October 21-31 2005 - This analysis will be the last of the season from NOAA. The experimental product will begin next period.

During the period from October 21-31, 2005, the African ITCZ was located near 11.8 degrees north latitude, when averaged from 15W-35E and over the entire 11-day period. This compares to a long term mean position of 12.4 degrees north, and a position during the same period last year of 11.8N. The ITCZ surged southward during the past two weeks, with the position jumping nearly two and a half degrees to the south during the last 11 days. It is evident that most of the precipitation has moved south of the Sahel, except for western zones such as Mali, Mauritania, and Senegal, where abnormally heavy rains continue sporadically. In the western area, from 10W-10E, the latest position of the ITCZ was near 12.0N, compared to a long term mean of 12.9N and a position during the last dekad of 14.4N. In the east, from 20E-35E, the latest position of the ITCZ was around 10.7 degrees north, compared to a climatological mean of 11.4N and a position during the previous period of 11.6N.

October 11-20 2005 - The African portion of the Intertropical Convergence Zone was located near 13.8 degrees north latitude when averaged from 15W-35E longitude and over the ten-day period. This is nearly on target of the 1988-2004 climatological mean, and around one and a half degrees north of the position last year during the same period. In the western zone (from 10W-10E) the ITCZ is currently located near 14.4N, compared with the long term mean of 14.5N and a position last year of 13.0N. This is around 1.4 degrees south of the position during the previous period. In the east (from 20E-35E) the ITCZ is located near 13.4N, compared with 12.8N and 12.0N for the long term mean and last year positions, respectively. All in all, the ITCZ continues to track to the south at a near normal rate as seasonal rains recede from the Sahel.

October 1-10 2005 - The African portion of the Intertropical Convergence Zone continues to be located very close to its long term mean position, with the main exception in the extreme western areas, where the front has exhibited an erratic movement during the past month. This unusual movement is associated with the abnormally heavy rains that have been observed in the western Sahara region of Africa during the later portion of the season. Overall, the current position of the ITCZ was located near 14.9 degrees north latitude when averaged over the entire period and from 15W-35E. This compares with a long term mean of 15.1N and a position last period of 16.2N. In the western defined region (10W-10E), the ITCZ is currently located near 16.0N, compared with the climatological position of 15.9N and a 2004 position during the same period of 14.6N. In the east (from 20E-35E) the ITCZ is currently located near 13.9N, compared to a long term mean of 14.0N and a 2004 position of 13.7N. All in all, the early northward advancement of this season's ITCZ, accompanied by a near normal southward recession, has led to a longer period of monsoonal rainfall throughout much of the Sahel. This in turn has led to a generally favorable crop and pasture condition in the region, with occasional pockets of dryness locally.

September 21-30 2005 - The African portion of the Intertropical Convergence Zone was located near 16.2 degrees north latitude during this period, compared to a long term mean position of 15.9N and a position of 15.7N during the previous period. All in all, the ITCZ remained fairly stationary, with the most movement seen in the western area of Senegal, Mauritania, and Mali. This northward movement in the west was associated with abnormally heavy rains in the region of The Gambia, Guinea-Bissau, eastern Senegal, and western Mali. For the record, the western area (from 10W-10E) saw the ITCZ located near 17.0 degrees north during the past ten days, compared to a climatological mean of 16.6N and a position during the last poeriod of 16.7N. In the east (20E-35E), the ITCZ was more stationary and was located near 15.1N compared to the long term average of 14.7N.

September 11-20 2005 - The African portion of the Intertropical Convergence Zone has continued its southward progression during the past ten days, and was located on average near 17.4 degrees north during September 1-10 2005. This compares with a long term mean position of 17.3N and a 2004 position of 16.3N during the same period. Overall, the ITCZ moved approximately 0.6 degrees south from its position during the final ten days of August 2005, though the convergence zone fluctuated dramatically during the period with the passage of African Easterly Waves over the region and cold fronts originating north of the continent. The ITCZ in the west and east, respectively, is following the long term mean southward progression very closely. In the west (10W-10E), the current position is near 18.5N, compared to last period at 18.8N and the long term mean position of 18.3N. In the east (20E-35E), the ITCZ is currently near 16.1N, compared to a long term mean of nearly 16.0N and a position during the past period of 17.3. The quick receding motion of the ITCZ in the east was associated with a marked decreased in precipitation over the Darfur region in Sudan and the surrounding areas.

September 1-10 2005 - The African portion of the Intertropical Convergence Zone has continued its southward progression during the past ten days, and was located on average near 17.4 degrees north during September 1-10 2005. This compares with a long term mean position of 17.3N and a 2004 position of 16.3N during the same period. Overall, the ITCZ moved approximately 0.6 degrees south from its position during the end of August 2005, though the convergence zone fluctuated dramatically during the period with the passage of African Easterly Waves over the region and cold fronts originating north of the continent. The ITCZ in the west and east, respectively, is following the long term mean southward progression very closely. In the west (10W-10E), the current position is near 18.5N, compared to last period at 18.8N and the long term mean position of 18.3N. In the east (20E-35E), the ITCZ is currently near 16.1N, compared to a long term mean of nearly 16.0N and a position during the past period of 17.3. The quick receding motion of the ITCZ in the east was associated with a marked decreased in precipitation over the Darfur region in Sudan and the surrounding areas.

August 21-31 2005 - Based on the past three periods, it appears that the African portion of the Intertropical Convergence Zone peaked around ten days earlier (during August 1-10) than normal (August 11-20) and has begun its retreat southward in most all regions. Although the western region of the ITCZ (10W-10E) did peak so early, the maximum northward position was near normal and the current position is very close to the long term mean of 19.3N. In the east (from 20E-35E) the ITCZ also peaked ten days early, though its maximum northward position this year was almost a degree and a half further north than normal. Thus, the current location remains almost a degree north of normal for the period. Overall, the ITCZ was located near 18.0 degrees north when averaged from 15W-35E and over the entire 11-day period. This compares to a normal position of around 18.2N for the long term and 17.3N during the same period in 2004.

August 11-20 2005 - What a ride for the western region of the African ITCZ during this period! Though it shows a near constant latitude compared to the previous period, for the region averaged from 10 degrees west to 10 degrees east, this is highly misleading due to the fact that the position is averaged for the ten day period. The fact is, that two strong Easterly Waves passed thru the region beginning on August 14th, brought rainfall to much of western Africa, and caused a very large daily fluctuation in the ITCZ. For example, the ITCZ near 5 degrees west longitude fluctuated from nearly 28 degrees north on August 16th to around 18 degrees north on August 17th. Strong northerly winds accompanied this movement, with dry air plunging southward to southern Burkina on the 16th. For the record, the ITCZ was located near 18.8N during the period, compared to a normal position of around 18.7N, and a position last period of 19.0N. Judging on the latest analysis, it appears that the ITCZ has reached its maximum northerly peak, at least in the eastern areas of Africa, though it is yet to be determined if such is the case in the west.

August 1-10 2005 - The African portion of the Intertropical Convergence Zone was located near 19.0 degrees north latitude, compared to the long term mean position of 18.5N, and the previous location of 18.1N. Though the next ten days normally signifies the peak northward position of the ITCZ, that corresponding latitude was reached roughly forty days ago. This is not to say that the 2005 seasonal ITCZ reached its northward peak forty days ago, since the current location is the furthest north of the season to date. In the west (from 10W-10E), the ITCZ was located near 19.6N during the current period, compared to a long term mean of 19.4N and a position last period of 18.5N. In the east (from 20-35E), the ITCZ was located near 18.6N, compared to a long term mean of 17.2N and a position last period of 18.0N. All in all, it is yet undetermined if the ITCZ has reached its northward peak for the 2005 season.

July 21-31 2005 - The African portion of the ITCZ was located near 18.1 degrees north latitude, compared with the 1988-2004 mean position of 18.3N, a previous position of 18.2N, and a position during the same period 2004 of 18.5N. While the ITCZ continued its northward movement roughly in the area east of 10 degrees E longitude, it moved south from its position during the previous period in areas to the west. Strong winds from the north after the passage of an Easterly Wave on July 24th forced the convergence zone to the south over Mauritania and Mali, leading to the displacement from last period. In fact, examining the west region of the ITCZ (10W-10E), the current position of 18.5 degrees north is almost a full degree south of both the climatological normal and its position from July 11-20. The eastern (20-35E) region did continue to move north, and its current location of 18.0N is around 1.4 degrees north from the long term mean.

July 11-20 2005 - The African portion of the ITCZ continues to be located north of normal, except over the region from eastern Niger to western Chad. On average, during the current period, the ITCZ was located near 18.2 degrees north latitude, compared to the normal of 17.5N. This northward bias can be seen in positive rainfall anomalies in areas near Sudan and Eastern Chad, as well as near Mauritania, Mali, and Western Sahara. In the west, from 10 degrees west to 10 degrees east, the ITCZ was located near 19.4N, compared to the long term mean of 18.6N. In the east from 20-35E, the ITCZ was located near 17.2N, compared to the climatological normal of 16.0N. Overall, the convergence zone did not move significantly from the first ten days of July, due to a southward push in central Africa and northward movements to the west and east.

July 1-10 2005 - The African portion of the ITCZ was located near 18.1 degrees north latitude when averaged over the ten day temporal period and from 15 degrees west to 35 degrees east longitude spatially. This is well north of the climatological 1988-2004 location of around 16.6 degrees north. This is also slightly northward from last year's position of 17.8 degrees north. The significant northward bias of the ITCZ corresponds very well this period with the anomalously heavy rainfall in much of Sahelian Africa. The latest ITCZ positions are well above normal and are actually close to the climatological peak northward extent of the monsoonal oscillation.

June 21-30 2005 - The Intertropical Discontinuity was nearly stationary over much of Africa. In the west, from 10 degrees west to 10 degrees east, the ITD was at an average of 16.9 degrees north latitude or 0.1 degree latitude north of normal. In the east, from 20 degrees east to 35 degrees east, the average position of the ITD remained nearly the same at 14.7 degrees north latitude or 0.2 degrees north of normal. A cold front that had brought the ITD northward over Niger and eastern Mali has moved away, allowing nearly normal conditions to return to the area.

June 11-20 2005 - The African portion of the Intertropical Discontinuity was located at approximately 16.0 degrees north latitude when averaged over the ten day period and from 15 degrees west to 35 degrees east longitude. This current location is approximately 0.4 degrees north from the position during the previous period, and 0.8 degrees north from the climatological 1988-2004 mean. During the period, a low pressure region and associated cold front pushed through the Mali/Niger region, bringing unusually heavy precipitation to the area and helping to push the ITCZ to the north. In Senegal, the ITCZ has moved into the region, as light seasonal rains have begun. In the west (from 10W-10E), the ITCZ was nearly stationary, and was located near 17.7N compared to the long term mean of 16.2N. In the east, from 20E-35E, the ITCZ was located near 14.2 degrees north latitude, compared to the long term normal of 13.9N.

June 1-10 2005 - The African portion of the Intertropical Disontinuity was located near 15.9 degrees north latitude, compared to the climatological mean of 14.7 north and the previous position of 14.8N. This latest position represents a significant northward shift in the location of the convergence zone. The western region of the ITCZ moved northward during the previous period while, on average, the eastern region remained at the same latitude. In the west, the latest position of the ITCZ was near 17.5N, which is north of the climatological mean position of 15.9N. During May 21-31, the mean position was 15.3N. In the east, the current position is near 14.3N, which is the same position as last period. This is north of the climatological mean position of 13.5N.

May 21-31 2005 - The African portion of the Intertropical Discontinuity was located near 14.8 degrees north latitude, compared to the climatological mean of 14.1 north and the previous position of 12.4 N. This latest position represents a significant northward shift in the location of the convergence zone east of the Prime Meridian. In the west, the latest position of the ITCZ was near 15.3 N, which is the climatological mean position. During May 11-21, the mean position was 13.7N. In the east, the current position is near 14.3N, compared to 12.9 N and 10.9 N for the long term mean and previous period, respectively.

May 11-20 2005 - The African portion of the Intertropical Discontinuity was located near 12.4 degrees north latitude, compared to the climatological mean of 13.4 north and the previous position of 14.1N. This latest position represents a significant southward dip in the location of the convergence zone, and corresponds well with the lack of rains near the Sahelian region, especially in central Africa. Both the western and eastern regions of the ITCZ moved southward during the previous period and both are now south from the long term mean locations. In the west, the latest position of the ITCZ was near 13.7N, compared to the climatological mean of 14.6N and that during May 1-10 of 15.8N. In the west, the current position is near 10.9N, compared to 12.1N and 12.2N for the long term mean and previous period, respectively.

May 1-10 2005 - The African portion of the Intertropical Convergence Zone was located near 14.1 degrees north latitude when averaged over the entire period and from 15W-35E longitude. This is nearly 1.7 degrees northward from its position during the last ten days of April, and around 1.4 degrees north from its long term mean location (1988-2004). While the ITCZ over Sudan remained nearly stationary, areas to the west saw the convergence zone move rapidly northward. In fact, rains were seen during the past ten days in many locations further north from last period, especially near central Mali and southern Niger. In the east, rainfall remained very active in areas of southern Darfur in Chad and in much of the Ethiopian Highlands. For the record, the western area of the ITCZ (10W-10E) was located near 15.8N, compared to a long term mean of 13.7N and a value last period of 13.3N. From 20N-35N, the latest position of the ITCZ was near 12.2N, compared to a normal location of 11.4N and 12.0N during the final ten days of April.

April 21-30 2005 - The Africa portion of the ITCZ was located near 12.4 degrees north latitude when averaged over the entire period and from 15 degrees west to 35 degrees east longitude. This compares to a position last year of 12.2N and the 1988-2004 long-term mean of 21.1 for the same periodd. The ITCZ progressed northward at a strong rate from the previous period, and a good part of the southward biases that were exhibited from April 11-20 have been dissolved. This northward movement has resulted in positive rainfall anomalies throughout much of central and western Africa, though dryness was seen in parts of Guinea, Sierra Leone, and Liberia during the past ten days. The current position of the ITCZ as averaged from 10W-10E is around 13.3 degrees north, very close to the long-term climatological mean, though around half a degree south from its position during the same period last year. The eastern ITCZ region was located near 12.0N, compared to a long-term mean of 10.7N.

April 11-20 2005 - The ITCZ has moved southward since the first ten days of April over Guinea, Sierra Leone and southwestern Mali. Unusually strong northerly winds off of the African west coast have pushed the ITCZ well south of its climatological position. Further east, the ITCZ has moved northward across eastern Burkina Faso, Nigeria, Cameroon, Chad and Sudan. The Intertropical Front in these areas appears to be well-matched with the northward leading edge of monsoonal precipitation. By the numbers, the current location of the ITCZ in an area averaged over the ten day period and from 10W-10E is near 11.4 degrees north latitude, compared to the long term mean 0f 12.5 degrees north. This is well south of normal. However, return flow from off of the tropical Atlantic has kept rain falling north of the ITCZ across Guinea, Sierra Leone and southwestern Mali. From 20-35E, the current ITCZ location is near 9.9 degrees north, which is the long term mean position. This has allowed seaonal showers to advance across southern Chad, southern Sudan, northern Cameroon and northern Nigeria.

April 1-10 2005 - The latest ITCZ position is very close to normal in the western regions of Africa, though a southward bias exists in the east. The Intertropical Front appears to be well-matched the northward leading edge of monsoonal precipitation during the current period, with rains progressing into areas of Guinea, Burkina Faso, southern Chad, and southern Sudan to name a few locations. By the numbers, the current location of the ITCZ in an area averaged over the ten-day period and from 10W-10E is near 11.1 degrees north latitude, compared to the long term mean of near 11.1 degrees north. From 20-35E, the current ITCZ location is near 7.8N, compared to a long term mean of 8.8N. This southward displacement from normal is contributing to abnormal dryness in parts of southern Sudan.