[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 110630
SWOMCD
SPC MCD 110629 
NCZ000-TNZ000-SCZ000-GAZ000-KYZ000-ALZ000-111030-

MESOSCALE DISCUSSION 0134
NWS STORM PREDICTION CENTER NORMAN OK
1229 AM CST SAT FEB 11 2006

AREAS AFFECTED...ERN TN...FAR NRN AL...FAR NRN GA...AND FAR WRN NC

CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION 

VALID 110629Z - 111030Z

PRECIPITATION WILL GRADUALLY CHANGE FROM RAIN TO SNOW FROM WEST TO
EAST OVERNIGHT...WITH AN INCREASING RATE OF CHANGE TOWARDS 12Z.
MODERATE/LOCALLY HEAVY SNOW SHOULD DEVELOP OVER PORTIONS OF THE
SMOKY AND SOUTHERN APPALACHIAN MOUNTAINS TOWARDS 12Z. SNOWFALL RATES
IN THIS AREA MAY REACH 1 IN/HR.

UPPER AIR ANALYSIS DEPICTED A LARGE AREA OF UPPER-LEVEL DIFFLUENCE
BY WAY OF A COUPLED JET STRUCTURE OVER THE LOWER MS VALLEY AND
SOUTHEAST. THIS UPPER-LEVEL DIFFLUENCE WILL CONTINUE OVERNIGHT
PROVIDING BROAD UPWARD MOTION OVER THE REGION. SATELLITE IMAGERY
SHOWED A BAROCLINIC LEAF AND THE SURFACE ANALYSIS DEPICTED AN
INVERTED TROUGH AXIS RUNNING NORTH-TO-SOUTH FROM CENTRAL AL INTO
MIDDLE TN. TO THE LEFT OF THIS TROUGH...LIGHT LOW-LEVEL FLOW WILL
MAINTAIN WEAK COLD AIR ADVECTION DURING THE EARLY MORNING. TOWARDS
12Z...AS THE SURFACE LOW LIFTS NORTHEAST...LOW-LEVEL COLD AIR
ADVECTION SHOULD ACCELERATE ACROSS FAR NRN AL AND ERN TN.

FARTHER TO THE EAST...RUC/ETA/GFS MODELS INDICATE A LOW-LEVEL JET
AXIS PUNCHING NORTH THROUGH GA BY 12Z. EVEN THOUGH THE MAJORITY OF
WARM THETA-E ADVECTION WILL REMAIN MAINLY SOUTH OF THE REGION...SOME
OF THIS WILL PUSH INTO THE SRN APPALACHIANS/SMOKY MTN REGION TOWARDS
12Z. THIS COMBINED WITH THE BROAD UPPER-LEVEL DIFFLUENCE SHOULD
PROMOTE ENOUGH LIFT TO COOL THE THERMODYNAMICAL PROFILES IN THESE
AREAS TO CHANGE RAIN TO ALL SNOW. SNOWFALL RATES MAY APPROACH 1
IN/HR IN THESE HIGHER ELEVATIONS AROUND 12Z.

..GRAMS.. 02/11/2006

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...GSP...MRX...JKL...FFC...OHX...HUN...

36598385 36298544 35328678 34448735 34568543 34858323
35998187 36498265 

WWWW