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
2 %
44,800
6,027,955
Virginia Beach, VA...Norfolk, VA...Chesapeake, VA...Richmond, VA...Newport News, VA...
Probabilistic Damaging Wind 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
15 %
45,720
5,798,311
Virginia Beach, VA...Norfolk, VA...Chesapeake, VA...Richmond, VA...Newport News, VA...
SPC AC 311248
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0748 AM CDT Fri Mar 31 2017
Valid 311300Z - 011200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TODAY FROM EASTERN
NORTH CAROLINA INTO SOUTHEASTERN VIRGINIA...
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SURROUNDING THE
NORTH CAROLINA AND VIRGINIA SLIGHT RISK AREA...
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WESTERN
OKLAHOMA AND THE TEXAS PANHANDLE INTO SOUTHERN KANSAS...
...SUMMARY...
A few severe thunderstorms with damaging winds, isolated large hail,
and perhaps a tornado, are expected today across North Carolina and
Virginia. Isolated, marginally severe hail will be possible tonight
across parts of Kansas/western Oklahoma and the Texas/Oklahoma
Panhandles.
...North Carolina/Virginia area through this afternoon...
A midlevel trough over the OH Valley this morning will progress
eastward to the Mid Atlantic coast tonight, as an associated surface
cyclone and cold front likewise cross NC/VA during the afternoon.
An initial band of convection across eastern NC this morning will
pose a marginal risk for damaging winds or a tornado in conjunction
with a moistening boundary layer (mid 60s dewpoints) and an increase
in low-level shear. In the wake of this morning convection, some
surface heating is expected in advance of the surface cold front.
Destabilization in a corridor ahead of the front will contribute to
thunderstorm development along and east of the boundary by early
afternoon, and the storms will cross eastern NC and VA during the
afternoon/evening. Sufficient buoyancy (MLCAPE 500-1000 J/kg) and
deep-layer vertical shear (effective bulk wind differences in excess
of 40 kt) will support a risk of supercells/organized line segments
capable of producing damaging gusts and marginally severe hail. An
isolated tornado or two cannot be ruled out with the more discrete
storms given a moist boundary layer and effective SRH near 200
m2/s2.
...Texas Panhandle to southwest Kansas tonight...
Initial low-level moisture return will occur today across TX in
response to cyclogenesis across the southern High Plains (downstream
from a closed low passing south of the Four Corners). 12z soundings
along the TX coast suggest the moist layer will be shallow and
susceptible to vertical mixing today. A gradual increase in
moisture by tonight should be sufficient for thunderstorm
development to the north of a slow-moving front in a low-level
warm-advection regime from the TX Panhandle into western OK and
southwestern KS. The NAM appears to be too aggressive with the
moisture return and resultant buoyancy tonight, while the RAP/GFS
forecasts of 1000-1500 J/kg MUCAPE look more reasonable. The
combination of modest buoyancy rooted in the 850-700 mb layer,
midlevel lapse rates at or above 8 C/km and effective bulk shear in
excess of 40 kt could support some storm organization and a risk for
isolated marginally severe hail.
..Thompson.. 03/31/2017
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
| 
)
