Current SPC Activity Chart

Current Severe US Wx Maps

SPC Activity Chart
Hazard Thu (05/23) Fri (05/24) Sat (05/25) Sun (05/26) Mon (05/27) Tue (05/28) Wed (05/29) Thu (05/30)
Severe Moderate Slight Slight Severe Severe Severe No Area No Area
Fire Elevated No Critical No Area Critical Critical No Area No Area No Area

Forecast Discussion - Convective Outlook

   SPC AC 231945

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0245 PM CDT Thu May 23 2019

   Valid 232000Z - 241200Z

   ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS EASTERN TX
   PANHANDLE...

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROMT THE TX
   SOUTH PLAINS TO CENTRAL KS...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS CHESAPEAKE BAY
   REGION...

   ...SUMMARY...
   Severe storms with large hail, damaging wind and tornadoes will
   continue today over a part of the central and southern Plains and
   from the Ohio Valley into parts of the Mid-Atlantic.

   ...20z Outlook...

   A few changes have been made to the 1630z outlook.

   1) Focused higher severe probs ahead of maturing squall line over
   MD/VA.  Convection has recently increased in intensity across
   northern VA/MD. This activity has renewed along the leading edge of
   an old MCS carcass where low-level lapse rates have increased as
   temperatures warmed into the 80s. Damaging winds should be noted
   along this squall line as it progresses toward the lower Chesapeake
   Bay.

   2) Extended severe probs west along decaying outflow into northern
   KY. Early-day MCS that progressed across the OH Valley has forced an
   outflow boundary across northern KY. This boundary should serve as
   the focus for convection to spread east over the next few hours.

   3) Nudged 15% hail probs northwest across western KS. Scattered
   elevated convection is rapidly developing/spreading north across
   western KS. Hail is the primary risk and 15% severe probability has
   been adjusted accordingly to account for this evolution.

   ..Darrow.. 05/23/2019

   .PREV DISCUSSION... /ISSUED 1130 AM CDT Thu May 23 2019/

   ...TX/OK/KS...
   A large upper trough is present today over the western states, with
   a vigorous shortwave trough rotating northeastward into western NM. 
   The large-scale lift and midlevel height falls associated with this
   feature will overspread parts of the southern high Plains this
   afternoon.  Meanwhile, a very moist and unstable air mass has become
   established across much of the TX Panhandle, with dewpoints in the
   upper 60s over much of the area.  Visible satellite imagery suggest
   the potential for relatively strong afternoon heating over the
   region, setting the stage for intense thunderstorm development.

   Present indications are that elevated convection capable of large
   hail will remain possible along and north of the surface boundaries
   over the northern TX Panhandle, OK Panhandle and southwest KS. 
   These storms would primarily pose a hail risk through the day. 
   Please refer to MCD #751 for further details.

   Intense surface-based initiation is expected along the dryline over
   the western TX Panhandle by mid afternoon, with supercells likely. 
   These storms will track north-northeastward across the ENH and MDT
   risk areas, and will be capable of very large hail and strong
   tornadoes.  It is unclear how long the storms will maintain discrete
   supercell mode, with all model solutions tending toward quasi-linear
   modes during the evening as storms track into northwest OK and
   southern KS.  This will increase the risk of damaging winds.

   Over south-central KS, rapid recovery of the surface air mass will
   provide a favorable zone for thunderstorm development and
   maintenance this afternoon and evening.  A few supercells are
   possible with an inherent tornado/large hail threat.  But perhaps
   more likely are bowing structures capable of damaging winds.  This
   activity may persist much of the evening and spread eastward into
   parts of northwest MO before weakening.

   ...NY into Mid Atlantic Region...
   A fast moving line of thunderstorms is tracking across central PA,
   and extends southwestward into WV.  This line may intensify this
   afternoon as it approaches the east coast, with a risk of locally
   damaging wind gusts.  Please refer to MCD #750 for further details.

   In the wake of the first line, multiple lines and clusters of
   thunderstorms are expected to form across parts of western/central
   PA into northern WV.  Fast flow aloft and sufficient time to heat
   will result in a favorable environment for a few severe storms
   capable of damaging wind gusts and some hail.  These storms will
   track eastward and approach the east coast by dark.  While damaging
   winds are the main threat, an isolated tornado or two cannot be
   ruled out.

    

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z