Sep 11, 2017 0100 UTC Day 1 Convective Outlook
Updated: Mon Sep 11 01:12:23 UTC 2017 (20170911 0100Z Day 1 shapefile | 20170911 0100Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170911 0100 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 14,619 5,412,097 Jacksonville, FL...Orlando, FL...Palm Bay, FL...Deltona, FL...Melbourne, FL...
MARGINAL 19,487 5,857,805 Tampa, FL...St. Petersburg, FL...Gainesville, FL...Port St. Lucie, FL...Clearwater, FL...
Probabilistic Tornado Graphic
20170911 0100 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 14,569 5,436,844 Jacksonville, FL...Orlando, FL...Palm Bay, FL...Deltona, FL...Melbourne, FL...
2 % 11,544 2,422,423 Gainesville, FL...Port St. Lucie, FL...Charleston, SC...West Palm Beach, FL...Lakeland, FL...
Probabilistic Damaging Wind Graphic
20170911 0100 UTC Day 1 Damaging Wind Probabilities Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 34,042 11,238,141 Jacksonville, FL...Tampa, FL...St. Petersburg, FL...Orlando, FL...Gainesville, FL...
Probabilistic Large Hail Graphic
20170911 0100 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
   SPC AC 110112

   Day 1 Convective Outlook CORR 1
   NWS Storm Prediction Center Norman OK
   0812 PM CDT Sun Sep 10 2017

   Valid 110100Z - 111200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TONIGHT ACROSS
   PARTS OF THE EAST CENTRAL FLORIDA PENINSULA INTO PORTIONS OF
   NORTHEASTERN FLORIDA...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS
   SURROUNDING AREAS OF FLORIDA AND ADJACENT SOUTH ATLANTIC COASTAL
   AREAS...

   CORRECTED GENERAL THUNDERSTORM LINE (VICINITY OF SOUTHERN
   CALIFORNIA)

   ...SUMMARY...
   Hurricane Irma will continue to impact much of Florida tonight. 
   Among the potential hazards, some risk for tornadoes will persist,
   mainly near coastal areas between Melbourne and Jacksonville.

   ...01Z Outlook Update...

   ...Southeast...
   Within a weak but amplified belt of westerlies emanating from the
   subtropical eastern Pacific, upper troughing is in the process of
   digging across and east of the lower Mississippi Valley vicinity,
   through the Gulf of Mexico.  As this continues tonight, it still
   appears probable that the slowly weakening circulation center of
   Irma will gradually turn north/northwestward, tracking from just
   inland across the west central Florida Peninsula, toward Florida's
   Nature Coast area.  As it does, the environment most supportive of a
   continuing risk for tornadoes will gradually shift north of the east
   central Florida Peninsula.  However, with the onset of at least some
   diurnal boundary layer cooling, widespread rain also continues to
   inhibit boundary layer destabilization inland of Atlantic coastal
   areas, and the extent of any appreciable risk for tornadoes inland
   of immediate east central/northeast Florida coastal areas is
   becoming more unclear.  North and west of the Jacksonville area,
   into Georgia and South Carolina coastal areas, as well as the
   Florida Panhandle, near-surface wind fields are expected to maintain
   a northerly component through at least the remainder of this period.
    Emanating from a drier, potentially cool environment associated
   with expansive surface ridging centered over the lower Great Lakes,
   this is expected to maintain generally stable conditions with low to
   negligible risk for tornadoes.

   ...Southern California...
   Large-scale forcing for ascent, northeast of an offshore closed low
   within the subtropical westerlies, coupled with orographic forcing,
   have contributed to scattered thunderstorm development across the
   Transverse Ranges, northeast through north of Los Angeles/Oxnard. 
   This activity should remain confined to the vicinity of the higher
   terrain, while developing west northwestward, before diminishing
   with the loss of daytime heating during the 02-04Z time frame. 
   While sizable sub-cloud temperature dew point spreads could support
   a localized potentially damaging wind gust or two, severe weather
   probabilities, in general, still appear below 5 percent coverage.

   ..Kerr.. 09/11/2017

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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z