Mar 30, 2017 1630 UTC Day 1 Convective Outlook
Updated: Thu Mar 30 16:50:48 UTC 2017 (20170330 1630Z Day 1 shapefile | 20170330 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170330 1630 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 63,474 8,291,671 Indianapolis, IN...Louisville, KY...Evansville, IN...Clarksville, TN...Bloomington, IN...
SLIGHT 232,405 34,106,898 Columbus, OH...Nashville, TN...Atlanta, GA...St. Louis, MO...Cincinnati, OH...
MARGINAL 242,327 22,493,720 Memphis, TN...Charlotte, NC...New Orleans, LA...Cleveland, OH...Toledo, OH...
Probabilistic Tornado Graphic
20170330 1630 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 % 196,726 27,796,846 Indianapolis, IN...Columbus, OH...Nashville, TN...St. Louis, MO...Cincinnati, OH...
2 % 206,234 25,423,712 Memphis, TN...Charlotte, NC...New Orleans, LA...Atlanta, GA...Fort Wayne, IN...
Probabilistic Damaging Wind Graphic
20170330 1630 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
30 % 39,490 6,652,934 Indianapolis, IN...Louisville, KY...Evansville, IN...Bloomington, IN...Muncie, IN...
15 % 233,327 32,385,767 Columbus, OH...Nashville, TN...Atlanta, GA...St. Louis, MO...Cincinnati, OH...
5 % 248,987 21,701,495 Memphis, TN...Charlotte, NC...New Orleans, LA...Toledo, OH...Baton Rouge, LA...
Probabilistic Large Hail Graphic
20170330 1630 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
30 % 58,324 6,719,314 Indianapolis, IN...Evansville, IN...Clarksville, TN...Bloomington, IN...Muncie, IN...
15 % 165,096 28,673,196 Columbus, OH...Nashville, TN...Atlanta, GA...St. Louis, MO...Cincinnati, OH...
5 % 210,455 25,142,056 Memphis, TN...Charlotte, NC...New Orleans, LA...Cleveland, OH...Toledo, OH...
   SPC AC 301650

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1150 AM CDT Thu Mar 30 2017

   Valid 301630Z - 311200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE
   MIDWEST/OHIO VALLEY...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO
   VALLEY/MIDWEST AND GULF COAST/SOUTHEAST STATES...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO
   VALLEY/MIDWEST AND GULF COAST/SOUTHEAST STATES...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE GREAT
   BASIN...

   ...SUMMARY...
   Scattered severe storms are most likely across the Midwest and
   Tennessee Valley this afternoon into evening, with other severe
   storms along the central Gulf Coast. Damaging winds, a few
   tornadoes, and hail will be possible in these areas.

   ...Midwest and Ohio/Tennessee Valleys...
   A closed mid/upper-level low will continue a slow general eastward
   progression from the lower MO Valley and Ozarks toward the lower OH
   River Valley through tonight. A related surface low will continue to
   develop east-northeastward from east-central MO into central IL,
   while a warm front advances northward across eastern IL and much of
   IN/OH. Overall buoyancy will remain modest today and cloud cover has
   remained semi-prevalent into midday across the warm sector. However,
   some cloud breaks are noted near/just east of the MS River with
   mid/upper 50s and some lower 60s F surface dewpoints otherwise
   expected to expand northward in tandem with the warm front.

   As gradual air mass destabilization occurs, storms may first
   intensify across far eastern MO into southern IL just ahead of the
   surface low and in concert with the aforementioned cloud breaks at
   late morning. Additional warm sector or near-warm-frontal-related
   development should also occur this afternoon into IN/OH this
   afternoon, while other storms should form near the cold front across
   KY/TN. While buoyancy will not be robust in most areas, long/largely
   unidirectional hodographs, albeit with some near-1km AGL hodograph
   curvature, will support a mixed mode including supercells and fast
   northeastward-moving bows. Severe hail and damaging winds will be
   possible, with a least some tornado risk as well, particularly near
   the warm front where low-level SRH will be maximized.

   ...Gulf Coast States/lower MS River Valley...
   12Z Upper-air data and contemporary surface observations/visible
   satellite imagery show that considerable convective overturning has
   occurred across parts of the region via an overnight/early morning
   MCS. Ahead of a slow-moving convective cluster across southeast MS
   and coastal eastern LA at late morning, the main severe risk should
   be confined to far southeast MS into southern AL/FL panhandle and
   eventually southwest GA. For additional short-term details, see
   Mesoscale Discussion 377.

   Farther west, in the wake of the early-morning MCS, some additional
   development may occur near the north/south-oriented cold front this
   afternoon. However, persistent cloud cover, modest
   moisture/buoyancy, and limited near-frontal convergence all imply
   that any near-frontal severe risk later this afternoon/evening
   should remain limited across the lower MS Valley vicinity.

   ...Great Basin...
   A band of showers and isolated storms is expected to form along a
   strong cold front attendant to an amplifying shortwave trough.
   Although buoyancy will be scant, well-mixed thermodynamic profiles
   ahead of the front should support downward momentum transport of
   robust flow aloft and may yield isolated severe wind gusts.

   ..Guyer.. 03/30/2017

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