EPAC: TROPICAL DEPRESSION JIMENA (13E)

[HURAKAN]

Looking amazing

[Derek Ortt]

we've seen a definite left turn during the day today. Maybe there is stronger ridging to the north

[Kingarabian]

Looking amazing

It looks like a baby hurricane, doesnt it? Except it has a real bad attitude.

[I-wall]

Wow, I dont think i've ever seen a hurricane wobble as much as Jimena has in the last 6-7 hours. Are smaller hurricanes more prone to wobbles?

[Derek Ortt]

it hasnt really wobbled. It has turned from NW to WNW

[Aric Dunn]

if thats only 135 mph im must be slightly blind in one eye.. lol

maybe we can remember all those years ago of a hurricane named Wilma.. that sat estimates were only a mere 20 to 30 mph slower than what recon found that night when that finally to pass the 2-4 miles wide eye...

i that is a tiny eye and winds are likely higher ...

[CrazyC83]

if thats only 135 mph im must be slightly blind in one eye.. lol

maybe we can remember all those years ago of a hurricane named Wilma.. that sat estimates were only a mere 20 to 30 mph slower than what recon found that night when that finally to pass the 2-4 miles wide eye...

i that is a tiny eye and winds are likely higher ...

I do agree that Jimena is probably a high-end Cat 4 (almost Cat 5) right now. Unfortunately we'd never know for sure until Recon comes in tomorrow.

[HurricaneRobert]

They'll have their work cutout this year for underestimated hurricanes. Carlos was likely a Category 3, maybe 4.

[cycloneye]

000
WTPZ43 KNHC 302043
TCDEP3
HURRICANE JIMENA DISCUSSION NUMBER 9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP132009
200 PM PDT SUN AUG 30 2009

JIMENA CONTINUES TO HAVE A SMALL EYE EMBEDDED WITHIN A QUITE
SYMMETRIC CENTRAL DENSE OVERCAST. ON INFRARED IMAGES...THE EYE
TEMPERATURES HAVE WARMED SOMEWHAT...SUGGESTIVE OF ADDITIONAL
STRENGTHENING. SUBJECTIVE DVORAK T-NUMBERS REMAIN AT T 6.0 FROM
BOTH AGENCIES BUT OBJECTIVE T-NUMBERS SUPPORT A STRONGER HURRICANE
...PRIMARILY BECAUSE OF THE WARMER EYE. THEREFORE THE NHC INTENSITY
ESTIMATE IS BOOSTED TO 120 KT. ADDITIONAL STRENGTHENING IS
CERTAINLY A POSSIBILITY GIVEN THE WARM WATERS...LIGHT SHEAR...AND
MOIST TROPOSPHERE. HOWEVER...THE INTENSIFICATION PROCESS COULD ALSO
BE HALTED AT ANY TIME BY AN EYEWALL REPLACEMENT CYCLE. THE OFFICIAL
WIND SPEED FORECAST SHOWS ONLY A SLIGHT ADDITIONAL INCREASE IN
STRENGTH. BEGINNING AROUND 48 HOURS...THE GLOBAL MODELS SHOW
INCREASING SOUTHWESTERLY UPPER-LEVEL FLOW NEAR JIMENA. THE
RESULTING INCREASE IN SHEAR WILL PROBABLY LEAD TO A WEAKENING
TREND...AND THIS IS REFLECTED IN THE OFFICIAL FORECAST. ALSO BEYOND
48 HOURS...THE INTENSITY OF THE TROPICAL CYCLONE WILL BE DEPENDENT
ON HOW MUCH IT INTERACTS WITH LAND.

THERE HAVE BEEN SOME TROCHOIDAL WOBBLES...TYPICAL OF THE MOVEMENT OF
INTENSE HURRICANES...BUT THE SMOOTHED INITIAL MOTION ESTIMATE IS
ABOUT 295/07. THE FUTURE TRACK OF JIMENA SEEMS TO DEPEND LARGELY
UPON THE EVOLUTION OF TWO MAIN FACTORS...A MID- TO UPPER-LEVEL LOW
LOCATED NEAR THE SOUTHERN BAJA CALIFORNIA PENINSULA AND A MID-LEVEL
RIDGE OVER THE SOUTHWESTERN U.S. AND NORTHWESTERN MEXICO. IF THE
LOW SHIFTS WESTWARD AND WEAKENS...IT WOULD ALLOW THE RIDGE TO BUILD
WESTWARD AND COULD CAUSE THE TRACK TO VEER WESTWARD AWAY FROM BAJA.
THAT APPEARS TO BE THE SCENARIO DEPICTED BY THE U.K. MET. OFFICE
AND ECMWF GLOBAL MODELS. HOWEVER...THOSE MODELS ARE THE WESTERN
OUTLIERS OF THE DYNAMICAL TRACK GUIDANCE. OTHER GUIDANCE SUCH AS
THE GFS...THE HWRF...AND THE GFDL INDICATE THAT THE MID- TO
UPPER-LEVEL LOW WILL CONTINUE TO INFLUENCE THE MOVEMENT OF THE
HURRICANE...SO THAT JIMENA WILL CONTINUE TO TURN TOWARD THE
RIGHT...AND MOVE NEAR OR OVER BAJA. THE OFFICIAL FORECAST IS
SIMILAR TO THE PREVIOUS ONE AND IS CLOSE TO THE MIDDLE OF THE MODEL
TRACKS.

INTERESTS IN WESTERN MAINLAND MEXICO AND THE SOUTHERN BAJA
CALIFORNIA SHOULD MONITOR THE PROGRESS OF JIMENA. A HURRICANE WATCH
MAY BE REQUIRED FOR PORTIONS OF THE SOUTHERN BAJA CALIFORNIA
PENINSULA LATER TODAY OR TONIGHT.

FORECAST POSITIONS AND MAX WINDS

INITIAL 30/2100Z 16.6N 106.8W 120 KT
12HR VT 31/0600Z 17.3N 107.7W 125 KT
24HR VT 31/1800Z 18.7N 108.7W 125 KT
36HR VT 01/0600Z 20.6N 110.0W 125 KT
48HR VT 01/1800Z 22.6N 110.8W 115 KT
72HR VT 02/1800Z 26.5N 112.5W 75 KT...INLAND
96HR VT 03/1800Z 28.0N 114.0W 50 KT...INLAND
120HR VT 04/1800Z 28.5N 115.0W 25 KT

$$
FORECASTER PASCH

[CrazyC83]

Indeed they decided to go beyond the really conservative Dvorak estimate.

[bob rulz]

It looks like an EWRC could be starting...or is that just my inexperienced and untrained eye seeing things that aren't there?

[bahamaswx]

Did Jimena not just spit out an outflow boundary?

[Macrocane]

Did Jimena not just spit out an outflow boundary?

I was going to say that, and it seems to be a big one.

[Kingarabian]

What do you mean by outflow boundary?

[Macrocane]

I was going to tell you the definition with my own words but this is better:

An outflow bounday is A storm-scale or mesoscale boundary separating thunderstorm-cooled air (outflow) from the surrounding air; similar in effect to a cold front, with passage marked by a wind shift and usually a drop in temperature. Outflow boundaries may persist for 24 hours or more, and may travel hundreds of miles from their area of origin. New thunderstorms often develop along outflow boundaries, especially near the point of intersection with another boundary

[Kingarabian]

I was going to tell you the definition with my own words but this is better:

An outflow bounday is A storm-scale or mesoscale boundary separating thunderstorm-cooled air (outflow) from the surrounding air; similar in effect to a cold front, with passage marked by a wind shift and usually a drop in temperature. Outflow boundaries may persist for 24 hours or more, and may travel hundreds of miles from their area of origin. New thunderstorms often develop along outflow boundaries, especially near the point of intersection with another boundary

Okay thanks!

So what does this mean with Jimena?

[Macrocane]

I took this from another site:

Big outflow boundaries on Hurricane Luis (1995) were observed and this could have been the reason:
1) a period of moderately intense wind shear and dry air intrusion caused the eyewall convection to ingest dry midlevel air and weaken,
2) the collapsing convection produced a very stable Low-level thunderstorm outflow air mass ahead of itself,
3) the convection near the center of the hurricane passed over this stable, low-level air mass and weakened, a
nd 4) once out of this region, the storm reintensified.

So that could have been the case with Jimena too.

[Macrocane]

The feature in the red "circle" is what we've been talking about.

[Derek Ortt]

that is so far outside of the storm, hat it shouldn't have much of an impact

[Kingarabian]

The feature in the red "circle" is what we've been talking about.

Ahh I see. Kk thanks. It looks interesting...