[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 291240
SWODY1
SPC AC 291236

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0736 AM CDT SAT MAY 29 2004

VALID 291300Z - 301200Z

THERE IS A HIGH RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 50 S
RSL 25 SW RSL 30 N HLC 25 SSE BBW 30 ENE BUB 20 ESE OFK 20 SSW OMA
20 WNW STJ 40 ENE CNU 50 SW JLN 45 W MKO 35 SE OKC 35 N FSI 50 S
RSL.

THERE IS A MDT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM LTS 35
E GAG 50 SW RSL 25 WSW HLC 30 NNE MCK 25 N BUB 15 E HON 40 NNE ATY
35 WSW STC 30 NNE MKT 30 WSW MCW 10 SE DSM 45 NNE SZL 10 SSW SGF FSM
10 ENE DUA 20 ESE SPS LTS.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 40 N
CMX 45 SSW IMT 35 SSW RFD 55 NNW POF 45 NNW LIT 25 NW TYR 40 NW HDO
20 NNW DRT 45 ENE P07 55 S BGS 30 S CDS 15 S GAG DDC 35 NNW GCK 30
NE LAA 25 SSW LIC 45 WSW AKO 20 NE AIA 20 NNW PHP 30 SSW P24 80 NW
MOT.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 SE P07 25 NNE BGS
10 SW CDS 40 NW GAG 35 WSW GCK 35 S LAA 10 E RTN 30 NNW SAF 30 WNW
GUP 10 NNW GCN SGU 45 NE ELY 55 WSW MLD 15 WNW PIH 55 SW 27U 40 S
S80 30 SSW LWS 10 SW GEG 45 NE GEG 65 NNW 3TH 40 SSE FCA 10 N BZN 25
SSW BIL 65 ENE BIL 35 NW MLS 60 NNW GGW ...CONT... 10 SE PLN 20 SW
HTL 25 ENE GRR 35 SSE FDY 25 SSW MGW 35 SSW WAL ...CONT... 15 NNW
DAB 50 NW AYS 45 SSW ANB 45 ENE GWO 35 SE TXK 30 SW TYR 40 NNW CLL
40 NW LRD.

...THERE IS A HIGH RISK OF SVR TSTMS FROM CNTRL OKLAHOMA TO
SOUTHEAST NEBRASKA...

...THERE IS A MDT RISK OF SVR TSTMS SURROUNDING THE HIGH RISK AREA
FROM THE RED RIVER OF SRN OKLAHOMA TO SWRN MINNESOTA...

...THERE IS A SLGT RISK OF SVR TSTMS FROM SWRN TX TO THE NRN
PLAINS/UPPER MISSISSIPPI VALLEY...

...SIGNIFICANT SEVERE WEATHER OUTBREAK LIKELY OVER PARTS OF THE
SOUTHERN AND CENTRAL PLAINS THIS AFTERNOON AND TONIGHT...

...LARGE CITIES IN AND NEAR THE HIGH RISK AREA INCLUDE OMAHA AND
LINCOLN, NEBRASKA...TOPEKA AND WICHITA, KANSAS...TULSA AND OKLAHOMA
CITY, OKLAHOMA...

...A FEW STRONG, LONG-TRACK TORNADOES, LARGE DESTRUCTIVE HAIL, AND
DAMAGING WINDS WILL BE POSSIBLE IN PARTS OF THE HIGH AND MDT RISK
AREAS FROM THIS AFTERNOON INTO THE EVENING...

MORNING WATER VAPOR SATELLITE IMAGERY SHOWS A STRONG AND PROGRESSIVE
UPPER TROUGH OVER THE WEST WITH SEVERAL WELL-DEFINED SPEED MAXIMA
ROTATING THROUGH THE LARGER SCALE TROUGH. A LEAD IMPULSE...NOW
EMERGING FROM THE SRN HIGH PLAINS...WILL EJECT ENEWD ACROSS
KS/OK/MO/AR OVER THE NEXT SEVERAL HOURS. A STRONGER UPSTREAM
IMPULSE...NOW OVER THE LOWER CO RIVER VALLEY...WILL DRIVE THE MAIN
UPPER TROUGH EAST ACROSS THE HIGH PLAINS LATER THIS AFTERNOON WITH
LARGE 60-90M 12-HOUR HEIGHT FALL CENTER SPREADING ACROSS THE CNTRL
AND NRN PLAINS THOUGH TONIGHT. IN RESPONSE TO THE LARGE SCALE
DYNAMIC FORCING FOR ASCENT...A PRIMARY SURFACE LOW AND INVERTED
TROUGH WILL MOVE ACROSS THE DAKOTAS THROUGH TODAY WHILE A SECONDARY
LOW INTENSIFIES NEAR DRYLINE/COLD FRONT TRIPLE POINT ON THE NEB/KS
BORDER. DRYLINE WILL BECOME ESTABLISHED SOUTH OF THE TRIPLE POINT
LOW...FROM WCNTRL KS/SCNTRL NEB...INTO SWRN OK...AND ACROSS WEST TX.
AS TRIPLE POINT LOW MOVES EAST THROUGH EVENING... A COLD FRONT WILL
DEVELOP SOUTH ACROSS WRN KS AND THE DRYLINE WILL SURGE EAST ACROSS
CNTRL KS/OK AND NCNTRL TX.

...SCNTRL NEB TO CNTRL OK...
SCATTERED...MOSTLY NON-SEVERE...TSTMS SHOULD DEVELOP THIS MORNING AS
LEAD IMPULSE MOVES ACROSS ERN OK AND INTO THE OZARKS. STRONG HEATING
IN THE WAKE OF THIS LEAD IMPULSE WILL DEVELOP ALONG THE DRYLINE BY
EARLY AFTERNOON RESULTING IN A VERY UNSTABLE WARM SECTOR WITH MLCAPE
VALUES OF 3500-4000 J/KG. MODEST CONFLUENT LOW LEVEL FLOW COUPLED
WITH LARGE SCALE HEIGHT FALLS ATOP THE DRY LINE WILL PROVE
SUFFICIENT TO LOCALLY OVERCOME CAPPING INVERSION AND PROMPT
POTENTIALLY EXPLOSIVE SUPERCELL DEVELOPMENT FROM SCNTRL NEB INTO
SWRN OK. FORECAST SOUNDINGS SHOW STRONG LOW LEVEL SHEAR FAVORING
TORNADOES. DIRECTIONAL AND SPEED SHEAR AND TORNADO POTENTIAL WILL
FURTHER INCREASE FROM LATE AFTERNOON INTO THE EVENING AS SLY 850MB
FLOW OF 40-45KT IS TOPPED BY WLY 500MB FLOW OF 50-60KT AND DRYLINE
MIXES EWD INTO LOW LEVEL MOIST AXIS. PERPENDICULAR ORIENTATION OF
THE DEEP LAYER SHEAR VECTOR TO THE DRYLINE...AND INITIALLY STRONG
INHIBITION...WILL ACT TO MAINTAIN DISCRETE CELLS INTO THE EARLY
EVENING FROM KS SOUTH TO THE RED RIVER. STRONGER INHIBITION WITH SWD
EXTENT ALONG THE DRYLINE WOULD SUGGEST MORE ISOLD...BUT STILL
POTENTIALLY SIGNIFICANT...ACTIVITY FROM CNTRL OK INTO TX.

FROM CNTRL OK INTO SERN KS...AN AREA OF HIGHER LONG-TRACK TORNADO
POTENTIAL MAY EXIST INVOF FAVORABLY ORIENTED DIFFERENTIAL
HEATING/OUTFLOW BOUNDARIES LEFT IN THE WAKE OF MORNING CONVECTION
AND CLOUD COVER. ANOTHER AREA FAVORABLE FOR MORE PERSISTENT
SUPERCELLS AND TORNADOES WILL OBVIOUSLY BE NEAR THE TRIPLE POINT LOW
ACROSS NRN/NERN KS. STRONG TORNADOES ARE LIKELY TO BE ASSOCIATED
WITH THESE FEATURES DURING THE LATE AFTERNOON AND EVENING HOURS.
LARGE DESTRUCTIVE HAIL AND DAMAGING DOWNDRAFTS WILL ALSO BE POSSIBLE
WITH ANY SUPERCELL STORM.

ETA RUN FROM 06Z AND 00Z 4KM WRF APPEAR TO SUGGEST A RELATIVE
MINIMUM IN TSTM POTENTIAL FROM PARTS OF ERN KS INTO NWRN MO FROM
LATE AFTERNOON INTO THE EVENING. IT IS NOT UNCOMMON FOR THESE TYPES
OF OUTBREAKS TO EXHIBIT A BIMODAL PATTERN IN SIGNIFICANT SEVERE
WEATHER WITH ONE CONCENTRATED AREA OF STORMS NEAR THE EXIT REGION OF
MID/UPPER JET...AND THE SOUTHERN AREA NEAR THE ENTRANCE REGION OF
THE JET. WHILE THIS SCENARIO MAY INDEED UNFOLD LATER TODAY...THERE
IS INSUFFICIENT EVIDENCE TO SUPPORT DIVIDING THE HIGH RISK AREA INTO
TWO AREAS AT THIS TIME.

...NERN NEB/ERN SD/IA AND MN...
STRONGLY DIFFLUENT MID/UPPER LEVEL FLOW IS ALREADY SPREADING ACROSS
THE CNTRL AND NRN PLAINS THIS MORNING WITH CONSIDERABLE CLOUD COVER
NOTED ON SATELLITE IMAGERY OVER PARTS OF NEB AND THE DAKOTAS.
HOWEVER...VERY STEEP MID LEVEL LAPSE RATES AND MODEST LOW LEVEL
MOISTURE ACROSS THE REGION SHOULD RESULT IN INCREASING
DESTABILIZATION IN THE WAKE OF MCS NOW MOVING ACROSS THE UPPER MS
VALLEY. WHILE STRONG CAPPING/INHIBITION IS NOTED ON FCST SOUNDINGS
ACROSS THE MO RIVER VALLEY THROUGH THE AFTERNOON...DIURNAL HEATING
AND FORCING NEAR COLD FRONT OVER NWRN NEB...AND SURFACE LOW/WARM
FRONT OVER ERN SD...WILL BE SUFFICIENT TO ERODE THE CAP AND PROMOTE
VIGOROUS CONVECTIVE DEVELOPMENT IN THESE AREAS BY LATE AFTERNOON.
CONVECTION WILL THEN DEVELOP EWD INTO GREATER INSTABILITY THROUGH
THE EVENING.

DEEP LAYER SHEAR ACROSS THE MIDDLE MO RIVER VALLEY IS FCST TO BE
SOMEWHAT MARGINAL FOR SUPERCELLS GIVEN WEAK MID LEVEL FLOW WITHIN
THE TROUGH AXIS. HOWEVER...ENHANCED SFC-1KM SHEAR NEAR THE SURFACE
LOW AND WARM FRONT...IN ADDITION TO STRONG MESOSCALE FORCING AND
ABUNDANT INSTABILITY...SHOULD FAVOR AT LEAST A COUPLE OF TORNADIC
STORMS IN ADDITION TO A FEW VERY LARGE HAIL EVENTS. ACTIVITY IS
LIKELY TO CONGEAL INTO ONE OR TWO LARGER CONVECTIVE SYSTEMS FROM WRN
MN INTO NWRN IA DURING THE EVENING WITH AT LEAST A MARGINAL HAIL
THREAT EXTENDING EWD ACROSS THE UPPER MS VALLEY INTO EARLY SUNDAY
MORNING.

..CARBIN/TAYLOR.. 05/29/2004

...NOTICE...
FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.