DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 150600
SWODY1
SPC AC 150559

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1259 AM CDT SAT MAR 15 2014

VALID 151200Z - 161200Z

...THERE IS A SLGT RISK OF SVR TSTMS TODAY AND TONIGHT ACROSS PARTS
OF CENTRAL AND SOUTHEAST TEXAS INTO THE LOWER MISSISSIPPI
VALLEY/CENTRAL GULF COAST REGION...

...SYNOPSIS...
ALTHOUGH ITS AMPLITUDE LIKELY WILL BE SUPPRESSED BY A VIGOROUS SHORT
WAVE IMPULSE PROGRESSING THROUGH ITS CREST...ACROSS AND TO THE LEE
OF THE CANADIAN ROCKIES...A LARGE UPPER RIDGE APPEARS LIKELY TO
CONTINUE BUILDING ACROSS THE PACIFIC COAST THROUGH MUCH OF THE
INTERMOUNTAIN WEST AND NORTHERN U.S. ROCKIES TODAY. AS THIS
OCCURS...A SIGNIFICANT SHORT WAVE IMPULSE...NOW DIGGING ACROSS THE
NORTHERN ROCKIES...IS FORECAST TO CONTINUE MORE SHARPLY SOUTHWARD
THROUGH THE REMAINDER OF THE ROCKIES...TOWARD THE TEXAS BIG BEND
REGION. IN RESPONSE TO THIS DEVELOPMENT...THE SHORT WAVE
TROUGH...CURRENTLY TURNING EASTWARD ACROSS SOUTHERN NEW MEXICO AND
SOUTHWEST TEXAS...APPEARS LIKELY PIVOT NORTHEASTWARD...REACHING THE
OZARK PLATEAU BY 12Z SUNDAY. DOWNSTREAM...MID-LEVEL HEIGHTS WILL
BUILD ACROSS MUCH OF THE SOUTHEAST...BUT A DEEP CYCLONIC VORTEX
PROGRESSING ACROSS EASTERN CANADA MAY MAINTAIN CONSIDERABLE
INFLUENCE ON WEATHER EAST OF THE ROCKIES.

COLDEST NEAR-SURFACE AIR ASSOCIATED WITH THE EASTERN CANADIAN VORTEX
WILL REMAIN OVER THE GREAT LAKES AND PARTS OF THE NORTHEAST...BUT
THE SHALLOW SOUTHERN LEADING EDGE OF THIS AIR MASS IS EXPECTED TO
REACH AT LEAST THE SOUTHERN MID ATLANTIC COAST STATES AND PARTS OF
THE TENNESSEE VALLEY INTO THE OZARK PLATEAU BY EARLY SUNDAY. COLDER
AIR ALSO APPEAR LIKELY TO SURGE SOUTHWARD TO THE LEE OF THE
ROCKIES...THROUGH MUCH OF THE PLAINS...DURING THE LATTER HALF OF THE
PERIOD. AT THE SAME TIME...A LINGERING LOW/MID-LEVEL BAROCLINIC
ZONE ASSOCIATED WITH A PRIOR COLD INTRUSION MAY TIGHTEN SOME ACROSS
PARTS OF CENTRAL/SOUTHEAST TEXAS INTO CENTRAL GULF COASTAL AREAS.

MEANWHILE...A MODEST RETURN FLOW OF MOISTURE IS NOW UNDERWAY OFF THE
WESTERN GULF OF MEXICO INTO THE SOUTHERN PLAINS. WITH FURTHER
BOUNDARY-LAYER MOISTENING OVER THE GULF OF MEXICO TODAY...MORE
SUBSTANTIVE MOISTURE MAY EVENTUALLY REACH THE LOWER MISSISSIPPI
VALLEY/CENTRAL GULF COAST REGION TONIGHT...WHERE/WHEN MODELS SUGGEST
SOUTHERLY LOW-LEVEL FLOW FIELDS WILL STRENGTHEN IN RESPONSE TO
CYCLOGENESIS ALONG THE PRIMARY FRONTAL ZONE ACROSS THE SOUTHERN
PLAINS/OZARK PLATEAU REGION.

...SOUTHERN PLAINS...
CONSIDERABLE PRECIPITATION/CONVECTIVE DEVELOPMENT APPEARS POSSIBLE
IN ADVANCE OF THE LEAD SHORT WAVE...ACROSS PARTS OF OKLAHOMA AND
NORTHERN/CENTRAL TEXAS EARLY TODAY...BEFORE SUBSTANTIVE
BOUNDARY-LAYER DESTABILIZATION TAKES PLACE. ALONG THE SOUTHERN EDGE
OF THIS ACTIVITY...A ZONE OF DIFFERENTIAL SURFACE HEATING MAY BECOME
THE FOCUS FOR STRONGEST CONVECTIVE DEVELOPMENT LATE THIS AFTERNOON
AND EVENING...ROUGHLY ALONG AN AXIS SOUTHWEST THROUGH SOUTH AND EAST
OF THE DALLAS/FORT WORTH METROPLEX.

BOUNDARY-LAYER MOISTENING ALONG AND SOUTH OF THIS AXIS...COUPLED
WITH INSOLATION...IS EXPECTED TO CONTRIBUTE TO 500-1000 J/KG OF CAPE
BY LATE AFTERNOON...IN THE PRESENCE OF STRONG DEEP-LAYER SHEAR NEAR
A 50-60+ KT 500 MB JET STREAK. THIS ENVIRONMENT WILL BE CONDUCIVE
TO ORGANIZED STRONG/SEVERE CONVECTIVE DEVELOPMENT...INCLUDING THE
RISK FOR SUPERCELLS. AND THIS MAY BE REALIZED...AS A CYCLONIC
VORTICITY CENTER ASSOCIATED WITH THE UPPER IMPULSE APPROACHES THE
REGION TOWARD THE 15/21-16/00Z TIME FRAME.

...UPPER TEXAS COAST INTO LWR MS VALLEY/CENTRAL GULF COAST...
ASSOCIATED WITH THE MORE SUBSTANTIVE INLAND MOISTURE SURGE INTO A
DEVELOPING ZONE OF LOWER/MID TROPOSPHERIC WARM ADVECTION...
ADDITIONAL VIGOROUS CONVECTIVE DEVELOPMENT APPEARS POSSIBLE ACROSS
THE REGION TONIGHT. THIS WILL BE DISPLACED TO THE SOUTHEAST OF THE
DEVELOPING SURFACE CYCLONE ON THE PRIMARY FRONT TO THE NORTH.
HOWEVER...BOUNDARY-LAYER MOISTENING...COUPLED WITH STRENGTHENING
LOW-LEVEL AND DEEP-LAYER SHEAR WILL SUPPORT THE POTENTIAL FOR
SUPERCELLS...WITH THE RISK FOR TORNADOES...AND AN ORGANIZED
CONVECTIVE CLUSTER CAPABLE OF PRODUCING DAMAGING WIND GUSTS.

..KERR/LEITMAN.. 03/15/2014

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