[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 181247
SWODY1
SPC AC 181245

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0745 AM CDT MON APR 18 2005

VALID 181300Z - 191200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 35 SW
SJT 15 SE MAF 30 W PVW 15 E EHA 50 NNE HLC 20 ENE BUB FSD 25 NNW FRM
20 NNE MCW 25 NW CID 20 NW IRK MKC 15 SW ICT 30 SSW END 15 N SPS 45
ENE SJT 35 SW SJT.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 75 ESE ANJ 40 WNW PLN
20 WNW TVC 25 SSE HTL 25 NW MTC 10 SSE CLE 15 WSW PIT 20 ESE EKN 25
WSW SHD 10 WSW ROA 25 SSW PSK 40 E TRI 45 SSE JKL 40 NE SDF 20 SW
BMG 30 ENE ALN 30 S STL 45 SSE VIH 30 ENE FYV 40 SW PRX 50 SE AUS 25
SSW CRP 50 SSW ALI 40 S LRD ...CONT... 20 SSE ELP 30 N HOB 30 SSE
LAA 40 E AKO 25 NE LAR 40 NW RWL 45 NW RKS 20 ENE U28 25 NW 4HV 40
NNE BCE CDC 10 NE P38 70 WNW P38 45 NW TPH 60 S NFL 30 ENE TVL 35
WNW RNO 15 SSE SVE 15 E SVE 50 NW LOL 25 NNE LOL 35 S BAM 55 S EKO
35 SSW ENV 25 NNW ENV 20 NW OWY 50 SW BNO 45 NNE MFR 50 NNE 4BK 30
SW OTH ...CONT... 80 ENE HVR 40 SE HVR 50 ENE HLN 15 SW LVM 55 W 4BQ
50 E MLS 10 SW P24 60 N DVL.

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE SRN AND CNTRL
PLNS...

...SYNOPSIS...
SATELLITE LOOPS SHOW HIGH AMPLITUDE RIDGE NOSING N INTO THE GULF OF
AK ATTM...SUGGESTING THAT DOWNSTREAM TROUGH NOW SETTLING INTO THE
NRN GRT BASIN SHOULD CONTINUE TO DEEPEN.  THIS SHOULD LEAD TO CLOSED
LOW DEVELOPMENT OVER NRN NV BY 12Z TUESDAY.  FARTHER S...SATELLITE
DATA ALSO INDICATE THAT THE SRN STREAM JET WILL REMAIN AN IMPORTANT
FACTOR GOVERNING CONVECTIVE EVOLUTION OVER THE CNTRL AND SRN PLNS. 
LEAD PORTION OF COMPLEX SHORTWAVE SYSTEM WITHIN THIS FLOW...NOW OVER
N CNTRL KS/SRN NEB...SHOULD CONTINUE NEWD TODAY AND REACH ERN IA
EARLY TUESDAY. SEVERAL WEAKER DISTURBANCES ARE EVIDENT UPSTREAM IN
THE SRN BRANCH OVER NM/AZ...AS ARE IMPULSES IN THE SUBTROPICAL JET A
BIT FARTHER TO THE SOUTH.

AT LOWER LEVELS...PARTIALLY MODIFIED GULF AIR WILL CONTINUE TO
SPREAD N ACROSS MUCH OF THE PLNS AND INTO PARTS OF THE LWR MO/UPR MS
VLYS.  COLD FRONT ASSOCIATED WITH GREAT BASIN TROUGH SHOULD SETTLE
SE ACROSS ND/MN IN RESPONSE TO A NRN STREAM SPEED MAX TRACKING E
ACROSS MANITOBA.

...SRN HI PLNS...
CONDITIONS SHOULD BECOME FAVORABLE FOR DIURNAL STORM DEVELOPMENT
ALONG LEE TROUGH/DRY LINE OVER THE SRN HI PLNS LATER TODAY.  THIS
WILL BE ESPECIALLY TRUE IN W TX...WHERE CONVERGENCE ALONG THE TROUGH
MAY BE SOMEWHAT ENHANCED RELATIVE TO POINTS A BIT FARTHER N AS A
RESULT OF STRONGER WLY FLOW ALOFT NEAR MAIN AXIS OF SRN STREAM JET. 
IN ADDITION...THIS REGION WILL HAVE ACCESS TO SOMEWHAT GREATER
BOUNDARY LAYER MOISTURE /AVERAGE DEWPOINTS IN THE MID TO UPR 50S/
AND WILL BE FARTHER REMOVED FROM ZONE OF STRONGEST POST-IMPULSE
SUBSIDENCE THAT MAY AFFECT PARTS OF KS.

COMBINATION OF STRONG SURFACE HEATING...STEEP MID LEVEL LAPSE RATES
AND DESTABILIZING INFLUENCE OF SRN STREAM DISTURBANCES SHOULD BOOST
MEAN AFTERNOON MLCAPE TO AOA 1500 J/KG.  COUPLED WITH 25-30 KT DEEP
WNWLY SHEAR...SETUP SHOULD SUPPORT WIDELY SCATTERED SUSTAINED
STORMS/SUPERCELLS POSING A THREAT FOR LARGE HAIL/HIGH WIND.  THIS
ACTIVITY MAY ONCE AGAIN MERGE INTO A SHORT BAND OR TWO OF FORWARD
PROPAGATING CLUSTERS THAT WOULD EXTEND A DIMINISHING THREAT FOR
SEVERE EWD INTO PARTS OF WRN OK AND NW TX.

...SW/S CNTRL TX...
THUNDERSTORMS NOW PRESENT OVER THE DAVIS MTNS AND BIG BEND REGION
APPEAR TO BE SUPPORTED BY WEAK...MODERATELY MOIST UPSLOPE FLOW AHEAD
OF LOW AMPLITUDE DISTURBANCE IN THE SUBTROPICAL JET.  THE CONVECTION
MAY SPREAD/REDEVELOP E INTO PARTS OF S CNTRL TX LATER TODAY AS
FORCING FOR ASCENT MOVES EWD.  WHILE BOUNDARY LAYER MOISTURE
INCREASES WITH E/SEWD EXTENT...THE STORMS WILL LIKELY BECOME
INCREASINGLY ELEVATED WITH TIME.  LIMITED DEGREE OF ELEVATED CAPE
SHOULD PRECLUDE A THREAT FOR SEVERE.

...CNTRL PLNS TO MID/LWR MO VLY...
A BAND OF FORCED ASCENT ASSOCIATED WITH NRN KS/SRN NEB VORT MAX WILL
TRACK NE ACROSS THE LWR MO VLY TODAY.  BACKING OF MID AND UPPER
LEVEL FLOW AHEAD OF THIS FEATURE WILL WEAKEN DEEP SHEAR.  AT THE
SAME TIME...MID/UPPER LEVEL CLOUD FIELD ASSOCIATED WITH THE VORT
WILL LIMIT SURFACE HEATING/LOW LEVEL DESTABILIZATION.  A BAND OF
DIURNALLY-ENHANCED STORMS WILL LIKELY PRECEDE AND POSSIBLY ACCOMPANY
UPPER VORT...AND EMBEDDED CELLS COULD YIELD MARGINALLY SEVERE HAIL. 
BUT COMBINATION OF MODEST...LARGELY UNIDIRECTIONAL CLOUD LAYER SHEAR
AND LIMITED SBCAPE /LESS THAN 1000 J PER KG/ SUGGEST THAT THREAT FOR
SUSTAINED SEVERE WILL REMAIN LIMITED.

LATER THIS AFTERNOON...ADDITIONAL STORMS MAY FORM OVER NRN KS AND/OR
SRN NEB...AS SURFACE HEATING UPSTREAM PROMOTES SUBSTANTIAL
DESTABILIZATION ON SWRN EDGE OF VORT-INDUCED PRECIPITATION AREA. 
DEGREE OF POTENTIAL SBCAPE /AROUND 2000 J PER KG/ AND DEEP SHEAR
/35+ KTS/ WOULD SUPPORT SUPERCELLS WITH LARGE HAIL.  HOWEVER... SOME
DOUBT EXISTS AS TO WHETHER OR NOT POST-VORT MAX SUBSIDENCE WILL IN
FACT PRECLUDE SUCH DEVELOPMENT.

MORE LIKELY...NOCTURNAL STRENGTHENING OF THE LLJ WILL RESULT IN A
NEW ROUND OF STORM DEVELOPMENT INVOF THE VORT TONIGHT/EARLY TUESDAY
AS PARCELS ARE ISENTROPICALLY LIFTED OVER RESIDUAL LOW LEVEL COLD
POOL.  THIS ACTIVITY MAY YIELD SEVERE HAIL OVER SRN/ERN NEB AND
ADJACENT PARTS OF FAR NRN KS/NW MO AND WRN IA GIVEN STRENGTH OF MASS
FLUX AND DEGREE OF ELEVATED CAPE /LIKELY ABOVE 500 J PER KG/. 
PATTERN MAY ALSO SUPPORT ECHO TRAINING/UPWIND DEVELOPMENT OF STORMS.

...ND/NRN MN...
CAPPING WILL LIKELY PRECLUDE STORM DEVELOPMENT ALONG COLD FRONT
CROSSING ND/MN THROUGH THE DAY TODAY.  STORMS...HOWEVER...COULD
DEVELOP ALONG AND BEHIND FRONT TONIGHT AS ENTRANCE REGION OF
MANITOBA SPEED MAX OVERSPREADS AREA.  SUFFICIENT ELEVATED CAPE WILL
EXIST FOR HAIL IN ANY STRONGER STORMS THAT DO FORM.  BUT GIVEN THAT
BULK OF LLJ MAX INFLUX WILL BE INTERCEPTED BY SRN STREAM VORT OVER
ERN NEB/IA...POTENTIAL FOR SEVERE HAIL IN ND/MN SHOULD REMAIN
LIMITED.

..CORFIDI/JEWELL.. 04/18/2005

...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.