SPC MD 1719

MD 1719 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PORTIONS OF EASTERN KANSAS INTO WESTERN MISSOURI

MD 1719 Image


Mesoscale Discussion 1719
NWS Storm Prediction Center Norman OK
1053 AM CDT Sun Sep 27 2020

Areas affected...Portions of Eastern Kansas into Western Missouri

Concerning...Severe potential...Watch unlikely 

Valid 271553Z - 271730Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated strong thunderstorms with the potential for large
hail are possible late this morning and into the afternoon. The
relatively isolated nature of the stronger storm coverage may
preclude a Severe Thunderstorm Watch.

DISCUSSION...A strong thunderstorm has recently developed along/near
a southward-moving cold front across portions of Lyon County,
Kansas, with a 1.25-1.5" hail report recently near Admire. RAP
mesoanalysis suggests 500-1000 J/kg of MLCAPE in this area with
effective bulk shear of 40-50 knots. While there may be a tendency
for the cold front to undercut some updrafts, at least a few
updrafts should persist long enough to produce severe hail,
especially given the strong shear through the hail growth zone.
Thunderstorms should continue to move across eastern Kansas and into
Western Missouri, as depicted by several 12Z HREF members. 

While convective coverage may remain too limited for a watch
issuance, trends will continue to be monitored and a Slight Risk
will be added in this area with the 1630Z Convective Outlook to
cover this threat.

..Elliott/Grams.. 09/27/2020

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

ATTN...WFO...LSX...SGF...EAX...TOP...ICT...

LAT...LON   39189581 39519474 39339345 38819277 38359296 38059373
            37879465 38019558 38539631 39189581 

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SPC MD 1654

MD 1654 CONCERNING SEVERE THUNDERSTORM WATCH 478…479… FOR SOUTHERN MO…FAR SOUTHERN IL AND FAR WESTERN KY

MD 1654 Image


Mesoscale Discussion 1654
NWS Storm Prediction Center Norman OK
1243 PM CDT Mon Aug 31 2020

Areas affected...southern MO...far southern IL and far western KY

Concerning...Severe Thunderstorm Watch 478...479...

Valid 311743Z - 311915Z

The severe weather threat for Severe Thunderstorm Watch 478, 479
continues.

SUMMARY...Strong, locally damaging gusts will continue to be
possible across parts of central into southeast MO through
mid-afternoon.

DISCUSSION...A line of convection is currently tracking southeast at
around 40-45 kt across central MO into southern MO. If this storm
motion continues, convection could approach the edges of WW 478 and
479 in southeast MO around 19z. Recent CAPPI trends have shown some
weakening of cores over the last hour, and IR satellite indicates
modest warming of cloud tops. It is likely that convection has
reached peaked intensity. 0-6km shear is rather weak downstream,
though the airmass remains moderately unstable with MLCAPE values as
high as 2000 J/kg noted in 17z mesoanalysis. Furthermore,
approximately 50 kt of rear inflow has been measured by regional
radar. As a result, some severe potential could develop with
southeastward extent and move outside of the current severe
thunderstorm watches. The need for a downstream watch will be
evaluated.

Further west, convection has struggled to intensify as it develops
south/southeast into southwest MO. This is likely due to some
remaining inhibition from earlier morning convection/outflow.
Portions of WW 478 could be cancelled early if convective trends
continue to weaken across the region.

..Leitman.. 08/31/2020

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

ATTN...WFO...PAH...MEG...LSX...LZK...SGF...

LAT...LON   36479283 36529393 36729430 37079448 37409447 37639427
            37929224 38069129 37999019 37758891 37658869 37368841
            36968834 36598856 36478911 36358977 36529123 36479283 

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SPC MD 1650

MD 1650 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR PARTS OF NORTHEASTERN EAST CENTRAL KANSAS INTO NORTHWEST AND WEST CENTRAL MISSOURI

MD 1650 Image


Mesoscale Discussion 1650
NWS Storm Prediction Center Norman OK
0456 AM CDT Mon Aug 31 2020

Areas affected...Parts of northeastern east  central Kansas into
northwest and west central Missouri

Concerning...Severe potential...Watch possible 

Valid 310956Z - 311200Z

Probability of Watch Issuance...40 percent

SUMMARY...It is not yet certain that a severe weather watch will be
needed, but thunderstorms developing across the region could pose
increasing potential for marginally severe hail and strong surface
gusts through daybreak.

DISCUSSION...Forcing for ascent associated with a modest, veering
(to an increasingly westerly component) pre-frontal low-level jet
appears to be contributing to ongoing increasing convective
development in a corridor across northeastern and east central
Kansas.  Although the Rapid Refresh suggests that this jet may begin
to weaken shortly, lift appears to be increasingly focused within a
weakness in inhibition associated with the warm elevated mixed-layer
air, where the eastward advection of seasonably high moisture
content is contributing to most unstable CAPE of 2000-3000 J/kg.  

Given this destabilization, thunderstorm activity seems likely to
continue to develop and intensify through daybreak.  Although the
region will remain between the belts of stronger westerlies aloft,
veering profiles with height along this corridor may be contributing
to deep-layer shear at least marginally sufficient for organized
strong/severe convection.

Furthermore, as a southeastward advancing cold front begins to
overspread the region by 11-13Z, enhancement of lift, where it
intersects this band of elevated convection, may contribute to an
intensifying, upscale growing cluster of storms.  This could be
accompanied by increasing risk for strong surface gusts, in addition
to occasional marginally severe hail.

..Kerr/Edwards.. 08/31/2020

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

ATTN...WFO...EAX...OAX...TOP...

LAT...LON   40339513 39539380 38649374 38089457 38389541 39519609
            40039625 40339513 

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SPC MD 1648

MD 1648 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR SOUTHERN NEBRASKA INTO NORTHERN KANSAS

MD 1648 Image


Mesoscale Discussion 1648
NWS Storm Prediction Center Norman OK
1142 PM CDT Sun Aug 30 2020

Areas affected...southern Nebraska into northern Kansas

Concerning...Severe potential...Watch possible 

Valid 310442Z - 310645Z

Probability of Watch Issuance...40 percent

SUMMARY...Storms may eventually form along a surging cold front
across Nebraska and into Kansas, with wind and hail potential.

DISCUSSION...Surface analysis shows a strong cold front moving
across central NE and into northwest KS. While the air mass is
currently capped, it remains unstable with MUCAPE to 2000 J/kg. 

Given the strength of the low-level convergence, storms are expected
to form along the front. These may briefly be supercells before
getting undercut as deep-layer shear is favorable along with lapse
rates aloft, and it is not clear whether an MCS will be able to form
and keep pace with the surging front. Trends will continued to be
monitored for a potential hail and wind threat developing over the
next few hours.

..Jewell/Guyer.. 08/31/2020

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

ATTN...WFO...OAX...TOP...ICT...GID...DDC...GLD...

LAT...LON   41819769 41329695 40519659 39649702 39049765 38939854
            39099902 39579976 40239993 40719929 41819769 

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SPC MD 1642

MD 1642 CONCERNING SEVERE THUNDERSTORM WATCH 472… FOR SOUTHEAST OKLAHOMA…SOUTHWEST ARKANSAS…NORTHEAST TEXAS…NORTHERN LOUISIANA

MD 1642 Image


Mesoscale Discussion 1642
NWS Storm Prediction Center Norman OK
1133 PM CDT Sat Aug 29 2020

Areas affected...southeast Oklahoma...southwest Arkansas...northeast
Texas...northern Louisiana

Concerning...Severe Thunderstorm Watch 472...

Valid 300433Z - 300600Z

The severe weather threat for Severe Thunderstorm Watch 472
continues.

SUMMARY...An MCS will gradually shift south across the Arklatex
area, with a continued threat of gusty winds and heavy rain.

DISCUSSION...An MCS with impressive IR presentation (cloud top
temperatures to -80 C) is approaching the Red River, overturning a
very moist and unstable air mass. Southwest winds at 850 mb will
favor continued inflow into this system as it propagates slowly
southward. Periodic strong to severe downdrafts remain possible. A
slight westward growth/expansion cannot be ruled out as pockets of
warmer air remain surrounding the Metroplex. However, additional
watches may not be necessary.

..Jewell.. 08/30/2020

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

ATTN...WFO...LZK...SHV...TSA...FWD...OUN...

LAT...LON   34069636 34269575 34539460 34409281 33729230 33469235
            32829329 32909462 33109602 33369625 33729644 34069636 

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SPC MD 1624

MD 1624 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PARTS OF CENTRAL KANSAS

MD 1624 Image


Mesoscale Discussion 1624
NWS Storm Prediction Center Norman OK
0220 AM CDT Sat Aug 29 2020

Areas affected...Parts of central Kansas

Concerning...Severe potential...Watch unlikely 

Valid 290720Z - 290915Z

Probability of Watch Issuance...20 percent

SUMMARY...Thunderstorm activity may continue to be accompanied by
strong, gusty winds through daybreak.

DISCUSSION...Ongoing vigorous cluster of storms near/north of Dodge
City appears supported by a weak mid-level perturbation emerging
from the Southwest, and associated lower/mid-tropospheric warm
advection along the northern periphery of a remnant plume of warm
elevated mixed-layer air.  

This activity appears rooted above a substantive surface cold front,
where the pressure gradient is contributing to 25-35 kt
northeasterly flow around 850 mb, northeast through southwest of the
Dodge City area. This may continue to slowly shift southeastward
through daybreak.

Despite a layer of modestly steep mid-level lapse rates, CAPE for
elevated moist parcels may only be on the order of 1000-1500 J/kg,
but modest shear in the convective layer has contributed to
organization of storms.  This includes a compact area of stronger
storms now passing just to the north of Dodge City, near an evolving
MCV, with a rear inflow jet evident to its south.  This includes
speeds in excess of 50 kt as low as around 500 feet, some of which
may have mixed down and contribute to the 50 kt gust recorded at
Garden City.

MRMS CAPPI data does indicate weakening of this convection may be
underway.  However, new thunderstorm development appears underway
closer to the front, near Medicine Lodge, and the larger area of
vigorous thunderstorm development may persist and gradually spread
across much of central Kansas through daybreak.  While locally
strong surface gusts may also continue, any additional severe gusts
probably will remain rather localized and sparse in coverage.

..Kerr/Edwards.. 08/29/2020

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

ATTN...WFO...TOP...ICT...GID...DDC...GLD...

LAT...LON   38910011 39239901 39119734 38539608 37699644 37269718
            37099853 37359978 37910054 38910011 

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SPC MD 1587

MD 1587 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR IDAHO INTO SOUTHWEST MONTANA

MD 1587 Image


Mesoscale Discussion 1587
NWS Storm Prediction Center Norman OK
0804 PM CDT Wed Aug 26 2020

Areas affected...Idaho into southwest Montana

Concerning...Severe potential...Watch unlikely 

Valid 270104Z - 270300Z

Probability of Watch Issuance...5 percent

SUMMARY...Isolated strong to severe storms will remain possible
through sunset. Strong downburst winds remain the primary threat
associated with these storms. A watch remains unlikely.

DISCUSSION...Radar and satellite trends over the past 2 hours across
ID and southwest MT have shown a slight uptick in convective
coverage and intensity with several storms showing moderate to
strong cloud top cooling. The environment over this region remains
supportive of organized convection with upwards of 1000 J/kg MUCAPE
and 45 knot effective bulk shear. Although there is some inhibition
in place, orographic ascent has thus far been able to overcome this
limitation. Furthermore, increasing (albeit weak) ascent ahead of an
approaching shortwave trough to the west should help maintain
sufficient ascent for convection through the evening hours.
Low-level lapse rates across the region continue to support a strong
wind potential, and instances of severe hail can not be ruled out
given adequate instability, shear, and mid-level lapse rates. This
activity should gradually diminish after sunset this evening, and
the threat will remain too isolated to warrant a watch.

..Moore/Guyer.. 08/27/2020

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

ATTN...WFO...BYZ...RIW...TFX...SLC...PIH...MSO...BOI...LKN...

LAT...LON   42031713 43831701 45721458 46241347 45991129 45551010
            44461086 42941269 41941403 42031713 

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SPC MD 1585

MD 1585 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR SOUTHERN SOUTH DAKOTA

MD 1585 Image


Mesoscale Discussion 1585
NWS Storm Prediction Center Norman OK
0721 PM CDT Wed Aug 26 2020

Areas affected...Southern South Dakota

Concerning...Severe potential...Watch unlikely 

Valid 270021Z - 270215Z

Probability of Watch Issuance...5 percent

SUMMARY...Ongoing strong to severe storms will continue to pose an
isolated hail and wind threat through sunset. A watch is not
expected.

DISCUSSION...Radar trends over the past couple of hours have shown
additional convective development along the southward propagating
outflow of the initial cluster of supercells that developed in
central SD. Recent IR imagery shows rapid cloud top cooling and an
uptick in lightning activity associated with this newer convection,
indicating that the environment remains unstable with little
inhibition. Recent RAP analyses support this idea with little MLCIN
and nearly 2000 J/kg MLCAPE ahead of the outflow across southern SD.
Effective bulk shear at 40-45 knots also remains favorable for
organized convection. 

Deep layer flow roughly oriented along the outflow boundary may
increase the probability of storm interactions, which could limit
the duration and coverage of the severe threat moving forward.
However, given this environment initially discrete storms should
remain capable a hail and wind threat through sunset when diurnal
cooling will begin to increase inhibition and limit the potential
for sustained mature convection.

..Moore/Guyer.. 08/27/2020

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

ATTN...WFO...ABR...LBF...UNR...

LAT...LON   43440275 43860216 44220089 44190016 43539979 43060003
            42990069 42950155 42970249 43440275 

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SPC MD 1584

MD 1584 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR NORTHERN WISCONSIN AND THE WESTERN UPPER PENINSULA OF MICHIGAN

MD 1584 Image


Mesoscale Discussion 1584
NWS Storm Prediction Center Norman OK
0619 PM CDT Wed Aug 26 2020

Areas affected...Northern Wisconsin and the western Upper Peninsula
of Michigan

Concerning...Severe potential...Watch unlikely 

Valid 262319Z - 270045Z

Probability of Watch Issuance...5 percent

SUMMARY...Periodic intensification within a line of storms is
possible over the next couple of hours. Isolated hail and perhaps
damaging wind are possible, but a watch is not expected.

DISCUSSION...Radar imagery over the past hour from KDLH has shown a
growing line of thunderstorms along the southwestern shores of Lake
Superior/northern WI. A few intense cores have been noted in MRMS
vertically integrated ice data as well as cooling top temperatures
in IR imagery, but these cores have largely failed to maintain
intensity for more than 10 minutes or so. This is largely due to
increasing inhibition with eastward extent that is so far limiting
the severe potential of this line. However, RAP forecast soundings
suggest that gradual cooling in the 850-700 mb layer, associated
with the approach of a weak shortwave trough, may help reduce
inhibition over the next couple of hours. Around 1500 J/kg MLCAPE
and 35-40 knots of effective bulk shear should remain in place
across northern WI/western U.P of MI, and although the potential for
severe hail and wind is low, this environment could support brief
intensifications along the line that may be capable of severe hail
and damaging winds. Due to the low probability of sustained severe
convection, a watch is not expected.

..Moore/Guyer.. 08/26/2020

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

ATTN...WFO...MQT...GRB...DLH...

LAT...LON   46479199 46829162 46959052 46918928 46808865 46438824
            46198873 46068965 46139093 46219182 46479199 

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SPC MD 1517

MD 1517 CONCERNING SEVERE THUNDERSTORM WATCH 445… FOR PORTIONS OF NORTH-CENTRAL AND NORTHEAST KANSAS

MD 1517 Image


Mesoscale Discussion 1517
NWS Storm Prediction Center Norman OK
0931 PM CDT Sun Aug 16 2020

Areas affected...Portions of north-central and Northeast Kansas

Concerning...Severe Thunderstorm Watch 445...

Valid 170231Z - 170330Z

The severe weather threat for Severe Thunderstorm Watch 445
continues.

SUMMARY...A line of storms in north-central and northeast Kansas is
expected to slowly weaken over the next few hours.

DISCUSSION...The line of storm in Riley and Clay counties has shown
warming cloud tops over the past hour with radar echo tops also
decreasing. Expect this trend to continue as the storms move into an
increasingly capped and stable environment. Storms may continue with
severe or near severe winds for the next hour, but likely won't
persist at severe limits much beyond that and the watch will likely
be able to be cancelled before the 05Z expiration time.

..Bentley.. 08/17/2020

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

ATTN...WFO...TOP...ICT...

LAT...LON   39519770 39639726 39679665 39289630 38359620 37789642
            37779708 37879751 38779779 39519770 

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