[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 280520
SWODY2
SPC AC 280519

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1219 AM CDT FRI OCT 28 2005

VALID 291200Z - 301200Z

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 70 NW HVR GDV 15 NNW
Y22 PIR 9V9 10 E BKX MSP EAU VOK 10 SE CID OJC EMP AVK CDS 60 W MRF
...CONT... 50 SSW DMN GUP U28 10 SW DPG OWY 20 ENE BKE PDT 25 ESE
DLS 15 NE PDX 60 WSW HQM.

...NO SVR TSTM AREAS FORECAST...

MODELS SUGGEST AMPLIFIED UPPER FLOW PATTERN ACROSS THE U.S. WILL
TRANSITION TOWARD A MORE ZONAL/PROGRESSIVE REGIME LATE TODAY INTO
SATURDAY.  AS THIS OCCURS...MID-LEVEL CYCLONE...STILL EVOLVING TODAY
OVER THE NORTHEASTERN STATES...IS PROGGED TO ACCELERATE EASTWARD OFF
THE NORTH ATLANTIC COAST SATURDAY.  LARGE-SURFACE RIDGE IN ITS WAKE
WILL BE SLOWER TO BREAK DOWN/RETREAT...AND IT APPEARS LIKELY TO
MAINTAIN STABLE ENVIRONMENT EAST OF THE MISSISSIPPI VALLEY.  RIDGE
AXIS EXTENDING FROM HIGH CENTER OVER THE OHIO VALLEY THROUGH THE
WESTERN GULF COAST IS ALSO FORECAST TO REMAIN STRONG.  THIS WILL
PRECLUDE SIGNIFICANT RETURN FLOW OF GULF MOISTURE TO THE PLAINS
THROUGH AT LEAST EARLY SUNDAY.

HOWEVER...SIGNIFICANT WARMING OF LOWER-LEVELS IS PROGGED TO OCCUR BY
SATURDAY FROM THE SOUTHERN ROCKIES/MEXICAN PLATEAU INTO THE PLAINS
STATES AND PARTS OF THE MISSISSIPPI VALLEY.  THIS WILL OCCUR ON
WESTERN PERIPHERY OF SURFACE RIDGE...AHEAD OF BROADENING /LOW
AMPLITUDE CYCLONIC UPPER FLOW WHICH IS EXPECTED TO ENCOMPASS MUCH OF
THE NATION FROM THE PACIFIC COAST INTO THE MISSISSIPPI VALLEY BY
EARLY SUNDAY.  SEVERAL SHORT WAVE TROUGHS EMBEDDED WITHIN THIS
REGIME WILL CONTRIBUTE TO CONVECTIVE POTENTIAL OVER A BROAD AREA
SATURDAY/SATURDAY NIGHT...BUT WITHIN THIS AREA... COVERAGE OF
THUNDERSTORMS IS EXPECTED TO BE RATHER SPARSE.

...PACIFIC NORTHWEST THROUGH NORTHERN HIGH PLAINS...
WHILE COLDEST MID-LEVEL AIRMASS /500 TEMPS AOB -20C/ IS FORECAST TO
SHIFT EAST OF THE PACIFIC COAST EARLY SATURDAY...WEAK MOIST ONSHORE
FLOW IS FORECAST TO PERSIST INTO THE WESTERN SLOPES OF THE CASCADES.
 THIS WILL MAINTAIN WEAK INSTABILITY AND LIKELIHOOD OF OCCASIONAL
ISOLATED THUNDERSTORMS THROUGH THE DAYTIME HOURS.  OTHERWISE...AS
MID-LEVEL THERMAL TROUGH SHIFTS EASTWARD... DESTABILIZATION WILL AID
DEVELOPMENT OF SCATTERED THUNDERSTORMS ACROSS THE NORTHERN
INTERMOUNTAIN REGION/ROCKIES SATURDAY AFTERNOON...POSSIBLY INTO THE
NORTHERN HIGH PLAINS LATE SATURDAY AFTERNOON/EVENING...BEFORE
ACTIVITY DIMINISHES.

...SOUTHERN ROCKIES INTO MISSOURI VALLEY...
MID-LEVELS WILL NOT BE AS COOL...BUT MODELS DO SUGGEST A LIMITED
NORTHEASTWARD RETURN FLOW OF LOW/MID-LEVEL MOISTURE FROM THE
NORTHERN MEXICAN PLATEAU/SOUTHERN ROCKIES.  THIS MAY CONTRIBUTE TO
SCATTERED CONVECTIVE DEVELOPMENT DURING THE DAY SATURDAY ACROSS THE
HIGHER TERRAIN OF NEW MEXICO...AND NEAR LEE SURFACE TROUGH... FROM
EASTERN NEW MEXICO INTO WESTERN KANSAS.  AS THIS ACTIVITY DIMINISHES
SATURDAY EVENING...NEW WEAK STORMS MAY DEVELOP IN STRENGTHENING WARM
ADVECTION REGIME ATOP NOCTURNAL SURFACE INVERSION ACROSS THE CENTRAL
PLAINS/MID MISSOURI VALLEY.

..KERR.. 10/28/2005

...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.