U.S. Severe Weather Forecast (Sääkatsaus)

Day Three

acus01 kwns 240554 
Storm Prediction Center ac 240553 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
1153 PM CST Wed Jan 23 2019 

Valid 241200z - 251200z 

..there is a marginal risk of severe thunderstorms over a portion 
of the Florida Peninsula and eastern North Carolina... 

Thunderstorms are likely across the Florida Peninsula later this 
morning, with a few strong to severe wind gusts and a brief tornado 
possible. A few strong storms with damaging wind the main threat 
will also be possible over eastern North Carolina later this 

..Florida Peninsula... 

A strong (50+ kt) southerly low-level jet will migrate through the 
Florida Peninsula this morning with Theta-E advection resulting in 65-67 
f dewpoints over much of central Florida by 12z. Despite this modest 
increase in low-level moisture, instability will remain marginal 
(generally below 800 j/kg) due to poor mid-level lapse rates and 
widespread clouds. A band of convection with embedded thunderstorms 
will persist along the warm conveyor belt through the peninsula 
during the morning. The kinematic environment accompanying a 
progressive upper trough moving through the southeast states will 
favor a few organized structures including embedded bowing segments 
and meso-vortices. However, tendency will be for the stronger 
forcing associated with the upper trough to move away from the Florida 
Peninsula later this morning. This along with the expected marginal 
thermodynamic environment lowers confidence in a more robust severe 
threat. Therefore will maintain the marginal risk category this 
update, mainly for isolated damaging wind and a tornado. 

..eastern North Carolina... 

A surface low will develop over the mid Atlantic states by the start 
of this period in association with the northeast-ejecting shortwave 
trough. The attendant intense (80+ kt) low level jet will develop 
through eastern NC and eastern Virginia resulting in the advection of low 
60s f near-surface dewpoints inland and modest destabilization of 
the surface layer, though widespread clouds and weak lapse rates 
should limit MLCAPE to below 500 j/kg. With the stronger forcing 
moving through the mid Atlantic region early in the period within a 
very favorable kinematic environment for organized storms, potential 
exists for a low-topped pre-frontal band of convection to intensify 
from eastern NC into eastern Virginia later this morning. This band of 
showers with a few embedded thunderstorms may pose some risk for 
mainly damaging wind gusts given 60+ kt just off the surface that 
could be transported downward within the stronger convective 
elements. Activity should move offshore by late morning. 

.Dial/squitieri.. 01/24/2019 


Mesoscale Discussion

acus11 kwns 240219 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 240218 

Mesoscale discussion 0050 
National Weather Service Storm Prediction Center Norman OK 
0818 PM CST Wed Jan 23 2019 

Areas affected...portions of the Florida Panhandle...far southeastern 
Alabama...and far southwestern Georgia 

Concerning...severe potential...watch unlikely 

Valid 240218z - 240415z 

Probability of watch issuance...5 percent 

Summary...a semi-organized line of thunderstorms will continue to 
pose an isolated strong to damaging wind threat for the next couple 
of hours before weakening as it moves eastward this evening. Watch 
issuance is not expected. 

Discussion...a wind gust to 50 kt was observed at klor in 
southeastern Alabama at 0118z as a line of thunderstorms moved through, 
with other surface observations showing wind gusts of generally 
30-45 kt across far southeastern Alabama and the western Florida Panhandle. A 
couple reports of tree damage have also been received across this 
region. 40-50 kt of effective bulk shear will support continued 
storm organization in the short term. But, instability wanes quickly 
with eastward extent in the Florida Panhandle and far southwestern Georgia as 
surface dewpoints likewise decrease from the mid 60s to upper 50s. 
The 00z sounding from tlh showed an inversion around 620 mb and very 
minimal instability, which will likely induce weakening of the 
ongoing line of thunderstorms as they move eastward through the 
remainder of the evening. Still, at least some potential for an 
isolated strong to damaging wind gust should persist for the next 
couple of hours, particularly near the coast in the Florida Panhandle 
where instability, although weak, is slightly greater than locations 
farther inland. A brief, line-embedded tornado can also not be 
completely ruled out given the very strong low-level shear noted on 
the kevx vwp. 

.Gleason/Edwards.. 01/24/2019 

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


Latitude...Lon 30118574 30618564 31218544 31898495 31888449 31268419 
29908431 29768448 29598487 29578515 29698539 29848540