| cieldumort |
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| Wed Jun 10 2026 05:15 AM |
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Arthur Lounge
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It is looking increasingly probable that a significant increase in precipitable water, and at least some variation of a mostly to completely closed-off lower-level vort, will be drawn into or reform over the western Gulf later this week from DNA remnants of soon-to-be former East Pac Tropical Storm Cristina, leftovers of former East Pac Tropical Storm Boris, and the general weak gyre-like feature associated with the regional monsoon. More and more, models are on alert for this mix to potentially become our first Atlantic Invest of the year - possibly also bringing significantly enhanced rainfall to portions of Texas and Louisiana that may already be susceptible to flooding after recent rains.
Given that models are almost insistent some type of coherent disturbance will track across central America to resurface in the western Gulf over the next 36-84 hours, we will start a Lounge on this forecast weather-maker (Invest unknown/tbd) at this time.
Below: Globals 925mb winds and relative humidity at 84 hours out from 6/10/0z Cr. Pivotal Weather
Below: EURO AI Ensemble Run 6/10/0z Cr. Weathernerds.org
Below: EURO (Traditional) Ensemble Run 6/10/0z Cr. Weathernerds.org
Below: Google DeepMind FNV3 (GDM-FNV3 is DeepMind's newest ensemble probabilistic machine learning weather model, optimized for cyclones) Cr. Weathernerds.org
6-12-26 7:45AM CT: The title has been updated to reflect that the well-advertised Area of Interest is now in the Bay of Campcheche and will likely soon be Invest tagged.
-Ciel
6-15-26 1:35PM CDT: The disturbance we have been tracking for several days has finally been Invest-tagged, 90L, and the title has been updated accordingly
-Ciel
6-16-26 10:00AM CDT: Advisories have begun on Invest 90L, now PTC ONE (Potential Tropical Cyclone), and the title has been updated.
10:00 AM CDT Tue Jun 16
Location: 27.0°N 98.0°W
Moving: NE at 6 mph
Min pressure: 1007 mb
Max sustained: 30 mph
-Ciel
6-17-26 10:00AM CDT: Recon has confirmed that PTC ONE has become Tropical Storm Arthur, and the title has been updated
-Ciel
CFHC
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| Wed Jun 10 2026 10:53 AM |
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Re: EPAC Vorticity Cross-Over (Invest UNK)
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Cristina model guidance:
Water seems to be the biggest impact here, don't really expect development.
| cieldumort |
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| Wed Jun 10 2026 11:46 AM |
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Re: EPAC Vorticity Cross-Over (Invest UNK)
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| cieldumort |
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| Wed Jun 10 2026 12:44 PM |
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Re: EPAC Vorticity Cross-Over (Invest UNK)
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It now also appears likely that the forecast Area of Interest in the W Gulf will also be getting an assist from an approaching tropical wave, clearly visible in the western Caribbean this morning.
Western Gulf development odds are probably going to get nudged up.
| cieldumort |
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| Wed Jun 10 2026 02:38 PM |
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Re: EPAC Vorticity Cross-Over (Invest UNK)
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The few GDM-FNV3 ensembles that generate a TC from this continue to hold off until early next week while in the vicinity of south Texas, with today's 12z run
It will be helpful if recon does make that trip into the Bay of Campeche Friday
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CFHC
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| Thu Jun 11 2026 10:40 AM |
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Re: EPAC Vorticity Cross-Over (Invest UNK)
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Still a very low chance of anything developing in the Gulf from the trough/Cristina, google deep mind really the only thing developing it still.
However there remains a good potential still for excessive rain across southern and eastern TX early next week for impacts there.
| cieldumort |
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| Thu Jun 11 2026 12:50 PM |
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Re: EPAC Vorticity Cross-Over (Invest UNK) AOI 10%
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Model update: Nearly all of today's 06z, 12z and 15z runs of both the operational Globals and CAMs (Convection Allowing Models) continue to develop a closed low-level area of low pressure in the western Gulf in about 36-48 hours, of varying flavors of weak sauce. However, the western Gulf is a mechanically favored area for genesis and strengthening, often getting underbid by model runs that do not yet have an "Invest" to work off of.
As of this morning, the tropical wave starting to cross Central America from the western Caribbean has begun ingesting the remnant circulation of former east Pac tropical storm Cristina, and this could help jump start things enough for an Invest tag to be added once this conglomeration is in the Gulf. For now, a tentative recon mission into the Bay of Campeche has not been set.
Trends are also being closely monitored for flooding potential, regardless of development.
| cieldumort |
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| Fri Jun 12 2026 01:07 AM |
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Re: EPAC Vorticity Cross-Over (Invest UNK)
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EURO Ensemble implied TD formation probability in the Western Gulf over the next 3 days is now 80%
| cieldumort |
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| Fri Jun 12 2026 01:34 AM |
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Re: EPAC Vorticity Cross-Over (Invest UNK)
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The most recent run of the 3-hour hi-res EURO implies that the area of low pressure/potential TD will be coming inland around Tampico, MX and then lingering around between eastern MX to deep south TX for at least 144 hours (end of run), driving copious moisture into south and coastal Texas for the duration, as well as suggesting potential for some flooding core rain events over eastern through northeastern Mexico.
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CFHC
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| Fri Jun 12 2026 09:52 AM |
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Re: W Gulf Closed Low Invest TBD
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Decent attempt to get a little more organized, still has a lot to overcome, along with time. Very heavy Rain for anywhere it gets over, though. Still very doubtful this ever develops.
Water Vapor Satellite shows the hostile conditions better, and why I don't think it will do much. Dry air ahead of it will limit rainfall effectively to closer to the center and east of it.
It may try to develop, but I don't expect it will succeed.
| cieldumort |
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| Sat Jun 13 2026 04:28 AM |
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Re: W Gulf Closed Low Invest TBD
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A solid Scat pass arrived a while ago that also suggests a closed surface low exists, but that is wonky and elongated ~ and at the time ~ arguably located partially inland ~ south of the Bay of Campeche. Furthermore, most of the disturbance resembles a trof.
Below: analysis from the Tropical Analysis and Forecast Branch (TAFB) June 13 2:22z
Recent Scatterometer data (surface winds):
Despite all of the above, the 1007mb Low continues to very gradually show improved convection, moisture and structure, and very importantly, no longer is it getting beaten up by high levels of dry air and shear. Increasingly, the disturbance finds itself in a moistening environment with upper-level high pressure building in aloft, and the fledgling surface circulation could be getting drawn further into the deeper convection to its north.
If trends continue, and Invest tag will likely be added and vort-centric, "Hurricane," model runs could begin.
| cieldumort |
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| Sat Jun 13 2026 02:03 PM |
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Re: W Gulf Closed Low Invest TBD
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Just east of Tampico, TX this morning. ASCAT shows that while closed, the low is still a bit stretched with limited organized convection, but it continues improving. Time left over water is pivotal for near-term development odds. Modeling favors taking the system into northeast Mexico and lingering it around the MX/TX border for a couple of days, with about half of the models showing the tropical low slowly getting pulled back offshore ~ with another low chance of becoming a TC ~ and roughly the other half having it feeding if not merging with a stationary front draped across the gulf coast states, while inland.
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MikeC
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| Sun Jun 14 2026 12:14 PM |
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Re: W Gulf Closed Low Invest TBD
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As it's over land now, no chance for development, it may ride along the coast and be aided by shear patterns later, but unlikely to develop into anything tropical. It never closed off. Vorticity is more elongated now than it was, so I suspect the 20% may drop down to 10 or go up to 30 later today if it looks like it'll get more time over water. It's going to be difficult to get a named storm before August with the general conditions this year.
| cieldumort |
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| Sun Jun 14 2026 02:01 PM |
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Re: W Gulf Closed Low Invest TBD
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I strongly suspect that it closed off intermittently, but that was its weakness - reverting back to wave/trof too often - might have been able to pull it off with another 24 hours over water. Now that it is over land and barely recognizable, I have more doubts than ever about its chances to become a tropical cyclone, and find it curious that NHC has actually increased development odds to 30% over the next 7 days. The EURO and its ensembles have been bullish, but a lot of that bullishness is actually over land and probably has more to do upper-level support and perhaps also brown ocean biases of that particular model.
| cieldumort |
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| Sun Jun 14 2026 03:30 PM |
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Re: NW Gulf Low Invest TBD
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This rare outcome has happened before, but usually only with already previously well-developed tropical cyclones. EURO and these ensemble members are not the only models or ensembles sniffing out some kind of development and intensification while inland, so probably not something to ignore, but this general outcome would also be rather historic if it verifies
| cieldumort |
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| Sun Jun 14 2026 11:58 PM |
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Re: NW Gulf Low Invest TBD
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Fair to very good outflow in all quadrants above the low/mid-level swirl now in northeast Mexico. In the loop below, one can track the rough outline of the low/mid-level cyclonic (counter-clockwise) rotation by the forward motion of the lightning flashes, and the upper-level outflow in the gray and lighter blues aloft rotating clockwise. It does appear that this system could become a quasi-tropical low even while still inland, which - could - give it a head start should it head back out over the waters of the northwestern Gulf early this coming week.
| cieldumort |
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| Mon Jun 15 2026 02:42 AM |
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Re: NW Gulf Low Invest TBD
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Today's 0z runs of traditional operationals and CAMS for Wednesday morning
| cieldumort |
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| Mon Jun 15 2026 01:08 PM |
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Re: NW Gulf Low Invest TBD
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One might look at this and think models are hallucinating the location of "Disturbance 1." There are several other much bigger actors in play now such that it is possible the original low we have been tracking (and is still being initialized on among the various models and also the NHC) is becoming so absorbed within the much larger monsoon gyre over Mexico that the forecast track east over water simply does not verify, or significantly changes. The most recent forecast discussions are taking this into account, that "Disturbance 1" continues tracking more north than east, within the cyclonic flow of the much larger gyre centered over Mexico (centered west of the tiny yellow "x" in the image below), and helps spawn a new area of surface low pressure over the NW Gulf midweek.
Regardless of the exact outcome, much of Texas, Louisiana, Mississippi and Alabama are in for days of very heavy and often-times dangerously flooding rains this week.
WPC has already introduced four consecutive days of Moderate Risk and may even introduce at least one area of High Risk for flooding.
| cieldumort |
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| Mon Jun 15 2026 02:41 PM |
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Re: INVEST 90L
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Invest tagged while inland, not something we see too often.
2026-06-15 18:00 26.0 -101.0
https://rammb-data.cira.colostate.edu/tc_realtime/storm.asp?storm_identifier=al902026
| cieldumort |
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| Mon Jun 15 2026 02:57 PM |
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Re: INVEST 90L
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Some may ask if a tropical cyclone can form while inland. The answer is not as straight forward as it can seem. Warm-core lows do form over land frequently, but something very close to 100% of these would never be considered tropical cyclone-like. But there are exceptions.
In this situation, both ground and deep layers of the atmosphere are very saturated. Given favorable upper-level support, Invest 90L could, in theory, pull something off even prior to moving offshore (assuming it does move offshore). Definitely interesting to watch, and very dangerous, regardless. There is genuine potential that if 90L does get named (which would be Arthur), this ongoing flooding could be so significant that it ends up being considered for retirement.
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CFHC
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| Mon Jun 15 2026 03:20 PM |
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Re: INVEST 90L
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Euro ensembles very active with 90L here. Vort chart isn't showing it well since the rotation is so small, at least not yet.
Beyond these Ensembles, the GFS keeps it over land, however icon, AI GFS, Canadian do bring it out over the water. The 50/50 seems like a good estimate. Its window to strengthen is short, but the pattern may allow it (with a lot of baroclinic enhancement)
| cieldumort |
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| Mon Jun 15 2026 06:45 PM |
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Re: INVEST 90L
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If 90L does become a Tropical Cyclone, the only noticeably different impact could just be a greater chance of a more consolidated, maximized area of heaviest rainfall ~ but not necessarily the highest totals, as these can be achieved without core rains given the likelihood of ongoing training bands of rain/thunderstorms and the squeezing out of moisture as this system interacts with the impinging front to its north.
Given how saturated both the ground and air is or is becoming in the southern states, combined with strong upper-level exhaust, it may maintain as a Tropical Cyclone for quite a lot longer than expected. Alternatively, it could also encounter too much shear and shred apart. But one thing is certain: flooding.
| cieldumort |
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| Tue Jun 16 2026 01:17 PM |
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Re: PTC ONE Lounge
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After curving more east than north for a while, now PTC ONE is being forecast to take a more northeasterly track, going just barely offshore along the Texas coast.
If a track just offshore of most of if not the entirety of the Texas coastline verifies, ONE would likely have sufficient time over water to be able to organize into
Arthur. This would also lead to several days of additional deep tropical moisture being rotated around the Low into the south.
Above: PTC ONE Track History Image credit: Polarwx.com
Above: Track Guidance image credit: TropicalTidbits.com
| cieldumort |
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| Tue Jun 16 2026 08:05 PM |
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Re: PTC ONE Lounge
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Deep-layer shear is starting to impinge quite a bit on the western side of ONE. It is going to need to move out over the warm gulf water soon so it can have its best chance to develop the deep convection needed to fend it off and begin moving more with the flow so that shear is reduced, especially if a good upper-level outflow channel can develop.
| cieldumort |
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| Tue Jun 16 2026 09:59 PM |
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Re: PTC ONE Lounge
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| cieldumort |
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| Tue Jun 16 2026 10:12 PM |
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Re: PTC ONE Lounge
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Not much in the way of convection as ONE enters the Gulf
| cieldumort |
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| Wed Jun 17 2026 04:36 AM |
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Re: PTC ONE Lounge
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ONE is presently a very sheared cyclone and it may come down to a subjective call as to whether or not to classify it as a Tropical Cyclone this morning, but it seems a close call despite how lousy it looks.
The western semicircle is sheared and exposed with dry air and subsidence. On the other hand, banding has arguably improved in appearance on radar, and while most bands are well east of the center, which is still right on the coast around Corpus Christi, TX, several already are likely producing tropical storm force winds. Furthermore, in the aggregate, models continue supporting further development, with some even suggesting that ONE may become a robust hybrid once back over land, producing a massive swath of heavy and locally flooding rain, at least isolated damaging wind gusts, and potentially several tornadoes and waterspouts.
METAR KGYF 170736Z AUTO 13025G44KT 1 1/4SM -TSRA BR OVC008 24/22 A2969 RMK AO2 LTG DSNT ALQDS T02380222
METAR KGYF 170715Z AUTO 17041KT 7SM -TSRA SCT014 BKN029 OVC043 26/25 A2968 RMK AO2 LTG DSNT ALQDS T02600248
METAR KGYF 170655Z AUTO 17030G35KT 5SM -TSRA BR SCT011 BKN022 OVC036 25/23 A2971 RMK AO2 LTG DSNT ALQDS P0003 T02540234
METAR KGYF 170635Z AUTO 17027G35KT 1 3/4SM TS SCT007 BKN026 OVC038 26/23 A2974 RMK AO2 LTG DSNT ALQDS PWINO T02580230
METAR KGYF 170615Z AUTO 19032G41KT 7SM -TSRA SCT007 BKN038 OVC043 27/25 A2973 RMK AO2 LTG DSNT ALQDS T02730245
METAR KGYF 170555Z AUTO 19031G34KT 5SM -TSRA BR SCT007 SCT014 BKN028 28/26 A2971 RMK AO2 LTG DSNT ALQDS P0016 T02790259 10329 20276 60162
METAR KGYF 170535Z AUTO 17017KT 7SM -TSRA BR BKN005 BKN017 OVC060 28/26 A2973 RMK AO2 LTG DSNT ALQDS P0016 T02770255
METAR KGYF 170515Z AUTO 19025G29KT 5SM -TSRA BR OVC005 31/29 A2972 RMK AO2 LTG DSNT ALQDS P0016 T0306////
METAR KGYF 170455Z AUTO 25020G49KT 210V290 1 1/4SM +TSRA BR OVC005 29/26 A2972 RMK AO2 VIS 1/2V2 1/2 LTG DSNT ALQDS P0140 T02850262
| cieldumort |
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| Wed Jun 17 2026 11:39 AM |
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Re: Arthur Lounge
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Overall, several of the more traditional models' ensembles, such as the EURO's EPS, performed fairly well and arguably better than the GDM (Google DeepMind) with regard to both development and intensity. GDM had only a very few of its ensemble members showing development at all. However, of the GDM members that did, they performed far better than traditionals for where genesis would occur.
As for future track and intensity, here are a few of the most recent runs (Images and plots credit: polarwx.com):
| cieldumort |
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| Wed Jun 17 2026 04:19 PM |
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Re: Arthur Lounge
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We may be starting to see some center reformations that could track with the most recent GDM ensemble run from 12z
| cieldumort |
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| Wed Jun 17 2026 08:35 PM |
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Re: Arthur Lounge
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| cieldumort |
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| Wed Jun 17 2026 08:49 PM |
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Re: Arthur Lounge
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Modeling for Thursday evening (6-19-26-0z). Arthur or Arthur's remnants still producing significant weather.
| cieldumort |
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| Wed Jun 17 2026 08:54 PM |
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Re: Arthur Lounge
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Modeling for midday Friday (6-19-26-18z). Arthur/Arthur's remnants entering western Atlantic. May be redeveloping.
