Windspeed

Recon going to get there right when a strong convective burst is going up. Should be at operational altitude in about 30 minutes.

Oh that's really a bad track for post-Laura recovery. Long way to go though.

Oh, hello ECMWF. So kind of you to join us.

The 12z GFS has backed off on stronger shear over the N. GOM. That doesn't mean it won't come back on the next run. That being said, there is a possibility that an intense Delta might not be rapidly weakening due to shear versus just leveling off and slowly weakening upon landfall. The SSTs around 26-26.5°C several hundered miles south of the coast will definitely halt intensification or start a weakening trend, but if Delta is hauling ass northward and at Cat 3 to 4 intensity, there is a chance it could still be a major at landfall if the weakening trend starts off slowly.

11 AM EDT discussion. I do think they're underdoing maximum intensity. After recon data is returned this afternoon, I'd imagine they'll bump up the forecasted intensity to a Category 3 on the 5 PM. We'll just have to wait and see how organized the vortex is per recon. ZCZC MIATCDAT1 ALL TTAA00 KNHC DDHHMM Tropical Storm Delta Discussion Number 4 NWS National Hurricane Center Miami FL AL262020 1100 AM EDT Mon Oct 05 2020 The convective structure of Delta has continued to improve this morning. Earlier microwave data and early-light visible satellite imagery showed that the center of the tropical cyclone re-formed farther south within the area of deep convection. Since that time, banding has continued to increase around the southern and eastern portion of the circulation, and a small CDO-like feature has formed. The intensity has been set at 40 kt, which is a blend of the subjective Dvorak estimate from TAFB and objective satellite intensity estimates from UW/CIMSS. A NOAA Hurricane Hunter aircraft is scheduled to investigate the tropical storm this afternoon, which should provide a better assessment of the cyclone's intensity, structure, and wind field. With the earlier center re-formation, the initial motion estimate is a somewhat uncertain 280/6 kt. Delta is expected to resume a west-northwestward motion later today. A northwestward heading around the southwestern portion of a deep-layer ridge should begin tonight or Tuesday, and that general motion with some increase in forward speed is expected to continue through 60-72 hours. After that time, a broad mid- to upper-level trough is forecast to develop over the south-central United States, which should weaken the western portion of the ridge and cause Delta to turn northward toward the northern Gulf Coast. After day 4, Delta should begin to accelerate north-northeastward or northeastward ahead of the aforementioned trough. The new NHC track forecast has been adjusted to the south and west of the previous advisory during the first couple of days, primarily due to the recent center re-formation and more southward initial position. After that time, the NHC track is not much different than the previous forecast and lies near the center of the tightly clustered dynamical model envelope. Delta is forecast to traverse very warm waters over the northwestern Caribbean Sea and be in a very low vertical wind shear environment during the next couple of days. These conditions should allow for significant strengthening during that time, and the NHC intensity forecast is at or above the various intensity aids. It is somewhat surprising that the intensity aids were generally a little lower this cycle, but the expected low shear and SHIPS rapid intensification index support the higher than climatological rate of intensification. After 72 hours, increasing southwesterly shear and the cooler shelf waters over the northern Gulf are likely to induce some weakening later in the period. The updated NHC intensity forecast calls for a faster rate of intensification over the next 48-60 hours, but is similar to the previous advisory thereafter. Key Messages: 1. Tropical storm conditions are expected in the Cayman Islands beginning late today or tonight, and a Tropical Storm Warning is in effect. 2. Dangerous storm surge and hurricane conditions are expected in portions of western Cuba by Tuesday afternoon, and a Hurricane Warning is in effect. 3. Heavy rainfall will affect portions of Jamaica, the Cayman Islands, and western Cuba during the next few days. This rainfall could lead to significant flash flooding and mudslides. 4. Delta is forecast to approach the northern Gulf Coast late this week as a hurricane. While there is large uncertainty in the track and intensity forecasts at these time ranges, there is an increasing risk of dangerous storm surge, wind, and rainfall hazards along the coast from Louisiana to the western Florida Panhandle. Residents in these areas should monitor the progress of Delta and check for updates to the forecast during the week. FORECAST POSITIONS AND MAX WINDS INIT 05/1500Z 16.4N 78.6W 40 KT 45 MPH 12H 06/0000Z 17.1N 79.6W 50 KT 60 MPH 24H 06/1200Z 18.7N 81.7W 60 KT 70 MPH 36H 07/0000Z 20.8N 84.3W 75 KT 85 MPH 48H 07/1200Z 22.8N 86.8W 85 KT 100 MPH 60H 08/0000Z 24.6N 89.1W 90 KT 105 MPH 72H 08/1200Z 26.0N 90.7W 90 KT 105 MPH 96H 09/1200Z 28.8N 91.1W 85 KT 100 MPH 120H 10/1200Z 33.1N 88.2W 40 KT 45 MPH...INLAND $$ Forecaster Brown NNNN

There is virtually no upper tropospheric influence from Gamma now as it is devoid of convection reaching mid-to-upper levels. Therefore, the more dominate upper ridge axis is likely to take over upper wind flow. Delta should be in a low shear environment as it traverses the NW Caribbean towards the channel. Additionally Delta's own intense convection is squashing what remains of the small PV feature. I think the TC models were overdoing Gamma's influence or there is convective feedback issues with what they are modeling as a TC north of the Yucatan when in reality it is just a low level wind / steering feature now with no influence on mid to upper heights.

Yeah the critical issue with Delta will be how intense and how large it becomes during major hurricane status as it traverses from NW Caribbean to the central GOM to drive up surge. Even if it weakens rapidly into landfall, its forward motion and overall circulation could still mean significant storm surge along the N. GOM coast. Additionally, due to the system being less influenced by Gamma, it may also drive further WNW initially putting Cozumel under threat. Still big questions remaining and the potential for the track to shift west in the forecast.

SHIPs RI is skyrocketing: [emoji102]

Based on organizational trends, I'm going to push all my chips in here and say Delta reaches major hurricane intensity by tomorrow evening and becomes a Category 4 by Wednesday. Too much going for Delta and Gamma's influence is now going to be minimal seeing as that vortex has no real mid-level circulation.

Visible alone reveals that short-term trend well enough. The system is getting stacked and moving into a better environment for intensification.

Based on short-term trends, I think you have to throw those out. The organization of the vortex looks way ahead of any modeling solution including the TC models.

Here's the 8AM EDT upgrade: 000 WTNT31 KNHC 051139 TCPAT1 BULLETIN Tropical Storm Delta Intermediate Advisory Number 3A NWS National Hurricane Center Miami FL AL262020 800 AM EDT Mon Oct 05 2020 ...TROPICAL DEPRESSION STRENGTHENS INTO A TROPICAL STORM... ...ADDITIONAL STRENGTHENING LIKELY OVER THE NEXT FEW DAYS... SUMMARY OF 800 AM EDT...1200 UTC...INFORMATION ---------------------------------------------- LOCATION...16.4N 78.4W ABOUT 130 MI...210 KM S OF NEGRIL JAMAICA ABOUT 270 MI...440 KM SE OF GRAND CAYMAN MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H PRESENT MOVEMENT...WNW OR 290 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Watch is in effect for... * Cuban provinces of Pinar del Rio and Artemisa * Isle of Youth A Tropical Storm Warning is in effect for... * Cayman Islands including Little Cayman and Cayman Brac A Tropical Storm Watch is in effect for... * Cuba province of La Habana A Hurricane Watch means that hurricane conditions are possible within the watch area, generally within 48 hours. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 800 AM EDT (1200 UTC), the center of Tropical Storm Delta was located near latitude 16.4 North, longitude 78.4 West. The storm is moving toward the west-northwest near 9 mph (15 km/h), and this general motion should continue for the next day or so. A faster northwestward motion is expected on Tuesday and Wednesday. On the forecast track, the center of Delta is expected to move away from Jamaica later today, move near or over the Cayman Islands later tonight, and approach the Isle of Youth and western Cuba Tuesday afternoon or evening. Delta is forecast to move into the southeastern Gulf of Mexico Tuesday night or early Wednesday. Maximum sustained winds have increased to near 40 mph (65 km/h) with higher gusts. Additional strengthening is expected during the next few days, and the tropical storm is expected to be a hurricane when it moves near or over western Cuba. Tropical-storm-force winds extend outward up to 45 miles (75 km) from the center. The estimated minimum central pressure is 1004 mb (29.65 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Tropical Storm Delta can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT1, WMO header WTNT41 KNHC, and on the web at www.hurricanes.gov/text/MIATCDAT1.shtml. STORM SURGE: A dangerous storm surge will raise water levels by as much as 3 to 5 feet above normal tide levels along the immediate coast of the Isle of Youth and along the south coast of western Cuba near and to right of where the center makes landfall. Near the coast, the surge will be accompanied by large and dangerous waves. RAINFALL: Through midweek, Delta is expected to produce 3 to 5 inches of rain with isolated maximum totals of 8 inches across Jamaica and western Cuba. This rainfall could lead to significant flash floods and mudslides. Over the Cayman Islands, 2 to 4 inches of rainfall will be possible with this system. WIND: Tropical storm conditions are expected in the Cayman Islands beginning late today. Hurricane conditions are possible within the Hurricane Watch area by Tuesday afternoon, with tropical storm conditions possible by early Tuesday. Tropical Storm conditions are possible in the Tropical Storm Watch area in Cuba by early Tuesday. NEXT ADVISORY ------------- Next complete advisory at 1100 AM EDT. $$ Forecaster Brown

Looks like an inner core is beginning to form. Also looks south of the official estimated position. If this is the case, the next 36 hours are going to be gangbusters.

That's not far off from a hypothetical unfolding. It could reach Cat 4 and then weaken rapidly prior to landfall.

Convection is flaring up nicely over the center. This seems ahead of schedule for TCG. Parameters are favorable for significant intensification by the time this reaches the straits. Could very well be an overperformer, perhaps even a major by the time it reaches the central GOM. Then significant weakening into landfall. If it becomes a large hurricane, significant surge will be the story here.

2018 October, this year is not. Been a number of frontal boundaries and several TCs already in the N. GOM to kill shallow heat content. But as GOL pointed out, SW FL is still very much in play for a major through the remainder of the month. 92L likely won't be the last W. Caribbean system during the next three weeks.

Landfall. Gamma didn't pull off the upgrade. Trivial as far as impacts, but obviously those seasonal numbers.... 000 WTNT65 KNHC 031658 TCUAT5 Tropical Storm Gamma Tropical Cyclone Update NWS National Hurricane Center Miami FL AL252020 1200 PM CDT Sat Oct 03 2020 ...GAMMA MAKES LANDFALL NEAR TULUM, MEXICO... Surface observations and satellite images indicate that the center of Tropical Storm Gamma made landfall in the northeast Yucatan Peninsula near Tulum, Mexico, around 1145 AM CDT. The storm was very close to hurricane strength at landfall, with maximum sustained winds near 70 MPH (110 MPH) with higher gusts. A weather station at Xel-Ha Park, along the Yucatan coast just north of Tulum, reported a sustained wind of 55 mph (89 km/h) and a gust to 68 mph (109 km/h) within the past hour. SUMMARY OF 1200 PM CDT...1700 UTC...INFORMATION --------------------------------------------------- LOCATION...20.2N 87.5W ABOUT 0 MI...0 KM N OF TULUM MEXICO MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...NW OR 315 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...980 MB...28.94 INCHES $$ Forecaster Pasch

92L is quite convectively active this morning. Good divergence and CAPE associated with this system. Additionally there is already good inflow and convergence notable on visible. Yet the ECMWF is yet to do jack squat with this system during lead time just like a few days ago when it missed with Gamma. We shall see.

Getting close.

Dueling CBs within the CDO with enough distance off the Rivera Maya coast that Gamma may very well attain hurricane intensity by landfall. Been a number of these this year.

Unbelievable... Safety first and foremost but damn we've been plagued this year with flight issues. Pun intended.

The 12z GFSv15 does try to develop the current wave in the ECARIB but gets it too close to the Yucatan Peninsula. It is inland too long and also gets bypassed by the trough. The second wave evolves CAG characteristics further west and breaks off into the EPAC. This is of course a single operational run solution but let's go ahead and cancel the remainder of the season. Trollololo... That being said, let's look at the 12z GFSv16 (para). It develops the first wave much quicker south of Cuba near to Jamaica. It also gains enough latitude to get caught into the southwesterlies associated with the digging trough. This turns the first potential TC, at this point a hurricane into and across the Florida Peninsula. Additionally, the para develops the second ITCZ wave out of convergence off Venezuela and then goes bananas, having a second TC bombing out in the NW Caribbean into the long range. Varying solutions but pretty much the overall theme here continues to be increased chances of TCG somewhere in the NW Caribbean. That hasn't really changed. I should also add that this morning's ECMWF ensemble continues to show tight clusters of TCG in the NW Caribbean through the medium range as well. Does this guarantee we'll have a WCARIB hurricane? No, but there's not really anything to prove we won't. Likewise, the season isn't dead. We'll revisit that topic in about five more weeks once the next favorable CCKW has passed.

SSTs are obviously not going to be an issue in the NW Caribbean. There will be some cold fronts that will cool the N. GOM but the SE GOM should remain quite warm for anything that would/could potentially hook into Southwesterly flow and head across the Florida Peninsula. Bigger influences will be stacked vs sheared flow, land influences (Yucatan, Cuba) and how intense a hypothetical TC would become prior to entry into the SE GOM.

Here comes the first wave that has model support. The GFS15 vs 16(para) have varying solutions. The first wave near the Lesser Antilles is much more vigorously modeled by the GFS to become the intense hurricane. The para wants to throw down the gauntlet on the second wave currently out over the MDR. At any rate, chances are we'll have some sort of W. Caribbean action by next weekend. The ECMWF ensembles are increasing support as well for something developing. We're getting closer to the mid range.