Tropical Remnant Chantal

[Marion_NC_WX]

Are the Hurricane Hunters still scheduled for this afternoon?

[Superstorm93]

Are the Hurricane Hunters still scheduled for this afternoon?

 

Wheels just went up at 2:30 

[metalicwx366]

Are the Hurricane Hunters still scheduled for this afternoon?

Yep, they just departed.

[phil882]

Nice twist in the 12z GFS ... landfall near Daytona Beach, and then west to wsw into the GoM, 2nd landfall near the LA/TX border. Trough misses Chantal and strong ridging building for most of the CONUS east of the Rockies. Then a 2nd cyclone heading for the GoM as well, and a third in the Caribbean.

 

A very interesting solution, but its obviously a very low confidence forecast depending on the fate of Chantal after Hispaniola. The strength of Chantal in the next 48 hours is going to be pivotal in its eventual survival beyond the Greater Antilles. If its remains at its current organizational appearance then it almost certainly will not survive. We need a stronger and also larger system to increase those odds.

 

 

Not bad looking right now. 

 

It actually somehow managed to develop convection over the center once again. 

 

2013AL03_1KMSRVIS_201307081545.GIF

 

But note the CDO convection is focused east of the llc still. Looking at the storm relative visible loop, you can see the cirrus shield associated with the convection is streaming off to the east of the llc indicative of westerly vertical wind shear. The storm is certainly fighting the strong low-level flow right now, and the upper-level flow despite being the same orientation is having trouble keeping up. 

[phil882]

Yep, they just departed.

 

Should be an interesting mission... particularly interested in how much westerly flow they find south of the llc. 

[Superstorm93]

That westward turn is getting more pronounced. That could be quite interesting if it's still alive...

 

 

18z 

 

 

12z GFDL Ensembles with intensity 

 

[wxmeddler]

But note the CDO convection is focused east of the llc still. Looking at the storm relative visible loop, you can see the cirrus shield associated with the convection is streaming off to the east of the llc indicative of westerly vertical wind shear. The storm is certainly fighting the strong low-level flow right now, and the upper-level flow despite being the same orientation is having trouble keeping up. 

 

You can see this clearly in this loop here, Chantal is too fast for her own good.

[Jim Marusak]

how much slower would she have to be to get things together, best guess? down to about 15kt forward speed from its current 25?

[phil882]

how much slower would she have to be to get things together, best guess? down to about 15kt forward speed from its current 25?

 

That sounds about right... recon is still flying at 375 hPa right now, and the flow is basically easterly between 20-25 knots. Unfortunately that's the same speed as the storm currently, which is why you don't see expanding outflow in the western quadrant. Instead, the western quadrant of the storm looks sickly, with evidence of cold downdrafts from the popcorn convection in the NW infiltrating the inner core. This may be responsible for the increased the separation between the center and the CDO feature that was present with the llc earlier today. We are probably at the diurnal minima for convection in this portion of the Atlantic basin, so there may be an attempt for convection to redevelop tonight, but that will only be useful for development if the convection wraps into the center like it attempted to do last night. 

[phil882]

Again there are many parallels to Ernesto which battled the same strong low-level flow in the first 24-48 hours of its lifespan.

 

Ernesto 1845 UTC 2 Aug

 

 

 

Chantal 1845 UTC 8 Jul

 

[wxsouth]

Again there are many parallels to Ernesto which battled the same strong low-level flow in the first 24-48 hours of its lifespan.

 

Ernesto 1845 UTC 2 Aug

 

 

 

Chantal 1845 UTC 8 Jul

 

 

 

I agree with the comparison with Ernesto in regards to the fast low-level flow. However, the biggest difference in those two images is the lack of substantial arc clouds with Chantal (to this point). This suggests a more moist atmosphere for Chantal vs. Ernesto which may help to sustain the convection a bit better.  In fact, the recon dropsonde on the inbound leg is very moist below 500mb, so Chantal appears to be embedded within a decent moist pouch.

[dan88]

Going to have some degree of communication problems with recon this mission, last few sets of obs were several minutes late, and still waiting on a set now about 10 minutes late.

[wxmeddler]

That's a bit of a surprise, only 1010.0 mb. Looks like we have west winds too, but only <10kt FL (960mb). This is really more of a wave then a true TS.

[metalicwx366]

Apparently the lowest pressure is 1010mb so far.

[phil882]

I agree with the comparison with Ernesto in regards to the fast low-level flow. However, the biggest difference in those two images is the lack of substantial arc clouds with Chantal (to this point). This suggests a more moist atmosphere for Chantal vs. Ernesto which may help to sustain the convection a bit better.  In fact, the recon dropsonde on the inbound leg is very moist below 500mb, so Chantal appears to be embedded within a decent moist pouch.

 

Good point, there really hasn't been any obvious indications of arc clouds. Unfortunately, it looks like the circulation of Chantal is pretty fragile... only a 1010 hPa minimum pressure so far, with the strongest west winds in the S quadrant only in the 5-10 knot range. Its closed, but only barely.

[phil882]

On a more positive note, the possible center is trying to get some cells to wrap around on the NE quadrant near 12N and 54W. The center is a little further south (or elongated since the NE hasn't been sampled yet) than expected based on the low-level cloud motions alone. 

 

[wxmeddler]

Ha, great timing by the NOAA-17 Microwave pass. The microwave image, the goes IR and the Hurricane Hunter obs are all within 10 min of each other.

[phil882]

Ha, great timing by the NOAA-17 Microwave pass. The microwave image, the goes IR and the Hurricane Hunter obs are all within 10 min of each other. GE_2013-07-08_2125.PNG

 

Nice overlay... it seems that overshooting top on the visible still above your post may in fact be an attempt at convective activity wrapping around the northern portion of the circulation. Thats a more impressive microwave presentation than I was expecting given the 1010 hPa pressure. 

[metalicwx366]

Latest Full resolution GFS has Chantal at 995mb off the FL/GA coast. Much stronger run than before. Also you can clearly see Dorian on the map.

http://www.tropicaltidbits.com/analysis/models/gfsfull/2013070818/gfsfull_pres_wind_atltropics_49.png

[wxmeddler]

60 kt uncontaminated SFMR in the NW Quad. LOL. That forward speed is just messing with it, and the weenies!

[phil882]

60 kt uncontaminated SFMR in the NW Quad. LOL. That forward speed is just messing with it, and the weenies!

 

lol. It is rain contaminated though (28 mm/hr). Max flight level winds were 58 knots with max SFMR under 10mm/hr at 44 knots. Its probably a 45-50 knot storm currently based on wind alone, although the circulation is barely closed per the last pass.

[Superstorm93]

Adjusted winds could probably put this at 50mph 

 

[Guest Imperator]

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 8th day of the month at 23:07Z
Corrected: This observation corrected a previous observation.
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 302)
Storm Number & Year: 03L in 2013
Storm Name: Chantal (flight in the North Atlantic basin)
Mission Number: 1
Observation Number: 10
A. Time of Center Fix: 8th day of the month at 22:27:40Z
B. Center Fix Coordinates: 11°38'N 54°34'W (11.6333N 54.5667W) (View map)
B. Center Fix Location: 355 miles (572 km) to the ESE (107°) from Bridgetown, Barbados.
C. Minimum Height at Standard Level: Not Available
D. Estimated (by SFMR or visually) Maximum Surface Wind: 27kts (~ 31.1mph)
E. Location of the Estimated Maximum Surface Wind: 25 nautical miles (29 statute miles) to the ESE (115°) of center fix
F. Maximum Flight Level Wind Inbound: From 179° at 29kts (From the S at ~ 33.4mph)
G. Location of Maximum Flight Level Wind Inbound: 28 nautical miles (32 statute miles) to the ESE (116°) of center fix
H. Minimum Sea Level Pressure: 1011mb (29.85 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 20°C (68°F) at a pressure alt. of 395m (1,296ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 22°C (72°F) at a pressure alt. of 392m (1,286ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 22°C (72°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, Radar, Wind, Pressure and Temperature
N. Fix Level: 1,500 feet
O. Navigational Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 9 nautical miles
Remarks Section - Remarks That Were Decoded...
Sea Level Pressure Extrapolation From: Below 1,500 feet
Maximum Flight Level Temp: 22°C (72°F) which was observed 11 nautical miles (13 statute miles) to the ESE (106°) from the flight level center
Remarks Section - Additional Remarks...
MAX OUTBOUND AND MAX FL WIND 58 KT 042/37 22:39:30Z
MIN SLP 1010 MB 042/21NM FROM FLT LEVEL CTR

[phil882]

Useful radar to be looking at as the storm rapidly approaches:

 

 

Speaking of rapid... the storm gained about .6 degrees in longitude and .4 degrees in latitude in around hour and a half. The surface circulation is still poorly defined given the rapid motion, and is now out in front of the CDO again. 

[Superstorm93]

I don't know if that's a remnant circulation or what, but Chantal is definitely not organized at the surface. 

 

 

 

[Amped]

I don't know if that's a remnant circulation or what, but Chantal is definitely not organized at the surface. 

 

googleearth 2013-07-08 20-43-13-16.png

I'd say goes and microwave did a pretty good job fooling us if thats the case.

 

 

Fast forward speed may make it harder to get west winds on the south side.

[Superstorm93]

NHC track may get "bendy" soon and into Florida...

 

Intensity guidance has kicked up a tad after this makes landfall on Hispaniola and has some time in the Bahamas

 

[Wannabehippie]

NHC track may get "bendy" soon and into Florida...

 

Intensity guidance has kicked up a tad after this makes landfall on Hispaniola and has some time in the Bahamas

 

al032013.png

Question is will it survive passing over Hispaniola or will it get torn apart?

[yoda]

NHC says no thanks tonight for westward bendy track into FL -- http://www.nhc.noaa.gov/graphics_at3.shtml?5-daynl?large#contents

TROPICAL STORM CHANTAL DISCUSSION NUMBER   5NWS NATIONAL HURRICANE CENTER MIAMI FL       AL0320131100 PM AST MON JUL 08 2013THE OVERALL CLOUD PATTERN OF CHANTAL HAS IMPROVED SLIGHTLY SINCETHIS AFTERNOON...WITH MORE BANDING FEATURES EVIDENT IN CONVENTIONALSATELLITE IMAGERY.  THE AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFTINVESTIGATING CHANTAL FOUND A SMALL AREA OF LIGHT NORTHWEST ANDWEST WINDS SOUTH OF THE CENTER AND WERE THEREFORE ABLE TO CLOSE OFFA CIRCULATION.  THE AIRCRAFT REPORTED MAXIMUM FLIGHT-LEVEL WINDS OF58 KT AND BIAS-CORRECTED SFMR WINDS OF 40 TO 42 KT.  A BLEND OF THESFMR AND FLIGHT-LEVEL DATA YIELDS AN INITIAL WIND SPEED OF 45 KT.THE AIRCRAFT REPORTED A SURPRISINGLY HIGH CENTRAL PRESSURE OF 1010MB.CHANTAL CONTINUES TO RACE RAPIDLY WEST-NORTHWESTWARD AT 23 KT. THESTORM IS FORECAST TO CONTINUE ON THIS GENERAL HEADING AND FORWARDSPEED DURING THE NEXT 24 HOURS OR SO...WITH SOME DECELERATEEXPECTED AS IT APPROACHES HISPANIOLA IN 36 TO 48 HOURS.  AFTER THATTIME...A NORTHWESTWARD TURN AND A FURTHER REDUCTION IN FORWARDSPEED IS FORECAST AS A BREAK IN THE RIDGE DEVLOPS OVER THE WESTERNATLANTIC.  AT DAYS 4 AND 5...CHANTAL IS EXPECTED TO MOVE SLOWLYNORTH-NORTHWESTWARD OVER THE BAHAMAS AND WESTERN ATLANTICBETWEEN THE ATLANTIC RIDGE AND A DEVELOPING CUT-OFF LOW OVERTHE SOUTHEASTERN UNITED STATES. THE TRACK GUIDANCE IS IN GOODAGREEMENT DURING THE FIRST 48 HOURS OR SO OF THE FORECASTPERIOD...BUT DIVERGES SOMEWHAT THEREAFTER.  THE LATEST GFS HASSHIFTED NORTHWARD AND IS NOW ALONG THE EASTERN EDGE OF THE GUIDANCEENVELOPE.  THE OFFICIAL FORECAST HAS BEEN NUDGED NORTHWARD ANDEASTWARD TO BE CLOSER TO THE MULTI-MODEL CONSENSUS...BUT IT LIESSOUTH AND WEST OF THE LASTEST GFS AND ECMWF SOLUTIONS.FAVORABLE ENVIRONMENTAL CONDITIONS SHOULD ALLOW FOR GRADUALSTRENGTHENING BEFORE THE SYSTEM REACHES HISPANIOLA.  THE INTENSITYGUIDANCE IS IN GOOD AGREEMENT DURING THE FIRST 36 HOURS...AND THEUPDATED INTENSITY FORECAST IS VERY SIMILAR TO THE PREVIOUS NHCADVISORY.  AFTER CHANTAL INTERACTS WITH HISPANIOLA...THE INTENSITYFORECAST BECOMES QUITE UNCERTAIN.  THE CYCLONE SHOULD WEAKEN WHILE IT INTERACTS WITH LAND AND THE UPPER-LEVEL ENVIRONMENT BECOMES MUCHLESS FAVORABLE.  ALTHOUGH NOT EXPLICITLY SHOWN IN THE FORECAST...CHANTAL COULD WEAKEN BELOW TROPICAL STORM FORCE OR PERHAPS EVENDISSIPATE IN THE 3 TO 4 DAY TIME PERIOD.  NEAR THE END OF THEFORECAST PERIOD...THE UPPER-LEVEL WINDS ARE FORECAST TO BECOMECONDUCIVE FOR RESTRENGTHENING IF THE CYCLONE SURVIVES.  THE OFFICIALFORECAST ASSUMES THAT CHANTAL WILL REMAIN A TROPICAL CYCLONE ANDRE-INTENSIFY UNDER FAVORABLE CONDITIONS AROUND DAY 5.FORECAST POSITIONS AND MAX WINDSINIT  09/0300Z 12.4N  56.1W   45 KT  50 MPH 12H  09/1200Z 13.7N  59.4W   50 KT  60 MPH 24H  10/0000Z 15.3N  63.9W   55 KT  65 MPH 36H  10/1200Z 17.1N  67.9W   60 KT  70 MPH 48H  11/0000Z 19.0N  71.2W   50 KT  60 MPH 72H  12/0000Z 22.5N  75.0W   35 KT  40 MPH 96H  13/0000Z 25.5N  76.5W   35 KT  40 MPH120H  14/0000Z 27.5N  77.5W   45 KT  50 MPH$$FORECASTER BROWN

[icebreaker5221]

Question is will it survive passing over Hispaniola or will it get torn apart?

 

 

I think the current forecast, which would call for a fast forward speed when crossing Hispanola followed by a slowing-down thereafter, is about the best combination we can ask for right now if we want to minimize destruction of the core and allow some time to re-intensify. 

 

Unfortunately, shear is also forecast to be at a maximum as the TC interacts with land (60-72 h), so the damage dealt will likely be swift and harsh.