046
FXUS61 KALY 201042
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
642 AM EDT WED AUG 20 2025
SYNOPSIS
A LOW PRESSURE SYSTEM AND UPPER LEVEL DISTURBANCE BRING
BENEFICIAL RAIN TO THE REGION THROUGH TODAY BEFORE THE END OF
THE WEEK AND INTO THE FIRST HALF OF THE WEEKEND SEES THE RETURN
OF DRY WEATHER. ADDITIONAL CHANCES FOR SHOWERS AND SOME
THUNDERSTORMS COME SUNDAY INTO THE BEGINNING OF NEXT WEEK AS AN
UNSETTLED PATTERN TAKES HOLD OF THE REGION. TEMPERATURES REMAIN
COOL BY LATE AUGUST STANDARDS FOR MUCH OF THE NEXT SEVEN DAYS,
THOUGH VALUES WILL WARM CLOSER TO NORMAL FOR FRIDAY AND
SATURDAY.
DISCUSSION
A POSITIVELY-TILTED, MID-LEVEL SHORTWAVE, WHOSE AXIS EXTENDS
SOUTH AND WEST FROM SOUTHEAST ONTARIO THROUGH THE EASTERN GREAT
LAKES INTO THE OHIO VALLEY, ENCROACHES FROM THE WEST ALMOST
DIRECTLY ATOP A SURFACE CYCLONE ALSO SPANNING THE EASTERN GREAT
LAKES AND OHIO VALLEY REGIONS. INCREASED LOW-LEVEL CONVERGENCE
RESULTING FROM THE INVERTED TROUGH NOSING INTO THE REGION ABOUT
THE LOW INTERSECTS THE DIVERGENT REGION OF THE UPPER
TROUGH, ALLOWING AN INITIAL BATCH OF RAIN TO MOVE THROUGH THE
REGION EARLY THIS MORNING.
ADDITIONAL ROUNDS OF RAIN WILL ACCOMPANY THE DEEPENING OF THE
TROUGH ALOFT AND THE SOUTHEASTWARD SLIDE OF THE SURFACE LOW
TODAY AS LOW TO MID-LEVEL FRONTOGENETICAL FORCING INCREASES
COURTESY OF THE STEEPENING TEMPERATURE GRADIENT FORCED BY WINDS
BACKING FROM THE SOUTHEAST TO THE EAST (AND EVENTUALLY
NORTHEAST). LATEST CAMS STILL SEEM TO BE STRUGGLING A BIT WITH A
CONSENSUS AS TO THE SPATIAL EXTENT OF RAIN THROUGHOUT THE DAY,
LIKELY DUE TO THEIR DIFFERENCES IN THE RESOLUTION OF LOW- LEVEL
DRY AIR AND MESOSCALE DRYING AFFECTS FROM DOWNSLOPE WINDS.
ADDITIONALLY, THE TRACK OF THE SURFACE LOW HAS SHIFTED SLIGHTLY
FARTHER SOUTH WITH AN ADJACENT ANTICYCLONE REMAINING JUST OFF TO
OUR NORTH AND EAST. THEREFORE, THE HEAVIEST QPF HAS BEEN
LOWERED SLIGHTLY, COMPRESSED, AND SHUNTED JUST A BIT FARTHER
SOUTH THAN PREVIOUS FORECASTS. STILL, ENHANCED FGEN, UPSLOPE
FLOW, AND ENHANCED LOW LEVEL CONVERGENCE WILL LEAD TO AN AXIS OF
MORE MODERATE RAINFALL MAINLY IN THE SOUTHWESTERN MOHAWK
VALLEY, NORTHEAST CATSKILLS, AND HELDERBERGS. STORM TOTAL
AMOUNTS ARE PROGGED TO REACH NEAR 0.5" TO 1.5" WITH LOCALLY
HIGHER AMOUNTS IN THE AFOREMENTIONED AREAS OF 1.65" AND LOCALLY
LOWER AMOUNTS IN PORTIONS OF THE SOUTHWEST ADIRONDACKS, LOWER
MID-HUDSON VALLEY/NORTHWEST CONNECTICUT, AND UPPER-HUDSON VALLEY
OF ~0.25" TO 0.4". HIGHS TODAY WILL BE MUCH COOLER THAN TYPICAL
LATE-AUGUST STANDARDS WITH MID/UPPER 50S TO LOW/MID 60S
ANTICIPATED.
RAIN BEGINS TO DWINDLE THIS EVENING, BECOMING MERE LIGHT, SCATTERED
SHOWERS BY TONIGHT BEFORE CEASING EARLY THURSDAY MORNING. LOWS
TONIGHT WILL FALL TO THE UPPER 40S TO MID/UPPER 50S. THE
AFOREMENTIONED SHORTWAVE TROUGH WILL CONTINUE ITS SOUTHEASTWARD
DEPARTURE THROUGH THE DAY THURSDAY, INTERSECTING HURRICANE ERIN
JUST IN TIME TO HELP KICK IT OUT TO SEA AND AWAY FROM THE NEW
ENGLAND COAST. LOCALLY, SURFACE HIGH PRESSURE WILL BEGIN TO
ENCROACH FROM THE NORTHWEST WITH AMPLIFYING HEIGHTS ALOFT
REINFORCING DRY CONDITIONS. TEMPERATURES WILL CONSEQUENTLY BEGIN
TO WARM, RISING INTO THE MID/UPPER 60S TO LOW/MID 70S THURSDAY
AND INTO THE MID/UPPER 70S TO LOW/MID 80S BY SATURDAY AS THE
RIDGE ALOFT CRESTS OVER THE NORTHEAST. LOW TEMPERATURES FRIDAY
NIGHT WILL BE LARGELY IN THE 50S WITH MID 50S TO LOW 60S
EXPECTED ON SATURDAY NIGHT.
TRANQUILITY COMES TO AN END SUNDAY INTO THE BEGINNING OF NEXT
WEEK AS AN UNSETTLED PATTERN SETS IN. SATURDAY'S RIDGE WILL BE
FORCED TO THE EAST AS A LARGE-SCALE TROUGH DIGS SOUTH INTO THE
MIDWEST ABOUT THE SOUTHERN PERIPHERY OF A CLOSED LOW SITUATED IN
CENTRAL ONTARIO. AHEAD OF THE ATTENDANT COLD FRONT, SHOWERS AND
POTENTIAL THUNDERSTORMS LOOK TO SPREAD INTO THE REGION WHILST A
FAIRLY POTENT SHORTWAVE AND ASSOCIATED VORT MAX ROTATE ABOUT THE
MEAN FLOW OF THE TROUGH, POTENTIALLY FORCING ITS SLIGHT NEGATIVE
TILT BY MONDAY AFTERNOON/EVENING. ADDITIONAL ROUNDS OF SHOWERS
AND POSSIBLE THUNDERSTORMS WOULD LINGER INTO TUESDAY AS
ADDITIONAL SHORTWAVES PULSE THROUGH THE PRIMARY UPPER TROUGH,
BUT EXACT COVERAGE AND SEVERITY OF ANY SHOWERS AND THUNDERSTORMS
SUNDAY THROUGH TUESDAY IS UNCERTAIN AT THIS TIME. TIMING WILL
PLAY A BIG ROLE IN DETERMINING THESE ELEMENTS OF THE FORECAST.
SO, FOR NOW WE HAVE MAINTAINED THE NBM POPS WHICH KEEP MOST OF
THE PRECIPITATION CONFINED TO SUNDAY AND MONDAY. TEMPERATURES
DURING THIS TIME WILL ONCE AGAIN FALL COOLER THAN LATE-AUGUST
STANDARDS WITH UPPER 60S TO LOW 80S SUNDAY FALLING TO 60S TO
LOW/MID 70S BY TUESDAY. LOWS SUNDAY NIGHT WILL REMAIN ON THE
MILDER SIDE WITH VALUES IN THE MID 50S TO LOW 60S, BUT MONDAY
NIGHT AND TUESDAY NIGHT WILL SEE VALUES IN THE 40S AND 50S.
AVIATION /12Z WEDNESDAY THROUGH SUNDAY/
OVERALL THINKING FOR THE AVIATION FORECAST REMAINS ON TRACK WITH
MVFR/IFR CONDITIONS PREVAILING THROUGHOUT THE DAY WITH
WIDESPREAD SHRA. CONFIDENCE HAS INCREASED IN PERIODS OF IFR
VISIBILITY RESTRICTIONS AT KALB AND KPSF WHERE TEMPO GROUPS WERE
ADDED WITH THIS FORECAST CYCLE. MORE WIDESPREAD IFR CEILINGS
ARE FORECAST TO DEVELOP ACROSS THE REGION AFTER 03Z THIS EVENING.
SOUTHEAST TO EAST WINDS DURING THE MORNING HOURS ARE FORECAST
TO SHIFT TO NORTHEAST LATE THIS AFTERNOON INTO THIS EVENING.
OUTLOOK...
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SUNDAY: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
SUNDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
MONDAY: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
ALY WATCHES/WARNINGS/ADVISORIES
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
SYNOPSIS...GANT
DISCUSSION...GANT
AVIATION...TH
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