[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 240603
SWODY2
SPC AC 240602

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0102 AM CDT SUN APR 24 2005

VALID 251200Z - 261200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 35 SSW
PSX SAT 40 E JCT BWD SPS 30 NW OKC JLN SGF UNO MEM CBM 35 WSW 0A8 30
S SEM DHN MAI 25 WNW AQQ.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM DRT SJT 45 NNW SJT
BGS MAF INK ELP SAD IGM DRA RBL MFR EUG SLE PDX YKM ALW BOI TWF EVW
VEL CAG LAR CYS LIC 55 N LAA GLD EAR YKN AXN BJI 50 SSW INL RHI MTW
AZO FWA MIE BMG OWB BNA RMG ATL ABY 50 SSE TLH.

...THERE IS A SLGT RISK OF SVR TSTMS POTIONS CENTRAL/ERN TX/OK TO
LOWER MS VALLEY AND WRN FL PANHANDLE...

...SYNOPSIS...
UPPER AIR PATTERN WILL REMAIN DOMINATED BY BROAD GREAT LAKES
CYCLONE...WHICH IS FCST TO CONTINUE FILLING AND LIFTING NWD OVER
SWRN QUE THROUGH PERIOD.  HOWEVER...SHORTWAVE TROUGH -- NOW EVIDENT
IN MOISTURE CHANNEL IMAGERY OVER SERN NWT AND EXTREME NRN MB -- IS
EXPECTED TO AMPLIFY AND DIG SWD WITHIN WRN SEMICIRCLE OF GREAT LAKES
VORTEX.  AS THIS OCCURS...MARGINALLY CLOSED MID/UPPER LEVEL LOW NOW
MOVING ASHORE SRN CA WILL BECOME ENTRAINED INTO TIGHTENING HEIGHT
GRADIENTS OVER SRN PLAINS AND ACCELERATE SEWD ACROSS NRN TX AS
OPEN-WAVE TROUGH.

ASSOCIATED SFC CYCLOGENESIS LATE DAY-1 OVER ERN CO WILL LEAD TO 
PRONOUNCED SFC LOW...PRECEDING MIDLEVEL TROUGH DURING DAY2 PERIOD
ACROSS NWRN/N-CENTRAL TX OR SWRN/S-CENTRAL OK. BY 26/00Z...SFC
CYCLONE SHOULD SETTLE INTO AREA BETWEEN OKC-DFW-SPS...SHARPENING
DRYLINE EXTENDING SWD ACROSS CENTRAL TX...COLD FRONT NEWD ACROSS ERN
KS AND IA TO FRONTAL WAVE LOW INVOF WRN/CENTRAL WI.  AS SRN STREAM
MIDLEVEL TROUGH WEAKENS OVERNIGHT...SO WILL ASSOCIATED SFC LOW.  BY
END OF PERIOD...COLD FRONT SHOULD EXTEND FROM WI CYCLONE SWWD ACROSS
SERN MO TO S-CENTRAL/SW TX...DRYLINE ALIGNED NE-SW ACROSS TX COASTAL
PLAIN.

...SRN PLAINS TO LOWER MS VALLEY...
SCATTERED TSTMS FCST TO DEVELOP ALONG AND E OF DRYLINE AND COLD
FRONT DURING AFTERNOON...PERSISTING THROUGH EVENING WITH ONE OR MORE
MCS EVOLVING AFTER DARK.  SOME SUPERCELLS MAY DEVELOP WITH DAMAGING
HAIL AND POTENTIAL FOR TORNADOES DURING AFTERNOON/EVENING OVER
PORTIONS CENTRAL/NRN/ERN TX AND PERHAPS S-CENTRAL/SERN OK...SHIFTING
EWD SUBSEQUENTLY OVER ARKLATEX...E TX AND LA.  SEVERE POTENTIAL MAY
SHIFT INTO PORTIONS MS/AL OVERNIGHT.

VERTICAL SHEAR PROFILES ARE FCST TO STRENGTHEN THROUGHOUT PERIOD
AHEAD OF MIDLEVEL WAVE...AND OVER MUCH OF MOIST SECTOR.  COMBINATION
OF ISALLOBARICALLY FORCED FLOW BACKING AHEAD OF SFC CYCLONE...AND
TIGHTENING MIDLEVEL GRADIENTS...WILL RESULT IN FAVORABLY ENLARGED
LOW LEVEL HODOGRAPHS AND BULK SHEARS...I.E. 0-1 KM SRH 100-200 J/KG
AND 50-60 KT EFFECTIVE LOW-MIDLEVEL SHEAR.  THIS SUPPORTS POTENTIAL
FOR ALL MODES OF SEVERE...INCLUDING SOME SIGNIFICANT
EVENTS...ASSOCIATED WITH SUPERCELLS AND BOWS.

BIGGEST CONCERN -- AND WHAT KEEPS PROBABILITIES BARELY BELOW
CATEGORICAL MDT RISK THRESHOLDS ATTM -- REMAINS UNCERTAINTIES ABOUT
MAGNITUDE AND SPATIAL EXTENT OF BOUNDARY LAYER MOISTURE RETURN
ACROSS OUTLOOK AREA.  MODIFIED MODEL FCST SOUNDINGS INDICATE LOW 60S
F SFC DEW POINTS OVER N-CENTRAL/NE TX...AND MID 60S SE TX...WILL BE
SUFFICIENT IN COMBINATION WITH DIURNAL HEATING AND DRYLINE LIFT TO
BREAK CAP.  SLIGHTLY HIGHER DEW POINTS WILL LOWER LCL AND INCREASE
PROBABILITIES FOR SIGNIFICANT TORNADOES.  ATTM POST-FRONTAL
CONTINENTAL HIGH AND ASSOCIATED OFFSHORE FLOW HAVE SHUNTED MID 60S
DEW POINTS TO TAMPICO AREA...70S INTO BAY OF CAMPECHE. COMBINATION
OF MARINE MODIFICATION JUST N OF PRESENT 60-65 DEG
ISODROSOTHERMS...AND MOIST ADVECTION IN LATE DAY1/EARLY DAY2 RETURN
FLOWS...SHOULD CONTRIBUTE TO 60S DEW POINTS AT LEAST INTO
CENTRAL/ERN TX...PERHAPS NEAR RED RIVER...IN NARROW CORRIDOR.  IN
THIS SCENARIO MLCAPES AROUND 2000 J/KG ARE POSSIBLE...GIVEN STEEP
8-9 DEG C/KM LAPSE RATES.  FAVORABLE BOUNDARY LAYER MOISTENING AND
MUCAPES OF AROUND 2000 J/KG MAY SPREAD EWD ACROSS LOWER MS VALLEY
OVERNIGHT...HELPING TO SUPPORT EWD SPREAD OF SEVERE THREAT.

...ELSEWHERE...
OCCASIONAL STRONG-SEVERE TSTMS MAY DEVELOP INVOF COLD FRONT FARTHER
N/NE ACROSS OZARKS...PERHAPS AS FAR N UPPER MS VALLEY...IN ZONE OF
STRONG DEEP-LAYER FORCING AHEAD OF NRN STREAM TROUGH.  LOW LEVEL
MOISTURE AND SFC-BASED BUOYANCY IS EXPECTED TO DIMINISH WITH NWD
EXTENT ACROSS OZARKS INTO IA...RESULTING IN MARGINAL/CONDITIONAL
SEVERE PROBABILITIES.

ETA/SPECTRAL INDICATE SOME POTENTIAL FOR TSTM DEVELOPMENT AHEAD OF
WEAK SRN STREAM MIDLEVEL WAVE...AND NEAR MARINE/WARM
FRONT...OVERNIGHT IN SERN LA/WRN FL PANHANDLE CORRIDOR.  ALTHOUGH
LAPSE RATES AND BUOYANCY WILL NOT BE AS LARGE AS FARTHER
W...VERTICAL SHEAR PROFILES INDICATE SEVERE THREAT WITH ANY SUCH
ACTIVITY AS WELL.

..EDWARDS.. 04/24/2005

...NOTICE...
THE STATION RELATIVE POINTS IN THIS PRODUCT ARE NOW AVAILABLE
SEPARATELY UNDER THE WMO HEADINGS WUUS01 PTSDY1...
WUUS02 PTSDY2...WUUS03 PTSDY3.  THE INCLUSION OF POINTS
IN THIS DISCUSSION WILL BE DISCONTINUED AFTER THE 2005
CONVECTIVE SEASON.  A PUBLIC NOTIFICATION STATEMENT (PNS)
WILL PROVIDE DETAILS ON THE TRANSITION.