Hail and Damaging Winds in Michigan, July 10, 2023

Area Forecast Discussion
National Weather Service Marquette MI
328 PM EDT Mon Jul 10 2023

.SHORT TERM...(Through early afternoon)
Issued at 1114 AM EDT MON JUL 10 2023

Morning showers associated with the initial push of a cold front
moving into the region have exited Upper Michigan. This supported
some isolated shower activity over mostly the south and east this
morning, with a few embedded thunderstorms observed as well.

Following this, low level clouds pressed eastward just ahead of the
analyzed cold front and worked to establish a north-south
temperature gradient over the forecast area as the front took on a
more west-east orientation. Current placement of the front is that
it extends eastward from near Lake o' Lakes across the central.
North of the boundary, temps have been largely steady in the low 70s
or upper 60s but south of the boundary, temps have warmed into the
mid 70s with dewpoints in the low-mid 60s. Along and south of the
boundary, current mesoanalysis paints a corridor of increasing
instability and should be the main focus for afternoon/evening
convection late today.

.LONG TERM...(Late Afternoon through Monday)
Issued at 328 PM EDT MON JUL 10 2023

An active and seasonably cool pattern is expected to prevail
throughout the long-term as an upper level low parks across the
Manitoba-Ontario-Hudson Bay region. Shortwaves rotating around the
closed low about every other day result in frequent rain chances and
near to above normal precip through the extended period. The most
energetic/amplified shortwave pivots southeast across the area late
this afternoon into early tonight. A noticeably cooler and drier
air mass moves in behind tonights cold front with clearing skies
leading to some fog potential, especially where it rains this
evening. The next chance for more widespread showers/storms
appears to be Friday into Saturday , but there could be a few
isolated showers during the aftn/evening Wednesday and Thursday
too.

Confidence is high that thunderstorms will develop in the vicinity
of a cold front later this afternoon and evening as an intense PV
maxima digs southeast toward the UP. Surface observations and the
17Z RAP mesoanalysis indicates that frontal boundary is currently
positioned near the line from Land o' Lakes, WI east to Trenary, MI
north-northeast to Wawa, Ontario. A lake-breeze enhanced cold front
showed up on radar around 1630Z and surged south across Alger County
where it intersected a shower that developed over northern WI late
this morning. RAP model soundings indicate in this area show ~1000
J/kg MLCAPE and effective shear of 35-40 knots that is sufficient
for organized updrafts, but so far updrafts continue to struggled
reach the modeled equilibrium level (though the storm passing south
of Iron Mountain at 19Z seems to be tapping into better CAPE). The
majority of available shear is below 3km with uniform westerly flow
from there up to the equilibrium level suggesting more surface-
based, pre-frontal storms have the best severe potential. Thus, this
threat is mainly confined to the triangle Iron Mountain to Escanaba
to Marinette.

Looking ahead through this evening, HREF guidance shows thunderstorm
probabilities increasing from ~30% at 21z to ~90% at 01Z as the 850
mb LLJ ramps up to near or above 30 knots. Additional convergence at
the nose of this feature is likely to result in more widespread
thunderstorm development. Model soundings by 02Z show a stable
boundary layer with weak to moderate elevated instability rooted
near 850 mb and cloud layer bulk shear near or below 20 knots.
Overall, this suggests poorly organized storms along and north of
the cool front and given the cooler environment there could be some
small hail potential with the strongest storms. The other aspect to
monitor is related to heavy rainfall potential as a narrow axis of
fairly impressive f-gen forcing intensifies with the LLJ this
evening. Event-total probability matched means seem to have
decreased a bit, but still indicate a narrow axis where training
thunderstorms are possible this evening. The latest guidance
suggests this axis will extend roughly between Iron Mountain and
Munising.

Rapid post-frontal drying/clearing results in clearing skies from NW
to SE tonight that when combined with earlier rainfall could allow
for patchy fog formation. While the 12z 3km NAM is likely too
aggressive with nocturnal cooling, it deserves an honorable mention
for dipping lows into the mid-30s across the typical cool spots of
the interior west. The next shortwave moves into the area on
Wednesday, but dry low levels suggests it will struggle to squeeze
and precip out of the increasing cloud cover. If rain occurs on Wed,
the best chance appears to be near the WI state line. Somewhat more
moisture in place for Thursday could allow for diurnal shower
activity, but a better chance for rain arrives on Friday as another
cold front pushes across the UP. A reinforcing cool front could
wring out of lighter showers on Saturday before the next dry air
mass moves in for Sunday/Monday.
&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 120 PM EDT MON JUL 10 2023

A cold front will press through the region this afternoon and
evening, focusing shower and thunderstorm activity along and ahead
of the boundary. Showers and storms could produce heavy rain that
may reduce visibilities and ceilings. KSAW will most likely be
impacted, but KIWD can't be ruled out. Outside of this, expecting
clearings skies overnight and a return to VFR conditions.
&&

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 328 PM EDT MON JUL 10 2023

A cold front pushed across the lake today with generally light and
variable winds late this afternoon. Northwesterly winds overspread
the lake by Tuesday morning but will remain light and below 20 knots
through next weekend. Showers and thunderstorms will be likely
especially across the southeast half of the Lake from late this
afternoon through this evening.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&

SHORT TERM...JTP
LONG TERM...EK
AVIATION...JTP
MARINE...EK

Hazardous Weather Outlook
National Weather Service Marquette MI
342 PM EDT Mon Jul 10 2023

MIZ001>007-009>014-084-085-111945-
Keweenaw-Ontonagon-Northern Houghton-Baraga-Marquette-Alger-Luce-
Gogebic-Iron-Dickinson-Menominee-Delta-Southern Schoolcraft-
Southern Houghton-Northern Schoolcraft-
342 PM EDT Mon Jul 10 2023 /242 PM CDT Mon Jul 10 2023/

This Hazardous Weather Outlook is for portions of central Upper
Michigan and western Upper Michigan.

.DAY ONE...Tonight

Thunderstorms are expected tonight, diminishing from west to east
late. Some storms may be strong with small hail and heavy rainfall.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter reports of hail, wind damage, and heavy rain would be
appreciated today.

LSZ162-240>251-263>267-111945-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-Saxon Harbor WI to Black River MI-
Black River to Ontonagon MI-
Ontonagon to Upper Entrance of Portage Canal MI-
Upper Entrance of Portage Canal to Eagle River MI-
Eagle River to Manitou Island MI-
Manitou Island to Point Isabelle MI-
Point Isabelle to Lower Entrance of Portage Canal MI-
Lower Entrance of Portage Canal To Huron Islands MI Including
Keweenaw and Huron Bays-Huron Islands to Marquette MI-
Marquette to Munising MI-Munising to Grand Marais MI-
Grand Marais to Whitefish Point MI-
Lake Superior from Saxon Harbor WI to Upper Entrance to Portage
Canal MI 5NM off shore to the US/Canadian border including Isle
Royale National Park-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
Lake Superior East of a line from Manitou Island to Marquette MI
and West of a line from Grand Marais MI to the US/Canadian Border
Beyond 5NM from shore-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
342 PM EDT Mon Jul 10 2023 /242 PM CDT Mon Jul 10 2023/

This Hazardous Weather Outlook is for portions of Central Lake
Superior...Eastern Lake Superior and Western Lake Superior.

.DAY ONE...Tonight

Thunderstorms are expected tonight, mainly over the southeastern
half of the lake dissipating late. Some storms may be strong with
small hail and heavy downpours.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

The need for weather spotter reports is not anticipated at this
time.

LMZ221-248-250-111945-
Green Bay North of line from Cedar River MI to Rock Island
Passage-Seul Choix Point to Point Detour MI-
5NM East of a line from Fairport MI to Rock Island Passage-
342 PM EDT Mon Jul 10 2023

This Hazardous Weather Outlook is for portions of Northern Lake
Michigan.

.DAY ONE...Tonight

Thunderstorms are expected tonight. Some storms may be strong with
small hail and heavy rainfall.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

The need for weather spotter reports is not anticipated at this
time.

Jablonski/EK

Preliminary Local Storm Report
National Weather Service Marquette MI
239 PM EDT Mon Jul 10 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1240 AM     Non-Tstm Wnd Gst 54 ENE Keweenaw Point   47.59N 86.58W
07/10/2023  M45 MPH          LSZ266             MI   Buoy

            Mesonet station 45004 East Superior Buoy.

&&

DJ

Special Weather Statement
National Weather Service Marquette MI
208 PM CDT Mon Jul 10 2023

MIZ011-012-101945-
Menominee MI-Dickinson MI-
208 PM CDT Mon Jul 10 2023

...A strong thunderstorm will impact portions of south central
Dickinson and northwestern Menominee Counties through 245 PM CDT...

At 208 PM CDT, Doppler radar was tracking a strong thunderstorm near
Norway, or 11 miles southeast of Iron Mountain, moving east at 40
mph.

HAZARD...Winds in excess of 30 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
  Hermansville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4560 8778 4565 8783 4567 8782 4568 8778
      4572 8784 4575 8788 4577 8797 4578 8797
      4582 8784 4578 8752 4558 8757
TIME...MOT...LOC 1908Z 278DEG 33KT 4571 8788

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...30 MPH

jp

Special Weather Statement
National Weather Service Marquette MI
419 PM CDT Mon Jul 10 2023

MIZ010-102145-
Iron MI-
419 PM CDT Mon Jul 10 2023

...A strong thunderstorm will impact portions of northeastern Iron
County through 445 PM CDT...

At 419 PM CDT, Doppler radar was tracking a strong thunderstorm near
Amasa, or 9 miles north of Iron River, moving east at 50 mph.

HAZARD...Winds in excess of 30 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Amasa, Way Dam and Mineral Hills.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4630 8871 4638 8812 4616 8811 4613 8812
      4613 8813 4612 8868
TIME...MOT...LOC 2119Z 263DEG 43KT 4622 8858

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...30 MPH

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