Sunday, May 20, 2018

Monsoon Watch --4 ...Quantum Analysis...20th May 2018

Quantum Analysis is evaluated for the amount of summer monsoon rainfall over Indian monsoon region during June- July....

Forecasting Methods adopted for the Indian Monsoons:

Gowarikar(1989) developed parametric and multiple power regression (MPR) models with 15 predictors for LRF of AISMR, which were later modified in 1991 to include 16 predictor parameters. The parametric model is qualitative and indicates the likelihood of the monsoon rainfall to be excess or deficient.
Thapliyal (1990) evaluated the relative performance of multiple regression, and Navone and Ceccatto (1994) have used 'feed-forward' neural network technique for the prediction of Indian monsoon rainfall with two predictors (500 hPa ridge location and Darwin SLP tendency from January to April).
The results of a recent work by Krishna Kumar (1997) indicate that a single component accounts for about half of the total variance in the predictors

Most of the studies on LRF of Indian monsoon rainfall were based on empirical or statistical techniques till 2010. IITM, Pune has recently implemented the state-of-the-art coupled climate model, the Coupled Forecasting System (CFS) developed by the National Centers for Environmental Prediction (NCEP), USA. These statistical techniques range from simple correlation analysis to advanced procedures.

Vagaries' View Point:

Vagaries leans on, and believes in the "Gowarikar Method" with 16 parameters. The results of this old but proven method has been successful. For Vagaries' forecast and analysis made in the "Arrival and quantum Monsoon Watch" series, I combine a few of them along with Dynamical models for a personal analysis and estimate.
15 initial parameters from the months March, April and May are used to analysis and forecast the simulation of Indian monsoon rainfall during June to October. These initial conditions were carefully selected  to span the evolution of both the atmosphere and ocean.

We have to take into consideration most of the 15 parameters (Gowarikar Method) before making an assessment, and these have to be analysed one by one. The prominent among the 15 are , ENSO, March temperatures of North India and East Coast, Himalayan Snow cover till March and SOI to name a few.
Of-course, I am not going to take each and every one of the 15 here, but, derive at an estimate on these basis and on the new model developed. I hope readers of vagaries trust that I have tried my best to estimate as accurately as possible.

Calculating the amount of rainfall, region wise, is of utmost importance, as SWM contributes to almost 80% of the annual total rainfall over India.
In this article, Quantum Analysis is evaluated for the amount of summer monsoon rainfall over Indian monsoon region during June and July.

The 500 hpa parameter is of importance in April. The mean latitudinal location of the 500 hPa ridge along 75°E in April over India, first identified by Banerjee (1978), is considered to be one of the most important predictors. The mid-tropospheric anticyclone over southern India migrates from 11.5°N in January to its northern most position of 28.5°N during July.
From October, the ridge starts shifting back southward. A more Northward location indicates better performance of the monsoon and vice versa. It also showed that the negative correlation of the March ridge was more dominant with the monsoon rainfall of the peninsular India, while the positive correlation of the April ridge was more dominant with the monsoon rainfall of Northern India.

ENSO factor in arriving at the rainfall amount is also of importance. The interface is the sea surface: that is where the transfers of water (evaporation/precipitation)
and momentum occur. An accurate coupling of the fast atmosphere to the slow ocean is essential to simulate the ENSO, which in turn can simulate the interannual
variability of Indian monsoon. Unfortunately, getting an accurate, or near to accurate forecast of the ENSO for the next 2 months is difficult, with no guarantee of accuracy or performance surety.

Currently we see neutral ENSO conditions persisting. But, there is a possibility of  Neutral event persisting till October. Now, this would result in normal Monsoon condition from June thru  October.( "Break Monsoon" conditions apart). 
After August, a 50-50 chance of neutral conditions continuing.

We depend also on other parameters.
Normally, Pulses from the Eastern Pacific area, that is S.China sea, would mean depressions and systems originating from the Bay. 'In Situ" systems and systems from the Far east would contribute to the rainfall to the east Coast thru Central India and into Gujarat and even into Sindh (Pakistan). No El-Nino, would mean no stopping  these pulses, and in fact not encourage WDs into coming down south, (more South than normal).
This may persist till  June, and then rapidly the flow of systems should increase from Bay in July.

The performance of Vagaries' Monsoon Watch Quantum Analysis is evaluated for the amount of summer monsoon rainfall over Indian monsoon region during June to SWM withdrawal in 2 phases. (June/July and August/September).

Why in 2 phases ? Because, I believe it is impossible to give actual Quantum forecast now (In May) for sometime in September...that is 120 days ahead !). I am not competent to give a forecast 90 - 120 days in advance, 
so Monsoon forecast will be 
1)...For June and July and
2)... August and September ..this is tentative and will be published in 2nd week July.

A) First 15 days of June 2018 sees 
i) Monsoon advancing from Kerala thru upto Central India, and into NE States and West Bengal.
ii) Heat ( Normal to above Normal) in Northern India, and Pakistan.
Monsoon advances into Central India and North India between 20th - 30th June.
iii) Monsoon moves into Pakistan around 1st - 10th of July in phases.

B) Mid June to July end, we can see normal rainfall and progress of the SWM in all of  Sub-Continent regions. Neutral conditions in the Pacific Oceans will send a few "pulses" to create "in situ" systems in the Bay, and the first 2 months could see around 3/4 noteworthy systems traversing the Sub continent. WDs will be few, hence, we can expect a few systems from Bay to track towards Central and Northern India, resulting in good rains in the plains of N.India and Northern Pakistan regions..and fairly good above normal rains in Nepal.

Slightly above normal rains likely along West Coast of India and A.P. coast and Odisha.
Weaker rains possible in June in Marathwada and parts of Telengana.

Thus, except for the above patch, June and July rains should be normal for the rest of the regions.

This estimate is based absolutely on the situation as it shows and stands today. 
Things, if and when they change (drastically) will be posted and Vagaries readers will be kept well informed, of any variation in the forecast. 
These are my personal views, and should not be depended upon commercially or otherwise.  They may differ from other models.

Saturday, May 19, 2018

Posted 19th May Night:

South West Monsoon is advancing into the Southern Andaman Region. Monsoon will cover the South Andamans by 21st May. 
A weak Low will bring strong South/South Westerly winds in the next 48 hrs in the South Bay region.

Day Temperatures on 19th May: Top 10 on 19th:
1 Chandrapur  47.8 °C
2 Bramhapuri  47.1 °C
3 Nagpur Sonegaon  46.2 °C
4 Wardha  45.6 °C
5 Khajuraho  45.0 °C
6 Khargone  45.0 °C
7 Sheopur 45.0 °C
8 Chittorgarh  44.9 °C
9 Akola  44.7 °C
10 Amraoti  44.6 °C




For Mumbai... Please note that the news circulating about Sagar Cyclone is false and not going to affect us. 

Monday, May 14, 2018

Posted 14th May Night"

Low pressure formed in the Arabian Sea will not have any effect on the Sub Continent Weather,
Somali Currents may strengthen to some extent.

As mentioned in Monsoon Watch -3 Part -2 (Additional), the estimated dates of arrival of Monsoon in India remains unchanged...

SWM should hit South Andaman Sea around 20th.May (12/15th May), and rest Andaman Islands by 23rd May 2018.
Generally moves up (normally) the Bay at a sustained speed, and Kolkata should see Monsoon arrival by the 14th of June.


Vagaries would estimate the Monsoon to reach Maldives around the 24th of May 2018 (20th May), Sri Lanka around 29th/30th of May (25th May).
Kerala by the 2nd/4th June (1st June)...
Hence, maintaining and presuming the normal rate of progress, As the Seasonal Low strengthens, Monsoon could "slide " up the coast to be in Goa should get Monsoon rains by around 8th/10th June (5th June).... NE States can also see Monsoon resume around that date.

Mumbai by 12th/14th June (9th June)..... Pre Monsoon thunder showers in Mumbai could start from around 4th/5th June 2018.

Friday, May 11, 2018

Kauai Experiences the U.S. 24-h Precipitation Record

The north shore of the Hawaiian island Kauai may have set a national record for the most rainfall ever in a 24-hour period, according to preliminary data. Rain gauges in Waipa, about a mile west of Hanalei, recorded 49.69 inches (1262 mms) on April 14 and 15.
Intense rainfall cut a path through Hanalei, which received 28 inches (713 mm) of rainfall. The U.S. Army and National Guard airlifted more than 220 people from the Haena and Wainiha areas after Kuhio Highway, the only road that leads to them, was blocked by landslides. Floodwaters carried off bison, some of which were rescued from the ocean. Ocean water around Kauai was an unusual shade of orange for a week after the storm because red–orange clay from the mountaintops was swept into the water by the rain.
The torrential rain began on April 12, when an elongated area of low pressure disrupted the normal flow of the northeast trade winds above Oahu. This caused heavy rainfall as the system strengthened and moved slowly over Kauai. The rain event lasted through April 19.

Kauai Experiences the U.S. 24-h Precipitation Record: ...Cliff Mass Weather Blog.

Heavy precipitation on Kauai was headline news two weeks ago, with flooding and substantial damage on the north side of that mountainous island.

But additional precipitation records have become available and it now appears that the precipitation in some locations went beyond extraordinary, producing 24-h amounts that have never been documented anywhere in the U.S. at any time:  the all-time 24-h precipitation record of the United States.

That is something amazing.


This week the National Weather Service released a special statement that a rain gauge in Waipa, about a mile west of Hanalei, on the north side of Kauai, received 49.69 inches...1262 mms.... during the 24 hours ending 12:45 PM HST on Saturday April 15th (that is 2145 UTC/GMT).  As an aside, the message was written by Kevin Kodama, the NWS Service Hydrologist in Honolulu, and a graduate of the UW Atmospheric Sciences department).


An official review team will evaluate the quality and consistency of the rain gauge data to determine whether the record was actually broken.   This was not an official NOAA rain gauge but one installed by the Waipa Foundation.   If true, the April 14-15th total would smash the previous U.S. 24-h record of 43 inches observed in Alvin, Texas on July 25-26, 1979.

Just stunning.  A huge collection of lightning strikes over the northern and northeast side of Kauai (over 3000 of them).



Wednesday, May 09, 2018

Monsoon Watch -3... 2018 (Additional)...May 9th 2018.
Monsoon Arrival Dates Estimate.

The arrival date is calculated seeing today's position.Further from today, we presume the normal rate of progress/developments. This initial estimated dates are subject to some changes, and will be finalised later, when the puzzle pieces get better arranged.
(Dates in brackets are the normal dates of arrival).

As of today, there seems to be a slight delay in both, Arabian Sea and Bay Branches of the Monsoon. There continues to be a doubt on the timely arrival of the Monsoon in the Bay branch.

Arabian Sea Branch: The LWD parameter is not strong, and developed. Otherwise, There is not much improvement in some of the parameters, there is still much to be achieved, and most parameters are still lagging behind time, and are -ve.
The Arabian Sea branch, now affected by the "getting organised" Somali current winds and the equatorial winds at the equator. They can recover provided the winds regroup fast.

On these calculations, Vagaries would estimate the Monsoon to reach Maldives around the 24th of May 2018 (20th May), Sri Lanka around 29th/30th of May (25th May).
Kerala by the 2nd/4th June (1st June).
Hence, maintaining and presuming the normal rate of progress, As the Seasonal Low strengthens, Monsoon could "slide " up the coast to be in Goa should get Monsoon rains by around 8th/10th June (5th June). NE States can also see Monsoon resume around that date.

 Mumbai by 12th/14th June (9th June). Pre Monsoon thunder showers could start from around 4th/5th June 2018.

Bay Branch: A weak Western Disturbance  was active the Northern regions of the sub continent.Violent thunder Storms/Dust Storms ravaged through NW and North India due to inter action of WD and Eastern moist winds and of course the land heating.
North Temperatures have dropped in the last few days, considerably.(See Map below)Bay branch needs to wait a few days for the the pulses from the East in the Bay to resume for Low formations. 

SWM should hit South Andaman Sea around 20th.May (12/15th May), and rest Andaman Islands by 23rd May 2018.
Generally moves up (normally) the Bay at a sustained speed, and Kolkata should see Monsoon arrival by the 14th of June.
                                               



We stop at this initial progress, and work out further region wise progress at a later date  (as is the usual practise in Vagaries' MWs).

These Dates are worked out and estimated as per my personal calculations and may not be used for commercial purposes.The dates are not binding on anyone and no responsibility is taken if used for any purposes.

----------------------------------------------------------------------------------------------------End of MW-3 Part 2 (Additional)
--------------------------------------------------------------------------
Back to back Western Disturbances interacting with moist easterly winds and helped by high temperatures caused instability in the atmosphere in NW and North India. Resulting in violent thunderstorms/Dust storms.

Low temperatures recorded in North India (Minimum...as reproduced from Navdeep Dahiya
LOW MINIMUM TEMPERATURE IN PLAINS OF NORTH INDIA.
DATED: 9 MAY 2018
--------------------------------------
PUNJAB-
Balachar: 17.1°c
Hosiyarpur: 17.4°c  Fatehgarhsahib: 18.2°c
Kapurthala: 18.2°c  Tarn taran: 18.6°c
Jalandhar: 19.0°c  Ludhiana: 19.3°c  Amritsar: 19.6°c
Moga: 19.9°c  Patiala: 20.1°c  Bhatinda: 20.5°c
----------------------------------
Chandigarh: 20.0°c
----------------------------------
HARYANA-
Yamunanagar: 15.4°c
Ambala: 16.5°c
Kaithal: 16.6°c  Panchkula: 17.2°c  Karnal: 17.4°c
Kurukshetra: 17.4°c  Narayangarh: 18.0°  Sonipat: 18.2°c
Uchani: 18.5°c Panipat: 18.6°c Israna: 19.0°c
Fatehbad: 19.4°c Hisar: 20.1°c Rohtak: 20.7°c
Jhajjar: 21.0°c  Faridabad: 21.8°c  Gurgaon: 21.8°c
---------------------------------------
DELHI-
Pusa(iari): 19.0°c
Narela: 20.1°c  Mungeshpur: 20.4°c
LodhiRoad: 21.0°c  Jafarpur: 21.6°c  Safdarjung: 22.4°c
---------------------------------------
NW-UTTARPRADESH-
Muzzafarnagar: 17.4°c
Meerut: 18.6°c  Bareilly: 19.3°c
Hindon: 19.5°c  Bahraich: 20.6°c  Aligarh: 21.6°c
---------------------------------
RAJASTHAN-  Siker: 20.0°c..Churu: 21.8°c
----------------------------------
Data: IMD

Monday, May 07, 2018

MW 3 PART 2 DELAYED DUE TO CHANGING SITUATION. WILL BE PUBLISHED ON WEDNESDAY NIGHT. 

Monsoon Watch --4 ...Quantum Analysis...20th May 2018 Quantum Analysis is evaluated for the amount of summer monsoon rainfall over Indian m...