[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 221225
SWODY1
SPC AC 221224

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0724 AM CDT FRI OCT 22 2004

VALID 221300Z - 231200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM EMP 30
WNW OMA 30 N YKN 55 WNW AXN 30 NNW BRD 40 SW IWD MSN ALN JBR PBF 30
W JCT 30 SSE BGS 35 SSW LTS EMP.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 E ANJ EVV 40 E MEM
35 ENE MEI 25 SSW CEW ...CONT... 35 SW GPT 10 NE ESF 20 WNW LFK 50
SE SAT 10 SSE LRD ...CONT... 75 SW GDP 50 WNW LBB 50 SSW GAG 25 ENE
P28 25 SE CNK 30 WSW BIE 30 SSW HSI 25 WNW HLC 40 WSW GLD 25 NNE LHX
45 SSW PUB 50 S GUC 25 W MTJ 45 W CAG RWL 40 SE 81V 20 WNW JMS 35
ESE RRT.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 10 SW FMY 35 E ORL.

...THERE IS A SLGT RISK OF SVR TSTMS TODAY THROUGH TONIGHT ACROSS
PARTS OF THE PLAINS AND MISSISSIPPI VALLEY....

HIGH AMPLITUDE UPPER FLOW REGIME PREVAILS ACROSS THE U.S...WITH
SHARP RIDGE EXTENDING FROM THE MEXICAN GULF COAST INTO THE UPPER
GREAT LAKES AND PORTIONS OF THE EASTERN CANADIAN PROVINCES. 
UPSTREAM TROUGH EXTENDS ALONG AN AXIS FROM BAJA INTO THE LEE OF THE
CANADIAN ROCKIES.  THIS FEATURE IS COMPOSED OF A COUPLE OF DISTINCT
SHORT WAVE TROUGHS...MOST SIGNIFICANT OF WHICH THIS FORECAST PERIOD
IS PROGGED TO LIFT OUT OF THE CENTRAL/SOUTHERN GREAT BASIN INTO THE
UPPER MISSISSIPPI AND MID/LOWER MISSOURI VALLEYS.  MODELS SUGGEST
THIS WILL OCCUR AS ANOTHER SHORT WAVE TROUGH DIGS FROM THE NORTHEAST
PACIFIC ACROSS THE BRITISH COLUMBIA COAST.

IN RESPONSE TO EVOLVING UPPER FLOW PATTERN...AND ASSOCIATED
LOW-LEVEL CYCLOGENESIS FROM THE NORTH CENTRAL PLAINS INTO THE UPPER
MISSISSIPPI VALLEY...SUBSTANTIAL INCREASE IN CONVECTIVE DEVELOPMENT
IS EXPECTED ACROSS A FAIRLY BROAD AREA OF THE CENTRAL U.S. TODAY. 
TONGUE OF 60S/70S DEW POINTS RETURNING TO THE WEST OF RETREATING
EASTERN U.S. SURFACE RIDGE WILL CONTRIBUTE TO INSTABILITY SUPPORTING
THIS ACTIVITY. HOWEVER...DUE TO WARMTH OF MID-LEVEL ENVIRONMENT
BENEATH UPPER RIDGE...AND EXTENSIVE HIGH CLOUD COVER ASSOCIATED WITH
UPPER JET TO THE WEST OF RIDGE AXIS...AREAL COVERAGE OF SIGNIFICANT
DESTABILIZATION APPEARS LIKELY TO BE LIMITED.  THIS IS EXPECTED TO
BE A LIMITING FACTOR WITH REGARD TO EXTENT/INTENSITY OF SEVERE
THREAT TODAY.

...EASTERN NEBRASKA/SOUTH DAKOTA INTO WESTERN MINNESOTA/IOWA...
MID/UPPER 60S DEW POINTS WILL CONTINUE TO SPREAD NORTHWARD TODAY
...AHEAD OF DEEPENING SURFACE LOW THROUGH THE MID MISSOURI VALLEY...
WHERE THERE SHOULD BE SUBSTANTIAL DAYTIME HEATING ON NOSE OF
MID-LEVEL DRY SLOT.  MODELS SUGGEST STRENGTHENING/ STEEPENING
ISENTROPIC ASCENT OF THIS HEATED MOIST AIR MASS WILL OCCUR ALONG
WARM FRONT FROM PARTS OF EASTERN SOUTH DAKOTA INTO SOUTHERN
MINNESOTA BY LATE AFTERNOON...FORCING PARCELS TO LEVEL OF FREE
CONVECTION WITH CAPE ON THE ORDER OF 1000 TO 1500 J/KG.  SUBSEQUENT
DEVELOPMENT IS EXPECTED SOUTHWARD ACROSS PARTS OF WESTERN IOWA...IN
EXIT REGION OF MID/UPPER JET...WHICH WILL CONTRIBUTE TO STRONG
VERTICAL SHEAR PROFILES SUPPORTIVE OF SEVERE STORMS.  A FEW
SUPERCELLS APPEAR LIKELY WITH LARGE HAIL AND ISOLATED TORNADOES
POSSIBLE INTO THE EARLY EVENING HOURS.

...LOWER MISSOURI INTO UPPER MISSISSIPPI VALLEY...
AS UPPER TROUGH SHIFTS EAST OF THE CENTRAL HIGH PLAINS AND TAKES ON
INCREASING NEGATIVE TILT THIS EVENING INTO THE OVERNIGHT
HOURS...STRENGTHENING LARGE-SCALE LIFT IS PROGGED AHEAD OF COLD
FRONT SURGING EAST OUT OF THE PLAINS.  THOUGH LACK OF HEATING ACROSS
THIS AREA DURING THE DAY WILL LIKELY LIMIT STEEPNESS OF LAPSE RATES
AND CAPE...FORCING MAY BE SUFFICIENT TO SUPPORT GRADUAL EVOLUTION OF
SQUALL LINE.  THERMODYNAMIC ENVIRONMENT DOES NOT APPEAR LIKELY TO
BECOME SUPPORTIVE OF LARGE HAIL...BUT CONVECTION WILL ENHANCE
DOWNWARD TRANSFER OF HIGHER MOMENTUM AIR NEAR 40-50 KT SOUTHERLY
LOW-LEVEL JET...AND A FEW DAMAGING WIND GUSTS ARE POSSIBLE.

...NORTH CENTRAL TEXAS INTO THE OZARKS...
VERY MOIST AIR WITH 70F+ DEW POINTS WILL ADVECT NORTHWARD OUT OF
EASTERN TEXAS INTO EASTERN OKLAHOMA AND PARTS OF THE OZARK REGION.
WHILE HEATING WILL CONTRIBUTE TO DESTABILIZATION DURING THE DAY...
MID-LEVEL CAP LIKELY WILL INHIBIT DEEP CONVECTIVE DEVELOPMENT UNTIL
THIS EVENING AS UPPER TROUGH BEGINS TO ACCELERATE EASTWARD ACROSS
THE PLAINS.  IN FAVORABLY SHEARED ENVIRONMENT...ISOLATED SUPERCELLS
ARE POSSIBLE WITH INITIAL DEVELOPMENT...THOUGH PROGGED SOUNDINGS
SUGGEST HAIL THREAT MAY BE FAIRLY LOW DUE TO HIGH FREEZING/WET BULB
ZERO LEVELS.  LATER DURING THE EVENING AND OVERNIGHT
HOURS...SOLIDIFICATION/SOUTHWARD DEVELOPMENT OF PRE-FRONTAL SQUALL
LINE MAY OCCUR ACROSS THE MISSOURI OZARKS INTO NORTHERN TEXAS. THIS
WILL BE ON SOUTHERN PERIPHERY OF UPPER TROUGH...BUT MEAN FLOW FIELDS
SHOULD STILL BE STRONG ENOUGH TO SUPPORT RISK OF DAMAGING WIND GUSTS
IN STRONGEST ACTIVITY.

...CENTRAL HIGH PLAINS...
ALTHOUGH BETTER MOISTURE WILL RETURN EAST OF THE HIGH PLAINS...
HEATING/MID-LEVEL COOLING NEAR/JUST AHEAD OF COLD FRONT WILL
CONTRIBUTE TO STEEP LAPSE RATES ACROSS WESTERN/CENTRAL NEBRASKA BY
LATE AFTERNOON.  THIS LIKELY WILL PROVIDE FAVORABLE ENVIRONMENT FOR
A FEW THUNDERSTORMS WITH SMALL HAIL/GUSTY WINDS...BEFORE ONSET OF
SURFACE COOLING EARLY THIS EVENING.

..KERR/BANACOS.. 10/22/2004

...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.