001
ACUS01 KWNS 171950
SWODY1
SPC AC 171948

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0248 PM CDT Fri May 17 2024

Valid 172000Z - 181200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHEAST...AND THE NORTHERN PLAINS...

...SUMMARY...
Severe thunderstorms may impact parts of the central into eastern
Gulf Coast States and portions of the northern Plains this afternoon
through tonight. A few tornadoes, scattered damaging winds, and hail
all appear possible over the central/eastern Gulf Coast area.

...20Z Update...
Greater (5%) tornado probabilities have been realigned/focused along
an outflow boundary extending from parts of southern AL into the FL
Panhandle/north FL and southern GA. Recent surface observations and
visible satellite imagery show heating is occurring on both sides of
this boundary. But, it has moved little over the past couple of
hours. Current expectations are for the overall severe threat to
increase through the rest of the afternoon along/near this boundary,
where low-level shear is maximized per recent VWPs from KEOX. A few
tornadoes may occur with any supercell or small bowing cluster that
spreads eastward through this evening, along with damaging winds and
large hail. See Mesoscale Discussion 815 for more details on the
short-term severe threat for this area.

No changes have been made to the Slight Risk across the northern
Plains. Reference Mesoscale Discussion 814 and recently issued
Severe Thunderstorm Watch 253 for more details.

..Gleason.. 05/17/2024

.PREV DISCUSSION... /ISSUED 1115 AM CDT Fri May 17 2024/

...Northern Plains...
Morning satellite imagery shows a fast-moving shortwave trough over
western MT.  This feature will track into the northern High Plains
by mid-afternoon, where strong heating and steep low-level lapse
rates will be present.  Low-level moisture will be limited with
dewpoints only in the mid 40s.  However, cool temperatures aloft and
steep mid-level lapse rates will aid in the development of scattered
showers and thunderstorms over eastern MT - spreading eastward
across the Dakotas during the evening.  High-based and fast-moving
clusters of storms capable of damaging wind gusts appear to be the
main concern.  These storms may move into northwest MN before
weakening.

...Gulf Coast and Southeast States...
Widespread showers and thunderstorms are ongoing this morning from
southern MS into southern AL/GA.  Decreasing cloud cover to the
south of the convection will aid in destabilization, with a general
intensification of thunderstorms by mid-afternoon.  Strong
deep-layer westerly winds aloft and sufficient CAPE will promote
occasional storm intensification with locally damaging wind gusts
being the main threat. Activity may spread as far east as southeast
GA this evening.

...South TX into Southern LA...
Water vapor imagery shows a pronounced southern-stream upper trough
over west TX/northern Mexico.  This feature and an associated
mid-level speed max are expected to aid in the development of
scattered afternoon thunderstorms over the mountains of northern
Mexico, tracking into south TX.  Widespread morning storms over
south TX have greatly stabilized the air mass in this region,
lending uncertainty to how numerous/intense these afternoon storms
may become.  Therefore will maintain MRGL risk and re-evaluate later
today.  Whatever activity evolves across TX will track across the
northwest Gulf and move into southern LA late tonight, with the
potential for damaging wind gusts.

$$