mi discuss
Office: MQT
FXUS63 KMQT 062258
AFDMQT
Area Forecast Discussion
National Weather Service Marquette MI
658 PM EDT Mon May 6 2024
.KEY MESSAGES...
-Quiet weather through tonight.
-Complex mid-week weather pattern with rain chances increasing
on Tuesday and multiple passing low pressures keeping rain in
the forecast through the end of the week.
&&
.SHORT TERM /THROUGH TODAY/...
Issued at 142 PM EDT Mon May 6 2024
Upper air pattern consists of a 500 mb trough in the central Rockies
and a shortwave in the mid Mississippi River Valley. The trough
heads northeast and develops a closed 500 mb low that moves into the
Dakotas by 12z Tue. Weather will be quiet through tonight with very
few changes made to the going forecast.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 344 PM EDT Mon May 6 2024
The extended forecast is largely dominated by a trough currently
approaching the Northern Great Plains and its complex evolution and
influence on the surface lows moving across the CONUS through the
upcoming week, which will keep precipitation chances in the forecast
throughout the forecast period.
For Tuesday, the negatively tilted trough forms a closed off low
over the Northern Plains as the shortwave continues northeast from
Iowa to the Upper Great Lakes. This stacked low will be stalled over
the Dakotas Tuesday through Wednesday morning, but a shortwave
rotating around the base of the low aloft will be the focus for the
weather pattern heading into the midweek. This shortwave will get
jet support as it becomes coincident with a right-entrance region of
a ~125 kt 300mb, giving enough synoptic support for showers over the
UP beginning Tuesday late-morning in the west and overspreading the
UP by the end of the day. This continues a model trend of
precipitation arriving later with each major model run. With bulk
shear low (20-35 kts) and mean 12Z HREF MUCAPE of around 100mb, not
many thunderstorms are expected, but a few rumbles of thunder can't
be ruled out. With moisture advecting in and cloud cover ahead
limiting mixing potential, minimum RHs barely fall into the 30s
ahead of the approaching showers, so fire weather shouldn't be a
concern, and with a WPC Marginal Risk of Excessive Rainfall, any
minor fires that may start should be extinguished naturally.
The pressure falls associated with the shower activity Tuesday will
become a discrete surface low pressure by Wednesday morning and
depart the region by the afternoon. As it does, the original closed
low over the Dakotas will weaken from a peak strength of near 980mb
Tuesday morning to near 1000mb by midday Wednesday as it slides
southeast. As it does, it will phase with another weak lee cyclone
off the Rockies, with ensembles tracking this new low generally
around Lake Michigan and Illinois by overnight Wednesday into
Thursday. Precip will be the forecast if the northern clusters
verify, but the UP could be high and dry if a more southern solution
materializes. By Friday, anomalous ridging over coastal British
Columbia will be contrasted with anomalous troughing over the Lower
Great Lakes, putting the UP in a northwesterly flow regime. Some
deterministic and ensemble guidance suggests a clipper-type low late
in the week into the weekend, keep PoPs in the forecast, though
uncertainty is high in any specifics as the complex setup has a lot
of variables to work out first. Confidence is increasing that this
ridge will shift over the Great Lakes by the midweek of next week,
warranting the CPC to favor below normal precipitation for the
second half of May.
&&
.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 658 PM EDT Mon May 6 2024
VFR conditions continue through tonight as an occluding front
approaches the U.P. from the south, arriving Tuesday. This front
will degrade conditions at KIWD to IFR by the early afternoon and
MVFR at KCMX and KSAW late in the afternoon as rainfall moves into
the area. Some LLWS is expected over KIWD late tonight as the front
approaches. While there is a small chance (20%) for LLWS to develop
around 12z Tuesday over KCMX, given the that the stronger winds will
more than likely not reach KCMX until the late morning to early
afternoon hours (when they will be able to mix down to the surface),
LLWS isn't expected for KCMX.
&&
.MARINE...
Issued at 344 PM EDT Mon May 6 2024
With high pressure over the Upper Great Lakes, resulting stability
will keep winds mainly below 20 kts through tonight for the vast
majority of Lake Superior. The exception to this would be over the
far western portion of the lake near the Duluth Harbor where some
northeast channeling may yield some gusts up to 25 kts. An
approaching low pressure Tuesday morning will force northeasterly to
east winds to funnel over the western half of Lake Superior to 25
kts by noon Tuesday with a few gusts to 30 kts in the far west and
along the Minnesota shorelines. Winds across the east half of the
lake increase to around 20-25 kts Tuesday afternoon. A brief break
in 20+ kt winds is expected Tuesday night. Periodic chances for
winds in the 20-30 kt range dot the forecast through Thursday as
multiple weak low pressure systems pass through the Upper Great
Lakes region, but uncertainty still remains.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...07
LONG TERM...GS
AVIATION...TAP
MARINE...GS
Office: DTX
FXUS63 KDTX 062303
AFDDTX
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
703 PM EDT Mon May 6 2024
.KEY MESSAGES...
- There is a risk for isolated strong to severe storms Tuesday
evening southwest of a Midland to Port Huron line between 6 PM
and 11 PM.
- Some gusts to 60 mph are possible with potential for isolated
large hail to 1 inch in diameter.
- Cannot rule out an isolated weak tornado or two Tuesday evening.
- Mainly dry, breezy, and warmer Wednesday, then cooler again
Thursday with additional opportunities for showers and
thunderstorms.
&&
.AVIATION...
Surface high pressure moves farther into Ontario and Quebec while
maintaining control of conditions across SE Mi this evening. A
gradual transition then begins late tonight and Tuesday morning.
Surface wind remains easterly while cloud layer wind veers SW as a
warm front organizes in the Ohio valley. Clouds along and ahead of
the front begin moving into Lower Mi with low end VFR ceiling as far
north as FNT by sunrise. Low VFR holds into Tuesday afternoon with
the first weakening wave of showers/storms, then ceiling trends down
into MVFR as both showers and thunderstorms increase coverage and
intensity late in the day into Tuesday evening. The best chance of
thunderstorms is after 22Z Tuesday with very similar timing along the
terminal corridor.
For DTW/D21 Convection... Thunderstorm potential increases across
the region Tuesday afternoon. The first round of activity moves in
on a weakening trend by mid afternoon followed by a round of
stronger storms after 22Z Tuesday evening.
DTW THRESHOLD PROBABILITIES...
* Medium for ceiling 5000 feet or less Tuesday morning, high Tuesday
afternoon.
* Low for thunderstorms after 18Z Tuesday, moderate after 22Z
Tuesday evening.
&&
.PREV DISCUSSION...
Issued at 356 PM EDT Mon May 6 2024
DISCUSSION...
Ridging with central surface pressure of 1018 mb continues to anchor
the Great Lakes by flanking the northward progression of scattered
showers and storms attributed to troughing over the Ohio Valley.
Locally, expect near seasonable temperatures and dry conditions the
rest of today and tonight with prevailing easterly flow and a
persistent stream of high cirrus.
Expansive closed low occupying the western two-thirds of CONUS
(producing widespread severe convection) retrogrades from the
western Dakotas into eastern Montana Tuesday while the wave broadens
meridionally. This pushes the system's elongated warm front
northeastward into Lower Michigan with rapid moistening arriving
after 15Z. Mean 850-700 mb layer dewpoints jump from around -30C
early Tuesday morning to +5C after 18Z as the magnitude of water
vapor transport increases sharply with the transition to cyclonic
southwesterly flow. Current analysis depicts a line of convection
extending from the Mid-Mississippi Valley up to the southern
Canadian Prairies, closer to the actual surface low. CAMs highlight
a tendency for decay as storms cross Lake Michigan and interface
with a dry and stable ambient airmass. Most areas remain dry, at
least through 18Z.
Height field adjustments along the eastern periphery of the system
lend some uncertainty to the upstream evolution of convection as a
secondary shortwave emerges and shears into southern Lower. The warm
sector will fully encompass the region by 22Z, as a secondary (and
more robust response) convection response arrives with additional
storms track west to east. Given the slightly later arrival time and
flatter diurnal curve, confidence in SBCAPE has trended lower as the
main instability axis remains better centered over southwest Lower.
All hazards are in-play Tuesday evening for Southeast Michigan given
the +60 knots of 0-6 km bulk shear, southeasterly winds, and pockets
of higher instability as mid-level lapse rates cool. A secondary
surface low emerges as the triple point, and given the current
curvature reflected in forecast hodographs, isolated rotating
structures will be capable of generating some weak mesocyclones,
augmented by the frontal intersections. Cannot rule out a few
isolated weak tornados and some overachieving thunderstorm gusts.
SPC has upgraded the CWA to a Slight Risk near the MI/OH border with
a Marginal risk elsewhere (excluding The Thumb). Storms largely
depart/dissipate by 03Z with increasingly zonal flow aloft.
Warmer and more stable as dewpoints drop into the upper 40s to lower
50s Wednesday with decreasing sky opacity. Well-mixed boundary-layer
supports some decent afternoon gusts in the 25-30 mph range. The
next system crosses through Indiana and Ohio Wednesday with some
additional shower/storms possible for southern Lower. The primary
upper trough then splits again Thursday, taking aim at the Great
Lakes Thursday while the broader longwave jet pattern remains quasi-
stationary. Additional showers and storms are likely with much
cooler temperatures Thursday, related to cold frontal forcing. The
synoptic pattern unlocks Friday as an amplified ridge drops through
the Upper Midwest. Drier weather will be short lived as a trailing
PV anomaly drops into the region Saturday.
MARINE...
High pressure currently centered over Lake Huron gradually drifts
east into Ontario tonight through the first half of Tuesday
maintaining light easterly flow. Midwestern low pressure lifts a
warm front into the central Great Lakes Tuesday afternoon/evening
bringing widespread showers and thunderstorms with some strong to
severe storms possible over the southern Great Lakes. System's cold
front quickly follows overnight setting up cooler westerly flow
Wednesday, turning northeasterly Wednesday night. Cooler airmass
combined with a tighter gradient due to secondary low development
over the Ohio Valley supports a moderate uptick in wind strength
Wednesday and Thursday with gusts topping out between 15-25kts each
day. Saginaw Bay could see gusts near 30kts Thursday due to
NE winds channeling down the bay.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&
$$
AVIATION.....BT
DISCUSSION...KGK
MARINE.......KDK
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Office: APX
FXUS63 KAPX 062340
AFDAPX
Area Forecast Discussion
National Weather Service Gaylord MI
740 PM EDT Mon May 6 2024
.KEY MESSAGES...
- A few areas may see frost tonight, mainly inland.
- Rain showers/thunder Tuesday/Tuesday night...lingering
showers Wednesday especially north.
- Shower chances mainly Lower Michigan Thursday.
- More shower chances for the weekend?
.SHORT TERM /THROUGH TUESDAY/...
Issued at 334 PM EDT Mon May 6 2024
Pattern Synopsis and Forecast:
Cool night expected as high pressure slides into and to the east of
Lake Huron. Pressure gradient mildly tightens on Tuesday in advance
of the next system aloft with mildly breezy southeast winds. Large
expansive upper low digs in across the center of the country, with a
lobe of energy pinwheeling into northern Michigan from the
southwest. Thus showers, and occasional thunderstorms, will be
possible as lower pressure/sfc boundary moves into the region
on Tuesday.
Primary Forecast Concerns:
Generally light winds tonight and could be a splotch of high level
clouds try and work in tonight briefly. That being said, still
expecting cool temperatures, dipping into the 30s across some areas.
Previous fcst leaned on statistical guidance for low temps, followed
suit with a couple of spots across the interior approaching the mid
30s or so. Thus, have patchy frost in the interior, but overall
not too confident nor is this expected to be expansive or
significant with perhaps just a few brief hours in the 30s.
Cloud cover will be on the increase Tuesday as low pressure system
spins across the Dakotas with mildly breezy southeast winds
expected. Warm moist advection lifts into the region resulting in an
initial band of showers likely, with a chance for embedded/isolated
thunderstorms during the afternoon hours. Best potential for
thunderstorm development looks to be across southwest northern
lower, as the low level moisture increases and thus instability as
well (at least thru Tuesday afternoon). Convective activity will
continue into Tuesday night, read on for details.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Issued at 334 PM EDT Mon May 6 2024
Pattern Forecast: Anomalous upper low moving into the central
Rockies today (-2 to -3 sigma 500mb standardized height anomalies)
will spin slowly northward across the High Plains through
midweek...while kicking some height falls into the Great Lakes to
start the long term forecast cycle. Short wave ridging will bridge
over the top of this upper low...almost cutting it off but the end
result will be some general "bagginess" to the upper level pattern
across Michigan into Thursday and possibly lingering on Friday as
well. Upper level ridging becoming better estabilished this weekend
will send some additional short wave energy into the Great Lakes/Ohio
Valley Saturday.
Occluding low over western North Dakota will push an elongated
occluded front into Lower Michigan Tuesday afternoon along with a
short wave trough Tuesday night/Wednesday. Elongated mostly latent
PV axis left behind running east-west across southern Ontario/Lower
Michigan/Wisconsin Wednesday as upper short wave trough lingers...
general weakness in the surface pressure pattern though start to get
rising pressures into the upper Lakes Wednesday night. As the upper
trough begins to shift east Thursday looks like a couple of short
wave troughs will move through the state...one crossing Lower
Michigan/Ohio Valley...a second that is forecast to drop out of
northeast Ontario and across the forecast area Thursday night.
Another short wave trough digs southeast out of central Canada and
across the Great Lakes in the Saturday time frame.
Primary Forecast Concerns:
Rain showers/thunder Tuesday night...lingering showers Wednesday
especially north: Northward lifting occluded front will have some
dynamic support with it as a PV anomaly and the left exit region of
a 100kt jet streak across southern Lower...weakening stability as
well with some elevated CAPE. Precipitation chances may let up
along the M-55 corridor overnight...but overall highest QPF across
the Tip of the Mitt and eastern Upper (0.50" to 0.75") from 00z-12z
Wednesday. Elevated CAPE will also allow for thunderstorm chances
mainly across northern Lower/Straits region. On Wednesday deeper
moisture lingers across Upper Michigan along a 700mb trough axis...
so light rain chances will continue across eastern Upper and the
Straits region...with more sun probable the farther south you go.
Shower chances mainly Lower Michigan Thursday: Actually there is a
chance we could get some rain into northern Lower Wednesday
night...but short wave trough moving across far southern Lower/
northern portions of Indiana and Ohio with what should be
deformation band of precipitation setting up across a good portion
of Lower Michigan Thursday into Thursday night. Will have a north-
south PoP gradient across the forecast area though three days out
uncertain as to how far north precipitation chances might get.
More shower chances for the weekend?: After a respite on Friday next
short wave digging southeast into the Great Lakes should bring more
shower chances for the weekend...right now overall probabilities are
pretty low but the better chance appears to be Saturday.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 735 PM EDT Mon May 6 2024
VFR conditions under just some passing high clouds through at
least the first half of Tuesday. Expect lowering cigs and
increasing shower chances to spread in from west to east later
Tuesday, potentially bringing MVFR conditions to KTVC and KMBL.
Light winds tonight expected to become a bit gusty out of the
southeast on Tuesday.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
SHORT TERM...JLD
LONG TERM...JPB
AVIATION...MSB/JLD
Office: GRR
FXUS63 KGRR 061913
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
313 PM EDT Mon May 6 2024
.KEY MESSAGES...
- Potential for strong/severe storms Tuesday
- Wet and Cool Weather for the end of the week
&&
.DISCUSSION...
Issued at 308 PM EDT Mon May 6 2024
- Potential for strong/severe storms Tuesday
Severe storms are just developing over the Plains in response to
strong dynamics being produced by low pressure over the northern
Plains along a warm/occluded frontal band. These storms...in
weakening mode...will move east tonight and move toward Lower MI
Tuesday morning. These storms will be weakening as they move
across the cwa Tuesday morning due to drier air and limited
instability.
Once the initial showers/storms move across by late morning,
we'll likely see a lull of a couple of hours and with more storm
redevelopment during the mid afternoon. CAPE values increase
dramatically behind the frontal boundary and will be helped out
by any clearing that we see. An approaching strong short wave
that's ejected out of the Plains upper low will support convective
redevelopment. Dewpoints surge into the lower 60s behind the
front. Strong shear in the 55 kt range coupled with 1k+ j/kg
SBCAPE, 6.5-7 C/km mid level lapse rates 40kt LLJ and a 75kt mid
level jet will support organization. In this case, the strongest
dynamics will remain south of the cwa, but will be strong enough
to produce a wind and hail threat from roughly 3pm-8pm. SPC has
highlighted a Slight Risk for severe storms generally south of
I-96 with a Marginal Risk for most of the rest of the cwa. Any
lingering showers/storms should be out of the cwa by 06z
Wednesday.
- Wet and Cool Weather for the end of the week
A positive tilted mid level wave will be tracking through the Great
Lakes region later Wednesday and into Thursday. PWATs climb as this
feature tracks through topping an inch in southern parts of the CWA.
This is a good setup for period of steady rain, which will also act
to keep the temperatures down. The models do vary considerably
with the location and amounts of rain. The GFS has been steady in
showing a swath of heavier rain for Muskegon River basin, while the
ECMWF and GEM are aiming the precipitation further south and trending
further south.
Another mid level wave comes down from the Canadian Prairies on
Friday night. This wave will bring down another surge of cool air
and there could even be some lake effect rain showers with this
second wave. While qpf is projected to be light, given the
enhancement of the moisture from Lake MI, we will nudge up the POPs
for Friday night into Saturday to account for this. With 850 mb
temps struggling to top 0 deg C, the daytime temperatures are likely
to stay at least several degrees below normal for both Friday and
Saturday.
&&
.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 130 PM EDT Mon May 6 2024
The atmosphere will remain relatively dry into the start of
Tuesday so VFR conditions are predicted. An overall east to
southeast flow will prevail as an area of high pressure retreats
northeastward into southern Ontario and into Quebec. A band of
showers and embedded thunderstorms will likely be moving into the
southwest TAF sites of KMKG, KAZO and KBTL by noon so we featured
conditions trending downward at that time. Thunderstorms were not
included as there is some uncertainty of whether there will still
be thunderstorms as the band of precipitation moves in near the
end of the forecast period.
&&
.MARINE...
Issued at 308 PM EDT Mon May 6 2024
Southeast wind gusts will increase to around 20 knots tonight
which may touch on advisory criteria for a few hours Tuesday
morning, but given the offshore flow and the short duration, we'll
hold off on a headline for now.
Thunderstorms are possible Tuesday morning and again Tuesday
afternoon, which the afternoon storms being potentially strong to
severe.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...MJS/04
AVIATION...MJS
MARINE...04
