421
FXUS61 KALY 180530
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1230 AM EST WED DEC 18 2024
SYNOPSIS
A FAST MOVING STORM SYSTEM WILL RETURN THE THREAT FOR
RAIN AND HIGHER ELEVATION SNOW TO THE REGION FOR THIS AFTERNOON INTO
TONIGHT. DRIER AND MORE SEASONABLE WEATHER IS EXPECTED FOR THURSDAY
BEFORE WIDESPREAD SNOW SHOWERS MOVE INTO THE AREA FOR FRIDAY INTO
FRIDAY NIGHT. MUCH COLDER TEMPERATURES ARE EXPECTED ACROSS THE
REGION FOR THE WEEKEND.
NEAR TERM /UNTIL 6 AM THIS MORNING/
AS OF 1230 AM EST...IR SATELLITE IMAGERY SHOWS FAIRLY
WIDESPREAD STRAOTCU CLOUDS OVER THE NORTHERN HALF OF THE AREA,
THANKS TO THE WEST TO SOUTHWEST FLOW IN PLACE ALOFT. A WEAK
LAKE RESPONSE IS ONGOING, WITH JUST SOME SPOTTY SHALLOW
SPRINKLES AND FLURRIES IMPACTING THE ADIRONDACKS, MOHAWK VALLEY
AND SARATOGA REGION. MEANWHILE, SKIES ARE MORE CLEAR TO THE
SOUTH, AS HIGH PRESSURE IN PLACE OVER THE NORTHERN MID ATLANTIC
IS PROVIDING SOME SUBSIDENCE. ANY PRECIP IS VERY LIGHT, FAIRLY
BRIEF AND WON'T AMOUNT TO MUCH AT ALL.
THE WEAK LAKE EFFECT ACTIVITY SHOULD DIMINISH BY THE LATE NIGHT
HOURS, BUT THE TRAPPED LOW LEVEL MOISTURE WILL KEEP A MOSTLY
CLOUDY TO OVERCAST SKY ACROSS MUCH OF THE AREA. FOR AREAS THAT
SEE MORE CLEARING, THERE COULD BE SOME PATCHY FOG THAT TRIES TO
DEVELOP ACROSS FAR SOUTHERN AREAS, OTHERWISE, SKIES WILL BE
PARTLY TO MOSTLY CLEAR FOR THE CATSKILLS, MID HUDSON VALLEY AND
NW CT.
OVERNIGHT LOWS WILL RANGE FROM THE UPPER 20S OVER THE HIGH
TERRAIN TO THE MID 30S IN VALLEY AREAS.
SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/
KEY MESSAGE: LIGHT SNOW TOTALING 0.5 TO 2 INCHES ACROSS THE
HIGHER ELEVATIONS OF EASTERN NEW YORK AND WESTERN NEW ENGLAND IS
LIKELY WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT.
DRY CONDITIONS PERSIST THROUGH TOMORROW MORNING AS GEOPOTENTIAL
HEIGHTS RISE SLIGHTLY IN RESPONSE TO THE OUTER REACHES OF A SURFACE
HIGH NOSING INTO THE REGION AS ITS CORE SLIDES EASTWARD JUST TO OUR
SOUTH. DESPITE DRY CONDITIONS, CLOUDS WILL BE ON THE INCREASE AHEAD
OF THE NEXT SYSTEM TO BRING WIDESPREAD PRECIPITATION TO THE REGION
TOMORROW AFTERNOON INTO TOMORROW NIGHT. HIGH TEMPERATURES TOMORROW
WILL REACH THE MID/UPPER 30S TO LOW 40S WITH AREAS OF LOW 30S ACROSS
HIGHER TERRAIN. LOW TEMPERATURES TOMORROW NIGHT WILL THEN FALL THE
MID 20S TO LOW 30S.
BY TOMORROW MORNING, A POSITIVELY-TILTED SHORTWAVE WILL BE DIGGING
SOUTH AND EAST INTO THE UPPER-MIDWEST ABOUT THE SOUTHERN PERIPHERY
OF AN UPPER LOW IN THE HUDSON BAY AREA AS SURFACE LOW PRESSURE
ORGANIZES IN THE TENNESSEE VALLEY. AS THE SHORTWAVE DIGS FARTHER
SOUTH AND EAST, THE SURFACE CYCLONE WILL DRIVE NORTH AND EAST
TOWARDS THE SOUTHERN OHIO VALLEY/WESTERN MID-ATLANTIC REGION. THOUGH
THE WARM FRONT OF THE SURFACE LOW, EXTENDING HORIZONTALLY EASTWARD,
WILL REMAIN WELL TO OUR SOUTH, WARM AIR ADVECTION AND ISENTROPIC
LIFT WILL INCREASE FROM SOUTH TO NORTH, INTERSECTING THE FAVORED
RIGHT ENTRANCE REGION OF THE UPPER JET TO ENHANCE VERTICAL ASCENT
ACROSS THE AREA. AT THIS TIME, THE SURFACE LOW LOOKS TO REMAIN SOUTH
OF THE REGION, RUNNING NORTH AND EAST ALONG LONG ISLAND SUCH THAT
COOLER AIR IS USHERS INTO THE REGION ON ITS NORTHWEST QUADRANT.
ADDITIONAL AID IN VERTICAL ASCENT WITH PVA ALONG THE LEADING
EDGE OF THE INCOMING SHORTWAVE WILL ALLOW WIDESPREAD
PRECIPITATION TO OVERSPREAD THE REGION BEGINNING EARLY TOMORROW
AFTERNOON AND LASTING THROUGH TOMORROW NIGHT AS FAST UPPER-LEVEL
FLOW BRINGS THE SWIFT EXIT OF BOTH THE UPPER SHORTWAVE AND THE
EVENTUAL COASTAL LOW.
WITH LATEST GUIDANCE KEEPING CONTINUITY WITH THE LOW TRACKING SOUTH
OF THE REGION, ISOTHERMAL PROFILES, AND THEREFORE A RAIN/SNOW,
SOLUTION IS FAVORED. UPSLOPE ENHANCEMENT THROUGH SOUTHWEST FLOW IN
THE HIGHER ELEVATIONS OF THE SOUTHWEST ADIRONDACKS, EASTERN
CATSKILLS, SOUTHERN GREENS, AND BERKSHIRES WILL PROMOTE ADDITIONAL
COOLING LEADING TO A PRIMARY PRECIPITATION TYPE OF SNOW.
ELSEWHERE IN VALLEY AREAS, RAIN WILL BE THE PRIMARY
PRECIPITATION TYPE, THOUGH SOME LIGHT, WET SNOW COULD MIX IN
ESPECIALLY TOMORROW NIGHT AS TEMPERATURES COOL. HOWEVER, THIS
WOULD PRIMARILY BE IN THE MOHAWK VALLEY AND UPPER-HUDSON WHERE
LATEST FORECAST SOUNDINGS SHOW BELOW OR FREEZING TEMPERATURES
JUST ABOVE THE SURFACE. GENERALLY, SNOWFALL ACCUMULATIONS ACROSS
THE REGION WILL REACH A DUSTING TO 2 INCHES WITH THE HIGHEST
ACCUMULATIONS IN THE SOUTHWEST ADIRONDACKS AND SOUTHERN GREEN
MOUNTAINS WHERE 3 TO LOCALIZED AMOUNTS OF UP TO 4 INCHES ARE
POSSIBLE. AT THIS TIME, MEDIUM CONFIDENCE EXISTS IN SNOW
ACCUMULATIONS REACHING UP TO 3 INCHES IN THESE AREAS WITH LOW
CONFIDENCE IN LOCALLY HIGHER AMOUNTS OF 4 INCHES. THE MAIN
DRIVER OF LOWER-END CONFIDENCE IN THESE LOCALLY HIGHER AMOUNTS
IS THE TIMING OF SNOWFALL. THIS WILL BE A FAIRLY PROGRESSIVE
SYSTEM, SO THE SHEAR DURATION OF SNOWFALL COULD SIGNIFICANTLY
LIMIT THE AMOUNT OF SNOWFALL RECEIVED EVEN WITH UPSLOPE FLOW TO
HELP WITH ADDITIONAL ACCUMULATIONS.
MUCH OF THE PRECIPITATION SHOULD BE SAID AND DONE BEFORE THE MORNING
COMMUTE THURSDAY, SO NO VISIBILITY ISSUES WILL BE HAD DURING ROUTINE
TRAVEL, THOUGH UNTREATED ROADWAYS COULD BE SLIPPERY. WEAK,
PERSISTENT CYCLONIC FLOW AND THE PASSAGE OF A BACK-DOOR COLD FRONT
COULD LEAD TO SOME LIGHT LAKE EFFECT SHOWERS OFF LAKE ONTARIO FOR
THE SOUTHWEST ADIRONDACKS THROUGH THURSDAY MORNING, BUT DRY
CONDITIONS WILL BE REINFORCED REGIONWIDE BY THE AFTERNOON AS HIGH
PRESSURE MOVES IN OVERHEAD FROM SOUTHERN ONTARIO. HIGH TEMPERATURES
THURSDAY WILL BE COOLER THAN WEDNESDAY WITH UPPER 20S TO UPPER 30S
AND POCKETS OF LOW 40S IN THE MID-HUDSON VALLEY. LOW TEMPERATURES
THURSDAY NIGHT WILL THEN DROP TO THE UPPER 10S TO MID 20S WITH LOW
10S IN THE SOUTHWEST ADIRONDACKS.
LONG TERM /FRIDAY THROUGH TUESDAY/
THE LONG TERM PERIOD WILL BE DRY IN COMPARISON TO RECENT DAYS WITH
TEMPERATURES GRADUALLY FALLING BELOW NORMAL FOR THE WEEKEND INTO
EARLY NEXT WEEK...
THE AFOREMENTIONED HIGH PRESSURE WILL SLIDE EASTWARD THROUGH
SOUTHEAST CANADA FRIDAY AS ANOTHER SHORTWAVE DISTURBANCE SINKS SOUTH
AND EAST FROM THE GREAT LAKES. A WEAK SURFACE WAVE WILL DEVELOP AND
SLIDE EAST THROUGH THE OHIO VALLEY INTO THE MID-ATLANTIC, ALLOWING
SCATTERED SNOW SHOWERS TO DEVELOP LATE FRIDAY MORNING/EARLY FRIDAY
AFTERNOON, HOWEVER THERE STILL REMAINS A GOOD AMOUNT OF UNCERTAINTY
IN SPATIAL COVERAGE. SHOWERS WILL CONTINUE THROUGH FRIDAY NIGHT AS
THE AFOREMENTIONED SHORTWAVE DEEPENS OVER THE REGION AND AN ARCTIC
COLD FRONT SWINGS THROUGH THE REGION. SNOW SHOWERS WILL TAPER OFF
THROUGH THE DAY SATURDAY WITH REGIONWIDE DRY CONDITIONS
RETURNING SATURDAY EVENING THROUGH THE REMAINDER OF THE LONG
TERM PERIOD WITH HIGH PRESSURE BECOMING LOCKED IN ACROSS EASTERN
CONUS. BEHIND THE ARCTIC COLD FRONT, MUCH COOLER, BELOW-NORMAL
TEMPERATURES WILL BE IN PLACE.
FRIDAY WILL BE THE WARMEST DAY OF THE PERIOD WITH HIGHS IN THE LOW
20S TO LOW 30S ACROSS THE REGION. SATURDAY WILL SEE HIGHS PRIMARILY
IN THE UPPER 10S TO UPPER 20S BEFORE SUNDAY'S HIGHS ONLY REACH
SINGLE DIGITS TO LOW 20S. A SLIGHT INCREASE IN HIGHS THEN COMES
MONDAY WITH UPPER 10S TO MID 20S. LOW TEMPERATURES FRIDAY WILL FALL
TO THE LOW 10S TO LOW 20S WITH SINGLE DIGITS IN THE SOUTHWEST
ADIRONDACKS. SATURDAY AND SUNDAY NIGHTS WILL BOTH FEATURE NEGATIVE
SINGLE DIGITS AT HIGH ELEVATIONS WITH LOW TO UPPER SINGLE DIGITS
ELSEWHERE. MONDAY NIGHT'S LOWS WILL FALL TO THE UPPER SINGLE DIGITS
TO LOW 10S.
AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
THROUGH 06Z THURSDAY...LOW-VFR CIGS AT 3-5 KFT WITH UNRESTRICTED
VSBYS ARE EXPECTED TO PREVAIL THROUGH THE OVERNIGHT PERIOD AT
ALB/GFL/PSF WHILE CLEAR SKIES ASIDE FROM PASSING HIGH CIRRUS AT POU
WILL ALLOW FOR PERIODS OF IFR VSBYS WITHIN FOG/MIST THROUGH SUNRISE.
VFR CONDITIONS OTHERWISE CONTINUE THROUGH 18-21Z WED WITH PERSISTENT
LOW CLOUD BASES AT 3-5 KFT AND INCREASING HIGHER CLOUDS AT 10-20
KFT. CALM TO LIGHT SOUTHWEST WINDS ARE EXPECTED AT ALL TERMINALS
BEFORE TURNING OUT OF THE SOUTH AT 3-6 KT AFTER 12-16Z WED.
A COLD FRONT APPROACHING THE REGION FROM THE WEST WILL SEE RAIN AND
SNOW SHOWERS SPREAD EASTWARD THROUGH THE AFTERNOON, 20-24Z WED.
FLYING CONDITIONS WILL RAPIDLY DETERIORATE TO MVFR AND ULTIMATELY
IFR/LIFR AS CIGS FALL TO 1-1.5 KFT OR LESS AND VSBYS TO 2SM TO LESS.
VSBYS MAY FALL BELOW 1SM WHERE SNOW BECOMES THE DOMINANT P-TYPE,
MOST LIKELY AT GFL/PSF. ALB/POU WILL MORE LIKELY SEE MORE RAIN AND
MAINTAIN HIGHER, BUT STILL IFR OR LOW-MVFR, VSBYS. CALM TO LIGHT AND
VARIABLE WINDS ARE EXPECTED DURING STEADY PRECIPITATION.
OUTLOOK...
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHSN.
SATURDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
ALY WATCHES/WARNINGS/ADVISORIES
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...GANT
LONG TERM...GANT
AVIATION...PICARD
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