An area of low pressure moved northward from the mid-Atlantic region passing over Cape Cod Monday evening, August 15th. This low brought heavy rains to east central New York with enhanced amounts across the higher terrain of the eastern Catskills.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS ALY wrote it up.
An area of low pressure moved northward from the mid-Atlantic region passing over Cape Cod Monday evening, August 15th. This low brought heavy rains to east central New York with enhanced amounts across the higher terrain of the eastern Catskills. Rainfall amounts across Ulster County ranged from about 2 to 6 inches.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Albany, NY wrote its last area forecast discussion before the first event at Aug 15, 5:55 AM EST, 2 hours 30 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
655 AM EDT MON AUG 15 2011
.SYNOPSIS...
LOW PRESSURE OVER THE DELMARVA PENINSULA AND ITS ASSOCIATED FRONTAL
BOUNDARIES WILL VERY SLOWLY MOVE EAST TODAY AND BRING A SOAKING
RAIN TO MOST OF THE REGION. A RESIDUAL UPPER LEVEL DISTURBANCE ON
TUESDAY WILL KEEP THE THREAT OF ADDITIONAL SCATTERED SHOWERS AROUND.
THEN...HIGH PRESSURE WILL BUILD IN FOR WEDNESDAY BRINGING A DRY
SEASONABLY WARM DAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FLOOD WATCH CONTINUES FOR THE HUDSON RIVER VALLEY EASTWARD AND
FOR THE ADJACENT WESTERN NEW ENGLAND THROUGH TODAY...
AS OF 645 AM...WE HAD TO ISSUE A FLOOD ADVISORY FOR MUCH OF THE
HUDSON VALLEY FROM SOUTH OF ALBANY...TO NORTH OF SARATOGA SPRINGS.
RIGHT NOW...THIS IS THE AREA GETTING THE HEAVIEST RAINFALL...WITH
DOPPLER ESTIMATED AMOUNTS OVER HALF AN INCH AN HOUR. HOWEVER...THIS
AREA OF HEAVY RAIN WAS OVERALL SHRINKING IN AREA.
VERY HEAVY RAINFALL FELL ACROSS OTHER PORTIONS OF OUR AREA...WITH
WEST SHOKAN IN ULSTER COUNTY REPORTING 3.49 INCHES THUS FAR AND
PLYMOUTH IN LITCHFIELD COUNTY OVER 4 INCHES! PLEASE REFER TO OUR
PUBLIC INFORMATION STATEMENT FOR ALL THE LATEST RAINFALL AMOUNTS.
AS FAR AS WE CAN SURMISE...THESE VALUES ARE THE EXCEPTION RATHER
THAN THE RULE.
UPSTREAM...LESSER RAIN NOW FALLING ACROSS SOUTHERN NEW YORK. A VERY
IMPRESSIVE BAND ON RADAR...THE WARM CONVEYOR BELT OFF THE LONG
ISLAND SOUND SHOULD STAY WELL TO OUR EAST.
WE WILL KEEP THE FLOOD WATCH GOING. (BTW...THE THE FLOOD ADVISORY
GOES UNTIL 830 AM). ONLY VERY MINOR TWEAKS OF TEMPERATURES AND OTHER
GRIDS BUT THE OVERALL FORECAST IN TACT.
*******PREVIOUS NEAR TERM FORECAST************
AS OF 430 AM...RAIN CONTINUES ACROSS THE REGION...BUT SO FAR...TOTAL
RAINFALL AMOUNTS NOT ALL THAT IMPRESSIVE. KENX RADAR DOES SHOW CLOSE
TO AN INCH ACROSS PORTIONS OF ULSTER...SOUTHERN DUTCHESS AND
SOUTHEAST LITCHFIELD COUNTIES. HOWEVER...MOST OTHER AREAS WELL UNDER
AN INCH...AND IN SOME CASES...EVEN BELOW HALF AN INCH. THESE
ESTIMATED APPEAR TO BE PRETTY GOOD COMPARED TO GROUND TRUTH
REPORTS.
CURRENT RAINFALL RATES GENERALLY UNDER UNDER A TENTH OF AN INCH MOST
AREAS.
NEVERTHELESS...WITH PWAT VALUES AROUND 1.75 INCHES ACROSS THE
REGION...LARGE SCALE ASCENT CONTINUING...AND SOME ELEMENTS OF
HEAVIER CONVECTIVE RAINFALL TRYING TO EVOLVE INTO A SECONDARY WARM
CONVEYOR BELT TO OUR SOUTH...WE WILL KEEP THE FLOOD WATCH IN PLACE.
IN A FEW HOURS...BY MORNING...THE EVIDENCE SHOULD BE CLEARER TO MAKE
A DECISION BY THEN.
OR WILL IT? THE 06Z NAM CAME WITH LESS QPF TODAY THAN PREVIOUS RUNS.
HOWEVER...THIS MODEL NOW INDICATES THAT POCKETS OF HEAVY RAIN WOULD
LAST WELL INTO THE NIGHT. NOT READY TO TAKE THE BAIT ON THIS
YET...BUT WITH CONSIDERABLE QPF UNCERTAINTIES...FEEL COMPELLED TO
KEEP THE WATCH IN PLACE.
LATER TODAY...WITH SOME HEATING IN THE LOW LEVELS...AND SLIGHT
COOLING ALOFT...THERE MIGHT BE SOME EMBEDDED THUNDERSTORMS WHICH
COULD ENHANCE LOCALLY HEAVY RAINFALL.
WITH CLOUDS AND RAINFALL...TEMPERATURES LOOK TO REMAIN NEARLY FLAT
LINED TODAY...ONLY TOPPING IN THE 65-70 RANGE...EXCEPT 70-75 IN THE
HUDSON VALLEY SOUTH OF ALBANY AS WELL AS LOWER LITCHFIELD. GENERALLY
WITH A MET/MAV BLEND FOR HIGHS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
DESPITE THE 06Z NAM...THE THINKING IS THE RAIN WILL TAPER TO
SCATTERED SHOWERS LATER TONIGHT AS THE STORM BEGINS TO PULL FURTHER
EAST. HOWEVER... THE UPPER AIR LOW WILL NEED TO MOVE THROUGH TONIGHT
INTO EARLY TUESDAY.
CERTAINLY CAN NOT RULE OUT LINGERING SHOWERS ON TUESDAY AS THE
SYSTEM IS SLOW TO EXIT...AND THERE WILL BE RESIDUAL MOISTURE AND
WEAKNESS ALOFT. THERE WILL BE MODEST SBCAPE...PROBABLY UNDER A 1000
J/KG EVERYWHERE BUT STILL COULD BE ENOUGH FOR A RUMBLE OR TWO OF
THUNDER...ESPECIALLY IF WE GET SOME GOOD BREAKS OF SUNSHINE BY
AFTERNOON.
TUESDAY NIGHT...THE SKY LOOKS TO CLEAR. WITH LIGHT WIND AND
SATURATED GROUND...SOME PATCHY VALLEY FOG LOOKS TO BE A GOOD BET.
HIGH PRESSURE FROM THE OHIO VALLEY WILL BRING A BEAUTIFUL DAY
WEDNESDAY FILLED WITH A GOOD OF SUNSHINE (OCCASIONALLY BLOTTED BY
FAIR WEATHER CU)...SEASONABLE TEMPERATURES AND COMFORTABLE
HUMIDITY.
TEMPERATURES LOOK TO DROP TO AROUND 60 IN THE HUDSON VALLEY
TONIGHT...555 TO 60 ELSEWHERE. THEY WILL REBOUND TO SEASONABLE
LEVELS ON TUESDAY...80 TO 85 VALLEYS AREAS....75-80 HIGHER TERRAIN.
SIMILAR OVERNIGHT LOWS TUESDAY NIGHT...PERHAPS A COUPLE DEGREES
COOLER. TEMPERATURES ON WEDNESDAY LOOK TO BE 80-85 VALLEY
AREAS....70S HIGHER TERRAIN.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WEAK HIGH PRESSURE BUILDS OFFSHORE WEDNESDAY NIGHT WITH INCREASING
CLOUDS THROUGH THE NIGHT AS NEXT FRONTAL SYSTEM APPROACHES FROM THE
GREAT LAKES REGION. TIMING AND TRACK OF THE NEXT SYSTEM STILL QUITE
UNCERTAIN...BUT THE GENERAL TIME WINDOW OF THE BEST CHANCES OF
SHOWERS AND THUNDERSTORMS LOOKS TO BE THURSDAY AFTERNOON THROUGH
FRIDAY. QUESTION IS HOW MUCH OF THE EVOLVING EAST COAST TROUGH
AMPLIFIES TO KEEP THE CHANCE FOR PRECIP IN THE FORECAST LONGER?
LATEST ENSEMBLE...NCEP MODEL SUITE AN INTERNATIONAL GUIDANCE WANT TO
AMPLIFY THIS TROUGH OVER THE DELMARVA REGION TOWARD THE END OF THE
WEEK AND PERHAPS INTO THE START OF THE WEEKEND WITH MORE SHOWERS AND
THUNDERSTORMS TO THE REGION. THEREAFTER...VERY LOW CONFIDENCE AS
THE ECMWF IS MORE AMPLIFIED ALOFT AS COMPARED THE GFS AND ASSOCIATED
ENSEMBLES. SO WE WILL PLACE JUST BELOW SLIGHT CHANCE POPS AT THE
PRESENT TIME WITH MORE CLARIFICATION EXPECTED IN FUTURE MODEL RUNS.
THIS IS IN AGREEMENT WITH PREVIOUS FORECASTS AND HPC GUIDANCE.
TEMPERATURES THROUGH THE LONG TERM WILL AVERAGE NEAR TO SLIGHTLY
BELOW NORMAL FOR DAYTIME HIGHS AND NEAR NORMAL FOR OVERNIGHT LOWS.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
LOW END MVFR INTO IFR CONDITIONS THE REMAINDER OF THIS MONDAY EARLY
MORNING. MAIN BATCH OF RAIN WAS LIFTING NORTH ACROSS THE REGION
WITH SOME CONVECTIVE ENHANCEMENTS NOTED NEAR KPOU. THIS WILL KEEP
CIGS RATHER LOW AND WITHIN HEAVIER BURSTS OF PRECIP...THE VIS WILL
DROP BACK TO LESS THAN 3 MILES.
AVIATION CONDITIONS DO NOT IMPROVE TOO MUCH DURING THE DAYLIGHT
HOURS AS THIS UPPER LOW REMAINS NEARBY AND OCCASIONAL SHOWERS WITH
EMBEDDED THUNDERSTORMS /TO BE ACCOUNTED FOR WITH THE 'CB' GROUP/.
LIGHT AND VARIABLE WITH A TREND TOWARD A NORTH OR NORTHEAST WINDS
THE NEXT 24 HOURS.
OUTLOOK...
MON NT...MVFR-IFR. SHOWERS LIKELY IN THE EVENING...THEN CHC
SHOWERS.
TUE...MAINLY VFR. CHC -SHRA.
WED-THU...VFR. NO SIG WX.
FRI...VFR-MVFR...CHC -SHRA/-TSRA.
&&
.HYDROLOGY...
FLOOD WATCH ISSUED FOR THE HUDSON RIVER VALLEY EASTWARD AND FOR
THE ADJACENT WESTERN NEW ENGLAND THROUGH MONDAY...
IT NOW LOOKS AS IF THE HEAVIEST QPF WITH THIS SYSTEM...WILL BE FROM
THE HUDSON VALLEY EASTWARD...RIGHT ON TRACK WITH THE LOCATION OF THE
FLOOD WATCH. HOWEVER...THE BIGGER QUESTION IS WHETHER OR NOT
RAINFALL WILL ACTUALLY RESULT IN ANY FLOODING.
WE STILL THINK THE MOST LIKELY RAINFALL IN THE WATCH AREA WILL BE
1-3 INCHES...WHICH IF IT VERIFIES PERFECTLY WOULD NOT RESULT IN ANY
MAIN STEM RIVER FLOODING.
HOWEVER...THERE IS BATCH OF VERY RAINFALL OFF THE JERSEY SHORE
INCLUDING CONVECTION (THUNDERSTORMS). THIS IS PART OF THE WARM
CONVEYOR BELT PORTION OF THE SYSTEM...AND IT SHOULD REMAIN OFFSHORE.
HOWEVER...THERE ARE MORE CONVECTIVE ELEMENTS TRYING TO FILL IN
FURTHER SW ACROSS NEW JERSEY AND EVEN NE PA THAT MIGHT SIGNAL A NEW
CONVEYOR BELT TRYING TO BECOME ESTABLISHED. SUCH A WARM CONVEYOR
BELT COULD PRODUCE AN ADDITIONAL COUPLE INCHES OF RAINFALL...SO THE
TOTAL COULD EXCEED 4 INCHES...AND THAT WOULD BE ENOUGH TO INDUCE
SOME SORT OF FLOODING.
THE BOTTOM LINE...CONFIDENCE IS NOT THERE YET TO REMOVE THE FLOOD
WATCH SO WE WILL KEEP IT IN PLACE.
THIS SYSTEM WILL MOVE EAST TONIGHT. HOWEVER...THE 06Z NAM INDICATES
HEAVY RAINFALL IN MANY PLACES EVEN TONIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.FIRE WEATHER...
WET FLAG CONDITIONS TODAY WITH RAIN...POSSIBLY HEAVY AT
TIMES...ESPECIALLY FROM THE HUDSON VALLEY EASTWARD. WE EXPECT MOST
IF NOT ALL PLACES TO RECEIVE A QUARTER INCH OF RAIN TODAY.
RESIDUAL SHOWERS LOOK TO PERSIST TONIGHT...BECOMING SCATTERED ON
TUESDAY.
DRY WEATHER RETURNS IN EARNEST ON WEDNESDAY.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH THROUGH THIS EVENING FOR CTZ001-013.
NY...FLOOD WATCH THROUGH THIS EVENING FOR NYZ041>043-047>054-
058>061-063>066-083-084.
MA...FLOOD WATCH THROUGH THIS EVENING FOR MAZ001-025.
VT...FLOOD WATCH THROUGH THIS EVENING FOR VTZ013>015.
&&
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...BGM
AVIATION...BGM
HYDROLOGY...HWJIV
FIRE WEATHER...HWJIVHAZARDOUS WEATHER OUTLOOK...CORRECTED NATIONAL WEATHER SERVICE ALBANY NY 530 AM EDT MON AUG 15 2011 CTZ001-013-MAZ001-025-NYZ041>043-047>054-058>061-063>066-083-084- VTZ013>015-161100- NORTHERN LITCHFIELD-SOUTHERN LITCHFIELD-NORTHERN BERKSHIRE- SOUTHERN BERKSHIRE-NORTHERN SARATOGA-NORTHERN WARREN- NORTHERN WASHINGTON-SCHOHARIE-WESTERN SCHENECTADY- EASTERN SCHENECTADY-SOUTHERN SARATOGA-WESTERN ALBANY-EASTERN ALBANY- WESTERN RENSSELAER-EASTERN RENSSELAER-WESTERN GREENE-EASTERN GREENE- WESTERN COLUMBIA-EASTERN COLUMBIA-WESTERN ULSTER-EASTERN ULSTER- WESTERN DUTCHESS-EASTERN DUTCHESS-SOUTHEAST WARREN- SOUTHERN WASHINGTON-BENNINGTON-WESTERN WINDHAM-EASTERN WINDHAM- 530 AM EDT MON AUG 15 2011 ...FLOOD WATCH IN EFFECT THROUGH THIS EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE CAPITAL DISTRICT...SARATOGA LAKE GEORGE REGION...EASTERN CATSKILLS...MID HUDSON VALLEY...TACONICS...BERKSHIRES...NORTHWESTERN CONNECTICUT AND SOUTHERN VERMONT. .DAY ONE...TODAY AND TONIGHT. PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS. FLOOD WATCH. IN ADDITION...THERE IS A CHANCE OF MAINLY NON SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH THIS EVENING. ANY THUNDERSTORM WILL MOVE SOUTHEAST TO NORTHWEST 20 MPH. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY. THERE IS A CHANCE OF THUNDERSTORMS TUESDAY AFTERNOON AND AGAIN LATE THURSDAY INTO SATURDAY. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE REQUESTED TO SEND ANY REPORTS OF FLOODING OR NEAR BANKFULL STREAMS OR RIVERS AS WELL AS ANY RAINFALL AMOUNTS OF 2 INCHES OR MORE TO THE NATIONAL WEATHER SERVICE. NYZ032-033-038>040-082-161100- NORTHERN HERKIMER-HAMILTON-SOUTHERN HERKIMER-SOUTHERN FULTON- MONTGOMERY-NORTHERN FULTON- 530 AM EDT MON AUG 15 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN ADIRONDACKS AND MOHAWK VALLEY. .DAY ONE...TODAY AND TONIGHT. THERE IS A CHANCE OF MAINLY NON SEVERE THUNDERSTORMS TODAY INTO THIS EVENING. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY. THERE IS A CHANCE OF THUNDERSTORMS TUESDAY AFTERNOON AND AGAIN THURSDAY AFTERNOON INTO SATURDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
The Albany radar (KENX), 63 km away, was scanning. The volume nearest the first event began at 13:26 UTC.
1 flash flood. Local standard time, as filed.
Route 212 at Wittenberg Road in Mount Tremper was reported impassable due to flooding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in New York in 2011Every state in 2011This day in weather historyWarnings in New York, August 2011
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 336266.