News and Events

December 15th, 2007

        

SPC MCD # 2225

MESOSCALE DISCUSSION 2225
   NWS STORM PREDICTION CENTER NORMAN OK
   1247 PM CST SAT DEC 15 2007
  
   AREAS AFFECTED...SRN AL...FL PANHANDLE...SWRN GA  
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE  
   VALID 151847Z - 152015Z
  
   DEEP CONVECTION HAS GRADUALLY INCREASED OVER THE NCNTRL GULF OF
   MEXICO INLAND INTO SRN AL/FL PANHANDLE IN ASSOCIATION WITH MARITIME
   TROPICAL AIRMASS...SFC DEW POINTS AOA 70F...THAT IS RETURNING ACROSS
   THIS REGION.  LOW LEVEL WARM ADVECTION APPEARS TO BE PRIMARILY
   RESPONSIBLE FOR MUCH OF THIS DEVELOPMENT WITHIN AN OTHERWISE WEAK
   LAPSE RATE ENVIRONMENT.  GIVEN THE WARM ADVECTION REGIME...SEVERAL
   LONGER-LIVED UPDRAFTS HAVE EXHIBITED ROTATION...MAINLY WITHIN THE
   OFFSHORE ACTIVITY.  ALTHOUGH INCREASING THUNDERSTORM CLUSTERS INLAND
   ARE SOMEWHAT LIMITED REGARDING INSTABILITY...A BROAD ZONE OF
   PRESSURE FALLS IN EXCESS OF 3-4 MB OVER THE LAST TWO HOURS SUGGESTS
   THIS CONVECTION IS EVOLVING WITHIN AN ENVIRONMENT OF FAVORABLE
   CONVERGENCE/ASCENT.  EMBEDDED SUPERCELLS COULD CERTAINLY DEVELOP
   ACROSS THIS REGION...PERHAPS GENERATING ISOLATED SEVERE WIND GUSTS
   OR EVEN A TORNADO.  WILL CONTINUE TO MONITOR FOR A POSSIBLE TORNADO
   WATCH.
  
   ..DARROW.. 12/15/2007
  
  
   ATTN...WFO...TAE...BMX...MOB...

MESOSCALE DISCUSSION 2226

MESOSCALE DISCUSSION 2226
   NWS STORM PREDICTION CENTER NORMAN OK
   0531 PM CST SAT DEC 15 2007
  
   AREAS AFFECTED...AL...FL...GA  
   CONCERNING...TORNADO WATCH 738...
  
   VALID 152331Z - 160130Z
 
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 738 CONTINUES.
   MASS OF VIGOROUS DEEP CONVECTION WILL CONTINUE TO SPREAD ENEWD OVER THE FL PANHANDLE...SOUTHEAST AL...AND SOUTHWEST GA AHEAD OF A POTENT
   LARGE SCALE TROUGH DEEPENING OVER THE LOWER MS VALLEY THIS EVENING.
  
   AT LEAST TWO MESOSCALE FRONTAL WAVES HAVE DEVELOPED AND TRACKED
   NEWD...ROUGHLY ALONG A PFN-DHN-ABY LINE...OVER THE PAST 1-2 HOURS
   BASED ON SURFACE ANALYSIS AND RADAR DEPICTION. THIS SURFACE
   DEVELOPMENT WAS OCCURRING ALONG A SHARP WARM FRONT MARKING THE
   LEADING EDGE OF A MARITIME TROPICAL AIR MASS /TD AROUND 70F/ SURGING
   INLAND FROM THE NERN GULF. THIS MOIST AND WEAKLY UNSTABLE AIR MASS
   CONTINUES TO EXPAND AHEAD OF THE FOCUSED FORCING ASSOCIATED WITH THE MESOLOW AND SQUALL LINE NOW MOVING ACROSS WRN PORTIONS OF TORNADO WATCH 738.  
   STRONGER CELLS EMBEDDED WITHIN THE LARGER CONVECTIVE MASS...AND NEAR AFOREMENTIONED FEATURES...SHOULD CONTINUE TO TRACK NEWD AT 35-50KT ACROSS CENTRAL SECTIONS OF THE WATCH OVER THE NEXT COUPLE OF HOURS.
   PRONOUNCED LOW LEVEL SHEAR IS SITUATED ACROSS THE REGION WITH A SLY LOW LEVEL JET OF 35-40KT TURNING TO SWLY AT 60KT WITHIN 3KM OF THE
   SURFACE. RESULTANT MAGNITUDE OF SRH..IN THE RANGE OF 300-400 M2/S2
   PER LATEST TLH VWP AND CELL MOTION...WILL CONTINUE TO SUPPORT LOW
   LEVEL STORM ROTATION AND POSSIBLE TORNADO POTENTIAL WITH MORE
   PERSISTENT UPDRAFTS.
  
   ..CARBIN.. 12/15/2007
  
  
   ATTN...WFO...JAX...FFC...TAE...BMX...MOB...
  
   31588611 30988628 30198643 29848585 29528528 29598470
   29698408 29778361 29368317 29808290 30258303 30688305
   31118299 31968310 31848393 31978504 31678540