Flash Flood Guidance
Issued by NWS

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000
AWUS01 KWNH 291950
FFGMPD
MAZ000-VTZ000-NYZ000-292356-

MESOSCALE PRECIPITATION DISCUSSION 0263...CORRECTED
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
350 PM EDT SUN MAY 29 2016

CORRECTED FOR UPDATED GRAPHIC

AREAS AFFECTED...CENTRAL TO NORTHERN NY...VT...WESTERN MA

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 291856Z - 292356Z

SUMMARY...SLOW MOVING...TRAINING CONVECTION MAY RESULT IN LOCALLY
HEAVY AMOUNTS RESULTING IN FLASH FLOODING.

DISCUSSION...SURFACE OBSERVATIONS SHOW A THERMAL
BOUNDARY...ESTABLISHED IN PART BY ONGOING CONVECTION...EXTENDING
FROM SOUTHERN NEW ENGLAND BACK INTO NORTHERN AND CENTRAL NEW YORK.
 SUPPORTED BY BROAD 15-20 KT SOUTHWESTERLY LOW LEVEL INFLOW...THE
LATEST MESOANALYSIS SHOWS MOISTURE CONTINUING TO POOL ALONG THIS
BOUNDARY...WITH VALUES INCREASING TO 1.5 TO 1.75 INCHES ACROSS THE
HIGHLIGHTED AREA.  PERSISTENT LOW LEVEL INFLOW IS EXPECTED TO
SUPPORT PWS AT OR ABOVE 1.5 INCHES ACROSS THE REGION THROUGH THE
AFTERNOON HOURS.  SOUTHWESTERLY LOW LEVEL INFLOW INTO THE WESTERN
EDGE OF THE BOUNDARY...IN CONCERT WITH WEAK MID-UPPER LEVEL
FORCING MAY SUPPORT TRAINING CONVECTION.  MEANWHILE...UPWIND
PROPAGATION VECTORS SUGGEST DEVELOPING CELLS WILL BE SLOW MOVING
AT FIRST.  WHILE THE POTENTIAL FOR SLOW MOVING...TRAINING CELLS
MAY RAISE THE THREAT FOR HEAVY RAINFALL ACCUMULATIONS AND FLASH
FLOODING...ONE LIMITING FACTOR MAY BE INSTABILITY.  WHILE LATEST
MESOANALYSIS SHOWS MUCAPE VALUES OF AROUND 1500-2500 J/KG...THE
HI-RES MODEL CONSENSUS SHOWS THESE VALUES DIMINISHING STEADILY AS
THE AFTERNOON PROGRESSES.

THE 12Z HI-RES MODELS AND THE LATEST RUNS OF THE HRRR SUGGEST THE
GREATEST POTENTIAL FOR HEAVY AMOUNTS WILL CENTER FROM THE EASTERN
ADIRONDACKS INTO NORTHWESTERN VT.  SOME GUIDANCE MEMBERS SHOW
AMOUNTS OF 2-4 INCHES FROM 18-00Z...WHILE THE SSEO MEAN
NEIGHBORHOOD PROBABILITIES SHOW A GREATER THAT 50 PERCENT CHANCE
OF 3-HR AMOUNTS EXCEEDING 3 INCHES DURING THE PERIOD FOR PARTS OF
THE REGION.

PEREIRA

...PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...ALY...BGM...BOX...BTV...BUF...

ATTN...RFC...MARFC...NERFC...

LAT...LON   44907418 44817319 44197292 42427293 42097379
            42717461 42297575 42167734 43307621 44237507




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