AFDMFL AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 1239 AM EST SUN FEB 5 2012 .AVIATION...THRU 06Z MON. PLENTY OF CLOUD COVERAGE WITH ISOLATED TO SCATTERED SHOWERS DEVELOPING AND SPREADING NORTHWEST OVER SOUTH FLORIDA CONTINUES TO BE SUPPORTED IN THE LATEST MODEL GUIDANCE THROUGH THE EXTENT OF THIS FORECAST CYCLE. SUB VFR CONDITIONS FOR BRIEF PERIODS WILL CERTAINLY REMAIN A POSSIBILITY DUE TO REDUCED CIGS/VSBYS IN AND AROUND THESE DEVELOPING SHOWERS. THE LOW-LEVEL FLOW WILL REMAIN OUT OF THE SOUTHEAST AS A WEAK AREA OF LOW PRESSURE EVOLVES ACROSS THE SOUTH- CENTRAL GULF OF MEXICO TODAY. 85/AG && .PREV DISCUSSION... /ISSUED 836 PM EST SAT FEB 4 2012/ UPDATE... NO CHANGES TO THE EXISTING FORECAST AT THIS TIME ... SHOWERS CONTINUE TO AFFECT THE COASTAL WATERS OF THE EAST COAST, MAINLY SECTIONS OF BROWARD AND PALM BEACH COUNTIES THIS EVENING. ISOLATED TO SCATTERED SHOWERS WILL CONTINUE TONIGHT DUE TO THE MODERATE EASTERLY FLOW AND SUFFICIENT MOISTURE DEPTH. WARM TEMPERATURES CAN BE EXPECTED AGAIN TONIGHT WITH LOWS IN THE 60S TO AROUND 70. THE RUC RAPID REFRESH MODEL FOR TONIGHT GENERATES CONVECTIVE ACTIVITY OVER THE GULF OF MEXICO OUTSIDE OF THE GULF COASTAL WATERS. HOWEVER, IT HINTS AT INCREASED SHOWER ACTIVITY TOWARD THE EARLY MORNING HOURS OVER MIAMI-DADE AND BROWARD. THE SPC MESOSCALE ANALYSIS SHOWS MOISTURE CONVERGENCE AND AN INCREASE IN THETA AND MIXING RATION BETWEEN BROWARD AND PALM BEACH COUNTIES FOR THE PAST HOUR, WHICH COINCIDES WITH THE AREA OF SHOWER ACTIVITY OBSERVED AT THE PRESENT TIME. THE FORECAST REASONING REMAINS UNCHANGED. AN UPPER LEVEL TROUGH THAT EXTENDS FROM THE YUCATAN INTO THE CENTRAL/EASTERN GULF WILL MOVE TOWARDS SOUTH FLORIDA/FLORIDA STRAITS ON SUNDAY INTO MONDAY...WITH PWATS SLOWLY INCREASING THROUGH THIS TIME. THE PRECIP AMOUNTS ARE STILL EXPECTED TO BE ON THE LIGHT TO MODERATE SIDE...WITH RAINFALL TOTALS OF 1/4 TO 1/2 AN INCH FOR THE NAPLES AND WEST OF LAKE OKEECHOBEE...AND 1/2 TO 1.5 INCHES FOR THE EAST COAST METRO REGIONS. PREV DISCUSSION... /ISSUED 704 PM EST SAT FEB 4 2012/ AVIATION...LITTLE CHANGE IN THE EXPECTED CONDITIONS OVER THE NEXT 12 HOURS WITH CONTINUED EASTERLY FLOW AND ISOLATED TO SCATTERED SHOWER ACTIVITY. CEILINGS WILL BECOME A BIT LOWER OVERNIGHT WITH BRIEF MVFR CONDITIONS POSSIBLE, EXCEPT AT KPBI, WHERE THEY WILL BE MORE PREVALENT. WINDS WILL BECOME SOUTHEAST AT 10-13 KNOTS BY SUNDAY MORNING WITH SHOWER ACTIVITY SLOWLY BECOMING MORE NUMEROUS THROUGHOUT THE DAY. A FEW TSRA COULD FORM BY SUNDAY AFTERNOON, BUT WILL ONLY MENTION VCSH AT THIS TIME. PREV DISCUSSION... /ISSUED 303 PM EST SAT FEB 4 2012/ DISCUSSION... SURFACE HIGH PRESSURE IS MOVING EAST INTO THE ATLANTIC AS LOW PRESSURE MOVES INTO THE TENNESSEE VALLEY. THIS WILL ALLOW THE PRESSURE GRADIENT TO SLOWLY RELAX TONIGHT AND SUNDAY...WITH WINDS VEERING TO THE SOUTHEAST. ISOLATED TO SCATTERED SHOWERS WILL CONTINUE TONIGHT DUE TO THE MODERATE EASTERLY FLOW AND SUFFICIENT MOISTURE DEPTH. WARM TEMPERATURES CAN BE EXPECTED AGAIN TONIGHT WITH LOWS IN THE 60S TO AROUND 70. MOSTLY CLOUDY SKIES CAN BE EXPECTED TONIGHT THROUGH THE BEGINNING OF NEXT WEEK DUE TO UPPER LEVEL CLOUDINESS FROM A LOW LEVEL TROUGH THAT EXTENDS FROM THE YUCATAN INTO THE CENTRAL/EASTERN GULF. THIS FEATURE WILL MOVE TOWARDS SOUTH FLORIDA/FLORIDA STRAITS ON SUNDAY INTO MONDAY...WITH PWATS SLOWLY INCREASING THROUGH THIS TIME. MODEL SOLUTIONS DIFFER ON HOW FAST AND HOW FAR NORTH THE LOW/MID LEVEL MOISTURE WILL MOVE INTO THE REGION. THE GFS HAS THE MOISTURE FURTHER NORTH THAN THE ECMWF ON THE 12Z RUNS...BRINGING THE MOISTURE IN MOST OF THE REGION LATE SUNDAY AFTERNOON THROUGH MONDAY MORNING. THE ECMWF ONLY BRINGS IN THE DEEPEST MOISTURE TO THE SOUTHERN PORTION OF THE REGION. THIS DIFFERS FROM THE 00Z RUN...AND THE 00Z SOLUTION WAS MORE SIMILAR TO THE GFS. HOWEVER...IT APPEARS THAT MUCH NEEDED RAINFALL WILL BE MOVING INTO THE REGION LATE SUNDAY THROUGH MONDAY. THE RIGHT ENTRANCE REGION OF A WEAK UPPER JET WILL BE OVER THE REGION SUNDAY AFTERNOON INTO THE SUNDAY EVENING AND THIS WILL ENHANCE LIFT AT THE SAME TIME MOISTURE IS INCREASING OVER THE REGION. SO KEPT CHANCE POPS SUNDAY FOR MOST OF SOUTH FLORIDA. BUMPED UP POPS TO HIGH END CHANCE TO LIKELY FOR THE SOUTHERN AND SOUTHEAST PORTIONS OF THE CWA FOR SUNDAY NIGHT. ALSO KEPT MENTION OF THUNDER FOR THE SOUTHERN HALF OF THE REGION FOR SUNDAY AFTERNOON AND SUNDAY NIGHT. THE DEEPER MOISTURE MAY BE MOVING OUT OF THE REGION MONDAY MORNING...BUT A WEAK FRONTAL BOUNDARY IS EXPECTED TO MOVE TOWARDS SOUTH FLORIDA. THE LOW LEVEL TROUGH MAY ALSO STAY OVER THE REGION THROUGH MONDAY AFTERNOON. SO BUMPED UP POPS TO CHANCE TO LIKELY ACROSS THE REGION ON MONDAY. ATTM...IT APPEARS THE PRECIP AMOUNTS MAY BE ON THE LIGHT TO MODERATE SIDE...WITH RAINFALL TOTALS OF 1/4 TO 1/2 AN INCH FOR THE NAPLES AND WEST OF LAKE OKEECHOBEE...AND 1/2 TO 1.5 INCHES FOR THE EAST COAST METRO REGIONS. WENT BELOW GUIDANCE FOR HIGH TEMPERATURES ON MONDAY BY A COUPLE DEGREES DUE TO EXPECTED CLOUD COVER AND RAINFALL. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 79 67 77 67 / 30 50 50 20 FORT LAUDERDALE 79 67 79 69 / 40 60 60 20 MIAMI 80 67 79 69 / 40 60 60 20 NAPLES 80 65 79 64 / 30 30 30 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$