U.S. Severe Weather Forecast (Previsión convectiva)

Hoy
Mañana
día tres

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acus01 kwns 231652 
swody1 
Storm Prediction Center ac 231651 


Day 1 convective outlook corr 1 
National Weather Service Storm Prediction Center Norman OK 
1151 am CDT Wed may 23 2018 


Valid 231630z - 241200z 


..there is a slight risk of severe thunderstorms over parts of the 
north-Central Plains... 


Corrected for thunder line 


... 
Isolated severe thunderstorms are possible this afternoon and 
evening across the High Plains, eastern portions of Virginia/North 
Carolina, and eastern Maine. 


..northern High Plains... 
Morning water vapor imagery shows a large upper trough over the 
western states, with an embedded shortwave trough lifting 
northeastward through The Four-Corners region. Lift ahead of this 
feature should overspread parts of Wyoming and southeast Montana this 
afternoon and evening, leading to scattered thunderstorm 
development. Strong daytime heating and surface dewpoints in the 
50s, coupled with steep mid level lapse rates and relatively cool 
temperatures aloft will yield afternoon MLCAPE values of 1000-1500 
j/kg and only a weak cap. This, combined with favorable deep-layer 
shear will promote rotating updrafts capable of large hail and 
damaging winds. As storms spread eastward into parts of South Dakota/NE, 
outflow mergers will likely increase the risk of damaging wind gusts 
through the evening. 


..southern High Plains... 
Another round of afternoon/evening thunderstorms are expected to 
affect eastern nm and West Texas. Visible satellite imagery confirms 
that considerable low-level moisture is in place over this area, and 
as the low-clouds burn off this afternoon, a strongly unstable air 
mass should develop. Despite the favorable thermodynamic setup, 
vertical shear profiles are quite weak and steering flow is 5-10 
knots. This will lead to rather disorganized thunderstorms capable 
of locally damaging wind gusts and hail. Through the evening, cam 
solutions suggest that outflows may organize as they spread into 
west TX, with an increased risk of gusty/damaging winds in the more 
intense cores. 


... 
A warm/humid air mass is present today over parts of southern Virginia and 
much of NC, leading to strong afternoon instability (mlcape values 
of around 1500 j/kg). Models are in good agreement that scattered 
thunderstorms will affect this region later this afternoon and 
evening. Forecast soundings suggest low-level wind fields will be 
quite weak with less than 10kt winds expected in the lowest 4-5km. 
This suggests that isolated cells may briefly produce downbursts, 
but the threat of a more organized severe event is rather low. 


... 
Scattered thunderstorms are expected to affect parts of ME as a 
shortwave trough and associated cold front moves through the area. 
Organized severe storms are not expected, but the strongest cells 
could produce locally gusty/damaging wind gusts - especially in the 
eastern parts of the state. 


.Hart.. 05/23/2018 


$$ 

Mesoscale Discussion


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acus11 kwns 231823 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 231823 
txz000-okz000-nmz000-231930- 


Mesoscale discussion 0498 
National Weather Service Storm Prediction Center Norman OK 
0123 PM CDT Wed may 23 2018 


Areas affected...eastern New Mexico...western Texas 
Panhandle...southwest Texas 


Concerning...severe potential...watch unlikely 


Valid 231823z - 231930z 


Probability of watch issuance...20 percent 


Summary...a severe hail and wind threat will exist this afternoon. A 
ww is not expected at this time, however convective trends will be 
monitored. 


Discussion...visible satellite imagery shows cumulus development 
along the the higher terrain of New Mexico southward into southwest 
Texas. Dewpoints of mid 50s to low 60s are generally in place across 
the discussion area with strong heating occurring, particularly in 
southwest Texas. Continued heating and destabilization is expected 
over the next few hours which will lead to MLCAPE values from 1500 
j/kg to 2500 j/kg. While buoyancy will be plentiful, shear will be 
the limiting factor on storm severity -- rap analysis shows only 
20-30 kts of deep-layer shear across the area. Nevertheless, a 
severe hail and wind threat will exist through the afternoon with 
the strongest storms. With time, storms should congeal and form a 
loosely organized line that will propagate eastward across the Texas 
Panhandle, potentially posing a wind threat. A ww is not expected do 
to lack of better deep-layer shear for organization, however 
convective trends will be monitored. 


.Wendt/Hart.. 05/23/2018 


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


Attention...WFO...lub...Ama...maf...abq...epz... 


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