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Sunday, June 19, 2011
UK Long Range Winter Weather Forecast 2011-2012
UK Long Range Winter Weather Forecast 2011-2012
My UK long range winter weather forecast in Layman's terms and the reasoning behind my basis of a severe winter weather warning for 2011-2012.
Low Solar Activity
Periods of low solar activity at present and what we have seen in recent years influence the Earth's atmosphere by allowing the stratosphere to cool. This has a somewhat more profound effect over Northern Europe and the UK in terms of colder and snowier winters, due to jet stream patterns that block warm air from reaching us and create more moisture. Although sunspot activity has increased somewhat this year and there has been an increase in solar flare activity, the activity is minuscule in comparison to what it should be like during a solar maximum and in terms of frequency. Periods of low solar activity such as this have future repercussions of low solar activity in future cycles and produce extra cloud cover that reflects sunlight with a cooling influence on Earth. The lack of major sunspots and solar flares clearly indicate a slower conveyor belt within the sun. We are now in a very weak solar maximum and my observations indicate that the next solar cycle will also be weak.
La Niña
La Niña is the cooling of the Pacific Ocean near the equator and influences changes to atmospheric pressure and wind changes. In terms of the UK this makes the jet streams in the North Atlantic stronger and therefore offers more precipitation in the form of widespread heavy snowfall during below average temperatures as cold easterlies dominate. Recent indicators from the NOAA suggest neutral conditions for the season ahead, but it is also important to consider the current Pacific Decadal Oscillation (PDO) which switched to a cold phase during 2008. The PDO is a pattern of Pacific climate variability that switches phases and lasts for 20-30 years, resulting in stronger La Niña and weaker El Niño conditions that make the likelihood of La Niña conditions returning very high. However, any return to La Niña conditions this year will not be as strong or have the same influence on the much needed respite that we received in the latter part of last winter, in terms of the milder weather conditions from the high pressure systems it produced in the North Atlantic.
Gulf Stream/North Atlantic Drift
It is visible to see from recent NOAA satellite images that the Gulf Stream/North Atlantic Drift has drastically altered within the last few years. The Gulf Stream is basically a huge volume of heated water that brings warmth to the UK in terms of a mild atmosphere. This softens the climate we experience for the latitude we lie on. For example let's take Newfoundland who lie on a similar latitude to the UK, yet they experience much harsher winters as they do not benefit from this valuable heat source.
Here is a quotation from Matthew Fontaine Maury who was nicknamed ”Father of Modern Oceanography” and "Scientist of the Seas".
"A SIMPLE calculation will show that the quantity of heat discharged over the Atlantic from the waters of the Gulf Stream in a winter's day would be sufficient to raise the whole column of atmosphere that rests upon France and the British Islands from the freezing point to summer heat" (Physical Geography of the Sea, 1855).
Volcanoes
The Icelandic volcanic eruptions Eyjaffjallajokull 2010 and Grimsvotn 2011 are important in terms of sunlight reflection over the Northern Hemisphere. The dust and ash particles can remain within the atmosphere for one to two years and reflect heat away from an already quiet sun. Converted sulfur dioxide emissions from volcanic eruptions can also cause sunlight reflection in the atmosphere. It is also important to consider the currently erupting Chaiten volcano in Chile as this may have the potential to cause long-term climatic effects globally.
Conclusion
I therefore expect the 2011-2012 winter to follow a similar pattern in terms of how November and December was in 2010 for the vast majority of this winter. It will be exceptionally cold and snowy with well below average temperatures. I fully expect to see records broken with the highlands of Scotland being once again particularly hard hit. It is therefore vital to start preparing now in terms of high energy bills and raising awareness amongst the most vulnerable and elderly people of society.
James Madden (UK Long Range Forecaster)
http://www.exactaweather.com/
Published: 18th June 2011 (21:29) BST
Content copyright © 2010-2011. Exacta Weather. All rights reserved.
Saturday, June 11, 2011
Joint Typhoon Warning Centre upgrades the system to a Tropical Cyclone.
METD WEATHER
Wednesday, June 8, 2011
Tropical Storm Keila forms in the Arabian Sea
METD WEATHER
Saturday, June 4, 2011
HAS INDIAN METEOROLOGICAL DEPARTMENT FORGOTTEN SCIENCE OF METEOROLOGY?
AIR ENTERS THE SYSTEM IN A LOW LEVEL CYCLONIC CIRCULATION ( LLC) WHICH IS ANTICLOCKWISE OR THE CYCLONIC SPIN IN LOWER LEVELS AND EXITS THE SYSTEM IN A CLOCKWISE REGION OR ANTI-CYCLONIC REGION IN UPPER AIRFOR MORE UNDERSTANDING CLICK HERETHUS IF THE GENERAL DEFINITION AND NATURAL SCIENCE SAY THAT FOR A CYCLONE, ITS LOWER PORTIONS HAVE ANTICLOCKWISE SPIN AND THE UPPER LEVELS HAVE CLOCK WISE SPIN WHERE THE HEAT OF SYSTEM IS RELEASED!IF SO, HOW CAN IMD SAY THERE IS A CYCLONIC ( CLOCKWISE) SPIN AT UPPER LEVELS. IF SUCH THING HAPPENS, WE GET A HIGH PRESSURE REGION AT THE BASE??????????????????
Update on the Arabian Sea Low!
AKSHAY DEORAS
SEVERE WEATHER FORECASTER
in an unexpected turn in the Tropical Weather system, the previous forecasted low pressure has vanished and the tropical wave has produced another band of thunderstorms in a region of SST over 28C which lacks presence of a lower convergence. This system has strong vortex system at the base,mid level.
Various models confirm that the the forecasted low shall be a Warm Core Low as the warm moist air influxes in the system at lower levels due to torrential heating during spring season.
Low-Mid level vorticity ( Vertical Vorticity) is favorable for upward lifting of parcel of air carrying moisture which is lifted adiabatically and the energy of the parcel is released at the upper level favoring where the system is having a weak upper air divergence ( Outflow of air aloft releasing heat of parcel)
CIMSS models indicate a bare 5-10kt upper air divergence around the system located 730km SW of Mumbai. The area has a wind shear of around 20kt+ and the tendency of wind shear in 24hrs IS INCREASING.
Convection is weakly organized around the geometric center as depicted by higher cloud top temperature of -30C. Typically strong lows ( Depressions) have Cloud Top Temp over -50C.
The 850mb plots are showing developing LLC ( Low level cyclonic circulation) in the region which is a primary step for development of surface lows. The precipitation & surface pressure map shows a formation of 1000mb region by 5th June which shall intensify then. Precipitation map shows formation of weak rain bands in the region after 48hrs. Overall as per the 00z,4th June GFS shows unorganized shape of system.
The GFS Cyclone Prediction maps show the system travelling WNW and expected to make a landfall in coastal Oman on by or on 11th June 2011. The system shall get chance of intensifying in Northern Arabian Sea as the Mid level wind shears have relaxed nature and the upper level winds are forecasted to be weak. The TPW-Precipitable Water shows 60mm+ precipitable water ( Good Moisture content) in the region!
Thursday, June 2, 2011
NORMS USED BY METD WEATHER TO DECLARE SOUTH WEST MONSOON
METD WEATHER
AKSHAY DEORAS
SEVERE WEATHER FORECASTER
NORMS FOR THE ONSET OF MONSOON-
EVERY YEAR,METD WEATHER FORECASTS THE SOUTH-WEST MONSOON FOR INDIA AND THE ONSET DATES AND THE CONSIDERED DATES ARE POSTED OR MARKED ON THE BASIS OF FOLLOWING CONDITIONS-
MONSOON ONSET CONDITIONS AS CONSIDERED BY METD WEATHER
1] PRE-MONSOON SHOWER-
THE RAIN SHOWER/SHOWERS ARRIVING FROM 15 DAYS PRIOR TO MONSOON RAINFALL ARE CONSIDERED AS PRE- MONSOON SHOWER.
ANNUALLY FOR NAGPUR,METD WEATHER ESTIMATES 3-4 SUCH PHASES
2] MONSOON
A) - HEAVY RAINS
THE MONSOON RAINFALL OR THE ONSET OF MONSOON IS CONSIDERED ON THAT DAY WHEN THERE ARE HEAVY RAINS ( *** NOT APPLICABLE FOR RAINFALL DUE TO ANY CYCLONE LANDFALL***).
RAINFALL ACCUMULATION MUST BE MORE THAN 5mm
*** CONVECTIVE RAIN AFTER SUNNY MORNING SHALL NOT BE CONSIDERED AS MONSOON RAINS***
B)- WINDS
THE WINDS ( SURFACE-500MB) MUST BE FROM SOUTH-WEST ATLEAST FOR 48HRS AND HAVING INTENSITY OF MORE THAN 10KT IN ALL LEVEL.
( WINDS FROM SOUTHWEST FOR A DAY ARE NOT TO BE CONSIDERED AS MONSOON WINDS)
C) MOISTURE
***SURFACE RELATIVE HUMIDITY MUST BE GREATER THAN 60% ATLEAST FOR 48HRS
*** THERE MUST BE A DEEP LAYER MOISTURE IN ATMOSPHERE IN LAYERS 500MB-900MB ATLEAST FOR 48HRS WITH SATURATION ***
D) AIR PRESSURE
*** SURFACE AIR PRESSURE IN A REGION ( NOT APPLICABLE FOR HILLY REGION) SHALL BE BELOW 1006 MB CONSECUTIVELY FOR 2-3 DAYS. SINCE LESS PRESSURE REGION INDICATES LOCALITY OF THE MONSOON TROUGH.
*** ANY PERIOD WHEN SURFACE AIR PRESSURE GOES ABOVE THE LIMIT SHALL NOT BE CONSIDERED FOR MONSOON ONSET***
E) TEMPERATURE
*** SURFACE AIR TEMPERATURE MUST DROP TO 35C OR BELOW AFTER PRECIPITATION
*** TEMPERATURE SHALL BE MAINTAINED IN THE MAXIMUM LIMIT AS 35C ( MAX TEMP) ATLEAST FOR 48-72HRS.
*** TEMPERATURE ABOVE THE LIMIT SHALL NOT BE CONSIDERED FOR MONSOON ONSET***
F) CLOUDING
*** DUE TO DEEP LAYER MOISTURE,CLOUDING SHALL BE PRESENT IN THE REGION
*** OVERCAST CONDITION ATLEAST FOR 24HRS CONTINUOUSLY
ANY CLEAR WEATHER DAY WITH ALL THE ABOVE CONDITION POSITIVE ( EXCLUDING RAINFALL) SHALL NOT BE CONSIDERED FOR MONSOON ONSET
G) 850MB MOISTURE TRACK FOR NORTHERN LIMITS OF MONSOON
THE NORTHERN LIMITS OF MONSOON SHALL BE ADVANCED ONLY WHEN 850MB MAP SHOWS MOISTURE OF RELATIVE HUMIDITY GREATER THAN 60% AND BEING MAINTAINED FOR 2-3 DAYS
THE ABOVE ARE THE CONDITIONS WHICH METD WEATHER HAS BEEN CONSIDERING SINCE LAST 2 YEARS AND REGARD AS THE CORRECT MEASURES TO DETERMINE MONSOON ONSET.
THE INDIAN METEOROLOGICAL DEPT NORMS ARE DIFFERENT AND HAVE NO CONNECTION TO THE DATES FORECASTED BY METD WEATHER
ALL THE ABOVE PARAMETERS MUST BE THERE FOR THE PERIOD CONSIDERED
ABSENCE OF EVEN ONE PARAMETER SHALL BE A BARRIER FOR DECLARATION ON THE MONSOON
- AKSHAY DEORAS