Feb 28, 2017 1730 UTC Day 2 Convective Outlook
Updated: Tue Feb 28 17:30:55 UTC 2017 (20170228 1730Z Day 2 shapefile | 20170228 1730Z Day 2 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170228 1730 UTC Day 2 Outlook Graphic
Day 2 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 115,552 15,675,663 Columbus, OH...Nashville, TN...Cincinnati, OH...Lexington-Fayette, KY...Louisville, KY...
SLIGHT 335,412 88,598,503 New York, NY...Philadelphia, PA...Memphis, TN...Baltimore, MD...Charlotte, NC...
MARGINAL 192,863 27,126,222 Detroit, MI...Indianapolis, IN...Boston, MA...Toledo, OH...Buffalo, NY...
Probabilistic Graphic
20170228 1730 UTC Day Probabilitic Graphic
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
Day 2 Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
30 % 114,573 15,190,654 Columbus, OH...Nashville, TN...Cincinnati, OH...Lexington-Fayette, KY...Louisville, KY...
15 % 339,070 89,401,428 New York, NY...Philadelphia, PA...Memphis, TN...Baltimore, MD...Charlotte, NC...
5 % 191,154 26,793,859 Detroit, MI...Indianapolis, IN...Boston, MA...Toledo, OH...Buffalo, NY...
   SPC AC 281730

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1130 AM CST Tue Feb 28 2017

   Valid 011200Z - 021200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST
   MISSISSIPPI AND NORTHERN ALABAMA ACROSS PARTS OF
   TENNESSEE...KENTUCKY...SOUTHERN OHIO AND WEST VIRGINA...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SURROUNDING THE
   ENHANCED RISK FROM THE SOUTHEAST STATES INTO THE MID-ATLANTIC REGION
   AND SOUTHERN NEW ENGLAND...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SURROUNDING THE
   SLIGHT RISK....

   ...SUMMARY...
   Strong to severe thunderstorms will be possible from the lower
   Mississippi Valley northeastward across the Tennessee Valley and
   Appalachians, and northward into parts of the Mid-Atlantic states
   into southern New England.  Damaging winds are forecast to be the
   predominant severe hazard.  However, a few tornadoes will be
   possible, especially during the day, from the Tennessee Valley into
   the middle and upper Ohio Valley.

   ...Synopsis...
   An energetic progressive flow pattern is forecast to persist through
   Wednesday as the current full-latitude western US upper trough moves
   eastward into the Plains tonight and then lifts east-northeastward
   across the northeast states through Wednesday night.  Very strong
   winds aloft accompany this system with 100+ kt maxima at 500 mb and
   60-65 kt at 850 mb which will provide intense low-level and
   deep-layer vertical shear supportive of severe storms.

   At the surface, a low over southeast lower Michigan at the start of
   the period is expected to deepen as it moves across the lower Great
   Lakes during the day, reaching northern Maine by the end of the
   period.  A trailing cold front initially extending southwest from
   the low across the middle Mississippi Valley to the upper Texas
   coast will progress eastward and southeastward during the period,
   crossing the Appalachians by 00Z and moving offshore into the
   Atlantic between 06-09Z and extending across northern Florida into
   the eastern Gulf of Mexico by the end of the period.

   ...Tennessee Valley into the middle/upper Ohio Valley...
   Strong to severe storms are likely to be ongoing early in the period
   in association with several pre-frontal convective systems from
   parts of Ohio southwestward into parts of the mid-South region.  The
   mesoscale/near-storm environment west of the Appalachians is
   expected to be characterized by 60-65F surface dew points, MUCAPE
   ranging from 750 J/kg in Ohio to 1200 J/kg in the mid-South, and an
   expansive region of very strong vertical shear of 50-70 kt in the
   lowest 6 km AGL will support some rotating updrafts, especially if
   more discrete cells can be maintained.  Nevertheless, strongest
   storms will have potential to produce all severe hazards including a
   few tornadoes, especially during the daytime hours, as cells move
   rapidly eastward/northeastward along and ahead of the advancing cold
   front.

   ...East of the Appalachians from southern New York/New England into
   the Carolinas and Georgia... 
   Over the northern part of this area, several rounds of strong/severe
   storms may spread eastward across the region before the threat ends
   with passage of the cold front.  Farther south, the primary
   convective threat is expected to remain closer to the cold front
   where a line of storms is likely to develop and progress
   eastward/southeastward through the afternoon into the overnight
   hours.

   Low-level moisture is expected to gradually increase, especially
   from the Atlantic, with surface dew points of 60-65F from the
   Delmarva region southward, and 50-60F extending northward into
   southern parts of New York and New England.  The limited moisture
   will be offset to some extent by an plume of modestly steeper
   mid-level lapse rates spreading over the area, with MUCAPE of
   500-1000 J/kg possible over the area.  Strong winds aloft and
   associated vertical shear will enhance storm organization, with
   potential for some rotating updrafts and bowing  line segments to
   develop through the night.  Damaging wind gusts are expected to be
   primary severe threat, although a tornado cannot be ruled out given
   the large clockwise low-level hodograph structure indicated in
   forecast soundings.

   ..Weiss.. 02/28/2017

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   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0700Z