vendredi 25 avril 2014

Apr 25, 2014 0600 UTC Day 1 Convective Outlook,,,,,,,,,,,,http://www.spc.noaa.gov/products/outlook/day1otlk.html

DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1132 PM CDT THU APR 24 2014

   VALID 251200Z - 261200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF SOUTHEAST
   VIRGINIA AND NORTHEAST NORTH CAROLINA...

   ...SUMMARY...
   SCATTERED SEVERE THUNDERSTORMS ARE EXPECTED TO DEVELOP DURING THE
   AFTERNOON ACROSS PARTS OF SOUTHEAST VIRGINIA AND INTO EASTERN NORTH
   CAROLINA...WHERE HAIL AND LOCALLY DAMAGING WINDS WILL BE THE MAIN
   THREATS. WHILE THE OVERALL TORNADO THREAT WILL REMAIN LIMITED ACROSS
   THE REGION...A TORNADO OR TWO WILL BE POSSIBLE ACROSS FAR SOUTHEAST
   VIRGINIA INTO NORTHEAST NORTH CAROLINA.

   ...SYNOPSIS...
   A NEGATIVELY TILTED SHORTWAVE TROUGH OVER THE OHIO AND TENNESSEE
   VALLEYS THIS MORNING WILL SHIFT EASTWARD ACROSS THE APPALACHIANS
   DURING THE AFTERNOON BEFORE MOVING OFFSHORE AFTER 00Z/SATURDAY. AT
   THE SURFACE...WEAK LOW PRESSURE CENTERED OVER WESTERN OHIO WILL LIFT
   NORTHEAST ALONG THE LOWER GREAT LAKES...AND A TRAILING COLD FRONT
   EXTENDING SOUTHWARD FROM THE LOW WILL MOVE EWD ACROSS THE
   APPALACHIANS INTO THE VA/NC PIEDMONT BY 00Z SATURDAY.
   THUNDERSTORMS...SOME SEVERE...ARE EXPECTED TO DEVELOP AHEAD OF THIS
   FEATURE ACROSS SOUTHEAST VIRGINIA AND EASTERN NORTH CAROLINA.

   ELSEWHERE...WIDELY SCATTERED THUNDERSTORMS ARE POSSIBLE ALONG THE
   PACIFIC NORTHWEST COAST INTO THE NORTHERN ROCKIES AND GREAT BASIN AS
   AN UPPER TROUGH STRENGTHENS/AMPLIFIES ALONG THE WEST COAST DURING
   THE AFTERNOON...BEFORE MOVING INLAND OVERNIGHT.

   ...SOUTHEAST VIRGINIA AND EASTERN NORTH CAROLINA...

   WIDESPREAD SHOWERS AND THUNDERSTORMS WILL BE ONGOING ACROSS THE
   APPALACHIANS THIS MORNING AS UPPER LEVEL SHORTWAVE TROUGH TRACKS EWD
   TOWARD THE MID-ATLANTIC. A WARM FRONT WILL LIFT NORTHWARD ACROSS ERN
   NC TOWARD THE CHESAPEAKE WITH A WARM/MOIST AIRMASS SPREADING OVER
   THE PIEDMONT AND COASTAL PLAINS OF NC INTO SE VA. WEAK TO MODERATE
   DESTABILIZATION /LESS THAN 1800 J PER KG MUCAPE/ WILL OCCUR AS
   TEMPERATURES WARM INTO THE MID TO UPPER 70S F AND SFC DEW POINTS
   CLIMB INTO THE LOW...TO LOCALLY MID 60S F. MIDLEVEL LAPSE RATES WILL
   STEEPEN THROUGH THE AFTERNOON AS COOLING ALOFT OCCURS WITH THE
   APPROACH OF THE UPPER IMPULSE. STRONG SHEAR COINCIDENT WITH THE EXIT
   REGION OF THE MIDLEVEL JET WILL OVERSPREAD THE SLIGHT RISK AREA AND
   AID IN ORGANIZATION OF THUNDERSTORM UPDRAFTS. FORECAST SOUNDINGS
   INDICATE CYCLONICALLY CURVED...ALBEIT SMALL...LOW LEVEL HODOGRAPHS.
   THIS WILL MAINLY SUPPORT INSTANCES OF LARGE HAIL AND LOCALLY
   DAMAGING WINDS. HOWEVER...A TORNADO OR TWO IS POSSIBLE MAINLY ACROSS
   NE NC INTO EXTREME SE VA WHERE BACKED LOW LEVEL FLOW AND STRONGER
   PRE-FRONTAL CONVERGENCE IS EXPECTED TO BE MORE FAVORABLE. THE SEVERE
   THREAT SHOULD WANE QUICKLY WITH DIURNAL COOLING AND AS THE SYSTEM
   MOVES OFFSHORE.

Aucun commentaire:

Enregistrer un commentaire