BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 TUESDAY OCTOBER 08 2002 DISCUSSION FOR 10/8/2002....2 P.M. MORNING LOW TEMP OF 42 DEGREES COLDEST OF THE SEASON TO DATE... DEWPOINTS DROP TO NEAR 30 DEGREES BY LATE MORNING... VISIBILITY UP TO AT LEAST 90 MILES BY EARLY AFTERNOON.. ONE YEAR AGO TODAY A TRACE OF SNOW WAS RECORDED HERE A cold frontal passage Monday afternoon brought a wind shift from WSW to NW at 5:21 P.M. About an hour later peak wind gusts reached 41 MPH NW on the Maximum, Inc. Merlin and Aerovane wind system at 6:22 P.M. The official peak gust on the 420C wind system was 31 MPH NW and also on ASOS. A sharp drop in dewpoint temperatures was registered from near 60 degrees to the middle 40's with this frontal passage. The reading at 5 p.m. was 62 degrees and by 7 p.m. the dewpoint had dropped to 43 degrees. This morning's minimum temperature of 42.2 degrees in the Hazen shelter sets the new lowest of the season to date; the previous low was 46 degrees back on September 29th. Visibility increased to 80 to 90 miles today in the cool and very dry airmass. The following taken from the Blue Hill Observatory Journal 2001: 10/8/01 - COLUMBUS DAY FIRST SNOWFLAKES OF THE SEASON JUST BEFORE 9 A.M. EQUALS RECORD FOR THE EARLIEST TRACE OF SNOW ON RECORD DATING BACK TO 1885... THE OBSERVATIONS FOR TODAY.... 10/8/2002 TUE 8 A.M. BHO SA 1155 CLR 80 238/45/37/3509/023/ FEW SC OFFSHR DSNT ENE-SE WND GRDLY VEERING/ 8/500/ 53032 10048 20042 11 A.M. BHO SA 1455 CLR 80 252/54/29/3511G17/027/ LINE CU DSNT E-SSE CUFRA/ CU FRMG SW-NW WND 33V03/ 8/100/ 51014 BHO SA 1755 CLR 80 250/56/32/3407/026/ FEW CUFRA/SML CU WND 30V02/ 8/100/ 58002 10057 20045 THE DATA RECORDED FOR MONDAY OCTOBER 07 TEMPERATURES ARE CALENDAR DAY MIDNIGHT TO MIDNIGHT EASTERN STANDARD TIME MAX: 68 MIN: 49 ASOS MAX: 68 ASOS MIN: 49 MEAN: 59 [+ 4] NORMAL HIGH/LOW/MEAN: 64/46/55 OCTOBER DEPARTURE TO DATE: +46 deg. OCTOBER AVERAGE: 6.4 DEGREES WARMER THAN NORMAL PRECIPITATION FOR 10/8 AS OF 8 A.M. EDT 24 HRS ENDING 8 A.M.......TRACE ASOS......................0.00 INS. OCTOBER TOTAL ...........0.12 INS. DEPARTURE FROM NORMAL....-0.86 INS. OCTOBER ASOS TOTAL........0.13 INS. PRECIP. TOTAL YEAR 2002...35.60 INS. DEPARTURE FROM NORMAL.....-2.98 INS. ASOS TOTAL FOR 2002.......33.48 INS. WIND DATA FOR MONDAY OCTOBER 07, 2002 PEAK GUST ASOS: 31 MPH NW AT 6:23 P.M. PEAK GUST 420C: 31 MPH NW AT 6:22 P.M. PEAK GUST AERO: 36 MPH NW AT 6:22 P.M. *** *** PEAK GUST MAXIMUM INC MERLIN 41 MPH NW OCT. 2002 PRELIMINARY DATA....ALL IS CALENDAR DAY DATA.... BELOW IS ORDER OF DATA REPORTED.... MAX/MIN/MEAN/DEP/PRECIP/SUNSHINE/ OFFICIAL 420C WIND GUST Aero = Aerovane recording wind system gust when significantly higher ... data as yet not available TSTM = thunderstorm day ASOS TWO MINUTE MAXIMUM WIND ON THE RIGHT FROM ASOS IS AUTOMATED SURFACE OBSERVING SYSTEM 10/1 78/58/68/+11/0/649/92/ 29 SW " " = 23 SW 10/2 83/63/73/+16/0.01/618/88/ 27 WSW " " = 21 WSW 10/3 69/50/60/+4/0.07/.../../ 28 ENE " " = 21 NE 10/4 64/49/57/+1/0.01/.../../ 32 SE " " = 26 SSE 10/5 78/54/66/+11/0.03/.../../ 43 S " " = 35 SSE ** 10/6 60/48/54/-1/0/.../../ 27 NE " " = 20 ENE 10/7 68/49/59/+4/TRACE/.../.. 31 NW " " = 25 SSW *** 10/8 morning low temp. 42, lowest of the season to date ** Aero peak gust 46 MPH S *** Aero peak gust 36 MPH NW RECORDS FOR OCTOBER 08 HIGH 81 IN 1916,1990 LOW 28 IN 1919 PRECIP 2.31 IN 1891 SNOWFALL TRACE IN PEAK GUST 60 MPH NE IN 1996 RECORDS FOR OCTOBER 09 HIGH 81 IN 1909 LOW 29 IN 1907,1937 PRECIP 2.54 IN 1976 SNOWFALL 0.6 IN IN 1888 PEAK GUST 81e MPH S IN 1976 RECORDS FOR OCTOBER 10 HIGH 85 IN 1949 LOW 27 IN 1929 PRECIP 2.02 IN 1998 PEAK GUST 59 MPH WNW IN 1958 RECORDS FOR OCTOBER 11 HIGH 80 IN 1919,1949 LOW 28 IN 1993 PRECIP 0.96 IN 1903 PEAK GUST 66e MPH WNW IN 1941 RECORDS FOR OCTOBER 12 HIGH 87 IN 1954 LOW 31 IN 1906 PRECIP 1.53 IN 1948 SNOWFALL TRACE IN 1941 PEAK GUST 55 MPH NW IN 1963 e = estimated Robert Skilling