Dr. Jeff Masters' WunderBlog

Quoting Grothar:

Interesting how the radar data just got lost after the storm moved over WFO Romeoville.

Quoting alfabob:
EPAC has developed an anti-cyclone around convection, up to 1% now.

Waning convection, high shear and models forming the system at 72hrs out seems to have reduced the probability of formation within 24hrs in the SW carib.

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
100 PM CDT SUN MAY 29 2011

ILC091-291815-
/O.CON.KLOT.TO.W.0013.000000T0000Z-110529T1815Z/
KANKAKEE IL-
100 PM CDT SUN MAY 29 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR KANKAKEE COUNTY UNTIL 115
PM CDT...

God, the thunder is loud where I am.

Quoting xcool:
i wait for 18z cmc models

The CMC only runs twice: at 0z, and at 12z.

Quoting 7080734:
God, the thunder is loud where I am.

I couldn't help but notice the 708 in your username, you live in Chicago area also?

Quoting MrstormX:


I couldn't help but notice the 708 in your username, you live in Chicago area also?

Yup. I messed up making my username somehow.

Upgraded to moderate risk along the Bow Echo.


Discussion

SPC AC 291619

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1119 AM CDT SUN MAY 29 2011

VALID 291630Z - 301200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER NORTHERN IL...NORTHERN
IND...AND SOUTHERN LOWER MI...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SOUTHERN HIGH
PLAINS...INTO THE UPPER MIDWEST...AND EASTWARD TO WESTERN NEW
ENGLAND...

...IL TO LOWER MI...
A WELL-DEVELOPED BOW ECHO HAS FORMED THIS MORNING OVER NORTHEAST IL.
THIS CONVECTIVE COMPLEX IS EXPECTED TO TRACK EAST-NORTHEASTWARD
ALONG RETREATING WARM FRONT INTO PORTIONS OF IND AND LOWER MI BY
EARLY EVENING. ALTHOUGH THERE DOES NOT APPEAR TO BE A STRONG UPPER
SHORTWAVE TROUGH ASSOCIATED WITH THE STORMS...STRONG WESTERLY FLOW
ALOFT AND AMPLE INSTABILITY SUGGEST THE POTENTIAL FOR A LONG-LIVED
BOW AND RESULTING DERECHO EVENT. THEREFORE...HAVE UPGRADED TO
MODERATE RISK IN THIS REGION.

Quoting 7080734:
God, the thunder is loud where I am.

This could be why. Scary link


Link

Funnel Cloud spotted in Kankakee.

KoritheMan .00Z; 06Z; 12Z; 18Z. CMC

Hold on, folks... bumpy ride ahead...

Hour 72 12Z ECMWF.....

72 H looks bad for us

CARIBBEAN SEA...
THE UPPER TROUGH OVER THE W ATLC COVERING THE E GULF OF MEXICO
EXTENDS ACROSS W CUBA TO OVER THE FAR NW CARIBBEAN WITH DRY
STABLE AIR OVER THE NW CARIBBEAN W OF LINE FROM E CUBA NEAR
21N78W TO BELIZE NEAR 17N88W. THE REMAINDER OF THE CARIBBEAN IS
DOMINATED BY AN UPPER RIDGE ANCHORED ALONG THE COAST OF
VENEZUELA NEAR 65W. A SURFACE TROUGH REMAINS IN THE SW CARIBBEAN
EXTENDING FROM 13N77W TO COSTA RICA NEAR 10N83W. SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 75/90 NM OF LINE FROM
12N72W 13N79W TO 15N83W. SCATTERED SHOWERS/THUNDERSTORMS ARE
WITHIN 90 NM ALONG THE COAST OF S NICARAGUA FROM THE BORDER OF
COSTA RICA TO 13N. DIFFLUENT FLOW ALOFT COMPLIMENTS OF THE UPPER
RIDGE IS GIVING THE CENTRAL CARIBBEAN DENSE CLOUD COVER WITH
ISOLATED SHOWERS W OF THE DRY AIR OVER THE NW CARIBBEAN TO 68W.
WINDS WILL INCREASE OVER THE CENTRAL AND E CARIBBEAN THROUGH WED
BETWEEN DEVELOPING LOW PRESSURE OVER THE SW CARIBBEAN AND
SURFACE RIDGE OVER THE W ATLC. THE TROPICAL WAVE ALONG 60W WILL
CONTINUE TO MOVE ACROSS THE WINDWARD ISLANDS THIS AFTERNOON AND
TONIGHT.

ATLANTIC OCEAN...
A HIGHLY AMPLIFIED UPPER TROUGH EXTENDS FROM 31N59W WSW ALONG
28N72W ACROSS THE N BAHAMAS TO THE STRAITS OF FLORIDA AND THE N
COAST OF CUBA NEAR HAVANA.

IOW, doesn't sound like much doing today.... maybe tomorrow.

Levi, after the upgrades that some of the models have been thru recently,which model in your estimation will be the stellar one this season?

I wonder if the 'drought' in Florida has to do with the transition from La Nina to neutral conditions in the tropics.

Quoting wunderkidcayman:
72 H looks bad for us

Please don't tell me that they actually have the cmc on their minds.

Blog update.

Tropical Tidbit for Sunday, May 29th, with video

On the CMC, I think it's performance is much improved over earlier years.... and a hurricane is not out of the realm of the possible even early in Jun. OTOH, it certainly does seem very unlikely given current conditions....

Quoting Tropicsweatherpr:
Levi, after the upgrades that some of the models have been thru recently,which model in your estimation will be the stellar one this season?

I still think the ECMWF is king, though I will hope for better performances from the GFS this year due to its upgrades.

Quoting rmbjoe1954:
I wonder if the 'drought' in Florida has to do with the transition from La Nina to neutral conditions in the tropics.

Likely enough.

Quoting wunderkidcayman:
72 H looks bad for us

Very interesting to note the forecast progression of the high over the SE US.

Quoting BahaHurican:
On the CMC, I think it's performance is much improved over earlier years.... and a hurricane is not out of the realm of the possible even early in Jun. OTOH, it certainly does seem very unlikely given current conditions....

Think about it man. A hurricane sitting on top of us for a couple of days strengthening. That would be one of the worst disasters in human history. Do you know what the highest point on grand cayman is? 50 feet.

120 hours.....

Quoting Bitmap7:


Waning convection, high shear and models forming the system at 72hrs out seems to have reduced the probability of formation within 24hrs in the SW carib.

there was no probability of formation the SW Caribbean in 24 hours

With the historical average of about 1-2 storms spinning up in all of June/July, if this storm did materialize this early on, it would actually be a good wake-up call for folks to have preparations in place for the rest of the season....

Quoting Bitmap7:


Think about it man. A hurricane sitting on top of us for a couple of days strengthening. That would be one of the worst disasters in human history. Do you know what the highest point on grand cayman is? 50 feet.

Grand Cayman, the largest of the three islands, has an area of about 76 square miles and is approximately 22 miles long with an average width of four miles. Its most striking feature is the shallow, reef-protected lagoon, the North Sound, which has an area of about 35 square miles. The island is low-lying, with the highest point about 60 feet above sea level.

Quoting Hurricanes101:


there was no probability of formation the SW Caribbean in 24 hours

There was yesterday. They had the light blue in that spot.

Quoting Bitmap7:


There was yesterday. They had the light blue in that spot.

I never put much stock in that map

Quoting stormwatcherCI:
Grand Cayman, the largest of the three islands, has an area of about 76 square miles and is approximately 22 miles long with an average width of four miles. Its most striking feature is the shallow, reef-protected lagoon, the North Sound, which has an area of about 35 square miles. The island is low-lying, with the highest point about 60 feet above sea level.

Close enough just 10 feet off. Still is a pretty serious situation with the cmc's scenario even if its 10ft higher than I stated. That point is also likely to be a small area in the shrubs of east end.

144 hours:

Quoting Bitmap7:


Think about it man. A hurricane sitting on top of us for a couple of days strengthening. That would be one of the worst disasters in human history. Do you know what the highest point on grand cayman is? 50 feet.

Yah, got to admit u guys are lower than us on New Providence, but not by much.... and I can tell u having a hurricane develop over ur head is rather.... shall we say, DISCONCERTING??? Happened here with Katrina in '05.... that morning clear skies and a TD passing through... no biggie.... that afternoon, TS Katrina strengthening all the way from Exuma to Miami, right overhead.... Trying to get home from work in the heavy localized flooding was an experience I'm not likely to forget...

>

Tighter by 168; It will probably deepen some more by the end of the run. It's also trapped under that ridge again, moving WNW.

Quoting JMasters (above)

"Up until now, wind shear has been too high to allow tropical storm formation in the Caribbean, due to the presence of the Subtropical Jet Stream. However, this jet is expected to push northwards over Cuba over the coming week, allowing a region of low wind shear to develop over most of the Caribbean".

Notice the Shear jet moving northwards Cuba

The NAEFS is also still confused. The ensemble spread (shaded colors) shows three possible locations for our tropical system by Day 7, illustrated by the pink blobs. One southeast of Texas (yay?), one near western Cuba, and one north of Puerto Rico. Given the size of the eastern U.S ridge and the trough over California, I think this last possibility is becoming the least likely.

Quoting sunlinepr:
Quoting JMasters (above)

Up until now, wind shear has been too high to allow tropical storm formation in the Caribbean, due to the presence of the Subtropical Jet Stream. However, this jet is expected to push northwards over Cuba over the coming week, allowing a region of low wind shear to develop over most of the Caribbean.

Notice the Shear jet moving northwards Cuba

Very important to note what's now occurring in the SW Atlantic over the Bahamas. Now starting to see the evolution of the upper level low cutting off from the upper trough across the Atlantic. This will play a crucial role in what will happen in the coming week.

12z ECMWF Day 8 shows a deepening tropical depression with its neighboring upper low northwest of it over the Gulf of Mexico. The orientation of the 500mb ridge north of it hints at the possibility of it being gulf-bound.

Mimicking the 12z CMC...just weaker.

By Day 9, a tropical storm:

Quoting Levi32:
The NAEFS is also still confused. The ensemble spread (shaded colors) shows three possible locations for our tropical system by Day 7, illustrated by the pink blobs. One southeast of Texas (yay?), one near western Cuba, and one north of Puerto Rico. Given the size of the eastern U.S ridge and the trough over California, I think this last possibility is becoming the least likely.

Starting to think the Gulf region may be coming more into play, but it remains speculation for now.

Quoting Levi32:
12z ECMWF Day 8 shows a deepening tropical depression with its neighboring upper low northwest of it over the Gulf of Mexico. The orientation of the 500mb ridge north of it hints at the possibility of it being gulf-bound.

Its amazing how just this time yesterday we saw the chances of something entering the Gulf as very unlikely

What was the most likely scenario (NE towards the islands), is now becoming the unlikely scenario

Just as anecdotal information, winds have been quite fresh here all day... most recently out of the N....

Quoting Levi32:
By Day 9, a tropical storm:

The lowering heights over the system suggest a more conducive environment for strengthening developing with time.

Quoting Hurricanes101:


Its amazing how just this time yesterday we saw the chances of something entering the Gulf as very unlikely

What was the most likely scenario (NE towards the islands), is now becoming the unlikely scenario

Not really, actually. The gulf scenario was there but only for the long-term. Yesterday, most of the models had the thing developing and scooting out of the Caribbean by Day 5 and 6. I mentioned that the gulf would be possible if it stayed there for 8-10 days, but the majority of the models weren't showing that. Today, however, they are, and now the gulf seems open.

afternnon everyone...I ask this earlier but, Ive noticed how the SOI has crashed the past feww weeks,,,down to +2.0 and that cloudiness near the dateline has increased as well..could that be pointing towards a developing El Nino?? I know most models show neutral conditions through the summer any input on this?? Thanks