2001 New Orleans, Louisiana (MSY)

views updated

2001 NEW ORLEANS, LOUISIANA (MSY)

The New Orleans metropolitan area is virtually surrounded by water. Lake Pontchartrain, some 610 square miles in area, borders the city on the north and is connected to the Gulf of Mexico through Lake Borgne on the east. In other directions there are bayous, lakes, and marshy delta land. The proximity of the Gulf of Mexico also has a great influence on the climate. Elevations in the city vary from a few feet below to a few feet above mean sea level. A massive levee system surrounding the city and along the Mississippi River offers protection against flooding from the river and tidal surges. The New Orleans International Airport is located 12 miles west of downtown New Orleans, between the Mississippi River and Lake Pontchartrain.

The climate of the city can best be described as humid with the surrounding water modifying the temperature and decreasing the range between the extremes. Almost daily sporadic afternoon thunderstorms from mid–June through September keep the temperature from rising much above 90 degrees. From about mid–November to mid–March, the area is subjected alternately to the southerly flow of warm tropical air and to the northerly flow of cold continental air in periods of varying lengths. The usual track of winter storms is to the north of New Orleans, but occasionally one moves this far south, bringing large and rather sudden drops in temperature. However, the cold spells seldom last over three or four days. The lowest temperatures observed are below 10 degrees. In about two–thirds of the years, the lowest temperature is about 24 degrees or warmer. The lowest temperatures in some years are entirely above freezing.

During the winter and spring, the cold Mississippi River water enhances the formation of river fogs, particularly when light southerly winds bring warm, moist air into the area from the Gulf of Mexico. The nearby lakes and marshes also contribute to fog formation. Even so, the fog usually does not seriously affect automobile traffic except for brief periods. However, air travel will be suspended for several hours and river traffic, at times, will be unable to move between New Orleans and the Gulf for several days.

Rather frequent and sometimes very heavy rains are typical for this area. There are an average of 120 days of measurable rain per year and an annual average accumulation of over 60 inches. A fairly definite rainy period occurs from mid–December to mid–March. Precipitation during this period is most likely to be steady rain for two to three day periods. April, May, October, and November are generally dry, but there have been some extremely heavy showers in those months. The greatest 24–hour amounts have exceeded 14 inches. Snowfall is rather infrequent and light. However, on rare occasions, snowstorms have produced accumulations over 8 inches.

While thunder occurs with most of the showers in the area, thunderstorms with damaging winds are infrequent. Hail of a damaging nature seldom occurs, and tornadoes are extremely rare. However, waterspouts are observed quite often on nearby lakes. Hurricanes have effected the area.

The lower Mississippi River floods result from runoff upstream. If the water level in the river becomes dangerously high, the spillways upriver can be opened to divert the floodwaters. Rainfall in the New Orleans area is pumped into the surrounding lakes and bayous. Local street and minor urban flooding of short duration result from occasional downpours.

Air pollution is not a serious problem. The area is not highly industrialized, and long periods of air stagnation are rare.

Based on the 1951–1980 period, the average first occurrence of 32 degrees Fahrenheit in the fall is December 5 and the average last occurrence in the spring is February 20.

NORMALS, MEANS, AND EXTREMES

NEW ORLEANS, LA (MSY)

LATITUDE:    LONGITUDE:    ELEVATION (FT):    TIME ZONE:    WBAN: 12916

29 59′ 34″ N  90 15′ 03″ W  GRND: 4  BARO: 7  CENTRAL (UTC + 6)

ELEMENTPORJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECYEAR
TEMPERATURE FNORMAL DAILY MAXIMUM3060.864.171.678.584.489.290.690.286.679.471.164.377.6
MEAN DAILY MAXIMUM5462.065.371.278.384.989.490.990.686.979.670.764.477.8
HIGHEST DAILY MAXIMUM558385899296100101102101948784102
YEAR OF OCCURRENCE198219721982198719531954198119801980199819971995AUG 1980
MEAN OF EXTREME MAXS.5477.479.482.586.591.494.695.895.693.288.683.279.987.3
NORMAL DAILY MINIMUM3041.844.451.658.465.270.873.172.869.558.751.044.858.5
MEAN DAILY MINIMUM5443.646.251.958.765.871.373.573.470.059.950.845.559.2
LOWEST DAILY MINIMUM5514162532415060604235241111
YEAR OF OCCURRENCE198519961980197119601984196719681967199319701989DEC 1989
MEAN OF EXTREME MINS.5426.429.935.843.654.163.669.268.459.744.334.828.446.5
NORMAL DRY BULB3051.354.361.668.574.880.081.981.578.169.161.154.568.1
MEAN DRY BULB5452.855.761.768.575.480.482.282.078.569.760.855.068.6
MEAN WET BULB1748.752.556.862.569.974.576.076.072.664.357.448.663.3
MEAN DEW POINT1744.247.952.358.266.472.073.773.769.660.453.344.759.7
NORMAL NO. DAYS WITH:
MAXIMUM 90300.00.00.00.23.114.420.419.88.90.90.00.067.7
MAXIMUM 32300.20.00.00.00.00.00.00.00.00.00.00.20.4
MINIMUM 32306.23.50.6 *0.00.00.00.00.00.00.84.715.8
MINIMUM 0300.00.00.00.00.00.00.00.00.00.00.00.00.0
H/CNORMAL HEATING DEG. DAYS304503161622800000301783491513
NORMAL COOLING DEG. DAYS3025175613330445052451239315761232655
RHNORMAL (PERCENT)3076737373747679797875777776
HOUR 00 LST3081808184858788888684858384
HOUR 06 LST3084838588899092928988878688
HOUR 12 LST3066636159606466676559636663
HOUR 18 LST3071666464656872737472767470
SPERCENT POSSIBLE SUNSHINE2246505662626359616164544857
W/OMEAN NO. DAYS WITH:
HEAVY FOG (VISBY 1/4 MI)535.74.23.51.60.90.20.10.20.31.63.54.526.3
THUNDERSTORMS532.22.94.04.25.89.814.712.46.61.92.02.168.6
CLOUDINESSMEAN:
SUNRISE–SUNSET (OKTAS)485.45.05.04.64.94.95.14.64.33.64.35.14.7
MIDNIGHT–MIDNIGHT (OKTAS)325.24.84.94.44.24.04.64.34.03.34.04.84.4
MEAN NO. DAYS WITH:
CLEAR486.97.57.87.98.98.34.67.29.614.310.27.7100.9
PARTLY CLOUDY487.16.48.010.411.212.514.613.810.67.98.27.4118.1
CLOUDY4816.914.315.211.710.99.211.810.09.88.911.515.9146.1
PRMEAN STATION PRESSURE(IN)2830.1130.0830.0029.9829.9429.9630.0029.9829.9630.0330.0830.1130.02
MEAN SEA–LEVEL PRES. (IN)1730.1530.1130.0530.0129.9830.0130.0430.0029.9930.0630.1130.1630.06
WINDSMEAN SPEED (MPH)399.49.99.99.58.16.96.26.17.57.88.89.28.3
PREVAIL. DIR (TENS OF DEGS)2336361616181823050405063618
MAXIMUM 2–MINUTE:
SPEED (MPH)548433640333639404632363948
DIR. (TENS OF DEGS)27212501282824020203262427
YEAR OF OCCURRENCE199819982001199720012001199819971998200020012000JAN 1998
MAXIMUM 5–SECOND:
SPEED (MPH)563514453444847485538445163
DIR. (TENS OF DEGS)33211021262524040102262433
YEAR OF OCCURRENCE199819982001199719992001199819971998200020012001JAN 1998
PRECIPITATIONNORMAL (IN)305.056.014.904.504.565.846.126.175.513.054.425.7561.88
MAXIMUM MONTHLY (IN)5519.2812.5919.0916.1221.1817.6213.1516.1218.9813.2019.8110.7721.18
YEAR OF OCCURRENCE199819831948198019952001199119771998198519891967MAY 1995
MINIMUM MONTHLY (IN)550.540.150.240.280.070.231.381.680.240.000.211.460.00
YEAR OF OCCURRENCE196819891955197620001979200019801953197819491958OCT 1978
MAXIMUM IN 24 HOURS (IN)556.085.607.878.0812.407.404.434.966.504.5112.666.8112.66
YEAR OF OCCURRENCE197819611948198819951988199619921971198519891990NOV 1989
NORMAL NO. DAYS WITH:
PRECIPITATION 0.013010.38.98.86.77.610.914.313.510.05.57.99.9114.3
PRECIPITATION 1.00301.52.01.71.21.52.01.71.61.91.01.51.819.4
SNOWFALLNORMAL (IN)300.*0.*T0.00.00.00.00.00.00.00.00.10.1
MAXIMUM MONTHLY (IN)510.42.0TTT0.00.00.00.00.0T2.72.7
YEAR OF OCCURRENCE1985195819931996198919501963DEC 1963
MAXIMUM IN 24 HOURS (IN)500.42.0TTT0.00.00.00.00.0T2.72.7
YEAR OF OCCURRENCE1985195819931996198919501963DEC 1963
MAXIMUM SNOW DEPTH (IN)482200000000012
YEAR OF OCCURRENCE196419581989FEB 1958
NORMAL NO. DAYS WITH:
SNOWFALL 1.0300.00.00.00.00.00.00.00.00.00.00.00.*0.0
PRECIPITATION (inches) 2001 NEW ORLEANS, LA (MSY)
YEARJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECANNUAL
19726.986.036.071.646.313.103.904.923.294.648.458.6563.98
19732.685.4012.1710.474.686.085.943.3711.075.074.048.3179.28
19748.465.536.645.529.843.835.666.707.582.265.884.8972.79
19752.953.645.326.698.0312.288.3510.113.974.0011.353.8180.50
19762.613.853.080.285.583.365.671.691.575.085.808.8147.38
19775.622.753.966.382.591.742.9116.1213.484.338.774.1572.80
197813.632.532.673.449.727.8210.3414.682.980.004.674.4276.90
19795.5512.493.314.904.380.2311.434.574.551.494.273.0760.24
19806.373.0910.0816.129.653.694.841.686.315.873.851.5473.09
19810.948.342.702.285.358.471.9211.104.782.031.105.5054.51
19822.767.882.565.861.195.4313.071.925.403.845.4510.2665.62
19833.3112.594.8814.863.7110.642.956.295.724.886.329.1585.30
19844.105.274.901.723.547.213.869.513.792.842.802.5352.07
19854.839.287.072.111.164.566.926.375.7413.200.964.7866.98
19863.492.931.881.501.618.873.606.741.422.877.905.0547.86
19878.887.384.392.273.4615.016.385.051.290.722.922.8860.63
19883.7411.318.909.251.6811.286.787.535.862.871.263.9474.40
19892.470.157.143.203.508.228.343.314.530.5119.816.2867.46
19907.5911.455.984.595.871.012.302.454.552.383.219.6761.05
199119.255.426.2715.2914.2810.7113.157.863.441.882.192.63102.37
19929.948.736.692.520.959.525.759.646.630.5515.275.6881.87
19936.212.345.656.827.234.965.772.262.473.672.432.9052.71
19943.250.544.822.833.679.358.954.595.612.301.394.6151.91
19953.664.947.893.8121.182.846.443.260.691.314.245.0765.33
19964.661.562.973.871.378.6010.328.763.962.593.105.5557.31
19976.326.882.574.915.036.973.942.250.811.368.092.5551.68
199819.284.285.974.390.433.386.568.3018.981.823.402.2579.04
19993.200.924.600.303.3712.204.055.212.875.460.283.8546.31
20002.251.812.411.130.075.461.382.356.501.1011.722.7038.88
20013.051.598.071.086.8517.626.977.416.305.132.542.9069.51
POR=72 YRS5.124.925.264.644.845.666.615.895.333.014.454.8660.59
AVERAGE TEMPERATURE (F) 2001 NEW ORLEANS, LA (MSY)
YEARJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECANNUAL
197258.656.161.969.873.980.879.481.179.670.456.655.368.6
197350.352.665.564.272.581.784.481.779.773.466.654.168.9
197463.355.967.369.075.878.180.380.477.066.959.855.369.1
197557.258.961.466.875.179.480.280.575.169.961.251.968.1
197650.658.264.868.572.378.381.281.577.864.052.750.666.7
197743.453.865.069.075.982.483.981.980.268.262.954.368.4
197844.145.059.971.476.981.282.683.281.169.767.155.968.2
197945.952.962.671.174.681.183.682.979.371.058.052.568.0
198056.152.062.066.277.983.385.885.583.568.860.053.669.6
198148.555.361.971.474.883.885.083.177.971.164.954.569.4
198254.555.065.969.876.581.581.482.276.870.462.559.469.7
198350.253.858.364.374.077.681.582.475.369.160.049.566.3
198446.653.959.367.573.777.478.879.276.373.558.862.467.3
198545.252.365.369.074.779.380.281.677.072.667.351.068.0
198651.259.260.667.276.781.083.281.681.070.466.353.269.3
198750.056.360.366.276.879.982.983.578.264.461.659.068.3
198849.453.260.968.473.378.581.681.479.868.065.656.068.0
198960.255.962.867.076.479.481.481.776.967.562.446.968.2
199057.261.363.367.676.282.682.383.079.668.162.359.070.2
199152.858.264.271.277.581.383.581.778.271.655.957.669.5
199251.158.362.066.472.880.683.179.678.569.557.458.268.1
199357.254.758.864.071.980.483.383.679.769.958.052.267.8
199450.056.960.869.675.181.480.881.377.870.865.356.568.9
199553.056.363.068.877.679.383.984.779.571.359.855.269.4
199652.955.958.467.178.180.682.881.179.070.463.357.368.9
199753.857.166.465.474.579.683.483.681.171.358.652.869.0
199856.155.959.867.578.883.785.384.681.173.365.459.170.9
199957.761.161.673.176.781.482.285.578.270.762.055.270.5
200056.460.666.068.980.181.784.684.479.369.859.949.670.1
200150.260.359.472.276.180.382.982.578.568.365.057.669.4
POR=72 YRS53.356.361.968.875.580.782.382.278.770.361.155.368.9

REFERENCE NOTES:

PAGE 1:

THE TEMPERATURE GRAPH SHOWS NORMAL MAXIMUM AND NORMAL MINIMUM DAILY TEMPERATURES (SOLID CURVES) AND THE ACTUAL DAILY HIGH AND LOW TEMPERATURES (VERTICAL BARS).

PAGE 2 AND 3:

H/C INDICATES HEATING AND COOLING DEGREE DAYS.

RH INDICATES RELATIVE HUMIDITY

W/O INDICATES WEATHER AND OBSTRUCTIONS

S INDICATES SUNSHINE.

PR INDICATES PRESSURE.

CLOUDINESS ON PAGE 3 IS THE SUM OF THE CEILOMETER AND SATELLITE DATA NOT TO EXCEED EIGHT EIGHTHS (OKTAS).

GENERAL:

T INDICATES TRACE PRECIPITATION, AN AMOUNT GREATER THAN ZERO BUT LESS THAN THE LOWEST REPORTABLE VALUE.

+ INDICATES THE VALUE ALSO OCCURS ON EARLIER DATES.

BLANK ENTRIES DENOTE MISSING OR UNREPORTED DATA.

NORMALS ARE 30–YEAR AVERAGES (1961–1990).

ASOS INDICATES AUTOMATED SURFACE OBSERVING SYSTEM.

PM INDICATES THE LAST DAY OF THE PREVIOUS MONTH.

POR (PERIOD OF RECORD) BEGINS WITH THE JANUARY DATA MONTH AND IS THE NUMBER OF YEARS USED TO COMPUTE THE MEAN. INDIVIDUAL MONTHS WITHIN THE POR MAY BE MISSING.

WHEN THE POR FOR A NORMAL IS LESS THAN 30 YEARS, THE NORMAL IS PROVISIONAL AND IS BASED ON THE NUMBER OF YEARS INDICATED.

0.* OR * INDICATES THE VALUE OR MEAN–DAYS–WITH IS BETWEEN 0.00 AND 0.05.

CLOUDINESS FOR ASOS STATIONS DIFFERS FROM THE NON–ASOS OBSERVATION TAKEN BY A HUMAN OBSERVER. ASOS STATION CLOUDINESS IS BASED ON TIME–AVERAGED CEILOMETER DATA FOR CLOUDS AT OR BELOW 12,000 FEET AND ON SATELLITE DATA FOR CLOUDS ABOVE 12,000 FEET.

THE NUMBER OF DAYS WITH CLEAR, PARTLY CLOUDY, AND CLOUDY CONDITIONS FOR ASOS STATIONS IS THE SUM OF THE CEILOMETER AND SATELLITE DATA FOR THE SUNRISE TO SUNSET PERIOD.

GENERAL CONTINUED:

CLEAR INDICATES 0–2 OKTAS, PARTLY CLOUDY INDICATES 3–6 OKTAS, AND CLOUDY INDICATES 7 OR 8 OKTAS. WHEN AT LEAST ONE OF THE ELEMENTS (CEILOMETER OR SATELLITE) IS MISSING, THE DAILY CLOUDINESS IS NOT COMPUTED.

WIND DIRECTION IS RECORDED IN TENS OF DEGREES (2 DIGITS) CLOCKWISE FROM TRUE NORTH. "00" INDICATES CALM. "36" INDICATES TRUE NORTH.

RESULTANT WIND IS THE VECTOR AVERAGE OF THE SPEED AND DIRECTION.

AVERAGE TEMPERATURE IS THE SUM OF THE MEAN DAILY MAXIMUM AND MINIMUM TEMPERATURE DIVIDED BY 2.

SNOWFALL DATA COMPRISE ALL FORMS OF FROZEN PRECIPITATION, INCLUDING HAIL.

A HEATING (COOLING) DEGREE DAY IS THE DIFFERENCE BETWEEN THE AVERAGE DAILY TEMPERATURE AND 65 F.

DRY BULB IS THE TEMPERATURE OF THE AMBIENT AIR.

DEW POINT IS THE TEMPERATURE TO WHICH THE AIR MUST BE COOLED TO ACHIEVE 100 PERCENT RELATIVE HUMIDITY.

WET BULB IS THE TEMPERATURE THE AIR WOULD HAVE IF THE MOISTURE CONTENT WAS INCREASED TO 100 PERCENT RELATIVE HUMIDITY.

ON JULY 1, 1996, THE NATIONAL WEATHER SERVICE BEGAN USING THE "METAR" OBSERVATION CODE THAT WAS ALREADY EMPLOYED BY MOST OTHER NATIONS OF THE WORLD. THE MOST NOTICEABLE DIFFERENCE IN THIS ANNUAL PUBLICATION WILL BE THE CHANGE IN UNITS FROM TENTHS TO EIGHTS (OKTAS) FOR REPORTING THE AMOUNT OF SKY COVER.

HEATING DEGREE DAYS (base 65 F) 2001 NEW ORLEANS, LA (MSY)
YEARJULAUGSEPOCTNOVDECJANFEBMARAPRMAYJUNTOTAL
1972–730002829331444735172114901628
1973–740001880355117274711600931
1974–750002419434127021018373001295
1975–76006162224174452059821001430
1976–770009337543866431811718002023
1977–78000431133426465561912001893
1978–7900016393245863471288201450
1979–800001323039627838515438001494
1980–810003519536350427512312001507
1981–820003610033336527812729001268
1982–830003114623445330921781101472
1983–840013718348356432119748201836
1984–85002142141466053596228001430
1985–86000124944342119516028001308
1986–87000288537046424216875001432
1987–880005814922249035116623001459
1988–89000129230118629215560001098
1989–900005314255925313610141001285
1990–91000621222443711961058001108
1991–920002231226242620312854501412
1992–93000224021824828520982001284
1993–940004225939946426317749001653
1994–95000167226837525712333001144
1995–960001618635838030724854101550
1996–97000171162533732485844001109
1997–980003820238327325121025001382
1998–990002482432631501182100845
1999–00000231123182951816333001025
2000–010043422746945318118416001568
2001–0004460249
COOLING DEGREE DAYS (base 65 F) 2001 NEW ORLEANS, LA (MSY)
YEARJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECANNUAL
197250263817528147945350744620048192722
1973099699247507607524448289136242986
197471271471443454024844843689345452655
1975344580132321440479491314171114162637
1976418100132234404509518390681302390
197701012314534552859353246315156162962
19785039203380493553569489169110493059
19790146319830749158155943520625162895
19801013708540955465364056116051173223
198101235210311570627565396231102123071
198249616018236650451754136320878663040
198300166728638551854531717142102357
1984063113028137943644835128633712452
198501078154308437480521366251124132742
1986040329937048757352448820312792952
198734301203734565625804024853422673
1988141549131263411523513448113118302628
19894643951243634395155253651377062728
199017405612735353854556744816650622969
19912128820239649658052440223347403022
19920184110325847256845940814920142510
199313426612224685725854472005782663
19944405419132050149551339020494122818
199510206715539943459461544421639593052
199613504712441247355850742718970212891
19973431107673014455765834892381992899
1998415910843556863561348926768703317
199941482027336949754364340320929233098
200035581031594775066166104391927903274
20010561923935346956455041015369292911
SNOWFALL (inches) 2001 NEW ORLEANS, LA (MSY)
YEARJULAUGSEPOCTNOVDECJANFEBMARAPRMAYJUNTOTAL
1972–730.00.00.00.00.00.00.10.60.00.00.00.00.7
1973–740.00.00.00.00.0T0.00.00.00.00.00.0T
1974–750.00.00.00.00.00.00.00.00.00.00.00.00.0
1975–760.00.00.00.00.00.00.00.00.00.00.00.00.0
1976–770.00.00.00.00.00.0T0.00.00.00.00.0T
1977–780.00.00.00.00.00.0TT0.00.00.00.0T
1978–790.00.00.00.00.00.0T0.00.00.00.00.0T
1979–800.00.00.00.00.00.00.00.0T0.00.00.0T
1980–810.00.00.00.00.00.00.00.00.00.00.00.00.0
1981–820.00.00.00.00.00.0T0.00.00.00.00.0T
1982–830.00.00.00.00.00.00.00.00.00.00.00.00.0
1983–840.00.00.00.00.00.00.00.00.00.00.00.00.0
1984–850.00.00.00.00.00.00.40.00.00.00.00.00.4
1985–860.00.00.00.00.00.00.00.00.00.00.00.00.0
1986–870.00.00.00.00.00.00.00.00.00.00.00.00.0
1987–880.00.00.00.00.00.00.0T0.00.00.00.0T
1988–890.00.00.00.00.00.00.00.0T0.0T0.0T
1989–900.00.00.00.00.00.50.00.00.0T0.00.00.5
1990–910.00.00.00.00.00.00.00.0TT0.00.0T
1991–920.00.00.00.00.00.00.00.0T0.00.00.0T
1992–930.00.00.00.00.00.00.00.0T0.00.00.0T
1993–940.00.00.00.00.00.00.0T0.00.00.00.0T
1994–950.00.00.00.00.00.00.0T0.00.00.00.0T
1995–960.00.00.00.00.0T0.00.00.0T
1996–97
1997–98
1998–99
1999–00
2000–01T
2001–
POR=49 YRS0.00.00.00.0T0.10.00.1TTT0.00.2

More From encyclopedia.com

About this article

2001 New Orleans, Louisiana (MSY)

Updated About encyclopedia.com content Print Article

You Might Also Like

    NEARBY TERMS

    2001 New Orleans, Louisiana (MSY)