Outlook (Main)

1. SPC - No watches are valid as of Thu Sep 23 00:16:02 UTC 2021

   No watches are valid as of Thu Sep 23 00:16:02 UTC 2021.

2. SPC - No MDs are in effect as of Thu Sep 23 00:16:02 UTC 2021

   No Mesoscale Discussions are in effect as of Thu Sep 23 00:16:02 UTC 2021.

3. SPC Sep 22, 2021 2000 UTC Day 1 Convective Outlook

   SPC 2000Z Day 1 Outlook
   

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0238 PM CDT Wed Sep 22 2021
   
   Valid 222000Z - 231200Z
   
   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
   EASTERN OHIO...WESTERN PENNSYLVANIA...AND NORTHERN WEST VIRGINIA...
   
   ...SUMMARY...
   The greatest potential for damaging to severe thunderstorm winds and
   a few tornadoes today will be over parts of Ohio, West Virginia and
   western Pennsylvania.
   
   ...20Z Update...
   
   ...Upper OH Valley...
   Recent surface analysis places a deepen low near the OH/WV/PA border
   intersection, along the leading edge of a cold front pushing
   eastward across the OH Valley. Overall instability remains modest
   ahead of the front, but still sufficient for updrafts deep enough to
   produce lightning. Additionally, the clearing across southwest PA
   has allowed temperatures to climb into the low 80s, fostering
   locally higher buoyancy in this region. Vertical shear remains
   strong and the threat for embedded bowing structures capable of
   damaging wind gusts and a tornado or two is expected to persist
   throughout the afternoon into the early evening. 
   
   ...VA and Carolinas...
   As mentioned in recently issued MCD #1776, a couple damaging gusts
   may accompany the stronger storms through the remainder of the
   afternoon. However, any severe threat is expected to isolated and/or
   brief given the limited vertical shear.
   
   ..Mosier.. 09/22/2021
   
   .PREV DISCUSSION... /ISSUED 1107 AM CDT Wed Sep 22 2021/
   
   ...Upper OH Valley...
   A deep upper trough is moving slowly eastward across parts of
   IL/IN/KY today, with an associated surface cold front extending from
   central OH southward into east TN and northern GA.  A pocket of
   partly cloudy conditions has developed ahead of the front from
   central WV into eastern OH and western PA.  Continued afternoon
   heating/destabilization will yield MLCAPE values of 1000-1500 J/kg. 
   A surface low along the front over OH will deepen today as it tracks
   into western PA.  Backing/strengthening low-level winds ahead of the
   low will enhance convergence and aid in the development of
   thunderstorms along the cold front.  Shear profiles will be rather
   strong, posing the risk of supercell and bowing structures capable
   of damaging winds and a few tornadoes.  Storms should weaken by
   early evening as they move into more stable air over central PA.
   
   ...VA and Carolinas...
   The aforementioned surface cold front will move across the mountains
   of western VA/NC this afternoon.  Warm and humid conditions ahead of
   the front will result in thunderstorm development.  Low and
   deep-layer wind fields in this region are weaker than farther north,
   suggesting storms will be less organized.  Nevertheless, isolated
   intense cells may develop, with locally damaging winds possible.
   
   

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4. SPC Day 2 Fire Weather Outlook

   SPC Day 2 Fire Weather Outlook
   

   Day 2 Fire Weather Outlook  
   NWS Storm Prediction Center Norman OK
   0255 PM CDT Wed Sep 22 2021
   
   Valid 231200Z - 241200Z
   
   Added an elevated area for the southern Plains. More widespread
   winds of 15 to 20 mph seem likely with relative humidity of 13 to 18
   percent. In addition, recent fuel guidance shows ERC values locally
   above the 90th percentile indicating pockets of critically dry fuels
   are likely present.
   
   ..Bentley.. 09/22/2021
   
   .PREV DISCUSSION... /ISSUED 0144 AM CDT Wed Sep 22 2021/
   
   ...Synopsis...
   Morning surface observations from the Canadian Prairies show weak
   surface pressure falls already occurring as a lee low begins to
   develop. This feature is expected to continue deepening today before
   shifting eastward Thursday, funneling cold air into the northern and
   central High Plains as a result. Breezy and dry conditions behind
   this cold front may support a low-end fire weather concern.
   Increasing southerly winds across the Southern Plains may likewise
   support elevated conditions, but the probability of sustained 15+
   mph winds appears too low for highlights at this time. 
   
   ...Central High Plains...
   Recent ensemble guidance shows reasonably high probabilities for
   15-20 mph winds immediately behind the dry cold front as it shifts
   southward along the High Plains. A combination of dry air advection
   and a weak downslope component will likely result in widespread RH
   reductions into the teens and low 20s. While elevated wind/RH
   combinations appear likely, rainfall over the past 72 hours has
   reduced fuel readiness for many locations. Dry conditions today may
   help cure fine fuels to a degree, and highlights may be introduced
   in subsequent outlooks if fuel conditions sufficiently deteriorate.
   
   ...Please see www.spc.noaa.gov/fire for graphic product...
   
   

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