Weather Forecast for Santarém Released: July 22, 2001, 10 local time Weather conditions today (Sunday): The convective line with vigorous Cbs that was seen yesterday afternoon along the Northern coast of Brazil, near Belém, arrived at Santarem by 06Z today as a weak line of Cumulus Congestus and continued propagating westward. The Belém sounding at 0Z entered the anvil and showed saturated conditions from 450 hPa up to the tropopause. The line today is forecast to continue due west with daytime intensification of convection. Yesterday, low level easterly winds were strong up to 650 hPa with a westerly upper level jet. These are very favorable conditions for propagating squall lines in the region. Today the low level jet is shallower and the upper level jet is not so strong; RAMS does not organize convection as well as in the previous 2 days. This afternoon, fair weather conditions are forecast for the Santarém area. Forecast for the next days: The CPTEC and NCEP global models indicate a mid to low level drying for the next 2-3 days with a reduction of CAPE after Tuesday (24). The Atlantic easterly wave that was seen approaching the northern coast has lost its structure. Winds at 700 hPa remains parallel to the coast at Belém and are weaker in the next 2 days; the RAMS forecast shows a maximum wind speed at 800 hPa with diminished vertical shear. Thus we will see a few days with conditions more favorable for the development of local circulation. According to the global models, the trade winds close to the surface will be weaker on Monday and Tuesday (23 and 24). After the 25th a polar high pressure area is seen to merge with the subtropical high and the trade winds should intensify again. Weather conditions today July 26, 2001 Regional model indicates nighttime/early morning convective precipitation mostly over the Amazon river (scattered cells) evolving for mostly clear skies with shallow Cu between 12 and 15 UTC. Regions affected by yesterdays isolated showers have clear skies this morning, without cumulus. Organized convective precipitating cells are predicted to develop mostly along the right margin of the Tapajos with small amounts of accumulated precipitation near 18Z (about 1-2mm/h average), extending to the east between 18 and 21Z and more intense (2-4 mm/h average). Instability indices suggest that the most active cells will be located to the SE of Santarem and to the north of the Amazon. The maximum depth of the mixed layer is predicted to be of the order of 1200m in the late afternoon. Trajectories in the mixed layer will be mostly from the NE. Forecast for July 27th The regional model indicates a similar evolution for tomorrow, with convective precipitating cells developing along the right margin of the Tapajos in the afternoon but smaller total accumulated precipitation than on the 26th. Instability indices also indicate smaller probability of active convective cells during the late afternoon/early evening. Air parcel trajectories are predicted to be mostly from the E. The predicted depth of the mixed layer is similar to the 26th. Thus, a drying trend and a slow shift for more east/west trajectories are the major features for the 27th. Extended range forecast: Global models continue to indicate a drying trend in the Santarem area as well as south of the Amazon. Intensity of trades are predicted to decrease after the 28th as a significant cold outbreak reaches the southern/southeast Brazil with the "friagem" on the SW Amazon beginning on the 28th. However, the long range forecast does not indicate that the remnants of the polar air mass will reach the eastern Amazon. As a result of the movement of the polar high to the Atlantic, the trades are expected to increase again by the 30-31th. After some delay today, caused by failure of the 12 UTC forecast in Săo Paulo and gas transport here in Santarem, here is the latest forecast: Forecast for July 27th The friagem is already reaching the Southwestern Amazon region, maximum temperature today in Vilhena is 22C while Manaus is stil in 32C. The overall pattern is similar to yesterday. More intense convection is expected to develop along the right margin of the Tapajos by 15-18Z (in fact it did!! we got wet at Pindobal at 13:00 LT). Scattered showers are expected to evolve during the afternoon over the whole area, mainly to the east and north of Santarém but the instability indices maintain favorable conditions for showers up to about 03 UTC. Precipitation rates during the day are of the order of a few mm/3hr in a mean sense but locally much higher in view of the instability indices. Maximum height of the mixed layer is expected to be of the order of 1.1 to 1.2 km (the model seems to have overestimated the height by about 100m yesterday). The trajectories are expected to be from the E/NE in the mixed layer during the day (less shift to E than predicted yesterday). Forecast for July 28th The regional model indicates a similar evolution for tomorrow, with convective precipitating cells developing along the right margin of the Tapajos in the afternoon but larger total accumulated precipitation than on the 27th along the river but less widespread convection to the east of Santarem (based on the instability indices - it will be nice to verify this one!!!). Air parcel trajectories are predicted to be mostly from the SE during the day. The predicted depth of the mixed layer is similar to the 27th. Extended range forecast: Global models confirm the "friagem" on the SW and W Amazon. Temperature will drop several degrees as the wind shifts to the south. The minimum temperatures on the western Amazon will be observed on the 29th and the trades should get stronger on the 30th as the subtropical high in the Atlantic gets more intense. Global models continue to indicate the drying trend with more favorable conditions for deep convection to the north of the Amazon. The direct effect of the "friagem" is not expected to reach Santarém. Prepared by: Pedro Silva Dias Forecast for July 28th Yesterday forecast for today was OK. The regular development of the convective clouds along the Tapajos river and the decrease of widespread convection to the E/SE of Santarém were verified as well as the tendency for trajectories arriving in the Santarém region from the SE. The trades are weaker now after the "friagem" to the west (temperature in W/SW Amazon didn't rise above 22C (Leticia in Colombia)! Effects of the "friagem" are evident just west of Manaus with low stratiform clouds and temperature in the low 20's , compared to 30"s in Manaus and east Amazon. Contrary to the previous days, the model predicts the beginning of the development of convective precipitation along the Amazon River in the Santarém area, extending southward along the Tapajós for a relatively short distance (just south of Belterra) at 15 UTC. This different evolution seems to be a result of the weak trades and the confluence of the Tapajós and Amazon breeze in Santarém. The model also predicts reduced precipitation in the afternoon, compared to the previous days (also well predicted yesterday). Chances for heavier precipitation remain to the north of the Amazon where the instability indices are much more favorable than to the south. Forecast for July 29th The regional model indicates less precipitation associated with the river breeze at 15Z along the Tapajós river than on the previous day. A different pattern is also indicated with initial development of more active cells along the left margin, followed by the right margin (this is another one to be verified tomorrow!!!). These changes seem to be a response to the more southerly flow predicted for the 29th during most of the day. More significant precipitation is expected after 18Z (mostly along the Tapajós and Amazon (1- 2mm/3hr in an area average) but some precipitation to the east as well). Instability indices are more favorable for deep convection to the north of the Amazon. The indices are generally less favorable for convective development than on the 28th. Thus, a general drying is expected in the neighborhood of Santarém. Trajectories in the mixed layer are expected to be from the SE. Depth of the mixed layer is expected to reach 900-1200m above the surface and deeper to the SE. Forecast for July 29th The prevailing convective clouds along the Tapajós river (yesterday forecast) was verified, with widespread local showers east of the river up to the Santarém-Cuiabá road (BR163). The satellite images indicate less intense convective clouds on the left margin of the Tapajós at 1415Z, compared to the convective activity on the right margin. However, due to power interruption at USP, we don't have later images for verification of the later evolution. Minimum temperature at Tabatinga (extreme W of Amazon in Brazil) reached 16.5C due to the "friagem". Widespread shallow clouds are observed in the western Amazon, also associated with the "friagem". Local circulation associated with the river breeze in clearly identified in the pilot balloon data and sodar in view of the weak trades. Regional model predicts small precipitation accumulation (between 1-2 mm/3 hr in an area average sense) beginning along the river and few isolated cells to the SE of Santarém (instability indices are barely favorable for convective growth). Mixed layer is predicted to reach about 900-1100 m above surface, increasing to the east. Trajectories in the mixed layer show a SE component. Forecast for July 30th Due to the power failure in SP, the 00Z forecast is not available at the homepage and therefore there is no model guidance for the convective cloud development in the afternoon of the 30th. The regional model forecast which started from 12Z on the 28th indicates the regular diurnal evolution of convection but instability indices are less favorable than on previous days. Thus, more isolated cells are predicted to evolve during the day east of the Tapajós. Trajectories return to the E/NE during the day. Mixed layer remains at 900-1100m above the surface. Extended range forecast: The major feature indicated by the global models is the intensification of the trades on the 31th July to the 1st and 2nd of August. As a result, instability lines along the coast are expected to return. Although the basin scale conditions are not favorable for convection ( the models continue to indicate the drying trend with prevailing condition for convective clouds to the north of the Amazon), some of these lines may eventually reach the Santarém region during the night/early morning. No significant forcing from higher latitudes is expected in the next week. Prepared by Pedro and Maria Silva Dias Forecast for July 30th Clear skies this morning in Santarem. Most of the Amazon region west of 60 W has fog/stratus this morning with southerly flow and dew points of about 17 to 18 C. Santarém is east of this area with dew points of 23C (lower than a few days ago when aproximately 25-26C). Fog was observed in river valleys. The regional model shows again 1-2 mm for today precipitation mostly as local showers from Cumulus congestus. Trade winds will be weak again today with a good chance of reversal of winds very close to the river in the early afternoon. Mixed layer heights are forecast to reach 1000-1100 m and air parcel trajectories remain from the SE. Forecast for July 31st Global models maintain the forecast of trade wind picking up again after the early morning of the 31th and upper level winds also increasing. With the enhanced vertical wind shear the coastal convective lines may form again with a good chance of propagation, and may reach the Santarem area in the early morning of the 1 st of August (probably as a weak area of convective activity). Extended range forecast: The extended range forecast shows several easterly waves in the Tropical Atlantic reaching the northern coast of Brazil near Belem, maintaining a low level 700 hPa jet. The trade winds are forecast to be strong at least up to the 3 rd of August. Most of the significant instability indices are to the North of So. America. With this outlook, local showers may develop during the day in response to surface heating and local circulation, coastal squall lines may form and propagate, and winds are forecast to have a more easterly direction. Prepared by Pedro and Maria Silva Dias Forecast for July 31 Very localized showers were seen yesterday afternoon in the Santarem area. Mixed layer heights reached 800 m above sea level in Belterra. Late at night a deep convective cell was observed south of the Flona area with lots of lightnning, but moved quickly west and dissipated. Remnants of a coastal squall line reached the Santarém region (north of the Amazon river) during the early morning. Initial development of precipitation should occur along the Tapajós but relatively widespread convection is expected to be observed earlier today (by 15 UTC). The regional model indicates the organization of several convective lines in the afternoon (N/S orientation) and therefore precipitation is predicted to occur on regular intervals in the late afternoon/early evening (18-21Z). Trajectories during the day predominatly from the E. Deeper mixed layer is predicted for today (1000 m) at 18-21Z. Forecast of August 1st Model indicates more organized precipitation during the night/early morning than on the previous day, as a result of coastal lines which should reach Santarém at this time. Preference for N/S oriented propagating precipitation bands is also favored tomorrow afternoon/early evening. Trajectories change to a NE/E origin. Mixed layer heights are expected to reach 90- 1000 m at 18-21Z than the 1st (probably a result of the increased precipitation). Extended Forecast Global models indicate dry conditions in the Amazon except the northern part of the basin. But the prediction of easterly waves activity has been consistent. The more favorable phase for convection reaches Santarém on the afternoon of the 01st and another favorable phase on the 3rd and 5th (i.e., a succession of easterly waves of shorter period). During these days the trades are expected to be stronger. Thus, slightly weaker trades are expected on the 4th of August. These waves can help the organization of the coastal lines and promote a favorable environment for their propagation. Prepared by Pedro and Maria Silva Dias Forecast for August 1 A coastal squall line propagated from the coast and reached Santarem early in the morning today as a succession of norht-south oriented lines of congestus. The sounding at Belterra yesterday early afternoon showed a double mixed layer structure, the first from the top of a superadiabatic layer at 300 m ASL (surface is at 176 m ASL) to 750 m with potencial temperature of 301.9 K and a sharp transition to 303.0 K kept constant up to 1170 m. Winds were from the SE up to 300 m and then gradually shfted to E and NE. For today the regional model forecast calls for scattered showers in the afternoon, mostly in the eastern side of the Tapajos river, getting more organized late in the day with propagating north-south convective lines. Strong 700 hPa wind speeds close to Belem still indicate good conditions for propagating squall lines reaching Belem early in the morning. Trajectories today are forecast with a ENE orientation. Forecast for August 2 Regional model indicates similar conditions for tomorrow. Early morning convection from the coastal propagating lines, followed by a clearing of skies, local showers in the afternoon and more organized systems later in the night. The forecast maintains conditions for propagation of convective lines. Instability indices are forecast to increase by 0Z on the 2nd and then decrease again. Extended forecast The global model indicates that very low instability indices at the northern coast from the 3rd August onwards. Precipitation is forecast very low during the 3rd and 4th increasing on the 5th where a large area of precipitation is seen to move from the coast to southwest and then westward into Manaus on the 6th. Trade winds of moderate intensity (4 - 5 m/s) are seen throughout this period. Prepared by Pedro and Maria Silva Dias Forecast for August 2 After a few days without operational soundings they are back today showing very dry conditions in southern Amazon with a strong 700 hPa subsidence inversion. Manaus and Belem show a weak inversion; satellite images indicate suppression of convection mostly to the south of Manaus. A small convective line formed yesterday evening to the south of the Marajo Island and propagated to southwest reaching Santarem this morning as a single well developed cell. Skies were overcast up to 9 LT and then cleared. The regional model shows small amounts of precipitation, isolated scattered showers. For the Santarem area, most of the showers are seen in the eastern side of the Tapajos and to the north of the Amazon river were topogrphy reaches 350 m ASL. Trajectories for this afternoon are from the NE and mixed layer heights remain around 1000 m. Forecast for August 3 Winds at 700 hPa are weaker today and the regional model forecasts same condition for tomorrow. Accordingly, the model produces only small convective lines for this evening and early morning around Santarem Trade winds are forecast from SE at about 4 m/s and mixed layer heights remain around 1000 m. Shallow cumulus evolving into a few congestus in early afternoon are maintained. Extended forecast Dry condtions persist for the region so that only local showers are expected. The global model maintains an increase in the 700 hPa winds at the northern coast for the 4th and 5 th with the propagation of a convective area. Subsidence is maintanined in southern Amazon and specifically in Southeastern state of Para where fires are being reported to have increased in the last couple of days. Trade winds are forecast to be from E - SE in the extended range forecast, thus advecting smoke to the northwestern area which includes Santarem, initially very diluted. See the homepage http://www.cptec.inpe.br/products/queimadas/queimap.html for a monitoring of fires. Weather products may be found in http://www.master.iag.usp.br Prepared by Pedro and Maria Silva Dias Weather conditions today August 3 Belterra sounding showed mixed layer heights this afternoon of about 1200 m ASL with a 700 hPa subsidence inversion beggining to appear as compared to yesterday. Accordingly, convection was highly suppressed today with cloud strees of cumulus humilis; trade winds were from the ESE with 4-5 m/s. Forecast for August 4 The regional model indicates supressed conditions for convection, mixed layer heights at around 1100 m. Trajectories reaching the surface at Santarem are forecast to be in a subsidence motion initially from SE to NW at about 1.2 km and then changin to NE to SW at lower levels. There are no favorable conditions for propagating squall lines. Extended forecast The global model run today shows a change from the previous runs in that the wind speed at 700 hPa is weaker up to August 7 indicating unfavorable conditions for propagating squall lines. The model maintains subsidence in the Amazon region including Santarem thus indicating suppressed convection. The model indicates less subsidence after August 6. Moderate trades of 4-5 m/s are forecast for this period. Weather conditions today August 5 The inversion at 700 hPa as strengthned and can be seen as far north as Belem this morning. Most of Central Brazil and the Amazon region have clear skies with shallow cumuli. In the Santarem area, cumuli are more developed in the Amazon river margins, very sparce in the Tapajos eastern side and absent in the western side, and also over the rivers. We measured cooler water temperature in the Amazon river than in the Tapajos river, thus stronger daytime circulations are really expected along the Amazon shore. Low level winds (inside the mixes layer) today at Belterra were of 5-6 m/s from SE . Mixed layer heights during the 18Z sounding (14 local time) reached 1700 m today. Forecast for August 6 The regional model forecast for tomorrw morning shows low level winds from the NE turning into E and SE during the afternonn and evening with 5 m/s. Early afternoon trajectories reaching Santarem have a NE/SW orientation. Mixed layer heigths should be between around 1600-1900 m on the east side of the Tapajos reiver. Unfavorable conditions for deep convection are maintained as well as for propagating coastal systems. Extended forecast The global model maintains similar conditions as today and tomorrow up to Tuesday, the 7th, at least. There is an indication of increasing 700 HPa winds at the northern coast by Wednesday associated to a propagating Atlantic easterly wave. We will be watching this system as a possible source of change in the condtions around the area. The haze from fires is already well established in Central Brazil and reaching the Amazon Basin; no precipitation is forecast for the next week in Central Brazil thus the haze is expected to become more dense in the next few days, reaching also the Santarem region. Weather conditions today August 6 Convection is still very supressed today except to the north of the Amazon river were topography reaches 350 m and a few congestus have developed this afternoon. Mixed layer heights today at Belterra are about 1400 m, winds at the boundary layer are a bit stronger than yesterday at 6 m/s from SE. From the top of the mixed layer to 700 hPa are from the E between 7 and 11 m/s. Last night, coastal convection could be seen only to the north of the Marajo Island propagating due west during the early morning hours, well to the north of the Santarem region. Forecast for August 7 No change for tomorrow in the overall atmospheric structure. The regional model maintains convection at the coast north of the Marajo Island for the evening. For the Santarem region, suppresed convection and trajectories from ESE for tomorrow. Extended range forecast The global CPTEC model maintains the arrival of a convective region at the Northern coast by Wednesday, the 8th,asociated to an easterly wave, with an increase in the 700 hPa wind speeds. A possible effect would be a weakening of the subsidence inversion and the development of coastal convection around Belem. After that, a series of convective areas in the Atlantic are seen to propagate maintaining the possibility of coastal convection eventually with some propagation into the Santarem area early in the morning. The NCEP global model has a similar forecast except that the core of stronger convection is displaced a few hundreds of km to the north, barely touching the northren coast. We will keep watching the Atlantic easterly wave evolution in the next few days as it appears to be the only system which may possibly affect the area. Weather conditions today August 7 No noctunal propagating systems has been seen in the Santarem region.The 18 Z sounding in Belterra today shows a deeper mixed layer reaching 1900 m; mixed layer winds are from SE around 11 m/s increasing to 12- 15 m/s above it still from the SE. As in the previous days, only small cumuli are seen in the satellite images of the Santarem area, convection is seen at the northern coast over the Guianas with westward propagation. The sounding this morning in Belem still shows a 700 hPa inversion and a stronger one at 550 hPa. These inversions are weaker in the 12 Z Manaus sounding. Forecast for August 8 The approaching easterly wave mentioned yesterday is forecast to produce little effect on convection at the northern coast thus no major change is forecast. Cloud streets of cumulus humilis are still forecast and the SE trades are maintained. Extended range forecast Both NCEP and CPTEC now forecast easterly waves in the tropical Atlantic for the next 3-4 days but without much effect on the northern coast convective activity up to the 10 th. Weather conditions today August 8 Convection is a more active today with a few cumulus congestus forming in the Santarem area and a few showers observed this afternoon. Early in the morning the southeast end of a weak line, formed yesterday night, north of the Marajo Island passed the area. Mixed layer heights at Belterra are lower today at 1200 m with winds from ESE at 5 m/s turning to SE above the mixed layer. Last night the nocturnal inversion was 120 m deep. The sounding in Belem still shows the inversions at 700 hPa and 500 hPa but weaker than yesterday. CAPE has also increased from yesterday morning to today and the layer of strong winds is a now reaching 700 hPa. This conditons would indicate an incresing possbility of convecion closer to Belem this evening, contrary to the previous days. Forecast for August 9 The regional model has more convection for tomorrow than in the forecasts of the previous days. A weakly organized convective area is seen SW of Belem late at night propagating to WSW throughout the early morning. This may produce some cloudiness in the Santarem area early in the morning. Trajectories reaching Santarem tomorrow afternoon are forecast wih an ESE orientation. Mixed layer heights forecast for tomorrow are between 900-1200 m. The model also forecast more convective activity for the afternoon than in previous days. A few showers should be expected. Extended range forecast NCEP and CPTEC have different forecasts for the next few days along the northern coast. NCEP keeps all convection well away from the coast over the ocean up to the 12th. CPTEC forecasts increased convection at the coast and inland for the 10 onwards up to the end of the period. CPTEC is consistent with the previous forecast. Actually it appears that today is already different from the previous days and perhaps the CPTEC forecast is late with the change but still more coherent with today. The increase in convection around the Belem area means more overcast skies early in the morning in Santarem dissipating during the morning. Afternoon with shallow cumulus and just a few Cumulus congestus are expected. Weather conditions for August 9 Early morning had clear skies. During the afternoon small cumuli and a few showers were seen in the area. A Coastal line formed during the afternoon to the east of Belem and propagated troughout the region reaching Santarem early this morning. The subsidence inversion seen in the previous days at 700 hPa was seen in tha Manaus sounding at about 620 hPa and was weaker in Belem. The WSW end of the Atlantic ITCZ was seen over Belem. Forecast for August 10 The regional model forecast for August 10, Friday, calls for the development of local circulation and associated cloudiness specially to the north of the Amazon river and along the eastern shore of the Tapajos. Mixed layer heights are still forecast around 1000m and trajectories reaching Santarem in the afternoon are from the ESE in agreement with the CSU Lagrangian Particle model. The regional model also forecasts for tonight the propagation of a weak line from the northern coast to the Santarem area. Extended forecast The CPTEC model correctly simulated the increased chance of precipitation at the coast. It maintains the same conditions for the next days. So the effect expected in Santarem is more cloudiness early in the morning with a few showers, a clearing of the skies and cumulus clouds forming late in the morning. With a weak subsidence inversion, a few Cumulus Congestus should develop and a few showers expected. Weather conditions for August 10 The nocturnal inversion in Belterra was 170 m deep last night. The unexpected recovery of a small convective cell this morning to the NE of Santarem lead to a large isolated convective system that passed north of Santarem before noon. During the afternoon, small cumuli formed east and west of the Tapajos, very suppressed on the west side; a shower hit Belterra at about 4 PM. The mixed layer at 2 PM reached 1600 m ASL with winds from SE of about 3-5 m/s in the mixed layer, turning to NNE with 7 m/s above it. At 700 hPa winds were from the E at 9 m/s. the 700 hPa subsidence inversion is still identified in the Belterra sounding, very weak this morning in Belem, and absent from the Manaus sounding. The 550 hPa inversion is still present in all three soundings. Forecast for August 11 The regional model forecasts convection for the afternoon of Friday at the northern coast (verified in the satellite images) and has this convection propagating inland reaching Santarem in the early morning. The afternoon showers are forecast to produce more rain than in the previous days. Trajectories and the CSU LPDM show air parcels with the same general movement as in previous days, i.e., from ESE. Extended range forecast The CPTEC and NCEP keep some convective activity at the northern coast in the following days up to 14th. Thus nocturnal systems continue to be expected reaching Santarem in the early morning hours. The subsidence is forecast to remain constant throughout this forecast cycle. Weather conditions for August 12 Again a day with cloud streets of shallow cumuli during the morning turning to a few congestus in the afternoon. Where the eastern shore of the Tapajos reaches the Amazon river, close to Santarem, the cumulus congestus are more abundant early this afternoon. Yesterday, Saturday, a well defined squall line went over Santarem early in the morning. No such system was seen today. The 700 hPa inversion is not seen today but a new one is seen at 600 hPa at Manaus, Belem and Belterra. The 500 hPa i nversion is still present also. Upper level winds are from the west and mid to upper level cloudiness over the southern half of the Para' state is organized in north-south cloud strees moving west. Forecast for August 13 The regional model forecast shows weak convection during the night and early Monday morning for Santarem. Reduced subsidence at 500 hPa turning into upward motion during August 13 is also seen with an increase of wind speed at 850 and 700 hPa and a possibility for squall lines from the northern coast during the afternoon reaching Santarem early on the 14th. The daytime evolution of convection on Monday is forecast to maintain similar conditions as in previous days. Isolated showers should be expected in the afternoon. The CPTEC fire homepage shows that in the last 3 days more than 400 foci of fires have been identified in NOAA 14 images for the state of Para, mainly in its southern half, so that SE winds are expected to increase the haze in the Santarem area. Extended range forecast The easterly wave reaching the northern coast during Monday evening will keep stronger 700 hPa winds on the 14th and diminishing on the 15 th, acording to the CPTEC forecast. The model also forecasts an increase in the trade winds speed on the 14th and a more ENE direction. Weather conditions for August 13 Last night convection developed over the Amazon river and rainfall was observed in Belterra up to 6 AM, basically from Cumulus congestus. Clouds moved west and dissipated early in the morning and clear skies dominated until 10:30 AM local time when the small cumulus started to form. The mixed layer in the 2 PM Belterra sounding reached only 500 m today with average wind speeds of 4 m/s from ENE. The Manaus sounding is more convective today and does not show the inversions of the previous days. Convection was already developing in the northern coast over Belem and east of Belem by early afternoon. Forecast for August 14 The convection in the northern coast seen this afternoon is forecast to propagate to SW during the night as a line of weak convective cells. Tomorrow morning skies may have some remains of the norturnal system but clearing is expected with developing of the mixed layer to 700 - 900 m. The trade winds are forecast to be of about the same intensity as today. Extended range forecast The global models have decreased the intensity of the winds associated to the incoming easterly wave and so no change is expected for the next few days; convection along the northern coast may develop since the inversion is no longer active, but propagation although expected should not be enhanced.