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Storm Prediction Center Forecast

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SPC Severe Thunderstorm Watch 195

WW 195 SEVERE TSTM NM OK TX 200655Z - 201500Z
WW 0195 Image

Severe Thunderstorm Watch Number 195
NWS Storm Prediction Center Norman OK
155 AM CDT Mon May 20 2019

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Eastern New Mexico
  Oklahoma Panhandle
  Texas Panhandle and South Plains

* Effective this Monday morning from 155 AM until 1000 AM CDT.

* Primary threats include...
  Scattered large hail and isolated very large hail events to 2.5
    inches in diameter likely
  Scattered damaging wind gusts to 70 mph possible

SUMMARY...Thunderstorms should grow in coverage and intensify
through sunrise and beyond, offering predominantly a large-hail
threat for the first few hours, with isolated severe gusts possible.
 As storms organize further into greater moisture and instability
toward sunrise, the damaging-wind risk will increase as well.

The severe thunderstorm watch area is approximately along and 85
statute miles east and west of a line from 55 miles east southeast
of Roswell NM to 25 miles north northeast of Guymon OK. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU5).


REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce


AVIATION...A few severe thunderstorms with hail surface and aloft to
2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 550. Mean storm motion vector


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SPC Severe Thunderstorm Watch 195 Status Reports

WW 0195 Status Updates
WW 0195 Status Image

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SPC - No MDs are in effect as of Mon May 20 07:29:04 UTC 2019

No Mesoscale Discussions are in effect as of Mon May 20 07:29:04 UTC 2019.

SPC Center Public Severe Weather Outlook (PWO)

Public Severe Weather Outlook
PWO Image
0212 AM CDT MON MAY 20 2019

...Outbreak of tornadoes and severe thunderstorms expected over
parts of the southern Plains this afternoon and tonight...

  Northwest Texas
  Western and central Oklahoma

  Numerous tornadoes, several intense and long track
  Widespread damaging winds, some hurricane force
  Widespread large hail, some baseball size

  An outbreak of tornadoes, some potentially long-track and
  violent, is expected today into this evening over portions of
  northwest Texas into western and central Oklahoma. More-isolated
  but still potentially dangerous severe weather, including
  tornadoes, is possible in surrounding parts of Texas, Oklahoma,
  Kansas, and Arkansas.

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 tornado
watch means that conditions are favorable for tornadoes to form
during the next several hours. If a tornado warning is issued for
your area, move to a place of safety, ideally in a basement or
interior room on the lowest floor of a sturdy building.


..Edwards.. 05/20/2019
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SPC May 20, 2019 0600 UTC Day 1 Convective Outlook

SPC 1200Z Day 1 Outlook
Day 1 Outlook Image
Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1256 AM CDT Mon May 20 2019

Valid 201200Z - 211200Z



An outbreak of strong tornadoes and severe thunderstorms is expected
today across parts of the southern and central Plains. In addition,
many of the storms will have very large hail and wind damage. The
severe threat will be concentrated from west Texas and the Texas
Panhandle eastward across Oklahoma, Kansas into western Missouri and
western Arkansas. Additional severe storms with wind damage and hail
will be possible this afternoon from southeast New York into
southern and central New England.

...Tornado Outbreak Expected Across the Southern Plains Today Into

...Southern and Central Plains...
An impressive and potent upper-level trough will move quickly
eastward across the Desert Southwest today as a powerful 75 to 90
knot mid-level jet rounds the base of the trough. Ahead of the
system, a corridor of strong instability is forecast across the
Southern Plains from west Texas into the eastern Texas Panhandle and
eastward into western and central Oklahoma. This combined with steep
mid-level lapse rates and strong low-level shear will be very
favorable for severe storms. As the mid-level jet ejects
northeastward across the southern High Plains this afternoon and
evening, a tornado outbreak is likely across the southern Plains.
The tornado outbreak is expected to continue into the overnight
period. This event should result in a significant threat to life and

RAP forecast soundings late this afternoon along the instability
corridor from Childress, Texas northeastward to Clinton, Oklahoma
show MLCAPE values of 3000 to 4500 J/kg with 0-6 km shear in the 50
to 65 kt range. In addition, hodographs are large and looped with
0-1 km shear values in the 30 to 40 kt range. This environment
should be very favorable for supercells and tornadoes. 0-3 km
storm-relative helicities are forecast to steadily increase from
about 300 m2/s2 in the late afternoon to about 450 m2/s2 by early
evening as an anomalously strong low-level jet becomes better
focused. This will be ideal for a tornado outbreak with strong
tornadoes upstream and to the west of the low-level jet.

The current thinking concerning the details is that the first round
of severe storms will begin early as thunderstorms initiate in west
Texas and move northeastward into the eastern Texas Panhandle by mid
to late morning. Initially, large hail will be the main threat but
as these storms mature, tornadoes will be possible with the stronger
and more dominant cells. Additional supercells with tornado
potential are expected to initiate near the warm front in western
and central Oklahoma. A tornado threat will transition to large hail
and wind damage as the storms move into Kansas to the north side of
the boundary. This first round of severe storms is forecast to move
northeastward, away from the warm sector, allowing for the
development of extreme instability during the mid to late afternoon
from northwest Texas into southwest Oklahoma.

The second round of severe storms is expected to start during the
late afternoon as repeat initiation takes place in west Texas. Rapid
supercell formation is forecast along the I-27 corridor from the
vicinity of Lubbock northward to just south of Amarillo. A cluster
of tornadic supercells is then forecast to move northeastward into
northwest Texas and the southeastern Texas Panhandle during the
early evening. Additional tornadic supercells are forecast to
rapidly develop in southwest Oklahoma and move northeastward into
west-central Oklahoma. At that time, the strengthening low-level jet
will couple with a highly progressive and seasonably strong
mid-level jet, making conditions favorable for long-track strong
tornadoes and possibly violent tornadoes.

The greatest threat for long-track tornadoes will exist along the
corridor from near Lubbock northeastward to Childress, Altus,
Lawton, Clinton to just west of the Oklahoma City and Enid
vicinities. After considerable deliberation, a High risk will be
issued for parts of west Texas, the southeastern Texas Panhandle
into western Oklahoma.

In addition to the tornado threat, conditions will be very favorable
for large hail and wind damage. Strong instability, enhanced
deep-layer shear and steep mid-level lapse rates will make
hailstones of greater than 2 inches in diameter possible with the
more intense supercells, mainly in west Texas and the western half
of Oklahoma. A wind-damage threat will also exist across much of the
southern Plains due to the expected intense nature of the storms.
The wind-damage threat, including some gusts above 70 kt, should
become widespread during the late evening into the overnight period
as squall line organizes and moves quickly eastward across the
southern Plains.

...Southeast New York/New England...
An upper-level trough will move across southern Quebec and the
Northeast today. At the surface, a cold front will advance eastward
across New York and into western New England. Ahead of the front,
surface dewpoints in the mid 60s F should result in destabilization
of the airmass by afternoon from southeast New York into much of
southern and central New England. Scattered thunderstorm development
is expected around midday along the cold front with this convection
moving eastward across the moist sector during the afternoon.
Forecast soundings along the instability axis from Springfield,
Massachusetts northeastward into Vermont at 21Z show MLCAPE values
peaking in the 1000 to 1500 J/kg range and have steep low-level
lapse rates. This combined with 0-6 km shear values around 35 kt
should be sufficient for multicells with wind damage potential. A
few rotating storms with a large-hail threat may also develop.

..Broyles/Wendt.. 05/20/2019

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SPC May 20, 2019 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
1239 AM CDT Mon May 20 2019

Valid 211200Z - 221200Z


Thunderstorms capable of damaging wind gusts and a few tornadoes are
possible from the middle Mississippi Valley south into the Arklatex
on Tuesday.

Mid-latitude cyclone over the central High Plains Tuesday morning is
expected to move northeastward throughout the day, reaching the
northern Plains by early Wednesday. Strong southerly/southeasterly
flow aloft throughout the eastern periphery of the cyclone will
spread from the southern/central Plains northeastward into the
upper/mid MS Valley. Surface low associated with this mid-latitude
cyclone will move northward across the central Plains while
occluding. This occlusion process will result in eventual
displacement between the warm sector (over the mid MS Valley) and
the surface low (over the central Plains) after 21Z.

...Lower MO/Mid MS Valleys into the Arklatex...
Expansive convective line will likely be ongoing at the beginning of
the period from KS through north TX. This line is expected to
continue progressing eastward/northeastward throughout the day,
moving through AR, MO, and southern/central IL. Kinematic fields
associated with the mid-latitude cyclone mentioned in the synopsis
are impressive, with 80 kt of southerly 500 mb flow atop southerly
850 mb flow of 40-50 kt expected across MO by 21Z. The result is
very long hodographs and strong deep layer (i.e. 0-6 km) shear
around 60-70 kt. A warm front will gradually shift northeastward
across MO Tuesday morning, with dewpoints in the mid to upper 60s
anticipated ahead of the line as it moves into MO and AR during the
early afternoon. Also, the a shortwave trough rotating through the
parent cyclone is expected to catch up to the preceding convective

All of these factors suggest a reintensification of the line is
likely, with some increased forward propagation anticipated.
Consequently, higher coverage of damaging wind gusts is possible and
a 30% probability area has been added from northern MO/far
west-central IL southward into northern AR. Mesovortices/QLCS
tornadoes are also possible, particularly in areas where the
convective line surges forward. 

...Central/Eastern NE...Northeastern KS...
A late-afternoon severe threat may develop across the region as the
cold temperatures aloft associated with the upper low move over a
well-mixed boundary layer. Instability is modest but favorable
shear, particularly in areas near the warm front where the surface
winds remain southeasterly, could support a few storms capable of
hail and maybe even a brief tornado.

Tornado:   5%     - Slight
Wind:     30%     - Enhanced
Hail:     15%     - Slight

..Mosier.. 05/20/2019

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SPC May 20, 2019 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
0224 AM CDT Mon May 20 2019

Valid 221200Z - 231200Z


Thunderstorms capable of hail are possible late Wednesday night into
early Thursday morning from the southern High Plains into the
central Plains.

Complex upper pattern evolution is expected on Wednesday as two
strong shortwave troughs, one over the northern Plains at 12Z and
the other over southern NV/CA, pivot cyclonically around the deep
upper troughing in place from the Canadian Prairie provinces through
southern CA. At the same time, southeastern CONUS ridging will build
northward/northwestward into the Plains and OH Valley. By the end of
the period, an amplified western CONUS trough/eastern CONUS ridge
pattern is expected, with strong mid-level flow between these two
features from the southern High Plains to the upper MS Valley.

At the surface, the primary feature of interest will be a deepening
lee low across the southern High Plains, which helps to increase the
pressure gradient. Resulting southeasterly winds will augment the
return flow across the southern and central Plains. Current
expectation is for mid 60s dewpoints to extend as far west as the TX
Panhandle and as far north as northern KS by 12Z Thursday.

...Southern/Central Plains...
Rising heights associated with the building southeast CONUS ridging
will likely limit thunderstorm chances throughout much of the day.
However, development of a strong low-level jet is expected during
the evening and overnight. Resulting warm-air advection into the
sharpening lee trough/dryline across west TX and into the warm front
across KS will provide the lift need for convective initiation.
Steep lapse rates and strong vertical shear support elevated
supercells and an attendant hail risk. Uncertainty regarding
coverage precludes higher than 5% probability with this outlook.

..Mosier.. 05/20/2019

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SPC Day 1 Fire Weather Outlook

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook Image
Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0118 AM CDT Mon May 20 2019

Valid 201200Z - 211200Z


A potent mid-level wave will approach the southern High Plains
today. An associated mid-level jet will round the base of this
trough and bring very stout winds across portions of the southern
Rockies/High Plains. In eastern Colorado, a deepening surface
cyclone will increase the surface pressure gradient throughout the
period. Winds across southern New Mexico and the adjacent High
Plains will range from 20-30 mph with higher speeds possible in a
few locations, particularly beneath the jet core. Downslope flow off
of the Sierra Madre Occidental will induce afternoon RH between
5-20%. A broader area of elevated fire weather concerns across
southern/central New Mexico and into the Trans-Pecos will exist
during the afternoon. Much of this area will not see critical
concerns due to relatively low fuel loading for this time of year.
Critical fire weather concerns will likely manifest in portions of
southwest New Mexico and far West Texas where ERCs are near normal
and fuels are critically dry. Furthermore, this region should see
less upper-level cloud cover than other areas as the trough
approaches, per forecast soundings. The eastern edge of the elevated
area has been shifted to the west as overnight observations and
model guidance show precipitation developing in portions of eastern
New Mexico.

..Wendt.. 05/20/2019

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

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SPC Day 2 Fire Weather Outlook

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook Image
Day 2 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0154 AM CDT Mon May 20 2019

Valid 211200Z - 221200Z


As one upper-level shortwave trough ejects into the Plains, another
will begin to move into the Southwest. A ribbon of strong mid-level
flow will remain across the Southwest into the southern Plains on
D2/Tuesday. A still-strengthening lee cyclone in eastern Colorado
will continue to foster a strong surface pressure gradient. These
two features will combine to bring 20-30 mph, with locally higher
speeds, to portions of southern New Mexico and the southern High
Plains. While temperatures are expected to be somewhat cooler,
downslope flow will still help to lower afternoon RH into the 5-20%
range. Elevated fire weather concerns will exist from far southeast
Arizona into portions of central/southern New Mexico and the Trans
Pecos. Areas of the Texas Panhandle will likely see strong westerly
winds and dry conditions, but fuel states and copious precipitation
on D1/Monday will limit any threat. Fuels will continue to be more
receptive in southwest New Mexico into far West Texas. Here,
critical fire weather concerns will exist for a second straight day.
Some consideration was given to expanding the critical area, but
latest SWCC fuel guidance still shows marginally receptive fuels
elsewhere. Given the dry/windy conditions expected on D1/Monday,
expansion could occur in future outlooks should fuels become more

..Wendt.. 05/20/2019

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

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