000
FXUS61 KBOX 230844
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
444 AM EDT SAT MAY 23 2009
.SYNOPSIS...
A COLD FRONT JUST TO THE SOUTH OF NEW ENGLAND THIS MORNING WILL
GRADUALLY RETURN NORTH AS A WARM FRONT TODAY. A STRONGER COLD FRONT
EDGES ACROSS SOUTHERN NEW ENGLAND SUNDAY. HIGH PRESSURE SHOULD NUDGE
SOUTH FROM CANADA LATE SUNDAY...AND LINGER THROUGH TUESDAY. A COMPLEX
FRONTAL SYSTEM SHOULD IMPACT OUR REGION FOR THE SECOND HALF OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT SETTLING JUST TO THE SOUTH OF NEW ENGLAND THIS MORNING
WILL ATTEMPT TO GRADUALLY RETURN NORTH AS A WARM FRONT LATER TODAY.
HOWEVER...WITH SFC HIGH PRESSURE NOSING DOWN FROM THE NORTHEAST...MUCH
COOLER TEMPERATURES ARE IN STORE TODAY...WITH ONSHORE FLOW PREVAILING
FOR MUCH OF THE DAY. COOLEST TEMPS WILL BE FOUND ALONG THE EAST COAST
OF MASS WHERE TEMPERATURES LIKELY WON/T RISE ABOVE THE MID 60S.
WARMEST TEMPS LIKELY TO BE FOUND IN CT VALLEY.
DESPITE THE PRESENCE OF THE WEAK WARM FRONT...THERE DOESN/T SEEM TO
BE MUCH OF A MECHANISM FOR ASCENT...THEREFORE...ONLY HAVE LOW CHANCE
OR SLIGHT CHANCE POPS FOR TODAY ALONG WITH VARIABLE CLOUDINESS. BEST
CHANCE OF A SCT SHOWER MAY BE EARLY ON THIS MORNING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
MAINLY DRY NIGHT EXPECTED TODAY ALTHOUGH CANNOT RULE OUT A COUPLE OF
SHOWERS AND PERHAPS AND ISOLD TSTM AS WARM FRONT FINALLY PUSHES NORTH
AND PRETTY MUCH WASHES OUT.
A SHORT WAVE APPROACHING FROM THE NORTHWEST LATE TONIGHT AND SUNDAY
WILL AID IN PUSHING ANOTHER COLD FRONT INTO SOUTHERN NEW ENGLAND
DURING THE DAY ON SUNDAY. MODEL GUIDANCE MEMBERS ARE IN GENERAL
AGREEMENT THAT AT LEAST CHANCE POPS ARE WARRANTED SUNDAY AFTERNOON.
WE HAVE A CHANCE OF THUNDERSTORMS GOING AS WELL AS IT LOOKS LIKE
WE/LL BE ABLE TO WEAKLY DESTABILIZE. THE DEGREE OF INSTABILITY WILL
DEPEND ON BOUNDARY LAYER DEW POINT ADVECTION AS WELL AS THE AMOUNT OF
SUNSHINE. WENT WITH PARTIAL SUNSHINE AT THIS TIME WHICH SHOULD ALLOW
MAXES TO GET WELL UP INTO THE 70S. WEAK DESTABILIZATION AND 35 TO 40
KT DEEP LAYER SHEAR VALUES MAY BE ENOUGH TO ALLOW FOR A STRONG STORM
OR TWO WITH ATTENDANT THREAT FOR HAIL/WIND.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
DECENT AGREEMENT AMONGST THE MEMBERS OF THE 23/00Z OPERATIONAL MODEL
SUITE...PARTICULARLY THE GFS AND ECMWF. CONFIDENCE IN THE DETAILS
DROPS OFF THURSDAY INTO FRIDAY AS GEFS MEAN SOLUTION IS QUITE
DIFFERENT FROM THE 00Z OPERATIONAL CONSENSUS SOLUTION. GIVEN THE GOOD
AGREEMENT OF THE GFS AND ECMWF...USED THE GFS AND ITS MOS TO TWEAK
PREVIOUS FORECAST THROUGH WEDNESDAY. ALSO TWEAKED FORECAST FOR
THURSDAY AND FRIDAY...BUT NOT NEARLY AS MUCH AS THE EARLIER PORTION.
A COLD FRONT SWEEPS ACROSS SOUTHERN NEW ENGLAND SUNDAY NIGHT...
FOLLOWED BY A HIGH PRESSURE NUDGING SOUTH FROM EASTERN CANADA MONDAY.
ALTHOUGH A GENERAL NORTH TO NORTHWEST FLOW IS EXPECTED FOR MEMORIAL
DAY...THE PRESSURE GRADIENT LOOKS WEAK ENOUGH TO SUPPORT AN AFTERNOON
SEA BREEZE ALONG THE EAST COAST OF MA. THIS WOULD KEEP AFTERNOON
TEMPS ALONG THE COAST BUFFERED COMPARED TO THE INTERIOR.
THE HIGH CRESTS OVER US TUESDAY MORNING,,,THEN MOVES OFF TO THE EAST
IN THE AFTERNOON. THIS MAKES ROOM FOR INCREASING HIGH CLOUDS...
ESPECIALLY IN THE AFTERNOON...AND AN INCREASING SOUTHEAST TO SOUTH
FLOW. THIS WOULD MAKE TUESDAY A COOLER DAY THAN MONDAY. IF THE FLOW
IN THE WESTERN ZONES WERE EVEN 30 DEGREES MORE WESTERLY WE WOULD BE
EXPECTING MAX TEMPS IN THE 70S...BUT WITH A MORE MARINE FLOW WE WILL
TOP OUT THAT AREA AROUND 70 WITH COOLER TEMPS FARTHER EAST.
MODELS AGREE ON MOVING A SURFACE LOW OUT OF THE PLAINS EARLY IN THE
WEEK WITH A LITTLE DIFFERENCE IN THE ACTUAL TRACK. BUT ALL BRING GOOD
ISENTROPIC LIFT TO SOUTHERN NEW ENGLAND AFTER 06Z WEDNESDAY. THIS LIFT
AND LOW LEVEL SATURATED AIR LINGERS THROUGH WEDNESDAY. THIS LOW
SHOULD MOVE OFF TO THE EAST THURSDAY...BUT WITH THE RIGHT ENTRANCE
REGION OF THE UPPER JET LINGERING OVER US THROUGH THE DAY. SO WE
HAVE KEPT CHANCE POPS IN PLACE THROUGH MOST OF THURSDAY. DRYING FROM
NORTHWEST TO SOUTHEAST THURSDAY NIGHT INTO FRIDAY.
THE FRIDAY FORECAST IS LOW CONFIDENCE. BOTH THE GFS AND ECMWF HAVE A
WEAK SURFACE TROUGH IN OUR VICINITY...MAINLY ALONG THE SOUTH COAST.
ANOTHER COLD FRONT COULD BE MOVING SOUTH FROM THE NEW YORK/QUEBEC
BORDER. SO WHILE WE HAVE GONE WITH A DRY FORECAST FOR NOW...THIS
COULD EASILY CHANGE OVER THE NEXT FEW DAYS.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
TODAY...VFR PREVAILS.
TONIGHT...MAINLY VFR...ALTHOUGH WILL HAVE TO BE ON THE LOOKOUT FOR
DEVELOPING PATCHY LOW STRATUS/FOG IN MOISTENING LOW LEVEL AIRMASS.
MOST SUSCEPTIBLE AREA FOR SOME IFR CONDITIONS WILL BE THE SOUTH
COAST/CAPE/ISLANDS...PERHAPS AS FAR NORTH AS LOGAN LATE.
SUNDAY...MAINLY VFR WITH PATCHY LOWER CONDITIONS EARLY ON. COLD FRONT
MOVES INTO THE REGION IN THE AFTERNOON WITH ATTENDANT CHANCE OF
SHOWERS/TSTMS.
OUTLOOK /SUNDAY NIGHT THROUGH WEDNESDAY/...
SUNDAY NIGHT...MAINLY VFR...WITH SCATTERED MVFR IN SHOWERS AT NIGHT.
MONDAY AND TUESDAY...VFR.
TUESDAY NIGHT AND WEDNESDAY...CONDITIONS LOWERING TO MVFR/IFR IN
CLOUDS/SHOWERS. INCREASING EAST WINDS.
&&
.MARINE...
WEAK PRESSURE PATTERN IN PLACE SHOULD ALLOW FOR SUB-SCA CONDITIONS
TODAY THROUGH SUNDAY. WINDS START OFF EAST TODAY...THEN GRADUALLY
SHIFT TO THE SOUTH TONIGHT THEN SOUTHWEST SUNDAY. AREAS OF MARINE FOG
MAY DEVELOP TONIGHT AND LINGER INTO SUNDAY. CHANCE THUNDER SUNDAY
AFTERNOON.
OUTLOOK /SUNDAY NIGHT THROUGH WEDNESDAY/...
MONDAY AND TUESDAY...GENERALLY LIGHT SEAS AND WINDS.
WEDNESDAY...INCREASING SOUTHEAST WINDS AHEAD OF THE NEXT WEATHER
SYSTEM MAY BRING 25 KNOT GUSTS AND 5 FOOT SEAS TO THE SOUTHERN
WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...EKSTER/BELK
NEAR TERM...EKSTER
SHORT TERM...EKSTER
LONG TERM...BELK
AVIATION...EKSTER/BELK
MARINE...EKSTER/BELK
