[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 231229
SWODY1
SPC AC 231227

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0727 AM CDT MON AUG 23 2004

VALID 231300Z - 241200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 10 WNW
RRT 40 NE RWF 15 NW FOD 15 NNW OMA 10 ESE GRI 45 S EAR 35 W P28 15
NNW LBL 45 SSW MHN 25 NNW PHP 20 WNW DIK 55 NNE ISN.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 SSE P07 35 NNE DHT
25 NNE AKO CYS 45 NE U28 45 SSE ELY 25 WSW NFL 50 SW 4LW 15 NNE BLI
...CONT... 45 NE ELO 50 ENE GRB 50 SE OSC ...CONT... 40 ENE ROC UCA
30 NNE POU 30 N TTN 25 SE FDY 30 ESE DAY 20 N HTS 15 W DAN 15 ESE
ILM.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 SE YUM 25 SW PRC
25 NW INW 60 W GUP 40 SSW GNT 20 SE FHU.

...THERE IS A SLGT RISK OF SVR TSTMS FROM WRN/CNTRL KS NWD INTO THE
NRN PLAINS...

...NRN PLAINS...
PROFILERS AND WATER VAPOR IMAGERY SHOW A NEGATIVE-TILT H7-H5
SHORTWAVE TROUGH MIGRATING NEWD THROUGH CNTRL ND-ERN SD-NWRN IA WITH
ASSOCIATED CONVECTION. THIS IS EXPECTED TO MOVE NEWD INTO A MORE
STABLE AIR MASS ACROSS MANITOBA AND MN LATER THIS MORNING AND NO
SEVERE WEATHER IS EXPECTED.

IN THE WAKE OF THE IMPULSE...SUBSIDENCE/CAPPING WILL LIKELY INCREASE
AS WARM FRONT TRANSLATES NEWD INTO SRN ND AND SWRN MN. MOISTURE
TRANSPORT BENEATH STEEP MID-TROPOSPHERIC LAPSE RATES COUPLED WITH
HEATING WILL CONTRIBUTE TO DESTABILIZATION ALONG/AHEAD OF SHARPENING
LEE-TROUGH/DRYLINE FROM SCNTRL ND-NCNTRL NEB.  INHIBITION SHOULD
WEAKEN WITH HEATING AND APPROACH OF STRONGER H5 HEIGHT FALLS
ASSOCIATED WITH UPSTREAM ROCKIES TROUGH AND TSTMS SHOULD INITIATE BY
MID-LATE AFTERNOON.

0-6KM VERTICAL SHEAR WILL INCREASE GRADUALLY DURING THE LATE PART OF
THE AFTERNOON AND POTENTIAL FOR TSTMS TO GROW INTO SUPERCELLS WILL
EXIST GIVEN FAVORABLE INSTABILITY.  STRONGEST SIGNAL FOR LARGE
HAIL/DAMAGING WINDS WILL BE VCNTY DEVELOPING SURFACE TRIPLE POINT
NEAR THE MO RVR IN ND/SD.  THERE WILL BE CONSIDERABLE 0-1KM STORM
RELATIVE HELICITY ACROSS PARTS OF CNTRL SD/ND VCNTY THE WARM
FRONT/LOW.  HOWEVER...FORECAST SOUNDINGS SUGGEST THAT THE LFCS WILL
BE AOA 2200 M AGL...MARGINAL FOR TORNADOES.

ACTIVITY WILL MOVE ENEWD TOWARD THE RED RVR VLY AND WRN MN OVERNIGHT
WITH LOWER SEVERE RISKS GIVEN LOSS OF HEATING.

...CNTRL/SRN PLAINS...
CHALLENGING FORECAST HAS EVOLVED ACROSS THE CNTRL/SRN PLAINS. 
CURRENT MIDLEVEL SHORTWAVE TROUGH CONTINUES TO SLOWLY MOVE EWD
THROUGH KS WITH AN ASSOCIATED TSTM CLUSTER BEING ENHANCED BY A SWLY
LOW LEVEL JET. THE TROUGH AXIS SHOULD REACH THE MO/KS BORDER BY
18Z...BUT ORIENTATION/MAINTENANCE OF THE LOW LEVEL JET WILL MAXIMIZE
THE WARM/MOIST ADVECTION ALONG SWRN EDGE OF THE MCS MOST OF THE DAY.
 THIS IS LIKELY TO FORCE A BUBBLE HIGH TO DEVELOP OVER ERN KS/WRN MO
WHERE CLOUDS SHOULD EXIST ALL DAY...AND REINFORCE A OUTFLOW BOUNDARY
ACROSS THE KS/OK BORDER.  TAIL END OF THIS OUTFLOW WILL LIKELY
REDEVELOP NWWD INTO WCNTRL KS AND LINK UP WITH THE DRYLINE THIS
AFTERNOON.

IT IS NOT CERTAIN IF THE REGION AHEAD OF THE TROUGH ACROSS ERN
KS/WRN MO WILL DESTABILIZE SUFFICIENTLY TO SUPPORT SURFACE BASED
UPDRAFTS.  BUT...ANY POCKETS OF HEATING WOULD LEAD TO A STRONGER
STORM POTENTIAL.  IF THIS SCENARIO UNFOLDS...SBCAPE VALUES WILL
LIKELY BE NEAR 1500 J/KG AND LARGE HAIL OR DAMAGING WINDS WOULD BE
POSSIBLE.  SINCE SO MUCH UNCERTAINTY EXISTS...WILL MAINTAIN LOW
PROBABILISTIC SEVERE AND NOT UPGRADE ATTM.

FARTHER WEST...AIR MASS WILL LIKELY HEAT MORE. HIGH LEVELS REMAIN
DIFFLUENT OWING TO SUBTROPICAL JET ARCING ANTICYCLONICALLY THROUGH
THE SRN PLAINS.  THUS...MAGNITUDE OF RIDGING/SUBSIDENCE BEHIND
CURRENT TROUGH MAY NOT BE STRONG ENOUGH TO RULE OUT TSTM INITIATION
ALONG THE DRYLINE/OUTFLOW INTERSECTION.  MLCAPES COULD APPROACH 3000
J/KG ACROSS SWRN NEB SWD INTO WRN/CNTRL KS BY MID-AFTERNOON AND
COMBINED WITH 30-35 KT SHEAR IN THE LOWEST 6KM...SUPERCELLS WILL BE
POSSIBLE.  EXPERIMENTAL HAIL ALGORITHMS GIVE VERY LARGE HAIL OVER
PARTS OF CNTRL KS...BUT CONFIDENCE ON MORE THAN ISOLD COVERAGE IS
NOT HIGH.  LATER OUTLOOKS WILL HAVE TO ADDRESS ADDING SIGNIFICANT
SEVERE PROBABILITIES.

..RACY/CROSBIE.. 08/23/2004

...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.