SPC – No watches are valid as of Sun Jul 25 03:02:02 UTC 2021

Source: US National Oceanic and Atmospheric Administration

Current Convective Watches (View What is a Watch? clip)Updated:  Sun Jul 25 03:15:06 UTC 2021 No watches are currently valid

Archived Convective WatchesTo view convective weather watches for a previous day, type in the date you wish to retrieve (e.g. 20040529 for May 29, 2004). Data available since January 1, 2004.

SPC – No MDs are in effect as of Sun Jul 25 03:02:02 UTC 2021

Source: US National Oceanic and Atmospheric Administration

Current Mesoscale DiscussionsUpdated:  Sun Jul 25 03:15:03 UTC 2021 No Mesoscale Discussions are currently in effect.

Notice:  The responsibility for Heavy Rain Mesoscale Discussions has been transferred to the Weather Prediction Center (WPC) on April 9, 2013. Click here for the Service Change Notice.
Archived Mesoscale DiscussionsTo view mesoscale discussions for a previous day, type in the date you wish to retrieve (e.g. 20040529 for May 29, 2004). Data available since January 1, 2004.

SPC Jul 25, 2021 0100 UTC Day 1 Convective Outlook

Source: US National Oceanic and Atmospheric Administration

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Jul 25, 2021 0100 UTC Day 1 Convective Outlook
Updated: Sun Jul 25 00:40:07 UTC 2021 (Print Version |   |  )
Probabilistic to Categorical Outlook Conversion Table

 Forecast Discussion

SPC AC 250040

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0740 PM CDT Sat Jul 24 2021

Valid 250100Z – 251200Z

…THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF
NORTHERN ILLINOIS INTO SOUTHEAST MICHIGAN…

…SUMMARY…
A few severe thunderstorms with wind damage, isolated large hail,
and perhaps a tornado remain possible from portions of northern
Illinois into southeast Lower Michigan/northwest Ohio this evening.

…Midwest/Lower Great Lakes…

Substantial mid-level drying is spreading south across the upper
Great Lakes region as northwesterly flow deepens/strengthens across
WI/MI with upper trough passage. Deep convection has organized ahead
of this feature along a corridor from southeast lower MI-northern
IN-northern IL-IA/MO border. While a few supercells are embedded
with this activity, a broken squall line has matured and is
advancing southeast at roughly 25kt. This activity will exit watches
#390/391 soon and may not weaken for several hours as temperatures
remain in the 80s with modest instability immediately downstream.
For these reasons will extend the SLGT risk another 30-40 miles
south of its current position to allow for more organized/severe to
continue through 03-04z.

..Darrow.. 07/25/2021

CLICK TO GET WUUS01 PTSDY1 PRODUCT

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SPC Severe Thunderstorm Watch 391

Source: US National Oceanic and Atmospheric Administration

Note:  The expiration time in the watch graphic is amended if the watch is replaced, cancelled or extended.Note: Click for Watch Status Reports.
SEL1

URGENT – IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 391
NWS Storm Prediction Center Norman OK
330 PM CDT Sat Jul 24 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of
Northern Illinois
Northern Indiana
Southwest Lower Michigan
Lake Michigan

* Effective this Saturday afternoon and evening from 330 PM until
1000 PM CDT.

* Primary threats include…
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1.5 inches in diameter possible

SUMMARY…Thunderstorms are slowly intensifying along a line from
north of Chicago into northwest Illinois. These storms will spread
southward through the afternoon, posing a risk of locally damaging
wind gusts and hail.

The severe thunderstorm watch area is approximately along and 45
statute miles north and south of a line from 50 miles west southwest
of Marseilles IL to 35 miles southeast of Kalamazoo MI. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU1).

PRECAUTIONARY/PREPAREDNESS ACTIONS…

REMEMBER…A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

OTHER WATCH INFORMATION…CONTINUE…WW 390…

AVIATION…A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
30025.

…Hart

SEL1

URGENT – IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 391
NWS Storm Prediction Center Norman OK
330 PM CDT Sat Jul 24 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of
Northern Illinois
Northern Indiana
Southwest Lower Michigan
Lake Michigan

* Effective this Saturday afternoon and evening from 330 PM until
1000 PM CDT.

* Primary threats include…
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1.5 inches in diameter possible

SUMMARY…Thunderstorms are slowly intensifying along a line from
north of Chicago into northwest Illinois. These storms will spread
southward through the afternoon, posing a risk of locally damaging
wind gusts and hail.

The severe thunderstorm watch area is approximately along and 45
statute miles north and south of a line from 50 miles west southwest
of Marseilles IL to 35 miles southeast of Kalamazoo MI. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU1).

PRECAUTIONARY/PREPAREDNESS ACTIONS…

REMEMBER…A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

OTHER WATCH INFORMATION…CONTINUE…WW 390…

AVIATION…A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
30025.

…Hart

Note: The Aviation Watch (SAW) product is an approximation to the watch area. The actual watch is depicted by the shaded areas.
SAW1
WW 391 SEVERE TSTM IL IN MI LM 242030Z – 250300Z
AXIS..45 STATUTE MILES NORTH AND SOUTH OF LINE..
50WSW MMO/MARSEILLES IL/ – 35SE AZO/KALAMAZOO MI/
..AVIATION COORDS.. 40NM N/S /4SSE BDF – 54N FWA/
HAIL SURFACE AND ALOFT..1.5 INCHES. WIND GUSTS..60 KNOTS.
MAX TOPS TO 500. MEAN STORM MOTION VECTOR 30025.

LAT…LON 41748957 42528507 41228507 40438957

THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU1.

Watch 391 Status Report Message has not been issued yet.

Note:  Click for Complete Product Text.TornadoesProbability of 2 or more tornadoes

Low (10%)

Probability of 1 or more strong (EF2-EF5) tornadoes

Low ( 65 knots

Low (20%)

HailProbability of 10 or more severe hail events

Low (20%)

Probability of 1 or more hailstones > 2 inches

Low (10%)

Combined Severe Hail/WindProbability of 6 or more combined severe hail/wind events

Mod (60%)

For each watch, probabilities for particular events inside the watch (listed above in each table) are determined by the issuing forecaster. The “Low” category contains probability values ranging from less than 2% to 20% (EF2-EF5 tornadoes), less than 5% to 20% (all other probabilities), “Moderate” from 30% to 60%, and “High” from 70% to greater than 95%. High values are bolded and lighter in color to provide awareness of an increased threat for a particular event.

SPC Severe Thunderstorm Watch 390

Source: US National Oceanic and Atmospheric Administration

Note:  The expiration time in the watch graphic is amended if the watch is replaced, cancelled or extended.Note: Click for Watch Status Reports.
SEL0

URGENT – IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 390
NWS Storm Prediction Center Norman OK
315 PM EDT Sat Jul 24 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of
Central and Southern Lower Michigan
Lake Huron

* Effective this Saturday afternoon and evening from 315 PM until
1000 PM EDT.

* Primary threats include…
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1 inch in diameter possible
A tornado or two possible

SUMMARY…Multiple lines and clusters of thunderstorms will move
across the watch area this afternoon and early evening, posing a
risk of locally damaging wind gusts and isolated hail. A tornado or
two cannot be ruled out.

The severe thunderstorm watch area is approximately along and 65
statute miles north and south of a line from 40 miles east of Oscoda
MI to 35 miles west of Grand Rapids MI. For a complete depiction of
the watch see the associated watch outline update (WOUS64 KWNS
WOU0).

PRECAUTIONARY/PREPAREDNESS ACTIONS…

REMEMBER…A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

AVIATION…A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few
cumulonimbi with maximum tops to 500. Mean storm motion vector
28030.

…Hart

SEL0

URGENT – IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 390
NWS Storm Prediction Center Norman OK
315 PM EDT Sat Jul 24 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of
Central and Southern Lower Michigan
Lake Huron

* Effective this Saturday afternoon and evening from 315 PM until
1000 PM EDT.

* Primary threats include…
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1 inch in diameter possible
A tornado or two possible

SUMMARY…Multiple lines and clusters of thunderstorms will move
across the watch area this afternoon and early evening, posing a
risk of locally damaging wind gusts and isolated hail. A tornado or
two cannot be ruled out.

The severe thunderstorm watch area is approximately along and 65
statute miles north and south of a line from 40 miles east of Oscoda
MI to 35 miles west of Grand Rapids MI. For a complete depiction of
the watch see the associated watch outline update (WOUS64 KWNS
WOU0).

PRECAUTIONARY/PREPAREDNESS ACTIONS…

REMEMBER…A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

AVIATION…A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few
cumulonimbi with maximum tops to 500. Mean storm motion vector
28030.

…Hart

Note: The Aviation Watch (SAW) product is an approximation to the watch area. The actual watch is depicted by the shaded areas.
SAW0
WW 390 SEVERE TSTM MI LH 241915Z – 250200Z
AXIS..65 STATUTE MILES NORTH AND SOUTH OF LINE..
40E OSC/OSCODA MI/ – 35W GRR/GRAND RAPIDS MI/
..AVIATION COORDS.. 55NM N/S /34E ASP – 19SSW MKG/
HAIL SURFACE AND ALOFT..1 INCH. WIND GUSTS..60 KNOTS.
MAX TOPS TO 500. MEAN STORM MOTION VECTOR 28030.

LAT…LON 43518259 41948621 43828621 45398259

THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU0.

Watch 390 Status Report Message has not been issued yet.

Note:  Click for Complete Product Text.TornadoesProbability of 2 or more tornadoes

Low (20%)

Probability of 1 or more strong (EF2-EF5) tornadoes

Low (5%)

WindProbability of 10 or more severe wind events

Mod (40%)

Probability of 1 or more wind events > 65 knots

Low (20%)

HailProbability of 10 or more severe hail events

Low (20%)

Probability of 1 or more hailstones > 2 inches

Low (10%)

Combined Severe Hail/WindProbability of 6 or more combined severe hail/wind events

Mod (60%)

For each watch, probabilities for particular events inside the watch (listed above in each table) are determined by the issuing forecaster. The “Low” category contains probability values ranging from less than 2% to 20% (EF2-EF5 tornadoes), less than 5% to 20% (all other probabilities), “Moderate” from 30% to 60%, and “High” from 70% to greater than 95%. High values are bolded and lighter in color to provide awareness of an increased threat for a particular event.

SPC Severe Thunderstorm Watch 390 Status Reports

Source: US National Oceanic and Atmospheric Administration

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Watch 390 Status Reports

Watch 390 Status Message has not been issued yet.

Top/Watch Issuance Text for Watch 390/All Current Watches/Forecast Products/Home

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SPC MD 1340

Source: US National Oceanic and Atmospheric Administration

Mesoscale Discussion 1340
NWS Storm Prediction Center Norman OK
0121 PM CDT Sat Jul 24 2021

Areas affected…Much of central and southern lower Michigan into
adjacent portions of northwestern Ohio and northern Indiana

Concerning…Severe potential…Watch possible

Valid 241821Z – 242015Z

Probability of Watch Issuance…60 percent

SUMMARY…At least scattered thunderstorm development still appears
probable, now mostly likely around 4-6 PM EDT, with the potential to
organize into clusters capable of producing damaging wind gusts.
Trends continue to be monitored for the possibility of a severe
weather watch.

DISCUSSION…Initial attempts at intensifying thunderstorm
development across/east of the Houghton Lake vicinity appear to be
waning, perhaps due to weakening of the trailing mid-level cyclonic
vorticity center. However, the boundary layer across much of
central and southern lower Michigan remains moist, modestly unstable
and weakly inhibited, to the south of the effective warm frontal
zone, and ahead of conglomerate convective outflow trailing across
northern Lake Michigan through southern Wisconsin.

Although the mid-level trough axis is in the process of shifting
across and northeast of the Lake Huron/Georgian Bay vicinity,
moderately strong (40+ kt around 500 mb) west-northwesterly
mid-level flow will maintain strong deep-layer shear across the
region into this evening. Beneath this regime, it still appears
that continuing daytime heating will support the initiation of at
least scattered thunderstorm activity, perhaps focused on the lake
breeze advancing inland off Lake Michigan. Aided by the shear, this
activity may tend to grow upscale, with organizing clusters posing a
risk for potentially damaging wind gusts.

..Kerr/Hart.. 07/24/2021

…Please see www.spc.noaa.gov for graphic product…

ATTN…WFO…DTX…APX…IWX…GRR…LOT…

LAT…LON 41798656 42398606 43928602 44548520 43718306 42148299
41198652 41448715 41798656

SPC Jul 24, 2021 1630 UTC Day 1 Convective Outlook

Source: US National Oceanic and Atmospheric Administration

 For best viewing experience, please enable browser JavaScript support.

Jul 24, 2021 1630 UTC Day 1 Convective Outlook
Updated: Sat Jul 24 16:24:57 UTC 2021 (Print Version |   |  )
Probabilistic to Categorical Outlook Conversion Table

 Forecast Discussion

SPC AC 241624

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1124 AM CDT Sat Jul 24 2021

Valid 241630Z – 251200Z

…THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING FROM NORTHERN ILLINOIS INTO LOWER MICHIGAN…

…SUMMARY…
Severe thunderstorms with wind damage, isolated large hail, and a
tornado or two are expected from northern Illinois into Lower
Michigan this afternoon and evening.

…Lower MI…
A well-defined shortwave trough over WI/Upper Mi will track rapidly
eastward today across Lower MI. A moist and unstable air mass is in
place over this region, along with relatively strong vertical shear.
Thunderstorms (including a supercell or two) are expected to develop
by mid-afternoon and track across the region, posing a risk of
damaging wind gusts and isolated tornadoes. Please refer to MCD
#1339 for further details.

…IL/IN…
By mid-late afternoon, strong instability is expected to develop
along the trailing cold front from southwest Lower MI into northern
IL/IN. Scattered thunderstorms are expected to form along this
axis, although models vary significantly regarding coverage and
intensity. Those storms that do form will pose a risk of damaging
wind gusts through the early evening.

…AZ/NV…
Similar to yesterday, scattered afternoon thunderstorms will affect
much of northern AZ and southern NV. A moist boundary layer coupled
with strong heating through early afternoon will help to yield
MLCAPE values around 1500 J/kg. Low-level shear is weak, but 25
knot mid-level winds will help organize westward-moving cold pools
and result in the potential for gusty winds in some areas, along
with hail in the higher elevations.

..Hart/Lyons.. 07/24/2021

CLICK TO GET WUUS01 PTSDY1 PRODUCT

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SPC Jul 24, 2021 1730 UTC Day 2 Convective Outlook

Source: US National Oceanic and Atmospheric Administration

SPC AC 241728

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1228 PM CDT Sat Jul 24 2021

Valid 251200Z – 261200Z

…THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
OHIO VALLEY INTO THE NORTHEAST…AND ALSO ACROSS PARTS OF SOUTH
DAKOTA…

…SUMMARY…
Thunderstorms with isolated wind-damage potential are possible
across parts of the Ohio valley and Northeast, and also across parts
of South Dakota, Sunday afternoon and evening.

…Ohio Valley into the Northeast…
A belt of 30-40 kt west-northwesterly midlevel flow will largely
remain in place from the northern Plains into the Northeast on
Sunday, along the southern periphery of a deep mid/upper-level
trough covering much of eastern Canada. An embedded midlevel
shortwave trough is forecast to move across New England during the
morning and early afternoon, with another shortwave trough glancing
northern New England Sunday night, but otherwise large-scale ascent
may remain weak from the OH Valley into the Northeast through much
of the period. As a result, coverage of robust afternoon
thunderstorm development remains uncertain. However, a few strong
storms will be possible along/ahead of a weak surface boundary
sagging into the region. Effective shear of 20-30 kt will support
the potential for weakly organized cells/clusters, with isolated
damaging wind possible where low-level lapse rates can steepen
during the afternoon.

…South Dakota…
Isolated thunderstorms may develop across portions of South Dakota
by late afternoon, as MLCINH is removed by strong surface
heating/mixing. Potential areas for initiation include a weak
surface trough across western SD, and a weak surface boundary near
the ND/SD border. Despite rather limited low-level moisture, MLCAPE
is expected to rise into the 500-1000 J/kg range as temperatures
increase to near or above 100F in some locations. Modest
west-northwesterly midlevel flow will support effective shear of
25-35 kt, sufficient for at least transient storm organization. A
very warm and deeply-mixed boundary layer will support an isolated
severe-wind risk with the strongest storms and outflows.

…Southwest…
As a midlevel trough continues to drift westward across Arizona,
moderate instability and modestly enhanced midlevel flow/deep-layer
shear may again support a few organized storms across portions of
the Southwest. The areal extent of the more favorable environment is
expected to be smaller than previous days, so no probabilities have
been included at this time. However, a few strong cells/clusters
cannot be ruled out, especially from northwest AZ/southwest UT into
southern NV and perhaps southeast CA.

..Dean.. 07/24/2021

CLICK TO GET WUUS02 PTSDY2 PRODUCT

NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z

Researchers Discover Undocumented Crayfish Species in Kansas

Source: US National Invasive Species Information Center

PRATT – Widespread sampling for invasive crayfish had never occurred in Kansas lakes – that is, until the Kansas Department of Wildlife and Parks (KDWP) recently funded a university project focused on the freshwater crustacean. KDWP’s Aquatic Nuisance Species Program and Ecological Services section funded the project with the overarching goal of establishing sampling protocols that could then be used for long-term monitoring of both native and invasive crayfish in Kansas. To the surprise of staff and researchers, the need for such protocols would be validated almost as quickly as the research project began.

During capturing efforts at McPherson State Fishing Lake – one of several small waterbodies slated to be inspected in the state – university researchers collected multiple Rusty Crayfish. Rusty Crayfish have not previously been documented in the wild in Kansas, making this official “discovery” the first of its kind. Rusty Crayfish captured at McPherson consisted of both males and females of varying ages, indicating a reproducing population is established in the lake. Unfortunately, this isn’t the type of species staff and researchers would hope to find, as the Rusty Crayfish is an invasive species known for the considerable ecological damage it can cause in waterbodies.

This large, aggressive crayfish is not only known to attack the feet of unsuspecting humans and animals standing in freshwater, it outcompetes both native fish and crayfish species for forage – forage that also acts as important cover for select prey species.

“The most likely cause of the Rusty Crayfish making its way into Kansas is through its use as fishing bait,” said KDWP Aquatic Nuisance Species coordinator, Chris Steffen. “This species is a prime example of the importance of always draining water from your boat, livewell, and bilge before leaving a waterbody, and of never moving bait from one waterbody to another. You just never know what could be hitchhiking a ride.”

Staff and researchers working on the crayfish project will continue to experiment with multiple capture methods and techniques on a small number of waterbodies around the state. Once an effective and efficient sampling protocol has been identified, staff will continue the sampling efforts across a large number of lakes across the state.

Anglers, boaters and watersport enthusiasts are encouraged to keep their eyes open for this invasive species, which can be identified by its trademark large, black-tipped claws and rust-colored spots on its upper shell. If one is discovered, freeze it in a sealed plastic bag, note the date and location of capture, and contact KDWP’s Emporia Research and Survey Office at (620) 342-0658.

For information on other aquatic nuisance species in Kansas, visit ksoutdoors.com/Fishing/Aquatic-Nuisance-Species.

###