Skip Navigation Links weather.gov 
NOAA logo-Select to go to the NOAA homepage NOAA's National Weather Service   Select to go to the NWS homepage
Storm Prediction Center
navigation bar left  
  navigation bar end cap


 
USA.gov is the U.S. Government's official Web portal to all Federal, state and local government Web resources and services.

    Day 2 Outlook >
Jul 30, 2015 0600 UTC Day 1 Convective Outlook
Updated: Thu Jul 30 06:00:05 UTC 2015 (Print Version | 20150730 1200Z Day 1 shapefile | 20150730 1200Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Tornado Wind Hail
 Population  Cities/Towns  CWAs  Interstates  Counties  ARTCC  FEMA Regions

 Forecast Discussion
   SPC AC 300600

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0100 AM CDT THU JUL 30 2015

   VALID 301200Z - 311200Z

   ...THERE IS A MRGL RISK OF SVR TSTMS FROM NEW ENGLAND TO PART OF THE
   MID-ATLANTIC STATES...

   ...THERE IS A MRGL RISK OF SVR TSTMS ACROSS THE SOUTHEAST AND
   CENTRAL GULF COAST STATES...

   ...SUMMARY...
   ISOLATED STRONG TO MARGINALLY SEVERE THUNDERSTORMS WILL BE POSSIBLE
   ACROSS THE NORTHEAST INTO THE MID-ATLANTIC STATES THIS
   AFTERNOON...WITH A SIMILAR SEVERE THREAT FROM THE SOUTHEAST STATES
   TO THE LOWER MISSISSIPPI VALLEY.

   ...SYNOPSIS...
   A CLOSED LOW...CURRENTLY MOVING TO THE NORTHEAST ACROSS NORTHERN
   ONTARIO PER WATER VAPOR IMAGERY...WILL BECOME STATIONARY THIS
   FORECAST PERIOD ACROSS HUDSON BAY AS IT DEEPENS AND AMPLIFIES.  THIS
   EVOLUTION WILL OCCUR AS AN UPPER RIDGE CENTERED OVER THE
   SOUTH-CENTRAL STATES SHIFTS WEST TO THE SOUTHERN HIGH PLAINS.  THE
   CYCLONIC-FLOW REGIME WITHIN THE SOUTHERN PERIPHERY OF THE HUDSON BAY
   LOW WILL ENCOMPASS THE UPPER MS TO UPPER OH VALLEYS INTO THE
   NORTHEAST STATES.  A SERIES OF MIDLEVEL SHORTWAVE TROUGHS EMBEDDED
   WITHIN THIS FLOW REGIME WILL TRACK THROUGH THE GREAT LAKES TO THE
   NORTHEAST...WHILE HEIGHT FALLS ATTENDANT TO THESE TROUGHS AND THE
   ENLARGEMENT OF THE HUDSON BAY LOW AID IN SHIFTING AN UPPER RIDGE
   EAST OF THE NORTHEAST STATES.  AT THE SURFACE...A COLD FRONT SHOULD
   EXTEND FROM WESTERN NY/PA THROUGH EASTERN TN...AND THEN WESTWARD
   THROUGH SOUTHERN AR TO THE RED RIVER VALLEY AT 12Z TODAY.  THIS
   FRONT WILL ADVANCE EAST THROUGH THE EASTERN STATES...WHILE THE
   TRAILING PORTION MOVES SOUTHWARD THROUGH THE CENTRAL GULF COAST
   STATES...LOWER MS VALLEY AND INTO CENTRAL TX. 

   ...NEW ENGLAND TO PARTS OF THE MID-ATLANTIC STATES...
   SHOWERS AND A FEW EMBEDDED TSTMS SHOULD BE ONGOING ALONG THE COLD
   FRONT AT THE START OF THE FORECAST PERIOD FROM WRN NY/PA TO THE
   CENTRAL APPALACHIANS.  SURFACE HEATING MAY BE LIMITED THROUGH THE
   DAY AHEAD OF THE COLD FRONT AND MIDLEVEL LAPSE RATES SHOULD BE WEAK.
   DESPITE THESE FACTORS...A MOISTENING WARM SECTOR AIR MASS FROM SOUTH
   TO NORTH SHOULD RESULT IN MODERATE INSTABILITY IN THE MID-ATLANTIC
   STATES...WHILE INSTABILITY IS FORECAST TO BE WEAKER WITH NORTHWARD
   EXTENT.  MODEST HEIGHT FALLS /30-50 METERS AT 500-MB PER 12 HR/
   ACROSS THE NORTHEAST STATES WITH THE APPROACH OF A LEAD SHORTWAVE
   TROUGH AND UPLIFT ALONG THE COLD FRONT SHOULD PROVE FAVORABLE FOR
   SCATTERED TSTM DEVELOPMENT INTO THE AFTERNOON.

   ALTHOUGH BULK SHEAR WILL BE STRONGER ACROSS NY INTO NEW
   ENGLAND...GIVEN STRENGTHENING WEST-SOUTHWESTERLY 500-MB WINDS TO 40
   KT...WEAKER INSTABILITY WITH NORTHWARD EXTENT PRECLUDES THE
   INTRODUCTION OF HIGHER SEVERE PROBABILITIES...MAINTAINING THE
   MARGINAL SEVERE RISK.  FARTHER SOUTH INTO EASTERN PA/NJ TO MD/VA...
   INSTABILITY WILL BE STRONGER...THOUGH WEAKER FORCING FOR ASCENT AND
   WEAKER BULK SHEAR SHOULD LIMIT STORM ORGANIZATION.  GIVEN THE DEGREE
   OF DESTABILIZATION...A FEW STRONGER WIND GUSTS CANNOT BE RULED OUT
   WITH SOUTHERN EXTENT...RESULTING IN THIS REGION BEING INCLUDED IN A
   MARGINAL SEVERE RISK FOR LOCALLY STRONG WIND GUSTS.

   ...SOUTHEAST STATES TO LOUISIANA...
   STRONG SURFACE HEATING WITHIN A MOIST ENVIRONMENT /PRECIPITABLE
   WATER OF 1.75 TO AROUND 2 INCHES/ WILL RESULT IN MODERATELY STRONG
   INSTABILITY WITH MLCAPE RANGING FROM 1500-2500 J/KG THIS AFTERNOON. 
   DESPITE WEAK LARGE-SCALE FORCING FOR ASCENT ACROSS THESE STATES...
   STORM DEVELOPMENT IS EXPECTED ALONG THE SOUTHWARD-MOVING COLD
   FRONT...LEE TROUGH FROM SC TO SOUTHERN GA...AND SEA BREEZE
   BOUNDARIES.  THE DEGREE OF INSTABILITY COMBINED WITH STEEPENING
   SURFACE TO 3-KM LAPSE RATES WILL RESULT IN A FEW STRONG/DAMAGING
   WIND GUSTS THIS AFTERNOON INTO THE EARLY EVENING.

   ...SOUTHWEST STATES TO PART OF THE SOUTHERN PLAINS...
   TSTMS ARE EXPECTED AGAIN FOR MUCH OF THIS FORECAST FROM PARTS OF
   EASTERN AZ THROUGH NM WHERE THE GREATEST STORM COVERAGE IS EXPECTED
   WITHIN A PLUME OF MOISTURE PER WATER VAPOR IMAGERY.  MEANWHILE...
   MORE OF A DIURNAL-TSTM THREAT WILL EXIST EASTWARD INTO SOUTHERN KS
   AND OKLAHOMA AND ALSO WESTWARD INTO PARTS OF SOUTHERN AND CENTRAL
   CA.  WEAK INSTABILITY ACROSS THESE AREAS IS EXPECTED TO PRECLUDE A
   SEVERE WEATHER THREAT.

   ..PETERS/MARSH.. 07/30/2015

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z

        
Top/Latest Day 2 Outlook/Today's Outlooks/Forecast Products/Home
Weather Topics:
Watches, Mesoscale Discussions, Outlooks, Fire Weather, All Products, Contact Us

NOAA / National Weather Service
National Centers for Environmental Prediction
Storm Prediction Center
120 David L. Boren Blvd.
Norman, OK 73072 U.S.A.
spc.feedback@noaa.gov
Page last modified: July 30, 2015
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities