Graphic for MPD #0906
MESOSCALE PRECIPITATION DISCUSSION 0906
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
928 PM EDT SUN OCT 22 2017

AREAS AFFECTED...SOUTHEAST AL...WESTERN FL PANHANDLE

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 230130Z - 230600Z

SUMMARY...INTENSITY/COVERAGE OF EXTREME RAINFALL REDUCING IN TIME
THOUGH ISOLATED FLASH FLOODING REMAINS POSSIBLE IN EARLY
OVERNIGHT.

DISCUSSION...01Z SFC MESOANALYSIS DEPICTS A WEAK SURFACE
INFLECTION OF MCV LIFTING NORTHEAST ACROSS PENSACOLA METRO ALONG
OLD OUTFLOW BOUNDARY THAT CONTINUES TO WASH OUT DUE SOUTH ACROSS
THE CENTRAL GULF.  NORTH OF THE INFLECTION THE NORTHERN PORTION OF
THE OUTFLOW BOUNDARY REINFORCED BY RAIN COOLED AIR ANGLES NORTH
INTO SE AL FROM NDZ TO TOI AND ACTS AS AN IDEAL BOUNDARY FOR
STRONG ISENTROPIC ASCENT FROM 20-30KT MOIST 925MB FLOW.  TEMPS IN
THE MID 70S AND TDS IN THE UPPER 60S/LOW 70S AND WEAK LAPSE RATES
STILL PROVIDE 500-750 J/KG OF MUCAPE TO KEEP SOLID CONVECTIVE
CORES PRODUCING 1.0-1.5"/HR RATES ALONG THIS AXIS WITH VERY SLOW
EASTWARD PROPAGATION OF THE BOUNDARY.  THIS POSES A MORE
INUNDATION STYLE TO POTENTIAL FLOODING OVER THE NEXT FEW HOURS.

STRONG HEIGHT FALLS AND RIGHT ENTRANCE REGION OF ENHANCING
DIFFLUENT JET STREAK ARE TRANSLATING THE BEST UL DIVERGENCE
SUPPORT AS WELL AS THE COLD FRONT FURTHER EAST.  AS SUCH THE WEAK
SURFACE INFLECTION IS EXPECTED TO FURTHER DEEPEN/CONNECT TO THE
BOUNDARY TOWARD 04-05Z...THIS WILL STRENGTHEN LOW LEVEL FLOW AND
CONVERGENCE ALONG THE NORTHEAST SIDE OF THE SFC LOW AS IT LIFTS
NORTHEAST ALONG THE INVERTED TROF. AT THIS INTERFACE STRONGER
ASCENT/MST CONVERGENCE MAY SUPPORT 2-2.5"/HR RATES POSING THE
GREATEST RISK FOR FLASH FLOODING.  EVENTUALLY THE COLD FRONT WILL
ADVANCE EASTWARD LIMITING DURATION OF HEAVY RAINFALL ESPECIALLY
OVER DRIER/HIGHER FFG OVER THE CENTRAL FL PANHANDLE...REDUCING THE
THREAT TO QUICK BURST/HIGH RATES IN SHORT DURATION.  ALL
CONSIDERED FLASH FLOODING IS CONSIDERED POSSIBLE OVER THE NEXT
3-6HRS.  

GALLINA

ATTN...WFO...BMX...MOB...TAE...

ATTN...RFC...SERFC...

LAT...LON   32278604 32048540 31388524 30438529 30038565
            30238609 30358682 30328718 30648731 31268709
            31988666


Last Updated: 928 PM EDT SUN OCT 22 2017