000
FXUS62 KMLB 031952
AFDMLB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
252 PM EST WED DEC 3 2008
.DISCUSSION...
TONIGHT/THU...ONSHORE FLOW WILL CONTINUE TO MODIFY THE COOL DRY
AIRMASS. AS A RESULT...LOW TEMPS WILL NOT BE AS COLD...RANGING
FROM THE LOW 40S ACROSS THE FAR NORTH TO THE UPPER 50S ALG THE
TREASURE COAST. MARINE STRATOCU COULD KEEP MIN TEMPS HIGHER THAN
GFS MOS FORECASTS ALG THE COAST SOUTH OF THE CAPE. HIGHS THU
SHOULD REACH LOW-MID 70S JUST ABOUT EVERYWHERE BUT QUITE A BIT OF
STRATOCU WILL BE PRESENT. WILL CALL IT PARTLY CLOUDY BUT COULD
SEE PERIODS OF CONSIDERABLE CLOUDINESS. THINK THE AIRMASS WILL
REMAIN TOO DRY FOR ANY COASTAL SHOWERS.
THU NIGHT-FRI NIGHT...PROGRESSIVE PATTERN OVERNIGHT THURSDAY GIVES
WAY TO SHARPENING TROUGH OVER THE MISSISSIPPI RIVER VALLEY AND
SOUTHEAST AS STRONG UPPER JET OVER THE CANADIAN PLAINS DIGS TOWARD
THE GULF OF MEXICO AND FLORIDA. SURFACE HIGH PRESSURE CENTERED
EAST OF VA/NC CONTINUES TO SHIFT EASTWARD AS TROUGH OF LOW
PRESSURE/COLD FRONT SWEEPS ACROSS THE SOUTHEAST AND GULF. THE
FRONT DOES NOT APPEAR TO HAVE MUCH PRECIP POTENTIAL WITH IT AS THE
MOISTURE RIBBON ASSOCIATED WITH IT THINS CONSIDERABLY AS THE FRONT
WORKS ITS WAY ACROSS THE SOUTHEAST AND DOWN THE FLORIDA PENINSULA.
MODEL TIME HEIGHT CROSS SECTIONS FROM THE MID POINT OF AL/GA
BORDER TO LAKE OKEECHOBEE SHOWED A RELATIVELY SHALLOW LAYER OF
MOISTURE (TO 850MB) AND ANOTHER LAYER OF MOISTURE ABOVE 500MB
SUGGESTING MID/HIGH CLOUDINESS FRIDAY NIGHT AND SATURDAY AHEAD OF
ANOTHER BOUNDARY MOVING ACROSS THE LOWER MISSISSIPPI RIVER VALLEY
SAT NIGHT-SUN. KEPT LESS THAN 15 POP THESE THREE PERIODS AND
TEMPERATURES HOVERING AROUND THEIR NORMAL LOW/MID 50S IN THE
MORNING AND LOW/MID 70S IN THE AFTERNOON.
SAT-WED...LONGER TERM SECTION OF THE CANADIAN/ECMWF/GFS STILL
DIVERGE AFTER SUNDAY AS TO THEIR TUESDAY FORECAST WITH ECMWF
PLACING A FRONT OVER THE FLORIDA BIG BEND AREA AND THE MUCH
SLOWER CANADIAN PUTTING THE FRONT OVER THE EASTERN HALF OF TEXAS.
MIDSHIFT EXTENDED DISCUSSION PROVIDED BELOW...
WEEKEND...A MORE SIGNIFICANT SHORTWAVE TROUGH DROPPING SOUTHEAST
OUT OF CANADA WILL AMPLIFY THE FLOW PATTERN ALOFT AND THE
ASSOCIATED REINFORCING COLD FRONT IS FORECAST TO PASS THROUGH THE
AREA SAT NIGHT. USUALLY THESE TYPES OF FRONTAL PASSAGES DO NOT
PRODUCE MUCH RAIN AND MOS POPS ARE AROUND 15 PERCENT SAT
NIGHT...SO WILL KEEP THE FORECAST DRY.
SAT LOOKS LIKE ANOTHER MILD DAY...SIMILAR TO FRI...AS WEAKENING
FRONTAL BOUNDARY WAITS FOR REINFORCEMENT FROM THE NORTHWEST.
SUNDAY SHOULD BE A COOLER THAN NORMAL DAY WITH MAX TEMPS FROM THE
MID 60S NORTH TO LOWER 70S FAR SOUTH.
MON-WED...A LARGE HIGH PRESSURE SYSTEM WITH CENTER WELL TO OUR
NORTH IS FORECAST TO SHIFT TO THE EASTERN SEABOARD LATE MON AND
OFFSHORE TUE. THIS WOULD ALLOW FOR AIR MASS MODERATION AND TEMPS
GETTING BACK TO AROUND NORMAL TUE. THE LATEST GFS PUSHES A COLD
FRONT THROUGH THE AREA TUE NIGHT...BUT THE ASSOCIATED SHORTWAVE
SHOULD BE TO OUR NORTH SO THE CHANCE FOR SHOWERS LOOKS LOW. THE
ECMWF CONTINUES TO BE 12 HOURS OR MORE SLOWER...SO WILL NOT
INTRODUCE POPS TUE OR THE NEW DAY 7 (WED). WILL LET DAY SHIFT LOOK
AT MODEL TREND FOR TUE NIGHT/WED AND SEE IF A SMALL POP IS
WARRANTED. COLD ADVECTION SHOULD NOT BE VERY STRONG WITH TEMPS
COOLING A LITTLE BELOW NORMAL WED.
&&
.AVIATION...VFR. MARINE STRATOCU WILL PRODUCE OCNL CIGS FL040-050
MNLY ALG THE COAST.
&&
.MARINE...HIGH PRESSURE WILL PUSH NE OFF THE CAROLINA COAST
TONIGHT AND THU. PRES GRAD WILL REMAIN A BIT TIGHTER ACROSS
SOUTHERN WATERS TONIGHT (12-15 KTS) BUT LOOSEN THU AS TRAILING
RIDGE AXIS SLIPS SOUTHWARD ACROSS THE WATERS. PRES GRAD WILL
SUPPORT ONLY 5-10 KTS THU WITH LITTLE WIND WAVE (~1 FT). PRIMARY
CONTRIBUTION TO SEA HGT WILL BE A 2 FT LONG PERIOD EAST SWELL.
LOOKS LIKE A GOOD BOATING DAY.
THU NIGHT-MON...LIGHT EAST SOUTHEAST FLOW THU NIGHT BECOMES
VARIABLE FRI AS HIGH PRESSURE PULLS AWAY INTO THE ATLANTIC AND A
WEAKENING FRONTAL BOUNDARY MOVES DOWN THE PENINSULA FRI-SAT.
WESTERLY FLOW RIGHT BEHIND THE FRONT BECOMES NORTHWEST THEN NORTH
SUN AND SUN NIGHT AS HIGH PRESSURE INITIALLY BUILDS ACROSS THE
SOUTHEAST AND FLORIDA. SEAS SHOULD BUILD MORE IN THE GULF STREAM
WITH THE NORTHERLY FLOW SUN. WINDS SHIFT TO THE NORTHEAST BY MON
AS HIGH PRESSURE CENTERED OVER THE OHIO RIVER VALLEY MOVES TO THE
OUTER BANKS AREA OF NORTH CAROLINA.
&&
.FIRE WEATHER...NO WIND OR LOW RH CONCERNS THRU THU. WIDESPREAD
FOG FORMATION IS NOT EXPECTED TONIGHT. HOWEVER...NEARLY FULL
RECOVERY OF RH IS EXPECTED. LIMITED MOISTURE TRAPPED BENEATH
SURFACE BASED INVERSION COULD PRODUCE PATCHY DENSE FOG IN VICINITY
OF ANY SMOLDERING FIRES. VERY LIGHT WIND PROFILES AND INCREASED
LOW LEVEL MOISTURE WILL PROMOTE A BETTER CHANCE OF PATCHY DENSE
FOG OVER THE INTERIOR WED NIGHT/THU MORNING.
FRI-SUN...MIN RH VALUES ARE FORECAST TO BE ABOVE 40 PERCENT
THROUGH THE PERIOD...HOWEVER WILL HAVE TO WATCH MIN RH VALUES
BEHIND NEXT FRONT ON SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 47 72 49 72 / 0 10 10 10
MCO 48 74 50 76 / 0 0 10 10
MLB 51 74 55 75 / 0 10 10 10
VRB 55 75 53 77 / 0 10 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...KELLY
LONG TERM....WIMMER
