000 FXUS62 KMLB 240949 AFDMLB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 448 AM EST TUE NOV 24 2009 ...RAIN CHANCES INCREASE THROUGH WED... ...DRIER AND COOLER AIR MASS ARRIVES THANKSGIVING DAY... .DISCUSSION... TODAY-TONIGHT...OLD FRONTAL BAND EXTENDS ACROSS SOUTH FL EARLY THIS MORNING. SURFACE WAVE DEVELOPING ALONG THE BOUNDARY OVER THE GULF TODAY AND WILL DRIFT TOWARD THE FL PENINSULA THROUGH TONIGHT. INCREASING MOIST SSW-SW FLOW THROUGH THE MID LEVELS WILL ENHANCE THE LIFT OVER THE REGION NEXT 24 HOURS AND POPS WILL INCREASE AS IT DOES SO. HAVE STARTED THIS MORNING OFF DRY BUT INDICATE CHANCE POPS THIS AFTERNOON AND RISING TO GOOD CHANCE (~50) TONIGHT. HAVE ALSO ADDED A THUNDER MENTION FOR ROUGHLY SOUTHERN HALF OF EC FL (OSCEOLA-BREVARD) SWD. THIS GIVEN THE BETTER INSTABILITY AS MAXES REACH LOW-MID 80S VERSUS MID-UPPER 70S NORTH AND CLOSER PROXIMITY OF NORTHWARD DRIFTING SURFACE BOUNDARY. OVERNIGHT MIN TEMPS INTO EARLY WED ONLY FALLING INTO THE UPPER 60S/LOWER 70S GIVEN THE WARM SOUTHERLY COMPONENT AND CLOUD COVER. WED/WED NIGHT...A +100KT H25 JET MAX PUSHING ACROSS MEXICO WILL COMBINE WITH AN H50 VORT AXIS AHEAD OF IT TO SPIN UP A WEAK LOW PRESSURE SYSTEM ALONG A THETA-E BOUNDARY OVER THE GOMEX BY DAYBREAK WED. THE LOW WILL FORM IN A STRONG CONFLUENT FLOW GENERATED BY A LOW/MID LVL TROF PUSHING ACROSS THE NATION`S MIDSECTION...AND A DLM RIDGE OVER THE BAHAMAS/FL STRAITS. THE PREVAILING WRLY FLOW WILL PUSH THE STORM SYSTEM QUICKLY ACROSS FL ON WED...THEN INTO THE WRN ATLC WED BY NIGHT. DLM MOISTURE OVER THE GOMEX IS PLENTIFUL WITH BOTH H100-H70 AND H85-H50 MEAN RH VALUES AS HIGH AS 70%. FURTHERMORE...WITH RESPECTABLE MID/UPR LVL SUPPORT FROM THE AFOREMENTIONED H25 JET AND H50 VORT AXIS...PRECIP CHANCES ON WED WILL BE HIGH. WOULD LIKE TO SEE MORE MOISTURE POOLING WITHIN THE LOW BEFORE COMMITTING TO CATEGORICAL POPS...AND THE GFS IS SHOWING ITS POCKETS OF EXTREME 3HR PRECIP AMOUNTS THAT ARE ONE OF THE PRIMARY FLAGS FOR CONVECTIVE FEEDBACK. STILL...THE BASIC ELEMENTS ARE IN PLAY FOR A MUCH NEEDED RAIN EVENT FOR CENTRAL FL ON WED. WILL GO WITH 70% AREAWIDE FOR NOW...BUT THESE MAY BE ADJUSTED UPWARD WITH SUBSEQUENT MODEL RUNS. WARM AIR ADVECTION FROM THE DLM SWRLY FLOW WILL OFFSET THE LACK OF SUNSHINE FROM HIGH CLOUD COVER...MAX TEMPS IN THE M70S/L80S WILL BE AT OR SLIGHTLY ABV CLIMO. RAIN WILL END FROM THE NW WED NIGHT AS THE LOW TRACKS UP THE ERN SEABOARD AND H100-H85 WINDS TO VEER TO THE NW...PUSHING COOLER AND DRIER AIR INTO THE CENTRAL PENINSULA. WILL KEEP SMALL POPS IN FOR AREAS S OF THE I-4 CORRIDOR DUE TO LINGERING CLOUD COVER...MIN TEMPS ALSO A FEW DEGS ABV CLIMO (U50S/M60S). PRECIP SHOULD END AROUND MIDNIGHT ALONG AND N OF I-4 WITH READINGS WILL BE NEAR CLIMO (M50S). THU/THU NIGHT...NW FLOW WILL PREVAIL ACROSS THE CENTRAL PENINSULA AS A DLM HIGH PRES RIDGE PUSHES INTO THE SRN PLAINS/LWR MS VALLEY. COOL/DRY AIR ADVECTION WILL PREVAIL AREAWIDE...ENDING THE NEED FOR ANY MENTIONABLE PRECIP OUTSIDE OF THE GULF STREAM. THE NW WINDS WILL DROP MAX TEMPS BACK TO NEAR CLIMO (L/M70S)...WHILE CLEARING SKIES THU NIGHT WILL ALLOW MIN TEMPS TO DROP ~10-12F DEG FROM THE WED NIGHT MINS (M40S/L50S). FRI-MON...THE HIGH PRESSURE RIDGE WILL PUSH ACROSS THE DEEP SOUTH THRU THE UPCOMING WEEKEND...THEN INTO THE SW ATLC BY EARLY NEXT WEEK. N/NW WINDS WILL KEEP TEMPS NOTICEABLY COOLER FRI/SAT WITH MAX READINGS IN THE M60S/L70S...MIN TEMPS IN THE L/M40S FRI NIGHT AND M/U40S SAT NIGHT. WINDS WILL VEER TO THE E/NE BY EARLY NEXT WEEK...ALLOWING OCEAN MODIFIED AIR TO BRING TEMPS BACK TO NEAR CLIMO LVLS. && .AVIATION...AREAS MVFR CIGS/VSBYS FROM LOW STRATUS AND BR THROUGH 14Z...WITH A FEW POCKETS OF IFR/LIFR ESP 10-13Z. EXPECT SOME MVFR CIGS TO PERSIST TODAY WITH SCT SHRA DEVELOPING THIS AFTERNOON THROUGH TONIGHT AND ISOLD TSRA PSBL...ESP NEAR AND S OF OLD FRONTAL BOUNDARY DRIFTING BACK N FROM S FL THROUGH TONIGHT. && .MARINE...WINDS GENERALLY AOB 10KT AND VEERING FROM N-NE TO E-SE NEXT 24 HOURS AS OLD FRONTAL BOUNDARY DRIFTS BACK NORTHWARD FROM S FL. A FEW TSRA PSBL THIS AFTN THROUGH TONIGHT. WED-SAT...POOR BOATING CONDITIONS ANTICIPATED WED/WED NIGHT AS A STORM SYSTEM PULLS ACROSS THE FL PENINSULA THEN UP THE ERN SEABOARD. WINDS WILL SHIFT RAPIDLY FROM THE S/SE TO THE N/NW WED AFTN AND EVNG AS THE CENTER OF THE LOW MOVES INTO THE OPEN ATLC. A MODERATE TO FRESH NWRLY FLOW WILL LINGER BEHIND THE LOW ON THU AND FRI AS THE TRAILING RIDGE BEHIND THE LOW PUSHES ACROSS THE DEEP S. LIMITED FETCH LENGTH NEARSHORE SHOULD KEEP SEAS AOB 6FT...BUT A NRLY SWELL OVER THE OFFSHORE WATERS SHOULD KEEP SEAS ELEVATED NEAR OR AT SCA LVLS OFFSHORE. && .PRELIMINARY POINT TEMPS/POPS... DAB 76 67 75 63 / 40 50 70 20 MCO 79 66 79 65 / 40 50 70 20 MLB 80 69 80 67 / 40 50 70 30 VRB 81 70 80 66 / 40 50 70 30 LEE 77 65 77 62 / 40 50 70 20 SFB 78 66 78 64 / 40 50 70 20 ORL 79 66 79 66 / 40 50 70 20 FPR 81 71 80 66 / 40 50 70 30 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ SHORT TERM/AVIATION...GLITTO LONG TERM....BRAGAW