Area Forecast Discussion Issued by NWS Caribou, ME
000
FXUS61 KCAR 211613
AFDCAR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
1213 PM EDT TUE MAY 21 2013
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN ALONG THE SOUTHERN PART OF OUR
REGION THROUGH MID WEEK. SMALL WAVES OF LOW PRESSURE WILL TRACK
ALONG THIS BOUNDARY TODAY AND WEDNESDAY. A LARGER STORM SYSTEM
FROM THE MIDWEST WILL TRACK TO OUR WEST ON THURSDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
NOON UPDATE: LATEST RADAR REF SHOWS A SHARP CUT-OFF OF SHWRS
DEVELOPING ACROSS N CNTRL ME...SLOWLY MOVG SE. WITH THIS IN MIND...
WE LOWERED POPS TO ISOLD FOR ERLY AFTN ACROSS THE FAR NRN ZONES 1
AND 2 AND MENTIONED THAT SHWRS WILL MSLY AFFECT THE REST OF THE FA
ERLY THIS AFTN...THINKING THAT A BACK EDGE OF SHWRS WILL CLR MOST
OF THE FA BY LATE AFTN. STILL HOLD OUT HOPE THAT PARTIAL CLRG
FROM ERN QB NOW APCHG FAR NW ME WILL AT LEAST GET INTO FAR NRN
PTNS OF THE FA BY LATE AFTN. BREAKS IN THE OVC SHOULD GET INTO
N CNTRL AND CNTRL PTNS OF THE FA BY VRY LATE THIS AFTN...BUT
ONLY ENOUGH TO MENTION MCLDY VS CLDY SKIES. DID NOT CHG HI TEMPS
ATTM...THINKING LATE DAY SUNSHINE WILL ALLOW HI TEMPS TO REACH
THESE NUMBERS...RE-TREND FCST HRLY TEMPS TO FCST HI TEMPS
FROM 11 AM OBSVD TEMPS ACROSS OUR FA...IMPLYING A SLOWER RISE
TO POSTED HI TEMPS AT 5 PM.
935 AM UPDATE: ONE MORE UPDATE TO DROP MENTION OF PATCHY FOG AND
TO INCREASE POPS A LITTLE FURTHER N AND E FOR LATE THIS MORN BASED
ON THE LATEST RADAR REF PRESENTATION. MADE CORRESPONDING CHGS WITH
12Z-18Z AND TO A LESSER XTNT 18-00Z QPF TOTALS ACROSS THE FA BASED
ON THIS CHG OF POP DISTRIBUTIONS...WITH MINIMUMS OF 0.05 INCHES
EACH PD FOR LIKELY POPS AND AT LEAST 0.15 INCHES FOR CATEGORICAL
POPS. REST OF NEAR TERM ELEMENTS UNCHGD THIS UPDATE.
810 AM UPDATE: VSBYS HAVE RISEN SIG SINCE LAST UPDATE...SO WE
DROPPED THE DENS FOG ADV AND MENTIONED PATCHY FOG TIL LATE MORN...
AFTER WHICH FOG WILL NO LONGER BE ANY ISSUE. THE OTHER MAJOR CHG
WAS TO INCREASE SHWR POPS OVR S AND W PTNS OF THE FA TO BETTER
THE FCST QPF WE SHOW FOR THE 12-18Z PD TODAY...USING THE POP
FROM QPF TOOL. THIS AWARDED CATEGORICAL POPS TO FAR S AND W
PTNS OF THE FA. RADAR CURRENTLY INDICATES RNFL CONSOLIDATING
SEWRD OVR THESE PTNS OF THE FA...WITH LITTLE MOVEMENT OF ECHOES
IN THE NW MOVG TOWARD THE NE. EVEN SO...WE HAVE SCT SHWR POPS FOR
THE NE AND FAR NW FOR THIS MORN...WHICH IS HIGHER POPS THAN WE
THOUGHT YSTDY FOR THIS PD AND PTN OF THE FA. LAST CHG WAS TO
RE-TREND FCST HRLY TEMPS TO FCST HI TEMPS FROM THE 8 AM OBSVD
TEMPS ACROSS OUR FA.
6 AM UPDATE: AREAS OF DENSE FOG CONTINUE TO COVER EASTERN AREAS.
THE DENSE FOG ADVISORY WAS EXTENDED UNTIL 8 AM AFTER WHICH THE
DAYS HEATING SHOULD BEGIN TO THIN OUT THE FOG. TODAY WILL THEN
REMAIN HUMID WITH AN AREA OF SHOWERS MOVING THROUGH CENTRAL AND
DOWNEAST LOCATIONS THROUGH MIDDAY AS A SMALL DISTURBANCE TRACKS
THROUGH THE REGION.
ORGNL DISC: HUMID AIR ACROSS THE REGION HAS ALLOWED DENSE FOG TO
FORM IN MANY AREAS. THE FOG WILL DISSIPATE IN MOST AREAS THIS
MORNING BUT WILL LIKELY PERSIST ALONG THE COAST. SKIES WILL REMAIN
MOSTLY CLOUDY TODAY WITH STRATUS TO THE SOUTH AND STRATOCUMULUS
ACROSS THE NORTH. A WEAK WEATHER DISTURBANCE TRACKING ALONG THE
BOUNDARY TO OUR SOUTH WILL BRING SHOWERS TO CENTRAL AND DOWNEAST
AREAS TODAY AND SOME LIGHT SHOWERS MAY BRUSH THE NORTH DURING THE
MID MORNING PERIOD. THIS WILL GIVE WAY TO A MOSTLY CLOUDY NIGHT
TONIGHT. A LARGER WAVE OF LOW PRESSURE WILL APPROACH LATE TONIGHT
SPREADING RAIN INTO THE AREA AFTER MIDNIGHT. MOST OF THE RAIN IS
EXPECTED ACROSS CENTRAL AREAS WITH MODELS DIFFERING ON HOW MUCH
RAIN WILL MAKE IT TO THE NORTH. THE AIR IS EXPECTED TO REMAIN
HUMID TODAY AND TONIGHT WITH FOG LIKELY IN MANY AREAS AGAIN
TONIGHT IN THE HUMID AIR.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/...
A DISTURBANCE MOVING ALONG A FRONTAL BOUNDARY IS FORECAST TO BRING
UP TO TWO THIRDS OF INCH OF QPF TO NORTHERN AND CENTRAL MAINE ON
WEDNESDAY. THE FRONTAL BOUNDARY MOVES TO THE NORTH OF MAINE
WEDNESDAY NIGHT AND ALLOWS A WARM SECTOR TO SET UP FOR THURSDAY.
MODELS DIFFER A BIT ON MUCAPE VALUES IN THE WARM SECTOR...THAT BEING
SAID VALUES IN THE 500-1000 J/KG RANGE WILL BE POSSIBLE. THIS
SHOULD ALLOW FOR SHOWERS AND THUNDERSTORMS TO DEVELOP DURING THE
DAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE 00Z GFS DIVERGES FROM PREVIOUS RUNS AND CLOSES OFF AN H5 UPPER
LOW FOR THE MEMORIAL DAY WEEKEND. THIS WOULD RESULT IN A DAMP AND
COOL HOLIDAY WEEKEND. THE 00Z CANADIAN DEVELOPS AN UNSEASONABLY
STRONG COASTAL LOW OFF THE SOUTHERN NEW ENGLAND COAST AND MOVES IT
INTO THE GULF OF MAINE ON SATURDAY. THE FRONT DOES CLEAR THE COAST
SATURDAY NIGHT AND PROVIDES A DRY SUNDAY AND MEMORIAL DAY.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: IFR CONDITIONS ARE EXPECTED THIS MORNING. CONDITIONS
WILL LIKELY REMAIN IFR DOWNEAST TODAY INTO TONIGHT IN LOW CLOUDS
AND FOG. CONDITIONS SHOULD IMPROVE TO MVFR BY MIDDAY TODAY ACROSS
THE NORTH AND THEN VFR LATE TODAY. VFR CONDITIONS OVER THE NORTH
TONIGHT MAY LOWER TO IFR IN FOG AGAIN LATE TONIGHT.
SHORT TERM: IFR/MVFR CIGS AND VSBYS ARE EXPECTED AT TAF SITES ON
WEDNESDAY IN RAIN AND FOG. MVFR CIGS AND VSBYS ARE FORECAST FOR
THURSDAY IN SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
NEAR TERM: WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA TODAY
AND TONIGHT. HUMID AIR OVER THE WATERS WILL RESULT IN FOG
PERSISTING OVER THE WATERS THROUGH TONIGHT.
SHORT TERM: SCA CONDITIONS ARE EXPECTED WEDNESDAY NIGHT AND THURSDAY
WITH WAVE HEIGHTS 6 TO 10 FEET AND WIND GUSTS TO 30 KNOTS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...VJN
SHORT TERM...OKULSKI
LONG TERM...OKULSKI
AVIATION...VJN/OKULSKI
MARINE...VJN/OKULSKI