ACUS01 KWNS 200040
SPC AC 200038
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0738 PM CDT Sun May 19 2019
Valid 200100Z - 201200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE GREAT LAKES...LOWER OHIO VALLEY...MID-ATLANTIC...CENTRAL TO
NORTHERN APPALACHIANS...WESTERN NEW ENGLAND AND SOUTHERN HIGH
Thunderstorms capable of damaging wind gusts and hail will continue
this evening across parts of the Great Lakes/Ohio Valley area and
Mid-Atlantic into western New England. Severe hail also may be
possible late tonight into the early morning over parts of the
southern High Plains.
...Great Lakes/Lower Ohio Valley...
The latest water vapor imagery shows a shortwave trough over the
Great Lakes region. At the surface, a 1000 mb low is located in
northwestern lower Michigan with a cold front extending southward
from the low into the lower Ohio and mid Mississippi Valleys. Ahead
of the front, a corridor of maximized low-level moisture is present
from western Kentucky north-northward into northwest Ohio and lower
Michigan. A couple line segments with embedded strong thunderstorms
are ongoing along the most axis. This activity will continue for a
couple more hours, moving into western Ohio and southeast lower
Michigan. Moderate deep-layer shear, evident on regional WSR-88D
VWPs will be sufficient for a wind damage threat with the stronger
cells within the lines...see MCD 0694.
...Mid-Atlantic/Central and Northern Appalachians/Western New
The latest water vapor imagery shows a shortwave trough in the Great
Lakes with a upper-level ridge over the Northeast. A corridor of
maximized low-level moisture is present in the wake of the
upper-level ridge from the Mid Atlantic northward into eastern New
York. The RAP is analyzing a pocket of moderate instability along
this corridor with MLCAPE values from 1000 to 2000 J/kg. Scattered
thunderstorms are ongoing to the west of the strongest instability.
The activity is located in an environment characterized by moderate
deep-layer shear and steep low-level lapse rates. This will be
favorable for isolated damaging wind gusts as the storms move
eastward into the stronger instability this evening. Isolated large
hail will also be possible with rotating cells.
...Far Southeast Arkansas/Northwest Mississippi/Far Northeast
Scattered thunderstorms are ongoing along a cold front from far
southeast Arkansas into far northwest Mississippi. The RAP is
analyzing a corridor of moderate instability just ahead of the
front. This combined with steep low-level lapse rates will enable
the stronger cells to produce marginally severe wind gusts. Hail
will also be possible...see MCD 0695.
...Southern High Plains...
An upper-level trough will dig southeastward toward northwestern
Mexico tonight as southwest mid-level flow becomes more firmly
established across the southern Plains. In response to the
approaching system, strong moisture advection will develop across
the southern Plains. A warm front will move northward into Oklahoma
and the Texas Panhandle with moderate instability in place south of
the front. Lift associated with the low-level jet and increasing
large-scale ascent should result in isolated to scattered
thunderstorm development from eastern New Mexico into west Texas
late tonight. Due to strong effective shear and steep mid-level
lapse rates, supercells with isolated large hail will be possible.