Details about the Western Storm invasion

METD Weather

USA,

AKSHAY DEORAS

REGARDING SEVERE WEATHER.

The present RUN of the GFS Long Range models are showing situations clearly than what I had seen day before Yesterday. WEDNESDAY will be a weather day for areas such as LOUISIANA,MISSISSIPPI SOUTH,ALBAMA SOUTH,PENSACOLA,FL. 

These areas will witness some big thunderstorms especially parts of Louisiana. 

I was earlier thinking for supercells in this area but the present run of GFS T+90hrs is impressive. 

The situation is that The instability,Moisture and HIGH surface dewpoints are limited in these states. 

Most of USA is gripped by winter and cool air but some pumping from the GUlf will add to warm air and convective moisture in the southern tips of these areas.

If we see the CAPE forecast,A large 2000J/Kg-1 will be present over parts such as Oklahoma East to South and Texas East to North also at the southern sides of states of LO,MISSISSIPPI.

At that time the Jets at the 850mb will be settling over Northeast Texas and Louisiana.

This will be the 40kt jets. This has to be the start of thunderstorm. As the system progresses,A new 50kt jet appears over MISSISSIPPI. This has the instability as well present in the surrounding. 

This is also favourable. But the best 50kt jets are located little in the interior and as you move inside towards the land from the coast,The energy components decreases. So the activity remains confined to the coast. 

SO there will be thunderstorms in the areas mentioned above and probably  capable to produce supercells. Tornado chance however is low but still I can tell with surely when RUC models come into view.

coastal flood warnings will be issued 

The 5 to 7 inches of rain that parts of western Washington received Friday will pale in comparison to the rainfall that much of California and parts of Arizona will see in the upcoming week.

The south-facing slopes of the hills and mountains of Southern California may locally be doused with as much as 8 to 20 inches of rain. Dangerous, perhaps deadly, flash flooding and mudslides are possible, especially in the burn areas.

Snow will be measured by the several yards in the Sierra and by the yard across the mountains of Arizona.

Strong and potentially damaging winds will accompany the storms as they rake the Southwest.

Between storms there will be a large area of dangerous dense fog and even freezing fog in the Midwest. Use extreme caution driving overnight into early Sunday due to the low visibilities and icy glazed roads and highways from eastern Kansas to Missouri to central Illinois.

Also due to some significant surface jets,waves near california will be 30ft.

Stay tuned for updates

INTERESTING WEATHER TO HAPPEN IN USA BY THURSDAY. POSSIBLE SUPERCELLS IN LOUSIANA

METD INT

USA

AKSHAY DEORAS

It feels great to be back seeing USA models after seeing Argentinan pattern.

At present the weather in USA seems to good and enjoyable except for few states.

yesterday a small low pressure system was hovering over California coastal regions. Also Amazing low level jets of 40 knots resulted in Surfs near California coast and people like John Hallen of SevereWarningSystems.com enjoyed surfs which were more than 23m.

In a few days,90 hrs from now,A large system of low pressure will hit the USA West coast. The 300mb GFS shows intense jets of 160kt. This trough will be digging in and mainly aimed towards the south. As it progresses probably after 138hrs from now,we will be having low level jets at the 850mb near california where the winds are expected to be of 30kt. This will create HUGE surfs and people like JH will get a good chance to surf.At the same time, There will be another low level jet of 40kt over Lousiana coast. I know it is not enough to talk for supercells.

At the same time a high pressure located near usa atlantic gulf will pump instability towards USA southern region especially to lousiana. This will make high dewpoints and CAPE of 2000J/Kg. This value is Large on the scale but you require more cape upto 3000J/Kg for Hails. But I have seen tornado touchdown at the cape of 2000J/Kg also. 

Favoured by Relative Humidity of 90%.

I can say that there will be thunderstorms capable of producing supercells.

The air temperature stands to 70F and I can say Winter is not a barrier. 

Similarly, Rains will come and there might be a coastal flood warning. At present I am looking GFS FORECAST and when it comes to NAM I will get the favoured EHI index which will tell a lot.

It seems there will be supercells as everything is favourable. 

Strong supercell signatures near La Paz,Argentina

Supercells had already exploded in Argentina's Pampas area. As had been forecasted,Santa Rosa had severe hail beat because a supercell of more than 57.9 dBz was parked sometime ago. At present there are no activities going around Santa Rosa but there has been wide activity going around La Paz. A giant squall is approaching La paz. But The dewpoint is about 23 Degree celcius that is more than 75F. This is favourable for development of supercell to Tornado. But the intensity of the squall approaching towards La Paz might decrease and it will become moderate. La paz must be receiving rains at present. 

Reports received from Argentina-

on 11th some circulations were reported to the north of city Santa rosa but weren't tornado.Mendoza also had some amazing supercells. but no tornado 

this might be because of a weak low level shear to the west.

The attachments are

  09:00 GMT,12 th jan <radar one>

08:45 GMT GOES satellite imagery

showing intense,cold cloud tops

Akshay

Argentina tornado outbreak possible at afternoon on 11th Jan

METD,Int

Akshay Deoras

This is the third time, that I am forecasting for Argentina. 

The first forecasting was before 2009 ended. That forecasting had tornadoes. Then I forecasted on 5th Jan but there were supercells as actual trough was not present over the land. It was more pumping action. But the time has come to forecast something HUGE.

the 11jan GFS is showing that a powerful trough is setting over areas of santa rosa. This trough is favoured by CAPE which is also present. CAPE values are 2500J/Kg which indicate another chance of Supercells. The sea level pressure maps are indicating that it will be intense low pressure. This outbreak is possible from Afternoon as local Weather stations are indicating 50% chances of T.storm after 12pm. 

This has to be the best setup till now into this chase season which might show us tornadoes....

also there is  strong divergence at upper levels which is  usually associated with strong vertical velocities in the middle troposphere, and severe weather/heavy rainfall.

We will track the weather and let you know

ALERT FOR RAINFALL ON TUESDAY 12TH JAN 10

METD Int,

Nagpur

 

Alert for ROUGH WEATHER

As is being seen in the satellite imagery,There is a rainfall chance of about 40% on tuesday. This will be a moerate rainfall lasting till tuesday night.

on that day maximum of 21DEG Celcius and min.. of 15DEG C will be there

 

The coldest night was day before yest.. when the temperature dropped 7.5DEG Celcius...

 

Use umbrella on tuesday

 

 

Akshay

 

Argentina to witness many tornadoes or supercells on 5th Jan

METD Int,
AKshay Deoras

The 500mb forecast for 00z 5th jan is impressive. This shows a massive
intensified trough setting over CHILE. In my previous forecasting I
had made it clear that the outbreak would be by 4th jan but now it
seems that 5th Jan would be better.
On 4th jan,The trough will start amplification at CHILE coast which
will start the activity.
But the real show comes on 5th when the upper system and lower system
interacts in the presence of instability and Humidity resulting in the
SURE formation of supercells and further to Tornadoes.
Mendoza would be a better place to begin with. The supercells will
form towards the South East of mendoza and might be traced by the
Radars at Santa Rosa.

when we track severe weather up in Usa, we see the troughs over the
land because USA has a vast area. Unlikely In Argentina the main
principle has to be applied
Generally the greatest lift from the trough is before it comes over
the Severe weather area.
This setup is seen in Argentina on 5th where the trough will pump
moisture and the 850mb jets there will interact and due to winds at
850mb the jets will move south

CAPE values are impressive and high humidity is also available
-------------------------------------------------
Last day, there were supercells in San Rafael and also to the south of
Santa Rosa.
The supercells were strong and produced hails likely but no tornadoes.
This was due to unseasonable 35-40knot jets at 850mb

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Another Active tornado Probabilities in Argentina by Jan 4

METD Int,

Akshay Deoras- Lead Weather Investigator

Argentina Chase season from December 24 has been good with some tornado reported By Reed Timmer on 28th December 09

After that Argentina weather was general with some thunderstorms reported by INTA near south Of Santa Rosa

All the basic GFS models are indicating that there will be another severe weather outbreak soon by 4th jan in argentina mainly at the favored place between Mendoza and Santa Rosa.The 

500mb Geopotential Height, 12hr Height Change, & Vorticity models are indicating that an Upper Level Trough which is arriving from South Pacific Ocean will set over CHILE coast. This will pump Moisture towards southern side. The maps of 200mb which are close to the core of the Jet streams show that low 35-45 knot low level jets will be present there at the affected area. 

If we see the maps for humidity and CAPE they are also suggestive for severe weather.

The outbreak of severe weather will start probably on 3rd Jan as the Trough sets over CHILE and amplifies. 

Then When it is amplified further, IT will start moving in by 5th jan

So tornadic chance is STORNG till 6th Jan. 

 

THIS ABOVE IMAGE IS OF THE 500MB WIND HEIGHT FOR 12Z ON 3RD JAN. HERE YOU CAN SEE THE LIGHT RED THING WHICH IS THE POSITIVE VORTICITY LOCATED NEAR CHILE. POSITIVE VORTICITY IS ASSOCIATED WITH SEVERE WEATHER.

THIS ABOVE IMAGE IS OF THE STREAMLINES AT 200MB FOR 12Z ON 3RD JAN 2010. 

HERE YOU CAN SEE THE LIGHT RED STREAMLINES NEAR CENTER OF LOW PRESSURE.

• Purple shading indicates the speed of the winds at the 200 millibar level, in meters per second. This altitude is near the level of the core of the jet stream. So the tracks of the jet streams can be seen very clearly.
• The streamlines indicate the direction of flow of the wind, which is generally from west to east throughout most of the subtropics, mid- and high-latitudes.
• The color of the streamlines indicates a relative measure of divergence of the flow in the upper troposphere. Orange and red indicates strong divergence at upper levels, usually associated with strong vertical velocities in the middle troposphere, and severe weather/heavy rainfall.

If I had been a chaser, I would have targeted the area between Mendoza and Santa Rosa

This will be HUGE and YOu will get many tornadoes. 

We will track them through RADAR