SPC MD 1516

MD 1516 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR NORTH-CENTRAL KANSAS

MD 1516 Image


Mesoscale Discussion 1516
NWS Storm Prediction Center Norman OK
0723 PM CDT Sun Aug 16 2020

Areas affected...North-central Kansas

Concerning...Severe potential...Watch possible 

Valid 170023Z - 170200Z

Probability of Watch Issuance...40 percent

SUMMARY...A new severe thunderstorm watch is possible as a cluster
of storms drifts south out of Nebraska

DISCUSSION...Storms have quickly congealed into a cluster in
southeast Nebraska and have started to accelerate
south-southwestward. Expect this storm activity to follow the
instability gradient which would take the cluster into north-central
and eventually central Kansas. There is some uncertainty how far
south this cluster will maintain severe thresholds this evening and
into the overnight hours. The air mass south of this activity
remains favorable for severe convection with MLCAPE around 3000 to
4000 J/kg per SPC mesoanalysis and effective shear around 40 kts per
KUEX VWP which should maintain this cluster for at least a few more
hours. If the cluster becomes well organized, it may persist south
of watch 443 and 444 and a new watch may be needed. In addition, new
convection has recently formed from Jewell to Graham counties and
has shown quite robust updraft growth. Therefore, if these storms
maintain this intensity as they move southeast, a new watch may need
to be issued sooner. These trends will be monitored over the next
hour.

..Bentley/Guyer.. 08/17/2020

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

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

LAT...LON   39360014 39919889 40169799 40209725 40119689 39759669
            39199682 38759724 38519778 38529808 38449885 38529943
            38660012 39360014 

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SPC MD 1514

MD 1514 CONCERNING SEVERE THUNDERSTORM WATCH 443… FOR SOUTHEAST NEBRASKA

MD 1514 Image


Mesoscale Discussion 1514
NWS Storm Prediction Center Norman OK
0631 PM CDT Sun Aug 16 2020

Areas affected...Southeast Nebraska

Concerning...Severe Thunderstorm Watch 443...

Valid 162331Z - 170100Z

The severe weather threat for Severe Thunderstorm Watch 443
continues.

SUMMARY...The threat for large hail and damaging winds continues
across southeast Nebraska.

DISCUSSION...Several supercells along and ahead of a southward
moving cold front should continue through the evening. The airmass
ahead of this activity remains quire favorable with MLCAPE around
3000 to 4000 J/kg and effective shear around 40 kts per UEX VWP. The
exception is across far southeast Nebraska where drier air is
present and thus instability is more meager. Therefore, expect this
easternmost convection to continue to weaken as it moves into an
increasingly hostile airmass. Farther west where supercells are
expected to persist, both large hail and damaging winds remain
possible. The combination of strong shear and well organized
supercells combined with mid-level lapse rates around 7.5 C/km per
SPC mesoanalysis will also support a continued threat for some 2+
inch hail. 

Storms are expected to congeal and interact with several outflow
boundaries in the next 1 to 2 hours. This may eventually lead to a
cluster of storms that could pose a greater severe wind threat for a
few hours as storms approach the Kansas border.

..Bentley.. 08/16/2020

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

ATTN...WFO...OAX...TOP...GID...

LAT...LON   40739929 41199838 41459739 41219615 40799573 40219601
            39939759 39869841 40209914 40739929 

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SPC MD 1495

MD 1495 CONCERNING SEVERE THUNDERSTORM WATCH 440… FOR CENTRAL KANSAS

MD 1495 Image


Mesoscale Discussion 1495
NWS Storm Prediction Center Norman OK
0901 PM CDT Fri Aug 14 2020

Areas affected...Central Kansas

Concerning...Severe Thunderstorm Watch 440...

Valid 150201Z - 150300Z

The severe weather threat for Severe Thunderstorm Watch 440
continues.

SUMMARY...A large hail and damaging wind threat will persist across
central Kansas for a few more hours.

DISCUSSION...The current cluster of supercells in north central
Kansas has shown no sign of weakening to this point and has produced
2.5 inch hail as recently as 120Z. Temperatures remain in the upper
80s with dewpoints in the low to mid 70s ahead of this activity. SPC
mesoanalysis shows these storms moving into a reservoir of 4500 J/kg
MLCAPE with no inhibition suggesting these storms may persist for a
few more hours as they move south. Additional evidence for this is
the new storm which has formed in southern Osborne county (ahead of
the cold front) in the last 45 minutes showing that surface based
buoyancy is still present. Averaging the 00Z RAOB from DDC and TOP
suggests effective shear around 30 to 35 kts and mid-level lapse
rates of 8.8 C/km. This will continue to support a threat for large
hail and perhaps some damaging winds. Without any upper-level
support and no low-level jet, expect these storms to weaken slowly
as the boundary layer cools over the next several hours. A small
severe thunderstorm watch was issued downstream of this activity
given the expectation for it to persist for a few more hours.

..Bentley/Guyer.. 08/15/2020

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

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

LAT...LON   39369891 39569847 39689805 39629750 39099710 38389732
            38159797 38129873 38499892 39369891 

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SPC MD 1493

MD 1493 CONCERNING SEVERE THUNDERSTORM WATCH 438… FOR NORTHERN KANSAS AND SOUTHERN NEBRASKA

MD 1493 Image


Mesoscale Discussion 1493
NWS Storm Prediction Center Norman OK
0617 PM CDT Fri Aug 14 2020

Areas affected...Northern Kansas and southern Nebraska

Concerning...Severe Thunderstorm Watch 438...

Valid 142317Z - 150045Z

The severe weather threat for Severe Thunderstorm Watch 438
continues.

SUMMARY...Expect storms to continue to build southwestward along the
front this evening.

DISCUSSION...A large supercell has continued southward across
southeast Nebraska this evening with several reports of 1.25 inch
hail and a few brief tornado reports. Expect additional development
to continue on the western flank of the ongoing activity along the
cold front through the evening. The brief tornadoes are likely a
result of vorticity stretching along the cold front boundary where
extreme instability (4000-5000 J/kg MLCAPE) is resulting in extreme
low-level parcel accelerations. A threat for an additional brief
tornado or two remains possible for the next 2 hours before the
threat diminishes as the boundary layer cools. A lack of stronger
upper-level forcing should allow storm activity to gradually weaken
after sunset with most of the severe weather threat coming to an end
by 04-05Z.

..Bentley.. 08/14/2020

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

ATTN...WFO...OAX...TOP...ICT...GID...

LAT...LON   40199907 40679812 40849759 40989668 40579623 39939628
            39509688 39249781 39079852 39169913 39629938 40199907 

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SPC MD 1475

MD 1475 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR SOUTHEAST KS…EASTERN OK

MD 1475 Image


Mesoscale Discussion 1475
NWS Storm Prediction Center Norman OK
0435 AM CDT Thu Aug 13 2020

Areas affected...Southeast KS...Eastern OK

Concerning...Severe potential...Watch unlikely 

Valid 130935Z - 131130Z

Probability of Watch Issuance...20 percent

SUMMARY...Increased potential for damaging wind gusts exists across
east-central OK. Large hail remains the primary threat across
northeast OK and southeast KS.

DISCUSSION...Strong to occasionally severe thunderstorms have
persisted over the last several hours from southeast KS into
northeast/east-central OK. Development of these storms is being
supported by a moderately strong low-level jet extending from the
southern TX Panhandle northeastward into north-central OK. These
storms were initially elevated above a warm layer between 850 and
700 mb. However, continued storm development over the same location
has likely led to a cooling and moistening of this layer, lowering
storm bases and contributing to an increase potential for strong
wind gusts. Occurrence of this scenario is evidenced by recent
surface observations, with the Tulsa Mesonet site measuring a 64 mph
gust around 0825Z and Bixby Mesonet site measuring a 61 mph gust
around 0855Z. Given these trends and recent increase in
southeasterly storm motion, an increased probability of strong to
severe wind gusts will exist downstream across east-central OK for
at least the next hour or so. Environmental conditions remain
supportive of strong to severe thunderstorms upstream across
northeast OK into southeast KS. Large hail is the primary threat
with these storms, although some damaging wind gust potential also
exist. Additionally, the heavy, training precipitation may lead to
flash flooding, as addressed in Mesoscale Precipitation Discussion
623 from WPC.

..Mosier/Hart.. 08/13/2020

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

ATTN...WFO...TSA...TOP...ICT...OUN...

LAT...LON   35489629 36489673 37609688 38149674 38299635 37629543
            35319450 34649542 35489629 

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SPC MD 1474

MD 1474 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR SOUTH-CENTRAL/SOUTHEAST KS…NORTHEAST OK

MD 1474 Image


Mesoscale Discussion 1474
NWS Storm Prediction Center Norman OK
1247 AM CDT Thu Aug 13 2020

Areas affected...South-Central/Southeast KS...Northeast OK

Concerning...Severe potential...Watch unlikely 

Valid 130547Z - 130745Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated severe hail possible across
south-central/southeast KS and adjacent northeast OK for the next
few hours.

DISCUSSION...Thunderstorms have developed over the past 1-2 hours
across south-central KS and adjacent northeast OK. This development
was supported by a strengthening low-level jet and the resulting
warm-air advection across the warm and moist air mass in place
across the southern Plains. Thus far, storms have remained along the
northeastern periphery of the stronger northwesterly flow aloft, in
an area of generally modest vertical shear. Even so, the combination
of modest vertical shear and moderate/strong buoyancy will still
result in updrafts occasionally strong and organized enough to
produce large hail. Warm low to mid-level temperatures (generally
from 850 to 700 mb) will likely keep these storms elevated for at
least the next several hours, minimizing the potential for damaging
wind gusts.

..Mosier/Hart.. 08/13/2020

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

ATTN...WFO...TSA...TOP...ICT...OUN...

LAT...LON   37569740 38179784 38719728 38689626 36479531 35819580
            35649669 36879712 37569740 

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SPC MD 1460

MD 1460 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR FAR NORTHERN TEXAS PANHANDLE INTO SOUTHERN KANSAS…NORTHERN OKLAHOMA…SOUTHWESTERN MISSOURI…AND EXTREME NORTHWEST ARKANSAS

MD 1460 Image


Mesoscale Discussion 1460
NWS Storm Prediction Center Norman OK
0450 PM CDT Mon Aug 10 2020

Areas affected...Far northern Texas Panhandle into southern
Kansas...northern Oklahoma...southwestern Missouri...and extreme
northwest Arkansas

Concerning...Severe potential...Watch possible 

Valid 102150Z - 102315Z

Probability of Watch Issuance...40 percent

SUMMARY...Vigorous convective development and intensification is
underway across parts of the southern Plains. Damaging gusts are the
primary threat, with some severe hail possible as well. Convective
trends will be monitored for the need of one or more WWs to address
the increasing severe threat.

DISCUSSION...Rapid pulse cellular and multicellular development has
been underway over the past couple of hours, situated within an
instability axis ahead of a southward sagging cold front. Steep
lapse rates (7.5-9 C/km) throughout a deep layer of the troposphere
are currently supporting up to 3000 J/kg MLCAPE. While tropospheric
flow is weak overall, noticeable veering in the sfc-700 mb layer is
promoting some deep-layer shear for marginal storm organization.
Upscale growth of a few convective clusters via cold pool mergers
are possible, where more concentrated damaging wind threats may
ensue. As such, convective trends will continue to be monitored for
upscale organization and the need of potential WW issuance over the
next couple of hours.

..Squitieri/Thompson.. 08/10/2020

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

ATTN...WFO...LZK...SGF...TSA...TOP...ICT...OUN...DDC...AMA...

LAT...LON   36410246 37600140 38340098 38079591 37719440 36989241
            36269206 35549243 35659363 36009600 36219955 36410246 

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SPC MD 1457

MD 1457 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR MUCH OF MISSOURI…FAR EASTERN KANSAS…AND SOUTHERN ILLINOIS

MD 1457 Image


Mesoscale Discussion 1457
NWS Storm Prediction Center Norman OK
0238 PM CDT Mon Aug 10 2020

Areas affected...Much of Missouri...far Eastern Kansas...and
Southern Illinois

Concerning...Severe potential...Watch possible 

Valid 101938Z - 102145Z

Probability of Watch Issuance...60 percent

SUMMARY...A few multi-cell clusters should develop this afternoon,
with damaging winds/hail possible. Trends will be monitored for
possible watch issuance across parts of the region.

DISCUSSION...Regional satellite/radar trends show a variety of
convective development processes occurring across the region. 

  1) An early morning band of severe convection continues to move
northeastward into northeast Missouri, where outflow from the
ongoing MCS has largely stabilized the atmosphere. These storms may
end up merging with the MCS across this area into central Illinois,
where MLCAPE of 3000-4000 J/kg resides. 

  2) A persistent band of elevated convection from northwest
Missouri into southeast Kansas is beginning to show signs of rooting
into the boundary layer. This uptick in intensity is also evident in
visible satellite. This trend appears to pose the greatest
short-term threat.

  3) Boundary layer cumulus is developing across south-central
Missouri amid strong diabatic heating (temperatures in the low 90s
F) and rich low-level moisture (dew point temperatures in the low to
mid 70s F). This process has yielded MLCAPE of 2500-3000 J/kg.

Given the widespread destabilization that has occurred, and the
convective trends noted, convection should become more widespread
throughout the afternoon. Despite ample instability, winds aloft are
generally weak, with only about 20 kt of effective bulk shear
present, with perhaps some enhancement near the MCS in central
Illinois. Thus storms should form into a few mutli-cell clusters,
posing a threat damaging winds and large hail. Convective trends
will be monitored for potential watch issuance this afternoon.

..Karstens/Grams.. 08/10/2020

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

ATTN...WFO...PAH...ILX...LSX...SGF...EAX...TSA...TOP...ICT...

LAT...LON   36799475 37959571 40179296 40118766 36938868 36609234
            36799475 

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SPC Center Public Severe Weather Outlook (PWO)

Public Severe Weather Outlook

PWO Image

PUBLIC SEVERE WEATHER OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1118 AM CDT MON AUG 10 2020

...Severe thunderstorms expected over parts of the Midwest this
afternoon and evening...

* LOCATIONS...
  Central and Eastern Iowa
  Northern Illinois
  Southern Wisconsin
  Northwestern Indiana
  Southwestern Lower Michigan

* HAZARDS...
  Widespread damaging winds, some hurricane force
  A couple of tornadoes
  Isolated large hail

* SUMMARY...
  A derecho producing widespread damaging winds, some of which
  should be intense, is expected to persist and expand east from
  Iowa into parts of the Midwest through this evening.

Preparedness actions...

Review your severe weather safety procedures for the possibility
of dangerous weather today. Stay tuned to NOAA Weather Radio,
weather.gov, or other media for watches and warnings. A watch
means that conditions are favorable for severe thunderstorms
over the next several hours. If a severe thunderstorm warning is
issued for your area, move to a place of safety, ideally in an 
interior room on the lowest floor of a sturdy building.

&&

..Gleason.. 08/10/2020

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SPC MD 1438

MD 1438 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR SOUTHEASTERN KANSAS INTO SOUTHERN MISSOURI

MD 1438 Image


Mesoscale Discussion 1438
NWS Storm Prediction Center Norman OK
0534 PM CDT Sun Aug 09 2020

Areas affected...Southeastern Kansas into southern Missouri

Concerning...Severe potential...Watch unlikely 

Valid 092234Z - 100030Z

Probability of Watch Issuance...5 percent

SUMMARY...A few damaging wind gusts and perhaps a couple severe
hailstones may accompany the stronger storms. A WW issuance is not
expected given the isolated, brief nature of the threat.

DISCUSSION...A southward surging outflow boundary, originating from
an earlier MCS/associated cold pool, has recently resulted in the
initiation of isolated, mainly multicellular convection across
portions of southeast KS into southern MO. Temperatures in the 90s,
with low to mid 70s dewpoints, characterize the airmass ahead of the
outflow boundary, resulting in 3000+ J/kg MLCAPE. Weak deep-layer
flow and resultant vertical shear suggest that even the more intense
storms will struggle to organize and sustain themselves in the
ambient environment. However, latest mesoanalysis depicts locally
stronger low-level shear in close proximity to the boundary, which
may encourage brief instances of updraft rotation. As such, brief
periods of damaging gusts and perhaps a couple severe hail stones
may exist. Nonetheless, the severe threat is expected to remain
isolated and short-lived overall, with the latest HRRR runs not
depicting much in the way of further convective development. As
such, a WW issuance is not expected.

..Squitieri/Dial.. 08/09/2020

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

ATTN...WFO...PAH...LSX...LZK...SGF...EAX...TSA...TOP...ICT...

LAT...LON   38469692 38159571 37759340 37719171 38039048 37789034
            37639030 37379031 37019045 36699068 36399103 36159193
            36199260 36629367 37019511 37559645 38469692 

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