DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 052004
SWODY1
SPC AC 052002

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0302 PM CDT THU JUL 05 2012

VALID 052000Z - 061200Z

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING FOR
THE CENTRAL/SOUTHERN APPALACHIANS AREA...

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT FROM
EASTERN WY/SOUTHEAST MT EASTWARD THROUGH THE NORTHERN PLAINS...

A FEW ADJUSTMENTS WERE MADE TO THE PREVIOUS OUTLOOK BASED ON
CONVECTIVE TRENDS AND LATEST OBSERVATIONS. HAVE EXTENDED THE SLIGHT
RISK NORTHWARD INTO SOUTHERN LOWER MI WHERE DESTABILIZATION IS
OCCURRING IN ADVANCE OF SOUTHWESTWARD MOVING OUTFLOW FROM EARLIER
CONVECTION. IN ADDITION...CINH CONTINUES TO ERODE GIVEN STRONG
HEATING AND TSTMS DEVELOPING IN THIS AREA MAY CONTINUE TO MOVE
GENERALLY SOUTHWARD THROUGH REMAINDER OF THIS AFTERNOON. DAMAGING
WINDS WOULD BE THE PRIMARY THREAT WITH ISOLATED LARGE HAIL ALSO
POSSIBLE.

ADJUSTED WIND AND HAIL PROBABILITIES IN ASSOCIATION WITH ON-GOING
OHIO VALLEY SEVERE MCS WHICH SHOULD CONTINUE MOVING GENERALLY
SOUTH/SOUTHWESTWARD THROUGH EARLY EVENING.

TRENDS IN VISIBLE SATELLITE IMAGERY AND LATEST CONVECTION-ALLOWING
MODEL GUIDANCE SUGGEST TSTMS MAY BE CLOSE TO INITIATING OVER
SOUTH-CENTRAL PA SOUTHWARD INTO MD WHERE MOISTURE IS POOLING IN
ADVANCE OF FRONTAL BOUNDARY. MLCAPE VALUES OF 3000 J/KG WITH LITTLE
IN THE WAY OF CINH SUGGEST THAT DAMAGING WINDS AND LARGE HAIL WILL
BE POSSIBLE.

REMAINDER OF CONUS REMAINS UNCHANGED FROM PREVIOUS OUTLOOK.

..BUNTING.. 07/05/2012

.PREV DISCUSSION... /ISSUED 1137 AM CDT THU JUL 05 2012/

...CENTRAL/SRN APPALACHIANS AND VICINITY THIS AFTERNOON...
CONVECTION HAS DEVELOPED AS OF LATE MORNING ACROSS CENTRAL WV
...ALONG A REMNANT OUTFLOW BOUNDARY FROM EARLY MORNING STORMS IN OH.
FARTHER S...A SMALL MCV PERSISTS OVER SE WV. STRONG SURFACE HEATING
IS UNDERWAY IN ADVANCE OF THE OUTFLOW AND MCV...WHERE AFTERNOON
MLCAPE SHOULD INCREASE TO THE 2500-4000 J/KG RANGE WITH STEEP
LOW-LEVEL LAPSE RATES AND MINIMAL CONVECTIVE INHIBITION. THUS...IT
APPEARS LIKELY THAT ADDITIONAL STORMS WILL FORM ALONG THE OUTFLOW
AND WITH THE MCV...AS WELL AS OVER THE HIGHER TERRAIN. ANTICYCLONIC
FLOW AROUND THE MID MS VALLEY UPPER HIGH WILL SUPPORT SWD MOTION OF
THE INITIAL STORMS IN THE WV AREA...AND A TENDENCY FOR MORE SWWD
MOTION OF THE CLUSTER LATER THIS AFTERNOON ACROSS ERN KY/TN.
DAMAGING WINDS SHOULD BE THE MAIN CONCERN BASED ON STEEP LOW-LEVEL
LAPSE RATES...LARGE DCAPE...AND PRECIPITATION LOADING IN THE
ENVIRONMENT WITH PW VALUES OF 1.50-1.75 INCHES. MARGINALLY SEVERE
HAIL WILL ALSO BE POSSIBLE GIVEN THE LARGE BUOYANCY...BUT RELATIVELY
WEAK VERTICAL SHEAR WILL TEND TO LIMIT UPDRAFT LONGEVITY AND
INDIVIDUAL STORM ORGANIZATION.

...SMALL PART OF SE PA/MD THIS AFTERNOON..
THE ERN EXTENT OF THE OH/PA OUTFLOW BOUNDARY APPEARS TO INTERSECT
THE SYNOPTIC FRONT ACROSS SE PA. STRONG SURFACE HEATING SE OF THIS
WEAK BOUNDARY INTERSECTION COULD SUPPORT THE DEVELOPMENT OF A SMALL
CLUSTER OF STORMS THIS AFTERNOON...WHERE VISIBLE IMAGERY SHOWS
CUMULUS DEVELOPMENT AS OF 16Z. THE MODERATE INSTABILITY/STEEP
LOW-LEVEL LAPSE RATE ENVIRONMENT WILL SUPPORT A RISK FOR DAMAGING
WINDS IF STORMS DO FORM IN THIS AREA AND MOVE SEWD TOWARD THE NRN
PART OF CHESAPEAKE BAY.

...ERN WY/SD AREA THROUGH TONIGHT...
SURFACE CYCLOGENESIS IS EXPECTED THIS AFTERNOON ACROSS CENTRAL/ERN
WY IN ADVANCE OF A SERIES OF SPEED MAXIMA ALOFT EJECTING NNEWD FROM
THE GREAT BASIN. IN RESPONSE TO THE PRESSURE FALLS ACROSS WY...THE
STALLED SURFACE FRONT IN NEB WILL MOVE NWD TO NEAR THE NEB/SD BORDER
BY THIS EVENING. A CORRIDOR OF RICHER BOUNDARY LAYER MOISTURE HAS
BEEN MAINTAINED NEAR AND JUST N OF THE FRONT...AND THIS MOISTURE
WILL CONTRIBUTE TO MODERATE-STRONG INSTABILITY ALONG AND JUST N OF
THE WARM FRONT...THOUGH MIDLEVEL LAPSE RATES ARE NOT AS STEEP AS
PRIOR DAYS AS A RESULT OF PRIOR CONVECTION OVER THE HIGH PLAINS AND
PLATEAU.

RESIDUAL CLOUDS DO COMPLICATE THE SCENARIO ACROSS NRN NEB/SRN
SD...AS WELL AS ERN WY...WHERE SURFACE HEATING WILL BE LIMITED SOME
THROUGH AT LEAST EARLY AFTERNOON. ALSO...DEEP-LAYER VERTICAL SHEAR
WILL NOT BE PARTICULARLY STRONG. A FEW STORMS COULD FORM ALONG THE
WARM FRONT THIS AFTERNOON AND POSE A RISK FOR ISOLATED LARGE
HAIL/DAMAGING WINDS...THOUGH THE MORE PROBABLE AREA FOR AT LEAST
MARGINAL SUPERCELL POTENTIAL WILL BE FROM EXTREME SW SD INTO E/NE WY
WHERE MORE CLOUD BREAKS ARE EXPECTED...AND IN CLOSER PROXIMITY TO
SOMEWHAT STRONGER FLOW ALOFT. OTHERWISE...A PRONOUNCED WARM
ADVECTION REGIME IS FORECAST OVERNIGHT ACROSS SD/SRN ND...WHERE A
CLUSTER OF STORMS APPEARS LIKELY. THE STRONGEST STORMS ON THE SRN
FLANK OF THIS CONVECTIVE SYSTEM COULD PRODUCE LARGE HAIL/DAMAGING
GUSTS OVERNIGHT.

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.