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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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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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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SPC MD 34

MD 0034 CONCERNING HEAVY SNOW FOR NORTHEAST OK…SOUTHEAST KS

MD 0034 Image


Mesoscale Discussion 0034
NWS Storm Prediction Center Norman OK
0821 AM CST Sat Jan 11 2020

Areas affected...northeast OK...southeast KS

Concerning...Heavy snow 

Valid 111421Z - 111615Z

SUMMARY...A short duration (1-2 hours) of heavy snowfall rates
around 1 inch per hour is expected this morning.

DISCUSSION...Radar imagery during the 7-8am CST period has shown a
blossoming of precipitation across north-central OK into southeast
KS as mid-level ascent becomes maximized over this region.  Cushing,
OK recently reported heavy snow as of 755am CST.  Forecast soundings
in northeast OK show 700-500 mb lapse rates around 7 degrees C per
km and weak upright instability (50-100 J/kg MUCAPE).  Therefore,
weak convection resulting in bursts of heavy snow are seemingly
likely during the next 2 hours as the precipitation shield gradually
pivots east across northeast OK and southeast KS.

..Smith.. 01/11/2020

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

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

LAT...LON   35759642 36629657 37859632 38199573 38099525 37719506
            35809569 35629611 35759642 

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SPC MD 27

MD 0027 CONCERNING TORNADO WATCH 7… FOR WESTERN TN…FAR EASTERN AR…NORTHWEST MS

MD 0027 Image


Mesoscale Discussion 0027
NWS Storm Prediction Center Norman OK
0352 AM CST Sat Jan 11 2020

Areas affected...Western TN...Far Eastern AR...Northwest MS

Concerning...Tornado Watch 7...

Valid 110952Z - 111115Z

The severe weather threat for Tornado Watch 7 continues.

SUMMARY...Conditions remain supportive of organized thunderstorms
capable of strong wind gusts and embedded QLCS tornadoes. A new
watch will likely be needed downstream by 11Z across northern MS and
western TN.

DISCUSSION...Storms within the portion of the convective line
affected far eastern AR, western TN, and northwestern MS appear to
be a bit stronger and better organized. This is evidenced by the
forward surges and higher storm tops recently observed. The already
strong vertical shear over the region has increased over the past 2
hours. Observations from the NQA VAD show 0-3 km storm-relative
helicity increased from around 700 m2/s2 two hours ago to over 950
m2/s2 on the 0924Z observation. Thermodynamic conditions have
remained fairly constant, with temperatures in the upper 60s/low
70s, dewpoints in the mid 60s, and MLCAPE around 500-1000 J/kg.
These conditions remain supportive of organized thunderstorms
capable of strong wind gusts and embedded QLCS tornadoes.

..Mosier.. 01/11/2020

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

ATTN...WFO...MEG...JAN...LZK...

LAT...LON   35449055 36298974 35798840 33488980 33289175 35449055 

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SPC MD 13

MD 0013 CONCERNING FREEZING RAIN FOR PORTIONS OF CENTRAL/EASTERN KS INTO FAR SOUTHEASTERN NE…NORTHWESTERN MO…AND SOUTHERN IA

MD 0013 Image


Mesoscale Discussion 0013
NWS Storm Prediction Center Norman OK
1254 PM CST Fri Jan 10 2020

Areas affected...Portions of central/eastern KS into far
southeastern NE...northwestern MO...and southern IA

Concerning...Freezing rain 

Valid 101854Z - 110100Z

SUMMARY...A mix of freezing rain, sleet, and snow will likely occur
through the remainder of this afternoon and into the early evening.
Freezing rain rates in excess of 0.05 inch per three hours should
occur.

DISCUSSION...18Z surface analysis shows a shallow arctic cold front
advancing south-southeastward across the central Plains. A rapid
transition from isolated hail potential to freezing rain concerns
exists in a narrow corridor along and behind the front across parts
of central/eastern KS into southern IA this afternoon. An area of
ongoing precipitation associated with low-level warm advection
occurring above the surface cold front should continue shifting
northeastward over the next several hours. A pronounced warm nose in
roughly the 900-750 mb layer noted on the 12Z sounding from TOP will
be slow to erode, and complete melting aloft of frozen hydrometeors
should occur initially. Refreezing at the surface will occur behind
the cold front as temperatures rapidly fall into the mid to upper
20s. A few surface observations already show this process occurring,
with light to moderate freezing rain noted from central KS into
northeastern KS, far southeastern NE, and southern IA. Potential
exists for freezing rain rates to exceed 0.05 inch per 3 hours in a
narrow southwest to northeast corridor across this region through
the early evening, with some convective enhancement possible. A
gradual transition to sleet and eventually snow appears likely as
the warm nose aloft slowly erodes.

..Gleason.. 01/10/2020

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

ATTN...WFO...DVN...DMX...EAX...OAX...TOP...ICT...DDC...

LAT...LON   37829891 38409851 39879647 40739515 41439369 41749276
            41629213 41349199 40879229 40249328 39509447 38419621
            37889766 37629837 37829891 

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SPC MD 12

MD 0012 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR PARTS OF SOUTHEASTERN KANSAS AND SOUTHWESTERN MISSOURI

MD 0012 Image


Mesoscale Discussion 0012
NWS Storm Prediction Center Norman OK
1211 PM CST Fri Jan 10 2020

Areas affected...Parts of southeastern Kansas and southwestern
Missouri

Concerning...Severe potential...Watch possible 

Valid 101811Z - 102015Z

Probability of Watch Issuance...60 percent

SUMMARY...Potential for supercells capable of producing tornadoes,
in addition to severe hail, may increase across southeastern Kansas
into southwestern Missouri through 2-4 PM CST.  Trends are being
monitored for the possibility of a new watch, or extending tornado
watch number 2 northward, within the next hour or two.

DISCUSSION...Convection with embedded vigorous thunderstorms
continues to develop north-northeastward with supporting forcing for
large-scale ascent, toward the lower Missouri Valley.  Storms may
still be largely rooted above the boundary layer, within broader
lower/mid tropospheric warm advection.  However, weak to modest
boundary-layer destabilization is ongoing, ahead of a weak frontal
wave which is forecast to migrate across the Chanute KS area toward
the Kansas/Missouri state border area (north of Joplin MO) through
20-21Z.  With at least some further increase of surface dew points
into the lower 60s possible, the environment may become increasingly
conducive to supercells accompanied by the risk for tornadoes, in
addition to severe hail.

..Kerr/Hart.. 01/10/2020

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

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

LAT...LON   38019560 38209382 37919300 36959344 36919418 37049595
            38019560 

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