[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 280516
SWODY1
SPC AC 280515

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1215 AM CDT SUN AUG 28 2005

VALID 281200Z - 291200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 15 W
BVE 20 ENE MSY 45 NNW GPT 55 N MOB 25 WSW TOI 15 E DHN 35 SSW TLH.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 SW DUG 35 SSW SOW
70 SE PGA 10 N U17 25 ENE CNY DEN MHN 40 NNE BUB 20 NW SUX 30 ESE
OTM 15 WNW COU 35 WNW TUL 30 NE ADM 40 SW PGO 60 E FSM ARG 10 NE CKV
30 N LOZ 10 SE CRW 35 WSW MRB 30 SW IPT 30 NNW SYR.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 W CLE DAY 10 SSW
IND 15 ESE DNV 50 S CGX 20 NE BEH 30 SSW OSC.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 80 WNW FCA 30 NNW S80
20 E BNO 60 W BNO 45 ENE DLS 45 NW 4OM.

...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE CNTRL/ERN
GULF COAST...

...SYNOPSIS...
AMPLIFIED POLAR BRANCH IS FORECAST ACROSS THE NRN HALF OF THE CONUS
THROUGH THE DAY 1 PERIOD WITH PRIMARY FEATURES BEING MID/UPPER LOW
WHICH WILL SLOWLY PROGRESS EWD ACROSS ONTARIO AND INTENSIFYING
TROUGH OVER BRITISH COLUMBIA AND THE PACIFIC NW.  IN THE
LOW-LEVELS...OCCLUDED SURFACE LOW WILL SIMILARLY DEVELOP SLOWLY EWD
ACROSS ONTARIO WITH TRAILING COLD FRONT PROGRESSING EWD THROUGH THE
GREAT LAKES.  WRN EXTENSION OF THIS BOUNDARY IS FORECAST TO REMAIN
QUASI-STATIONARY OVER THE CNTRL PLAINS.  FARTHER TO THE E...INITIAL
FRONTAL SURGE WILL SHIFT EWD THROUGH NEW ENGLAND AND MIDDLE ATLANTIC
STATES...WITH TRAILING PORTION OF THIS BOUNDARY MOVING LITTLE OVER
THE TN VALLEY. OVER THE GULF OF MEXICO...CENTER OF KATRINA IS
FORECAST TO APPROACH THE CNTRL GULF COAST SUNDAY NIGHT.

...CNTRL/ERN GULF COAST...
PER LATEST NHC GUIDANCE...HURRICANE KATRINA IS FORECAST TO TURN MORE
NWLY WITH TIME...WITH CENTER APPROACHING THE CNTRL GULF COAST BY
29/12Z.  AS THIS OCCURS...EXPECT ATTENDANT CONVECTIVE BANDS TO
GRADUALLY OVERSPREAD PORTIONS OF THE CNTRL/ERN GULF COAST.  TROPICAL
AIR MASS AND RESULTANT WEAK TO MODERATE INSTABILITY COUPLED WITH
PROGRESSIVELY STRONGER LOW-LEVEL SHEAR IN ERN SEMI-CIRCLE OF KATRINA
WILL RESULT IN AN ENVIRONMENT FAVORABLE OF MINI SUPERCELLS AND
ISOLATED TORNADOES.

...TN VALLEY...
A SEPARATE REGION OF ISOLATED...DIURNAL SEVERE STORMS IS EXPECTED TO
DEVELOP INVOF STALLED FRONTAL BOUNDARY ACROSS THE TN VALLEY.
HERE...COMBINATION OF MOIST BOUNDARY-LAYER CONDITIONS AND DIABATIC
HEATING IS FORECAST TO CONTRIBUTE TO POCKETS OF MODERATE INSTABILITY
WITH MLCAPES APPROACHING 2000-2500 J/KG.  WHILE LOW TO MID-LEVEL
SHEAR WILL NOT BE PARTICULARLY STRONG...FORECAST HODOGRAPHS DO
INDICATE STRONGER WIND FIELDS ABOVE 9 KM AGL...WHICH SHOULD SUPPORT
SOME STORM ORGANIZATION.  GIVEN RATHER WARM THERMODYNAMIC
PROFILES...IT APPEARS THAT THE PRIMARY SEVERE WEATHER THREAT WILL BE
DAMAGING WINDS RESULTING FROM WET MICROBURSTS AND/OR ORGANIZING
CONVECTIVE COLD POOLS.

...CNTRL/SRN PLAINS...
AFOREMENTIONED...STALLED FRONTAL BOUNDARY AS WELL AS ANY RESIDUAL
OUTFLOW BOUNDARIES WILL PROVIDE THE FOCUS FOR STRONG TO POTENTIALLY
SEVERE STORM DEVELOPMENT THIS AFTERNOON AND EVENING.  DEWPOINTS IN
THE 60S TO LOWER 70S COUPLED WITH RATHER STEEP MID-LEVEL LAPSE RATES
OF AROUND 7.5 C/KM WILL CONTRIBUTE TO MODERATE INSTABILITY LATER
TODAY WITH MLCAPES OF 1500-2500 J/KG.  INSPECTION OF WATER VAPOR
IMAGERY AND LATEST SHORT TERM MODEL GUIDANCE SUGGEST THAT SHORTWAVE
TROUGH OVER SERN MT AND EMBEDDED IMPULSES FROM THE GREAT BASIN INTO
THE CNTRL HIGH PLAINS WILL ACT ON THIS INSTABILITY...SUPPORTING AN
INCREASE IN STORM COVERAGE AND INTENSITY.

FORECAST HODOGRAPHS ACROSS REGION INDICATE VEERING WINDS WITH
HEIGHT...WITH STRONGEST DEEP-LAYER VERTICAL SHEAR RESIDING ACROSS
NRN EXTENT OF INSTABILITY AXIS...IN CLOSER PROXIMITY TO STRONGER
MID/HIGH-LEVEL WIND FIELDS ASSOCIATED WITH ONTARIO LOW.  MOST
INTENSE STORMS WILL BE CAPABLE OF ISOLATED LARGE HAIL AND DAMAGING
WINDS AND A CATEGORICAL SLIGHT RISK MAY BE REQUIRED ACROSS PORTIONS
OF DISCUSSION AREA ONCE MESOSCALE DETAILS BECOME CLEARER.

...LOWER GREAT LAKES...
SOME THREAT OF ISOLATED SEVERE STORMS IS ALSO EXPECTED TO EXTEND
NEWD ALONG COLD FRONT INTO THE CNTRL GREAT LAKES THIS AFTERNOON AND
EVENING.  WHILE LOW-LEVEL MOISTURE WILL BE COMPARATIVELY LESS THAN
POINTS TO THE S...DAYTIME HEATING AND COOLER MID-LEVEL TEMPERATURES
WILL CONTRIBUTE TO STEEPENING LOW/MID-LEVEL LAPSE RATES AND MLCAPES
APPROACHING 1000-1500 J/KG.  LARGELY UNIDIRECTIONAL SWLY WINDS
INCREASING TO 50-60 KTS IN THE MID-LEVELS SUGGEST THE POTENTIAL FOR
A FEW BOWING STRUCTURES CAPABLE OF ISOLATED DAMAGING WINDS.

..MEAD/TAYLOR.. 08/28/2005

...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.