Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1223 AM CDT Tue Oct 22 2019

Valid 221200Z - 231200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
CENTRAL/EASTERN NC AND FAR SOUTHEAST VA...

...SUMMARY...
Thunderstorms capable of locally damaging winds and a tornado or two
are possible across parts of central and eastern North Carolina into
the Tidewater region of Virginia this afternoon into the early
evening.

...Southeast into the Mid Atlantic...
A deep upper trough covering much of the central/eastern CONUS is
expected to progress slowly eastward today. While the primary
occluding cyclone is expected to move from the Upper Great Lakes
into Ontario, a secondary frontal wave is expected to move from
Upstate SC this morning into the mid Atlantic this evening and
southern New England overnight. As this occurs, relatively rich
low-level moisture is expected to stream northward over portions of
the central/eastern Carolinas into the Tidewater region in advance
of a eastward-moving cold front. 

While generally weak midlevel lapse rates will limit buoyancy across
the region, at least modest heating of an increasingly moist
environment may allow MLCAPE to rise into 500-1000 J/kg range from
southern VA into the eastern Carolinas, along and south of the track
of the aforementioned frontal wave. Intensification of ongoing
morning convection and/or renewed development during the afternoon
will result in some damaging wind potential, given relatively strong
low/midlevel flow. Locally enhanced low-level shear near the track
of the surface wave will support the potential for a tornado or two
as well.  

...MT into the western Dakotas...
A vigorous shortwave trough over British Columbia this morning is
forecast move southeastward through the period. This feature will
begin approaching MT by late afternoon, moving into portions of the
northern Plains tonight. Despite cool temperatures and limited
low-level moisture, relatively steep low/midlevel lapse rates may
allow very weak surface-based buoyancy to develop over
central/eastern MT late this afternoon, in advance of the shortwave.
Strong unidirectional west-northwesterly flow will favor some
potential for strong wind gusts with any convection that can
develop. At this time, concerns regarding magnitude of available
buoyancy preclude the introduction of any severe wind probabilities.

..Dean/Squitieri.. 10/22/2019

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1150 PM CDT Mon Oct 21 2019

Valid 231200Z - 241200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
The risk for severe thunderstorms appears negligible across the
U.S., Wednesday through Wednesday night.

...Discussion...
The center of a broad and deep, but slowly filling, cyclone is
forecast to continue to slowly migrate across northern Ontario into
Hudson Bay during this period.  As a modest secondary surface low
migrates from New England coastal areas through the St. Lawrence
Valley, before weakening, the trailing cold front appears likely to
progress east of the much of the Atlantic Seaboard, with the
exception of the central/southern Florida Peninsula, where it
probably will stall and weaken beneath mid-level subtropical
ridging.

To the west, amplified mid-level ridging over the mid-latitude
eastern Pacific may take on more of a positive tilt, building
east-northeastward into British Columbia and the Pacific Northwest. 
As this occurs, a downstream short wave trough, initially digging
across the northern U.S. Rockies, may gradually split.  While one
perturbation turns more sharply southward toward the southern
Rockies/High Plains, the other may pivot through the mid Missouri
Valley.  However, spread among the models, and within their
respective ensemble output, increases through the period concerning
these developments.

It does appear that cold surface ridging will build across the
northern Rockies and nose eastward and southward across much of the
northern and central Plains.  There may be a weak to modest
southerly return flow of moisture into the vicinity of a
strengthening frontal zone on the leading edge of the colder air,
across parts of the southern Plains Wednesday night.  As this
advects into a corridor of strengthening lift driven by lower/mid
tropospheric warm advection, this may be accompanied by sufficient
destabilization to support scattered weak thunderstorm activity
across parts of central into northeast Oklahoma and adjacent
portions of southeast Kansas, southwest Missouri and northwest
Arkansas.

...MAXIMUM RISK BY HAZARD...
Tornado:  <2%     - None
Wind:     <5%     - None
Hail:     <5%     - None

..Kerr.. 10/22/2019