SPC Center Public Severe Weather Outlook (PWO)

Public Severe Weather Outlook

PWO Image

PUBLIC SEVERE WEATHER OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0218 AM CDT SUN APR 19 2020

...Severe thunderstorms expected over parts of the southeast US
later today and tonight...

* LOCATIONS...
  Central and southern Alabama
  Central and southern Georgia
  Northwestern Florida Panhandle
  Central and southern Mississippi
  Central and northern Louisiana
  East Texas

* HAZARDS...
  Widespread damaging winds, some hurricane force
  Several tornadoes, a few intense
  Scattered large hail, some baseball size

* SUMMARY...
  An outbreak of tornadoes and severe thunderstorms is expected
  today from parts of the lower Mississippi Valley across much of
  the the Southeast. In addition to tornadoes, many of the storms
  will have very large hail and wind damage. The severe threat
  will be greatest from north-central Louisiana eastward to
  southern and central Mississippi, southern and central Alabama
  into south-central Georgia. Additional severe storms with a
  threat for tornadoes, wind damage and hail will be possible in
  parts of east Texas this morning and in the Carolinas tonight.

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

Read more

from SPC Convective Outlooks https://bit.ly/1Mw5lDA

SPC MD 390

MD 0390 CONCERNING HEAVY SNOW FOR PORTIONS OF SOUTHEAST NEBRASKA…SOUTHWEST IOWA…AND FAR NORTHWEST MISSOURI

MD 0390 Image


Mesoscale Discussion 0390
NWS Storm Prediction Center Norman OK
0129 PM CDT Thu Apr 16 2020

Areas affected...Portions of Southeast Nebraska... Southwest
Iowa...and far Northwest Missouri

Concerning...Heavy snow 

Valid 161829Z - 162230Z

SUMMARY...Heavy snow with snow rates of 1 to 2 inches per hour
expected to expand eastward this afternoon and evening.

DISCUSSION...Heavy snow has begun to develop in a mesoscale band
located along a sloping warm front from far northern Kansas into
southern Nebraska. Surface obs in the Grand Island and Hastings
vicinity recently reported heavy snow. Afternoon satellite imagery
shows IR cloud tops continuing to cool as previous elevated
convection over north Kansas expands to the north. This is supported
by area RAP and NAM soundings which show ascent associated with 700
and 850 mb frontogenesis and weak elevated instability with MUCAPE
between 50 and 100 J/KG. HREF guidance indicates a favorable zone
for snow rates of 1 to 2 inches per hour developing over southeast
Nebraska and across the Missouri Valley during the next few hours.
Eastward expansion of the heavier snow rates is likely as the upper
trough over the Rockies ejects onto the plains and dendritic growth
layer depth increases later this afternoon.

..Lyons/Grams.. 04/16/2020

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

ATTN...WFO...DMX...EAX...OAX...GID...LBF...

LAT...LON   40319930 41139989 41689877 41729731 41599479 40819415
            40359460 40159594 40149759 40319930 

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SPC MD 387

MD 0387 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR CENTRAL/EASTERN FLORIDA PANHANDLE

MD 0387 Image


Mesoscale Discussion 0387
NWS Storm Prediction Center Norman OK
0348 PM CDT Tue Apr 14 2020

Areas affected...Central/Eastern Florida Panhandle

Concerning...Severe potential...Watch unlikely 

Valid 142048Z - 142245Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated strong to severe wind gusts or a brief
tornado/waterspout will be possible with storms moving near and
onshore this afternoon and evening. A weather watch is not
anticipated.

DISCUSSION...Echo tops of 35-40kft from the KTLH radar suggest an
increase in intensity with a couple of the offshore cells south of
the Florida Big Bend region. Weak upper level lift from a passing
shortwave trough has overspread this region. Partial clearing across
the Florida Panhandle and a seasonably moist boundary layer with
dewpoints in the low to mid 70s are supporting MLCAPE of 1000-1500
J/kg. This unstable airmass is overlain by effective shear of 40 kts
sampled from regional VWPS. Mid-level mesocyclones have been
observed with a few of the cells and environmental parameters
support continued strengthening and maintenance of updrafts through
this afternoon and evening. A few of the stronger storms will be
capable of damaging wind gusts or a brief tornado as they move
onshore and across parts of the central/eastern Florida Panhandle.
Instability wanes farther to the north across southern Georgia.
Limited certainty on the coverage and intensity of the severe threat
suggests a weather watch is unlikely.

..Lyons/Grams.. 04/14/2020

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

ATTN...WFO...JAX...TAE...

LAT...LON   29968573 30098574 30378530 30468479 30528442 30568371
            30478308 29768276 29548343 29958402 29658466 29518515
            29738556 29968573 

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SPC MD 355

MD 0355 CONCERNING TORNADO WATCH 106… FOR PORTIONS OF CENTRAL MS

MD 0355 Image


Mesoscale Discussion 0355
NWS Storm Prediction Center Norman OK
0140 PM CDT Sun Apr 12 2020

Areas affected...Portions of central MS

Concerning...Tornado Watch 106...

Valid 121840Z - 122015Z

The severe weather threat for Tornado Watch 106 continues.

SUMMARY...Severe potential should be maximized across parts of
central MS this afternoon. This continues to include the possibility
of strong tornadoes.

DISCUSSION...A small cluster moving into central MS may be
transitioning to a supercell, with echo tops approaching 50,000 ft.
Yet another TDS has recently been observed with this convection in
Yazoo County, MS. The airmass downstream of this activity remains
quite favorable for organized, severe convection. The 18Z sounding
from JAN shows a very strong and veered wind profile in the low
levels in association with a 60-70+ kt low-level jet. The low-level
inversion observed around 850 mb is expected to continue eroding as
ascent associated with both the low-level jet and an approaching
mid-level trough overspread this region.

A meso-low has also been observed from 18Z surface analysis over far
southeastern AR and northwestern MS. Surface winds are locally
backed to east-southeasterly along a marine warm front extending
eastward from this low across parts of northern/central MS. A
relatively confined corridor of greater severe potential is apparent
this afternoon across parts of central MS, generally to the east of
the ongoing cluster/supercell and south of the northward-advancing
warm front. Across this area, a sufficiently unstable airmass
coupled with very strong low and mid-level shear will continue to
support the potential for tornadoes with any storms that can form/be
sustained. Some of these tornadoes could be strong given the ample
low-level shear. A threat for damaging winds and perhaps some large
hail also exists.

..Gleason.. 04/12/2020

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

ATTN...WFO...JAN...

LAT...LON   32909063 33349014 33498949 33428848 32818848 32408855
            32258931 31999098 32909063 

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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
0121 AM CDT SUN APR 12 2020

...Severe thunderstorms expected over parts of the southeast US
today through tonight...

* LOCATIONS...
  Mississippi
  Alabama
  Northern Louisiana
  Southern and eastern Arkansas
  Western Georgia
  Western and middle Tennessee
  East Texas
  The Florida Panhandle
  The Missouri Bootheel
  Western Kentucky

* HAZARDS...
  Several tornadoes, a few intense
  Widespread damaging winds
  Scattered large hail, some baseball size

* SUMMARY...
  An outbreak of severe thunderstorms is likely today into
  tonight, with the greatest threat expected from Louisiana
  through much of the Southeast and Tennessee Valley. Strong
  tornadoes will be most probable during the day from northeast
  Louisiana across central and northern portions of Mississippi
  and Alabama. Later in the afternoon and evening, another round
  of severe storms with widespread damaging winds, large hail and
  tornadoes is expected across Arkansas into western Tennessee and
  western Kentucky by early tonight. The severe-weather threat
  will persist into tonight and early Monday across Georgia and
  the western Carolinas.

Read more

from SPC Convective Outlooks https://bit.ly/1Mw5lDA

SPC MD 340

MD 0340 CONCERNING SEVERE THUNDERSTORM WATCH 101… FOR CENTRAL/EASTERN KANSAS AND NORTHWESTERN MISSOURI

MD 0340 Image


Mesoscale Discussion 0340
NWS Storm Prediction Center Norman OK
0803 PM CDT Sat Apr 11 2020

Areas affected...central/eastern Kansas and northwestern Missouri

Concerning...Severe Thunderstorm Watch 101...

Valid 120103Z - 120200Z

The severe weather threat for Severe Thunderstorm Watch 101
continues.

SUMMARY...The severe threat continues across WW 101.

DISCUSSION...Storms that initiated between/west of MHK and EMP have
gradually evolved into a cluster and have moved northeastward toward
the Topeka area.  These storms have primarily been hail producers,
with multiple reports of 1-1.75 inch hail and an isolated 2-inch
report.  These reports are not suprising given the steep-lapse-rate
environment in place across the region.  

Latest guidance/observations suggest that these storms will continue
on their trek northeastward through the I-70 corridor between Topeka
and Kansas City areas, maintaining a hail risk as they do so.  An
estimated 45-50 knot storm motion should place storms near/north of
the Kansas City metro in the 0130Z/0230Z timeframe.

Farther southwest, only isolated, sub-severe convection has managed
to maintain itself across far northwestern Oklahoma, and this
convection may reach southwestern portions of WW 101 over the next
hour.  The extent of the severe threat in this region (upstream of
the eastern Kansas cluster) is a bit uncertain.  Convective trends
will be monitored, but it is likely that portions of the WW near the
I-135 corridor may be cancelled well before the 04Z scheduled
expiration time.

..Cook.. 04/12/2020

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

ATTN...WFO...EAX...TOP...ICT...DDC...

LAT...LON   38939786 39429670 40119491 40209368 39529353 38709401
            38079502 37469645 37329790 37379865 37949851 38939786 

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SPC MD 336

MD 0336 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR CENTRAL/EASTERN KS…NORTH-CENTRAL OK

MD 0336 Image


Mesoscale Discussion 0336
NWS Storm Prediction Center Norman OK
0343 PM CDT Sat Apr 11 2020

Areas affected...Central/Eastern KS...North-Central OK

Concerning...Severe potential...Watch unlikely 

Valid 112043Z - 112245Z

Probability of Watch Issuance...20 percent

SUMMARY...Potential exists for a couple supercells capable of large
hail and damaging wind gusts along the dryline over the next several
hours.

DISCUSSION...Recent surface analysis shows a dryline extending from
near the NE/IA/MO border intersection southwestward through
south-central KS and northwest OK into the TX Panhandle. Visible
satellite imagery shows mostly clear skies across much of
central/eastern KS and north-central OK. Convective initiation
recently occurred over north-central OK along this dryline, which
may be a sign of things to come as the front continues eastward and
strong moisture advection persists across the region. This moisture
advection should help offset the effects of boundary-layer mixing
somewhat, resulting in little to no CINH as the dryline moves
through. 

Given the amount of dry air aloft, updrafts may initially struggle
but steep mid-level lapse rates (and resulting strong buoyancy) and
increasing vertical shear should compensate somewhat, resulting in
the potential for a couple supercells. Primary threat will be large
hail but damaging downburst winds also seem probable with any more
robust updrafts. Storm coverage is expected to remain isolated,
preclude higher watch probability, but trends will be monitored
closely.

..Mosier/Grams.. 04/11/2020

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

ATTN...WFO...EAX...TSA...TOP...ICT...OUN...DDC...

LAT...LON   36719882 37649767 39289610 39019506 37299551 36459638
            35949725 35769825 35989869 36719882 

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SPC MD 299

MD 0299 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PORTIONS OF NORTHERN WEST VIRGINIA

MD 0299 Image


Mesoscale Discussion 0299
NWS Storm Prediction Center Norman OK
0606 PM CDT Tue Apr 07 2020

Areas affected...Portions of northern West Virginia

Concerning...Severe potential...Watch unlikely 

Valid 072306Z - 080030Z

Probability of Watch Issuance...20 percent

SUMMARY...A lone supercell is in progress across northern West
Virginia, which is expected to persist for at least a few more
hours, with large hail being the main threat. A few very large (2+
inch) stones are possible. The storm may begin to gradually weaken
as it begins to outpace the instability axis.

DISCUSSION...A mature supercell is currently moving across Doddridge
County, West Virginia, with a 40 kft top, and 60+ dBZ extending past
the -20C layer. As such, severe hail may be occurring with this
storm, with some significant severe hail possible. This supercell is
associated with a subtle, embedded mid-level impulse which is
currently propagating around the synoptic-scale ridge in place.
Associated with this ridge is an EML plume and steep mid-level lapse
rates exceeding 7 C/km, with the eastward most extent of this plume
emanating into West Virginia. While MLCAPE has remained modest (i.e.
500-1000 J/kg), effective bulk shear values exceeding 40 knots has
promoted storm organization and mid-level rotation amidst cold
temperatures aloft (-17 C at 500 mb), hence the severe hail
potential. 

However, the airmass gradually becomes less stable with eastward
extend, and with nocturnal stabilization expected in the next few
hours, a gradual weakening trend is expected, as supported by some
of the latest high-resolution model guidance.

..Squitieri.. 04/07/2020

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

ATTN...WFO...PBZ...RLX...

LAT...LON   39307975 39127949 38937954 38767965 38677989 38778049
            38978096 39208121 39498123 39628073 39307975 

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SPC MD 292

MD 0292 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PORTIONS OF FAR SOUTHEASTERN ND…NORTHEASTERN SD…AND CENTRAL MN

MD 0292 Image


Mesoscale Discussion 0292
NWS Storm Prediction Center Norman OK
0156 AM CDT Tue Apr 07 2020

Areas affected...Portions of far southeastern ND...northeastern
SD...and central MN

Concerning...Severe potential...Watch unlikely 

Valid 070656Z - 070930Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated large hail may occur through the early morning
hours. Watch issuance remains unlikely.

DISCUSSION...A couple of storms have gradually intensified over the
past hour across far southeastern ND into west-central MN. This is
probably related to the eastward translation of a 50-60 kt westerly
mid-level jet over the Dakotas, and a slight increase in a
southwesterly low-level jet. Steep 700-500 mb lapse rates were noted
on the 00Z ABR sounding, which is supporting around 500-1250 J/kg of
MUCAPE per recent mesoanalysis estimates. Recent VWPs from KMPX and
KABR show strong speed shear from the top of the low-level inversion
to the equilibrium level. This shear will likely continue to support
the potential for organized storms, with mainly a large hail threat
due to their elevated nature. The overall severe risk is expected to
remain rather isolated through the early morning, and watch issuance
appears unlikely at this time.

..Gleason/Thompson.. 04/07/2020

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

ATTN...WFO...DLH...MPX...FGF...ABR...

LAT...LON   45649336 45549401 45669522 45639622 45509688 45249824
            45509830 45949796 46549655 46639538 46509404 46179350
            45649336 

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SPC MD 267

MD 0267 CONCERNING TORNADO WATCH 74…75… FOR NORTHERN AL…MIDDLE TN…FAR SOUTH-CENTRAL KY

MD 0267 Image


Mesoscale Discussion 0267
NWS Storm Prediction Center Norman OK
0150 AM CDT Sun Mar 29 2020

Areas affected...Northern AL...Middle TN...Far South-Central KY

Concerning...Tornado Watch 74...75...

Valid 290650Z - 290815Z

The severe weather threat for Tornado Watch 74, 75 continues.

SUMMARY...The threat for all severe hazards, include brief
tornadoes, will continue across middle TN and northern AL for the
next few hours. Less favorable downstream environment is expected to
preclude new watch issuance but short-lived, local watch extensions
may needed.

DISCUSSION...Radar imagery of the ongoing cluster of storms over the
southern portion of middle TN has shown an increase in forward speed
over the past half hour or so. Echo tops have also increased during
this time. These observations suggest a continued threat for severe
will likely exist downstream of these storms for at least the next
hour or so. Primary threat with this cluster is strong wind gusts,
although an brief embedded tornado and/or hail also remain possible.
Storm motion of this cluster was estimated to be northeast at 60 kt,
taking it to the edge of Tornado Watch 74 around 0730Z. 

This fast northeastward motion will take the cluster ahead of the
ongoing moisture return into a thermodynamic environment
characterized by strong MLCIN, which should lead to a diminishing of
storm intensity. Isolated damaging wind gusts will still be possible
and short-lived, local watch extensions may needed. However, the
limited spatial and temporal severe threat will likely preclude new
watch issuance downstream. 

A few stronger cells have also been noted within the line over
northwest AL. Estimated storm motion within these cells is
northeastward at 50 kt, taking them to the central AL/TN border
around 0700Z. Recent UAH SWIRLL soundings from Courtland AL and
Huntsville AL both show a warm layer around 700 mb, which is likely
leading to reduced updraft strength. Even so, the strong vertical
shear will likely compensate for this reduced instability, leading
to a continued severe threat for the next few hours.

..Mosier.. 03/29/2020

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

ATTN...WFO...MRX...JKL...FFC...LMK...OHX...HUN...

LAT...LON   35858663 36468598 36878469 36358421 35548438 34678560
            34478766 35858663 

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