658  
FXUS61 KGYX 220840  
AFDGYX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAY ME  
340 AM EST THU FEB 22 2018  
   
SYNOPSIS
 
 
CANADIAN HIGH PRESSURE BUILDS SOUTH INTO THE REGION TODAY WITH  
COOLER AIR ALTHOUGH A WEAK WEATHER SYSTEM PASSING SOUTH OF THE  
REGION TODAY MAY SPREAD SOME LIGHT RAIN AND SNOW TO SOUTHERN  
AREAS BEFORE HIGH PRESSURE BUILDS OVERHEAD TONIGHT THROUGH  
EARLY FRIDAY. A SERIES OF WEATHER SYSTEMS WILL MOVE THROUGH THE  
REGION BEGINNING LATE FRIDAY AND CONTINUING THROUGH THE WEEKEND  
WITH MIXTURE OF PRECIPITATION. FAIR WEATHER RETURNS FOR EARLY  
NEXT WEEK.  
 

 
   
NEAR TERM /THROUGH TODAY/
 
 
FALLING TEMPS CONTINUE THIS EARLY AM, AND MAY SEE A LITTLE SURGE  
IN TEMPS THIS MORNING, BUT THAT WILL LIKELY BE IT AS CLOUDS  
MOVE IN ACROSS MOST OF THE CWA THIS AFTERNOON. STALLED COLD  
FRONT WILL SIT OVER SRN NEW ENGLAND TODAY, WHICH WILL BE  
SPILLING CLOUDS NORTHWARD AS WEAK WAVE MOVE ALONG IT THIS  
AFTERNOON. THIS WILL BRING SOME LIGHT PRECIP INTO SOUTHERN ZONES  
THIS AFTERNOON AS WELL. STEADY PRECIP IS EXPECTED ACROSS THE  
SRN TIER OF NH COUNTIES ALONG THE MA BORDER. THIS COULD START  
AS A RAIN OR A MIX OF SNOW AND RAIN MIDDAY TO EARLY AFTERNOON,  
BUT WILL LIKELY BECOME MAINLY SNOW AS EVAP COOLING LOWERS THE BL  
AND SFC TEMPS INTO THE LOW TO MID 30S. FURTHER NORTH, INTO  
SULLIVAN/MERRIMACK/STRAFFORD/YORK COUNTIES, COULD SEE SOME  
SHRASN AS WELL THIS AFTERNOON, AND EVEN A LITTLE NORTH WOULD  
NOT BE SURPRISED TO SEE A COUPLE SHRASN. GIVEN THE WARM  
ANTECEDENT CONDITIONS, AND THE DRY AIR IN LOWER LEVELS, ANY  
SNOW WILL HAVE TROUBLE ACCUMULATING, ESPECIALLY AT ONSET. THINK  
THE BEST CHANCE TO SEE AROUND INCH OR SNOW WILL BE IN CHESHIRE  
COUNTY AND HILLSBOROUGH WEST OF THE MERRIMACK VLY. FURTHER EAST  
AROUND MHT/ASH AND EASTWARD TOWARD THE COAST, MAY SEE A COATING  
IN SOME SPOTS.  
 

 
   
SHORT TERM /TONIGHT THROUGH 6 PM FRIDAY/
 
 
FOR THE MOST PART, ANY PRECIP SHOULD BE ENDING BY 6PM OR SO, AND  
SKIES WILL CLEAR DURING THE EVENING AS SFC HIGH BUILDS IN FROM  
THE WEST. SHOULD SEE A PERIOD OF DECENT RAD COOLING AS WINDS  
BECOME LIGHT, ESPECIALLY IN THE MTNS, WHERE LOWS WILL DROP INTO  
THE SINGLE DIGITS. ELSEWHERE, LOOK FOR LOWS MOSTLY IN THE 15-25  
RANGE.  
 
FRIDAY WILL START OFF MAINLY SUNNY, BUT CLOUDS WILL BEGIN TO  
INCREASE FROM SW-NE DURING THE MIDDAY, WITH OVC EXPECTED IN THE  
AFTERNOON. ANY PRECIP LOOKS TO HOLD OFF UNTIL THE AFTERNOON, AS  
TWO WEAK WAVES TRY TO MOVE THRU 500 MB RIDGING ALOFT. ALTHOUGH  
WEAK SFC LOW DOES DEVELOP TO OUR N LATE IN THE DAY. DYNAMICALLY,  
THESE ARE WEAK WAVES, BUT THEY DO GENERATE A BROAD AREA OF WAA,  
SO SHOULD SEE SOME PRECIP MOVING EVENTUALLY, BUT MAY NOT BE  
UNTIL LATE. WILL ALSO FLOW TURN ONSHORE OUT OF THE SE, SO THIS  
WILL WARM BOUNDARY ENOUGH ACROSS MOST OF THE COASTAL FOR RAIN OR  
A RAIN/SNOW MIX, WITH TEMPS HERE GENERALLY IN THE MID TO  
UPPER 30S, NOT LOOKING FOR MUCH IN ACCUMS, IF ANYTHING, OUTSIDE  
THE MOUNTAINS AND FOOTHILLS LATE IN THE DAY FRIDAY. COULD SEE A  
COATING TO HALF INCH IN THE NORTH. BEST CHANCE FOR WINTRY  
PRECIP WILL BE FRIDAY NIGHT.  
 

 
   
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/
 
 
A DEVELOPING FAST MOVING WEST TO SOUTHWEST FLOW ALOFT FRIDAY  
NIGHT WILL ALLOW A WEAK SHORT TO MOVE ACROSS NORTHERN NEW  
ENGLAND WITH SOME VERY LIGHT MIXED OVERRUNNING WAA PRECIPITATION.  
NO ACCUMULATIONS OF SNOW ARE EXPECTED WITH THIS SYSTEM WITH  
POSSIBLY SOME VERY LIGHT ICING IN THE MOUNTAINS. THE SYSTEM  
QUICKLY EXITS BY SATURDAY MORNING AS A WEAK SHORT WAVE RIDGE  
BUILDS OVER THE AREA ON DOWNSLOPING NORTHWEST SURFACE WINDS  
ALLOWING SKIES TO BECOME MOSTLY SUNNY OVER MOST AREAS. TEMPS ON  
SATURDAY WILL BE RATHER MILD WITH HIGHS IN THE 40S MOST AREAS  
AND NEAR 50 OVER SOUTHERN NH AND SOUTHWEST ME.  
 
SAT NIGHT CANADIAN HIGH PRESSURE BECOMES CENTERED NORTH OF MAINE  
IN THE MARITIMES AND ALLOWS COLD AIR TO DRAIN SOUTH ACROSS THE  
REGION. MODELS SHOW THIS COLD AIR DAMMING SETTING UP NICELY BY  
SUNDAY MORNING IN ADVANCE OF THE NEXT RAPIDLY APPROACHING WAA  
PATTERN THAT APPROACHES FROM THE SOUTHWEST. SUNDAY WILL BE A MIXED  
PTYPE EVENT WITH SOME LIGHT ACCUMULATIONS OF SNOW OVER SOUTHERN  
AND CENTRAL AREAS BEFORE A CHANGEOVER TO THE MIXED  
PRECIPITATION AND EVENTUALLY RAIN. OVER THE WESTERN MOUNTAINS  
AND FOOTHILLS OF MAINE ENOUGH COLD AIR MAY REMAIN IN PLACE FOR  
MORE SIGNIFICANT ACCUMULATIONS OF SNOW TO OCCUR BEFORE ANY MIX  
OCCURS. THIS SYSTEM WILL ALSO BE A FAST MOVER AND WILL EXIT THE  
AREA BY LATER SUNDAY NIGHT.  
 
EARLY TO MIDWEEK A MORE WESTERLY DRIER FLOW ALOFT IS EXPECTED SO  
GENERALLY FAIR WEATHER IS FORECAST FOR THE LATTER PERIODS.  
 
STAYED CLOSE TO MODEL BLEND GUIDANCE FOR TEMPS THROUGH THE  
OUTLOOK PERIOD.  
 

 
   
AVIATION /08Z THURSDAY THROUGH MONDAY/
 
 
SHORT TERM...MAINLY VFR TODAY, WITH THE EXCEPTION OF KMHT/KPSM,  
AND MAYBE KCON, WHERE WILL SEE MVFR OR IFR RESTRICTIONS IN SN  
OR A SNRA MIX FOR SEVERAL HOURS THIS AFTERNOON. VFR EXPECTED  
INTO FRIDAY MORNING, WITH SOME FLIGHT RESTRICTIONS, LIKELY  
MVFR, POSSIBLE DURING THE AFTERNOON IN SHRASN.  
 
LONG TERM...IFR TO LIFR CONDITIONS POSSIBLE FRIDAY NIGHT IN SOME  
MIXED LIGHT PRECIPITATION THEN IMPROVING TO VFR SATURDAY. SNOW  
AND MIXED PRECIPITATION DEVELOPS FROM S-N SUNDAY LOWERING  
CONDITIONS TO IFR/LIFR. SOME BRIEF PERIODS OF FREEZING RAIN IS  
ALSO A POSSIBILITY ON SUNDAY. CONDITIONS RETURN TO VFR BY LATER  
SUNDAY NIGHT AND CONTINUE THROUGH MONDAY.  
 

 
   
MARINE
 
 
SHORT TERM...WILL HOLD ONTO THE SCA FOR A FEW MORE HOURS FOR  
BORDERLINE WINDS AND SEAS, BUT SHOULD BE ABLE TO BE DROPPED AT  
OR BEFORE ITS CURRENT 13Z EXPIRATION TIME. OTHERWISE SHOULD STAY  
BELOW SCA CRITERIA THROUGH FRIDAY.  
 
LONG TERM...SCAS LIKELY OVER THE OUTER WATERS FRIDAY NIGHT AND  
AGAIN SUNDAY THROUGH MONDAY.  
 

 
   
HYDROLOGY
 
 
FOR THE MOST PART ANY SURGE IN RIVER FLOW DUE TO SNOW MELT IS  
HAPPENING NOW, AND RIVERS WILL RECEDE TODAY. ICE JAM IS STILL  
HOLDING THE CT RIVER AT NORTH STRATFORD ABOVE FLOOD STAGE, AND  
ANOTHER JAM IS ALSO EVIDENT ON THE WARNER RIVER AT DAVISVILLE,  
BUT THIS IS HOLDING BELOW FLOOD.  
 

 
   
GYX WATCHES/WARNINGS/ADVISORIES
 
 
ME...NONE.  
NH...NONE.  
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EST THIS MORNING FOR ANZ150-  
152-154.  
 

 
 

 
 
 
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