows showers mainly
arriving after 08Z, then passing into the forecast area by 12Z. Thus
will have a dry forecast this evening, but begin ramping up pops
overnight as the forcing and moisture begin to arrive in the area.
Confidence for rain is high. Given the expected clouds and
precipitation and the cold front not passing until after 12Z expect
lows in the lower 70s, with some middle 70s south.
Saturday...
Models suggest that at 12Z forcing and the associated cold front
will be over Central Indiana. This should then continue to exit to
the east through the morning hours on Saturday, with the focus
mainly along and south of an I-70 line. By 18Z, forecast soundings
lose their deep saturation and winds become westerly in the wake of
the cold front. Aloft forcing is lost as it pushes east by the
afternoon. Again, instability appears limited as little CAPE is
available, however a stray thunderstorm cannot be ruled out. Thus
will continue high pops through the morning hours, mainly across the
southern half of the forecast area and trend toward a dry forecast
by afternoon. Minimal overall temperature advection is expected
until Saturday night. This will lead to a quick recovery of high
temperatures on Saturday afternoon to the middle 80s.
&&
.LONG TERM (Saturday night through Friday)...
Issued at 258 PM EDT Fri Jun 28 2024
Generally quiet weather through much of the long range as broad
ridging takes hold early next week. Rain chances return late in the
period.
Saturday Night and Sunday
Any lingering showers from Saturday`s cold front / shortwave will be
slowly exiting the area by Sunday morning. Much cooler conditions
will follow, as surface high pressure builds in from the north.
Model temperatures in the 850mb level drop to around 11C in most
guidance, with some members showing as low as 8C by Sunday night.
Around the same time, the surface high moves directly overhead with
large-scale subsidence. Clear skies, light winds, and a cold air
mass should promote temperatures well-below normal Sunday night into
Monday morning. Lows should drop well into the 50s with perhaps some
rural areas dropping into the 40s. Normal lows are around 65 for
this time of the year.
Monday Onward
Cooler than average temperatures linger into Monday with highs
climbing into the 70s for the most part. A few locations may reach
80, especially further south away from the core of the now-departing
cold air mass. As high pressure slides eastward, low-level flow
turns southerly and a warming trend looks to commence. By Tuesday,
850mb temps rise by about 5-10 degrees, which under full sun and
efficient mixing corresponds to highs in the mid to upper 80s. The
primary axis of warm air advection remains to our west, however.
This warm air advection enables a ridge to build over the Plains
which then drifts eastward through the week. As such, generally
above-normal temps in the upper 80s / low 90s should persist through
the remainder of the week. Low temps should also be a bit above
normal, reading in the high 60s to low 70s for most locations.
Turning our attention to precipitation chances, we`ll see quiet
weather associated with high pressure persisting through Tuesday.
Most guidance shows a cold front attempting to infiltrate the
aforementioned ridge by Wednesday night or Thursday. This front
combined with increasing humidity from the south could allow for
repeated shower/storm chances. Ensemble guidance shows the ridge
axis moving eastward a bit allowing flow to be south/southwesterly
through the column across Indiana. Since the front is diving down
from the northwest and encountering largely boundary-parallel
flow...most guidance stalls the front somewhere nearby (most show
central or southern Indiana). Shower and storm chances could then
linger through the rest of the week if this is the case.
Ensemble guidance is in fairly good agreement through Wednesday but
diverges thereafter. And this is probably due to how individual
members handle the front impinging on the departing ridge.
Therefore, confidence in forecast temperatures and precipitation
decreases by late Thursday and Friday.
&&
.AVIATION (00Z TAF Issuance)...
Issued at 543 PM EDT Fri Jun 28 2024
Impacts:
- VFR expected for the bulk of the TAF period.
- Showers with isolated TSRA after 07Z.
Discussion:
A cold front will drop southeast across the terminals Saturday
afternoon. The front will interact with a deepening column per Hi-
Res soundings and an upper wave and result in widespread showers
overnight and into Saturday morning. A few lightning strikes are
also possible. The showers will be dissipating and ending late in
the day.
Winds will be SSW 10 knots or less.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...MK
SHORT TERM...Puma
LONG TERM...Eckhoff
AVIATION...MK
Area Forecast Discussion
National Weather Service Northern Indiana
728 PM EDT Fri Jun 28 2024
.KEY MESSAGES...
- Heavy rain and thunderstorms are expected overnight, with isolated
flooding/ponding possible in fields and on roads. A few storms late
morning/early afternoon on Saturday could be strong to severe, with
damaging winds and a brief tornado or two. The best severe chances
will be in NW Ohio. (Medium confidence)
- A second round of storms could develop later in the
afternoon/evening Saturday, with damaging winds as the main threat
(Low confidence, depends on if recovery happens behind the morning
round of storms).
- Hazardous swimming conditions are expected on Lake Michigan on
Sunday. Waves 4 to 7 feet and dangerous rip and structural currents
are likely. Stay out of the water and stay off of the pier!
- Dry with near normal temperatures Sunday through Tuesday
morning.
&&
.DISCUSSION...
Issued at 215 PM EDT Fri Jun 28 2024
Stay weather aware overnight and into the day tomorrow as strong to
severe thunderstorms are possible within two rounds of storms. SPC
has maintained a Slight Risk (level 2 of 5) for much of our area.
GOES visible satellite shows increasing cloud cover moving in from
the west as a warm front advances across our forecast area. Dense
cloud cover persists through tonight along with a chance of showers
this afternoon and evening. Overnight and into Saturday morning, a
line of heavy rain and embedded thunderstorms is likely to develop
after midnight along a pre-frontal trough. As convection moves
eastward into far NE Indiana and NW Ohio, it is likely to intensify,
with a few strong to severe storms possible in the morning and early
afternoon. Hi-res model guidance varies in coverage and intensity of
storms, with the NAM and HRRR showing the best severe potential.
Southwesterly winds behind the warm front will advect moisture
into the area overnight, which will yield an unstable
environment for storms to form. 1500-2000 J/kg MLCAPE is
possible coinciding with 30 kts of 0-6 km shear orthogonal to
the pre-frontal trough. Low to mid level lapse rates throughout
the day Tuesday will be around 6C/km. In addition, there is
favorable 0-1 km SRH of 150-200 m2/s2. Damaging winds 40 to 60+
mph and a brief tornado or two will be possible. The best
severe chances in the morning will be where the Slight Risk is
in NW Ohio, although I wouldn`t surprised if a strong to severe
storms develops along or just east of the I-69 corridor. There
is increasing confidence in heavy rainfall and localized
flooding around midday Tuesday as record PWATs around 2 inches,
a deep warm cloud layer, and saturated low to mid levels of the
atmosphere will yield very efficient rainfall rates of 1-2
inches per hour in any storms. A cold front will come through
Saturday evening and there is low confidence in a second round
of storms developing along the front. Should a second round of
storms materialize, damaging winds 40 to 60+ mph will be the
main threat.
Hazardous swimming conditions are expected on Lake Michigan Sunday
thanks to gusty northerly winds behind the cold front. Waves will
build to 4 to 7 feet and wave periods look to stay in the 6-8 second
range (relatively high for Lake Michigan) thanks to a long fetch
down the lake. This will increase the probability of dangerous
currents, including rip and structural currents. Will hold on any
headlines for now but subsequent shifts will likely need to issue a
Beach Hazards Statement for Sunday into early Monday, as longer wave
periods and high waves may lead to current activity that persists
even once wave heights diminish. Those planning to visit the beaches
this weekend should stay out of the water and stay off of the pier!
It will be mostly dry and cooler with highs in the upper 70s to mid
80s Sunday through Tuesday morning as high pressure builds in at the
surface beneath a brief upper level ridge. Clouds move out of the
area bringing clear skies for Sunday and Monday. The next chance for
rain/storms will arrive on Tuesday afternoon/evening.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 727 PM EDT Fri Jun 28 2024
A warm front moves northward tonight bringing increased moisture to
the area. With a few shortwaves moving through overnight tonight
expect times of rain tonight mainly through mid to late morning
Saturday. An initial dry layer will cut into rain intensities and
keep conditions VFR until later in the TAF period. Have MVFR
conditions at the TAF sites starting around 13 or 14z. If VISBY
reductions occur, it would likely be with the rain in the mid to
late morning time period and at SBN, but chances with that are small
so will leave that out of the TAFs for now. As we head to the
afternoon, we begin to lose forcing and the precipitation coverage
and intensity should drop as a result. However, expect winds gusts
to increase to 20 to 25 kts as dry advection ensues. TAF shear is
very marginal, but there is a period between 7 and 12z that may
become conducive to LLWS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Johnson
AVIATION...Roller
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1046 PM CDT Fri Jun 28 2024
.KEY MESSAGES...
- Showers and storms end this evening over/near southeast MN
with a dry and seasonably cool weekend to follow.
- Unsettled weather expected Monday into Tuesday, with heavy
rain and some severe storms possible.
- Next potential active weather period is the 4th into the 5th, though
model spread remains high (and forecast confidence low)
during this timeframe.
&&
.DISCUSSION...
Issued at 335 PM CDT Fri Jun 28 2024
Surface analysis this afternoon shows a surface low up between
Bemidji and International Falls, with a cold front trailing to the
south from the low down to about Fairmont at 230pm. We`ve seen
extensive cloud cover through the day, which has held down
temperatures, but a plume of 70+ degree dewpoints has managed to
crawl its way along the front up to just west of the metro. This
moisture has allowed mlCAPE values to build to over 1000 j/kg along
the front from about Litchfield on south into Iowa. Along this
instability axis, we`ve see a weak line of storms develop along
the I-90 corridor down into Iowa. Over the next few hours, this line
of storms will continue to slide east toward La Crosse, with limited
expansion to the north expected. The strongest h85 winds are off to
the east of our area, so we have limited low level shear. Still, mid-
upper level winds will be strong enough to support 40-50 kts of deep
layer shear, so enough deep shear is present to support a low end
severe risk. From the 1630z Day 1 outlook, where the SPC has a 2%
tornado probability up into southeast MN captures where the greatest
likelihood of seeing some stronger storms will be through the
evening.
As we go through tonight, the cold front will push off to our east,
but that does not end our precipitation chances. This afternoon,
there`s an h5 low moving into wrn NoDak and as this moves east
through the night, we`ll see the threat for scattered showers and
maybe an isolated thunderstorms across central Minnesota. For the
rest of the weekend it should be mainly dry, but you can`t
completely rule out some isolated showers on Saturday as the last
piece of upper level energy moves through. Surface temperatures will
be cool and the atmo drying out, so we continue to keep PoPs below
15% (which keeps a precip mention out of our point-and-click
forecasts), but if things end up as robust as the 18z HRRR shows, we
may need to add in some -SHRA mention to the forecast for Saturday.
Big thing for Sunday is with the high overhead and the cooler highs
on Saturday, lows Sunday morning will fall into the 40s for all but
the urban core of the Twin Cities metro.
Next up on the weather system merry-go-round comes Monday into
Tuesday. Meso scale difference remain, but on the large scale, we
see the models bringing two shortwaves across the area. The first
goes from the Dakotas into northwest Ontario Monday/Monday night,
with the main trough swinging through the upper MS Valley on
Tuesday. It`s the first one that will likely pose the greatest
issues hazardous weather wise as it will send a 50-60 kt LLJ across
the area Monday night. Upstream of this LLJ, we`ll see 1000-1500
j/kg of MUCAPE feeding into this LLJ, which will result in another
heavy rain threat Monday night. The severe threat Monday is a
little more questionable given the threat for extensive cloud cover
and WAA rain to limit surface based instability, but if we see
surface features progress as far east as the ECMWF has them Monday
afternoon, then a severe risk extending a little farther east than
what the SPC Day 4 outlook has will be possible. Going ahead to
Tuesday, another round of showers and storms looks likely ahead of
the main trough, but where surface features are at that point will
determine where the greatest severe/heavy rain risk will be, but we
are seeing the potential for one more round of showers Tuesday
afternoon before this system departs to the east. Where the second
round of precip ends up will help determine what final rainfall
amounts look like, but the EPS mean QPF does have near 2" of rain
over southeast MN. When looking at the individual members at RST,
you do see a handful of EPS members with over 3" of rain early next
week, so the heavy rain threat will have to be watched.
As has been the case, the break in the weather looks to be short-
lived (Wednesday), but we are seeing signs for more unsettled
weather from the 4th into the 5th. Model spread during this period
remains quite large, so PoPs in the 30s and 40s from the NBM makes
sense, but we`re still a couple of days out before we can have much
confidence in saying whether or not your holiday festivities will be
impacted by weather.
Beyond this system, there is some hope that things may start to
settle down a little bit as upper ridge starts building farther
north and the upper jet begins to nudge north and weaken some, but
we`ll see if this hyper-active pattern can actually settle down.
&&
.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1045 PM CDT Fri Jun 28 2024
Mostly VFR conditions are expected the rest of tonight, though
IFR will linger at KEAU. A cold front will drop southward,
reaching west central MN around daybreak. It will bring MVFR
ceilings that will spread toward the southeast, reaching western
WI by mid morning. Northwest winds are expected to increase to
15-20 kts with gusts in the 20s by late Saturday morning.
KMSP...Timing of the increase in northwest winds is the main
item for this forecast. Have targeted 15Z for gusts around 25
knots but that may vary by an hour or so. Few other concerns.
/OUTLOOK FOR KMSP/
SUN...VFR. Wind N bcmg E 5-10 kts.
MON...VFR/MVFR, RA likely, chc -TSRA. Wind SE 10-15G25 kts.
TUE...VFR/MVFR, chc RA. Wind W 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...MPG
AVIATION...TDK
Area Forecast Discussion
National Weather Service Marquette MI
823 PM EDT Fri Jun 28 2024
.KEY MESSAGES...
- Rounds of showers are expected into Saturday and then Monday
night into Tuesday night with quiet weather following each
round.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 416 PM EDT Fri Jun 28 2024
Water vapor imagery and RAP analysis show a well-defined mid-level
low over eastern MT with wsw flow downstream into the Great Lakes.
In this wsw flow, a shortwave moving across Upper MI is responsible
for the shra that have been spreading w to e today. Most of the
rainfall has been on the light side. The clouds and shra have
resulted in a cool day with current temps mostly in the upper 50s
and lwr 60s F. The cool conditions and resulting lack of
instability, including for parcels lifted from anywhere above the
sfc, have prevented any tsra from developing. To the w, sfc low pres
is located in n central MN with a cold front extending ssw thru far
nw IA. Within 850mb theta-e ridge ahead of the front, shra/tsra are
developing from western IA into se MN.
Shra associated with aforementioned shortwave will be exiting the
eastern fcst area over the next few hrs. Attention then turns to the
convection developing to the sw. Under 850mb theta-e advection as
850mb theta-e ridge advects ne ahead of approaching cold front,
there should be additional shra/some tsra development ne thru WI
into mainly the se half of Upper MI. Additional shra/tsra, lower
coverage, will be possible along the cold front as it moves into
Upper MI during the night. With the instability that does build ne
into Upper MI limited, svr storms not expected. Temps tonight won`t
fall much from current readings. Min temps should be mostly in the
upper 50s and lwr 60s F.
&&
.LONG TERM /SATURDAY THROUGH FRIDAY/...
Issued at 510 PM EDT Fri Jun 28 2024
Starting Saturday morning, the broad trough will be centered over
northern MN with two embedded shortwaves to focus on through the day
as the trough shifts east through northern Ontario and the Upper
Great Lakes. The first shortwave on the forefront of the trough is
situated over western Lake Superior, lifting northeast toward James
Bay. The second shortwave trough over the ND/MN state line pivots
over the Upper Great Lakes into Saturday night. The associated sfc
low around 1004 mb follows the first shortwave northeast into
Quebec, dragging a cold front from eastward across the UP through
the later part of the day. PVA ahead of the passing cold front
supports isolated showers and possibly some rumbles of thunder
through the morning, but better chances for thunderstorms hold on
until the afternoon with the passing cold front. The NAM and HRRR
are the stronger solutions, kicking off storms in the east and south
central along Lake Michigan with the higher instability (SBCAPE up
to 2000-2500 J/kg). However lingering clouds from previous showers
will be a limiting factor for instability, the 6/28 12Z mean SBCAPE
only builds up to around 750-1000 J/kg in the afternoon with bulk
shear to 45-50 kts. Another limiting factor will be the timing and
location of the cold front. While an isolated strong storm bringing
some gusty winds and some small hail is possible, severe weather
seems unlikely. Forecasted highs were bumped up from the previous
forecast into the 70s, warmest south central where MOS guidance
points to highs reaching near 80. The exception to this is in the
Keweenaw where temps may struggle to reach low 60s under the
stronger northwest flow off Lake Michigan. With northwest winds
increasing through the day, a high swim risk is expected for the
Alger county beaches starting in the afternoon.
Moving into Saturday night, high pressure begins building in from
the west at the sfc, but one last shortwave digs south across the
UP. With the north-northwest upslope flow and low level moisture
noted in model soundings, this may support some light showers in
areas nearer to Lake Superior. Dry weather is expected to return
from west to east overnight as a drier airmass works its way into
the area. Stronger mixing is also expected Saturday night, resulting
in some gusts up to 20-30 mph over the east. Lows are expected in
the 40s, however with clearing and radiative cooling in the west,
some interior spots may dip into the upper 30s.
The dry period continues through Monday with high pressure overhead
and mid level ridging building in from the west. Highs on Sunday are
expected to be cooler under northerly flow, generally in the 60s. An
And with another night of mostly clear skies and radiative cooling,
lows Sunday night dip into the 40s. Mid level ridging becomes
centered over the UP on Monday with southerly flow at the lower
levels bringing temps near or just below normal with highs in the
70s.
Dry dry period ends Monday night in the west ahead of a deepening
low moving northeast off the northern Rockies. Confidence is growing
in the sfc low track, bringing it through far northern Ontario on
Tuesday, reaching Hudson Bay by around Wednesday morning as it
deepens to around 995mb. While the details with this system are
still a bit murky, general consensus is that it brings two rounds of
showers and thunderstorms. The first round touches off Monday night
with WAA and isentropic ascent in the west, later supported by a
shortwave traversing east over the Upper Great Lakes, then dries out
around mid day Tuesday. The second round is driven by the low
pressure system`s trailing cold front Tuesday afternoon into
Wednesday. After this system, model guidance really begins to
diverge. A dry period is expected to follow, but how long that
period lasts is still uncertain. Generally a wetter pattern
continues into through the first half of July.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 822 PM EDT Fri Jun 28 2024
Flight restrictions to persist for duration of TAF period as a cold
front enters Upper Michigan in the wake of an exiting shortwave.
MVFR conditions will continue for a few more hours at IWD/CMX before
deterioriating further to IFR and even LIFR at CMX tonight.
Elsewhere, upsloping southerly winds are keeping SAW at LIFR
levels already this evening and will persist into early Saturday
morning. Some improvement is possible Saturday morning after
frontal passage. In addition, an uptick in showers is expected
over the next few hours with a few rumbles of thunder,
especially at SAW. And, southerly winds will continue to gust up
to 20 kts at IWD and SAW into tonight. Wind shift to the
northwest in wake of front is progged for Saturday
morning.
&&
.MARINE...
Issued at 510 PM EDT Fri Jun 28 2024
Southeast winds up to 20-30 kts, strongest over the east, are
expected to diminish this evening from west to east with winds
falling below 20 kts by around midnight. Behind the cold front,
winds veer northwest on Saturday with increased mixing and a tighter
pressure gradient allowing for gusts up to 25-30 kts over the
eastern half of the lake. North to northeast winds Saturday night
gradually fall back below 20 kts late Saturday night as high
pressure builds in from the west. Winds are then expected to remain
below 20 kts through much of the day Monday as this high pressure
moves east over the lake. With the next passing system early next
week, southeast winds increase Monday night to 20-25 kts, veering
south to southeast on Tuesday as the low pressure system passes well
to the north of Lake Superior. Winds Tuesday night onward look to
remain below 20 kts through the remainder of the forecast period.
Stronger northwest winds behind the cold front on Saturday will
result in waves building up to 5-8 ft waves over the eastern half of
the lake Saturday night.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Beach Hazards Statement until 10 PM EDT this evening for
MIZ014.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Rolfson
LONG TERM...Jablonski
AVIATION...TDUD
MARINE...Jablonski
Area Forecast Discussion
National Weather Service Raleigh NC
753 PM EDT Fri Jun 28 2024
.SYNOPSIS...
High pressure will move off the New England coast tonight. A hotter
and more humid airmass will become established across the area this
weekend. A cold front will approach the area Sunday bringing the
next chance of storms.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 753 PM Friday...
Evening analysis shows a stalled boundary across northern sections
of SC and arcing into eastern TN. High pressure was situated off the
New England coast. The high will shift off into the north Atlantic,
resulting in a developing southerly flow toward sunrise Sat. With
the more moist flow off the southwest Atlantic, dewpoints will
likely rise overnight after mixing out earlier this afternoon.
Daytime convection along the sea-breeze brought isolated storms
across Sampson Co and the Sandhills. The convection has produced a
well pronounced outflow evident on radar, currently pushing into
Moore, Lee, and Chatham counties. As this outflow continues to track
WNW through the late evening, high-res CAMs such as the HRRR show
spotty isolated activity developing over the western/southern
Piedmont and perhaps over the Triad. Any storm activity should
weaken after midnight with loss of heating and forcing, though
cannot rule out a stray shower over the Triad near daybreak.
Overnight lows should be in the upper 60s to low/mid 70s. Guidance
is hinting at some widespread low stratus and possibly patchy fog
with the onshore flow taking shape overnight into daybreak Sat. This
should lift and dissipate by mid-morning.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
As of 415 PM Friday...
Hot, seasonably humid, with a small chance of showers/storms on the
wrn and ern flanks of cntl NC.
Cntl NC will remain tucked between a couple of sub-tropical to lower
mid-latitude mid-level highs/ridges centered over the srn Plains and
w-cntl Atlantic, respectively. Poleward of this expansive zone of
ridging, a compact mid-level cyclone now over nern MT will become an
open wave trough while pivoting across the nrn Plains and upr MS
Valley through 12Z Sat, then accelerate newd and across the Great
lakes and QC through 12Z Sun. A trailing shortwave perturbation now
over the cntl Canadian Prairies will dig sewd into the upr MS Valley
and upr Great Lakes Sat and then follow a similar path as the first
shortwave trough through Sun. In the intervening swly flow between
these shortwave perturbations and the aforementioned ridges, a
convectively-amplified mid-level trough will move across the OH
Valley and cntl Appalachians Sat and the Middle Atlantic Sat night,
the latter when weak mid-level height falls (10-20 m/12hr) will
glance the srn Middle Atlantic. Weak mid-level lapse rates of less
than 5 C/km will exist over cntl NC on Sat, with a slight increase
to between 5-5.5 C/km, amid the aforementioned weakly falling
heights, Sat night.
At the surface, the remnants of a couple of fronts that have settled
across the South Atlantic states during the past 24 hours will
retreat nwd across the Middle Atlantic, on the wrn periphery of high
pressure over the Atlantic basin. Broad sly flow will result
throughout the South and Middle Atlantic states, while a lee trough
will develop with diurnal heating over the srn Middle Atlantic and
Carolina Foothills/wrn Piedmont. Weak confluence between the
Atlantic high and lee trough will result over the Foothills and wrn
Piedmont. A sea breeze will also retreat inland and across ern and e-
cntl NC through the evening.
While both temperatures and humidity levels will be on the increase
as a result of the return to sly flow and the influence of the
ridging aloft, afternoon/mixed surface dewpoints are likely to
decrease into the upr 60s to around 70 F. Resultant heat index
values, when factoring in high temperatures mostly 92-98 F, are
likely to peak in the 100-105 F range over all but the nrn and nwrn
Piedmont, where upr 90s will be common. Those mixed dewpoints will
also result in a minimum of MLCAPE generally between 500-1000 J/KG
over cntl NC, with slightly higher dewpoints in the lwr 70s, and
MLCAPE between 1000-1500 J/KG, along and west of the Yadkin Valley
and from the the far ern Coastal Plain to the coast. A 20-30 percent
chance of showers/storms will consequently exist along the wrn/ern
flanks of cntl NC. Overall coverage and strength of convection will
be limited by the relative lack of buoyancy and forcing for ascent,
aside from low-level convergence along the sea breeze and into the
lee trough.
After a lingering small chance of showers/storms over the srn/wrn
Piedmont during the evening, it will otherwise be warm and muggy
overnight, with lows 75-80 F.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
As of 255 PM Friday...
Hot and stormy Sun/Sun night, then generally quiet and mostly dry
through the work week. Near normal temps Mon-Tue will once again
give way to intensifying heat for July 4th and into the weekend.
Sun-Sun night: Expect hot and muggy conditions with high rain
chances as a potent mid level trough deepens with a positively tilt
as it shifts through far SE Canada/St Lawrence Valley into the
Northeast states. Just ahead of this trough axis and its associated
surface front, anomalously high PWs near 2.5" will spread in
areawide, with mid level moistening and cooling resulting in an
erosion of mid level stability, as steepening lapse rates through
the column and prefrontal afternoon heating push SBCAPE to 1000-2500
J/kg, according to the latest LREF. Mid level flow and deep layer
bulk shear will remain somewhat muted much of the day, however,
peaking at just 15-25 kts, highest near the border Sun evening/night
as the stronger cyclonic flow aloft dips into our latitude with
trough axis passage. This will also result in the better upper
divergence holding off until after dark, and this lack of temporal
juxtapositioning of buoyancy and dynamic forcing for ascent could
limit our severe threat. But given the forecast SBCAPE and deep
mixing with elevated DCAPE, the threat of a few strong wet
microbursts seems realistic. Will continue with high pops, peaking
at likely at some point over the entire CWA. Sun is likely to be
another day of dangerous heat, with very warm morning temps and
highs mostly in the mid 90s, giving heat indices again around 100-
105 over most of the area. The surface front should drop slowly SE
through the area (more likely, jumping into a prefrontal trough or
convective outflow) Sun night, with some lower dewpoints expected to
start arriving into the north sections overnight. Lows in the upper
60s to mid 70s.
Mon-Fri: The front and deep moisture may still be lingering across
southern sections Mon morning, so will maintain good chance to low
likely pops there early. But as the front settles to our S and drier
air works in from the N amid briefly gusty NE winds Mon, and within
ridging both at the surface and aloft, expect a trend to no pops
late Mon, lasting through mid week as high pressure noses in from
the N. Expect temps to be near to even slightly below normal
Mon/Tue, with dewpoints in the 50s and 60s, making it feel quite
pleasant. Then, as the mid level trough extending down through the
Mid Atlantic early Mon shifts offshore and ridging builds further
from the S Plains/Lower Miss Valley into the Carolinas, with the
surface ridge pushing out over the open NW Atlantic, rising humidity
and thicknesses will bring a return to oppressive heat. Highs should
be in the low to mid 90s Wed and mid 90s to near 100 on July 4th and
Fri, as thicknesses climb to nearly 20 m above normal. With mid
level warm/stable air beneath the strong ridge aloft and limited
deep moisture flux into the area, rain chances will remain low Wed,
then will have a trend toward climo pops for Thu/Fri, just 25-35%
chance at most with those higher values focused on the extreme NW
where mountain convection could drift late each day. -GIH
&&
.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
As of 703 PM Friday...
VFR conditions will prevail to start the TAF period. However, MVFR
to IFR stratus is likely to develop at all terminals late
tonight/early Saturday morning. Otherwise, a few isolated showers
could reach KINT/KGSO this evening, but overall the forecast appears
mostly dry tonight.
Any lingering stratus should lift to VFR by late morning/early
afternoon. After which, a few isolated showers/storms could impact
KINT/KGSO tomorrow afternoon. However, coverage looks limited and
mostly confined to the mountains.
Outlook: Sub VFR conditions will be possible area wide Sun morning
with IFR stratus, followed by a good chance of mainly afternoon-
evening showers/storms Sunday. VFR conditions are expected early to
mid week next week.
&&
.CLIMATE...
Record High Temperatures:
June 30:
KFAY: 102/2012
July 4:
KGSO: 98/1970
KRDU: 101/2012
KFAY: 98/2019
Record High Minimum Temperatures:
June 28:
KRDU: 76/1952
KFAY: 78/1914
June 29:
KGSO: 74/2010
KRDU: 78/1914
KFAY: 76/1969
June 30:
KGSO: 74/1936
KRDU: 80/1936
KFAY: 79/1936
July 1:
KRDU: 75/2012
KFAY: 76/1990
July 4:
KGSO: 73/2018
KRDU: 79/1902
KFAY: 78/1913
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...CA
NEAR TERM...Kren
SHORT TERM...MWS
LONG TERM...Hartfield
AVIATION...Luchetti/CA
CLIMATE...RAH