NOUS41 KBOX 172237 PNSBOX CTZ002>004-MAZ002>024-026-NHZ011-012-015-RIZ001>008-181400- PUBLIC INFORMATION STATEMENT SPOTTER REPORTS NATIONAL WEATHER SERVICE TAUNTON MA 637 PM EDT WED MAY 17 2006 ...IMPRESSIVE LONG DURATION RECORD CHALLENGING BOSTON AREA RAIN EVENT SUMMARY... THE FOLLOWING IS THE LISTING OF MOSTLY UNOFFICIAL STORM TOTAL OBSERVATIONS FOR THE PRIMARY PORTION OF THE STORM THAT CAUSED MAJOR TO RECORD FLOODING IN PORTIONS SOUTH CENTRAL NEW HAMPSHIRE AND THE NORTHEAST TIP OF MASSACHUSETTS. WHILE THIS STORM DELIVERED RAIN INTERMITTENTLY OVER AN APPROXIMATELY 100 HOUR PERIOD...IT WAS SUBDIVIDED INTO THREE SEGMENTS FOR DATA MANAGEMENT PURPOSES. PART ONE...WHICH COVERS THE CONNECTICUT RIVER VALLEY FLOODING DURING THE DAYLIGHT HOURS FRIDAY...IS OMITTED FROM THIS REPORT. ESSENTIALLY 5 TO 8 INCHES OCCURRED IN WESTERN HARTFORD COUNTY WITH LESSER AMOUNTS NORTH AND EAST OF HARTFORD. THE LAST SEGMENT...PART THREE...WILL NOT HAVE ANY SUPPLEMENTAL RAINFALL INFORMATION SINCE MOST AMOUNTS IN THE 24 HOUR PERIOD FROM MONDAY AFTERNOON THROUGH TUESDAY AFTERNOON WERE UNDER TWO INCHES AND DID NOT CONTRIBUTE TO ANY KNOWN NEW FLOODING. THIS LAST PORTION OF THE STORM WAS THE PRIMARY UPPER LEVEL CIRCULATION THAT WAS FINALLY LIFTING OUT ACROSS THE AREA...AFTER HAVING BEEN ESSENTIALLY STATIONARY FOR SEVERAL DAYS FROM THE OHIO VALLEY TO THE MID ATLANTIC STATES...DIRECTING HEAVY RAIN ASHORE INTO NORTHEAST MASSACHUSETTS. SO...THE MAIN PORTION OF THIS UNIQUE LONG DURATION STORM OCCURRED FROM FRIDAY EVENING THROUGH MONDAY MORNING AND ITS CONTENTS ARE BELOW. PENDING NATIONAL CLIMATIC DATA CENTER CERTIFICATION...A NEW STATE OF MASSACHUSETTS MONTHLY RAINFALL RECORD WAS LIKELY ESTABLISHED WITH THIS EARLY WARM SEASON 4 DAY RAIN EVENT. THE SALISBURY NEWBURYPORT CO-OPERATIVE OBSERVER MONTHLY TOTAL FOR MAY THROUGH 6 AM WEDNESDAY MAY 17TH...WAS 19.54 INCHES...AND WELL ABOVE THE PREVIOUSLY KNOWN MONTH OF MAY STATE RECORD OF 13.6 INCHES SET IN MAY 1984. EMBEDDED IN THE DATA BELOW OF THIS REPORT ARE THE DAILY RECORDS SET THIS PAST WEEKEND AT BOSTON. BOSTONS 8.49 INCHES THAT OCCURRED OVER 4 CALENDAR DAYS ENDING MAY 16TH IS FOURTH HIGHEST 96 HOUR TOTAL IN ALL OF THE BOSTON DATABASE DATING BACK TO 1872. THE RECORD IS THE 12.47 INCHES FOR THE 4 DAY PERIOD ENDING AUGUST 20TH 1955. WHEN YOU CAREFULLY REVIEW THE DATA....THE SECOND AND THIRD RANKING 4 CONSECUTIVE DAY RAINFALLS WERE ASSOCIATED WITH THIS AUGUST 1955 TROPICAL STORM DIANE. IN ESSENCE THEN...IN APPROXIMATELY 125 YEARS OF CONTINUOUS RECORD KEEPING FOR BOSTON...THIS WAS THE SECOND LARGEST 4 DAY RAINFALL EVER! THE MAY 2006 STORM COMPARES FAVORABLY TO THE OCTOBER 20-22 1996 EVENT FOR NORTHEAST MASSACHUSETTS IN THAT BOTH HAD LARGE AND NEARLY STATIONARY LOW PRESSURE SYSTEMS SOUTH OF OUR LATITUDE THAT ON SATELLITE IMAGERY APPEARED TO INGEST A PLUME OF TROPICAL MOISTURE WITHIN THE VAST CONVEYOR OF ONSHORE ATLANTIC FLOW. A PRELIMINARY REVIEW OF RAINFALL AND RIVER STAGE INFORMATION SUGGESTS THIS MAY 2006 EVENT WAS A BIT MORE SEVERE FOR PORTIONS OF ESSEX COUNTY IN NORTHEAST MASSACHUSETTS THAN THE OCTOBER 1996 EVENT. RAINFALL AMOUNTS APPEARED TO BE SLIGHTLY HEAVIER AND FLOOD OF RECORD STAGES WERE REACHED ON THE PARKER IPSWICH AND SAUGUS RIVERS IN ESSEX COUNTY OF THE NORTHEAST TIP OF MASSACHUSETTS...HIGHER READINGS THAN IN OCTOBER 1996. HOWEVER...THE INTENSITY OF THE RAIN THIS WEEKEND MAY HAVE BEEN SLIGHTLY LESS THAN THAT OF THE OCTOBER 96 EVENT. A POSSIBLY IMPORTANT DIFFERENCE BETWEEN 1996 AND 2006... ANTECEDENT GROUND CONDITIONS FOR THE FIRST 11 DAYS OF MAY SHOWED MONTHLY TOTALS IN THE 3 TO 6 INCH RANGE. BACK IN 1996...A QUICK SURVEY OF MIDDLETON HAVERHILL AND BOSTON DAILY DATA SHOWED ONLY AROUND 2 INCHES OF RAIN...ALLOWING FOR A LITTLE DRIER PRESTORM SOIL CONDITION. AS OF WEDNESDAY MAY 17TH...THE MONTHLY TOTALS IN ESSEX COUNTY MASSACHUSETTS ARE ALREADY WITHIN AN INCH OF 15 AT SEVERAL LOCATIONS WITH A COOPERATIVE OBSERVER REPORT OF 19.54 INCHES AT SALISBURY-NEWBURYPORT WHICH ALSO CORROBORATES THE 17.97 INCHES AT ROCKPORT. BOSTONS MONTHLY TOTAL AS OF 5 PM TUESDAY MAY 16TH IS 11.63 INCHES...RANKING SECOND FOR THE MONTH OF "MAY"...SO FAR...BELOW THE MONTHLY EXTREME OF 13.38 INCHES RECORDED IN 1954. OTHER HISTORICAL EVENTS THAT WERE REVIEWED WERE OCTOBER 2005 /INTERIOR SOUTHERN NEW ENGLAND/. 10/20-22/1996 NORTHEAST MASSACHUSETTS NORTHWARD. JAN AND APRIL 1996 EVENTS SNOWMELT RELATED APRIL 1987 SNOWMELT RELATED 8/18-20/1955 DIANE RELATED WHICH STILL APPEARS TO BE THE AREA WIDE BENCHMARK FLOOD EVENT. 9/17-22/1938 THE HURRICANE OF SEPT 38...PRECEDED BY SEVERAL DAYS OF EXCESSIVE RAIN. 3/9-22/1936 WHICH WAS HEAVILY SNOWMELT RELATED. APPRECIATION IS EXTENDED TO HIGHWAY DEPARTMENTS...COOPERATIVE OBSERVERS...SKYWARN SPOTTERS AND MEDIA FOR THESE REPORTS. THIS SUMMARY IS ALSO AVAILABLE ON OUR HOME PAGE AT WEATHER.GOV/BOSTON ********************STORM TOTAL RAINFALL******************** LOCATION STORM TOTAL TIME/DATE COMMENTS RAINFALL OF (INCHES) MEASUREMENT MASSACHUSETTS ...BRISTOL COUNTY... NEW BEDFORD 5.50 600 PM 5/15 SPOTTER MANSFIELD 4.78 222 PM 5/15 MAY TOTAL 7.02 TAUNTON 4.16 216 PM 5/15 NWS WEST MANSFIELD 4.15 925 PM 5/15 SPOTTER ...ESSEX COUNTY... SALISBURY 13.36 445 PM 5/15 MAY 2006 19.54 ROCKPORT 12.64 315 PM 5/15 MAY 2006 17.97 TOPSFIELD 12.60 503 PM 5/15 SPOTTER GLOUCESTER 11.75 1021 AM 5/15 SPOTTER SWAMPSCOTT 11.75 1023 AM 5/15 SPOTTER ANDOVER 11.60 1031 AM 5/15 BEVERLY 10.80 1000 AM 5/15 ASOS MARBLEHEAD 10.74 812 PM 5/15 SPOTTER SALEM 10.68 1019 AM 5/15 SALEM STATE METHUEN 9.19 1000 PM 5/15 SPOTTER LAWRENCE 8.73 1048 AM 5/15 ASOS ...FRANKLIN COUNTY... CONWAY 5.75 223 PM 5/15 ...HAMPSHIRE COUNTY... WILLIAMSBURG 4.10 222 PM 5/15 ...MIDDLESEX COUNTY... WAKEFIELD 11.19 621 PM 5/15 SPOTTER READING 9.49 334 PM 5/15 MAY 2006 10.90 NORTH CAMBRIDGE 8.99 221 PM 5/15 BILLERICA 8.47 1000 PM 5/15 SPOTTER STONEHAM 8.47 727 AM 5/15 SPOTTER BELMONT 7.60 500 PM 5/15 SPOTTER TYNGSBORO 7.40 123 PM 5/15 HUDSON 7.36 825 PM 5/15 SPOTTER LOWELL 7.02 1042 AM 5/15 SPOTTER TEWKSBURY 6.38 650 AM 5/15 HAM RADIO CHELMSFORD 6.15 703 AM 5/15 SPOTTER PEPPERELL 5.99 705 PM 5/15 SPOTTER BEDFORD 5.61 1050 AM 5/15 ASOS AYER 4.86 1039 AM 5/15 ...NORFOLK COUNTY... MILTON 4.85 917 AM 5/15 BLUE HILL OBSERVATORY RANDOLPH 4.75 905 PM 5/15 SPOTTER STOUGHTON 4.65 717 PM 5/15 SPOTTER SHARON 4.59 1034 AM 5/15 DEDHAM 4.45 752 AM 5/15 SPOTTER EAST WALPOLE 2.65 1052 AM 5/15 ...PLYMOUTH COUNTY... SCITUATE 9.25 844 AM 5/15 SPOTTER HINGHAM 7.93 706 AM 5/15 SPOTTER DUXBURY 6.01 1136 AM 5/15 SPOTTER EAST BRIDGEWATER 5.50 1033 AM 5/15 BROCKTON 4.55 1033 AM 5/15 MARION 4.00 1037 AM 5/15 ...SUFFOLK COUNTY... WINTHROP 10.93 255 PM 5/15 EAST BOSTON 8.30 1030 AM 5/15 LOGAN ASOS NEW HAMPSHIRE ...CHESHIRE COUNTY... KEENE 2.85 758 AM 5/15 NWS COOP FITZWILLIAM 2.70 120 PM 5/15 SWANZEY 2.32 1119 AM 5/15 NH DOT ...HILLSBOROUGH COUNTY... MANCHESTER 11.05 1023 AM 5/15 SPOTTER GOFFSTOWN 10.99 700 AM 5/15 MANCHESTER 8.60 1049 AM 5/15 ASOS NASHUA 6.50 1000 PM 5/15 SPOTTER RHODE ISLAND ...KENT COUNTY... WARWICK 4.24 1002 AM 5/15 TF GREEN ASOS ...NEWPORT COUNTY... TIVERTON 3.52 715 AM 5/15 NWS COOP ...WASHINGTON COUNTY... NORTH KINGSTOWN 4.13 930 AM 5/15 SPOTTER $$ DRAG/AED