Severe Storm Outlook Narrative (AC)
Issued by NWS
ACUS11 KWNS 220006
SPC MCD 220005
Mesoscale Discussion 0097
NWS Storm Prediction Center Norman OK
0605 PM CST Sat Jan 21 2017
Areas affected...Southeast Louisiana/southern Mississippi and
Concerning...Tornado Watch 15...
Valid 220005Z - 220130Z
The severe weather threat for Tornado Watch 15 continues.
SUMMARY...Severe/tornado threat is expected to steadily increase
over the next few hours in/near Tornado Watch 15.
DISCUSSION...Latest radar loop shows scattered strong/severe storms
increasing from the northwest Louisiana vicinity southeast across
the New Orleans area, near a warm front arcing
northwest-to-southeast across this region. A moist/buoyant boundary
layer (dewpoints into the low 70s) continues to spread slowly
northward in conjunction with the advancing warm front, which should
remain a focus for continued convective development/increase over
the next several hours.
As the left exit region of a 100 kt mid-level jet streak spreads
eastward across the area and low-level winds likewise increase,
shear will favor intense/rotating updrafts. This in conjunction
with backed surface flow near/just north of the warm front will
enhance the overall environment with respect to severe risk --
including the possibility for strong/long-lived tornadoes. We will
continue to monitor northward progression of the warm front and
associated convective evolution, with an eye toward
future/additional tornado watch issuance north and east of WW 15
(into central Mississippi, central and southern Alabama, and
possibly parts of the Florida Panhandle).
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 31958937 31208801 29718820 29498974 30049197 30849270
32169205 32259082 31958937