373  
FXUS61 KOKX 190003  
AFDOKX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NEW YORK NY  
703 PM EST SAT JAN 18 2025  
   
SYNOPSIS
 
 
LOW PRESSURE WILL MOVE ACROSS THE AREA THIS EVENING, THEM SLIDE  
EAST TONIGHT. ANOTHER WAVE OF LOW PRESSURE DEVELOPS THE MID  
ATLANTIC COAST ON SUNDAY AND PUSHES NORTHEAST INTO SUNDAY NIGHT.  
ARCTIC AIRMASS BUILDS IN EARLY INTO MIDDLE OF NEXT WEEK WITH  
HIGH PRESSURE BUILDING IN FROM THE WEST. A LOW PRESSURE SYSTEM  
PASSES WELL OFFSHORE MID AND LATE IN THE WEEK. HIGH PRESSURE  
WILL BE MORE OFFSHORE TOWARDS THE END OF NEXT WEEK.  
 

 
   
NEAR TERM /UNTIL 6 AM SUNDAY MORNING/
 
 
LOW PRESSURE AND ASSOCIATED COLD FRONT MOVE ACROSS THE REGION  
THIS EVENING, THEN SLIDE EASTWARD OVERNIGHT.  
 
RAIN WILL CONTINUE ACROSS THE FORECAST AREA THIS EVENING, THEN  
GRADUALLY TAPER OFF TOWARDS MIDNIGHT. BEHIND THE FRONT, DRIER  
CONDITIONS ARE THEN EXPECTED AS WINDS BACK TO THE WEST AND  
EVENTUALLY NORTHWEST LATE. LOWS TONIGHT WILL RANGE FROM THE  
MIDDLE 20S TO LOWER 30S.  
 

 
   
SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/
 
 
*WINTER STORM WARNINGS AND ADVISORIES ARE IN EFFECT.  
 
MAIN FOCUS WILL TURN TO A DEVELOPING LOW PRESSURE SYSTEM OVER THE  
MID-ATLANTIC ON SUNDAY. AS THE LOW PRESSURE SYSTEM GRADUALLY  
STRENGTHENS SUNDAY AFTERNOON, MOISTURE OVERRUNS THE NORTHERN SIDE OF  
THE LOW AND PRECIPITATION BLOSSOMS OVER THE AREA. THIS WILL BE AIDED  
BY LARGE SCALE SYNOPTIC FORCING OVER THE AREA.  
 
DESPITE CONFIDENCE CONTINUING TO INCREASE THAT A QUICK MOVING WINTER  
STORM WILL IMPACT THE REGION, THERE STILL REMAINS QUESTIONS TO THE  
EXACT TRACK OF THE LOW. SUBTLE CHANGES TO THE TRACK THIS SYSTEM WILL  
TAKE, WILL ALSO HAVE IMPACTS ON THE AMOUNT OF SNOW WE SEE.  
 
MOST OF THE 12Z FORECAST GUIDANCE NOW HAS THE LOW PASSING SOUTH AND  
EAST OF LONG ISLAND. ALL THE 12Z GEFS MEMBERS, WHICH WERE CLOSER TO  
THE COAST, SHIFTED A BIT SOUTH AND EAST AND THE 12Z NAM, WHICH HAD  
PREVIOUSLY BEEN FURTHER OFFSHORE, DID SHIFT A BIT CLOSER TO THE  
AREA.  
 
OVERALL, EXPECTING PRECIPITATION TO OVERSPREAD THE REGION AS EARLY  
AS LATE MORNING/EARLY AFTERNOON, WITH LIKELY POPS BY MID TO LATE  
AFTERNOON THROUGH MIDNIGHT. AFTER MIDNIGHT, THE SNOW BEGINS TO TAPER  
OFF AND COME TO AN END.  
 
QPF AMOUNTS ARE GENERALLY GOING TO RANGE FROM 0.40 TO 0.60. EXPECT A  
SWATH OF 5 TO 7 INCHES, WITH LOCALLY HIGHER AMOUNTS POSSIBLE ACROSS  
THE INTERIOR. CLOSER TO THE COAST, AMOUNTS WILL RANGE 3 TO 5 INCHES,  
WITH LOCALLY HIGHER AMOUNTS UP TO 6 POSSIBLE. AS A RESULT, HAVE  
CONVERTED MOST OF THE WINTER STORM WATCH TO A WARNING. THE ONLY  
EXCEPTION WAS EASTERN BERGEN COUNTY. ANYWHERE THERE WAS NO WATCH AND  
EASTERN BERGEN COUNTY, A WINTER WEATHER ADVISORY IS NOW IN EFFECT.  
THESE HEADLINES WILL START AT 1PM SUNDAY AND END AT 4AM MONDAY.  
 
ONE AREA OF CONCERN WAS ACROSS THE COASTAL LOCATIONS, SPECIFICALLY  
LONG ISLAND AND PORTIONS OF COASTAL CONNECTICUT, WHERE I FELT  
TEMPERATURES MAY HAVE BEEN TOO WARM. I DID LOWER TEMPERATURES HERE A  
BIT MAINLY TO ACCOUNT FOR WET BULBING. IF TEMPERATURES ARE  
WARMER THAN FORECAST, WE MAY SEE MORE MIXING OR A SLIGHTLY  
LONGER PERIOD OF RAIN BEFORE A CHANGE OVER TO ALL SNOW OCCURS.  
 
THE LOW DEPARTS THE AREA SUNDAY NIGHT WITH STRONG HIGH PRESSURE  
BUILDING INTO THE AREA.  
 

 
   
LONG TERM /MONDAY THROUGH SATURDAY/
 
 
MAIN POINTS  
 
* ARCTIC COLD AIRMASS ACROSS THE REGION WITH TEMPERATURES NOT  
GETTING TO FREEZING UNTIL FRIDAY FOR MOST LOCATIONS AND NOT ABOVE  
FREEZING FOR UNTIL NEXT SATURDAY FOR MOST LOCATIONS.  
 
* COLDEST HIGH TEMPERATURES FORECAST FOR TUESDAY AND WEDNESDAY WHEN  
HIGHS ONLY REACHING UPPER TEENS TO LOWER 20S.  
 
* COLDEST LOW TEMPERATURES FORECAST TUESDAY NIGHT AND WEDNESDAY  
NIGHT WHEN LOWS PLUMMET TO SINGLE DIGITS TO LOWER TEENS FOR MUCH  
OF THE AREA. SOME LOCATIONS GET TO SUB-ZERO LOW TEMPERATURES.  
 
* SUB-ZERO WIND CHILLS FORECAST FOR MONDAY NIGHT, TUESDAY NIGHT, AND  
MOST LOCATIONS NORTH AND WEST OF NYC FOR WEDNESDAY NIGHT.  
WEDNESDAY NIGHT, ALONG COAST MOSTLY A FEW DEGREES ABOVE ZERO FOR  
WIND CHILLS.  
 
MAIN JET STREAM STAYS SOUTH OF THE REGION MUCH OF THE NEXT WEEK.  
NORTHERLY FLOW IN THE LOW TO MID LEVELS WILL HELP ESTABLISH AN  
ARCTIC AIRMASS BUILDING IN THROUGH MUCH OF THE WEEK. HIGHLY  
AMPLIFIED TROUGH STAYS IN THE NORTHEAST. POTENTIAL MODERATION OF  
THIS AIRMASS BY FRIDAY INTO START OF NEXT WEEKEND WITH POTENTIAL  
UPPER LEVEL PATTERN SHIFT WITH FLATTENING TROUGH IN NORTHEAST.  
 
THE CORE OF THIS ARCTIC AIRMASS WITH COLDEST TEMPERATURES AND WIND  
CHILLS OCCURS IN THE EARLY TO MID PART OF THE WEEK. FORECAST MODEL  
850MB TEMPERATURES DOWN TO NEAR -20 TO -23 MONDAY THROUGH WEDNESDAY.  
THE FORECAST MODELS SHOW AN INCREASE IN 850MB TEMPERATURES THURSDAY  
NEAR -5 TO -10.  
 
ESAT FROM NAEFS SHOWS STANDARD DEVIATIONS OF -2 TO -3 WITH THE 850  
TO 500MB TEMPERATURES WITHIN THE MONDAY THROUGH WEDNESDAY TIMEFRAME  
FOR THE NORTHEAST.  
 
MAIN CHANCE OF SNOW TUESDAY NIGHT INTO WEDNESDAY ALONG THE COAST  
WITH PERIPHERAL PRECIPITATION FROM LOW MOVING WELL OFFSHORE. WOULD  
EXPECT MAINLY DRY CONDITIONS TO PREVAIL. ANOTHER SLIGHT CHANCE OF  
SNOW LATE IN THE WEEK, THURSDAY NIGHT INTO FRIDAY TIME PERIOD.  
 
SURFACE WINDS BECOME LIGHTER FOR MID TO LATE WEEK, ALLOWING FOR WIND  
CHILLS TO BECOME LESS OF A FACTOR. EVENTUAL MODERATION OF THE  
AIRMASS IS FORECAST AS FORECAST HIGH TEMPERATURES THURSDAY REACH FOR  
MAJORITY OF REGION INTO THE LOW TO UPPER 20S, MUCH OF THE REGION  
NEAR 30 FOR FRIDAY, AND THEN LOW TO MID 30S FOR NEXT SATURDAY.  
 

 
   
AVIATION /00Z SUNDAY THROUGH THURSDAY/
 
 
A WEAK FRONTAL WAVE AND/OR WARM FRONT APPROACHES FROM THE  
SOUTHWEST INTO EARLY THIS EVENING. A COLD FRONT THEN PASSES  
THROUGH LATER TONIGHT (03Z-06Z). LOW PRESSURE DEVELOPS ALONG  
THE MID ATLANTIC COAST ON SUNDAY, PASSING TO THE SOUTHEAST OF  
THE AREA SUNDAY NIGHT.  
 
MVFR/IFR WITH PATCHY VFR AS RAIN EXITS THE AREA. WIDESPREAD VFR  
RETURNS FROM ABOUT 02Z TO 04Z AFTER COLD FRONTAL PASSAGE WITH  
W/NW FLOW LESS THAN 10 KT.  
 
FOR SUNDAY, CEILINGS WILL LOWER TO IFR/LIFR IN SNOW DURING THE  
AFTERNOON, PERSISTING INTO SUNDAY EVENING. WINDS WILL BE N/NW  
AROUND 10KT WITH GUSTS DEVELOPING IN THE AFTERNOON AT 15-20KT.  
 
EXPECTED SNOWFALL ACCUMULATIONS:  
 
NYC TERMINALS AND BDR: 4-6"  
ISP: 3-5"  
HPN/SWF: 5-7"  
 
...NY METRO (KEWR/KLGA/KJFK/KTEB) TAF UNCERTAINTY...  
 
TIMING OF CHANGING FLIGHT CATEGORIES WILL LIKELY VARY +/- 1-2  
HOURS.  
   
OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY
 
 
SUNDAY NIGHT: IFR/MVFR BECOMING VFR. NE-N WIND GUSTS 15-20KT IN  
THE EVENING, BECOMING NW 20-25KT OVERNIGHT.  
 
MONDAY: VFR. NW WIND GUSTS 20-25 KT.  
 
TUESDAY: VFR. W WIND GUSTS AROUND 20 KT.  
 
WEDNESDAY: CHANCE OF MVFR OR LOWER IN -SN, PARTICULARLY COASTAL  
TERMINALS.  
 
THURSDAY: VFR.  
 
DETAILED INFORMATION, INCLUDING HOURLY TAF WIND COMPONENT FORECASTS,  
CAN BE FOUND AT: HTTPS:/WWW.WEATHER.GOV/ZNY/N90  
 

 
   
MARINE
 
 
HAVE CANCELLED THE SMALL CRAFT ADVISORY WITH CONDITIONS ON THE AREA  
WATERS GRADUALLY IMPROVING. A BRIEF PERIOD OF SUB-SCA CONDITIONS ARE  
EXPECTED TONIGHT AND SUNDAY. WINDS AND SEAS THEN INCREASE SUNDAY  
NIGHT AS THE LOW PRESSURE PASSES NEARBY. AS THE LOW PULLS AWAY  
SUNDAY NIGHT, SCA CONDITIONS SHOULD PREVAIL ACROSS ALL WATERS WITH A  
GUSTY WNW BEHIND ANOTHER COLD FRONT. THERE WILL BE A LOW END CHANCE  
FOR SOME GALE GUSTS.  
 
MONDAY, WIDESPREAD SCA CONDITIONS EXPECTED FOR ALL WATERS DUE TO  
WIND GUSTS, FOR OCEAN BOTH WIND GUSTS AND SEAS. DECREASING TREND TO  
WINDS AND SEAS MONDAY NIGHT, BUT OCEAN WILL PROBABLY STILL HAVE SCA  
CONDITIONS MUCH OF THE NIGHT. NON-OCEAN WATERS STAY BELOW SCA FOR  
MONDAY NIGHT. THE OCEAN COULD HAVE SOME LINGERING SCA CONDITIONS  
TUESDAY MORNING WITH OTHERWISE BELOW SCA CONDITIONS FOR THE WATERS.  
FOR TUESDAY AFTERNOON THROUGH THURSDAY, SUB-SCA CONDITIONS FORECAST.  
 
ALSO, WOULD SOME DEGREE OF FREEZING SPRAY FOR MONDAY INTO TUESDAY  
FOR PARTS OF THE WATERS.  
 

 
   
HYDROLOGY
 
 
NO HYDROLOGIC ISSUES ARE ANTICIPATED THROUGH SATURDAY.  
 

 
   
OKX WATCHES/WARNINGS/ADVISORIES
 
 
CT...WINTER STORM WARNING FROM 1 PM SUNDAY TO 4 AM EST MONDAY FOR  
CTZ005>007.  
WINTER WEATHER ADVISORY FROM 1 PM SUNDAY TO 4 AM EST MONDAY  
FOR CTZ008>012.  
NY...WINTER STORM WARNING FROM 1 PM SUNDAY TO 4 AM EST MONDAY FOR  
NYZ067>070.  
WINTER WEATHER ADVISORY FROM 1 PM SUNDAY TO 4 AM EST MONDAY  
FOR NYZ071>075-078>081-176>179.  
NJ...WINTER STORM WARNING FROM 1 PM SUNDAY TO 4 AM EST MONDAY FOR  
NJZ002-004-103-105-107.  
WINTER WEATHER ADVISORY FROM 1 PM SUNDAY TO 4 AM EST MONDAY  
FOR NJZ006-104-106-108.  
MARINE...SMALL CRAFT ADVISORY FROM 6 PM SUNDAY TO 6 PM EST MONDAY FOR  
ANZ331-332-335-338-340-345-350-353-355.  
 

 
 

 
 
SYNOPSIS...BC/JM  
NEAR TERM...BC  
SHORT TERM...BC  
LONG TERM...JM  
AVIATION...JP  
MARINE...BC/JM  
HYDROLOGY...BC/JM  
 
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