- día tres
acus01 kwns 222000
Storm Prediction Center ac 221959
Day 1 convective outlook
National Weather Service Storm Prediction Center Norman OK
0259 PM CDT sun Jul 22 2018
Valid 222000z - 231200z
..there is a slight risk of severe thunderstorms over a portion of
the Gulf Coast states as well as the northern and Central Plains...
Severe storms, primarily capable of damaging winds and large hail,
will be possible across parts of the southeast and northern/Central
Plains this afternoon and evening. A few marginally severe storms
are also possible over a portion of the middle Atlantic region.
..Central Gulf Coast into Florida...
very moist and unstable airmass over the region will continue to
support a severe thunderstorm threat. Recent radar imagery shows the
outflow surging southward along the east-central Florida coast while
warm-air advection and resultant backbuilding persists farther
northwest towards the Florida Big Bend. Outflow-dominant character to the
southeastern portion of the this convective complex suggests a
somewhat diminished severe threat, although isolated damaging wind
gusts remain possible. Relatively higher threat exists across the
backbuilding portion of the cluster as storm interactions and new
updraft development increase the chances for water loading. Moist
inflow and somewhat stronger southeasterly winds will also support a
low tornado threat in this region.
Severe threat also continues across southern al, southwest GA, and
adjacent portions of the Florida Panhandle. In this area, a more discrete
storm Mode and stronger shear has lead to the development of several
supercells with the moist and unstable airmass supporting both left
and right splits. Discrete storm Mode and more updraft organization
has led to a greater threat for hail here than over areas farther
southeast. Upscale growth into a more coherent convective line which
then tracks across the central Florida Peninsula is possible. Subsidence
behind the ongoing storms as well as beneath the right exit region
of the upper jet will likely temper any additional development
across southern Alabama. Additional short-term details about this area
are available in mesoscale discussion 1136.
Overall scenario outlined in the previous discussion (appended
below) remains valid with no change needed to the outlook.
Additional short-term information is available in mesoscale discussion 1135.
Observational trends and recent guidance suggest the severe threat
across SC has dropped below 5% and the outlook was updated
accordingly. Elsewhere across the region, enhanced mid-level flow
supports occasional bowing line segments and the potential for
damaging wind gusts. Additionally, southeasterly surface winds
across eastern Virginia result in slightly stronger low-level shear
(sampled well by recent lwx and akq VAD wind profiles) and a low
Previous discussion... /issued 1130 am CDT sun Jul 22 2018/
..Gulf coastal area including Florida...
Numerous storms are in the process of developing within the weakly
capped, but moderately unstable environment across northern Florida.
These storms will be capable of producing mainly isolated damaging
wind. Additional storms are expected to develop/intensify farther
west along and south of a cold front across southern Alabama as well as
in association with sea breeze boundaries over the Florida Panhandle.
These storms will be embedded within 35-45 kt unidirectional
effective bulk shear within base of upper low circulation. Damaging
wind and large hail will be possible with both multicell and
supercell storm modes.
..northern through Central Plains region...
A shortwave trough will continue east through Saskatchewan and
Manitoba along the international border and eventually affecting
extreme northern ND. A cold front will accompany this feature
through the northern and Central Plains today and tonight. A
corridor of moderate instability is likely in pre-frontal warm
sector along with sufficient (35-45 kt) deep-layer shear for
supercells from ND into South Dakota. Storms will likely develop over the
Dakotas later this afternoon posing a risk for isolated large hail
and damaging wind gusts. Other storms might develop farther south
along the front across central NE by early evening where weaker
shear will promote multicells, but the thermodynamic environment
will support some threat for a few instances of damaging wind and
large hail. Other storms will form over the higher terrain of Colorado and
Wyoming and spread east into the High Plains this afternoon and evening
with a modest threat for damaging wind and hail.
..middle Atlantic region...
Some destabilization is likely in this region today and potential
will exist for storms to redevelop and interact with a weak warm
front as they lift north. Low-level hodographs in vicinity of this
boundary will support a modest risk for a few low-level
mesoscyclones and a brief tornado or two. Reference sels mesoscale discussion 1132 for
acus11 kwns 222005
sels mesoscale discussion
Storm Prediction Center mesoscale discussion 222005
Mesoscale discussion 1137
National Weather Service Storm Prediction Center Norman OK
0305 PM CDT sun Jul 22 2018
Areas affected...northern Florida...southwest Georgia
Concerning...Severe Thunderstorm Watch 303...
Valid 222005z - 222200z
The severe weather threat for Severe Thunderstorm Watch 303
Summary...the corridor of greatest threat for severe storms through
22z will be from southwest Georgia into north-central Florida.
Discussion...a large convective complex continues to affect
northeast FL, with strong to severe storms extending from Orange
County northwestward to near Gainesville. Westerly low level winds
are maximizing the convergence along the portion of the line from
Lake County northward, and this is where the strongest storms are
likely to continue for the next couple of hours. Farther east near
the East Coast, low level flow is parallel to the boundary and is
less likely to favor intense cells.
Farther west, severe severe storms are tracking out of southeast Alabama
and into southwest Georgia. These storms will pose a risk of large hail
and damaging wind gusts through the late afternoon as they move
southeastward at 25-30 knots.
..please see www.Spc.NOAA.Gov for graphic product...
Latitude...Lon 30428350 30018251 29358229 28728154 28488121 28358151
29058285 29638365 30058475 30558534 31318533 31638472