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
What are you doing up this late?
Rays was playing on the West Coast....LOL....hey my friend.
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
202 PM EDT THU AUG 19 2010
VALID 12Z SUN AUG 22 2010 - 12Z THU AUG 26 2010
PRELIMINARY UPDATE...
USED A BLEND OF THE 00Z ECMWF AND ITS ACCOMPANYING 50 MEMBER
ENSEMBLE MEAN TO UPDATE THE FRONTS AND PRESSURES FOR DAYS 3
THROUGH 7. ALL IN ALL...THE VARIOUS MODELS AND ENSEMBLE MEANS ARE
IN GOOD AGREEMENT THIS PERIOD...SHOWING A SUBSTANTIAL FULL
LATITUDE COLD FRONT KNIFING ACROSS THE PLAINS...AND A
CLOSED...STACKED...CYCLONIC CIRCULATION HOLDING ITS GROUND...OR
SHOULD SAY OCEAN SURFACE...OVER THE WESTERN ATLANTIC. THE
MERIDIONAL FLOW HAS A DISTINCT POSITIVE TILT ACROSS THE UNITED
STATES...WHICH ALLOWS THE ATLANTIC TROUGH TO JUST SLOWLY SHEAR
APART IN PLACE...OR DRIFTING SOUTHWARD WITH TIME. THE ECENS MEAN
IS STILL PERFORMING STRONGLY ENOUGH AT THE DAY 6 TO 7 TIME RANGE
TO RELY ON ITS VERSION OF THE ATMOSPHERE OVER THE OTHER GUIDANCE.
FINAL...
NO SURPRISES WITH THE 12Z GUIDANCE...WITH THE PATTERN ILLUSTRATED
BY THE UPDATED MANUAL PROGS STILL SUPPORTED BY BOTH THE
DETERMINISTIC AND ENSEMBLE MEANS FROM THE VARIOUS CENTERS.
COORDINATED THE LOW DRIFTING WESTWARD ACROSS THE NORTHERN GULF OF
MEXICO WITH TPC DURING THE MIDDAY CALL...AS SUCH CIRCULATIONS
BREAKING OFF FRONTAL ZONES DO BECOME TROPICAL FROM TIME TO TIME.
HOW FAR OFF THE MID ATLANTIC COAST THE SYNOPTIC LOW ENDS UP
FORMING IS STILL UNCERTAIN...BUT HAVE THE POWER OF THE HIGHLY
RESOLVED ECENS MEAN MEMBERS TO BACK UP THE FINAL MANUAL DEPICTION
Read this earlier. I think it's not too impressed with the upcoming trough?
come in view now.
redwagon-I dont understand that last model/map-is it just showing the direction a storm would follow to get into the gulf?
ukm 60hr
it looks like i see 3 lows
The spin over central Africa is a doosy...wow.
48hr ukm
----------
You just take all the storms that ever hit TX, rewind them back to the Cape Verde (if you're analyzing CV storms, not Campeche or Caribbean), and see where they generated.
This low is currently at ~45% chance of coming to TX, per history.
Night!
Yep
hmm more west
We do??? :)
Something to keep an eye on..Western Caribbean
,ECMWF much slow move
Okay thanks!!!
Hang in there xcool. :)
Night. :)
Looking at what the latest GFS shows at 144 hours....
G'morning WU-Bloggers, lifts cuppa coffee to all points of the globe.
Ike those are too far east to generate my happy wave action.
Viewing: 1901 - 1951
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