Friday, May 11, 2007

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 111258
SWODY1
SPC AC 111255

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0755 AM CDT FRI MAY 11 2007

VALID 111300Z - 121200Z

..NO SVR TSTM AREAS FORECAST...

..SYNOPSIS...
LATE SPRING PATTERN IN PLACE ACROSS THE LWR 48. RCKYS RIDGE
EXPECTED TO AMPLIFY SLIGHTLY N/NE THIS PERIOD AS SE TX UPR LOW
WEAKENS AND SETTLES E/SE INTO THE NRN GULF. UPR IMPULSE NOW OFF NRN
CA SHOULD CONTINUE NE TO THE ORE CST EARLY SATURDAY. FARTHER
DOWNSTREAM...WEAK DISTURBANCES NOW OVER ERN MT AND THE WRN DAKOTAS
EXPECTED TO PHASE OVER THE UPR MS VLY AS HEIGHTS RISE OVER THE NRN
RCKYS. STILL FARTHER EAST...WEAK POSITIVE TILT TROUGH WILL EXIT NEW
ENGLAND LATER TODAY...LEAVING A TRAILING ARC OF VORTICITY EXTENDING
W/SE ACROSS THE MID ATLANTIC REGION AND OH VLY INTO THE CNTRL PLNS.

AT LWR LEVELS...FEATURES WILL BR WEAK....WITH THE EXCEPTION OF FRONT
EXTENDING FROM THE NRN PLNS ACROSS THE LWR GRT LKS INTO SRN QUEBEC.
THE WRN PART OF THIS BOUNDARY WILL BEGIN TO EDGE NE AS A WARM FRONT
IN MT...WHILE THE ERN PORTION CONTINUES SE AS A COLD FRONT INTO
UPSTATE NY AND NEW ENGLAND. WHILE ADEQUATE MOISTURE WILL BE PRESENT
FOR DEEP CONVECTION ACROSS MUCH OF THE LWR 48... MOISTURE
AVAILABILITY WILL NOT BE HIGH BY MID-MAY STANDARDS.

..LWR MS VLY/OZARKS/OK...
HEATING BENEATH LINGERING COLD POOL ASSOCIATED WITH DEPARTING UPR
LOW WILL YIELD MODERATE INSTABILITY FROM E TX INTO THE LWR MS VLY.
A SEPARATE AREA OF STORMS MAY FOCUS INVOF TRAILING VORTICITY LOBE
AND WEAK SFC FRONT ACROSS THE MO OZARKS INTO OK. WHILE SHEAR WILL
BE WEAK...THERMODYNAMIC SETUP WILL SUPPORT SCTD BANDS/CLUSTERS OF
PULSE SEVERE STORMS WITH AN ASSOCIATED THREAT FOR LOCALLY DAMAGING
WIND/HAIL THIS AFTERNOON THROUGH EARLY EVENING.

..INTERIOR NW/NRN ROCKIES...
BELT OF MODERATE ANTICYCLONIC FLOW ON FRINGE OF RCKYS RIDGE WILL
MAINTAIN 40+ KT SW TO WLY SHEAR ACROSS PARTS OF NRN ID/MT. WITH
LARGE SCALE ASCENT REMAINING WEAK...INITIATION WILL BE DRIVEN
PRIMARILY BY TERRAIN. GIVEN STRENGTH OF SHEAR AND STEEP LOW LEVEL
LAPSE RATES...POTENTIAL WILL EXIST FOR ISOLATED ACTIVITY WITH GUSTY
WINDS THIS AFTERNOON AND EARLY TONIGHT.

..SD/NRN NEB...
MID-LEVEL VORT MAX/JET STREAK AMPLIFYING E/SE TOWARD THE UPR MS VLY
WILL ENHANCE ASCENT ACROSS THE NRN PLAINS THIS AFTERNOON. DESPITE
LIMITED BOUNDARY-LAYER MOISTURE...STEEP MID-LEVEL LAPSE
RATES AND DAYTIME HEATING SHOULD BOOST MUCAPE TO AROUND 1000 J/KG.
CONVERGENCE ALONG AFOREMENTIONED FRONT IN SD AND/OR ALONG LEE TROUGH
EXTENDING SW INTO WRN NEB MAY SUPPORT ISOLATED STORM DEVELOPMENT BY
LATE AFTERNOON. THOUGH COVERAGE SHOULD REMAIN SPARSE...THOSE THAT
DO FORM WILL HAVE SUFFICIENT SHEAR/INSTABILITY TO BECOME SUSTAINED
AND POSSIBLY YIELD HAIL/LOCALLY-DAMAGING WIND.

.CORFIDI/JEWELL.. 05/11/2007

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@PO.UIUC.EDU with
"unsub wx-storm" in the body of your message. For more information write chris@lib.siu.edu.

No comments: