Skip Navigation Linkswww.nws.noaa.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service Forecast Office   NWS logo - Click to go to the NWS homepage
Gray/Portland banner image
 
 

Area Forecast Discussion
Latest Versions  [Current][-1][-2][-3][-4]



000
FXUS61 KGYX 220834
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
334 AM EST MON DEC 22 2014

.SYNOPSIS...
AN ONSHORE FLOW MAY PRODUCE SOME FLURRIES OR LIGHT SNOW MAINLY
OVER SOUTHERN REGIONS RIGHT THROUGH TUESDAY. A SIGNIFICANT LOW
PRESSURE SYSTEM WILL GRADUALLY ORGANIZE WEDNESDAY...BEFORE MOVING
OVER THE GREAT LAKES. THIS COULD BRING WINDY CONDITIONS AND THE
POTENTIAL FOR HEAVY RAIN AROUND CHRISTMAS EVE INTO EARLY CHRISTMAS
MORNING. ANOTHER LOW PRESSURE SYSTEM WILL PASS BY TO OUR NORTHWEST
LATE IN THE WEEK AND EARLY NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
AT 07Z...A 1032 MILLIBAR HIGH WAS CENTERED VICINITY OF THE GASPE
PENINSULA. THE HIGH WILL GRADUALLY RETREAT TO THE NORTHEAST
TODAY. COLD ONSHORE FLOW AROUND THIS HIGH WILL PRODUCE SOME
SCATTERED OCEAN EFFECT SNOW SHOWERS OR FLURRIES TODAY MAINLY
ACROSS SOUTHERN AND COASTAL SECTIONS TODAY.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM TUESDAY/...
SCATTERED SNOW SHOWERS AND FLURRIES WILL CONTINUE THROUGH TONIGHT
BECAUSE OF THE PERSISTENT ONSHORE FLOW. COLD AIR DAMMING SHOULD
KEEP THE COLUMN COLD ENOUGH TONIGHT FOR ANY LIGHT PRECIPITATION TO
FALL LARGELY AS SNOW. 

BY TUESDAY MORNING...WARM AIR ADVECTION PRECIPITATION AHEAD OF THE
MIDWEST STORM SYSTEM SHOULD BEGIN TO OVERSPREAD THE FORECAST AREA
FROM SOUTH TO NORTH. THERE COULD BE A BRIEF PERIOD OF LIGHT
FREEZING DRIZZLE OR RAIN AS THE WARMER AIR BEGINS TO OVERSPREAD
THE AREA...AS MODELS HINT AT COLD AIR DAMMING ACROSS THE INTERIOR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
EXTENDED PERIOD WX TO BE DRIVEN BY SERIES OF DOWNSTREAM BLOCKS OVER
THE ATLANTIC AND EUROPE...WHICH WILL HELP BUILD RIDGING AND HIGHER
AMPLITUDE THROUGH THE WEEK AND INTO EARLY NEXT WEEKEND...BEFORE
THERE ARE SIGNS OF THE BLOCKING BREAKING DOWN AND ALLOWING COLDER
AIR TO MOVE IN.

WE START THE PERIOD DURING THE CHRISTMAS HOLIDAY PERIOD AND THE
PREVIOUSLY ADVERTISED STORM SYSTEM THAT WILL THE CWA WED INTO THU.
MOST OF THE SHORT TO MEDIUM RANGE MODELS HAVE INTRODUCED AN
IMPORTANT CHANGE TO THE FORECAST...AND THAT ALLOWS THE FIRST NRN
STREAM 500MB WAVE TO PASS BY WITH OUT MUCH INTERACTION WITH THE
LARGER SCALE TROUGH...WHICH LINGERS OVER THE GULF STATES UNTIL
EARLY WED MORNING. THIS WOULD MAKE FOR A LESS IMPRESSIVE SFC LOW
THAT INTENSIFIES LATER AND FURTHER N...WHICH WOULD LIMIT THE
DEVELOPMENT OF THE LOW LVL JET...AND THEREFORE BRING DOWN
QPF...AND ALSO LOWER THE HTREAT FRO STRONG WINDS. THIS SCENARIO IS
SUPPORTED BY THE 00Z EURO AND GFS...AND TO SOME DEGREE THE
NAM...ALTHOUGH THAT REALLY HOLDS BACK THE 500 MB CLOSED LOW. THE
00Z CMC HEMI IS THE ONE MODEL THAT TEND TOWARD BETTER PHASING AND
HOLDS ONTO A STRONGER SINGLE SFC LOW. THESE CHANGES IN THE MODELS
MAY BE THE RESULT ONE OR ALL OF THE WAVES INVOLVED IN GETTING THIS
STORM TOGETHER HAVE MOVES INTO A MORE WELL SAMPLED PART OF THE
MODEL DOMAIN. THERES ALSO STILL THE ISSUE OF DEEP CONVECTION IN
THE FORECAST TUE AFFECTING THE MODELS AS WELL. GIVEN ALL THAT WILL
BE STICKING CLOSER TO THE GFS/EURO...AND BLENDING BACK IN SOME OF
THE PREVIOUS FORECAST...PARTIALLY FOR THE SAKE OF CONTINUITY.

OVERALL...THE SAME ISSUES PREVAIL FROM PREVIOUS
FORECASTS...ALTHOUGH TO A LESSER DEGREE...AND IT WILL PRETTY MUCH
BE PRECIPITATING /MOSTLY RAIN/ FROM TUESDAY RIGHT INTO CHRISTMAS
MORNING. THE FIRST CHANGE IN THE FORECAST WILL BE THAT THE COLDER
AIR WILL HANG ON LONGER...INTO WED MORNING. IN MOST PLACES TEMPS
WILL BE ABV FREEZING THRU TUE NIGHT...BUT WE COULD SEE A PERIOD
OF FZRA IN THE MTNS...WITH A TENTH OR TWO OF ICE ACCUMS BEFORE
TEMPS RISE ABV THERE BY MIDDAY. S WINDS WILL PICK UP...BUT NOT
UNTIL LATER IN THE DAY WED...AND WILL LKLY NOT BE AS GUSTY WED
NIGHT...BUT COULD GUST TO 30 MPH OR IN THE W FLOW BEHIND THE LOW
ON THU. QPF WAS LOWERED TOO...BUT STILL WILL SEE A PERIOD OF HEAVY
RAIN...BUT THAT WILL PROBABLY BE LIMITED TO WED NIGHT. QPF AROUND
2 INCHES ACROSS THE CWA...LOWEST N OF THE MTNS AND HIGHEST IN THE
UPSLOPE AREAS. ALSO...THE WARMER AIR WILL NOT COME IN AS QUICKLY
AND THIS WILL HELP LIMIT SNOW MELT AND THUS MITIGATING THE
FLOODING THREAT SOME. STILL...WILL SEE ENOUGH RAIN THAT SOME
FLOODING PROBLEMS ARE POSSIBLE. FINALLY TEMPS WILL PUSH UP INTO
THE 50S IN THE SRN ZONES...WITH THE WARMEST READINGS LKLY WED
NIGHT INTO THU MORNING.

ALTHOUGH IT COOLS DOWN SOMEWHAT BEHIND THEIS SYSTEM...TEMPS WILL
REMAIN ABV NORMAL...BY 5-10F FRI AND SAT AS HIGH PRES BUILDS IN.
NEXT CHC FOR ANY SIGNIF PRECIP WILL BE LATE IN THE WEEKEND.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
SHORT TERM...MAINLY VFR THROUGH TONIGHT...HOWEVER THERE MAY BE
BRIEFLY MVFR CONDITIONS IN SCATTERED SNOW SHOWERS SOUTHERN
LOCATIONS. MVFR CONDS EXPECTED FOR TUE.

LONG TERM...EXTENDED PERIOD OF FLIGHT RESTRICTIONS TUS NIGHT INTO
THU MORNING. LOOK FOR IFR OR LOWER TUE NIGHT...WITH SOME
IMPROVEMENT TO MVFR DURING THE DAY WED...AND A RETURN TO IFR WED
NIGHT. EXPECT IMPROVEMENT TO VFR THU AFTERNOON...WHICH SHOULD
HOLD THRU FRIDAY.

&&

.MARINE...
SHORT TERM...WINDS AND SEAS WILL REMAIN BELOW SCA CONDITIONS
THROUGH LATE TONIGHT. AN SCA WILL LIKELY BE NEEDED BY TUESDAY IN
INCREASING WINDS AND SEAS.

LONG TERM...MODELS CONTINUE TO BACK OFF THE STRONG WINDS WED INTO
THU...BUT STILL EXPECT A PERIOD OF GALES...POSSIBLE IN THE S FLOW
LATE WED AND WED NIGHT...BUT MORE LKLY IN STRONG W FLOW THU INTO
THU NIGHT.

&&

.HYDROLOGY...
MODELS CONTINUE TO BACK OFF ON RAINFALL TOTALS FOR
THE CHRISTMAS EVE/EARLY CHRISTMAS MORNING EVENT...BUT AREA STILL
AROUND 2 INCHES. HOPING THE SNOWPACK IN THE MOUNTAINS AND
FOOTHILLS WILL TAKE IN SOME OF THE RAINFALL IN THAT AREA...BUT
STILL EXPECT SOME RAPID RISES IN THE HEADWATERS. IN ANY
CASE...WHILE THE THREAT OF FLOODING IS LOWER...IT STILL REMAINS A
POSSIBILITY WED NIGHT INTO THU.

&&

.TIDES/COASTAL FLOODING...
ASTRONOMICAL TIDES ARE AT THEIR PEAK FOR THE MONTH. THIS...IN
COMBINATION WITH STRONG SOUTHERLY GALES WILL LIKELY ALLOW FOR
SOME STORM SURGE. WAVES PROB NOT QUITE AS HIGH AS PREV
FORECASTS...MAYBE 10 TO 12 FT...BUT THERE IS SOME POTENTIAL FOR
MINOR COASTAL FLOODING...WITH SPLASH OVER AND BEACH EROSION
DISTINCT POSSIBILITY.


&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$
SCHWIBS/CEMPA



National Weather Service
Disclaimer Privacy Policy