SPC MD 205

MD 0205 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR SOUTH-CENTRAL NEBRASKA AND FAR NORTHERN KANSAS

MD 0205 Image


Mesoscale Discussion 0205
NWS Storm Prediction Center Norman OK
0201 PM CDT Thu Mar 19 2020

Areas affected...south-central Nebraska and far northern Kansas

Concerning...Severe potential...Watch unlikely 

Valid 191901Z - 192100Z

Probability of Watch Issuance...20 percent

SUMMARY...Convection is intensifying near a frontal boundary across
the region.  Large hail and isolated damaging wind gusts are the
primary threat.  A WW is not anticipated, however, given the
isolated nature of the threat.

DISCUSSION...Cooling aloft associated with an advancing vort max
across east-west-central Kansas and sustained surface heating was
contributing to deepening, lightning-producing convection near a
surface boundary extending from near GLD to HSI.  These storms are
in an environment characterized by modest instability (250-1000 J/kg
MUCAPE) and appreciable deep shear (35-40 kts), with storm motion
vectors largely perpendicular to the initiating surface bounday. 
This should result in a tendency for most convection to be undercut,
though 7-8 C/km mid-level lapse rates may support isolated instances
of large hail in the strongest cells.  Any threat for surface wind
gusts or updraft rotation may occur if storms interact favorably
with the initiating boundary, though this potential appears to be
quite low at this time.  These storms should continue to spread
north-northeast with time, with the already limited severe risk
persisting through the next few hours.

Given the isolated nature of the threat, a WW issuance is not
anticipated.

..Cook/Dial.. 03/19/2020

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

ATTN...WFO...OAX...TOP...GID...LBF...GLD...

LAT...LON   40789851 40799842 40839762 40629734 40359739 40089763
            40029768 39669925 39120137 39150183 39340208 39700200
            39980145 40030107 40110093 40489969 40789851 

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SPC MD 163

MD 0163 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR CENTRAL AND SOUTHEASTERN KANSAS INTO NORTHEASTERN OKLAHOMA/SOUTHWESTERN MISSOURI

MD 0163 Image


Mesoscale Discussion 0163
NWS Storm Prediction Center Norman OK
0202 AM CDT Wed Mar 11 2020

Areas affected...central and southeastern Kansas into northeastern
Oklahoma/southwestern Missouri

Concerning...Severe potential...Watch unlikely 

Valid 110702Z - 110900Z

Probability of Watch Issuance...20 percent

SUMMARY...A few stronger storms -- capable of producing marginally
severe hail -- should continue to gradually evolve this morning
within a broader area of convection, spreading east-southeastward
with time across Kansas.

DISCUSSION...Latest radar imagery shows convection increasing in
coverage across the central Kansas vicinity, with some increase in
storm intensity also noted.  This is occcurring as low-level
moistening/warming is occurring above a surface-based stable layer,
associated with a 60 kt south-southwesterly low-level jet now noted
per KVNX WSR-88D in northern Oklahoma.  

This warming is occurring beneath a layer of modest cooling as a
mid-level vorticity lobe continues shifting east-southeastward out
of Nebraska and into northern Kansas.  The steepening of lapse rates
as a result of these two processes is yielding the observed uptick
in convective intensity, and this trend is expected to continue over
the next few hours.

With flow aloft veering to westerly aloft, shear sufficient to
enhance storm intensification is present.  At this time, it appears
that a relatively deep, substantially stable boundary layer will
preclude appreciable wind risk.  Primary severe potential with the
evolving storms will therefore likely remain hail in the 1 to 1.5"
range.  Watch probability -- while low at this time -- could
increase later in the morning as storms spread into the Ozarks
region.

..Goss/Edwards.. 03/11/2020

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

ATTN...WFO...SGF...TSA...TOP...ICT...DDC...

LAT...LON   38609953 38889943 38879807 38759776 38649704 38219553
            37609408 36799447 36479517 36949603 38609953 

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SPC MD 162

MD 0162 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR WESTERN/SOUTHWESTERN MISSOURI…FAR SOUTHEASTERN KANSAS…AND FAR NORTHEASTERN OKLAHOMA

MD 0162 Image


Mesoscale Discussion 0162
NWS Storm Prediction Center Norman OK
0341 PM CDT Mon Mar 09 2020

Areas affected...western/southwestern Missouri...far southeastern
Kansas...and far northeastern Oklahoma

Concerning...Severe potential...Watch unlikely 

Valid 092041Z - 092245Z

Probability of Watch Issuance...20 percent

SUMMARY...An isolated risk of damaging wind gusts may evolve with
gradually increasing convection across east-central Kansas over the
next couple hours or so.  A WW is not anticipated for this activity.

DISCUSSION...Latest radar mosaic/satellite imagery indicate a
gradually deepening axis of convection located from near OJC
(Olathe, KS) south-southwestward to near CNU (Chanute, KS).  These
storms were oriented along a pre-frontal trough migrating eastward
across the region.  The storms were in an environment characterized
by weak instability (250-750 J/kg MUCAPE) but strong low-level and
deep shear, which should favor organization and some updraft
rotation as long as storms can deepen and mature.  Continued
destabilization is expected owing to low-level warm advection amidst
40-45 kt southwesterly 850 hPa flow and cooling aloft associated
with an advancing mid-level wave over central Kansas.  Should this
convection mature, CAMs indicate a primarily cellular convective
mode, which suggests a risk for isolated damaging wind gusts and
perhaps a tornado.

The overall risk is mitigated by weak instability, however.  This
should preclude a WW issuance although convective trends will be
monitored through the evening.

..Cook/Moore/Hart.. 03/09/2020

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

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

LAT...LON   38189519 38709485 39069394 39129317 38789266 38059263
            37209313 36809390 36679503 36879543 37459541 38189519 

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SPC Mar 9, 2020 0730 UTC Day 3 Severe Thunderstorm Outlook

SPC 0730Z Day 3 Outlook

Day 3 Outlook Image

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0228 AM CDT Mon Mar 09 2020

Valid 111200Z - 121200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WEDNESDAY ACROSS
THE OZARK PLATEAU VICINITY...

...SUMMARY...
Strong thunderstorms may impact portions of the Ozark Plateau
vicinity Wednesday, accompanied by at least some risk for severe
weather.

...Synopsis...
The transition to a less progressive regime characterized by
increasing blocking appears likely to continue across the eastern
Pacific.  As this occurs, little, if any, eastward progression of
the mid-level troughing and embedded closed low near and southwest
of the southern California coast is forecast, and the closed low may
actually shift southward some, away from the coast during this
period. 

Broad downstream ridging may generally be maintained across much of
the Gulf coast region.  This may include rising heights across parts
of the Mid South, in the wake of one short wave trough within a much
more progressive branch of westerlies across southern Canada and the
northern tier of the United States.  However, a more vigorous
perturbation is forecast to dig across the central international
border area, and to the east of the northern Rockies, and this could
lead to some suppression of the crest of the southern branch
ridging, across the central Plains by late Wednesday night.  Models
indicate that this impulse will be accompanied by a southeastward
migrating cyclone across the Canadian Prairies, and broad deepening
surface troughing  across the northern Plains/upper Mississippi
Valley, south-southwestward through the south central Plains by 12Z
Thursday.

As all this occurs, instability supportive of areas of widely
scattered to scattered thunderstorm activity will largely be
confined to the southern tier of the United States.  East of the
Rockies, this is expected to generally remain along and south of a
weakening frontal zone, initially extending across the southern Mid
Atlantic coast into the Ozark Plateau and south central Plains. 
With low-level flow above the surface maintaining a substantial
westerly component, little further moisture influx is expected off
the Gulf of Mexico.  But lower to mid 60sF surface dew points inland
may contribute to weak to moderate boundary layer destabilization
across parts of west central and northern Texas into the Ozark
Plateau, and perhaps eastward through northern portions of the
eastern Gulf states.

...Ozark Plateau vicinity...
Models suggest that forcing for ascent near the southern periphery
of the lead northern branch short wave trough may be contributing to
a sustained, evolving cluster of thunderstorms across parts of
northeastern Oklahoma at the outset of the period.  This convection
is expected to be aided by inflow of most unstable CAPE on the order
of 500-1000 J/kg, on the nose of a 30-40 kt 850 jet accompanying a
50+ kt 500 mb speed maximum, contributing to an environment at least
marginally conducive to severe hail and wind.

It appears that this activity could continue east-southeastward
along the frontal zone across the Ozark Plateau into portions of the
Mid South during the day Wednesday.  How long and how far remain
unclear, as aforementioned large-scale pattern developments result
in weakening forcing for this activity at some point.  There are
discrepancies within the various model output concerning this.  The
latest NAM, for example, suggests that a continuation of vigorous
convection east-southeastward across parts of northern/central
Alabama and Georgia might not be out of the question by late
Wednesday evening.  This will need to be monitored for possible
adjustments in later outlooks for this time period.

..Kerr.. 03/09/2020

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SPC Mar 9, 2020 0600 UTC Day 2 Convective Outlook

SPC 0600Z Day 2 Outlook

Day 2 Outlook Image

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1136 PM CDT Sun Mar 08 2020

Valid 101200Z - 111200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TUESDAY NIGHT
ACROSS PARTS OF THE SOUTHERN CENTRAL PLAINS INTO OZARK PLATEAU...

...SUMMARY...
Strong thunderstorms may impact parts of the south central Plains
into Ozark Plateau Tuesday night, accompanied by at least some risk
for severe weather.

...Synopsis...
Models continue to suggest that mid/upper flow may begin to become
less progressive and characterized by increased blocking across the
eastern Pacific during this period.  As this occurs, a closed
mid-level low, initially over the southern mid-latitude and
subtropical eastern Pacific, will be slow to progress eastward. 
Within larger-scale troughing, it appears that the low may begin to
weaken while elongating northeastward across the central and
southern California coast through the Sierra Nevada and lower
Colorado Valley.  The mid-level cold core may remain offshore
through much of the period.

Downstream of the mid-level low and troughing, mid-level ridging may
be maintained across the southern Rockies and southern Plains. 
However, there may be some suppression of the ridging by late
Tuesday night, mainly north of the Red River.  Models indicate that
this could occur in response to a short wave trough digging across
the northern Plains and upper Mississippi Valley, within a much more
progressive branch of westerlies across the northern mid-latitude
Pacific through southern Canada and the northern tier of the United
States.

In association with a couple of downstream perturbations, a modest
surface low is forecast to migrate from the southwestern
Quebec/Ontario border vicinity into the Canadian Maritimes, with a
trailing cold front advancing southeastward through much of the
Northeast, Mid Atlantic and Ohio Valley.  The western flank of the
front is forecast to stall across the south central Plains, and
perhaps return slowly northward, as another weak to modest surface
low migrates southeastward out of Colorado, across the
Texas/Oklahoma Panhandle region by late Tuesday night.

To the south of the surface front, further boundary layer
moistening, coupled with steepening lower/mid tropospheric lapse
rates, may yield weak to moderate boundary-layer CAPE (500-1000
J/kg) across much of central/eastern Texas into parts of the lower
Mississippi Valley by late Tuesday afternoon.  However, this will
largely take place beneath the mid-level ridging, where warm layers
aloft may tend to inhibit deep convective development, and the
potential for thunderstorms is largely conditional on uncertain
forcing for ascent.

...South central Plains into Ozark Plateau...
Potential for thunderstorm initiation near the intersection of the
initially stalled surface front and deepening lee surface troughing
across northwest Texas now appears too conditional to maintain even
low severe probabilities.  However, a strengthening low-level warm
advection regime to the northeast may still provide a focus for
scattered strong thunderstorms, mainly after 11/06Z Tuesday night,
as elevated moisture return above the surface front contributes to
most unstable CAPE of 500-1000 J/kg.  

Model forecast soundings suggest that the environment may become
conducive to storms capable of producing marginally severe hail.  A
developing area of enhanced lift, aided by 850 mb low-level jet
strengthening to 30-40+ kt may support a small upscale growing and
organizing cluster of storms across parts of south central Kansas
into northeastern Oklahoma.  In addition to some hail, this cluster
could also support a few strong surface gusts.

..Kerr.. 03/09/2020

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SPC MD 144

MD 0144 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR MUCH OF WEST VIRGINIA…SOUTHWESTERN PENNSYLVANIA…WESTERN MARYLAND…AND SOUTHEASTERN OHIO

MD 0144 Image


Mesoscale Discussion 0144
NWS Storm Prediction Center Norman OK
1222 PM CST Tue Mar 03 2020

Areas affected...much of West Virginia...southwestern
Pennsylvania...western Maryland...and southeastern Ohio

Concerning...Severe potential...Watch unlikely 

Valid 031822Z - 032015Z

Probability of Watch Issuance...20 percent

SUMMARY...Low-topped convection may produce isolated damaging wind
gusts over the course of the afternoon.  A WW issuance is not
anticipated for this activity.

DISCUSSION...Relatively low-topped convection has increased in
coverage over the past half hour or so, with lightning flashes
observed near stronger cores.  Thermodynamic profiles are only
marginally unstable across the discussion area, although western
portions of the discussion area are beginning to be influenced by
substantial cooling aloft associated with an approaching shortwave. 
The cooling/destabilization has resulted in about 250-500 J/kg
MUCAPE which is supporting the ongoing convection, and the
combination of this cooling and surface heating will result in just
enough destabilization for convection to traverse the discussion
area over the next two to three hours or so.  

Fast flow aloft (50-70 kt near the top of updrafts) and downward
momentum processes may result in isolated damaging wind gusts
through the afternoon especially as convection continues to deepen
and/or organize into linear segments.  The overall severe threat
appears to be too low to necessitate a WW issuance at this time,
however.

..Cook/Hart.. 03/03/2020

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

ATTN...WFO...CTP...LWX...PBZ...RLX...

LAT...LON   40697953 40298090 39338222 38808256 38168198 38447992
            38977834 39677813 40117808 40557853 40697953 

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SPC MD 105

MD 0105 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR NORTHERN VA…DISTRICT OF COLUMBIA…CENTRAL MD

MD 0105 Image


Mesoscale Discussion 0105
NWS Storm Prediction Center Norman OK
0556 AM CST Fri Feb 07 2020

Areas affected...northern VA...District of Columbia...central MD

Concerning...Severe potential...Watch unlikely 

Valid 071156Z - 071300Z

Probability of Watch Issuance...5 percent

SUMMARY...Strong to localized severe gusts (50-60 mph) are possible
with a narrow, low-topped convective band rapidly moving across
northern VA and the greater D.C. area during the 12z-1330z period.

DISCUSSION...KLWX radar imagery shows an intensifying band of
low-topped convection with a few lightning flashes with the deeper
convection exhibiting 20kft echo tops.  Surface analysis shows a
surface low immediately northwest of D.C. developing to the
east-northeast.  A narrow plume of weakly buoyant air, with surface
temperatures in the upper 50s and dewpoints in the upper 50s, is
located downstream of the convective band over northern/eastern VA
into MD.  Objective analysis indicates around 250 J/kg SBCAPE with
40 kt effective shear.  Given the strong, deep forcing for ascent
co-located with weak instability, it is possible a few strong to
locally severe gusts may accompany the bowing portions of the
convective band.  The damaging-gust threat appears too confined in
space/time to warrant a severe thunderstorm watch.

..Smith/Edwards.. 02/07/2020

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

ATTN...WFO...AKQ...LWX...

LAT...LON   39047766 39257701 39187648 38647665 38297716 37927819
            39047766 

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SPC MD 60

MD 0060 CONCERNING FREEZING RAIN FOR FAR NORTHEAST KS INTO NORTHERN MO AND CENTRAL IL

MD 0060 Image


Mesoscale Discussion 0060
NWS Storm Prediction Center Norman OK
0945 AM CST Fri Jan 17 2020

Areas affected...far northeast KS into northern MO and central IL

Concerning...Freezing rain 

Valid 171545Z - 172145Z

SUMMARY...Freezing rain and sleet will continue to lift northeast
across northern MO into central IL through the afternoon hours.

DISCUSSION...Freezing rain, with some areas reporting sleet as well,
extended along the I-70 corridor from the Kansas City metro area to
St. Louis this as of 1530z. Across southwest MO/southeast KS,
temperatures are beginning to climb above freezing in continued
strong warm advection regime. As precipitation continue to spread
northeast across northern MO into central OK, periods of freezing
rain and sleet will continue into this afternoon. Surface
temperatures across the MCD area are generally in the mid 20s to
near 30 degrees with forecast thermodynamic profiles showing
continued support for freezing rain and sleep through much of the
day. Surface temperatures will slowly warm from south to north, with
the freezing line expected to be north of the I-70 corridor by 21z,
allowing frozen precip types to transition to rain. Precipitation
rates have been as high as 0.10 in/hr per Local Storm Reports from
WFO Springfield MO. Rates will mostly be lighter, at a few
hundredths of an inch per hr, though this seems like a reasonable
maximum rate in brief heavier showers.

..Leitman.. 01/17/2020

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

ATTN...WFO...PAH...ILX...LSX...DVN...SGF...EAX...OAX...TOP...

LAT...LON   40409184 40469329 40449394 40309482 40179549 39709570
            39209532 38319351 38129240 38069099 38258966 38538897
            38868840 39338816 39678828 39968897 40189011 40409184 

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SPC MD 58

MD 0058 CONCERNING FREEZING RAIN FOR PORTIONS OF CENTRAL/EASTERN KS AND WESTERN/CENTRAL MO

MD 0058 Image


Mesoscale Discussion 0058
NWS Storm Prediction Center Norman OK
0320 AM CST Fri Jan 17 2020

Areas affected...Portions of central/eastern KS and western/central
MO

Concerning...Freezing rain 

Valid 170920Z - 171515Z

SUMMARY...Light to moderate freezing rain will continue to spread
northward across parts of Kansas and Missouri this morning. Freezing
rain rates around 0.05 inch per hour remain likely. The greatest
freezing-rain rates should focus across a small part of
central/eastern Kansas. Rates up to 0.10 inch/hour will be possible
across this area.

DISCUSSION...A broad area of precipitation is ongoing this morning
across the southern/central Plains in association with strong
low-level warm advection preceding a northeastward-moving shortwave
trough. Some of this precipitation is occurring atop a shallow
near-surface sub-freezing layer, which is supporting predominately
freezing rain from parts of the TX Panhandle/western OK
northeastward into much of central/eastern KS and western MO early
this morning. The surface wetbulb freezing line similarly extends
from southwest to northeast across west TX and much of OK. Numerous
freezing rain reports have been observed across central/eastern KS
in the past couple of hours. Freezing-rain rates around 0.05 inch
per hour remain likely over much of this area based on recent
observations. The strongest forcing for ascent should focus across
parts of central/eastern KS through 15Z, where a relatively narrow
corridor of greater freezing rain rates may occur. Up to 0.10 inch
per hour rates appear possible across this area. Also, ice accretion
may be enhanced with temperatures in the mid to upper 20s.

With pronounced low-level warm advection expected to continue across
central/eastern KS over the next several hours, surface temperatures
will gradually warm above freezing from south to north across mainly
southeastern KS. A transition from freezing rain to rain will
likewise occur.

..Gleason.. 01/17/2020

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

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

LAT...LON   37039937 37989952 38579932 39039890 39509738 39579633
            39479493 39309379 38929272 38299218 37749203 37309209
            36959242 36629302 36589342 36959406 37319463 37409619
            37279711 37029797 37039937 

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SPC MD 57

MD 0057 CONCERNING FREEZING RAIN FOR NORTHERN OKLAHOMA…SOUTHERN KANSAS…SOUTHWESTERN MISSOURI

MD 0057 Image


Mesoscale Discussion 0057
NWS Storm Prediction Center Norman OK
1117 PM CST Thu Jan 16 2020

Areas affected...Northern Oklahoma...Southern Kansas...Southwestern
Missouri

Concerning...Freezing rain 

Valid 170517Z - 170915Z

SUMMARY...Freezing rain will increase across southern Kansas and
southwestern Missouri over the next 2-4 hours. Rates may approach
0.05"/hr.

DISCUSSION...Large canopy of precipitation is gradually expanding
north across the southern/central Plains within a corridor of
isentropic ascent. At the surface, a wedge of sub-freezing
boundary-layer air is gradually shallowing across northern
OK/southern KS as strong low-level warm advection persists ahead of
a short-wave trough. With significant warming expected in the 1-3km
layer, the onset of any mixed precipitation should change to
freezing rain as the morning progresses. Profiles along/north of
I-70 are currently quite dry in the lowest 1km, thus several hours
of moistening will be necessary before heavier, mixed precipitation
develops across this region.

..Darrow.. 01/17/2020

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

ATTN...WFO...SGF...EAX...TOP...ICT...OUN...DDC...AMA...

LAT...LON   38389882 38419546 37889408 37359375 36989403 37209502
            36989690 36349904 37000029 37930006 38389882 

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