Area Forecast Discussion
Issued by NWS Portland, ME

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000
FXUS61 KGYX 161629
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1229 PM EDT THU OCT 16 2014

.SYNOPSIS...
A COLD FRONT WILL SLOWLY APPROACH FROM THE WEST TODAY AND WILL
FINALLY CROSS THE REGION LATE TONIGHT. A WEAK RIDGE OF HIGH
PRESSURE WILL BUILD IN BEHIND THE FRONT ON FRIDAY. A SECONDARY
COLD FRONT WILL APPROACH FROM THE WEST FRIDAY NIGHT AND SATURDAY
AND WILL CROSS THE REGION SATURDAY NIGHT. HIGH PRESSURE WILL
GRADUALLY BUILD IN FROM THE WEST SUNDAY THROUGH MONDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1230 PM UPDATE...HAVE ISSUED A FLASH FLOOD WATCH FOR AREAS OF NH
AND ME THAT WILL LIKELY BE MOST IMPACTED BY UPSLOPE-ENHANCED
RAINFALL THIS AFTERNOON AND TONIGHT. LOCALIZED 3-4 INCH TOTALS
POSSIBLE AND COULD LEAD TO LOCALIZED FLASH FLOODING. MAY ADD THE
REST OF THE AREA LATER...BUT MAINLY EXPECTING MORE NUISANCE URBAN
FLOODING IN THOSE AREAS OUTSIDE THE WATCH AREA.

10 AM UPDATE...LITTLE CHANGE TO THE GOING FORECAST AT THIS TIME.
BANDS OF RAIN...HEAVY AT TIMES...MAINLY TO OUR WEST AND SOUTHWEST
THIS MORNING WILL GRADUALLY PUSH EASTWARD THIS AFTERNOON AND
EVENING...LIKELY RESULTING IN MINOR URBAN/POOR-DRAINAGE FLOODING.

615 AM UPDATE...UPDATED TEMPERATURES BASED ON CURRENT OBS AND
TRENDS...ARE ON THE LEE SIDE OF THE WHITES MOUNTAINS WERE ABOUT 5
DEGREES WARMER THAN ANY GUIDANCE THIS MORNING WITH FAVORABLE
DOWNSLOPE AND ADIABATIC HEATING WHITEFIELD WAS STILL IN THE LOW
70S AS OF 6AM. SHOWERS ARE ON THE INCREASE ACROSS THE AREA WITH A
LINE OF SHOWERS RUNNING FROM SOUTH TO NORTH ALONG THE VT AND NH
BORDER. THE REST OF THE CWA IS ONLY SEEING ISOLATED LIGHT
RAINSHOWERS AND DRIZZLE THIS MORNING. HEAVY RAIN WILL CONTINUE TO
PUSH NORTH AND EAST AS WE HEAD THROUGH THE MORNING HOURS WITH THE
HEAVIEST RAIN MOVING IN THIS AFTERNOON.

PREVIOUS DISCUSSION...
LOW CLOUDS WITH FOG AND DRIZZLE WILL PERSIST THIS MORNING WITH ON
SHORE FLOW. AS OF 3 AM THE HEAVIEST RAIN SHOWER WERE STILL ACROSS
EASTERN NY. THE COLD FRONT WILL START TO PUSH INTO NEW ENGLAND
THIS AFTERNOON AND SPREAD THE HEAVY RAINFALL INTO OUR AREA. UPPER
TROF GOES NEGATIVELY TILTED AND HELPS PULL IN THE MOISTURE FROM
GONZALO. MOIST AIRMASS AND STRONG ISENTROPIC LIFT WITH FAVORABLE
UPPER LEVEL DIFFLUENCE WILL SUPPORT HEAVY RAINFALL. TRAINING
POTENTIAL WILL BE FAIRLY HIGH WITH STORMS MOVING SOUTH TO NORTH
AND ENHANCED CONVECTION DUE TO ADDED LIFT FROM THE TERRAIN IS
EXPECTED. FOR THE MOST PART WE SHOULD ESCAPE FLASH
FLOODING...HOWEVER POOR DRAINAGE AREAS AND PONDING ON ROADWAYS
ALONG WITH MAYBE AN ISOLATED FLASH FLOOD EVENT IN HIGH RUNOFF
POTENTIAL AREAS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
REALLY...VERY LITTLE CHANGE TO THE FORECAST AS MODELS HAVE
REMAINED CONSISTENT OVER THE PAST FEW RUNS.  HEAVY RAIN IS
EXPECTED THURSDAY NIGHT ACROSS MUCH OF THE AREA. TROPICAL MOISTURE
WILL BE PUMPED INTO THE REGION WITH MODERATE TO STRONG SOUTHEAST
FLOW AT 850 MB. CURRENTLY LOOKING AT WIDESPREAD 1 TO 2 INCHES OF
RAINFALL WITH HIGHER AMOUNTS IN FAVORABLE UPSLOPING LOCATIONS OF
THE WHITES AND WESTERN MOUNTAINS OF MAINE. THERE WILL ALSO BE SOME
MARGINAL INSTABILITY WHICH COULD KICK OFF AN ISOLATED EMBEDDED
THUNDERSTORM. LOOK FOR THE PRECIP TO START WINDING DOWN FROM WEST
TO EAST FRIDAY MORNING WITH SOME BREAKS OF SUN BY THE AFTERNOON.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
MODELS CONTINUE TO COME INTO BETTER AGREEMENT WITH THE TIMING OF A
PASSAGE OF A STRONG COLD FRONT ACROSS MAINE AND NEW HAMPSHIRE
SATURDAY EVENING. THIS WILL BRING IN SIGNIFICANTLY COOLER AIR FOR
SUNDAY WITH HIGH TEMPERATURES ONLY REACHING THE 40S IN THE
MOUNTAINS.

THE NEXT INTERESTING FEATURE WILL BE YET ANOTHER CUTOFF LOW
PRESSURE SYSTEM DURING THE MIDWEEK PERIOD NEXT WEEK. MODELS
CONTINUE TO SUGGEST AN AREA OF LOW PRESSURE WILL DEVELOP OFF THE
NEW ENGLAND COASTLINE. MODELS DO DIVERGE WITHIN THE 00Z SUITE
HOWEVER AS TO THE STRENGTH OF THIS SYSTEM AND WHETHER IT WILL
RETROGRADE BACK TOWARDS THE NEW ENGLAND COAST. THIS WILL NEED TO
BE MONITORED IN FUTURE RUNS FOR THE POTENTIAL OF SOME COASTAL
FLOODING NEXT WEEK.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
SHORT TERM...MAINLY LIFR TO IFR CONDITIONS ACROSS THE AREA THROUGH
FRIDAY MORNING UNTIL COLD FRONT CLEARS THE AREA. POSSIBLE LOW
LEVEL WIND SHEAR CONDITIONS MAY EXIST OUT AHEAD OF THE COLD FRONT
THURSDAY NIGHT.

LONG TERM...MAINLY VFR CONDITIONS THROUGH MONDAY.

&&

.MARINE...
SHORT TERM...SCA THROUGH FRIDAY AS WINDS WILL GUSTS UP TO 30 KNOTS
OUT AHEAD OF COLD FRONT LATE THURSDAY INTO FRIDAY. ALSO...SWELLS
UP TO 8 FEET ARE EXPECTED DUE TO THE LONG SOUTHERLY FETCH.

LONG TERM...SCA CONDITIONS LIKELY SATURDAY NIGHT INTO MONDAY.

&&

.HYDROLOGY...
EXPECTING A 1.5 TO 2.5 INCH RAINFALL EVENT STARTING TODAY AND
CONTINUING INTO TONIGHT WITH POSSIBLY UP TO 3" IN FAVORABLE
UPSLOPE LOCATIONS. WITH FLASH FLOOD GUIDANCE AT 3 - 3.5 INCHES...NO
FLASH FLOOD WATCH WILL BE ISSUED AT THIS TIME. HOWEVER...URBAN
AND LOW LYING FLOODING IS POSSIBLE. SOME FLASHIER STREAMS MAY SHOW
VERY SHARP RISES AND NOT RULING OUT AN ISOLATED FLASH FLOOD IN
AREAS OF STRONGEST CONVECTION.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...FLASH FLOOD WATCH FROM 6 PM EDT THIS EVENING THROUGH LATE
     TONIGHT FOR MEZ007>009-012>014.
NH...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NHZ002>007.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 8 PM EDT
     FRIDAY FOR ANZ150>154.

&&

$$

NEAR TERM...EKSTER



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