Sunday, April 18, 2010

DAY2SVR: Nws Storm Prediction Center Norman Ok

ACUS02 KWNS 181730
SWODY2
SPC AC 181729

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1229 PM CDT SUN APR 18 2010

VALID 191200Z - 201200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
A HIGH AMPLITUDE MID-UPPER LEVEL RIDGE EXTENDING FROM THE CENTRAL
ROCKIES NWD THROUGH THE CANADIAN PRAIRIE PROVINCES TO THE HIGH
LATITUDES IS EXPECTED UNDERGO FURTHER STRENGTHENING DURING THE DAY 2
FORECAST PERIOD. THIS BLOCKING RIDGE WILL MAINTAIN A SPLIT FLOW
REGIME ACROSS THE LOWER 48 STATES INTO THROUGH MONDAY...AND RESULT
IN THE SWD AMPLIFICATION OF A DEEP GULF OF ALASKA CLOSED LOW INTO
THE ERN PACIFIC/WEST COAST. MEANWHILE...LOWER AMPLITUDE TROUGHS ARE
EXPECTED TO TRACK SEWD FROM THE CENTRAL/NRN PLAINS...WITH MODELS
SUGGESTING A MORE PROMINENT IMPULSE AMPLIFIES AS IT APPROACHES THE
TN VALLEY. A COMPACT PACIFIC CLOSED LOW...CURRENTLY CENTERED AT
28N/129W...IS EXPECTED TO DE-AMPLIFY AS IT TRACKS EWD ACROSS NRN
MEXICO TO THE TX BIG BEND REGION ON DAY 2.

IN THE LOW LEVELS...A SURFACE LOW IS EXPECTED TO DEVELOP OVER ERN CO
ALONG THE HIGH PLAINS LEE TROUGH. A SECOND SURFACE BOUNDARY
EXTENDING NWD FROM ERN CO TO WRN SD AT 12Z MONDAY IS EXPECTED TO
MOVE ESEWD...EXTENDING FROM NERN CO TO CENTRAL NEB BY MONDAY
AFTERNOON.

...CENTRAL HIGH PLAINS...
SLY WINDS INTO THE CENTRAL HIGH PLAINS WILL TRANSPORT MOISTURE
NWD...WITH SURFACE DEWPOINTS EXPECTED TO BE IN THE LOWER-MID 40S BY
PEAK HEATING. THIS COMBINED WITH DIABATIC HEATING AND ELEVATED
MIXED LAYER /STEEP LAPSE RATES /8 C/KM/ SPREADING EWD OVER THE
CENTRAL HIGH PLAINS SHOULD RESULT IN MLCAPE 500-1000 J/KG. FORCING
FOR ASCENT ATTENDANT TO A WEAK IMPULSE TRACKING SEWD ACROSS THE
CENTRAL HIGH PLAINS MONDAY AFTERNOON WITHIN NWLY FLOW ALOFT IS
EXPECTED TO SUPPORT TSTM DEVELOPMENT...ESPECIALLY IN VICINITY OF LEE
TROUGH...SECONDARY NEB BOUNDARY AND SURFACE LOW. DESPITE WEAK WINDS
AROUND 700 MB...SOME STRENGTHENING OF SLY FLOW /20-25 KT/ MONDAY
AFTERNOON ALONG ERN PERIPHERY OF DEEPENING ERN CO SURFACE LOW AND
BENEATH INCREASING NWLY MIDLEVEL WINDS /30-35 KT/ WILL RESULT IN
EFFECTIVE BULK SHEAR AROUND 35 KT. THIS SHEAR WILL BE SUFFICIENT
FOR SUPERCELLS WITH A THREAT FOR HAIL AND LOCALLY STRONG WIND GUSTS.
HOWEVER...OVERALL SEVERE WEATHER THREAT WILL REMAIN LOW WITH THIS
OUTLOOK...GIVEN THE RELATIVELY WEAK MOISTURE RETURN LIMITING THE
DEGREE OF INSTABILITY AND HAIL SIZE TO GENERALLY BELOW 1 INCH.

..PETERS.. 04/18/2010

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.

No comments: