Post Tropical Cristobal

[Srain]

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 24th day of the month at 11:48Z
Corrected: This observation corrected a previous observation.
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 303)
Tropical Depression: Number 4 (flight in the North Atlantic basin)
Mission Number: 6
Observation Number: 14
A. Time of Center Fix: 24th day of the month at 11:06:40Z
B. Center Fix Coordinates: 22°58'N 72°57'W (22.9667N 72.95W)
B. Center Fix Location: 156 miles (251 km) to the NW (312°) from Cockburn Town, Turks and Caicos Islands (GBR).
C. Minimum Height at Standard Level: Not Available
D. Estimated (by SFMR or visually) Maximum Surface Wind: 34kts (~ 39.1mph)
E. Location of the Estimated Maximum Surface Wind: 65 nautical miles (75 statute miles) to the NE (48°) of center fix
F. Maximum Flight Level Wind Inbound: From 158° at 39kts (From the SSE at ~ 44.9mph)
G. Location of Maximum Flight Level Wind Inbound: 76 nautical miles (87 statute miles) to the NE (48°) of center fix
H. Minimum Sea Level Pressure: 1001mb (29.56 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 23°C (73°F) at a pressure alt. of 364m (1,194ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 24°C (75°F) at a pressure alt. of 363m (1,191ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 23°C (73°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Wind, Pressure and Temperature
N. Fix Levels (sfc and flt lvl centers are within 5nm of each other): Surface and 1,500 feet
O. Navigational Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 6 nautical miles
Remarks Section:
Maximum Flight Level Wind: 49kts (~ 56.4mph) which was observed 67 nautical miles (77 statute miles) to the ESE (107°) from the flight level center at 10:15:30Z
Maximum Flight Level Wind Outbound: 41kts (~ 47.2mph) which was observed 57 nautical miles (66 statute miles) to the SSE (149°) from the flight level center at 11:28:30Z
Sea Level Pressure Extrapolation From: Below 1,500 feet
 

[MJO812]

The new 12z cane models all have this storm staying OTS. This threat is most likely a done deal.

[hawkeye_wx]

This system made too much northward progress yesterday and too little westward, so up and out to sea it goes.  The left-turning model runs pretty much all had it tracking wnw up the Bahama chain or even south of it.  It's amazing how difficult it has become for tropical systems to continue moving w/wnw into Florida.  For the last eight years there has always been a trough in place ready to turn systems north/northeast.

 

This morning's visible loop shows a storm that continues to be disorganized.  I think it was actually easier to find the exact center yesterday.  Today the circulation appears to be elongated nnw to sse.

[Srain]

TROPICAL STORM CRISTOBAL DISCUSSION NUMBER   4
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL042014
1100 AM EDT SUN AUG 24 2014

The overall cloud pattern of Cristobal has changed little since
the previous advisory. Flight-level wind data from the Air Force
Reserve and NOAA reconnaissance aircraft investigating Cristobal
earlier this morning indicated that the low-level and mid-level
circulations were not vertically aligned, suggesting that the
inner-core wind field of the cyclone is still trying to form. The
initial intensity of 40 kt is based on 1000-ft flight-level winds of
49 kt and a few reliable SFMR winds of near 40 kt.

The initial motion is an uncertain 345/6 kt. There are significant
differences noted between the various NHC models. The GFS model and
the GFS ensemble mean shear the mid-level circulation southward from
the current position, and take the remaining shallow and weak
low-level circulation quickly northeastward, which seems unlikely at
this time given the overall large structure of the cyclone noted in
recon, satellite, and upper-air data. In contrast, the ECMWF, UKMET,
and NAVGEM models keep Cristobal as a deeper, stronger, and more
vertically coherent cyclone, moving the system only slowly
north-northwestward or northwestward for the next 72 hours or so as
a strong mid-latitude trough over the Carolinas lifts out to the
northeast. As the trough lifts out, the subtropical ridge is
expected to build back in to the north of Cristobal until a second
trough moves off the U.S. east coast in 4-5 days and weakens the
ridge again, allowing Cristobal to move slowly northward and then
accelerate off to the northeast. More weight has been placed the on
the ECMWF-UKMET-NAVGEM solutions, and the official forecast track
remains near the left side of the guidance envelope.

Light to moderate northwesterly to northerly shear is expected to
affect Cristobal throughout the forecast period. However, the shear
is not forecast to be strong enough to prevent at least slow
strengthening, especially given that the upper-level flow is
expected to be quite diffluent and divergent through at least 48
hours, which will act to enhance convective development. The NHC
intensity forecast remains close to SHIPS guidance.

FORECAST POSITIONS AND MAX WINDS

INIT  24/1500Z 23.6N  73.1W   40 KT  45 MPH
12H  25/0000Z 24.2N  73.4W   45 KT  50 MPH
24H  25/1200Z 24.9N  73.6W   50 KT  60 MPH
36H  26/0000Z 25.7N  73.8W   55 KT  65 MPH
48H  26/1200Z 26.6N  74.1W   60 KT  70 MPH
72H  27/1200Z 29.3N  74.9W   65 KT  75 MPH
96H  28/1200Z 32.2N  73.3W   70 KT  80 MPH
120H  29/1200Z 35.0N  67.3W   75 KT  85 MPH

$$
Forecaster Stewart

 

 

[Eskimo Joe]

What a waste of a storm. Convection continues to fire on the eastern side which all but seals its fate.

[Srain]

G-IV mission plots for today.

 

[Kory]

Looks like the mid level vorticity is displaced a bit further south from the low level vorticity.  Could we possibly see a center relocation to the south where the MLC appears to be.  

 

 

[Srain]

Drifting N to NNW since the last VDM at 11:30Z from the NOAA P-3 and it is not vertically stacked. You could see the entire structure of the storm change earlier this morning via Rapid Scan 1KM visible imagery.

 

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 24th day of the month at 18:06Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 305)
Storm Number & Year: 04L in 2014
Storm Name: Cristobal (flight in the North Atlantic basin)
Mission Number: 8
Observation Number: 05
A. Time of Center Fix: 24th day of the month at 17:47:50Z
B. Center Fix Coordinates: 24°12'N 72°46'W (24.2N 72.7667W)
B. Center Fix Location: 294 miles (473 km) to the ESE (102°) from Nassau, Bahamas.
C. Minimum Height at Standard Level: 1,437m (4,715ft) at 850mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 42kts (~ 48.3mph)
E. Location of the Estimated Maximum Surface Wind: 88 nautical miles (101 statute miles) to the SSE (159°) of center fix
F. Maximum Flight Level Wind Inbound: From 213° at 39kts (From the SSW at ~ 44.9mph)
G. Location of Maximum Flight Level Wind Inbound: 112 nautical miles (129 statute miles) to the SSE (153°) of center fix
H. Minimum Sea Level Pressure: 1001mb (29.56 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 17°C (63°F) at a pressure alt. of 1,465m (4,806ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 21°C (70°F) at a pressure alt. of 1,455m (4,774ft)
K. Dewpoint Temp & Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Level: 850mb
O. Navigational Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 10 nautical miles
Remarks Section:
Maximum Flight Level Wind: 39kts (~ 44.9mph) which was observed 112 nautical miles (129 statute miles) to the SSE (153°) from the flight level center at 17:10:00Z
 

[Srain]

Latest AF and NOAA RECON vortex messages suggest that the center of Cristobal is nearly stationary. The trough looks like it will miss the disorganized storm and a general drift should develop until mid week until the next trough across the Mid West finally lifts it out to the N and E.

[wxmeddler]

Latest AF and NOAA RECON vortex messages suggest that the center of Cristobal is nearly stationary. The trough looks like it will miss the disorganized storm and a general drift should develop until mid week until the next trough across the Mid West finally lifts it out to the N and E.

 

I would almost even say that the sfc circulation is stretched or moving SSE due to the intense thunderstorm activity. One thing that's notable about the G-IV mission is that the outflow/exhaust was stronger to the S and SE and non-existant to the N/NW, really helping those thunderstorm grow in that SE quad.

[stormspotterlive]

I would almost even say that the sfc circulation is stretched or moving SSE due to the intense thunderstorm activity. One thing that's notable about the G-IV mission is that the outflow/exhaust was stronger to the S and SE and non-existant to the N/NW, really helping those thunderstorm grow in that SE quad.

Yeah the Latest Loop would suggest a Possible SSE movement.

[ineedsnow]

Most models pick it up soon guess we will know soon enough

[dan88]

From Recon, just got to the center

55kt flight level (850mb) winds

47kt SFMR

996.2mb extrap

850MB Center roughly 24.2N, 72.8W

 

Edit

000URNT12 KNHC 250553VORTEX DATA MESSAGE   AL042014A. 25/05:31:30ZB. 24 deg 11 min N  072 deg 48 min WC. 850 mb 1398 mD. 47 ktE. 102 deg 40 nmF. 195 deg 55 ktG. 112 deg 59 nmH. 996 mbI. 17 C / 1523 mJ. 21 C / 1524 mK. 17 C / NAL. NAM. NAN. 1345 / 8O. 0.02 / 3 nmP. AF303 1004A CRISTOBAL          OB 04MAX FL WIND 55 KT 112 / 59 NM 05:06:00ZCNTR DROPSONDE SFC WIND 130 / 14 KT;

[Srain]

Cristobal strengthen a bit overnight and pressures dropped slightly to 994mb as indicated by RECON. The 'center' of Cristobal did relocate SE closer to the deeper convection, but N to NW shear has taken a toll on the overall structure. Shear is expected to relax later today as the trough lifts out and a slow N to NNE motion begins. Cristobal poses no threat to the US Mainland, but is expected to pass W and NW of Bermuda later this week as the next trough picks up Cristobal and excellerates NE as a 80 to 85 MPH Hurricane before transitioning to a extratropical storm in the N Atlantic.

[AutoPenalti]

Naked swirl alert.

[deltadog03]

Color me not impressed with Cristobal.  Nice 994/995mb LLC, just naked from the pounding northerly shear.  I just not sure how much stronger this can get.  Maybe once its between NC and Bermuda?

[Juliancolton]

Barring significant changes in the cyclone's structure, this will be the third consecutive usage of the name Cristobal for a weak, disorganized TS off the US East Coast. Funny how that works sometimes.

[phil882]

Kudos to the NOAA P3 crew that just flew through some -90C tops on the downshear side of Christobal... looks like there might be a developing protovortex that could become the new center if the convection remains persistent. Check out the 6-8 hPa pressure drop coinciding with a 65-70 knot flight level winds (SFMR also in the 65-70 knot range although they are rain contaminated).

 

 

[Superstorm93]

Intense lightning within that region of -85C tops. 

 

Vortex tilting due to the northerly shear is really sparking this up:

 

[N. OF PIKE]

Kudos to the NOAA P3 crew that just flew through some -90C tops on the downshear side of Christobal... looks like there might be a developing protovortex that could become the new center if the convection remains persistent. Check out the 6-8 hPa pressure drop coinciding with a 65-70 knot flight level winds (SFMR also in the 65-70 knot range although they are rain contaminated).

 

 

 

Phil, hypothetically if that new area you mentioned becomes the center,what direction/distance relocation would that be approx. i.e 50 miles SE?

[phil882]

Intense lightning within that region of -85C tops. 

 

Vortex tilting due to the northerly shear is really sparking this up:

 

 

Noaa P3 VDM concurs. Winds are also up to 70mph in the intermediate advisory.

 

000

URNT12 KWBC 252344 CCA

VORTEX DATA MESSAGE AL042014

A. 25/23:28:16Z

B. 25 deg 01 min N

071 deg 57 min W

C. NA

D. 71 kt

E. 173 deg 33 nm

F. 253 deg 73 kt

G. 178 deg 29 nm

H. 990 mb

I. 15 C / 2352 m

J. 19 C / 2409 m

K. 14 C / NA

L. NA

M. NA

N. 12345 / NA

O. 1 / 2 nm

P. NOAA3 1304A CRISTOBAL OB 15 CCA

MAX FL WIND 73 KT 178 / 28 NM 23:20:10Z

CNTR DROPSONDE SFC WIND 210 / 15 KTS

FRQ LTG SE QUAD

[Ginx snewx]

Hurricane

[phil882]

Phil, hypothetically if that new area you mentioned becomes the center,what direction/distance relocation would that be approx. i.e 50 miles SE?

 

If we are talking hypotheticals here, the NOAA P3 identified the true vortex center of Christobal at 25.0N 71.9W. The minimum SLP associated with the mesovortex discussed above was located at 24.5N 71.9W, so approximately 55 km due S. What typically happens is that the two features discussed are undergoing binary interaction (in the assumption that you are looking at two barotropic circulations) so that the flow from each circulation imparts motion on the other.

 

In many cases the mesovortex merges with the parent vortex, which "pulls" the parent vortex closer to where the mesovortex originated due to the interacting flows. In other cases, the mesovortex is strong enough that it "absorbs" the weaker parent vortex and becomes the new center, which can result in a significant center relocation. A 6-8 hPa pressure drop relative to the parent vortex is rather significant, and if the deeper convection can remain persistent, it could become the dominant vortex. Unfortunately the NOAA-P3 has completed its mission, so we won't be able to have in-situ data that will confirm this. Maybe we can get lucky with a few microwave passes overnight.

 

This is really an oversimplification of the dynamical processes that can occur with sheared TCs, but its probably not unlike the processes that lead to the initial intensification of TC Arthur in July, and TC Bertha earlier this month. 

[wxtrackercody]

It sure doesn't look the part, but recon found the evidence...

 

HURRICANE CRISTOBAL TROPICAL CYCLONE UPDATE
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL042014
820 PM EDT MON AUG 25 2014

...CRISTOBAL BECOMES A HURRICANE...

REPORTS FROM A NOAA HURRICANE HUNTER AIRCRAFT INDICATE THAT
CRISTOBAL HAS STRENGTHENED INTO A HURRICANE.  THE MAXIMUM WINDS ARE
ESTIMATED TO BE 75 MPH...120 KM/H...WITH HIGHER GUSTS.

SUMMARY OF 820 PM EDT...0020 UTC...INFORMATION
--------------------------------------------------
LOCATION...25.0N 71.9W
ABOUT 660 MI...1065 KM SW OF BERMUDA
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...E OR 100 DEGREES AT 2 MPH...4 KM/H
MINIMUM CENTRAL PRESSURE...990 MB...29.23 INCHES

$$
FORECASTER PASCH

[phil882]

Hurricane

 

Yea back to back dropsondes contained > 65 knot winds in the lowest 150 gpm

 

Transmitted: 26th day of the month at 00:01Z

 

Average Wind Over Lowest Available 150 geopotential meters (gpm) of the sounding:

- Lowest 150m: 159 gpm - 9 gpm (522 geo. feet - 30 geo. feet)

- Wind Direction: 185° (from the S)

- Wind Speed: 70 knots (81 mph)

 

Transmitted: 26th day of the month at 00:04Z

 

Average Wind Over Lowest Available 150 geopotential meters (gpm) of the sounding:

- Lowest 150m: 158 gpm - 8 gpm (518 geo. feet - 26 geo. feet)

- Wind Direction: 185° (from the S)

- Wind Speed: 66 knots (76 mph)

 

[PSUBlizzicane2007]

Well I can't say I expected that today

[Superstorm93]

Would love to be on a high-altitude flight and see the lightning in this thing. 

 

ETLN is showing "continuous" lightning on some of the overshooting tops 

 

[EasternUSWX]

Convection blowing up last few hours. Probably going to see a pretty nice looking storm, too bad it is going OTS.

 

[deltadog03]

I must admit, its looks much better right now.  looks like its def. trying to make a run.

[Kory]

Looks like a mid level eye is trying to peak out.