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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCAR 181724
AFDCAR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
124 PM EDT SAT MAY 18 2013

.SYNOPSIS...
COOL HIGH PRESSURE WILL REMAIN OVER THE AREA THROUGH THE WEEKEND.
A WARM FRONT WILL MOVE INTO THE AREA LATE SUNDAY NIGHT INTO MONDAY AS
A SMALL WAVE OF LOW PRESSURE SLIDES IN FROM CANADA.&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
UPDATE 1320 EDT: HAVE ADJUSTED TEMPERATURE...POPS...SKY COVER TO
BETTER FIT OBSERVED CONDITIONS.

THE BIGGEST CONCERN IN THE NEAR TERM WILL BE THE POTENTIAL FOR A
FROST/FREEZE TONIGHT.

ALOFT...AN UPPER LOW ACROSS NORTHERN NOVA SCOTIA EARLY THIS MORNING
WILL CONTINUE EAST INTO THE NORTH ATLANTIC JUST PASSING JUST SOUTH
OF NEWFOUNDLAND TONIGHT. UPSTREAM OF THE AREA A TROUGH WILL DIG INTO
THE ROCKIES AS AN UPPER RIDGE BUILDS ACROSS THE GREAT LAKES.

AT THE SFC...A 1032 MB HIGH CENTERED OVER NEWFOUNDLAND EARLY THIS
MORNING WITH RIDGING EXTENDING SOUTH INTO MAINE.  THE HIGH WILL
DRIFT SOUTH AND INTO EASTERN NEW BRUNSWICK AND NOVA SCOTIA TONIGHT.

A COOL NORTHWEST FLOW ALOFT CONTINUES TODAY WITH WEAKLY CYCLONIC
FLOW. THERE SHOULD BE ENOUGH MOISTURE AND INSTABILITY FOR A DECENT
CU FIELD TO POP DUE TO STRONG MID MAY SFC HEATING. HIGH TEMPS ARE
EXPECTED TO BE IN THE 50S IN MOST AREAS. THE SKY SHOULD BECOME
CLEAR THIS EVENING ACROSS THE NORTHERN ZONES WITH THE LOSS OF
DAYTIME HEATING. SOME CLOUDS ARE EXPECTED TO REMAIN ACROSS THE
SOUTHWEST ZONES WHERE THE MODELS KEEP A MOIST LAYER FROM 850-700
MILLIBARS MUCH OF THE NIGHT ALONG WITH SOME CHANNELED VORTICITY.
THE GFS CONTINUES TO LOOK OVERDONE IN GENERATING SHOWERS ACROSS
THE SW ZONES THIS AFTERNOON/EVENING. LOWS ARE EXPECTED TO DROP
BELOW FREEZING IN MOST AREAS ACROSS THE NORTH WITH FROST EXPECTED
AS FAR SOUTH AS CENTRAL WASHINGTON COUNTY. WILL ISSUE A FREEZE
WARNING FOR THE NORTHERN ZONES AND FROST ADVISORIES FOR MUCH OF
THE CENTRAL AND SOUTHEAST ZONES.
-- End Changed Discussion --

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
COOL HIGH PRESSURE OVER THE AREA SUNDAY WILL BRING A MOSTLY SUNNY
AND DRY DAY. A FEW LIGHT CUMULUS WILL LIKELY DEVELOPING DURING THE
MIDDLE OF THE DAY. HIGH CLOUDS WILL BEGIN STREAMING INTO WESTERN
AREAS AS A BIT OF MOISTURE BEGINS TO ADVECT INTO THE AREA BEHIND
THE HIGH. MEANWHILE LOW PRESSURE IN THE NATIONS MID SECTION WILL
BE PULLING WARM AND HUMID AIR NORTH INTO THE GREAT LAKES REGION AS
A SMALL SHORTWAVE AND ASSOCIATED COLD FRONT PRESS SOUTH THROUGH
ONTARIO. A SURGE OF WARM ADVECTION AHEAD OF THE COLD FRONT WILL
MOVE INTO QUEBEC SUNDAY EVENING THEN SLIDE SOUTHEAST INTO OUR AREA
EARLY MONDAY MORNING BRINGING AN AREA OF RAIN. THE NAM HAS MOST OF
THE RAIN FALLING IN CENTRAL AND SOUTHERN AREAS WHILE THE GFS
CARRIES MOST OF THE RAIN TO OUR NORTH. THE TRACK OF THE WEATHER
DISTURBANCE ACROSS THE AREA AND FOCUS OF THE HEAVIEST RAINFALL
WILL LIKELY BE INFLUENCED AND COMPLICATED BY ANY CONVECTION
INCLUDING ANY MCC`S ALONG THE FRONTAL BOUNDARY IN THE NORTHERN
PLAINS AND GREAT LAKES AREA. THE STRENGTH OF THE WARM ADVECTION
OVER THE COOLER AIR IN PLACE WILL LIKELY PRODUCE AT LEAST SOME
RAIN OVER THE REGION. SOME SHOWERS MAY LINGER INTO LATER MONDAY
ALONG THE FRONTAL BOUNDARY ACROSS THE NORTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A FRONTAL BOUNDARY BETWEEN RELATIVELY COOLER AND DRIER AIR TO THE
NORTH AND WARMER MORE HUMID AIR TO THE SOUTH WILL BE ACROSS THE
AREA THROUGH THE MID AND LATE WEEK KEEPING THE WEATHER UNSETTLED.
THE BOUNDARY MAY PUSH SOUTH LATE TUESDAY INTO WEDNESDAY THEN LIFT
NORTH AS LOW PRESSURE MOVES ALONG THE FRONT THURSDAY INTO FRIDAY
PUSHING SHOWERS BACK NORTHWARD. THE PROXIMITY OF THE BOUNDARY
MEANS THE AIR ACROSS THE NORTH WILL LIKELY BE SIGNIFICANTLY COOLER
AND LESS HUMID THAN AIR ACROSS THE SOUTH. SHOWERS WILL BE POSSIBLE
ANY TIME THROUGH THE WEEK. TIMING INDIVIDUAL DISTURBANCES ALONG
THE BOUNDARY WILL LIKELY BE CHALLENGING IN THE LONG RANGE BUT
BECOME EASIER TO DISCERN WITHIN 24 TO 48 HOURS LEAD TIME.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
NEAR TERM: VFR EXPECTED THROUGH TONIGHT.

SHORT TERM: VFR CONDITIONS ARE LIKELY SUNDAY INTO SUNDAY EVENING.
CONDITIONS WILL LOWER TO IFR LATE SUNDAY NIGHT AND LIKELY REMAIN
IFR IN LOW CLOUDS AND RAIN ON MONDAY. CONDITIONS MAY IMPROVE TO
VFR LATE MONDAY. MVFR CONDITIONS DOWNEAST AND VFR CONDITIONS
ACROSS THE NORTH ARE LIKELY TUESDAY INTO WEDNESDAY.

&&

.MARINE...
NEAR TERM: A LIGHT WIND REGIME THROUGH TONIGHT AS A SFC HIGH BUILDS
OVER THE WATERS WITH SEAS REMAINING BELOW SCA LEVELS.

SHORT TERM: WINDS AND SEAS ARE EXPECTED TO BE BELOW SCA SUNDAY AND
MAY REACH SCA LATE MONDAY INTO MONDAY EVENING. WINDS AND SEAS
SHOULD THEN BE BELOW SCA THROUGH MID WEEK. HUMID AIR MOVING OVER
THE WATERS MAY BRING SOME FOG LATE SUNDAY NIGHT INTO MONDAY.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...FREEZE WARNING FROM 2 AM TO 7 AM EDT SUNDAY FOR MEZ001>006.
     FROST ADVISORY FROM 2 AM TO 7 AM EDT SUNDAY FOR MEZ011-017-032.
MARINE...NONE.

&&

$$

NEAR TERM...MIGNONE