[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 280719
SWODY2
SPC AC 280718

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0118 AM CST MON FEB 28 2005

VALID 011200Z - 021200Z

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 SW MLU ESF 10 SW
LFK 30 E TPL 40 E ABI 55 SE CDS 45 WSW END 35 SSW PNC MKO 25 NNE TXK
20 SW MLU.

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
LARGE TROUGH / LOW AT MID AND UPPER LEVELS WILL CONTINUE AFFECTING
THE ERN CONUS THIS PERIOD...WITH ASSOCIATED SURFACE LOW FORECAST TO
LINGER OVER / INVOF NEW ENGLAND THROUGH THE PERIOD.  IN THE WAKE OF
THIS SYSTEM...COOL / STABLE AIRMASS WILL PERSIST OVER THE ERN HALF
OF THE COUNTRY.  

MEANWHILE...LARGE MID-LEVEL RIDGE WILL REMAIN OVER THE WESTERN
CONUS...THOUGH A SHORT-WAVE TROUGH IS EXPECTED TO MOVE ONSHORE OVER
THE PAC NW LATE IN THE PERIOD INTO THE MEAN RIDGE POSITION.  THOUGH
A FEW LIGHTNING STRIKES MAY AFFECT THE PAC NW LATE AS THIS SYSTEM
MOVES ONSHORE...MAIN THUNDER THREAT IS EXPECTED IN WARM ADVECTION
REGIME FORECAST TO EVOLVE ACROSS THE SRN PLAINS THROUGH THE PERIOD.

...SRN PLAINS...
THOUGH LARGE AREA OF SURFACE HIGH PRESSURE SHOULD PREVAIL AT THE
START OF THE PERIOD FROM THE ROCKIES EWD ACROSS THE PLAINS IN THE
WAKE OF LARGE ERN U.S. SURFACE CYCLONE...PERSISTENT WNWLY FLOW ALOFT
SHOULD INDUCE LEE TROUGHING ACROSS THE HIGH PLAINS -- EFFECTIVELY
BISECTING SURFACE RIDGE.

WITH SURFACE PRESSURE FALLING OVER THE HIGH PLAINS WHILE HIGH
PRESSURE PERSISTS OVER THE ERN PLAINS...RESULTING GRADIENT WILL
FAVOR AN INCREASE IN SLY LOW-LEVEL FLOW ACROSS TX / OK.  THOUGH
BOUNDARY LAYER WILL REMAIN DRY...WARM ADVECTION / ISENTROPIC UPGLIDE
SHOULD RESULT IN LOW-LEVEL MOISTENING -- WITHIN APPROXIMATELY THE
900 TO 800 MB LAYER.  THIS MOISTENING -- BENEATH  STEEPER LAPSE
RATES WITHIN ELEVATED MIXED LAYER ADVECTING ESEWD FROM THE ROCKIES
-- SHOULD CONTRIBUTE TO MARGINAL / PRIMARILY ELEVATED INSTABILITY
ACROSS CENTRAL / N TX INTO OK.

BEST CHANCE FOR SURFACE-BASED STORMS APPEARS TO EXIST DURING THE
LATE AFTERNOON ACROSS CENTRAL AND PERHAPS INTO N TX...WHERE DAYTIME
HEATING MAY ALLOW DEEPLY-MIXED BOUNDARY LAYER TO DEVELOP.  SHOULD
THIS OCCUR...A THREAT FOR LOCALLY DAMAGING WINDS COULD EXIST ALONG
WITH HAIL -- GIVEN INVERTED-V TYPE BOUNDARY LAYER PROFILE AND
MODERATELY-STRONG / VEERING WIND FIELD WITH HEIGHT EXPECTED OVER
THIS REGION.  MORE LIKELY SCENARIO HOWEVER WILL BE THAT STORMS
DEVELOP FROM N TX NWD IN AN ELEVATED LAYER ABOVE PERSISTENTLY COOL /
STABLE BOUNDARY LAYER -- PARTICULARLY AS LOW-LEVEL JET INTENSIFIES
OVERNIGHT.  ALTHOUGH 40 TO 50 KT MID-LEVEL FLOW AND FAIRLY STEEP
LAPSE RATES MAY STILL PROVIDE SUFFICIENT SHEAR / ELEVATED
INSTABILITY COMBINATION FOR HAIL...WILL INTRODUCE ONLY A SMALL AREA
OF LOW / CONDITIONAL HAIL PROBABILITY ATTM DUE TO UNCERTAINTY WITH
REGARDS TO DEGREE OF MOISTENING / DESTABILIZATION WHICH MAY OCCUR.

..GOSS.. 02/28/2005

...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.