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.
Tornado Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
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.
Charlotte, NC...Kansas City, MO...Virginia Beach, VA...Atlanta, GA...Omaha, NE...
SPC AC 180600
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT MON AUG 18 2014
VALID 181200Z - 191200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF SERN MN/WRN
WI/IA...
...SUMMARY...
ISOLATED SEVERE STORMS -- AND ASSOCIATED THREAT FOR DAMAGING WINDS
AND LARGE HAIL -- WILL BE POSSIBLE MONDAY AFTERNOON AND EVENING FROM
PORTIONS OF MINNESOTA AND WISCONSIN SOUTH-SOUTHWESTWARD ACROSS IOWA
AND INTO PORTIONS OF MISSOURI AND KANSAS. A FEW STRONG TO SEVERE
STORMS CAPABLE OF PRODUCING GUSTY WINDS AND MARGINAL HAIL CAN ALSO
BE EXPECTED FROM SOUTHERN ARKANSAS AND NORTHERN LOUISIANA
EAST-NORTHEASTWARD TO THE CAROLINAS AND SOUTHERN VIRGINIA.
...SYNOPSIS...
A MID-LEVEL SHORT-WAVE TROUGH IS PROGGED TO SHIFT ESEWD FROM THE NRN
PLAINS TO THE UPPER MS VALLEY/WRN UPPER GREAT LAKES REGION THROUGH
THE PERIOD. THIS FEATURE WILL BE ACCOMPANIED BY A BELT OF 30 TO 50
KT MID-LEVEL WNWLYS -- THE CORE OF WHICH SHOULD RESIDE ACROSS THE
MID MO VALLEY VICINITY DURING THE AFTERNOON AND EVENING HOURS.
ELSEWHERE...AN UPPER LOW IS PROGGED TO SHIFT SWD ALONG THE OREGON/CA
COAST WITH TIME...WHILE A VORT MAX EMBEDDED IN A BELT OF SOMEWHAT
ENHANCED MID-LEVEL WSWLYS CROSSES THE CENTRAL GULF COAST REGION
THROUGH 19/12Z.
...SERN MN/WRN WI SWD ACROSS IA...
CONVECTIVE/SEVERE RISK ACROSS THE UPPER MS/MID AND LOWER MO VALLEYS
REMAINS DIFFICULT TO ASCERTAIN WITH ANY DEGREE OF CERTAINTY
ATTM...IN PART DUE TO AREAS OF CONVECTION AND ASSOCIATED OUTFLOW
BOUNDARIES/CLOUD DEBRIS EXPECTED TO BE ONGOING AT THE START OF THE
PERIOD.
IN GENERAL...THE CONTINUED ESEWD ADVANCE OF THE NRN PLAINS VORT MAX
WILL PROVIDE LARGE-SCALE ASCENT FROM ROUGHLY THE MID MO VALLEY
REGION NWD...WHILE A WEAK SURFACE FRONT CROSSES THE MN/IA/ERN
NEB/NERN KS VICINITY DURING THE AFTERNOON. THOUGH GREATER
INSTABILITY -- ASSOCIATED WITH A PLUME OF STEEP MID-LEVEL LAPSE
RATES -- IS FORECAST ACROSS THE CENTRAL PLAINS...WEAKER
SYNOPTIC-SCALE UVV SHOULD PROVE GENERALLY INSUFFICIENT TO ALLOW
CONVECTIVE UPDRAFTS ALONG THE ADVANCING SURFACE FRONT TO BREACH THE
CAPPING LAYER. THUS -- WILL MAINTAIN ONLY 5% CONDITIONAL SEVERE
RISK SW OF THE MID MO VALLEY.
WITH GREATER CONVECTIVE COVERAGE CONFINED TO AREAS FARTHER N --
WHERE WEAKER INSTABILITY IS PROGGED...DEGREE OF SEVERE RISK REMAINS
SOMEWHAT UNCERTAIN. WITH THAT SAID...PRESENCE OF THE MID-LEVEL JET
CROSSING SRN MN/IA DURING THE AFTERNOON SHOULD SUPPORT UPDRAFT
ORGANIZATION/ROTATION...AND THUS AN UPGRADE TO SLIGHT RISK IS BEING
INCLUDED THIS FORECAST FOR STORMS EXPECTED TO DEVELOP NEAR THE FRONT
AS IT CROSSES MN/WRN IA DURING THE AFTERNOON. LARGE HAIL AND
LOCALLY DAMAGING WINDS WILL BE THE PRIMARY SEVERE RISK ACROSS THIS
AREA...WITH SOME RISK PERSISTING INTO THE EVENING HOURS AND PERHAPS
EXPANDING SWD INTO NRN MO AFTER DARK...AS A SWLY LOW-LEVEL JET
DEVELOPS SUPPORTING CONTINUED CONVECTION.
...SRN AR/NRN LA EWD ACROSS THE SOUTHEAST TO THE CAROLINAS/SRN VA...
SCATTERED TO WIDESPREAD SHOWERS AND THUNDERSTORMS ARE FORECAST TO
DEVELOP THROUGH THE DIURNAL PEAK HEATING CYCLE FROM THE LOWER MS
VALLEY VICINITY ENEWD ACROSS THE CENTRAL GULF COAST STATES AND INTO
THE CAROLINAS/SRN VA...AS THE MOIST AIRMASS IN PLACE DESTABILIZES
MODESTLY THROUGH THE AFTERNOON. HOWEVER...WIDESPREAD CONVECTION
WILL FACILITATE MAINTENANCE OF WEAK MID-LEVEL LAPSE RATES -- WHICH
SHOULD HINDER MORE SUBSTANTIAL CAPE DEVELOPMENT.
DESPITE LACK OF A CLEAR SYNOPTIC-SCALE LOW-LEVEL FOCUS FOR
CONVECTIVE INITIATION...ASCENT ASSOCIATED WITH THE EWD PROGRESSION
OF A WEAK MID-LEVEL VORT MAX SHOULD SUPPORT WIDESPREAD CONVECTION.
THOUGH THE LACK OF MORE SUBSTANTIAL CAPE IN MOST AREAS SHOULD LIMIT
OVERALL SEVERE RISK...20 TO 30 KT WSWLY FLOW IN THE H8 TO H5 LAYER
SUGGESTS SOME POTENTIAL FOR STORMS TO ORGANIZE INTO SMALL BANDS --
AND ASSOCIATED RISK FOR ISOLATED/MARGINAL HAIL AND/OR WIND GUSTS
SUPPORT EXPANSION OF 5% RISK AREA ACROSS THIS REGION.
..GOSS/ROGERS.. 08/18/2014
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
| 
)
