NEM 2015 Analysis and Forecast

Page dedicated for analysis and forecast for NEM 2015 

94 thoughts on “NEM 2015 Analysis and Forecast

  1. NEM-season’s QBOONI rule:
    Quite opposite for NEM rains when compared to SWM’s QBOONI.
    Means if QBO is in decreasing trend with respect to ONI index’s increasing trend (means if both moving in opposite directions/inversely proportional) during NEM-season, then NEM will be normal/excess and vice-versa.

    Hope for favorable NEM-QBOONI:
    At present QBO is increasing trend along with ONI. As ONI won’t decrease by the end of NEM-2015, then we expect QBO again start decreasing by September/October at least for good comprehensive NEM-2015 rains in the order of 1997-NEM season. In order to receive at least normal NEM-2015 (if not excess) at least November QBO must start decrease (as there is no hope in ONI decrease till spring -2016).

    1. SWM- season’s QBOONI rule:
    When QBO is in decreasing trend with respect to ONI index’s increasing trend (means if both moving in opposite directions/inversely proportional) during SWM-season, then SWM will record less than normal and vice-versa.

    2. QBOONI rule utilizes only 2 parameters, QBO & ONI indexes (both can foreseen in accurate in advance).

    3. With this powerful QBOONI rule, one can ignore all parameters like MJO, SOI, IOD, NAO, AO, etc. Thus lot of confusion can be avoided. Under favorable QBOONI rule, dynamics will orient in such way to give bountiful rains during NEM/SWM seasons.

    4. We can get clear equation in Elnino/Lanina years. But ENSO-neutral years also can get clear cut correlation most of the times.

      • actually +ve QBO (westerly phase) has half amplitude to -ve QBO (easterly phase). This means +ve QBO can not go beyond +16.0 (as -ve QBO can not go below -32.0 as per the past data, these values may change in future after hundreds of years).

        Accordingly at present QBO is at +2.0 and so by august it must reach maximam value of +15/+16 in order to start decreasing from September to favor NEM-2015. So hope for the best.

        1. In order to become 2016 as Lanina, QBO must start decrease again.
        2. The timely decrease in QBO by the time of NEM onset time will decide NEM fate.
        3. Even if QBO stabilizes around certain value (without any ups & downs) during October to December with respect to increase in ONI can give normal NEM-2015.

  2. Negative NAO is good for NEM. As per forecast it will stay neutral till October and may change to negative during OND period.

      • yes, definitive (persistent) -ve values in NAO, AO & AAO is indicative of strong siberean high (SH), which is well documented in the literature.

        But strong SH doesn’t give good NEM if there is no proper ENSO & IOD signal.

      • This time north India will get strong and more numbers of WDs beginning from November. Will increase in frequency and strength in WD help in strengthening of SH.

      • is it not positive iod from august to october is crucial for NEM or is this only applicable for elnino year…
        the reason i have thsi doubt is because you were saying -IOD is good for NEM

      • Strong el nino with positive IOD gives good NEM but negative IOD is always good for NEM. Negative IOD( BOB warmer than AS) results in good number of systems in BOB during NEM.

      • el nino is associated with positive iod whereas la nina is associated with negative iod. Currently we are having strong el nino so IOD may become positive in coming months.

      • In general
        1. There is high chance for 2 to 3 BOB-systems to strike TN with neutral IOD couples with Elnino (classical/non-classical can be debated later). so NEM-rainfall can reach normal.

        2. There is low chance for BOB-systems to stike TN with -ve/neutral IOD couples with Lanina (classical/non-classical can be debated later). so NEM-rainfall can end below normal.

      • but el nino never happens with negative iod. Negative IOD is the killer of el nino.

      • yes exactly. Even in 1965 IOD turned neutral by the time Elnino onset taken place.

      • this snow cover is like double edge sword. but the timing of snow decides the fate of ENSO when coupled with ONI.

        For example:
        1. winter with good snow early (which ends early to set early summer), which doesn’t disturb land-heat low timing can set the good SWM (in the absence of ONI, it leads to lanina).

        2. winter with good snow lately (which ends late to set early late, which disturbs land-heat low timing can set the bad SWM (in the absence of ONI, it leads to Elnino)

      • -NAO is good for negative IOD development and we know negative IOD is good for NEM.

      • We have already discussed about NAO and IOd relationship using your thermohaline circulation diagram.
        Positive NAo helps in positive IOD development and vice versa.

      • arctic ice cover reached lowest due to Elnino. so expecting strong high-pressure forming around arctic, which can result severe winter condition by fall (early winter).

  3. Guest11k,
    So we can expect early starting and early finishing of WD-related snowfall this coming winter to make SWM-2016 seasonal LOW as early possible to ignite timely powerful SWM-2016 express.

  4. Central indian ocean may remain warm through out this year. It can affect upcoming NEM negatively.

  5. 1914


    Jan – 26.9

    Feb – 0.0

    Mar – 0.0

    Apr – 52.1

    May – 0.3

    Jun – 16.3

    Jul – 66.0

    Aug – 239.0

    Sep – 173.7

    Oct – 488.2

    Nov – 297.9

    Dec – 78.0


    Total – 1438.40 mm

    Courtesy: Pradeep John

  6. The only difference between this year and 1914 is that during 1914 IOD was 0.3 during SO period and -0.2 during ND period whereas as per IOD forecast for 2015, IOD may oscillate between (0.5-0.2) during SO period and may come down to 0.1 during ND period. Rest of the values( QBO, ONI index) is very similar to 1914. SO we can expect normal NEM this year and we may get less number of cyclones but more easterlies during coming NEM season.

  7. This year will be similar to 1914. Already few similarities emerging. This year June rainfall( 21 mm) is similar to June 1914( 16mm). Good rainfall in April 1914 and this year. If IOD changes to positive in coming August, southern peninsula tend to get good rainfall ( Chennai got good rainfall during AS period of 1914

  8. ONI index peaked around +2.5 during NDJ period of 1877.

    QBO was constant around +10 during OND in 1877.

    Positive iod emerged in August and peaked in September. It was neutral during JJ period.

    Forecast for 2015.

    ONI will peak around +2.5 during NDJ period.

    QBo will be constant around +10 during OND.

    Positive IOD may emerge in August and may peak in September. It was neutral during June and July.

  9. 1877

    Jan – 0.3
    Feb – 0.0
    Mar – 0.8
    Apr – 0.0
    May – 0.0
    Jun – 59.9
    Jul – 31.0
    Aug – 63.2
    Sep – 80.0
    Oct – 217.4
    Nov – 539.8
    Dec – 148.8

  10. Coming NEM season cyclogenesis will be happening in SC/SE Arabian sea and near Kerala coast. BOB may stay quiet this time.

  11. System is possible for Chennai coming NEM provided IOD stays neutral.

    In 1888 which was a strong el nino year with neutral IOD, Cat 3 cyclone made direct landfall over Chennai.

  12. 2005 – 2108 mm

    1997 – 1570 mm

    1996 – 1260 mm

    1994 – 1184 mm

    1976 – 1191 mm

    1969 – 1235 mm

    1960 – 1227 mm

    1946 – 1582 mm

    1944 – 1183 mm

    1943 – 1378 mm

    1941 – 1164 mm

    1930 – 1398 mm

    1925 – 1198 mm

    1922 – 1292 mm

    1920 – 1310 mm

    1918 – 1275 mm

    1913 – 1417 mm

    1903 – 1146 mm

    1898 – 1173 mm

    1896 – 1344 mm

    1887 – 1267 mm

    1884 – 1598 mm

    1883 – 1219 mm

    1872 – 1357 mm

    1857 – 1132 mm

    1853 – 1243 mm

    1847 – 1451 mm

    1846 – 1445 mm

    1822 – 1149 mm

    1818 – 1303 mm

    1817 – 1273 mm

    1815 – 1124 mm

  13. Excess NEM years for TN

    1877 – 665 mm
    1880 – 637 mm
    1884 – 859 mm
    1887 – 689 mm
    1884 – 584 mm
    1896 – 615 mm
    1898 – 678 mm
    1902 – 639 mm
    1913 – 612 mm
    1914 – 584 mm
    1920 – 613 mm
    1922 – 651 mm
    1925 – 587 mm
    1930 – 705 mm
    1931 – 657 mm
    1940 – 609 mm
    1944 – 595 mm
    1945 – 802 mm
    1966 – 645 mm
    1969 – 592 mm
    1977 – 751 mm
    1978 – 612 mm
    1979 – 629 mm
    1993 – 744 mm
    1996 – 592 mm
    1997 – 810 mm
    1998 – 619 mm
    2005 – 773 mm
    2008 – 692 mm
    2010 – 642 mm

  14. As per forecast, QBO will be in very strong westerly phase during NEM, this may result in systems developing in central BOB and travelling in NE direction. JAMTEC expects this scenario to happen during NEM.

  15. Current IOD and QBO values exactly matching 1918 iod and qbo values. Even current el nino showing similar trend to 1918 event.

    Chennai got excess rainfall during NEM in 1918. It got 1275mm during NEM.

    TN got normal NEM. It was around 486mm.

  16. 1918 8 0.270121
    1918 9 0.434861
    1918 10 0.581363
    1918 11 0.497757
    1918 12 0.31195

    QBO values 1918
    showed stable values around +10 during NEM.

    As per forecast, IOD will be similar to 1918 values during coming NEM.
    QBO will show stable trend around +10 during coming NEM.

  17. Carl Schreck’s new CFS driven MJO and equatorial wave Hovmoller. It shows a 120 day history and 30 day forecast of 850 hPa zonal wind, the MJO, Equatorial Rossby waves, Kelvin waves, and the low-frequency background/ENSO signal. It also identifies TC genesis during the last 120 days, which is an especially neat feature as it allows one to really visualize the role that the MJO and other modes of tropical variability play in TC activity.

    Now we can observe mjo, KW, ER wave within single frame.

  18. 1884 is one of the analog for this year.

    1884,4 system in total ..a depression(30knts) had made lf over tn in mid oct ,followed by 2 system recurving northeast as D/TS.. atlast season ended with a 70knot system crossing nagai

  19. North East Monsoon 2015 Forecast

    Tamil Nadu likely to get more than 20% of Normal Rainfall this season. The state average might cross 50 CM. North Coastal TN the most beneficiary, and especially Chennai to get excess rainfall this NEM.

    Files Attached…

Please restrict Comments to Weather only

Please log in using one of these methods to post your comment: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s