March, 16 - 2014

Summary

1. General weather condition ................................................................................................... 2

2. Synoptic Scale ........................................................................................................................ 2

3. Radar images ......................................................................................................................... 7

4. Other instruments ................................................................................................................. 8

1. General weather condition

In March 16 the maximum and minimum temperatures observed in Manacapuru were 31.6°C

and 24.2°C, respectively, registered by INMET weather station. The temperatures, in Manaus,

ranged between 25.2°C and 31.8°C. Through the analysis of synoptic conditions for March 16,

Atlantic Subtropical High centered over eastern 30°W was found. An Extratropical Cyclone acts

in Argentine, centered around 44°S/60°W. The ITCZ main branch over Atlantic Ocean acts

betweens 01°N/02°N. It’s possible to observe winds blowing from east/northeast at 850 hPa

level and, at high levels it’s observed the cyclonic circulation over Manaus region. CAPE

decreased from 889 J/Kg to 548 J/Kg around 0000 and 1200 UTC. CINE values increased from

19 to 50 between 0000 and 1200 UTC. S-band and X-band radar images show some local

convective rain cells, moving from northeast over Manacapuru-T3 site were observed, with

reflectivity (rain rate) values greater than 30 dBZ (~5 mm/hr). In general, no significant

precipitation systems were observed a long of the day over Manaus region. The satellite

images show clear sky conditions associated with subsidence over Manaus region. This

subsidence is resultant of the cyclonic circulation over the region.

2. Synoptic Scale

Figure 2.1 shows synoptic conditions for March 16 at a) surface, b) 850 hPa and c) 250 hPa

levels at 1800 UTC. Atlantic Subtropical High centered on eastern 30°W. In Figure 2.1a a

stationary front over the Atlantic Ocean southeastern of the 39°S/40°W was observed. One

extratropical cyclone acts over Argentine centered around 44°S/60°W. The ITCZ main branch

over Atlantic Ocean acts betweens 01°N/02°N. It’s possible to observe winds blowing from

east/northeast at the 850 hPa level and, at high levels a cyclonic circulation over Manaus

region was observed.

a)

b)

c)

Figure 2.1: Synoptic conditions for March 16 on a) surface, b) 850 hPa and c) 250 hPa levels.

Source: CPTEC/INPE.

Figure 2.2 shows satellite images (from IR channel), at (a) 1200 and (b) 1800 UTC valid for

March 16. It was observed a clear sky conditions associated with subsidence over Manaus

region. This subsidence is resultant of cyclonic circulation over the region.

a)

b)

Figure 2.2 – Channel 4-IR GOES-13 images for (a) 1200 and (b) 1800 UTC valid for March 16.

Source: DSA/INPE.

Figure 2.3 shows thermodynamic profiles (by Skew-T diagram) for Ponta Pelada site at (a) 0000

and (b) 1200 UTC (March 16). CAPE decreased from 889 J/Kg to 548 J/Kg around 0000 and

1200 UTC. CINE values increased from 19 to 50 between 0000 and 1200 UTC.

a)

b)

Figure 2.3: Thermodynamic profiles for Ponta Pelada site at a) 0000 and b) 1200 UTC. Source:

Master/IAG/USP.

3. Radar images

Figure 3.1 shows S-band and X-band radar images (CAPPI-2km) from SIPAM and CHUVA

Project, located at Manaus and Manacapuru cities, for March 16 at a) 2000, b) 2100 UTC, c)

1950 and d) 2000 UTC, respectively. Some local convective rain cells, moving from northeast

over Manacapuru-T3 site were observed, with reflectivity (rain rate) values greater than 30

dBZ (~5 mm/hr). In general, no significant precipitation systems were observed a long of the

day over Manaus region.

a) b)

c) d)

Figure 3.1 – SIPAM (S-band) and CHUVA (X-band) radars reflectivity (dBZ)/rain rate (mm/hr)

from CAPPI-2km product, for March 16 at a) 2000, b) 2100 UTC, c) 1950 and d) 2000 UTC.

4. Other instruments

Figure 4.1, shows the Micro Rain Radar (MRR) radar reflectivity and Liquid Water Content

(LWC) time series from 0000 UTC to 2400 UTC. No precipitation were observed during the

referenced period at Manacapuru site.

a)

d)

Figure 4.1 - MRR measurements of Average of the Radar reflectivity (a) and Liquid Water

Content (b) for March 16, from 0000 to 2400 UTC, measured at Manacapuru.