941
FXUS61 KALY 201742
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
142 PM EDT FRI MAR 20 2026
WHAT HAS CHANGED
REDUCED THE SNOWFALL AMOUNTS ACROSS THE ADIRONDACKS FOR THE
INCOMING SYSTEM THIS AFTERNOON INTO TONIGHT AS THE WINDOW OF
OPPORTUNITY FOR SNOW HAS BECOME SMALLER. OTHERWISE, THE FORECAST
GENERALLY REMAINS ON TRACK WITH ONLY MINOR ADDITIONAL
ADJUSTMENTS.
KEY MESSAGES
1) TWO CLIPPER SYSTEMS WILL TRACK THROUGH THE REGION THROUGH THE
END OF THIS WEEK AND INTO THE BEGINNING OF NEXT, BRINGING A MIX
OF RAIN AND SNOW IN ADDITION TO LOW PROBABILITIES OF SIGNIFICANT
IMPACTS.
DISCUSSION
KEY MESSAGE 1...
AN ANOMALOUS, SOUTHERN STREAM, UPPER-LEVEL ANTICYCLONE CONTINUES
TO DOMINATE THE DEEP SOUTHWEST, EXTENDING A LARGE-SCALE RIDGE
NORTHWARD THAT ENCOMPASSES NEARLY HALF THE CONUS. MEANWHILE,
NORTHERN STREAM NORTHWEST FLOW HAS KEPT THE GREAT LAKES AND
NORTHEAST UNDER THE INFLUENCE OF TROUGH-RESEMBLING REGIME THAT
WILL CONTINUE THROUGH MUCH OF THE REMAINDER OF THE WEEK.
ULTIMATELY, THIS WILL ALLOW MULTIPLE CLIPPER SYSTEMS TO TRACK
THROUGH THE REGION, BRINGING PERIODS OF RAIN, SNOW, AND A MIX
THEREOF INTO EARLY NEXT WEEK. THE FIRST OF THESE CLIPPERS IS
ANTICIPATED TODAY THROUGH TONIGHT.
A PROGRESSIVE SURFACE LOW WILL RIDE ATOP THE WESTERN RIDGE AND
EJECT SOUTHEASTWARD OUT OF THE UPPER MIDWEST TOWARDS THE GREAT
LAKES THROUGH THIS MORNING. ALOFT, A ONCE WEAK ASSOCIATED
SHORTWAVE EMBEDDED WITHIN THE UPPER-LEVEL NORTHWESTERLY FLOW
WILL DEEPEN, TRIGGERING A SLIGHT INTENSIFICATION OF THE SURFACE
CYCLONE. BY MID- TO LATE-MORNING, THE LOW WILL HAVE REACHED THE
EASTERN GREAT LAKES, EXTENDING A HORIZONTAL WARM/PSEUDO-
STATIONARY FRONT EASTWARD JUST NORTH OF OR JUST ALONG THE
NORTHERN FRINGE OF OUR SOUTHERN ADIRONDACK ZONES. A STRATIFORM
PRECIPITATION SHIELD ASSOCIATED WITH THE AXIS OF INCREASING WARM
AIR ADVECTION AND ISENTROPIC LIFT WILL THEN BEGIN TO MOVE INTO
THE REGION AND EXPAND SOUTHEASTWARD THROUGH THE REMAINING HOURS
OF THE MORNING AND PRELIMINARY HOURS OF THE AFTERNOON.
INITIALLY, SUFFICIENT CLOUD COVER SHOULD HOLD TEMPERATURES ON
THE COOLER SIDE ACROSS THE ADIRONDACKS SUCH THAT PRECIPITATION
BEGINS AS SNOW. FURTHER PROVIDING CONFIDENCE IN THIS ELEMENT OF
THE FORECAST IS THE COMBINATION OF LOW LEVEL DRY AIR THAT WILL
ENHANCE THE EFFECTS OF WETBULB COOLING WHERE TEMPERATURES MAY
JUST BE OVER FREEZING AT ONSET, AN 850MB FGEN BAND ENHANCING
VERTICAL ASCENT THEREBY PROVIDING RAPID COOLING, AND THE
ANTICIPATION OF EFFICIENT FLAKE PRODUCTION WITHIN THE DENDRITIC
GROWTH ZONE WHERE STRONG OMEGA EXISTS. FOR THESE REASONS, A
QUICK HALF TO INCH AND A HALF OF SNOW COULD ACCUMULATE ACROSS
THE HIGHEST ELEVATIONS OF THE SOUTHERN ADIRONDACKS WITHIN A
COUPLE HOURS OF PRECIPITATION ONSET. IN FACT, WE MENTIONED
MODERATE SNOWFALL IN THE FORECAST FOR A FEW HOURS EARLY THIS
AFTERNOON AS THE AFOREMENTIONED STRONG FORCING COULD LEAD TO
SOME DECENT RATES (0.5-1"/HR PER THE LATEST HREF) FOR A SHORT
PERIOD OF TIME. HOWEVER, PERSISTENTLY INCREASING WARM AIR
ADVECTION WILL QUICKLY FORCE THE TRANSITION TO A RAIN/SNOW MIX
BEFORE PLAIN RAIN BECOMES THE DOMINANT PRECIPITATION TYPE.
ALL AREAS OUTSIDE THE SOUTHERN ADIRONDACKS, ASIDE FROM ISOLATED
HIGH PEAKS OF THE SOUTHERN GREENS, WILL SEE PLAIN RAIN
THROUGHOUT THE DURATION OF THIS EVENT WITH RATES BECOMING
MODERATE TO LOCALLY HEAVY AT TIMES. THE SOUTHEAST SPREAD OF THE
STRATIFORM PRECIPITATION SHIELD WILL INTERSECT A SOUTHWESTERLY, 40-50KT
850MB LLJ THIS AFTERNOON THAT WILL PROMOTE EFFICIENT MOISTURE
TRANSPORT INTO THE STILL STRONGLY FORCED ENVIRONMENT. THEREFORE,
WE ALSO MENTIONED MODERATE RAINFALL FOR SEVERAL HOURS THIS
AFTERNOON, PARTICULARLY FOR PORTIONS OF THE MOHAWK VALLEY,
UPPER-HUDSON VALLEY, EASTERN CATSKILLS, AND SOUTHERN GREENS
WHERE UPSLOPE FLOW WILL ALSO PROVIDE ADDITIONAL FORCING FOR
EFFICIENT RAINFALL PRODUCTION. NOW, WE DID MENTION SOME MODERATE
RAINFALL ACROSS PORTIONS OF THE CAPITAL REGION, MID-HUDSON
VALLEY, AND SOUTHWEST NEW ENGLAND AS WELL DUE TO THE POTENTIAL
FOR EMBEDDED DOWNPOURS AS THE LOW TRAVERSES OVERHEAD JUST BEFORE
ITS ASSOCIATED COLD FRONT. HOWEVER, LATEST HIRES GUIDANCE IS
INDICATING THAT THERE COULD BE SOME DOWNSLOPING AND SHADOWING
THAT OCCURS OFF THE CATSKILLS THAT COULD LIMIT THE AMOUNT OF
RAIN THAT FALLS IN THESE AREAS.
PRECIPITATION ASSOCIATED WITH THIS FIRST SYSTEM CONCLUDES
TONIGHT AS IT SWIFTLY DEPARTS THROUGH THE REGION TO THE EAST. BY
EARLY TOMORROW MORNING, DRY CONDITIONS WILL BE REINFORCED
ACROSS THE REGION AS DRIER AIR FILTERS IN BENEATH A COUPLE OF
NEARBY SURFACE HIGHS NUDGING EAST AND SOUTHWARD. SATURDAY WILL
THEREFORE BE DRY AHEAD OF THE NEXT CLIPPER THAT WILL INCREASE
THE PROBABILITY OF PRECIPITATION ONCE AGAIN BEGINNING SATURDAY
NIGHT. THE FORECAST FOR THIS NEXT SYSTEM CONTINUES TO CONTAIN
ITS FAIR SHARE OF UNCERTAINTY, THOUGH CONFIDENCE IS BEGINNING TO
INCREASE BASED ON LATEST TRENDS IN THE GUIDANCE.
SIMILARLY TO THE PREVIOUS SYSTEM, ANOTHER SURFACE LOW WILL MOVE
INTO THE GREAT LAKES BY SATURDAY NIGHT, TRACKING ORIGINALLY FROM
THE UPPER-MIDWEST. DISSIMILARLY, THIS IS ACTUALLY ONE OF SEVERAL
LOW CENTERS SPANNING A BROAD SWATH OF SURFACE LOW PRESSURE THAT
EXTENDS SOUTH AND WEST AS FAR AS THE TEXAS PANHANDLE ALONG AN
ELONGATED COLD FRONT. BY THE TIME THE LOW ADJACENT TO OUR AREA
MOVES INTO THE GREAT LAKES, UPPER-LEVEL FLOW WILL HAVE BECOME
QUASI- ZONAL AND FAIRLY COMPACT WITH NUMEROUS EMBEDDED
SHORTWAVES UPSTREAM AND THE FURTHER DEEPENED SHORTWAVE OF THE
PREVIOUS SYSTEM JUST DOWNSTREAM OVER ATLANTIC CANADA. THIS WILL
CREATE A FAIRLY COMPACT BAROCLINIC ZONE ACROSS OUR AREA THAT, AT
THIS POINT, LOOKS TO SUPPORT COOLER TEMPERATURES AND
SUBSEQUENTLY AN INITIAL ONSET TYPE OF SNOW ALMOST EVERYWHERE SATURDAY
NIGHT. THAT SAID, IF THE AREA OF LOW PRESSURE SHIFTS A BIT
FARTHER NORTH, MORE OF A RAIN/SNOW MIX OR PLAIN RAIN WOULD BE
THE SOLUTION FOR AREAS OUTSIDE OF THE ADIRONDACKS. A FARTHER
SOUTH TRACK OF THE LOW WOULD MEAN A MORE PROLONGED PERIOD OF
SNOW ACROSS MORE OF THE REGION. THE CURRENT FORECAST ERRS ON THE
SIDE OF THE LATEST TRENDS OF THE LOW TRACKING FARTHER SOUTH, BUT
THAT IS A BIT DIFFERENT THAN PREVIOUS DAYS. WHAT'S IMPORTANT TO
NOTE HERE, THOUGH, IS THAT AS WARM AIR ADVECTION INCREASES WITH
THIS SYSTEM AND DIURNAL MODERATION OCCURS THROUGHOUT THE DAY
SUNDAY, SNOW WILL ULTIMATELY TRANSITION TO A RAIN/SNOW MIX AND
PLAIN RAIN UNTIL SNOW RETURNS AGAIN OVERNIGHT SUNDAY. WE DON'T
ANTICIPATE, AT LEAST AT THIS TIME, ANY FREEZING RAIN OR SLEET
WITH THIS SYSTEM. BUT THE UNCERTAINTY PERTAINING TO THE POSITION
OF THE LOW AND THE RESULTING DURATION AND SPATIAL SPREAD OF SNOW
POSES UNCERTAINTY IN THE RESULTING ACCUMULATIONS. WE WILL
CONTINUE TO MONITOR OVER THE COMING DAYS AND PROVIDE
UPDATES/ISSUE ANY HEADLINES SHOULD THEY BE NEEDED.
PRECIPITATION FROM THIS SYSTEM COULD LINGER INTO MONDAY NIGHT,
BUT BY TUESDAY, HIGH PRESSURE LOOKS TO BUILD IN TO FORCE THE
RETURN OF REGIONWIDE DRY CONDITIONS. LOOKING AHEAD FURTHER INTO
NEXT WEEK, ADDITIONAL OPPORTUNITIES FOR PRECIPITATION ALTERNATE
WITH DRY PERIODS AS IN TYPICAL MARCH FASHION. BUT NO SIGNIFICANT
IMPACTS ARE ANTICIPATED AT THIS TIME.
AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
THROUGH 18Z/SAT...A FRONTAL SYSTEM WILL CROSS THE REGION THIS
AFTERNOON INTO TONIGHT. PERIODS OF MVFR/IFR (MAINLY FOR VSBYS)
ARE EXPECTED AS THE RAIN TRACKS THROUGH THIS AFTERNOON INTO THE
EVENING, ESPECIALLY WITHIN ANY POCKETS OF MODERATE RAIN. THE
RAIN SHOULD TAPER OFF FROM NW TO SE BETWEEN 23Z/FRI-04Z/SAT,
HOWEVER LINGERING LOW CLOUDS AND MIST/DRIZZLE SHOULD KEEP FLIGHT
CONDITIONS MVFR/IFR INTO THE OVERNIGHT HOURS BEFORE LIFTING
BACK TO VFR BY SATURDAY MORNING (LAST AT KPSF).
WIND WILL REMAIN SOUTHERLY AT 8-15 KT THIS AFTERNOON BEFORE
TRENDING VARIABLE AT 5 KT OR LESS THIS EVENING. WIND WILL SHIFT
TO THE NORTHWEST AT AROUND 10 KT BETWEEN 6-12Z/SAT, EXCEPT
NORTHERLY AT KGFL. PERIODS OF LLWS IS EXPECTED MAINLY AT KPSF
UNTIL 00Z/SAT WITH 2000 FT WINDS INCREASING TO 35 TO 45 KT.
OUTLOOK...
SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
SUNDAY: HIGH OPERATIONAL IMPACT. DEFINITE RA...SN.
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN.
MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SN.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. BREEZY. CHANCE OF RA...SN.
ALY WATCHES/WARNINGS/ADVISORIES
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
DISCUSSION...12
AVIATION...33
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