U.S. Severe Weather Forecast (Previsión convectiva)

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. 

..20z update... 

..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. 

..northern/Central Plains... 
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. 

..mid-Atlantic states... 
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 
tornado risk. 

.Mosier.. 07/22/2018 

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 
more information. 


Mesoscale Discussion

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. 

.Hart.. 07/22/2018 

..please see www.Spc.NOAA.Gov for graphic product... 


Latitude...Lon 30428350 30018251 29358229 28728154 28488121 28358151 
29058285 29638365 30058475 30558534 31318533 31638472 
31068384 30428350