Mar 1, 2017 1630 UTC Day 1 Convective Outlook
Updated: Wed Mar 1 16:28:24 UTC 2017 (20170301 1630Z Day 1 shapefile | 20170301 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Public Severe Weather Outlook

The SPC is forecasting ...Severe thunderstorms expected over parts of the northern Tennessee, southern Kentucky, and far western Virginia area this morning....   Please read the latest public statement about this event.  View What is a Watch? clip.

Categorical Graphic
20170301 1630 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 147,564 37,163,285 Philadelphia, PA...Baltimore, MD...Charlotte, NC...Washington, DC...Atlanta, GA...
SLIGHT 142,410 40,960,864 New York, NY...Virginia Beach, VA...Raleigh, NC...Newark, NJ...Norfolk, VA...
MARGINAL 234,093 31,236,161 Boston, MA...Nashville, TN...Pittsburgh, PA...Buffalo, NY...Baton Rouge, LA...
Probabilistic Tornado Graphic
20170301 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
10 % 33,726 7,860,757 Atlanta, GA...Birmingham, AL...Sandy Springs, GA...Tuscaloosa, AL...Roswell, GA...
5 % 138,876 35,505,035 Philadelphia, PA...Baltimore, MD...Charlotte, NC...Washington, DC...Greensboro, NC...
2 % 351,541 66,019,589 New York, NY...Boston, MA...Nashville, TN...Virginia Beach, VA...Raleigh, NC...
Probabilistic Damaging Wind Graphic
20170301 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
45 % 67,023 15,042,024 Baltimore, MD...Washington, DC...Greensboro, NC...Winston-Salem, NC...Richmond, VA...
30 % 63,404 16,638,309 Philadelphia, PA...Charlotte, NC...Durham, NC...Huntsville, AL...Chattanooga, TN...
15 % 159,456 46,439,667 New York, NY...Virginia Beach, VA...Atlanta, GA...Raleigh, NC...Newark, NJ...
5 % 234,261 31,265,382 Boston, MA...Nashville, TN...Pittsburgh, PA...Buffalo, NY...Baton Rouge, LA...
Probabilistic Large Hail Graphic
20170301 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
15 % 52,960 10,337,704 Atlanta, GA...Birmingham, AL...Huntsville, AL...Chattanooga, TN...Sandy Springs, GA...
5 % 227,719 36,514,485 Baltimore, MD...Charlotte, NC...Washington, DC...Virginia Beach, VA...Raleigh, NC...
   SPC AC 011628

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1028 AM CST Wed Mar 01 2017

   Valid 011630Z - 021200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM PORTIONS
   OF NORTHEAST MS...NORTHERN AL...AND SOUTHERN TN NORTHEASTWARD TO THE
   MID-ATLANTIC...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SURROUNDING THE
   ENHANCED FROM PARTS OF THE LOWER MS VALLEY TO SOUTHERN NEW
   ENGLAND...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SURROUNDING THE
   SLIGHT ACROSS PORTIONS OF THE EASTERN STATES...

   ...SUMMARY...
   Severe thunderstorms with damaging winds are expected from portions
   of the Southeast to the Mid Atlantic region and parts of southern
   New England. Damaging winds will be likely, and the risk for
   tornadoes will exist particularly from parts of northeast
   Mississippi to portions of north Georgia and vicinity.

   ...Portions of the Southeast to the Mid-Atlantic region and southern
   New England...

   An extensive belt of strong mid/high-level flow across the Southern
   and Eastern States will maintain strong deep shear over a moist and
   diurnally destabilizing warm sector across the area. A squall line
   from Middle TN toward the central Appalachians will likely spread
   across the adjacent Piedmont during the next several hours.
   Re-intensification of this activity is expected, owing to the
   presence of adequate moisture return (upper 50s to lower 60s
   dewpoints) amidst surface heating and relatively steep midlevel
   lapse rates. Swaths of damaging wind gusts will be likely as this
   activity spreads toward the coastal plain through the evening. A
   couple of tornadoes will be possible. Severe-wind probabilities have
   been increased eastward across the Piedmont area.

   More separated updrafts/discrete convection are evolving across
   parts of the lower MS Valley, at the southern end of a zone of
   stronger deep ascent. As this activity spreads eastward toward parts
   of the southern Appalachians and vicinity, it will intercept a
   relatively more moist boundary layer supporting stronger instability
   further aided by steep midlevel lapse rates (around 8.5 C/km in the
   700-500-mb layer per the 12Z Jackson sounding). With 250-350 m2/s2
   of effective SRH associated with modestly curved though long
   hodographs, tornado probabilities have been increased in this area.

   With northward extent across the East (i.e., toward southern New
   England and vicinity), weaker instability will exist owing to more
   widespread cloud coverage amidst an antecedent cooler/drier boundary
   layer. However, strong vertical shear profiles will support a
   conditional severe risk.

   Modest destabilization may take place around the upper Ohio Valley
   and eastern Great Lakes area amidst recycled moisture ahead of the
   primary cold front, perhaps supporting a band of strongly forced
   convection spreading eastward from the late afternoon through the
   evening. Locally damaging wind gusts may accompany this activity.

   ..Cohen.. 03/01/2017

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