[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 280614
SWODY1
SPC AC 280612

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0112 AM CDT FRI JUL 28 2006

VALID 281200Z - 291200Z

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS MID ATLANTIC...NEW
ENGLAND...

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS WRN/NRN AZ...

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS UPPER MS VALLEY TO WRN
LM...

...SYNOPSIS...
PROGRESSIVE NRN STREAM FLOW WILL CONTINUE THROUGH PERIOD...FEATURING
PRONOUNCED SHORTWAVE TROUGH NOW EVIDENT IN MOISTURE CHANNEL IMAGERY
FROM LM SWWD ACROSS MO.  THIS FEATURE IS FCST TO MOVE EWD ACROSS ERN
GREAT LAKES...MID ATLANTIC AND NEW ENGLAND STATES THROUGH 29/00Z. 
MEANWHILE TROUGH NOW OVER NERN MB AND FAR NRN ONT SHOULD CONTINUE
MOVING EWD OVER JAMES BAY REGION...WHILE ASSOCIATED LOW LEVEL COLD
FRONT MOVES INTO NRN PLAINS.  BY 29/06Z THIS FRONT SHOULD STALL
INVOF ND/SD BORDER AS LEE CYCLONE INTENSIFIES OVER WRN SD.  ANOTHER
DIFFUSE FRONTAL ZONE WILL REMAIN QUASISTATIONARY FROM ERN NM ENEWD
ACROSS OK AND OZARKS REGION...MODULATED ON MESOSCALE LEVEL BY
NUMEROUS OUTFLOW BOUNDARIES.

MEANWHILE...MID-UPPER LEVEL LOW -- WELL DEFINED IN MOISTURE CHANNEL
IMAGERY ATTM OVER NWRN NM -- IS FCST TO DRIFT SWWD OVER ERN
AZ....ENHANCING NELY GRADIENT FLOW AROUND RIM OF NV ANTICYCLONE.

...MID ATLANTIC...NEW ENGLAND...
SCATTERED TSTMS ARE FCST TO DEVELOP IN FAVORABLY MOIST AIR MASS FROM
LATE MORNING THROUGH AFTERNOON...ORGANIZING INTO ONE OR MORE
BANDS/CLUSTERS WHILE MOVING EWD ACROSS REGION. MAIN THREAT WILL BE
DAMAGING WINDS.  HOWEVER...SUFFICIENT VEERING IS EVIDENT IN FCST
HODOGRAPHS FROM ERN PA ACROSS SRN/CENTRAL NEW ENGLAND TO SUPPORT
SUPERCELL MODE WITH ANY RELATIVELY DISCRETE CONVECTION.
MAIN UNCERTAINTY ATTM IS STRENGTH OF DIABATIC HEATING IN ADVANCE OF
CLOUD/PRECIP SHIELD ASSOCIATED WITH ONGOING MCS.  THIS RENDERS
PROGRESSIVELY MORE UNCERTAINTY WITH WWD EXTENT NOW EVIDENT FROM LE
SWWD ACROSS NWRN OH AND INDIANA.

VERTICAL WIND PROFILES AND LOW LEVEL SHEAR EACH ARE EXPECTED TO
WEAKEN WITH SWWD EXTENT ACROSS APPALACHIANS AND OH VALLEY
REGION...FAVORING MORE SPORADIC...PULSE/MULTICELL SEVERE THREAT AND
LOWER PROBABILITIES.

...AZ...
CLOUD COVER NOW EVIDENT OVER PORTIONS NRN/WRN AZ -- RESIDUE FROM
EARLIER CONVECTION -- SHOULD ABATE ENOUGH BY UPCOMING AFTERNOON TO
PERMIT STRONG INSOLATION ACROSS LARGE PORTION OF REGION...W OF APCHG
MID/UPPER LEVEL PERTURBATION.  SFC DEW POINTS REMAINING UPPER 60S TO
LOW 70S F IN DESERTS AND NEAR 60 IN HIGHER ELEVATIONS WILL FURTHER
CONTRIBUTE TO WEAK MID-LATE AFTERNOON CINH AND TSTM POTENTIAL. ATOP
THAT INCREASINGLY UNSTABLE BOUNDARY LAYER...AFOREMENTIONED CORRIDOR
OF ENHANCED MIDLEVEL NELYS WILL ENHANCE DEEP-LAYER SHEAR FAVORING
SOME ORGANIZED SVR THREAT.  POTENTIAL EXISTS FOR TSTMS TO FORM OVER
HIGHER ELEVATIONS AND ORGANIZE INTO OUTFLOW DOMINANT MCS MOVING INTO
WELL MIXED/STRONGLY HEATED BOUNDARY LAYERS OVER DESERTS.  MAIN
THREAT IS DAMAGING WIND...THOUGH ISOLATED HAIL MAY BE A CONCERN WHEN
STORMS ARE STILL FAIRLY DISCRETE.

FARTHER SE ACROSS SERN AND EXTREME E-CENTRAL AZ...AND SWRN NM...MORE
UNCERTAINTIES EXIST REGARDING STRENGTH OF AFTERNOON
DESTABILIZATION...IN WAKE OF MCS DURING DAY THURSDAY AND ANOTHER
COMPLEX NOW MOVING SWWD ACROSS THAT AREA.  FLOW ALOFT ALSO IS
EXPECTED TO BE WEAKER AND LOSE ELY COMPONENT WITH SEWD GEOGRAPHIC
EXTENT....INHIBITING BOTH VERTICAL SHEAR AND PROPAGATION POTENTIAL
ONTO DESERTS FROM ERN PORTIONS MOGOLLON RIM.  THEREFORE SVR
PROBABILITIES ARE KEPT MRGL ATTM.

...UPPER MIDWEST...
SCATTERED TSTMS SHOULD DEVELOP DURING AFTERNOON INTO EARLY EVENING
HOURS...PERHAPS ORGANIZING INTO MCS WITH DAMAGING GUSTS AND LARGE
HAIL POSSIBLE. NEARLY UNIDIRECTIONAL DEEP-LAYER WIND PROFILES ARE
FCST...ALONG WITH MLCAPES SOMETIMES EXCEEDING 2500 J/KG.  THIS
SUPPORTS POTENTIAL FOR STRONG-SEVERE DOWNDRAFTS...GIVEN STRONG SFC
HEATING AND FAVORABLE BOUNDARY LAYER MOISTURE EXPECTED.

AFTER DARK...STRONG LOW LEVEL WAA AND AT LEAST MRGL MOISTURE WILL
SUPPORT POTENTIAL FOR ELEVATED MCS FORMATION ACROSS PORTIONS ND/MN. 
STEEP LAPSE RATES AND FAVORABLE EFFECTIVE SHEARS WILL SUPPORT
POTENTIAL FOR TSTMS TO PRODUCE ISOLATED LARGE HAIL.

...OZARKS TO NW TX...
WIDELY SCATTERED TSTMS ARE EXPECTED TO DEVELOP AGAIN THIS AFTERNOON
INVOF WEAK LOW LEVEL BAROCLINIC ZONE...ESPECIALLY ALONG OUTFLOW
BOUNDARIES AND THEIR INTERSECTIONS.  HOT...DEEPLY MIXED SUBCLOUD
LAYERS WILL PROVIDE THREAT FOR A FEW DAMAGING WIND EVENTS WITH
STRONGEST PULSE/MULTICELLULAR ACTIVITY.  HOWEVER...ORGANIZED SVR IS
NOT ANTICIPATED BECAUSE OF WEAK WINDS/SHEAR AND
OUTFLOW-DOMINANT/SHORT-LIVED NATURE OF ANY GIVEN MULTICELL EVENT. 
SVR POTENTIAL WILL DIMINISH MARKEDLY AFTER SUNSET WHEN DIABATIC
COOLING REMOVES SBCAPE.

..EDWARDS/TAYLOR.. 07/28/2006