SWODY2
SPC AC 311730
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1230 PM CDT THU MAY 31 2007
VALID 011200Z - 021200Z
..THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE UPR MS
VLY/CORN BELT SWWD INTO THE SRN HIGH PLAINS...
..SYNOPSIS...
UPR LOW VCNTY SD WILL MOVE SLOWLY EWD TDY/FRI. SEVERAL LOBES OF
VORTICITY WILL ROTATE AROUND THIS LOW WITH SRN PERIPHERY OF THE
STRONGER H5 FLOW ROUGHLY ALONG 40 DEG N. AT THE SFC...A SYNOPTIC
BOUNDARY...ENHANCED BY CONVECTION WILL EXIST FROM A LOW OVER ERN SD
SWD INTO ERN NEB...ERN KS AND INTO THE SRN HIGH PLAINS DURING FRI
AFTN. A WARM FRONT WILL DEVELOP NWD THROUGH THE MIDWEST WHILE A
LEE-TROUGH/DRYLINE PERSISTS FROM ECNTRL NM INTO SWRN TX.
ELSEWHERE...A SHORTWAVE TROUGH NOW ENTERING THE WRN GULF BASIN IS
EXPECTED TO GRADUALLY SHIFT ENEWD TOWARD THE FL PENINSULA LATER IN
THE WEEK...BUT MODELS ARE AT ODDS WITH TIMING/LOCATION. TROPICAL
AIR MASS SHOULD ADVECT NWD AHEAD OF THIS FEATURE INTO AT LEAST
CNTRL/SRN FL BY FRI NIGHT.
..ERN PARTS OF CNTRL PLAINS NWD INTO THE CORN BELT...
ONE OR MORE MCS/S WILL LIKELY BE ONGOING AT 12Z FRI ACROSS PORTIONS
OF ERN NEB SWD INTO CNTRL/ERN KS ALONG THE NOSE OF THE LLJ WITHIN
PRE-FRONTAL WARM SECTOR. THIS ACTIVITY MAY CONTINUE EWD INTO PARTS
OF IA AND MO DURING THE MORNING WITH ATTENDANT ISOLD SVR THREATS.
LLJ WILL LIKELY PERSIST ALONG ERN PERIPHERY OF THE UPR LOW THROUGH
THE DAY. THIS SUGGESTS THAT TSTMS COULD BACKBUILD AND/OR DEVELOP
SEPARATELY DURING THE AFTN/EVE FROM PARTS OF WRN IA SWWD INTO ERN
KS. STRONGEST DESTABILIZATION WILL OCCUR ALONG OUTSKIRTS OF MORNING
STORMS ESPECIALLY WHERE 60S SFC DEW POINTS CAN RECOVER. BOTH
LOW-LEVEL HODOGRAPHS AND DEEP LAYER SHEAR WILL SUPPORT POTENTIAL
SUPERCELLS...THOUGH MUCH UNCERTAINTY EXISTS ON HOW THE STORMS WILL
EVOLVE. ALL FACETS OF SVR WEATHER APPEAR POSSIBLE WITH THE STORMS
THROUGH MID-EVENING BEFORE A WEAKENING TREND ENSUES NEAR THE MS RVR
VLY OVERNIGHT.
..SCNTRL PLAINS...
SRN-END OF ANY POTENTIAL MCS/S MAY BE ONGOING THROUGH FRI MORNING
ACROSS CNTRL/WRN OK...THOUGH STRONGEST SUPPORT WILL EXIST ACROSS THE
CNTRL PLAINS WHERE STRONGER FLOW/FORCING REGIMES WILL BE
ESTABLISHED. AIR MASS DOWNSTREAM ACROSS THE SCNTRL PLAINS AND AT
LEAST MODEST SLY LOW-LEVEL INFLOW COULD SUSTAIN ANY ESTABLISHED TSTM
CLUSTER INTO THE AFTN ACROSS OK AND N TX. OTHERWISE...IN WAKE OF
THE SYSTEM...DEPENDING ON THE MAGNITUDE OF RECOVERY... OTHER STORMS
MAY DEVELOP UPSTREAM ALONG THE PRIMARY COLD FRONT. THIS ACTIVITY
COULD SPREAD SEWD ACROSS CNTRL/ERN OK FRI NIGHT WITH ISOLD HIGH
WINDS/HAIL.
..SRN HIGH PLAINS OF ERN NM AND WRN TX...
OUTFLOW FROM CNTRL PLAINS TSTMS SHOULD BACKDOOR WWD ACROSS NERN NM
AND THE TX/OK HIGH PLAINS EARLY FRI. ELY COMPONENT OF MOIST
BOUNDARY LAYER FLOW BENEATH STEEP LAPSE RATES AND POTENTIAL FOR AFTN
INSOLATION SHOULD PROVE FAVORABLE FOR HIGH ELEVATION TSTM INITIATION
BY MID-AFTN FRI. TSTMS WILL TEND TO DEVELOP/PROPAGATE ALONG AN AXIS
OF INSTABILITY INTO THE TX PNHDL AND NWRN TX DURING THE EVE. OTHER
ISOLD STORMS MAY FORM FARTHER S ALONG THE DRYLINE INTO SWRN TX.
UPR FLOW REGIME WILL BE COMPARATIVELY WEAKER THAN AT POINTS FARTHER
N. DESPITE THE WEAKER FLOW...DIRECTIONAL SHEAR MAY BECOME AT LEAST
MARGINALLY SUFFICIENT FOR SUPERCELL STRUCTURES. PRIMARY THREATS WILL
BE ISOLATED DAMAGING WIND AND LARGE HAIL.
..NRN PLAINS...
LOW-TOPPED TSTMS MAY DEVELOP BENEATH COLD CORE ALOFT ACCOMPANYING H5
LOW OVER PARTS OF THE CNTRL/ERN DAKS FRI AFTN. ISOLD STORMS MAY
PRODUCE BRIEF TORNADOES/HAIL.
..CNTRL/SRN FL...
DEPENDING ON HOW FAR EAST UPPER LOW OVER NRN GULF PROGRESSES...
HODOGRAPHS MAY BECOME INCREASINGLY SUPPORTIVE OF SUPERCELL
STRUCTURES/TORNADOES. HOWEVER... THE WEAK MID LEVEL LAPSE RATES AND
POTENTIAL FOR WIDESPREAD CLOUDS WILL LIKELY LIMIT INSTABILITY IN
THIS REGION. THIS AND THE UNCERTAINTY IN THE EJECTION/EVOLUTION OF
THE TROUGH WILL PRECLUDE CATEGORICAL SLGT RISK ATTM.
.RACY.. 05/31/2007
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