The Atlantic is quiet; Russian heat wave ends; huge 926 mb South Indian Ocean storm
A tropical wave in the western Caribbean approaching Mexico's Yucatan Peninsula is generating disorganized thunderstorms. Wind shear is a moderate 10 - 15 knots over the region, and water vapor satellite images show that there is some dry air to the west that will interfere with any development that might occur. None of the reliable computer models develop this wave, and NHC is giving it a 10% chance of developing into a tropical depression.
Figure 1. Morning satellite image of the disturbed region of weather of the coast of Africa, south of the Cape Verdes Islands.
The GFS, NOGAPS, and ECMWF models continue to predict that a tropical storm will form between Africa and the Lesser Antilles Islands sometime in the period 3 - 6 days from now. There is an area of disturbed weather south of the Cape Verdes Islands, but there is no obvious organization to the cloud pattern. Wind shear is a hefty 20 - 30 knots in the region, and the disturbance is a 1 - 2 day journey away from reaching a lower shear area where development can occur. Preliminary indications are that if a storm did develop in this region, it would track west-northwest and pass well to the northeast of the Lesser Antilles Islands 7 - 8 days from now. However, 7-day forecasts of a storm that hasn't even formed yet are not to be trusted.
Figure 2. The cold front that brought an end to the Great Russian Heat Wave of 2010 lies east of Moscow in the NASA MODIS photo taken at 8:35 UTC August 19, 2010. Smoke from wildfires is visible over a wide swath of Russia east of the front. Image credit: NASA.
The Great Russian Heat Wave of 2010 ends
A powerful cold front swept through Russia yesterday and today, finally bringing an end to the Great Russian Heat Wave of 2010. Temperatures at Moscow's Domodedovo airport hit 25°C (77°F) today, which is still 4°C (7°F) above average, but the high temperature since late June. Moscow has seen 62 consecutive days with a high temperature above average, but the latest forecast for Moscow predicts that remarkable string will come to an end Friday, when the high will reach just 17°C (62°F).
Massive 926 mb extratropical storm generating huge waves off Antarctica
One of the most intense extratropical storms in recent years is churning up the waters near the coast of Antarctica in the South Indian Ocean. The powerful storm peaked in intensity yesterday afternoon with a central pressure of 926 mb--the type of pressure typically found in a Category 4 hurricane. Storms this intense form on average once per year, or perhaps less often, according to an email I received from Jeff Callaghan of the Australia Bureau of Meteorology. Since extratropical storms do not form eyewalls, the winds at the surface from this monster storm probably reached "only" 100 - 120 mph (equivalent to a Category 2 or 3 hurricane.) The storm is forecast to generate huge waves with a significant wave height of 13 meters (44 feet) today, according to the NOAA Wavewatch III model (Figure 3.) I have flown into an extratropical storm this intense--in 1989, I participated in a field project based in Maine that intercepted a remarkable extratropical storm that "bombed" into a 928 mb low south of the Canadian Maritime provinces. You can read my story of that somewhat harrowing flight here.
Figure 3. Satellite image taken at 8:10 UTC August 19, 2010, showing the intense extratropical cyclone that has weakened to 940 mb in the South Indian Ocean near the coast of Antarctica. Image credit: NASA.
Figure 4. Surface pressure analysis from 18 UTC August 18, 2010, showing a 926 mb low in the South Indian Ocean, just north of Antarctica. Image credit: Jeff Callaghan, Australia Bureau of Meteorology.
Figure 5. Predicted wave height from the NOAA Wavewatch III model for 2pm EDT (18 UTC) today, August 19, 2010. Peak wave heights of 13 meters (44 feet) are projected over ocean areas between Antarctica and Australia. Long-period waves (19 seconds between crests) up to 7 meters (22 feet) high are predicted to affect the southwest coast of Australia by Sunday. The waves are predicted to propagate eastwards to New Zealand 8 - 9 days from now, and be a respectable 4 - 5 meters high then.
Jeff Masters
Reader Comments
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 — Blog Index
Raining here now.
18Z NOGAPS...
Thanks in advance for the help.
I dont see any shear in that picture... Cool shot of a Meso though...
ABNT20 KNHC 192336
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT THU AUG 19 2010
FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...
SHOWERS AND THUNDERSTORMS CONTINUE IN ASSOCIATION WITH A
WESTWARD-MOVING TROPICAL WAVE OVER THE NORTHWESTERN CARIBBEAN SEA.
HOWEVER...NO SIGNIFICANT DEVELOPMENT IS EXPECTED BEFORE THIS SYSTEM
MOVES OVER THE YUCATAN PENINSULA AND CENTRAL AMERICA ON FRIDAY.
THERE IS A LOW CHANCE...10 PERCENT...OF TROPICAL CYCLONE FORMATION
DURING THE NEXT 48 HOURS.
A LARGE AREA OF DISTURBED WEATHER EXTENDS FROM THE WEST COAST OF
AFRICA TO THE SOUTH OF THE CAPE VERDE ISLANDS. THE ASSOCIATED
SHOWER AND THUNDERSTORM ACTIVITY HAS BECOME SLIGHTLY BETTER
ORGANIZED THIS EVENING ABOUT 250 MILES SOUTH-SOUTHWEST OF THE
SOUTHERN CAPE VERDE ISLANDS. ENVIRONMENTAL CONDITIONS APPEAR
FAVORABLE FOR ADDITIONAL SLOW DEVELOPMENT OF THIS SYSTEM AS IT
MOVES WESTWARD AT 5 TO 10 MPH. THERE IS A LOW CHANCE...20
PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS.
ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
$$
FORECASTER BEVEN
\
Been raining in Mobile most of the afternoon. Stopped now though. What's up?
Tropical Disturbance Summary
20:30 PM UTC August 19 2010
=================================
An area of convection (94W) located at 18.8N 123.8E or 300 NM north northeast of Manila, Philippines. Animated infrared satellite imagery indicates convection is consolidating over a loosely defined low level circulation center with some indications that upper level outflow is starting to become enhanced into a tropical upper tropospheric trough to the north. A 1725z AMSR-E microwave pass shows banding forming in the mid to upper levels of the system. The lower level, as depicted by the 36ghz image, still shows a relatively weak surface circulation center.
Maximum sustained winds near the center is 15-20 knots with a minimum sea level pressure of 1008 MB. The potential for this disturbance to form into a significant tropical cyclone within the next 24 hours is UPGRADED TO FAIR.
=============
70 percent chance of developing into a tropical cyclone from Typhoon 2000 website
Raining good here now. 79.5 outside.
Okay thank you StormW. I have a fair amount of common sense and can usually sort things out on my own, but weather has SO many terms and variables. For the first two years I suffered quietly. I decided this year to ask for clarification for terms and conditions that I do not understand. Now, back to quietly lurking and learning.
North Atlantic (0)
I would say yes.
Lol. I don't even have to look. I know who you mean. Been arguing with him for six months about that.
Tropical Weather Analysis - August 19 2010 - Tropical Update!
YES - 0-10% Chance - Beware of Orange - Red....big time !
Lucky to have paterson still he's a good coach
Cool, what do you think about the CV presentation?
That would be the one. He may be right about a storm recurving but the not the NAO thing. I'm sure he just loves me. :)
You mean the Cape Verde system?
Tropical Cyclone Outlook
0:00 AM UTC August 20 2010
=======================================
An area of disturbed weather has formed about 175 miles southwest of Manzanillo, Mexico. Some additional development of this system is possible during the next day or two before it moves westward over cooler waters.
Tropical Cyclone Formation Potential
======================================
There is a LOW chance of this disturbance to form into a tropical cyclone within the next 48 hours
I keep looking at the monsoonal activity in the NIndian and wondering what it's going to be like when that monsoon starts treking south again....
Seems things are picking up...
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU AUG 19 2010
BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.
...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 12N33W TO 17N37W TO 24N38W MOVING W
AT 15-20 KT. SATELLITE PRESENTATION INDICATES LOW-LEVEL CYCLONIC
FLOW ALONG THE WAVE AXIS AND THIS WAS ALSO NOTED ON AN EARLIER
MORNING ASCAT PASS AROUND 19/1234 UTC OVER THE NORTHERN PORTION
OF THE WAVE. AN AREA OF MAXIMUM DEEP LAYER MOISTURE IS OBSERVED
ON THE TPW IMAGERY FROM 06N-27N E OF 42W...HOWEVER MUCH OF THIS
MOISTURE IS POSITIONED BENEATH A STABLE SAHARAN AIR LAYER THAT
COVERS MUCH OF THE ATLC E OF 50W. NO SIGNIFICANT DEEP ORGANIZED
CONVECTION ACCOMPANIES THE WAVE THIS EVENING.
TROPICAL WAVE EXTENDS FROM 10N83W TO 17N85W TO 24N85W MOVING W
AT 15-20 KT. LOW-LEVEL CYCLONIC FLOW IS NOTED ON SATELLITE
IMAGERY ACROSS THE WESTERN CARIBBEAN SEA AND CENTRAL AMERICA
THAT ALSO COINCIDES WITH AN AREA OF ENHANCED MOISTURE EVIDENT ON
TPW IMAGERY FROM 09N-22N BETWEEN 78W-90W. SCATTERED MODERATE AND
ISOLATED STRONG CONVECTION IS FROM 11N-24N BETWEEN 78W-91W.
WATER VAPOR IMAGERY ALSO INDICATES AN UPPER LEVEL TROUGH IS
LOCATED ACROSS THE YUCATAN PENINSULA EXTENDING SOUTHWARD TO SW
GUATEMALA THAT IS ENHANCING ONGOING CONVECTION WEST OF THE WAVE.
...ITCZ...
ITCZ AXIS IS CENTERED ALONG 13N38W 11N47W 13N55W. EAST OF THE
TROPICAL WAVE BETWEEN 33W-38W...A MONSOONAL TROUGH IS ANALYZED
AS A SURFACE TROUGH IN PLACE OF THE ITCZ FROM EASTERN MAURITANIA
NEAR 19N06W TO THE W AFRICA COAST NEAR 14N17W AND INTO THE E
ATLC TO 13N27W. THIS MONSOONAL TROUGH HAS PERSISTED OVER THE
PAST FEW DAYS WITH WESTERLY LOW-LEVEL FLOW OBSERVED S OF 13N. AN
EARLIER MORNING ASCAT PASS AROUND 19/1054 UTC INDICATED THE
BEGINNINGS OF A BROAD LOW-LEVEL CIRCULATION SW OF THE CAPE VERDE
ISLANDS NEAR 13N26W. SCATTERED MODERATE AND ISOLATED STRONG
CONVECTION REMAINS UNORGANIZED AND FOCUSED IN THE VICINITY OF
THIS MONSOONAL TROUGH FROM 08N-14N BETWEEN 16W-30W. ELSEWHERE...
SCATTERED MODERATE CONVECTION IS S OF THE ITCZ AXIS FROM 04N-11N
BETWEEN 30W-39W.
...DISCUSSION...
the wind barbs on the map would lead me to disagree with you
also it says new next to it which leads me to believe the next map will show it
Looks like it's on it's way....
ugh! I am the worst weather photographer ever! By time I find my camera everything's over with. We had a line of storms come thru the other day preceded by 60mph winds. Trees bending over branches hitting the house. We didn't know if it was a tornado or what. And of course I was griping about finding my camera and my daughter was griping at me..."Mom! You're always on a weather blog! How could you not know this was coming!??" Lil smart-behind. Lol.
MARK
11.98N/30.00W
(30W max sat reach)
So now where does it go?
Models are hell bent on the cyclone going way out into the Atlantic Ocean graveyard as a potential major hurricane. However I beg to differ on how far east they are showing it recurve. Now we all know this system will recurve, but where and when will this happen is the ultimate question asked. So with no further ado, here is my reasoning: -NAO currently bottoming out, and slowly rebounding towards neutral and then positive levels as it nears the 14 day forecast. So what does this mean? It means that the A/B high has peaked at its most weakest point now, and that it will slowly begin to respond and be quite strong by day 14. Now if this is true then why are the models too far out to sea with the system? Answer is I don't know why.
Why? Well we have a +PNA trending neutral to negative which means the ridge over the western CONUS is quite strong today will continue to deamplify and the trough downstream will do the same. Now the models show a shortwave closing off at 500mb as a cutoff low develops next week as a strong ridge builds over the NE CONUS and Maritimes of Canada do to the building heights on the models. Now this was from a few days ago, today however the models trended towards a strong -NAO pattern with a strong Greenland blocking ridge in place and a 50/50 low over and near Labador, Canada. This 50/50 low or 50n/50w latitude/longitude low pressure center is associated with a modeled highly amplified trough which digs seward towards the hurricane the models develop. This trough forces a weakness within the A/B high and extension of the eastern US high as the PNA ridge deamplifies and allows a western US trough to come through or rather zonal flow at 500mb. Now the difference is that the models amplify the trough because the ridge downstream becomes amplified. Now I think the opposite occurs with a rather strong zonal flow developing allows the trough to shear out and weaken rather then strengthen. So this trough shears out and the A/B high strengthens as the models have the NAO index back to positive by day 14 and our hurricane nears 70w/25n. With that in mind it sounds like I expect perhaps a major hurricane in a threatening position SW of Bermuda. Right now that are my thoughts on the models vs reality debate. I hope you enjoyed them.
What? Why would an anticyclone, an upper level feature, force a system that's being steered by the 850 to 500 mb flow, west?
The upper level steering does not affect a system this weak.
Viewing: 1201 - 1251
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 — Blog Index