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HURRICANE FRANKLIN
08-06-2017, 09:19 PM (This post was last modified: 08-06-2017 09:31 PM by Her-icane.)
Post: #11
RE: POTENTIAL TROPICAL CYCLONE SEVEN
Henson for JM


Quote: [Image: ptc7-track-21Z-8.6.17-835px.jpeg]
Tropical Storm Warnings Issued for PTC 7 in Northwest Caribbean
Bob Henson · August 6, 2017, 21:15



Above: Projected track of PTC 7 as of 5:00 pm EDT Sunday, August 6, 2017. Image credit: NOAA/NHC.
Tropical storm warning flags are flying for the Yucatan Peninsula, with a tropical storm watch for the Belize coast, as Potential Tropical Cyclone 7 could become a named storm before it sloshes ashore late Monday. Models agree the system will likely strengthen more dramatically in the Bay of Campeche before an expected second landfall later this week in northeast Mexico.


The NOAA/NWS National Hurricane Center (NHC) upgraded the wave known as Invest 90L to PTC 7 at 5:00 pm EDT Sunday. The new “potential tropical cyclone” designation, which was introduced this year, tracks systems that are not yet tropical storms but that could affect land as tropical storms within 48 hours.


ASCAT scatterometer data at midday Sunday showed that easterly winds of around 30-35 mph extended across a broad zone north of PTC 7. NHC placed the center of this broad low-level circulation about 90 miles east of the northeast tip of Honduras as of 5:00 pm EDT Sunday, moving west-northwest at about 15 mph. The system remained quite asymmetric, with westerly winds weak to nonexistent on its south side. Satellite imagery showed widespread but still poorly organized showers and thunderstorms (convection), with little spin evident. Westerly upper-level winds feeding into a large upper low north of Puerto Rico have imparted strong wind shear (15-25 knots) to the eastern part of PTC 7, with additional shear being produced by a small upper low north of Honduras.



[Image: ir-90L-2015Z-8.6.17.jpg]
Figure 1. Infrared GOES-16 image of PTC 7 as of 2015Z (4:15 pm EDT) Sunday, August 6, 2017, when the system was still designated as Invest 90L. Image credit: NASA/MSFC Earth Science Branch.


Outlook for PTC 7: Two landfalls are likely

Despite PTC 7’s less-than-textbook appearance on Sunday, there are strong signals that the wave will become a tropical storm before it moves west-northwest into the coast of Belize or Mexico’s Yucatan Peninsula late Monday. The wave is heading into a part of the far northwest Caribbean with unusually deep warm water. Sea surface temperatures, or SSTs, are close to 29°C (84°F), more than 1°C above average. Moderate wind shear of 10-15 knots is predicted to slacken below 10 knots by Monday, and the atmosphere around PTC 7 will remain very moist, with mid-level relative humidities around 70%. In its 2:00 pm EDT tropical weather outlook, NHC gave PTC 7 an 80% chance of becoming at least a tropical depression by Tuesday afternoon and a 90% chance through Friday.


The 12Z Sunday run of the HWRF model, our best short-term intensity guidance, shows PTC 7 becoming a strong tropical storm before a landfall in the Quintana Roo district of Mexico on Monday evening. The 12Z runs of the GFS, European, and UKMET models agree on this general track, though without as much intensification. Given PTC 7’s current lack of organization, I would peg its most likely strength at landfall as a weak tropical storm. Heavy rains across the region should be the main threat.


The second chapter of PTC 7’s saga will unfold after it crosses the Yucatan Peninsula. The low-lying, water-surrounded terrain of the peninsula should dent PTC 7’s strength only slightly, especially since the system may still be loosely organized at that point. Global models have come into stronger agreement on a track that would keep PTC 7 moving west-northwest through the Bay of Campeche from Tuesday to Thursday, when it will likely reach the northeast coast of Mexico. The Bay of Campeche is a notoriously favorable area for tropical development, with very warm waters and a concave topography that helps focus storm spin. Models suggest that 99L will be angling leftward as it moves through the bay, which would impart further cyclonic spin and could also hasten intensification.


The official NHC outlook from 5 pm EDT Sunday brings PTC 7 into the coast of northeast Mexico as a strong tropical storm. If PTC 7 enters the bay with a low-level circulation, I would give better than 50-50 odds that it will reach northeast Mexico as a hurricane. The 12Z HWRF suggests that rapid strengthening is possible from Wednesday until a Thursday landfall as a strong Category 2 storm, and the Rapid Intensification index in the 18Z SHIPS model gives a 62% chance that PTC 7 will be a 95-knot hurricane (top-end Category 2) by late Wednesday. Although our three top global models show less strengthening, the HWRF and SHIPS scenario is a real possibility.



[Image: vis-99L-1945Z-8.6.17-637px.jpg]
Figure 2. Visible satellite image of Invest 99L as of 1945Z (2:45 pm EDT) Sunday, August 7, 2016. Image credit: NOAA/NESDIS.





Little change with 99L in the central Atlantic

The wait-and-see game continues with Invest 99L, a large tropical wave rolling through the central Atlantic midway between Africa and the Lesser Antilles. 99L has shown little inclination to organize over the last several days, and it remains quite elongated as it pushes west-northwest at about 15 mph.


The strong zone of high pressure in the central Atlantic pushing 99L westward is also leading to subsidence and drying, and this dry air will be a thorn in 99L’s side. The wave will be encountering a large extension of the Saharan Air Layer (see Figure 3 below) over the next couple of days. The 18Z SHIPS model shows mid-level relative humidities around 99L will drop from around 60% to around 55% from Monday onward. Moderate wind shear of 10-15 knots, increasing to 15-20 knots by Tuesday, may also impede PTC 7’s growth.


In its 2:00 pm EDT tropical weather outlook, NHC gave PTC 7 an 20% chance of becoming at least a tropical depression by Tuesday afternoon and a 50% chance through Friday.



[Image: sal-18Z-8.6.17.png]
Figure 3. A patch of the Saharan Air Layer (SAL) lies ahead of 99L west-northwest track over the next several days. Image credit: UW-CIMMS/NOAA Hurricane Research Division.


The leading global models have come into closer agreement on 99’s fate, which seems most likely to be unimpressive but with a small chance of U.S. impacts more than a week from now. Of the ensemble runs from 0Z Sunday, less than 20% of the 50 European model members led a tropical storm near or just north of the Leeward Islands by Wednesday. A small fraction (less than 10%) continued 99L on a northwestward track that had the system approaching the U.S. East Coast as a tropical storm or hurricane around 7 to 9 days from now. As in past days, the GFS model was more bullish on 99L, with about two-thirds of its 20 ensemble members producing a tropical storm and about 25% carrying the system toward Florida and/or the Gulf of Mexico as a tropical storm or hurricane by next weekend. The operational UKMET model from 0Z Sunday suggested the potential for an East Coast system, while the operational GFS and ECMWF runs did not develop 99L significantly through 7 days.


There is plenty of time to see if 99L manages to organize as it approaches the Leeward Islands. Based on the trend of global models, 99L or its remnants will ultimately head toward the United States. We may need to keep at least one eye on 99L even if it approaches the U.S. as a weak system, since rapid spin-ups are possible in the Bahamas and Gulf of Mexico this time of year.

.

000
NOUS42 KNHC 061930
REPRPD
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
0330 PM EDT SUN 06 AUGUST 2017
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 07/1100Z TO 08/1100Z AUGUST 2017
TCPOD NUMBER.....17-067 CORRECTION

I. ATLANTIC REQUIREMENTS
1. SUSPECT AREA (CARIBBEAN SEA)
FLIGHT ONE -- TEAL 72
A. 07/1730Z
B. AFXXX 01DDA INVEST
C. 07/1400Z
D. 18.5N 86.5W
E. 07/1700Z TO 07/2330Z
F. SFC TO 10,000 FT

2. OUTLOOK FOR SUCCEEDING DAY:
A. BEGIN POSSIBLE 6-HRLY FIXES AT 08/1730Z
NEAR 20.5N 91.0W.
B. POSSIBLE NOAA42 TAIL DOPPLER RADAR MISSIONS
DEPARTING KLAL AT 08/1800Z AND 09/0600Z.

3. REMARKS:
A. INVEST MISSION SCHEDULED FOR 06/1800Z CANCELLED
BY NHC AT 06/1005Z.
B. MISSION SCHEDULED FOR 07/1130Z, 1730Z
REQUIREMENTS WILL DELAY SIX HOURS. SEE REVISED
FLIGHT INFORMATION ABOVE.
C. CORRECTED LOCATION IN ITEM 2A ABOVE.



II. PACIFIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. SUCCEEDING DAY OUTLOOK.....NEGATIVE.

$$
WJM
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08-07-2017, 06:43 AM
Post: #12
RE: TROPICAL STORM FRANKLIN
Tropical Storm Franklin Discussion Number 3
NWS National Hurricane Center Miami FL AL072017
500 AM EDT Mon Aug 07 2017

Deep convection associated with Franklin has been steadily
increasing in both coverage and vertical depth since the previous
advisory. Wind data from a late-arriving 0231Z ASCAT-A pass suggest
that Franklin might not have had a closed surface circulation at
that time. However, the new GOES-16 nighttime microphysics imagery
clearly shows low clouds moving from west to east on the south side
of the alleged center, which is suggestive of a closed low-level
circulation. The intensity has been nudged upward to 40 kt based on
sustained winds of 39 kt measured at 4-meters elevation from NOAA
buoy 42057 located about 110 nmi east of the center.

The initial motion estimate is 300/12 kt. The latest NHC model
guidance remains in excellent agreement that Franklin will continue
to move west-northwestward along the south side of a deep-layer
ridge during the next 48 hours or so, making landfall along the
east coast of the Yucatan peninsula in 18-24 hours. After the
cyclone crosses over Yucatan and moves into the Bay of Campeche by
Wednesday, a more westward motion is expected thereafter as the
ridge currently situated over northern Mexico and the southwestern
U.S. builds southward. The track model guidance is tightly clustered
around the previous forecast track, so the new forecast track is
just an extension of the previous one and lies down the middle of
the guidance envelope.

Upper-level outflow continues to expand in the western semicircle,
and a pronounced poleward outflow channel has developed in the
northern semicircle, which is being aided by a large upper-level low
located north of Puerto Rico. Although UW-CIMSS wind analyses
indicate that modest westerly mid-level shear is still affecting the
cyclone, that hindrance is forecast to abate in another 6 h or so.
Both the GFS and ECMWF models are forecasting the deep-layer and
mid-level shear to decrease to near zero in the 12-24 h period,
suggesting that Franklin could undergo a period of rapid
intensification right up until landfall occurs. Unfortunately, the
official intensity forecast does not directly reflect that possible
intensification trend due to the 24-h position being inland over
Yucatan with weakening occuring at that time due to land
interaction. Franklin is likely to reach a peak intensity of about
60 kt or so prior to landfall, and for that reason the government of
Mexico has issued a Hurricane Watch. The cyclone will weaken some as
it moves over the Yucatan, but re-strengthening is expected after
Franklin emerges over the very warm waters of the Bay of Campeche in
the 48-72 h period. The NHC intensity forecast remains close to the
higher SHIPS guidance at 24 hours, and is near the IVCN and HCCA
consensus models after that time.

FORECAST POSITIONS AND MAX WINDS

INIT 07/0900Z 17.1N 84.2W 40 KT 45 MPH
12H 07/1800Z 18.0N 85.8W 50 KT 60 MPH
24H 08/0600Z 19.0N 88.0W 55 KT 65 MPH...INLAND
36H 08/1800Z 19.9N 90.2W 40 KT 45 MPH...INLAND
48H 09/0600Z 20.4N 92.3W 45 KT 50 MPH...OVER WATER
72H 10/0600Z 21.0N 96.4W 55 KT 65 MPH
96H 11/0600Z 21.1N 100.5W 25 KT 30 MPH...INLAND
120H 12/0600Z...DISSIPATED

$$
Forecaster Stewart
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08-07-2017, 09:06 AM (This post was last modified: 08-07-2017 09:12 AM by Her-icane.)
Post: #13
RE: TROPICAL STORM FRANKLIN
Henson for JM


Quote: [Image: franklin-ir-0327Z-8.6.17-835px.jpg]

Tropical Storm Franklin Develops in NW Caribbean

Bob Henson · August 7, 2017, 04:07



Above: Satellite image of Tropical Storm Franklin late Sunday night, August 6, 2017.


The sixth tropical storm of the 2017 Atlantic season was gaining strength late Sunday as it headed toward a landfall on the Yucatan Peninsula late Monday. Tropical storm warnings were in effect for most of the Yucatan Peninsula coastline of Mexico, with a tropical storm watch southward on either side of the peninsula, including the northern Belize coast.


Franklin was designated a tropical storm by the NOAA/NWS National Hurricane Center at 11 pm EDT Sunday, when the storm was located only about 100 miles north of the northeast tip of Honduras. A NOAA buoy northeast of the center reported sustained winds of minimal tropical storm strength, 35 knots (40 mph). Showers and thunderstorms (convection) were blossoming around Franklin’s newly consolidated center late Sunday, and an increasing amount of spin was evident in satellite loops. The center of Franklin is far enough north of the Honduras coast to minimize land interactions as the storm continues on its west-northwest course, moving at about 13 mph. Computer forecast models are in strong agreement on Franklin’s path, which should curve gently to the left as the storm moves across the Yucatan peninsula and into the Bay of Campeche.



[Image: franklin-tracking-3Z-8.7.16.jpeg]
Figure 1. WU depiction of NHC tracking map for Tropical Storm Franklin as of 11 pm EDT Sunday, August 4, 2017. There is potential for Franklin to reach hurricane strength between the 12 AM Thursday and 12 AM Friday positions, as discussed below.


Intensity outlook for Franklin


The intensity outlook for Franklin has changed little from our detailed report on Sunday afternoon. Franklin will likely reach the Yucatan as a strong tropical storm. An intensification to Category 1 hurricane strength just prior to landfall cannot be ruled out, given the very warm waters east of the Yucutan, the high oceanic heat content there, and the expected lessening of wind shear around Franklin on Monday. A Hurricane Hunter flight into Franklin has been scheduled for midday Monday. On its expected track, the highest winds from Franklin would most likely affect the sparsely populated southern part of Mexico’s Quintana Roo province, but gales may extend well northward along the coast. Torrential rains of 3” - 6” or more can be expected across the region.


Franklin’s trek across the flat terrain of the Yucatan should have only a minor dampening effect, and the storm is liable to intensify further when it reaches the warm waters of the Bay of Campeche. The official NHC forecast at 11 pm EDT Sunday called for Franklin to arrive at the northeast coast of Mexico on Thursday morning. Our best model for intensity forecasts, the HWRF, has been consistent in projecting that Franklin could be a Category 2 hurricane by the time of this second landfall, and the 0Z Sunday SHIPS model output indicates a 58% chance that Franklin will become a 100-knot hurricane (Category 3) while in the Bay of Campeche. Because the official NHC forecast provides intensities at 72- and 96-hour intervals, it does not include a predicted strength for the 12 hours on either side of Franklin’s second landfall (which is expected around the 84-hour point). Overall, it appears that odds favor at least a Category 1 landfall in northeast Mexico on Thursday.

[Image: vis0.gif]
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08-07-2017, 02:07 PM (This post was last modified: 08-07-2017 02:50 PM by Her-icane.)
Post: #14
RE: TROPICAL STORM FRANKLIN
Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 7th day of the month at 17:49Z
Agency: United States Air Force
Aircraft: Lockheed WC-130J Hercules with reg. number AF97-5304
Storm Number & Year: 07 in 2017
Storm Name: Franklin (flight in the North Atlantic basin)
Mission Number: 1
Observation Number: 07
A. Time of Center Fix: 7th day of the month at 17:20:10Z
B. Center Fix Coordinates: 17°59'N 85°12'W (17.9833N 85.2W)
B. Center Fix Location: 200 statute miles (322 km) to the E (80°) from Belize City, Belize.
C. Minimum Height at Standard Level: 1,405m (4,610ft) at 850mb
D. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 48kts (~ 55.2mph)
E. Location of the Estimated Maximum Surface Wind Inbound: 58 nautical miles (67 statute miles) to the NNE (25°) of center fix
F. Maximum Flight Level Wind Inbound: From 121° at 46kts (From the ESE at ~ 52.9mph)
G. Location of Maximum Flight Level Wind Inbound: 21 nautical miles (24 statute miles) to the NNE (24°) of center fix
H. Minimum Sea Level Pressure: 999mb (29.50 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 16°C (61°F) at a pressure alt. of 1,530m (5,020ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 19°C (66°F) at a pressure alt. of 1,521m (4,990ft)
K. Dewpoint Temp & Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Open in the northwest, NW
M. Eye Shape & Diameter: Circular with a diameter of 16 nautical miles (18 statute miles)
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: 3 nautical miles

Remarks Section:
Maximum Flight Level Wind: 46kts (~ 52.9mph) which was observed 21 nautical miles (24 statute miles) to the NNE (24°) from the flight level center at 17:13:30Z
Dropsonde Surface Wind at Center: From 220° at 8kts (From the SW at 9mph)


=========================================================


[/font][font=Arial]




Henson for JM


Quote: [Image: franklin-ir-1615Z-8.7.17-835px.jpg]

Tropical Storm Franklin Aims for Yucatan
Bob Henson · August 7, 2017, 17:56



Above: GOES-16 infrared satellite image of Hurricane Franklin as of 1615Z (12:15 pm EDT) Monday, August 7, 2017. GOES-16 data are preliminary and non-operational. Image credit: NASA/MSFC Earth Science Branch.
Steadily gathering strength in the northwest Caribbean, Tropical Storm Franklin is on course to strike the eastern coast of the Yucatan Peninsula on Monday night. Franklin could undergo a brief period of rapid intensification that makes it a hurricane just before landfall. At 11 am EDT Monday, a hurricane watch and a tropical storm warning were in effect for the Mexican coast from Chetumal to Punta Allen. Additional parts of the Yucatan coast of Mexico and Belize were under tropical storm watches or warnings.


After days as a loosely organized tropical wave rolling through the Caribbean, Franklin began consolidating on Sunday and became a tropical storm on Sunday night. At 2 pm EDT Monday, the NOAA/NWS National Hurricane Center was locating the center Franklin at about 185 miles east of Belize City, with top sustained winds up to 60 mph. A large shield of intense thunderstorms covered the area near and to the north and east of Franklin’s center, with increasing upper-level outflow evident on the fringes of this shield. A Hurricane Hunter flight found winds of 48 knots at flight level well northeast of Franklin’s center at 12:44 pm EDT Monday, with the center located just south of a small dry slot evident in satellite imagery.



[Image: franklin-viz-16Z-8.7.17.jpeg]
Figure 1. GOES-16 visible-wavelength satellite image of Hurricane Franklin as of 1600Z (noon EDT) Monday, August 7, 2017. Satellite loops show that the feature resembling an eye is most likely a dry slot wrapped just north of the main center of circulation, rather than a true eye. Image credit: NASA/MSFC Earth Science Branch.


Outlook for Franklin

Conditions are very supportive of further growth in the few hours before Franklin makes landfall on Monday night, especially now that the storm is organized enough to take advantage of the favorable set-up. Wind shear will drop below 10 knots by Monday afternoon, according to 12Z Monday output from the SHIPS statistical model. Sea surface temperatures of 29-30°C (84-86°F) are about 1°C above average for this time of year, and Franklin is passing across an area of deep oceanic heat content, which lowers the odds that strong winds will bring cooler water to the surface.



[Image: oceanic-heat-8.6.17.jpg]
Figure 2. Tropical cyclone heat potential (TCHP) across the Caribbean Sea as of Sunday, August 6, 2017, in kilojoules per square centimeter. TCHP integrates the amount of heat through the depth of the upper ocean as measured by temperatures at each level. The red and white zone across the northwest Caribbean is associated with hurricane-supportive water temperatures of at least 26°C (79°F) that extend more than 125 meters (410 feet) deep. Image credit: NOAA/AOML.
Although it is not shown in the official NHC forecast (Figure 3 below), it is quite possible that Franklin will become a Category 1 hurricane just before landfall, between the forecast points at 7 pm EDT Monday and 7 am EDT Tuesday. If so, it will be the first Atlantic hurricane of 2017. In records going back to 1851, only four other years have seen six Atlantic tropical storms or hurricanes by August 6, according to Phil Klotzbach (Colorado State University). Those years are 1936, 1959, 2005, and 2012.


Torrential rain should be the main threat from Franklin, although gale-force winds may extend more than 100 miles up the coast from where Franklin makes landfall on the Yucatan Peninsula.



[Image: wu-tracking-franklin-15Z-8.7.17-640px.jpg]
Figure 3. WU depiction of the official NHC forecast for Franklin as of 11:00 am EDT Monday, August 7, 2017.
Computer models are in very close agreement on Franklin’s track, which will make a gentle leftward arc across the Yucatan Peninsula and the Bay of Campeche. Franklin will exit the peninsula in a weakened state, though still likely a tropical storm. Although it is not shown on the tracking map—because it would occur between forecast points—Franklin may have a second brief chance at rapid intensification to hurricane strength just before it makes landfall on the northeast coast of Mexico well south of Tampico. The concave topography of the Bay of Campeche helps impart spin to tropical cyclones, and water temperatures will again be very warm, although the oceanic heat content is less than in the northwest Caribbean.


The last several runs of the HWRF model—our best short-term guidance for tropical cyclone intensity—has been consistent in bringing Franklin to northeast Mexico late Wednesday night as a Category 1 hurricane.



A good analog for Franklin is 2012’s Hurricane Ernesto, which became a tropical storm several days before approaching the Yucatan on a very similar track to Franklin’s—and on the same day of the year to boot (see embedded tweet below from Brian McNoldy). Ernesto quickly strengthened to Category 2 intensity just before landfall on the coast of Mahahual, Mexico. Ernesto failed to regain hurricane status after passing over the Bay of Campeche, but Franklin’s track is expect to be far enough north of Ernesto’s to give it more time over the bay’s warm waters without direct interference from land.

[Image: ir-99L-1645Z-8.7.17-720px.jpg]
Figure 4. Enhanced infrared image of Invest 99L as of 1645Z (12:45 pm EDT) Monday, August 7, 2017. Image credit: NOAA/NESDIS.


99L: No worries for the time being

The long-struggling tropical wave in the central Atlantic known as Invest 99L continues to persevere, but its long-term future remains highly uncertain. Dry air from the Saharan Air Layer, and moderate to strong wind shear of 10-20 knots, have taken a toll on the disorganized showers and thunderstorms (convection) around 99L’s weak, elongated center, which is located midway between the Cape Verde islands and the Lesser Antilles. There were some hints of a more centralized convective pattern developing in satellite imagery on Monday (see Figure 4). We'll see if this apparent trend continues with the approach of nighttime, when convection over the tropics typically reaches a diurnal peak.


Wind shear and dry air will continue to plague the resilient 99L for at least the next several days. The wave is moving toward warmer sea surface temperatures, and it could hang together long enough for a renewed chance at intensification once it reaches the area near or north of the Lesser Antilles. Overall, though, models have pulled back on the idea of long-term strengthening of 99L. Between 10% and 20% of the European ensemble members from Sunday evening indicate that 99L could yet become a tropical storm late this week or even early next week, potentially heading toward the U.S. East Coast more than a week from now. Only 1 of 20 GFS ensemble members bring 99L to tropical storm strength, and all of those members dissipate the system before it could get as far west as Puerto Rico. None of the three most reliable long-term models—the GFS, Euro, and UKMET—developed 99L in their operational runs from Sunday night.


In its 2:00 pm EDT Monday tropical weather outlook, NHC gave 99L a near-zero chance of becoming at least a tropical depression by Wednesday and a 20% chance through Saturday.


.

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 7th day of the month at 19:41Z
Agency: United States Air Force
Aircraft: Lockheed WC-130J Hercules with reg. number AF97-5304
Storm Number & Year: 07 in 2017
Storm Name: Franklin (flight in the North Atlantic basin)
Mission Number: 1
Observation Number: 14
A. Time of Center Fix: 7th day of the month at 19:01:40Z
B. Center Fix Coordinates: 18°18'N 85°29'W (18.3N 85.4833W)
B. Center Fix Location: 185 statute miles (298 km) to the E (94°) from Chetumal, Quintana Roo, Mexico.
C. Minimum Height at Standard Level: 1,427m (4,682ft) at 850mb
D. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 48kts (~ 55.2mph)
E. Location of the Estimated Maximum Surface Wind Inbound: 17 nautical miles (20 statute miles) to the SSE (159°) of center fix
F. Maximum Flight Level Wind Inbound: From 209° at 39kts (From the SSW at ~ 44.9mph)
G. Location of Maximum Flight Level Wind Inbound: 27 nautical miles (31 statute miles) to the SSE (150°) of center fix
H. Minimum Sea Level Pressure: 998mb (29.47 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 16°C (61°F) at a pressure alt. of 1,527m (5,010ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 19°C (66°F) at a pressure alt. of 1,507m (4,944ft)
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: 3 nautical miles

Remarks Section:
Maximum Flight Level Wind: 46kts (~ 52.9mph) which was observed 23 nautical miles (26 statute miles) to the E (87°) from the flight level center at 17:13:30Z
Maximum Flight Level Wind Outbound: 42kts (~ 48.3mph) which was observed 16 nautical miles (18 statute miles) to the NW (324°) from the flight level center at 19:06:30Z
Dropsonde Surface Wind at Center: From 255° at 7kts (From the WSW at 8mph)

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08-07-2017, 05:03 PM
Post: #15
RE: TROPICAL STORM FRANKLIN
Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 7th day of the month at 21:13Z
Agency: United States Air Force
Aircraft: Lockheed WC-130J Hercules with reg. number AF97-5304
Storm Number & Year: 07 in 2017
Storm Name: Franklin (flight in the North Atlantic basin)
Mission Number: 1
Observation Number: 20
A. Time of Center Fix: 7th day of the month at 20:45:00Z
B. Center Fix Coordinates: 18°35'N 85°52'W (18.5833N 85.8667W)
B. Center Fix Location: 159 statute miles (257 km) to the E (88°) from Chetumal, Quintana Roo, Mexico.
C. Minimum Height at Standard Level: 1,397m (4,583ft) at 850mb
D. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 50kts (~ 57.5mph)
E. Location of the Estimated Maximum Surface Wind Inbound: 32 nautical miles (37 statute miles) to the SW (222°) of center fix
F. Maximum Flight Level Wind Inbound: From 318° at 31kts (From the NW at ~ 35.7mph)
G. Location of Maximum Flight Level Wind Inbound: 33 nautical miles (38 statute miles) to the SW (222°) of center fix
H. Minimum Sea Level Pressure: 996mb (29.42 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 15°C (59°F) at a pressure alt. of 1,526m (5,007ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 19°C (66°F) at a pressure alt. of 1,521m (4,990ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 15°C (59°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: 850mb
O. Navigational Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 5 nautical miles

Remarks Section:
Maximum Outbound and Flight Level Wind: 59kts (~ 67.9mph) which was observed 20 nautical miles (23 statute miles) to the NE (43°) from the flight level center at 20:51:30Z
Dropsonde Surface Wind at Center: From 70° at 3kts (From the ENE at 3mph)

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08-07-2017, 07:29 PM (This post was last modified: 08-07-2017 07:34 PM by Her-icane.)
Post: #16
RE: TROPICAL STORM FRANKLIN
[Image: 234310_5day_cone_no_line_and_wind.png]

[Image of probabilities of 34-kt winds]

000
WTNT42 KNHC 072033
TCDAT2

Tropical Storm Franklin Discussion Number 5
NWS National Hurricane Center Miami FL AL072017
400 PM CDT Mon Aug 07 2017

Visible satellite imagery continues to show a fairly well-organized
tropical cyclone, although infrared images indicate some warming of
the convective cloud tops. Observations from an Air Force Hurricane
Hunter aircraft show that the storm has a fairly broad inner core,
which is consistent with the ragged eye-like feature noted on the
visible imagery. The current intensity is kept at 50 kt based on a
blend of SFMR and flight-level observations from the aircraft along
with sampling considerations. Franklin has a well-defined,
symmetric upper-level outflow pattern, and some strengthening is
still expected prior to landfall. Although the cyclone could be near
hurricane strength at landfall on the east coast of the Yucatan
peninsula, the broad inner core of the system would argue against
rapid intensification during the next 12 hours
. Weakening will occur
due to the passage over the Yucatan peninsula, and restrengthening
over the very warm waters of the Bay of Campeche is forecast.
Although northerly shear could inhibit strengthening somewhat,
Franklin is predicted to become a hurricane before making
landfall in mainland Mexico
. The official intensity forecast is
similar to the latest HFIP Corrected Consensus forecast.

Based on center fixes from the aircraft along with geostationary
and microwave imagery, the initial motion is northwestward or
310/11 kt. The track forecast reasoning remains basically
unchanged. A mid-level high pressure area near the northwestern
Gulf of Mexico coast should force Franklin to take a
west-northwestward to westward course for the next several days
.


FORECAST POSITIONS AND MAX WINDS

INIT 07/2100Z 18.6N 85.9W 50 KT 60 MPH
12H 08/0600Z 19.1N 87.6W 60 KT 70 MPH...INLAND
24H 08/1800Z 19.9N 89.9W 40 KT 45 MPH...INLAND
36H 09/0600Z 20.3N 91.9W 50 KT 60 MPH...OVER WATER
48H 09/1800Z 20.5N 94.0W 65 KT 75 MPH...OVER WATER
72H 10/1800Z 20.5N 98.5W 55 KT 65 MPH...INLAND
96H 11/1800Z...DISSIPATED

$$
Forecaster Pasch
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08-07-2017, 09:55 PM
Post: #17
RE: TROPICAL STORM FRANKLIN
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08-08-2017, 11:56 AM
Post: #18
RE: TROPICAL STORM FRANKLIN
Henson for JM

Quote: [Image: franklin-wv-0800Z-8.8.17-835px.jpg] Franklin Pushes Inland over Yucatan, Headed for Bay of Campeche
Bob Henson · August 8, 2017, 08:37



Above: GOES-16 water-vapor satellite image of Hurricane Franklin as of 0800Z (4:00 am EDT) Tuesday, August 8, 2017. GOES-16 imagery is preliminary and non-operational. Image credit: NASA/MSFC Earth Science Branch.

Tropical Storm Franklin was rolling across the Yucatan Peninsula early Tuesday after crashing ashore near Pulticub, Mexico, at around 10:45 pm EDT Monday. Franklin made landfall with top sustained winds of 60 mph. As of 5:00 am EDT Tuesday, Franklin was located just inland, about 55 miles north-northwest of Chetumal, over a sparsely populated section of Mexico’s Quintana Roo state. A NOAA buoy reported gusts to 47 mph more than 200 miles east-northeast of Franklin's center early Tuesday morning. Well to the north of Franklin, Cozumel reported 3.80” of rain on Monday, but top winds at Cozumel had reached only 23 mph as of 4 am EDT Tuesday. Winds and rainfall were even lighter at Chetumal, on Franklin’s much-weaker south side.


Franklin took advantage of highly favorable conditions east of the Yucatan on Monday to become a well-structured tropical storm, with excellent outflow evident on satellite imagery. However, the showers and thunderstorms (convection) surrounding Franklin’s center were not as intense as they could have been, and the storm’s center was large and somewhat diffuse. These factors may be what kept Franklin from quickly become a hurricane before landfall—good news for residents and visitors along the Yucatan coast!


As of early Tuesday, Franklin’s shield of convection had become more fragmented and notably less impressive as the storm worked its way inland. However, the core of the storm had become more organized, with a closed eye evident on radar. This new organization may work in Franklin's favor once the storm moves off the west side of the Yucatan peninsula. Tropical storm warnings remained in effect Tuesday morning on both sides of the peninsula.


[Image: belize-radar-0501Z-8.8.17.jpeg]Figure 1. Radar display from the Philip Goldson Airport at Belize City, Belize, at 0501Z (1:00 am EDT) Tuesday, August 8, 2017, a little more than two hours after Franklin made landfall north of Belize. Image credit: National Meteorological Service of Belize.
[Image: franklin-goes-viz-1600Z-8.7.17.png][b][b]Figure 2. [/b][/b]GOES-E visible-light satellite image of Tropical Storm Franklin at 1600Z (noon EDT) Monday, August 7, 2017, as Franklin was intensifying north of Honduras. Image credit: NASA-NOAA GOES Project.
[Image: wu-tracking-franklin-6Z-8.8.17.jpg]Figure 3. WU depiction of NHC forecast for Tropical Storm Franklin issued at 5 am EDT Tuesday, August 8, 2017.


Outlook for Franklin


Franklin's top winds are expected to gradually weaken over land before the center moves off the west coast of the Yucatan peninsula on Tuesday afternoon. At that point, Franklin will be a minimal tropical storm, perhaps even a tropical depression. The storm is predicted to get a second lease on life over the warm waters and supportive geography of the Bay of Campeche. In its forecast from 5:00 am EDT Tuesday, the NOAA/NHC National Hurricane Center predicted that Franklin would approach hurricane strength before making its second landfall early Thursday, expected to occur on the northeast Mexican coast north of Tampico. Models are in close agreement on this west-northwest track, though with some differences on how far north or south landfall will occur.


Given how weak Franklin is expected to be when it enters the bay, it is now unlikely that the storm will be able to rapidly intensify beyond Category 1 strength before it makes landfall, especially with moderate wind shear now expected. The HWRF model, our most reliable for intensity predictions, has pulled back on its projected strength. In its 00Z Tuesday run, HWRF called for Franklin to be near or just above minimal hurricane strength at landfall, and this appears to be a reasonable outlook, not far from the NHC forecast. A hurricane watch was in effect Tuesday morning on the northeast Mexican coast from Sabancuy to Puerto de Veracruz. Torrential rains and a mudslide risk may take shape across parts of central and northeast Mexico after Franklin's second landfall, as the storm's convective shield is likely to expand and consolidate by that point.
.


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08-08-2017, 07:55 PM (This post was last modified: 08-08-2017 07:57 PM by Her-icane.)
Post: #19
RE: TROPICAL STORM FRANKLIN
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08-08-2017, 10:49 PM
Post: #20
RE: TROPICAL STORM FRANKLIN
[Image: DGwYvb8XsAEzgR-.jpg:large]

000
WTNT32 KNHC 090253
TCPAT2

BULLETIN
Tropical Storm Franklin Advisory Number 10
NWS National Hurricane Center Miami FL AL072017
1000 PM CDT Tue Aug 08 2017

...FRANKLIN STRENGTHENING OVER THE BAY OF CAMPECHE...
...HURRICANE WARNING ISSUED FOR PORTIONS OF THE MEXICAN STATE OF
VERACRUZ...


S
UMMARY OF 1000 PM CDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...20.3N 91.3W
ABOUT 250 MI...400 KM NE OF COATZACOALCOS MEXICO
ABOUT 325 MI...525 KM ENE OF VERACRUZ MEXICO
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...996 MB...29.42 INCHES
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