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
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NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT FRI AUG 20 2010
FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...
DISORGANIZED SHOWERS AND THUNDERSTORMS ARE ASSOCIATED WITH A
WESTWARD-MOVING TROPICAL WAVE OVER THE THE YUCATAN PENINSULA.
THERE IS A LOW CHANCE...10 PERCENT...OF TROPICAL CYCLONE FORMATION
DURING THE NEXT 48 HOURS WHILE THE SYSTEM IS OVER THE BAY OF
CAMPECHE.
A BROAD AREA OF LOW PRESSURE HAS FORMED ABOUT 275 MILES SOUTH-
SOUTHWEST OF THE CAPE VERDE ISLANDS. SHOWER AND THUNDERSTORM
ACTIVITY IS GRADUALLY BECOMING BETTER ORGANIZED...AND A TROPICAL
DEPRESSION COULD FORM DURING THE NEXT COUPLE OF DAYS. THERE IS A
MEDIUM CHANCE...40 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES SLOWLY WESTWARD.
ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
$$
FORECASTER BLAKE
WHXX01 KWBC 201125
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1125 UTC FRI AUG 20 2010
DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.
ATLANTIC OBJECTIVE AIDS FOR
DISTURBANCE INVEST (AL952010) 20100820 0600 UTC
...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
100820 0600 100820 1800 100821 0600 100821 1800
LAT LON LAT LON LAT LON LAT LON
BAMS 11.0N 25.3W 11.5N 26.5W 11.8N 28.2W 12.1N 30.2W
BAMD 11.0N 25.3W 11.4N 26.5W 12.0N 28.1W 12.6N 30.2W
BAMM 11.0N 25.3W 11.5N 26.4W 11.9N 28.1W 12.4N 30.2W
LBAR 11.0N 25.3W 11.4N 26.9W 12.3N 29.1W 13.2N 31.9W
SHIP 25KTS 29KTS 35KTS 45KTS
DSHP 25KTS 29KTS 35KTS 45KTS
...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
100822 0600 100823 0600 100824 0600 100825 0600
LAT LON LAT LON LAT LON LAT LON
BAMS 12.5N 32.3W 13.9N 37.2W 16.8N 44.3W 19.1N 50.9W
BAMD 13.1N 32.8W 14.0N 38.8W 15.8N 44.5W 19.7N 49.0W
BAMM 12.8N 32.5W 14.0N 37.9W 16.4N 44.5W 19.3N 50.1W
LBAR 14.1N 35.1W 15.2N 42.3W 14.7N 48.7W 19.2N 49.5W
SHIP 56KTS 81KTS 91KTS 92KTS
DSHP 56KTS 81KTS 91KTS 92KTS
...INITIAL CONDITIONS...
LATCUR = 11.0N LONCUR = 25.3W DIRCUR = 270DEG SPDCUR = 6KT
LATM12 = 11.0N LONM12 = 24.1W DIRM12 = 270DEG SPDM12 = 5KT
LATM24 = 11.0N LONM24 = 22.4W
WNDCUR = 25KT RMAXWD = 60NM WNDM12 = 25KT
CENPRS = 1008MB OUTPRS = 1010MB OUTRAD = 150NM SDEPTH = S
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM
$$
NNNN
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT FRI AUG 20 2010
FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...
DISORGANIZED SHOWERS AND THUNDERSTORMS ARE ASSOCIATED WITH A
WESTWARD-MOVING TROPICAL WAVE OVER THE THE YUCATAN PENINSULA.
THERE IS A LOW CHANCE...10 PERCENT...OF TROPICAL CYCLONE FORMATION
DURING THE NEXT 48 HOURS WHILE THE SYSTEM IS OVER THE BAY OF
CAMPECHE.
A BROAD AREA OF LOW PRESSURE HAS FORMED ABOUT 275 MILES SOUTH-
SOUTHWEST OF THE CAPE VERDE ISLANDS. SHOWER AND THUNDERSTORM
ACTIVITY IS GRADUALLY BECOMING BETTER ORGANIZED...AND A TROPICAL
DEPRESSION COULD FORM DURING THE NEXT COUPLE OF DAYS. THERE IS A
MEDIUM CHANCE...40 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES SLOWLY WESTWARD.
ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
$$
FORECASTER BLAKE
ABNT20 KNHC 201148
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT FRI AUG 20 2010
FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...
DISORGANIZED SHOWERS AND THUNDERSTORMS ARE ASSOCIATED WITH A
WESTWARD-MOVING TROPICAL WAVE OVER THE THE YUCATAN PENINSULA.
THERE IS A LOW CHANCE...10 PERCENT...OF TROPICAL CYCLONE FORMATION
DURING THE NEXT 48 HOURS WHILE THE SYSTEM IS OVER THE BAY OF
CAMPECHE.
A BROAD AREA OF LOW PRESSURE HAS FORMED ABOUT 275 MILES SOUTH-
SOUTHWEST OF THE CAPE VERDE ISLANDS. SHOWER AND THUNDERSTORM
ACTIVITY IS GRADUALLY BECOMING BETTER ORGANIZED...AND A TROPICAL
DEPRESSION COULD FORM DURING THE NEXT COUPLE OF DAYS. THERE IS A
MEDIUM CHANCE...40 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES SLOWLY WESTWARD.
ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
$$
FORECASTER BLAKE
Steak fries and pork and beans.
on the other hand, they may not have classified it a TD or TS yet and no recon cause jason has declared the season a fish. I believe I just saw on the local news the NHC workers are packing their bags for the season and going home and all of the computers were being put away til next season.
Hi Storm. Can you post one of those charts that shows the highs over the
Atlantic right now?
Hi Storm
Likewise. This one has the look of being one of those large CV systems. The aerial coverage is very extensive. Slow movers have a tendency of becoming very strong but that also increases the odds of an early recurve.
All we can do is watch and wait until it settles down into some discernible pattern going forward.
BAMS 12.5N 32.3W 13.9N 37.2W 16.8N 44.3W 19.1N 50.9W
BAMD 13.1N 32.8W 14.0N 38.8W 15.8N 44.5W 19.7N 49.0W
BAMM 12.8N 32.5W 14.0N 37.9W 16.4N 44.5W 19.3N 50.1W
LBAR 14.1N 35.1W 15.2N 42.3W 14.7N 48.7W 19.2N 49.5..........................
Near 20N and 50W on all of them too and moving WNW to NW.....better be a strong high to turn her back west.....
lol.
BFN
:)
invest_RENUMBER_ep922010_ep082010.ren 20-Aug-2010 11:46 931
Link
Sips black coffee with one eye open....
As of Fri 20 Aug 2010 12:04:01Z
No Active Tropical Warnings in the Atlantic, Caribbean, or Gulf of Mexico
Active Tropical Warnings in the Northwest Pacific, North Indian Ocean, Central Pacific, Eastern Pacific, or Southern Hemisphere
Current Northwest Pacific* Tropical Systems
Tropical Cyclone Formation Alert WTPN21
Issued at 20/0430Z
Current Central/Eastern Pacific Tropical Systems
Tropical Cyclone Formation Alert WTPN21
Issued at 20/0900Z
As of Tue 17 Aug 2010 10:30:02Z
2010 Storms
All Active Year
Atlantic
95L.INVEST
East Pacific
08E.EIGHT(T.C.F.W.)
Central Pacific
West Pacific
94W.INVEST
93W.INVEST(T.C.F.A.)
Indian Ocean
Southern Hemisphere
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