Boston, MA...Virginia Beach, VA...Norfolk, VA...Chesapeake, VA...Richmond, VA...
Probabilistic 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
5 %
105,157
16,026,976
Boston, MA...Virginia Beach, VA...Norfolk, VA...Chesapeake, VA...Richmond, VA...
SPC AC 210515
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1215 AM CDT Tue Aug 21 2018
Valid 221200Z - 231200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF NEW ENGLAND...THE COASTAL CAROLINAS/MID-ATLANTIC STATES AND
SOUTH-CENTRAL HIGH PLAINS...
...SUMMARY...
Isolated strong to severe thunderstorms may occur Wednesday across
portions of the coastal Carolinas/southeast Virginia and the
south-central High Plains.
...Synopsis...
Cyclonic flow aloft will persist across the majority of eastern
CONUS as a series of shortwave troughs move through the OH Valley
and Northeast States. Surface low attendant to the lead shortwave
trough will likely be centered over southern Quebec at the beginning
of the period, with a cold front extending southward through central
NY/PA then southwestward into the Carolina Piedmont.
Farther east, upper ridging will remain centered over the southern
Plains while shortwave ridging moves across the northern Plains and
upper Midwest ahead of a shortwave trough moving through the
northern Rockies and northern High Plains.
...Portions of New England...
Latest guidance suggests the cold front will move eastward
throughout the day, reaching eastern portions of New England during
the late morning/early afternoon. Moist profiles and widespread
cloudiness will limit destabilization but somewhat warmer and more
moist air will likely advect into the region just ahead of the
approaching cold front. Resulting modest instability will aid in the
development of scattered thunderstorms along and/or just ahead of
the cold front. Vertical shear is strong enough to support isolated
severe potential within any of the more persistent updrafts.
...Coastal Carolinas/Mid-Atlantic States...
Frontal position/timing and antecedent precipitation will play a
large role in modulating the severe potential across this region on
Wednesday. Current guidance indicates the cold front will likely
extend from the southern Delmarva Peninsula southwestward into
southeast GA. This frontal position would leave 70 dewpoints and
moderate instability in place across a southeast VA and the eastern
Carolinas. While there is some displacement between the better flow
aloft (north) and the stronger instability (south), enough overlap
exists to support the potential for a few severe storms from the
late morning into the evening.
...South-Central High Plains...
The region will be favorably placed along the northwestern periphery
of the upper ridge centered over central TX and along the
southwestern periphery of a surface high centered near the central
NE/KS border. As a result, modest westerly flow aloft will exist
atop moist, southeasterly upslope flow. Resulting vertical shear and
instability will favor the potential for a few strong to severe
storms as storms develop during the late afternoon and early
evening.
...MAXIMUM RISK BY HAZARD...
Tornado: 2% - Marginal
Wind: 5% - Marginal
Hail: 5% - Marginal
..Mosier.. 08/21/2018
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z