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.
Houston, TX...San Antonio, TX...Oklahoma City, OK...Tulsa, OK...Wichita, KS...
SPC AC 230549
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1249 AM CDT THU APR 23 2015
VALID 231200Z - 241200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM MIDDAY INTO THE AFTERNOON
ACROSS PARTS OF SOUTHERN LOUISIANA...
...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTERNOON AND EVENING
ACROSS PARTS OF NORTHWEST TEXAS AND ADJACENT SOUTHWESTERN
OKLAHOMA...SOUTHWARD ACROSS THE EDWARDS PLATEAU INTO ADJACENT AREAS
OF THE RIO GRANDE VALLEY...
...THERE IS A MRGL RISK OF SVR TSTMS SURROUNDING THE SLIGHT RISK
AREAS....ACROSS THE CENTRAL PLAINS AND SOUTHERN PLAINS INTO THE
CENTRAL GULF COAST...
...THERE IS A MRGL RISK OF SVR TSTMS THIS AFTERNOON ACROSS SOUTHEAST
FLORIDA COASTAL AREAS...
...SUMMARY...
SCATTERED STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE TODAY ACROSS
THE CENTRAL HIGH PLAINS...THE SOUTHERN PLAINS...THE CENTRAL GULF
COAST REGION...AND SOUTHEAST FLORIDA COASTAL AREAS.
...SYNOPSIS...
WITHIN THE NORTHERN BRANCH OF SPLIT WESTERLIES EMANATING FROM THE
MID-LATITUDE PACIFIC...MODELS INDICATE THAT THE CENTER OF A
LARGE...COLD MID/UPPER LOW WILL REDEVELOP EASTWARD DURING THIS
PERIOD...FROM EASTERN ONTARIO INTO NORTHERN NEW ENGLAND BY 12Z
FRIDAY. AS THIS OCCURS...AND AN UPSTREAM CLOSED LOW GRADUALLY
MIGRATES INLAND ACROSS THE SOUTHERN BRITISH COLUMBIA/WASHINGTON
COAST...UPPER TROUGHING WITHIN THE SOUTHERN BRANCH...IN PHASE WITH
THE SUBTROPICAL STREAM...IS FORECAST TO DEVELOP EAST NORTHEASTWARD
TOWARD THE CENTRAL AND SOUTHERN ROCKIES. AS THE MOST PROMINENT
SHORT WAVE IMPULSE WITHIN THIS LATTER FEATURE SLOWLY PIVOTS ACROSS
BAJA AND THE GULF OF CALIFORNIA...BEFORE ACCELERATING NORTHEASTWARD
TOWARD THE SOUTHERN ROCKIES...DOWNSTREAM SHORT WAVE RIDGING APPEARS
LIKELY TO AMPLIFY ACROSS PARTS OF THE CENTRAL/SOUTHERN PLAINS
THROUGH MID/LOWER MISSISSIPPI VALLEY.
IN LOWER LEVELS...FURTHER SOUTHWARD ADVANCEMENT OF A COLD FRONT
THROUGH THE SOUTH ATLANTIC /EASTERN GULF COAST STATES IS EXPECTED.
THE TRAILING WESTERN FLANK OF THIS FRONT PROBABLY WILL REMAIN
STALLED NEAR/NORTH OF THE SOUTHERN PLAINS RED RIVER VALLEY THROUGH
THE DAY...BEFORE REDEVELOPING NORTHWARD INTO THE CENTRAL PLAINS
TONIGHT. AT THE SAME TIME...SURFACE TROUGHING SHOULD BEGIN TO
GRADUALLY DEEPEN ACROSS THE HIGH PLAINS. SEASONABLY MOIST AIR WILL
REMAIN CONFINED TO AREAS ALONG AND SOUTH OF THE FRONT...BUT SOME
INCREASE IN MOISTURE IS ALSO EXPECTED AS SOUTHEASTERLY/SOUTHERLY
LOW-LEVEL FLOW STRENGTHENS ACROSS THE HIGH PLAINS.
BENEATH SEASONABLY STEEP MID-LEVEL LAPSE RATES...THIS MOISTURE...
COUPLED WITH DAYTIME HEATING...WILL CONTRIBUTE TO SCATTERED
THUNDERSTORM ACTIVITY ACROSS THE HIGH PLAINS...PORTIONS OF THE
CENTRAL GULF COAST STATES...AND THE FLORIDA ATLANTIC COASTAL AREAS.
ADDITIONAL SCATTERED THUNDERSTORM ACTIVITY LIKELY WILL FORM WITH
DAYTIME HEATING ACROSS PARTS OF THE CENTRAL ROCKIES...THE GREAT
BASIN...THE SIERRA NEVADA AND ADJACENT INTERIOR VALLEYS OF
CALIFORNIA...AND THE MOGOLLON RIM AREA OF ARIZONA INTO THE MOUNTAINS
OF SOUTHWESTERN NEW MEXICO. WHILE MUCH OF THIS ACTIVITY DIMINISHES
THIS EVENING...INCREASING LARGE-SCALE ASCENT DOWNSTREAM OF THE
SOUTHERN BRANCH TROUGHING IS EXPECTED TO PROVIDE THE FORCING/FOCUS
FOR NEW STORM DEVELOPMENT ACROSS PARTS OF THE CENTRAL AND SOUTHERN
PLAINS.
...TEXAS AND ADJACENT SOUTHERN OKLAHOMA...
MOISTURE CONTENT IS EXPECTED TO REMAIN SUPPORTIVE OF SIZABLE MIXED
LAYER CAPE BY LATE AFTERNOON BENEATH RELATIVELY STEEP MID-LEVEL
LAPSE RATES. IN THE PRESENCE OF STRONG DEEP LAYER VERTICAL SHEAR
BENEATH 40-50+ KT SOUTHWESTERLY 500 MB FLOW...THE ENVIRONMENT SHOULD
BE CONDUCIVE TO SEVERE STORMS...INCLUDING SUPERCELLS...WHERE DEEP
CONVECTION CAN BE INITIATED AND MAINTAINED. THE DRYLINE SEEMS TO
PROVIDE THE MOST LIKELY FOCUS FOR THIS DURING THE LATE AFTERNOON OR
EARLY EVENING...PARTICULARLY ACROSS PARTS OF NORTHWEST AND WEST
CENTRAL TEXAS...WHERE IT APPEARS MID-LEVEL HEIGHT RISES COULD BE
SUPPRESSED/SLOWED BY THE PROGRESSION OF A WEAK MID-LEVEL IMPULSE.
...SOUTHERN LOUISIANA...
GUIDANCE SUGGESTS THAT FORCING ON THE NORTHEASTERN PERIPHERY OF THE
BUILDING MID-LEVEL RIDGE COULD SUPPORT INCREASING STORM DEVELOPMENT
BY MIDDAY...IN THE PRESENCE OF WEAK TO MODERATE BOUNDARY LAYER CAPE.
LOW-LEVEL FLOW WILL BE WEAK...BUT 40-50 KT WEST NORTHWESTERLY 500
MB FLOW WILL PROVIDE SUFFICIENT VERTICAL SHEAR FOR ORGANIZED STORM
DEVELOPMENT...INCLUDING SUPERCELLS.
...SOUTHEAST FLORIDA...
OUTPUT FROM THE NCEP SREF AND VARIOUS CONVECTION ALLOWING MODELS
SUGGEST THE POTENTIAL FOR VIGOROUS STORM DEVELOPMENT THIS
AFTERNOON...MAINLY NEAR COASTAL AREAS...ALONG THE SEA BREEZE. IF
THIS OCCURS...DEEP LAYER SHEAR AND INSTABILITY PROBABLY WILL BE
SUFFICIENT FOR AN ISOLATED SUPERCELL OR TWO.
...CENTRAL HIGH PLAINS...
A WEAK MID-LEVEL IMPULSE EMERGING FROM THE APPROACHING SOUTHERN
BRANCH TROUGHING PROBABLY WILL AID CONVECTIVE DEVELOPMENT FROM THE
FRONT RANGE OF THE ROCKIES NORTHWARD TOWARD THE BLACK HILLS BY LATE
AFTERNOON. LOW MOISTURE CONTENT APPEARS THE PRIMARY LIMITING FACTOR
TO HIGHER SEVERE PROBABILITIES AT THE PRESENT TIME...AS LAPSE RATES
ARE EXPECTED TO BE STEEP...AND VERTICAL SHEAR SHOULD BE AT LEAST
MARGINALLY SUFFICIENT FOR ISOLATED SUPERCELLS.
..KERR/ROGERS.. 04/23/2015
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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