aggiornamento SPC:

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0644 AM CST FRI FEB 23 2007

VALID 231300Z - 241200Z

...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON THROUGH TONIGHT
ACROSS PARTS OF SOUTH CENTRAL KS...WESTERN AND CENTRAL OK...AND
NORTHWEST TX....

...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL NEB INTO CENTRAL
TX...

A VERY COMPLICATED FORECAST SCENARIO IS UNFOLDING FOR THIS AFTERNOON
AND EVENING ACROSS THE SOUTHERN PLAINS. THE OVERALL SYNOPTIC
PATTERN AND TIMING OF SYSTEM SUGGESTS THE THREAT OF A SIGNIFICANT
SEVERE WEATHER EVENT. HOWEVER...ISSUES REGARDING THE THERMODYNAMIC
ENVIRONMENT LESSEN CONFIDENCE IN FORECASTING AN OUTBREAK OF SEVERE
STORMS AND TORNADOES.

MORNING WATER VAPOR LOOP SHOWS STRONG UPPER TROUGH OVER CA/NV. THIS
SYSTEM WILL TRACK EASTWARD AND BEGIN TO AFFECT THE SOUTHERN HIGH
PLAINS BY LATE THIS AFTERNOON AND EVENING. MEANWHILE...
INCREASINGLY STRONG SOUTHERLY LOW LEVEL WINDS ACROSS THE PLAINS
REGION WILL TRANSPORT GULF MOISTURE NORTHWARD THROUGHOUT THE
FORECAST PERIOD...WITH DEWPOINTS IN THE 50S EXPECTED AS FAR NORTH AS
CENTRAL KS BY 24/00Z. COOLING MID LEVEL TEMPERATURES AND STEEPENING
LAPSE RATES WILL HELP TO YIELD AN AXIS OF MLCAPE VALUES OF 500-1000
J/KG ALONG/AHEAD OF SURFACE DRYLINE FROM SOUTH-CENTRAL KS INTO
WESTERN OK AND THE EASTERN TX PANHANDLE. FORECAST SOUNDINGS IN THIS
REGION SHOW A PRONOUNCED CAP DURING THE MORNING THAT SLOWLY ERODES
BY LATE AFTERNOON DUE TO VERTICAL MIXING AND LIFT.

ONE PRIMARY COMPLICATING FACTOR TO THE FORECAST TODAY IS THE LIKELY
DEVELOPMENT OF WIDESPREAD CLOUDS ACROSS THE WARM SECTOR LATER THIS
MORNING. THIS STRATUS DECK AND SCATTERED PRECIPITATION WILL GREATLY
SUPPRESS DAYTIME HEATING ACROSS WESTERN OK...LIMITING AFTERNOON CAPE
VALUES.

PRESENT INDICATIONS ARE THAT ISOLATED SUPERCELL THUNDERSTORMS WILL
DEVELOP ALONG THE DRYLINE FROM NEAR DDC-CDS THIS EVENING BETWEEN
22-02Z. RELATIVELY WEAK MOISTURE VALUES...ANTICIPATED CLOUD
COVER...AND TIMING OF UPPER SYSTEM SUGGEST THAT COVERAGE OF STORMS
COULD BE QUITE LOW. NEVERTHELESS...THOSE ISOLATED STORMS THAT CAN
DEVELOP WILL POSE A THREAT OF LARGE HAIL...DAMAGING WINDS...AND
TORNADOES. FORECAST SOUNDINGS FROM VARIOUS MODELS SUGGEST EFFECTIVE
HELICITY VALUES OF 400-600 M2/S2...ALONG WITH LOW LCL HEIGHTS AND
STRONG DEEP LAYER VERTICAL SHEAR. THERE APPEARS TO BE A PERIOD
PRIMARILY BETWEEN 00-06Z WHEN A CONDITIONAL RISK OF STRONG TORNADOES
AND VERY LARGE HAIL WOULD EXIST ACROSS WESTERN OK...SOUTH CENTRAL
KS... AND NORTHWEST TX.

BY MIDNIGHT...STRONG LARGE SCALE FORCING IS EXPECTED TO MOVE INTO
CENTRAL OK. MORE WIDESPREAD THUNDERSTORM DEVELOPMENT IS LIKELY BY
THIS TIME...WITH ORGANIZATION INTO A SQUALL LINE ANTICIPATED FROM
CENTRAL OK INTO NORTH TX. THESE STORMS MAY REMAIN INTENSE THE
REMAINDER OF THE NIGHT WITH A RISK OF WIDESPREAD WIND DAMAGE AS THEY
APPROACH THE ARKLATEX REGION.


direi ottimo x il mio target