Les dejo la reciente actualizacion del convective outlook de hoy.
% de tornados.
% de vientos.
% de granizo.
Discusion:
Day 1 Convective Outlook AMEND 1
NWS Storm Prediction Center Norman OK
0350 PM CDT Thu Mar 30 2017
Valid 302043Z - 311200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE OHIO VALLEY AND MIDWEST...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE MIDWEST
SOUTHWARD INTO THE FLORIDA PANHANDLE...
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER A LARGE
PART OF THE MIDWEST INTO THE SOUTHEASTERN STATES INCLUDING COASTAL
SC/NC...
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE EASTERN GREAT BASIN...
AMENDED FOR NC/SC AREA LATE TONIGHT
...SUMMARY...
Scattered severe storms are most likely across the Midwest and Ohio
Valley this afternoon into evening, with other severe storms along
the central Gulf Coast. Damaging winds, isolated weak tornadoes, and
hail will be possible in these areas.
...Midwest/Ohio Valley...
Isolated cells currently exist across central Indiana near a sharp
e-w oriented warm front. Locally backed surface winds along this
front may enhance tornado potential briefly for any storms
interacting with it, before they cross over into the cooler more
stable air. Otherwise, scattered storms continue to evolve along the
main cold front to the west, from southern IL into the lower MS
valley with wind and marginal hail threat. Tornado threat looks to
be reduced across much of KY and TN due to strong boundary-layer
mixing which both reduces moisture and truncates the lower parts of
the hodograph. For more information see MCD 379.
...Alabama into the Florida Panhandle...
A renewed cluster of cells has developed across southern AL in a
region of strong heating and where lapse rates are quite steep along
with long hodographs favorable for supercells and large hail. These
cells were ahead of an approaching MCS, which continues to surge
eastward across southern AL and into the western FL panhandle. While
hodographs are long, low-level shear is not particularly strong,
suggesting low end tornado threat. However, the orientation of the
deep-layer shear vectors are largely parallel to the approaching
line of storms, such that it remains possible that a brief/weak
tornado could still occur. Otherwise, hail would appear to be the
main threat. For more information see MCD 380.
...Coastal Eastern SC and southern NC Late Tonight...
Visible satellite imagery shows a boundary extending eastward from
southern SC with mid 60s dewpoints to the south of it. As the upper
trough approaches later tonight, this moisture will move farther
inland, an orient with an increasing low level jet with 30-40 kt at
850 mb. Several CAMs show the potential for isolated supercells to
form, perhaps over the water and move northward through early Friday
morning. Instability will not be strong but perhaps sufficient to
support a localized severe risk. Forecast soundings show favorable
hodographs for supercells, and perhaps a localized tornado threat.
Thus, have upgraded the tornado probabilities in this area.
..Jewell.. 03/30/2017
.PREV DISCUSSION... /ISSUED 1150 AM CDT Thu Mar 30 2017/
...Midwest and Ohio/Tennessee Valleys...
A closed mid/upper-level low will continue a slow general eastward
progression from the lower MO Valley and Ozarks toward the lower OH
River Valley through tonight. A related surface low will continue to
develop east-northeastward from east-central MO into central IL,
while a warm front advances northward across eastern IL and much of
IN/OH. Overall buoyancy will remain modest today and cloud cover has
remained semi-prevalent into midday across the warm sector. However,
some cloud breaks are noted near/just east of the MS River with
mid/upper 50s and some lower 60s F surface dewpoints otherwise
expected to expand northward in tandem with the warm front.
As gradual air mass destabilization occurs, storms may first
intensify across far eastern MO into southern IL just ahead of the
surface low and in concert with the aforementioned cloud breaks at
late morning. Additional warm sector or near-warm-frontal-related
development should also occur this afternoon into IN/OH this
afternoon, while other storms should form near the cold front across
KY/TN. While buoyancy will not be robust in most areas, long/largely
unidirectional hodographs, albeit with some near-1km AGL hodograph
curvature, will support a mixed mode including supercells and fast
northeastward-moving bows. Severe hail and damaging winds will be
possible, with a least some tornado risk as well, particularly near
the warm front where low-level SRH will be maximized.
...Gulf Coast States/lower MS River Valley...
12Z Upper-air data and contemporary surface observations/visible
satellite imagery show that considerable convective overturning has
occurred across parts of the region via an overnight/early morning
MCS. Ahead of a slow-moving convective cluster across southeast MS
and coastal eastern LA at late morning, the main severe risk should
be confined to far southeast MS into southern AL/FL panhandle and
eventually southwest GA. For additional short-term details, see
Mesoscale Discussion 377.
Farther west, in the wake of the early-morning MCS, some additional
development may occur near the north/south-oriented cold front this
afternoon. However, persistent cloud cover, modest
moisture/buoyancy, and limited near-frontal convergence all imply
that any near-frontal severe risk later this afternoon/evening
should remain limited across the lower MS Valley vicinity.
...Great Basin...
A band of showers and isolated storms is expected to form along a
strong cold front attendant to an amplifying shortwave trough.
Although buoyancy will be scant, well-mixed thermodynamic profiles
ahead of the front should support downward momentum transport of
robust flow aloft and may yield isolated severe wind gusts.
Proxima actualizacion: 01:00z.
A continuación, paso a dejarles las discusiones a mesoescala del día de hoy y los watches.
Mesoscale Discussion 0376
NWS Storm Prediction Center Norman OK
0134 AM CDT Thu Mar 30 2017
Areas affected...south central MS through southeast LA
Concerning...Tornado Watch 101...
Valid 300634Z - 300800Z
The severe weather threat for Tornado Watch 101 continues.
SUMMARY...Tornado risk continues to trend downward as primary threat
has transitioned to isolated damaging wind across remaining portion
of tornado watch 101. This watch will be allowed to expire at 08Z.
While some risk for mainly a few strong wind gusts may persist from
southeast LA into southern MS for an hour or two beyond 08Z, the
overall threat is expected to remain too marginal for another WW
issuance.
DISCUSSION...Broken squall line from southern MS into central
portions of coastal LA is moving east at 25-30 kt, while individual
storms embedded within the line move more rapidly northeast. A few
loosely organized storms persist within a portion of the line
including bowing segments across southern and south central MS. VWP
data show largely unidirectional wind profiles with modest size
low-level hodographs. Tendency will be for the low-level jet to
gradually shift north toward the TN Valley and away from the more
unstable portion of the warm sector into the early morning. While
threat for mostly a few strong to damaging wind gusts may persist
next 2-3 hours as storms continue through the marginally unstable
environment, overall threat appears too marginal for an additional
ww issuance.
..Dial.. 03/30/2017
Mesoscale Discussion 0377
NWS Storm Prediction Center Norman OK
1110 AM CDT Thu Mar 30 2017
Areas affected...coastal MS and AL
Concerning...Severe potential...Watch unlikely
Valid 301610Z - 301715Z
Probability of Watch Issuance...20 percent
SUMMARY...While wind damage is perhaps possible on a localized and
intermittent basis, the expected coverage and magnitude of this
possible risk will likely preclude a severe thunderstorm watch.
DISCUSSION...Visible satellite imagery shows a cumulus field over
the coastal counties of MS east into the FL Panhandle and surface
observations show temperatures have warmed into the upper 70s with
dewpoints near 70 degrees F. 500-mb upper air analysis this morning
shows the leading edge of more appreciable height falls (30-60 m per
12 hours) have overspread the coastal plain of MS/AL. Background
upward vertical motion associated with mid- to upper-level forcing
for ascent and 50+ kt flow at 500-mb are aiding in the maintenance
of the squall line over coastal MS southward to the Mouth of the MS
River. A 25-kt gust was measured at KASD at 1451z in association
with the squall line.
Analysis of the KMOB VAD data shows speed shear in the lowest 5-km
but the unidirectional southerly flow will probably prove
unfavorable for isolated 50-60 mph gusts and resultant widespread
wind damage given the north-south orientation of the convective
line. Nonetheless, the mature trailing stratiform convective line
will likely continue to move east across coastal MS/AL during the
next several hours. Localized/intermittent wind damage is possible,
but the weakness in mid-level lapse rates and aforementioned
concerns on the flow geometry imply the need for a severe
thunderstorm watch is low.
..Smith/Guyer.. 03/30/2017
Mesoscale Discussion 0378
NWS Storm Prediction Center Norman OK
1156 AM CDT Thu Mar 30 2017
Areas affected...central and southern IL...southeast MO...western KY
Concerning...Severe potential...Watch likely
Valid 301656Z - 301800Z
Probability of Watch Issuance...80 percent
SUMMARY...Storms will likely continue to develop and intensify near
the cold front. A wind-damage risk will likely develop this
afternoon. Hail is possible once stronger updrafts become sustained
and a tornado threat may focus near the warm front as storms
interact with the low-level vorticity rich environment.
DISCUSSION...Radar mosaic at 1645z shows a broken band of
thunderstorms across eastern and southeastern MO. Subjective
surface mesoanalysis places a warm front 30 miles north of STL
eastward to Indianapolis with a destabilizing warm sector across the
lower OH and middle MS Valleys with temperatures warming into the
upper 60s and dewpoints near 60 degrees F---yielding around 1000
J/kg SBCAPE per modified RAP soundings which is slightly greater
than objective analysis fields. Deep southerly flow strengthening
with height is resulting in 35-40 kt effective shear. Along the
warm frontal zone where the winds are relatively backed, an enlarged
hodograph yields around 150 m2/s2 0-1km SRH.
A mixed mode of both linear structures and cells are expected to
evolve within the convective band and move into IL/KY during the
next few hours. Hail may accompany the stronger cells. Wind damage
and isolated strong/severe gusts are possible with the cells and
linear segments as greater storm organization occurs this afternoon.
The conditional tornado risk may tend to focus near the warm front
and likely be predicated/dependent on a strong updraft interacting
favorably with the low-level vorticity rich environment.
..Smith/Guyer.. 03/30/2017
Mesoscale Discussion 0379
NWS Storm Prediction Center Norman OK
1255 PM CDT Thu Mar 30 2017
Areas affected...Central/Southern IN...far northern KY...western OH
Concerning...Severe potential...Watch likely
Valid 301755Z - 302000Z
Probability of Watch Issuance...80 percent
SUMMARY...Thunderstorm coverage will increase over the next hour or
so, with an attendant increase in the severe threat as well.
Damaging wind gusts and few tornadoes are possible and a watch will
likely be needed across portions of the area to cover the potential
threat.
DISCUSSION...Visible satellite imagery shows that cumulus clouds
have increased in the area of clearing across western IN over the
past half hour, suggesting both an increase in the forcing for
ascent as well as some destabilization. Wave structure to the new
clouds suggests the area remains stable but continued moisture
advection into the region should result in further destabilization
and an overall environment more supportive of surface-based storms.
Strong kinematic fields across the region have been sampled well by
area VAD profiles. Recent data from IND and ILX reported 0-6 km bulk
shear around 50 kt, which is more than sufficient for organized
updrafts. The somewhat limited instability and poor mid-level lapse
rates should limit hail production within these organized updrafts
but damaging wind gusts and a few tornadoes are still possible. The
tornado threat will be locally higher in those areas where the
surface winds remain backed, especially near the warm front. Given
this potential threat, a watch will likely be needed across portions
of the region this afternoon and evening.
..Mosier/Guyer.. 03/30/2017
Mesoscale Discussion 0380
NWS Storm Prediction Center Norman OK
0144 PM CDT Thu Mar 30 2017
Areas affected...Southern AL...western FL Panhandle
Concerning...Severe potential...Watch possible
Valid 301844Z - 301945Z
Probability of Watch Issuance...40 percent
SUMMARY...Isolated wind damage and hail is possible across southern
AL for the next few hours. Isolated damaging wind gust/tornado
threat is also possible ahead of the line across the western FL
panhandle.
DISCUSSION...Thunderstorm coverage has increased over the past hour
across southern AL, with several of these storms exhibiting
supercellular characteristics, particularly the storm which
developed over Escambia county (now in Butler county). This increase
in activity appears to be associated with the arrival of better low
to mid-level moisture and possibly an increase in large-scale
forcing for ascent as the upper level jet streak approaches the
region. The airmass across the region is currently moderately
unstable and the shear is expected to gradually increase over the
next few hours and mid-level flow increases. The close proximity of
much of this development suggests a mixed storm mode with
clusters/small bowing segments likely dominating. As a result, the
primary severe threat will likely result from storm mergers, at
least over the next few hours. Some hail and damaging wind gusts are
possible.
Farther south, the ongoing line of storms currently moving through
southern AL will continue eastward into the western FL panhandle
during the next hour so. Surface winds ahead of the line aren't
particularly strong but the more southeasterly character of these
winds coupled with a moist low-level airmass will support an
isolated damaging wind gust/tornado threat.
..Mosier/Guyer.. 03/30/2017
Mesoscale Discussion 0381
NWS Storm Prediction Center Norman OK
0327 PM CDT Thu Mar 30 2017
Areas affected...western KY...southern and east-central
IL...southwest into central IN...west-central OH
Concerning...Severe Thunderstorm Watch 103...104...
Valid 302027Z - 302100Z
The severe weather threat for Severe Thunderstorm Watch 103, 104
continues.
SUMMARY...Isolated marginally severe hail and strong to locally
severe gusts are possible this afternoon with the stronger storms.
A low risk for a tornado will likely focus over central and
east-central Indiana within tornado watch 104.
DISCUSSION...Radar mosaic shows a broken band of line segments and
cells from north to south from central IL into western TN. Cellular
storms continue to develop ahead of the band in the free warm sector
across the lower Wabash Valley and into central Indiana and
west-central OH. A warm front is slowly advancing northward across
central Indiana and west-central OH and is evident by temperatures
warming into the middle 60s from the upper 50s along the I-69
corridor northeast of Indianapolis. Easterly low-level flow is
being maintained immediately north of I-70 in central Indiana and OH
and is resulting in enlarged hodographs which may bolster a narrow
north-south corridor for weak supercell tornado potential.
Elsewhere away from the warm front, tornado potential appears
significantly limited as both low-level shear and surface
temperature-dewpoint spreads become less favorable for low-level
mesocyclones. However, warmer temperatures over the lower Wabash
Valley and eastward across south-central Indiana have resulted in
steepened 0-3 km lapse rates. Isolated damaging winds via
strong/locally severe gusts and marginally severe hail with the more
intense updrafts will likely be the main hazards with this activity
as it moves eastward across the lower Wabash Valley and into
south-central Indiana over the next 2-3 hours.
..Smith.. 03/30/2017
Mesoscale Discussion 0382
NWS Storm Prediction Center Norman OK
0433 PM CDT Thu Mar 30 2017
Areas affected...Western/central FL Panhandle...Far southeast
AL...Far southwest GA
Concerning...Severe potential...Watch possible
Valid 302133Z - 302300Z
Probability of Watch Issuance...40 percent
SUMMARY...Convective line approaching the region may pose a risk for
damaging wind gusts and a tornado or two. Trends across the region
will be monitored for possible watch issuance.
DISCUSSION...Well-developed convective line extending from far
southern AL into the northeast Gulf of Mexico is expected to
continue eastward/northeastward over the next several hours. Current
storm motion estimate for this line is northeastward (230-240
degrees) at 40 kt, which brings it near VPS around 22Z and to ECP
around 23Z. The airmass downstream of the line across the
west/central FL Panhandle and southeast AL/southwest GA is
characterized by temperatures in the mid 70s to low 80s, dewpoints
in mid 50s to mid 60s, and modest instability. Mesoanalysis
estimates the MLCAPE is currently around 500 J/kg. Low-level
southeasterly flow ahead of the line will help advect better
low-level moisture into the region, resulting in a modest increase
in instability just ahead of the line. This southeasterly low-level
flow will also contribute to better low-level shear, resulting in a
non-zero tornado threat, particularly given the anticipated
moistening of the airmass. Additionally, some forward propagation of
the line may result, contributing to increased threat for damaging
wind gusts. However, coverage of these severe events is currently
expected to be isolated, owing primarily the limited extent of the
better low-level moisture and the resulting less-favorable
thermodynamics inland from the coastal areas. Even so, the
well-developed nature of the approaching line bears watching and
trends across the region will be monitored closely for potential
watch issuance.
..Mosier/Edwards.. 03/30/2017
Mesoscale Discussion 0383
NWS Storm Prediction Center Norman OK
0540 PM CDT Thu Mar 30 2017
Areas affected...Portions of the Ohio Valley southward to
western/middle Tennessee
Concerning...Severe Thunderstorm Watch 103...
Valid 302240Z - 302345Z
The severe weather threat for Severe Thunderstorm Watch 103
continues.
SUMMARY...A broken band of thunderstorms will push eastward out of
the current severe thunderstorm watch this evening. While a marginal
damaging-wind risk may persist downstream of this watch,
thunderstorms should remain disorganized enough to preclude new
watch issuance.
DISCUSSION...Strong to briefly severe thunderstorms across portions
of the Ohio Valley southward to western Tennessee are progressing
eastward early this evening. While relatively strong southerly
uni-directional flow aloft and mixed low-level profiles may favor an
isolated damaging-wind threat through mid evening, convection should
remain relatively disorganized. This expectation is based on the
observation of veered near-surface flow noted in regional
observations and VWP data ahead of the line, as well as the narrow
buoyancy observed in the 20Z OHX sounding and various forecast
soundings. Additionally, efficient diabatic cooling will reduce
surface-based buoyancy through this evening. In turn, updraft
accelerations should suffer from weak low-level convergence and
considerable dry-air entrainment, likely precluding greater
convective organization and the need for a downstream watch.
..Picca.. 03/30/2017
Mesoscale Discussion 0384
NWS Storm Prediction Center Norman OK
0605 PM CDT Thu Mar 30 2017
Areas affected...Portions of Indiana and Ohio
Concerning...Tornado Watch 104...
Valid 302305Z - 310000Z
The severe weather threat for Tornado Watch 104 continues.
SUMMARY...An occasional damaging-wind risk will exist across
portions of southern/central Indiana over the next couple of hours
before diminishing this evening. A low-end tornado threat may also
persist in the near term close to the warm front across central
Indiana and Ohio.
DISCUSSION...A broken band of thunderstorms continues east across
central/southern Indiana this evening, aided by downstream
propagation within a relatively dry/well-mixed low-level
environment. This thermodynamic profile, combined with ample
uni-directional southwesterly flow, will maintain some damaging-wind
risk with small bowing segments through the early/mid evening hours.
However, due to the dry near-surface profile, diabatic cooling
should quickly render a stabilizing boundary layer, reducing the
threat for gusty/damaging winds.
Farther northeast, a very narrow corridor exists for low-end tornado
potential at the warm front. Here, backed surface flow yields more
notable veering with height, which may briefly yield low-level
mesocyclones and a quick uptick in tornadic potential. However,
similar to the damaging-wind risk, this threat should diminish
further over the next few hours.
Lastly, a gradual increase in large-scale ascent over Ohio has
yielded a few strong/briefly severe cells rooted above the surface.
Despite relatively narrow buoyancy profiles, strong effective shear
may continue to be sufficient for isolated instances of marginally
severe hail this evening. However, due to the low-end nature of the
threat, watch issuance is not expected.
..Picca.. 03/30/2017
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 103
NWS Storm Prediction Center Norman OK
1230 PM CDT Thu Mar 30 2017
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Central and southern Illinois
Western Kentucky
Far eastern Missouri
* Effective this Thursday afternoon and evening from 1230 PM
until 800 PM CDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Isolated very large hail events to 2 inches in diameter possible
A tornado or two possible
SUMMARY...Strong to severe thunderstorms will continue to develop
and intensify as they race northeastward from far eastern Missouri
into central/southern Illinois and western Kentucky. A marginally
moist and unstable environment and ample vertical shear will support
a wind damage risk along with some potential for hail and possibly a
brief tornado or two (mainly across Illinois portions of the Watch).
The severe thunderstorm watch area is approximately along and 60
statute miles east and west of a line from 30 miles north northwest
of Decatur IL to 35 miles south of Paducah KY. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU3).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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
tornadoes.
&&
AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 450. Mean storm motion vector
22035.
...Guyer
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 104
NWS Storm Prediction Center Norman OK
305 PM EDT Thu Mar 30 2017
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Central and southern Indiana
Western Ohio
* Effective this Thursday afternoon and evening from 305 PM until
1000 PM EDT.
* Primary threats include...
A few tornadoes possible
Scattered damaging wind gusts to 70 mph possible
Isolated very large hail events to 2 inches in diameter possible
SUMMARY...The air mass will continue to gradually destabilize along
and south of a northward-moving warm front across Indiana and
western Ohio. Aside from a damaging wind/some hail risk, moderately
strong low-level shear will support the possibility of tornadoes,
particularly near the warm front.
The tornado watch area is approximately along and 55 statute miles
north and south of a line from 10 miles west northwest of Terre
Haute IN to 35 miles north of Dayton OH. For a complete depiction of
the watch see the associated watch outline update (WOUS64 KWNS
WOU4).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and 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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 103...
AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean
storm motion vector 23035.
...Guyer
