Severe Storm Outlook Narrative (AC)
Issued by NWS

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14
950
ACUS02 KWNS 071720
SWODY2
SPC AC 071719

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1119 AM CST Fri Feb 07 2025

Valid 081200Z - 091200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Scattered thunderstorm development is possible across parts of the
Ohio Valley Saturday into Saturday night, but the risk for severe
weather appears negligible.

...Discussion...
Mid/upper flow is in the process of amplifying across the northern
mid-latitudes of the eastern Pacific into western North America, and
models continue to indicate further amplification into and through
this period.  This includes building mid-level ridging across the
northeastern Pacific through Alaska, and subsequent digging
downstream troughing across and to the lee of the Canadian and
northern U.S. Rockies.  Otherwise, the confluent downstream
westerlies are forecast to remain generally zonal across the
interior U.S. through offshore western Atlantic, between broad
ridging, centered over the subtropic latitudes of northern Mexico
into the western Atlantic, and a broad vortex, centered near the
northeastern Canadian Arctic latitudes.  At mid/upper levels, the
subtropical ridging may maintain considerable influence as far north
as the southern into central tier of the United States.

Within the confluent regime across the northern tier of the U.S., it
still appears that at least a couple of short wave perturbations
might loosely consolidate into larger-scale, but still
low-amplitude, troughing across the Great Lakes into Northeast by
late Saturday through Saturday night.  This is forecast to be
trailed by a similar perturbation accelerating from the Great Basin
into north central Great Plains.  Beneath and just to the south of
this regime, another cold surface ridge is likely to be in the
process of building to the lee of the northern Rockies by early
Saturday, reinforcing cold air already entrenched to the east of the
Rockies.  It still appears that the shallow southern periphery of
this cold air will initially be in the process of eroding beneath a
continuing south to southwesterly return flow across the Ozark
Plateau into Ohio Valley.  However, models indicate that associated
low-level warming and moistening will largely remain confined
beneath dry, warming layers farther aloft, as the reinforcing cold
intrusion progresses south (and reaches the Gulf Coast state by 12Z
Sunday).

...Ohio Valley...
A pre-frontal corridor of boundary-layer warming and moistening near
a developing frontal wave may contribute to weak potential
instability, coincident with strengthening lower/mid-tropospheric
wind fields, across the southern/eastern Kentucky vicinity by late
Saturday afternoon.  However, based on latest model output, it
remains unlikely that forcing for ascent within the warm sector will
be sufficient to overcome inhibition.

Weak elevated thunderstorm development still appears possible
Saturday through Saturday night, within an initial
lower/mid-tropospheric warm advection regime near/north of the Ohio
River into Allegheny Plateau and, later, near/south of the Ohio
River along the undercutting southward advancing cold front.

..Kerr.. 02/07/2025

$$