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.
Indianapolis, IN...Boston, MA...Kansas City, MO...Colorado Springs, CO...St. Louis, MO...
SPC AC 191956
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0256 PM CDT SUN JUL 19 2015
VALID 192000Z - 201200Z
...THERE IS AN ENH RISK OF SVR TSTMS FROM WRN NY TO SRN NH...
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE OH VALLEY TO WRN NEW
ENGLAND...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CNTRL HIGH PLAINS...
...THERE IS A MRGL RISK OF SVR TSTMS FROM THE CENTRAL PLAINS TO NEW
ENGLAND...
...SUMMARY...
SCATTERED SEVERE THUNDERSTORMS WITH WIND AND POSSIBLY HAIL WILL
OCCUR LATER TODAY INTO TONIGHT FROM THE UPPER OHIO VALLEY INTO NEW
ENGLAND. SEVERE STORMS WITH HAIL AND WIND ALSO MAY AFFECT THE
CENTRAL HIGH PLAINS. A FEW MARGINALLY SEVERE STORMS ARE EXPECTED
FROM THE CENTRAL PLAINS INTO THE LOWER MISSOURI VALLEY.
...SYNOPSIS...
A FEW MINOR CHANGES HAVE BEEN MADE TO 1630Z OUTLOOK. HAVE OPTED TO
INCREASE SEVERE PROBS ACROSS SERN OH AND NRN WV. CONVECTION HAS
RECENTLY INCREASED ALONG OUTFLOW FROM DECAYED OVERNIGHT MCS OVER
OH/NRN KY. THIS ACTIVITY IS SLOWLY ORGANIZING AND IS PROGRESSING
DOWNSTREAM AT ROUGHLY 30KT. LOCALLY DAMAGING WINDS MAY ACCOMPANY
THE LEADING EDGE OF THIS TSTM COMPLEX AS IT PROGRESSES INTO WV
AROUND 22Z...PERHAPS REACHING THE WRN TIP OF THE MARYLAND PANHANDLE
BY 20/00-01Z.
ELSEWHERE...NO CHANGES TO PREVIOUS OUTLOOK.
..DARROW.. 07/19/2015
.PREV DISCUSSION... /ISSUED 1128 AM CDT SUN JUL 19 2015/
...SYNOPTIC SETUP...
ELONGATED RIDGE WILL PERSIST FROM THE SRN RCKYS AND PLNS TO THE S
ATLANTIC CST...KEEPING THE WLYS CONFINED TO THE N CNTRL AND NERN
STATES. ON THE WRN FLANK OF THE RIDGE...POSITIVE-TILT TROUGH WITH
SEVERAL EMBEDDED DISTURBANCES WILL UNDERGO FURTHER SHEARING ALONG A
WSW-ENE AXIS OVER CA AND THE NRN GRT BASIN.
WITHIN THE WLYS...ONE DISTURBANCE WILL CONTINUE NE ACROSS JAMES BAY
TODAY...ALLOWING FEATURE NOW OVER NRN WI TO SWEEP E INTO SW QUE BY
THIS EVE. FARTHER S...SATELLITE DATA ONCE AGAIN SHOW A SERIES OF
WEAKER DISTURBANCES TRACKING GENERALLY E OR ENE FROM THE CNTRL RCKYS
TO THE OH VLY...IN BELT OF SLIGHTLY ENHANCED FLOW IMMEDIATELY N OF
THE RIDGE.
WEAK FRONT THAT CROSSED THE UPR MS VLY YESTERDAY WILL CONTINUE E
INTO THE LWR GRT LKS BY THIS EVE AS DIFFUSE/FRACTURED WARM FRONT
ADVANCES NE ACROSS CNTRL/ERN NEW ENGLAND. FARTHER S...TROUGH WILL
STRENGTHEN SWWD IN THE LEE OF THE APPALACHIANS. IN THE PLNS...WRN
END OF FRONT AFFECTING THE GRT LKS SHOULD BECOME STNRY/FURTHER
WEAKEN OVER THE S CNTRL HIGH PLNS AS A WEAK LEE TROUGH DEVELOPS
DOWNSTREAM OF WRN WY UPR IMPULSE.
...MID-OH VLY INTO NEW ENGLAND THIS AFTN INTO TNGT...
30-40 KT WLY 700-500 MB FLOW WILL PREVAIL FROM NRN IND/OH INTO NEW
ENGLAND TODAY...DOWNSTREAM FROM WI UPR IMPULSE AND IN WAKE OF WEAKER
DISTURBANCE NOW CROSSING NRN NEW ENGLAND. MID-LVL FLOW WILL INCREASE
FROM W-TO-E THROUGH THE DAY AND INTO TNGT...ESPECIALLY ACROSS THE
LWR GRT LKS...WHERE 500 MB SPEEDS SHOULD BE AOA 50 KTS BY EVE.
WHILE FORCING FOR ASCENT ACROSS MUCH OF SLGT RISK AREA WILL BE WEAK
TO NEUTRAL THROUGH MUCH OF THE DAY...ASCENT WILL INCREASE LATER THIS
AFTN AND EVE OVER OH/NW PA AND WRN NY AS THE WI IMPULSE STREAKS EWD.
COUPLED WITH PRESENCE OF AMPLE MOISTURE /PW AOA 1.50 INCHES/ AND
STRONG DIFFERENTIAL HEATING ALONG LK BREEZE BOUNDARIES...SETUP
SHOULD PROMOTE DEVELOPMENT OF CLUSTERS/BANDS OF STRONG
STORMS...ESPECIALLY OVER UPSTATE NY. A FEW STORMS ALSO MAY MOVE INTO
THE REGION FROM SRN ONT THIS EVE...WITH THE COLD FRONT.
GIVEN 40+ KT WLY DEEP SHEAR...SETUP COULD YIELD EMBEDDED BOWING
SEGMENTS/SUSTAINED STORMS CAPABLE OF DMGG WIND AND POSSIBLY
MARGINALLY SVR HAIL OR A TORNADO. THIS ACTIVITY COULD PERSIST AS AN
MCS THROUGH LATE EVE AS FORCING FOR ASCENT SPREADS E ACROSS THE
HUDSON VLY INTO NEW ENGLAND.
IN THE MEANTIME...OTHER STORMS MAY ARISE ALONG DIFFERENTIAL HEATING
BOUNDARIES/WARM FRONTAL SEGMENTS FROM CNTRL/ERN NY INTO WRN/CNTRL
NEW ENGLAND TODAY. MID-LVL LAPSE RATES AND FORCING FOR ASCENT WILL
BE WEAK TO SLIGHTLY NEGATIVE BEHIND LEAD UPR DISTURBANCE. BUT WIND
PROFILES WITH A CONSIDERABLE DEGREE OF VERTICAL VEERING AMIDST
SUFFICIENTLY MOIST LOW-LVL ENVIRONMENT SUGGEST POTENTIAL FOR A FEW
SUSTAINED STORMS/TRANSIENT SUPERCELLS WITH A RISK FOR LOCALLY DMGG
WIND AND POSSIBLY A TORNADO.
...CNTRL HIGH PLNS THIS AFTN/EVE...
WEAK UPSLOPE FLOW WILL PREVAIL OVER THE CNTRL HIGH PLNS TODAY INVOF
DISSIPATING FRONT. POST-FRONTAL AIR MASS WILL BE INCREASINGLY
MOIST...ESPECIALLY WITH EWD EXTENT INTO KS...WITH PW RANGING FROM
AROUND 1.00 INCH NEAR DEN TO ABOVE 1.75 INCHES IN WRN KS. COUPLED
WITH STRONG SFC HEATING AND ASCENT WITH SRN BRANCH UPR IMPULSE NOW
OVER WRN CO...SETUP SHOULD SUPPORT NUMEROUS AFTN STORMS OVER THE CO
FRONT RANGE AND ADJACENT FOOTHILLS. OTHER STORMS SHOULD FORM ALONG
DEVELOPING LEE TROUGH EXTENDING NE INTO WRN/CNTRL NEB. GIVEN DEGREE
OF BUOYANCY...MODEST BUT VERTICALLY-VEERING WIND PROFILES WILL
SUPPORT SUSTAINED STORMS/MARGINAL SUPERCELLS WITH SVR WIND/HAIL AND
POSSIBLY A TORNADO OR TWO. THE STORMS SHOULD MERGE INTO AN
EWD-MOVING MCS DURING THE EVE.
...CNTRL PLNS TO LWR OH VLY...
DIFFERENTIAL HEATING AND LOCALLY-ENHANCED UPLIFT ALONG THE EDGES OF
OVERNGT CONVECTION FROM KS INTO THE LWR OH VLY WILL SERVE TO FOCUS
SCTD AREAS OF DIURNAL STORMS THIS AFTN. GIVEN DEGREE OF BUOYANCY
/POCKETS OF MLCAPE TO 3000 J PER KG/...ISOLD STRONG TO BRIEFLY SVR
STORMS WITH WIND AND PERHAPS HAIL MAY OCCUR. WEAK DEEP SHEAR/FORCING
FOR ASCENT ON NRN FRINGE OF DEEP ANTICYCLONE SHOULD PROHIBIT AN
ORGANIZED SVR THREAT. OTHER STORMS MAY SPREAD E ALONG WEAKENING
FRONT ACROSS THE REGION /ESPECIALLY KS/ LATE TNGT/EARLY MON...WITH
STRENGTHENING SWLY LLJ.
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z
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