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J.N. Kagenyi Senior Meteorologist RS/GIS IMTR-NAIROBI SWFDP NOV.2012.

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Presentation on theme: "J.N. Kagenyi Senior Meteorologist RS/GIS IMTR-NAIROBI SWFDP NOV.2012."— Presentation transcript:

1 J.N. Kagenyi Senior Meteorologist RS/GIS IMTR-NAIROBI SWFDP NOV.2012

2  Synoptic (MDD)  Satellite (MSG Channels, RGB products) MPEF, SAF Products e.g. (Now casting SAF), MODIS products, jason etc  NWP models  different spatial and temporal resolutions (UK Models (3,to 0.5 deg), WAFs,ECMWF models, Local models (LAM, regional models) and many more  Diagnostic models (manual plots and analyses, development and forecast)  Radar data for nowcasting,  Climatology (seasonal information to help with shift from normal) 2

3  Integrate all data in a workstation  Equipping the weather person with power of information  Role for experienced Forecaster is to obtain optimum information from ALL the available data to make Reliable Forecast  Capacity to handle all this data is the subject of your presence Here! 3

4  Assumptions  all participants have access of Synergie system back home.  Availability of Near Real Time (NRT) data for this exercise.  Step 1. What season are we? Rainy season! Hence certainty of S/WX case is more certain  Step 2. display a VIS Image if daytime otherwise ch4 (3.9) or RGB Convection(10-9,9-4,9-0) at night time, to identify location of any convection by water clouds 4

5 5 Several convective cells at different stages of development

6  Use WV 6.2 and 7.3 microns to identify potential areas with enough moisture to support further development (Deep column)  White areas are moist and cold, dark or grey areas are low in WV and warmer.  Upper level moisture from WV5 (6.2)  Medium Level moisture from WV6 (7.3) 6

7 7 1.Convective cells are within the high density water vapour. 2.They exist in convergence zone.region 3.Moisture supply is high 4.Time is 12:12 pm 5.Further development possible likely

8 Sufficient moisture at mid levels Question Is there enough Thermodyna mic (Pressure Field) convergence at lower levels and Upper air diffluence (wind data or Animations) to generate deep convection? 8

9  You may animate Vis or IR, RGB consecutive images for the last 15,30,45,60 minutes  This will answer the two questions:  Is convection increasing or decaying?  What direction are systems leading?  How fast is the system developing?  Channel 3(1.6): good for daytime as reflectance reduces for developing severe storms and brighteness for decaying storms  At night use night time microphysics RGB (10- 9,9-4,9-0) or 5-6,9-4,5i air-mass) 9

10  Animate=2003 observation. Animate  It is evidence on this animation that between 8-12:30  the region around southern lake Victorian and land east of the lake developed from shallow convection, white reflectance on ch3 to deep convection of large ice crystals (low reflectance=grey) similarly over Kisumu and Western Nyanza of Kenya.  use Ch9 to confirms temp changes. 10

11 11 Deep red indicates very cold large ice clouds. The Yellow brown are areas with small ice and water clouds at stage of development see over lake Tanganyika. Cyan is cloud free and warm Deep Blue is warm water body

12 12 Deep dirty brown indicates very cold large ice clouds. The yellow areas are clouds with small ice and water clouds at stage of development- Super-cooled (- 33 deg) clouds, see over lake Tanganyika. Cyan is cloud free and warm Deep Blue is warm water body. Thin Cirrus clouds appear dark brown

13  View reported synoptic data for synoptic hours.  Confirm from dry bulb and web bulb data for drying or increase in moisture from depression values or differences of ( T a -T d )  You may use conditional plotting of Synergy tools.  Area whose( T a -T d ) <=1 Moist or cloudy  Areas whose Ta-Td =>8 dry air conditions 13

14 14 Scarce data stations requires to be complement ed with Satellite data

15 15 1.Current Wind analysis suggests a convergence zone as shown 2.Position of deep convection is supported by convergence of the winds 3.Moist Easterly winds supply moisture

16 16 1.Dry cold air-mass from Southern Tip of Africa. 2.This appears to be under St Hellena high pressure ridge cell (descending air). supports synoptic p/gradient 3.Moisture: dry bulb 30 o C wet bulb -4 o C. (Dry air)

17  Deep convection goes beyond medium and upper tropopause hence  Any weather feature that causes WV5-WV6 >0 generates TS and Heavy Showers/ rain  Solar radiation & Mechanical lifting (wind field convergence zone or orographic lifting) contribute to development of severe weather. 17

18 18 Dark is negative White is positive or almost equal to zero Analysis for Deep convection

19 19 Synergie Under tool important for And comparison WV5 under Airmass RGB

20 20 Areas of deep convection in Red

21 21 To detect dry and moist air sources

22 22 Positions of Jetstreams affects Weather in their region of influence for instance creation of strong outflows at the tropopause level. The Onset of a season could be associated with the intensity and the position of Jetstreams E g. EAST Africa Low Level jet (July –September)

23 23 1.Satellite imagery confirms the identification of convergence zone by a belt of Cloud clusters. 2. Image analysis gives colours that depict the type of system and the stage of development

24  Areas of low level convergence  Corresponds with areas of deep clouds  Causing High MPE values 24

25 25 Streamlines on 200 hPa BLUE 850 hPa (RED) and IR 10.8 on background.24 hrs shift. Notice the position of Outflow on 200

26 26

27 27 NWP data and the Synoptic data report. 1.Gives great harmony on data analysis to forecasters. and In particular when NWP replicates the weather as observed on Satellite The Belt of convergence on NWP wind analysis on 850 hPa identifies areas of expected Severe Weather. Meridional Arm of ITCZ is denoted red The Identification of pressure features provides tools of decision making in Wx fcasting.

28 28 Will your forecast give better Results than this estimate

29 29

30 30 Active ITCZ zone is clearly defined on this mid level signal map. DRC and neighboring countries, Botswana Zambia, are wet. Seasonally the Sothern African countries Except Namibia and SA are experiencing the Onset of rains.

31 31 Ascent analysis : 1.Very Unstable at lower levels. 2.Generally moist atmosphere but dry at 450 hpa 3.Easterly Wind pattern conducive for afternoon WX activities Fcast: Showers and T/S over several places over Nairobi and Highlands East. Lake basin: Heavy TS/Showers over most places. Flooding Alert! In Lake region

32  Exercise: Create a forecast for Severe WX for your regions: 5 slides  Present to us.  Use Synergie  Form groups of 4  Use 20 Minutes: 32

33  Kwaheri na ASANTE 33

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