Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
141 AM EST WED JAN 28 2015

.SYNOPSIS...
HIGH PRESSURE BUILDS IN TODAY BEHIND THE NOR'EASTER. THE HIGH MOVES
OFF THE COAST THURSDAY AS A CLIPPER SYSTEM APPROACHES FROM THE
NORTHWEST. THIS LOW WILL AFFECT THE AREA THURSDAY NIGHT AND USHER
IN VERY COLD AIR ON FRIDAY. HIGH PRESSURE BUILDS IN FROM THE WEST
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THEN SLIDES TO THE EAST ON
SUNDAY. A STORM SYSTEM APPROACHES FROM THE SOUTHWEST LATE
SUNDAY...THEN PASSES JUST SOUTH OF THE AREA MONDAY...THEN EXITS TO
THE NORTHEAST MONDAY NIGHT. HIGH PRESSURE THEN BUILDS IN ON
TUESDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LIGHT SNOW FINALLY DIMINISHING OVER SOUTHERN CT AND MOST OF SUFFOLK
COUNTY. ACTIVITY IS BEST DETECTED BY THE LATEST RAP. ALL INDICATIONS
ARE THAT THIS DISSIPATES BEFORE SUNRISE. THE KOKX RADAR SHOWED AN
ENHANCED AREA PASSING RIGHT OVER THE OFFICE WHERE 1/2" WAS
MEASURED AT 06Z. WOULD SUSPECT THAT THE TWIN FORK MAY HAVE PICKED
UP AN INCH.

WILL ISSUE A SPECIAL WEATHER STATEMENT TO ENSURE DOT FOLKS ARE
AWARE OF THIS.  

WINDS GUSTING TO 25 MPH WILL RESULT IN SOME BLOWING SNOW.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
UPPER TROUGH DEPARTS WITH RIDGE BUILDING IN LATE WEDNESDAY AND
WEDNESDAY NIGHT. DRY WEATHER IS EXPECTED...WITH GUSTY NW WINDS
PERSISTING. THESE WINDS...COMBINED WITH CHILLY TEMPS WILL PRODUCE
WIND CHILL READINGS IN THE SINGLE DIGITS TO TEENS.

MORNING CLOUDS GIVE WAY TO SUNSHINE FROM WEST TO EAST.

HIGH TEMPS MID 20S TO AROUND 30...WITH LOWS FROM ZERO TO THE
TEENS. GOOD RADIATIONAL COOLING CONDITIONS ARE ANTICIPATED DUE TO
CLEAR SKIES...LIGHTENING WINDS AND SNOW COVER.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
NORTHERN STREAM RIDGING EXITS TO THE EAST ON THURSDAY...WITH A 
NORTHERN STREAM SHORTWAVE QUICK ON ITS HEELS. FOR NOW APPEARS 
THURSDAY SHOULD BE DRY...EXCEPT FOR A SLIGHT CHANCE OF LIGHT SNOW 
LATE IN THE AFTERNOON OVER FAR WESTERN ZONES. THIS SHORTWAVE LIFTS 
THROUGH THURSDAY NIGHT FOLLOWED BY THE APPROACH OF A DEEPER FULL 
LATITUDE TROUGH...WHOSE AXIS CROSSES THE AREA ON FRIDAY.HAVE LIKELY 
POPS FOR LIGHT SNOW AS A RESULT THURSDAY NIGHT WITH THE 
SHORTWAVE...THEN CHANCE POPS ON FRIDAY WITH THE UPPER TROUGH. AT 
THIS TIME IT APPEARS THAT THE AREA WILL EXPERIENCE A SUB-ADVISORY 
(LESS THAN 3 INCH) SNOWFALL FROM THURSDAY NIGHT THROUGH FRIDAY.

FOR HIGHS ON THURSDAY A BLEND OF MAV/MET/ECS GUIDANCE...WITH NAM 
2-METER TEMPERATURES AND A MIX DOWN FROM 975 HPA PER BUFKIT 
SOUNDINGS WERE USED. HIGHS SHOULD BE AROUND 5 DEGREES BELOW NORMAL.
THE MINIMUM OF MAV/MET GUIDANCE...THE PREVIOUS FORECAST AND NAM 
2-METER TEMPERATURES WAS USED FOR LOWS ON THURSDAY NIGHT...THEN A 
DEGREE WAS SUBTRACTED TO REFLECT THE INFLUENCE OF SNOW COVER. LOWS 
SHOULD BE SLIGHTLY ABOVE NORMAL. FOR HIGHS ON FRIDAY A BLEND OF 
MEX/MEN/EKD/ECE/ECM/WPC GUIDANCE WITH NAM 2-METER TEMPERATURES AND A 
MIX DOWN FROM 900-875 HPA WAS USED...WITH VALUES FORECAST TO BE A 
FEW DEGREES BELOW NORMAL.

DEEP LAYERED RIDGING BUILDS IN FRIDAY NIGHT THROUGH SATURDAY 
NIGHT...WITH ITS RIDGE AXIS SLIDING TO THE EAST ON SUNDAY. IT SHOULD 
BE DRY FRIDAY NIGHT-SATURDAY NIGHT DUE TO SUBSIDENCE UNDERNEATH THE 
RIDGE.

THERE ARE SOME DIFFERENCES IN SOLUTIONS FOR A STORM SYSTEM FORECAST 
TO IMPACT THE AREA EARLY NEXT WEEK. THE ECMWF IS THE WARMEST 
SOLUTION...THE CANADIAN THE COLDEST AND FASTEST...AND THE GFS IN 
BETWEEN. NOTING THE GEFS ENSEMBLE MEAN SUPPORTS A SOLUTION TO THE SE 
OF THE GFS...LEANED TOWARDS A SLIGHTLY COOLER VERSION OF THE GFS 
SOLUTION. SO HAVE A RAIN SNOW MIX NEAR THE COAST AND SNOW ACROSS THE 
INTERIOR FROM LATE SUNDAY INTO MONDAY. 

RIDGING BEGINS TO BUILD IN MONDAY NIGHT AND TUESDAY...WITH A DRY 
FORECAST AS A RESULT.

FOR TEMPERATURES FRIDAY NIGHT-TUESDAY A BLEND OF 
MEX/MEN/EKD/ECE/ECM/WPC GUIDANCE WAS USED WITH TEMPERATURES FORECAST 
TO BE BELOW NORMAL DURING THIS TIME FRAME.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
LOW PRES E OF CAPE COD WILL DRIFT NWD THROUGH THE GULF OF MAINE AND 
INTO THE MARITIMES ON WED.

MAINLY VFR ACROSS NYC/NJ METRO AND WESTERN TERMINALS THROUGH TAF
PERIOD. BDR/KISP WILL SEE MVFR CONDS...POSSIBLY BRIEF
IFR...THROUGH AROUND 08Z WITH SNOW SHOWERS...THEN MAINLY VFR. LOW 
PROBABILITY OF MVFR CIGS TODAY...MORE LIKELY FEW-SCT 2500 FT.

MVFR CONDS AT KGON EARLY THIS MORNING IN -SN...BRIEF IFR CONDS 
POSSIBLE. LIGHT SNOW BANDS DIMINISH TOWARDS DAYBREAK...BUT SCT-BKN 
MVFR CIGS COULD LINGER INTO WEDNESDAY.

NW WINDS GENERALLY AROUND 330-360 MAGNETIC THRU THE TAF PERIOD. 
GUSTS MAY BECOME OCCASIONAL FOR WESTERN TERMINALS OVERNIGHT...BUT 
SHOULD BECOME FREQUENT ONCE AGAIN AFTER 14Z WEDNESDAY.

.OUTLOOK FOR 00Z THURSDAY THROUGH SATURDAY...
.WED NIGHT...VFR. DIMINISHING WINDS.
.THU NGT...MVFR OR LOWER IN SNOW. 
.FRI...MVFR POSSIBLE IN THE MRNG WITH SNOW. NW WINDS 20-30KT.
.SAT...VFR.
.SUN...MVFR OR LOWER POSSIBLE.

&&

.MARINE...
DEEP LOW PRESSURE EAST OF CAPE COD WILL DEPART TO THE NORTHEAST AS
HIGH PRESSURE GRADUALLY BUILDS IN FROM THE WEST.

SCA GUSTS CONTINUE OVERNIGHT AND THROUGH WEDNESDAY FOR ALL WATERS.
SEAS GRADUALLY SUBSIDE...BUT REMAINS RATHER ROUGH THROUGH
WEDNESDAY.

WINDS DIMINISH FURTHER WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS.

A RELATIVELY RELAXED PRESSURE GRADIENT WILL PRODUCE SUB-SMALL CRAFT 
CONDITIONS OVER THE WATERS THURSDAY AND THURSDAY EVENING. THE 
PRESSURE GRADIENT BEGINS TO INCREASE THURSDAY NIGHT...WITH AT LEAST 
SCA LEVEL SEAS POSSIBLE ON THE COASTAL WATERS LATE THURSDAY NIGHT.

A TIGHTENING PRESSURE GRADIENT AND STRONG LOW LEVEL COLD ADVECTION 
MAKES GALE CONDITIONS PROBABLE ON ALL WATERS FROM FRIDAY AND FRIDAY 
NIGHT. 

WINDS DIMINISH SATURDAY AS HIGH PRESSURE BUILDS IN...WITH ONLY SCA 
LEVEL SEAS POSSIBLE ON THE COASTAL OCEAN WATERS BY AFTERNOON. SUB 
SCA CONDITIONS SHOULD DEVELOP ON ALL WATERS BY LATE SATURDAY 
NIGHT...AND CONTINUE ON SUNDAY...WITH A RELAXED PRESSURE GRADIENT 
FORECAST TO BE OVER THE REGION.

&&

.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION THROUGH SUNDAY. SOME LIGHT SNOW IS
LIKELY THURSDAY NIGHT AND FRIDAY...BUT NO HYDROLOGIC IMPACT IS
EXPECTED.

THERE IS THE POTENTIAL FOR AT LEAST A HALF AN INCH OF LIQUID 
EQUIVALENT TO FALL FROM LATE SUNDAY INTO MONDAY. SOME OR MOST OF
THIS IS CURRENTLY FORECAST TO BE IN THE FORM OF FROZEN
PRECIPITATION...SO LITTLE OR NO HYDROLOGIC IMPACT IS EXPECTED AT
THIS TIME. HOWEVER...IF THE WARMEST SOLUTION WITH THIS SYSTEM
VERIFIES...THEN MOST OF THIS COULD BE OF LIQUID FORM...AND COULD
PRODUCE HYDROLOGIC CONCERNS...ESPECIALLY OVER AREAS JUST RECEIVING
A FOOT OR MORE OF SNOW.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ330-
     335-338-340-345-350-353-355.

&&

$$
SYNOPSIS...MALOIT/PW
NEAR TERM...TONGUE
SHORT TERM...PW
LONG TERM...MALOIT
AVIATION...GOODMAN
MARINE...MALOIT/TONGUE/PW
HYDROLOGY...MALOIT/PW




National Weather Service Glossary of Abbreviations