SWODY2
SPC AC 100602
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1202 AM CST SUN FEB 10 2008
VALID 111200Z - 121200Z
..THERE IS A SLGT RISK OF SVR TSTMS LATE MON AFTN/MON EVE ACROSS
PARTS OF THE S CNTRL PLAINS....
..SYNOPSIS...
MODELS CONTINUE TO INDICATE AN AMPLIFICATION WITHIN THE STRONGER
BELT OF WESTERLIES ACROSS THE NORTHERN/EASTERN PACIFIC INTO THE
INTERMOUNTAIN WEST/ROCKIES LATER TODAY. AND...THIS IS PROGGED TO
TRANSLATE EASTWARD THROUGH MUCH OF THE REMAINDER OF THE U.S. BY 12Z
TUESDAY. WITHIN THIS REGIME...A SIGNIFICANT SHORT WAVE TROUGH IS
PROGGED TO DIG TO THE LEE OF THE NORTHERN/CENTRAL ROCKIES
MONDAY...AS AN UPSTREAM RIDGE BUILDS ACROSS PACIFIC COASTAL AREAS.
AT THE SAME TIME...MODELS SUGGEST THAT FLOW WILL STRENGTHEN WITHIN A
BELT EXTENDING OUT OF THE SUBTROPICAL PACIFIC THROUGH THE MEXICAN
PLATEAU...TO THE REAR OF A BROAD IMPULSE PROGRESSING ACROSS LOWER
TEXAS/MEXICAN GULF COASTAL AREAS INTO THE WESTERN/CENTRAL GULF OF
MEXICO.
CONSIDERABLE SPREAD PERSISTS AMONG THE MODELS CONCERNING THE
EVOLUTION OF THE DIGGING SHORT WAVE TO THE LEE OF THE ROCKIES...AND
RELATED DEVELOPMENTS REGARDING THE INFLUENCE OF THE NEXT STRONG
IMPULSE ON THE WESTERN STATES RIDGE...AS IT APPROACHES THE BRITISH
COLUMBIA/PACIFIC NORTHWEST COAST LATE IN THE PERIOD. UNCERTAINTIES
ALSO EXIST CONCERNING THE EXTENT OF THE ONGOING ARCTIC INTRUSION
INTO THE CENTRAL/EASTERN STATES...AND ITS SUBSEQUENT MODIFICATION IN
THE WAKE OF AN ASSOCIATED MID-LEVEL VORTEX...WHICH IS PROGGED TO
LIFT AWAY FROM NORTH ATLANTIC COASTAL AREAS EARLY IN THE PERIOD.
BUT...THE BULK OF GUIDANCE CONTINUES TO INDICATE THE DEVELOPMENT OF
SUBSTANTIAL CONDITIONAL/CONVECTIVE INSTABILITY BY MONDAY ACROSS THE
SOUTH CENTRAL PLAINS INTO PARTS OF THE OZARK PLATEAU...AS A MOIST
RETURN FLOW CONTINUES BENEATH AN ELEVATED MIXED LAYER EMANATING FROM
THE SOUTHERN ROCKIES/PLATEAU REGION.
..SOUTH CENTRAL STATES...
STEEPENING MOIST ISENTROPIC ASCENT...ASSOCIATED WITH A STRENGTHENING
LOW-LEVEL JET ON THE NOSE OF THE ELEVATED WARM LAYER ...IS EXPECTED
TO SUPPORT THE DEVELOPMENT OF SCATTERED THUNDERSTORMS ACROSS PARTS
OF THE EAST CENTRAL PLAINS INTO THE OZARKS SHORTLY AFTER 12Z
MONDAY...IF NOT BEFORE. AND...THIS FORCING IS PROGGED TO GRADUALLY
SHIFT EASTWARD TOWARD THE LOWER OHIO VALLEY DURING THE DAY.
IN ITS WAKE...THE GFS AND ECMWF ARE SIMILAR IN INDICATING THAT
CONDITIONAL AND CONVECTIVE INSTABILITY WILL BECOME MAXIMIZED ACROSS
CENTRAL/EASTERN OKLAHOMA BY LATE MONDAY AFTERNOON...NEAR THE
INTERSECTION OF THE NOSE OF THE ELEVATED MIXED LAYER...THE LOW-LEVEL
MOIST TONGUE AND FRONTAL ZONE. IT SEEMS PROBABLE THAT A SHALLOWER
COLD FRONT WILL PRECEDE THE DEEPER COLD SURGE INTO THE RED RIVER
VALLEY. BUT...ELEVATED INSTABILITY IS STILL EXPECTED TO BECOME
SUFFICIENT FOR VIGOROUS CONVECTIVE DEVELOPMENT...INCLUDING A FEW
SEVERE STORMS. THIS SHOULD OCCUR AS INTERACTING BELTS OF WESTERLIES
CONTRIBUTE TO A STRENGTHENING DIVERGENT UPPER FLOW FIELD...FOCUSED
ACROSS THE SOUTH CENTRAL PLAINS...BY EARLY MONDAY EVENING.
STRONG SHEAR THROUGH THE CLOUD BEARING LAYER WILL BE SUPPORTIVE OF
UPDRAFT ROTATION. AND...A FEW SUPERCELLS CAPABLE OF PRODUCING LARGE
HAIL WILL BE POSSIBLE...BEFORE ACTIVITY EXPANDS IN COVERAGE ABOVE
THE FRONTAL INVERSION...ALONG THE FRONTAL ZONE...AS THE FRONT BEGINS
TO ADVANCE SOUTHWARD THROUGH THE OZARK PLATEAU/RED RIVER VALLEY
MONDAY EVENING.
.KERR.. 02/10/2008
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