Jul 5, 2019 1730 UTC Day 2 Convective Outlook
Updated: Fri Jul 5 17:30:23 UTC 2019 (20190705 1730Z Day 2 shapefile | 20190705 1730Z Day 2 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20190705 1730 UTC Day 2 Outlook Graphic
Day 2 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 81,367 3,105,507 Manchester, NH...Nashua, NH...Greeley, CO...Portland, ME...Haverhill, MA...
MARGINAL 433,663 74,130,196 New York, NY...Philadelphia, PA...Columbus, OH...Baltimore, MD...Boston, MA...
Probabilistic Graphic
20190705 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
15 % 81,367 3,105,507 Manchester, NH...Nashua, NH...Greeley, CO...Portland, ME...Haverhill, MA...
5 % 433,708 74,129,855 New York, NY...Philadelphia, PA...Columbus, OH...Baltimore, MD...Boston, MA...
   SPC AC 051730

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1230 PM CDT Fri Jul 05 2019

   Valid 061200Z - 071200Z


   Isolated strong to severe storms may occur on Saturday across the
   northern/central Rockies into the adjacent High Plains, and over
   much of the Northeast into the Mid Atlantic and Ohio Valley,
   accompanied by some risk for large hail and potentially damaging
   wind gusts.

   ...Northeast into the Mid Atlantic and OH Valley...
   An upper trough/low will move eastward over Quebec and the Northeast
   on Saturday. At the surface, a cold front is expected to develop
   east-southeastward across the Northeast into parts of the Mid
   Atlantic and OH Valley through the period. The strongest mid-level
   flow is expected to generally remain in Canada, but some enhancement
   to mid/upper-level winds should occur across parts of New England by
   Saturday afternoon. A moist low-level airmass, characterized by
   upper 60s to lower 70s surface dewpoints, should exist ahead of the
   surface front. As diurnal heating warms surface temperatures into
   the lower to mid 80s, destabilization of the warm sector will occur.
   MLCAPE in the 1000-1500 J/kg range seems plausible in a narrow
   southwest/northeast corridor across parts of New England, with poor
   mid-level lapse rates likely limiting the development of stronger

   Current expectations are for storms to form by late Saturday morning
   across the Northeast along the cold front, and subsequently
   strengthen as they approach the Atlantic Coast by mid afternoon.
   Isolated strong to damaging winds should be the main threat with
   this convection, as 25-35 kt of mid-level flow and related bulk
   shear act to modestly organize updrafts. A relatively greater
   potential for damaging winds may exist across parts of ME into NH
   where the best combination of instability and modest shear is
   forecast to occur. A small Slight Risk has been included across this
   area to account for this potential. Farther south/west into the Mid
   Atlantic and parts of the OH Valley, shear will be even weaker. This
   will tend to limit storm organization, but isolated strong/gusty
   winds producing occasional damage could still occur as storms move
   southeastward through Saturday evening.

   ...Northern/Central Rockies into the Adjacent High Plains...
   An upper trough/low will remain over the West Coast and British
   Columbia Saturday. Small-scale perturbations embedded within this
   large-scale upper troughing and orographic lift will likely
   encourage convective initiation along the higher terrain of the
   northern/central Rockies by early Saturday afternoon. These isolated
   to scattered storms will subsequently move eastward across the High
   Plains through Saturday evening. Steep mid-level lapse rates should
   once again be present over much of the northern/central High Plains.
   Relatively greater low-level moisture should exist across parts of
   eastern CO/WY into western NE/KS, and moderate to locally strong
   instability will probably develop through peak heating across these
   areas. Although low-level winds will remain generally weak, a
   strongly veering wind profile and enhanced mid/upper-level flow
   should result in about 35-40 kt of effective bulk shear. This
   forecast combination of instability and shear will probably support
   supercells initially, with mainly an isolated large hail threat.
   Some possibility for clustering into one or more small bowing
   segments may exist early Saturday evening, with a potentially
   damaging wind threat.

   Across the northern High Plains, low-level moisture is expected to
   remain more limited, which should temper instability somewhat. While
   some risk for hail and gusty winds should exist with the strongest
   convection, this threat should remain quite isolated. Farther south,
   mid-level flow should be comparatively weaker from southern CO into
   northeastern NM. While loosely organized storms could pose an
   isolated severe threat across this region, the overall threat should
   be marginal.

   Tornado:   2%     - Marginal
   Wind:     15%     - Slight
   Hail:     15%     - Slight

   ..Gleason.. 07/05/2019