U.S. Severe Weather Forecast (Конвекција-преглед)


acus01 kwns 230602 
Storm Prediction Center ac 230600 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0100 am CDT Fri Jun 23 2017 

Valid 231200z - 241200z 

..there is a slight risk of severe thunderstorms across parts of 
the central Gulf Coast states...Tennessee Valley...Ohio Valley and 
southern to central Appalachians... 

..there is a marginal risk of severe thunderstorms outside of the 
slight risk area in parts of the central Gulf Coast 
states...Tennessee Valley...Ohio Valley...southern to central 
Appalachians into the northeast... 

..there is a marginal risk of severe thunderstorms across parts of 
the Southern Plains... 

Thunderstorms associated with a tornado, wind damage and isolated 
large hail threat will be possible this afternoon from parts of the 
central Gulf Coast states northeastward into the central 
Appalachians. Marginally severe storms with strong wind gusts and 
hail will also be possible in the northeast and Southern Plains. 

..central Gulf Coast states/Tennessee Valley/southern and central 
the National Hurricane Center is forecasting the remnants of Cindy 
to move north-northeastward across the Tennessee and Ohio valleys 
today. Scattered thunderstorms will be mostly concentrated on the 
eastern side of the system where low-level flow is forecast to be 
strongest. The latest model guidance shows a 40 to 50 kt jet which 
is forecast move across middle Tennessee into southern Kentucky this 
afternoon. This will create favorable low-level shear conditions for 
rotating storms and a few tornadoes will be possible. Wind damage 
may also occur as low-level lapse rates become steep. The greatest 
severe threat should be from northern Alabama north-northeastward 
into middle Tennessee, central Kentucky and southern Ohio along the 
corridor of strongest instability. 

West-southwesterly mid-level flow will be in place across the 
northeast today as a cold front advances eastward across the lower 
Great Lakes. A corridor of low-level moisture is forecast ahead of 
the front where surface dewpoints should be in the mid 60s to near 
70 f. In response, a couple pockets of moderate instability will be 
possible by afternoon ahead of the front. Model forecasts develop 
scattered thunderstorms along the front and spread convection 
eastward across the region during the afternoon. Forecast soundings 
ahead of the front from Pittsburgh, PA to the Hudson Valley show 
unidirectional wind profiles above the boundary layer with 0-6 km 
shear forecast to be in the 30 to 40 kt range. This could be enough 
for marginally severe multicells. Line segments that can develop and 
persist may have potential to produce strong wind gusts during the 
mid to late afternoon. 

..Southern Plains... 
Northwest mid-level flow will be in place across the Southern Plains 
today as a cold front advances southward across the region. By 
midday, the front is forecast to be located from southeast New 
Mexico eastward into the Low Rolling Plains. As surface heating 
takes place, isolated to scattered thunderstorm development will 
likely initiate along and just ahead of the front where the models 
develop a narrow corridor of moderate instability. In addition, 
forecast soundings on The Caprock of West Texas this afternoon show 
directional shear in the lower to mid-levels which will contribute 
to about 30 kt of deep-layer shear. This along with steep low-level 
lapse rates may be enough for a marginal wind damage threat. Hail 
could also occur with the stronger updrafts. 

.Broyles/Mosier.. 06/23/2017 


Mesoscale Discussion

acus11 kwns 230209 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 230209 

Mesoscale discussion 1129 
National Weather Service Storm Prediction Center Norman OK 
0909 PM CDT Thu Jun 22 2017 

Areas affected...Central/Northeast Iowa 

Concerning...severe potential...watch unlikely 

Valid 230209z - 230415z 

Probability of watch issuance...20 percent 

Summary...isolated hail and damaging wind gusts are possible with 
thunderstorms along the front as it moves across Iowa. A generally 
limited severe threat is anticipated and a watch is not anticipated, 
but convective trends will be monitored closely. 

Discussion...thunderstorms have developed over the past hour along 
the cold front extending from ccy (in northeast ia) southwestward to 
cbf (in southwest ia). Airmass ahead of this cold front is 
characterized by dewpoints in the low 70s, which, when combined with 
steep mid-level lapse rates (i.E. Around 7-7.5 deg c per km per the 
latest mesoanalysis), is supportive of moderate instability. 
Continued southeastward progress of the cold front into this airmass 
is expected to result in continued thunderstorm development along 
the cold front. This region is along the southern periphery of the 
stronger flow aloft but enough shear (i.E. Effective shear around 30 
kt) exists to support some updraft organization and a supercell or 
two, particularly across northern portions of the region where the 
shear is strongest. Hail is possible with these more organized 
storms. Farther south, a more multicellular Mode is anticipated with 
any hail likely a result of brief updraft intensification due to 
cell mergers. Some upscale growth into a more linear system is 
possible but the generally modest mid-level flow (and shear) are 
expected to preclude anything but occasionally damaging winds. As a 
result, a watch is not current expected but trends will be monitored 
for upscale growth and a resulting increase in the damaging wind 

.Mosier/Hart.. 06/23/2017 

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


Latitude...Lon 41529527 42659365 43299270 43409152 42879114 41369267 
41089468 41529527