MED: ZORBAS - Hurricane over the Mediterranean Sea
Moderator: S2k Moderators
- Vince_and_Grace_fan
- Category 1
- Posts: 315
- Joined: Thu Nov 03, 2016 9:25 am
- Location: Szombathely (Hungary)
MED: ZORBAS - Hurricane over the Mediterranean Sea
By the end of the week, another and possibly much stronger tropical sysem can form over the Central Mediterranean Sea.
Some of the models are very bullish and strengthen it into a hurricane.
Arpege :
ICON:
ECMWF:
Some of the models are very bullish and strengthen it into a hurricane.
Arpege :
ICON:
ECMWF:
4 likes
Re: Another tropical system over the MED Sea
Amazing model output, all models I've seen have a bona fide tropical storm, some produc a legitimate hurricane. It is also sustained for a period of time.
So let's see... SSTs are currently high enough to support a tropical cyclone as well, and it's undoubtably warm cored on nearly all models.
So let's see... SSTs are currently high enough to support a tropical cyclone as well, and it's undoubtably warm cored on nearly all models.
1 likes
Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products
-
- Category 5
- Posts: 4966
- Joined: Wed Nov 14, 2012 10:43 am
Re: Another tropical system over the MED Sea
I've never seen anything like that in the Mediterranean. Very good model consensus on track and intensity only 3 days until development. 00z EC has it intensify into a hurricane near Crete followed by a landfall over Turkey. It then tracks into the Black Sea and possibly reintensify some before final landfall on Ukraine. Will it be the storm of the century for Mediterranean sea?
1 likes
-
- Category 5
- Posts: 4966
- Joined: Wed Nov 14, 2012 10:43 am
Re: Another tropical system over the MED Sea
00z EC destroys western Crete with sustanied hurrricane condition and stronger gusts on higher elevations.
2 likes
- wxman57
- Moderator-Pro Met
- Posts: 22484
- Age: 66
- Joined: Sat Jun 21, 2003 8:06 pm
- Location: Houston, TX (southwest)
Re: Another tropical system over the MED Sea
Satellite has a weak low offshore Libya west of Benghazi already. Not much convection, but it could be the system that the models are developing. SSTs there are 27 to 27.5C (80-81 degrees F).
3 likes
Re: Another tropical system over the MED Sea
I think if a strong and destructive tropical cyclone forms in the Med, creating a TCWC would have to be considered (or extension of the NHC's AOR)
2 likes
Re: Another tropical system over the MED Sea
If this does happen, would ACE go to the Atlantic assuming it generates?
0 likes
The above post and any post by Ntxw is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including Storm2k. For official information, please refer to NWS products.
- Vince_and_Grace_fan
- Category 1
- Posts: 315
- Joined: Thu Nov 03, 2016 9:25 am
- Location: Szombathely (Hungary)
Re: Another tropical system over the MED Sea
wxman57 wrote:Satellite has a weak low offshore Libya west of Benghazi already. Not much convection, but it could be the system that the models are developing. SSTs there are 27 to 27.5C (80-81 degrees F).
http://wxman57.com/images/med.JPG
I think this is the remnants of the last cyclone (or at least it's associated with it). It prduced temporary paches of deep convection yesterday and today morning.
Our cyclone expected to form near the coast of NE Libya on Thursday, helped by a cut-off upper level low that will reach the area (but it will quickly weaken thereafter).
0 likes
Re: Another tropical system over the MED Sea
When do you think Mediterranean Hurricane Seasons with 3 or more storms each year become common. The last one just died!
0 likes
- TheAustinMan
- Category 5
- Posts: 1007
- Age: 24
- Joined: Mon Jul 08, 2013 4:26 pm
- Location: United States
- Contact:
Re: Another tropical system over the MED Sea
Ah yes this is perhaps the weather event that has piqued my interest most this week. Model support on controls and ensemble guidance is in excellent consensus across the board over the development of an organized low in the Mediterranean Sea. Looks like they also came into better agreement today over track with an expected course through the Aegean Sea, though I did see some ensembles diving southward into Libya.
0 likes
Re: Another tropical system over the MED Sea
Excellent discussion of the genesis process of this potential system issued by ESTOFEX:
Source: http://www.estofex.org/
This extended outlook was mainly issued due to the augmented probabilities for a gradually developing warm-core cyclone south of the Ionian Sea.
Anticyclonic Rossby-wave breaking is en route over SE Europe with the main vorticity lobe departing east over E Europe, leaving behind an elongated and gradually constricting PV streamer over the Ionian Sea and Greece. This cut-off process is accompanied by rather chilly mid-levels, which overspread the warm Ionian Sea (latest readings of the Advanced Very High Resolution Radiometer indicating SST values in the 26-28 C range with increasing values to the south). The main source for LL cyclogenesis is found along a tightening baroclinic zone in the SE quadrant of that mid/upper vortex.
IFS had persistent signals of this scenario during its past few runs and latest model suite including GFS and ICON joined that scenario with ongoing zonal variations of where LL cyclogenesis may occur. However all models place the evolving LL vortex in the same synoptic environment, which
would indeed support vigorous intensification as proposed f.ex. by IFS due to
- a tightening/deep temperature gradient
- persistent QG forcing along the E quadrant of the cut-off
- improving upper divergence over the baroclinic zone especially during the night
- a northward advected pool of warm/moist air with SBCAPE in the 500-1000 J/kg range, interacting with the evolving vortex.
Following past hints on phase diagrams, a developing shallow warm-core cyclone is possible. Still ongoing augmented but gradually weakening DLS next to the PV streamer and probably pulsating convection (also displaced from the vortex' center) would support a gradually structuring shallow warm-core structure until 06Z. This idea is supported by most models with GFS the less aggressive and IFS the most aggressive one (excluding fine-mesh models). But even the IFS has a tilted LL/mid-level vortex with warm-core signatures mainly below 700 hPa at 06 UTC, so confidence increases that until 06 UTC nothing more than a shallow warm core structure is the most likely outcome - if at all (probabilities for a deeper warm-core cyclone increase beyond 06 UTC).
The vortex will push N/NW, east of the southbound moving cut-off. The final track remains uncertain with ongoing 500 hPa ensemble spread regarding the path of the cut-off but also due to uncertainties how deep/structured the vortex will be until 06 UTC. For now no level area was issued with mentioned uncertainties, a weakening CAPE/shear overlap betimes and a rainfall threat, which stays mainly offshore until 06 Z. Crete will be monitored for an upgrade if the vortex shifts more east (which is constantly proposed by GFS).
Anticyclonic Rossby-wave breaking is en route over SE Europe with the main vorticity lobe departing east over E Europe, leaving behind an elongated and gradually constricting PV streamer over the Ionian Sea and Greece. This cut-off process is accompanied by rather chilly mid-levels, which overspread the warm Ionian Sea (latest readings of the Advanced Very High Resolution Radiometer indicating SST values in the 26-28 C range with increasing values to the south). The main source for LL cyclogenesis is found along a tightening baroclinic zone in the SE quadrant of that mid/upper vortex.
IFS had persistent signals of this scenario during its past few runs and latest model suite including GFS and ICON joined that scenario with ongoing zonal variations of where LL cyclogenesis may occur. However all models place the evolving LL vortex in the same synoptic environment, which
would indeed support vigorous intensification as proposed f.ex. by IFS due to
- a tightening/deep temperature gradient
- persistent QG forcing along the E quadrant of the cut-off
- improving upper divergence over the baroclinic zone especially during the night
- a northward advected pool of warm/moist air with SBCAPE in the 500-1000 J/kg range, interacting with the evolving vortex.
Following past hints on phase diagrams, a developing shallow warm-core cyclone is possible. Still ongoing augmented but gradually weakening DLS next to the PV streamer and probably pulsating convection (also displaced from the vortex' center) would support a gradually structuring shallow warm-core structure until 06Z. This idea is supported by most models with GFS the less aggressive and IFS the most aggressive one (excluding fine-mesh models). But even the IFS has a tilted LL/mid-level vortex with warm-core signatures mainly below 700 hPa at 06 UTC, so confidence increases that until 06 UTC nothing more than a shallow warm core structure is the most likely outcome - if at all (probabilities for a deeper warm-core cyclone increase beyond 06 UTC).
The vortex will push N/NW, east of the southbound moving cut-off. The final track remains uncertain with ongoing 500 hPa ensemble spread regarding the path of the cut-off but also due to uncertainties how deep/structured the vortex will be until 06 UTC. For now no level area was issued with mentioned uncertainties, a weakening CAPE/shear overlap betimes and a rainfall threat, which stays mainly offshore until 06 Z. Crete will be monitored for an upgrade if the vortex shifts more east (which is constantly proposed by GFS).
Source: http://www.estofex.org/
1 likes
- AJC3
- Admin
- Posts: 3873
- Age: 60
- Joined: Tue Aug 31, 2004 7:04 pm
- Location: West Melbourne, Florida
- Contact:
Re: Another tropical system over the MED Sea
Ntxw wrote:If this does happen, would ACE go to the Atlantic assuming it generates?
ACE from Medicanes has never been used as a contribution to the seasonal Atlantic basin ACE. It would skew the data (slightly) unless a comprehensive (and exhaustive) TC BT/climatology were done for the MEDSEA dating back through the entire satellite era (and then some). I know a couple friends, one in particular (an S2K member ) who could easily make this a PhD dissertation if he wanted, seeing how (IMO) he's a SME on Medicanes.
4 likes
Re: Another tropical system over the MED Sea
Another very interesting forecast discussion by ESTOFEX forecaster Helge Tuschy:
Source: http://www.estofex.org/
Extended Forecast
Valid: Fri 28 Sep 2018 06:00 to Sat 29 Sep 2018 06:00 UTC
Issued: Wed 26 Sep 2018 20:13
Forecaster: TUSCHY
SYNOPSIS and DISCUSSION
This extended forecast was issued mainly due to the risk of a potential (shallow) warm-core cyclone south of and over the S-Ionian Sea.
On Friday morning, an extensive cut-off will be centered over the Ionian Sea and further south. During the day a gradual turn to the NE is anticipated as this cut-off is forecast to get caught up by another strong upper trough over NE Europe, which approaches SE Europe during the night.
Despite this general agreement regarding the synoptic evolution, global models like IFS, GFS and ICON continue to diverge substantially regarding the exact structure of the deep vortex over the S-Ionian Sea which will be crucial regarding the track forecast of the intensifying LL vortex. ICON breaks the vortex into numerous smaller-scale mid/upper vortices, GFS shows a broadening upper vortex lifting NE towards Greece and IFS expecting an intense/deep vortex E of Sicily with a new upper vortex evolving to its NE (over Greece). Combined with different handling on the intensity of the LL vortex it is not of surprise to see an ongoing substantial model spread regarding the cyclone's track: IFS steering the LL vortex towards Sicily, whereas GFS and ICON indicating a drift to the N and NE (towards Greece), which is in line with the general lifting trend of the upper vortex (all track forecasts until Saturday 06 UTC only).
Latest WV data highlights a significant tropopause fault with the intrusion of very dry mid/upper air along the W/NW fringe of the cut-off (sampled well by Brindisi, 26th September at 12 UTC). Until Friday this dry air and attendant upper level jet maximum are forecast to circle the deep vortex and both will push NE towards Crete and the Aegean Sea, cutting off a pool of warm/moist and unstable air to the west (beneath the mid/upper vortex). SBCAPE will be in the 500-1000 J/kg range and supportive for vigorous convective activity. However, upper divergence starts to weaken over the S-Ionian Sea as the upper jet pushes NE and away from the main vortex. With decreasing baroclinicity and shear, the main driver of the LL vortex strength becomes the convection, which starts to organize during the forecast period (here organized convection means convective banding and not rotating updrafts!). Abating divergence could be a crucial point regarding a slow-down of convective activity and attendant organization into convective bands.
Latest phase diagrams remain somehow reluctant regarding the speed of the transformation of the thermal structure, but still indicate a shallow warm-core structure (excluding IFS, which continues to advertise a deeper warm-core anomaly). Uncertainties regarding the intensifiaction rate and strength of the LL vortex depend on:
- the potential of better upper-level ventilation to the NE into the upper jet which also depends on the final structure of the upper level vortex
- how broad the LL vortex will be with a smaller vortex susceptible to more rapid intensity changes (up and down)
The first point is not yet supported by all global models due to the different geometry of the geopotential height fields. The second point seems to be crucial as ICON and GFS prefer a broader LL circulation which would need more time for intensification, whereas IFS already starts the forecast with a compact vortex which could intensify much faster. ASCAT data will give more and helpful input into that topic as the vortex forms but for now we lean more towards ICON/GFS (slower intensification rate) given the large nature of the upper vortex and the persistent forecasts of both models during the past few days regarding the size of the LL vortex (plus abating divergence).
Otherwise the background environment remains favorable with SSTs of 26-28C (above climatology), weak DLS next to the evolving LL vortex and deep moist profiles with elongated thin CAPE profiles.
Mentioned uncertainties preclude confined areas with higher probabilities for now but the main risk will be excessive rain, severe wind gusts (mainly driven by the ageostrophic response to the deepening depression) and isolated tornadoes. Further model data will be evaluated to determine certain areas with an higher severe risk, especially if a potential landfall becomes clearer.
Valid: Fri 28 Sep 2018 06:00 to Sat 29 Sep 2018 06:00 UTC
Issued: Wed 26 Sep 2018 20:13
Forecaster: TUSCHY
SYNOPSIS and DISCUSSION
This extended forecast was issued mainly due to the risk of a potential (shallow) warm-core cyclone south of and over the S-Ionian Sea.
On Friday morning, an extensive cut-off will be centered over the Ionian Sea and further south. During the day a gradual turn to the NE is anticipated as this cut-off is forecast to get caught up by another strong upper trough over NE Europe, which approaches SE Europe during the night.
Despite this general agreement regarding the synoptic evolution, global models like IFS, GFS and ICON continue to diverge substantially regarding the exact structure of the deep vortex over the S-Ionian Sea which will be crucial regarding the track forecast of the intensifying LL vortex. ICON breaks the vortex into numerous smaller-scale mid/upper vortices, GFS shows a broadening upper vortex lifting NE towards Greece and IFS expecting an intense/deep vortex E of Sicily with a new upper vortex evolving to its NE (over Greece). Combined with different handling on the intensity of the LL vortex it is not of surprise to see an ongoing substantial model spread regarding the cyclone's track: IFS steering the LL vortex towards Sicily, whereas GFS and ICON indicating a drift to the N and NE (towards Greece), which is in line with the general lifting trend of the upper vortex (all track forecasts until Saturday 06 UTC only).
Latest WV data highlights a significant tropopause fault with the intrusion of very dry mid/upper air along the W/NW fringe of the cut-off (sampled well by Brindisi, 26th September at 12 UTC). Until Friday this dry air and attendant upper level jet maximum are forecast to circle the deep vortex and both will push NE towards Crete and the Aegean Sea, cutting off a pool of warm/moist and unstable air to the west (beneath the mid/upper vortex). SBCAPE will be in the 500-1000 J/kg range and supportive for vigorous convective activity. However, upper divergence starts to weaken over the S-Ionian Sea as the upper jet pushes NE and away from the main vortex. With decreasing baroclinicity and shear, the main driver of the LL vortex strength becomes the convection, which starts to organize during the forecast period (here organized convection means convective banding and not rotating updrafts!). Abating divergence could be a crucial point regarding a slow-down of convective activity and attendant organization into convective bands.
Latest phase diagrams remain somehow reluctant regarding the speed of the transformation of the thermal structure, but still indicate a shallow warm-core structure (excluding IFS, which continues to advertise a deeper warm-core anomaly). Uncertainties regarding the intensifiaction rate and strength of the LL vortex depend on:
- the potential of better upper-level ventilation to the NE into the upper jet which also depends on the final structure of the upper level vortex
- how broad the LL vortex will be with a smaller vortex susceptible to more rapid intensity changes (up and down)
The first point is not yet supported by all global models due to the different geometry of the geopotential height fields. The second point seems to be crucial as ICON and GFS prefer a broader LL circulation which would need more time for intensification, whereas IFS already starts the forecast with a compact vortex which could intensify much faster. ASCAT data will give more and helpful input into that topic as the vortex forms but for now we lean more towards ICON/GFS (slower intensification rate) given the large nature of the upper vortex and the persistent forecasts of both models during the past few days regarding the size of the LL vortex (plus abating divergence).
Otherwise the background environment remains favorable with SSTs of 26-28C (above climatology), weak DLS next to the evolving LL vortex and deep moist profiles with elongated thin CAPE profiles.
Mentioned uncertainties preclude confined areas with higher probabilities for now but the main risk will be excessive rain, severe wind gusts (mainly driven by the ageostrophic response to the deepening depression) and isolated tornadoes. Further model data will be evaluated to determine certain areas with an higher severe risk, especially if a potential landfall becomes clearer.
Source: http://www.estofex.org/
1 likes
- 1900hurricane
- Category 5
- Posts: 6044
- Age: 33
- Joined: Fri Feb 06, 2015 12:04 pm
- Location: Houston, TX
- Contact:
Re: Another tropical system over the MED Sea
1 likes
Contract Meteorologist. TAMU & MSST. Fiercely authentic, one of a kind. We are all given free will, so choose a life meant to be lived. We are the Masters of our own Stories.
Opinions expressed are mine alone.
Follow me on Twitter at @1900hurricane : Read blogs at https://1900hurricane.wordpress.com/
Opinions expressed are mine alone.
Follow me on Twitter at @1900hurricane : Read blogs at https://1900hurricane.wordpress.com/
Re: Another tropical system over the MED Sea
Still large uncertainties with the track and exact formation location. Most models push this eastwards into Greece or Crete on Saturday but still some uncertainties. My guess would be a 45-50kt TS but as Esotfax says with this type of system there could be large swings.
If it does get strong, expect it to look like those far N Atlantic hurricanes.
If it does get strong, expect it to look like those far N Atlantic hurricanes.
0 likes
Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products
- Nightwatch
- Tropical Storm
- Posts: 107
- Joined: Thu Aug 04, 2011 6:58 am
Re: Another tropical system over the MED Sea
HIRLAM model going for cat.1 hurricane
1 likes
The only thing we really get for free is the weather...
-
- Category 5
- Posts: 4966
- Joined: Wed Nov 14, 2012 10:43 am
Re: Another tropical system over the MED Sea
The system is starting to take shape off the coast of Libya
0 likes
-
- Category 4
- Posts: 913
- Joined: Thu Aug 02, 2018 5:29 pm
- Location: Madison, WI
Re: Another tropical system over the MED Sea
Very interesting and certainly unusual, but maybe not as rare as most people think. Besides its higher latitude, the Mediterranean just doesn't seem large enough for a TC to develop without sucking in dry air from the continents, especially the arid North Africa (which is probably why it isn't common, and they usually don't get very strong).
0 likes
Re: Another tropical system over the MED Sea
SconnieCane wrote:Very interesting and certainly unusual, but maybe not as rare as most people think. Besides its higher latitude, the Mediterranean just doesn't seem large enough for a TC to develop without sucking in dry air from the continents, especially the arid North Africa (which is probably why it isn't common, and they usually don't get very strong).
I suspect that is part of the reason why these systems usually remain on the small side, due to the dry air nearby limiting the convective size, like what we saw with Beryl earlier this year.
0 likes
Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products
Re: MED: ZORBAS - Subtropical Storm over the Mediterranean Sea
The first ESTOFEX Mesoscale Discussion has been issued for this system which now already has formed. If I understand the following correctly, they predict a hurricane-strength landfall on the southern part of the Peloponnese peninsula. 30 m/s equate to around 65 kt 1-minute sustained winds.
Source: http://www.estofex.org/
Mesoscale Discussion
Valid: Thu 27 Sep 2018 21:00 to Fri 28 Sep 2018 09:00 UTC
Issued: Thu 27 Sep 2018 20:35
Forecaster: ESTOFEX
This is the first of a series of Mesoscale Discussions issued for a cyclone that is primarily driven by convection. They will be issued twice daily before 9, and 21 UTC until the cyclone dissipates or becomes extratropical. This Mesocale Discussion is not an official product and does not substitute any warnings from National Meteorological Services. We welcome any feedback at inflow@estofex.org.
System: 2018M02
At 27 SEP 18 UTC the centre was located near 32.8N and 18.7E
Estimated minimum pressure: 1004 mb.
Maximum sustained winds: 20 m/s (40 kt, 70 km/h).
Maximum gusts: 25 m/s (50 kt, 90 km/h).
ANALYSIS
A closed low-level circulation has formed near 32.8N and 18.7E, as predicted by most of the global model guidance. The system bears subtropical characteristics as the low-level circulation is exposed and convection is occurring in a band NW and one located 5-8 degrees east of the low-level centre. Furthermore, strong baroclinity is present associated with a southwesterly mid-/upper-level jet to the SW of the centre. The minimum pressure is estimated from a combination of the higher resolution models and the Hebert-Poteat method yielding an ST number between 2.5 and 3.0. The maximum winds occur in the northern hemicircle and are estimated to be near 20 m/s (40 kts) gusting to 25 m/s (50 kts).
FORECAST
Models predict a north-northwestward motion during the first 12 hours and later slow the cyclone down over the Central Ionean sea. After 24 hours an eastward motion should commence that bring it near the Peloponnese Saturday evening. Model consensus slows down the cyclone a bit as it moves over or just south of Peloponnese, producing very heavy rainfall there. After 48 hours, ECMWF accelerates the cyclone ENEwards towards Turkey, whereas ICON and GFS predict slower motion. The track forecast is a consensus of these models.
The intensity of the cyclone is modelled quite differently by various models during previous days. UKMO deepends the cyclone to below 985 before landfall in the Peloponnese while ECMWF, ARPEGE and ICON are less intense. GFS forecasts reintensification after 48 hours over the Aegean, and other models keep the intensity steady, except for ECWMF that weakens it as it accelerates it east-northeastward. The ultimate intensity after 48 hours will depend strongly on the amount of interaction with the mountains of the Peloponnese. The intensity forecast is a blend of the models.
Impacts from strong storm force winds are expected when the cyclone makes landfall on the Peloponnese. Rainfall, however is the biggest threat. Amounts of 200-300 mm can be expected on Saturday and Sunday across the Peloponnese, 125-250 mm over Attica, Eastern Central Greece and the Cyclades, and 50-125 mm over southern Crete. Given that enhanced low-level shear, a few tornadoes may occur over the Greek mainland and the Cyclades on Saturday and Sunday. After Sunday, hazards related to the storm, especially extreme precipitation, could affect western Turkey.
Forecast:
FH DATE & TIME LOCATION PRESS WIND GUSTS
00 27 SEP 1800 UTC 33.0N 18.7E 1003 mb 20 m/s 25 m/s
12 28 SEP 0600 UTC 34.8N 18.2E 996 mb 25 m/s 30 m/s
24 28 SEP 1800 UTC 35.3N 18.5E 994 mb 25 m/s 30 m/s
36 29 SEP 0600 UTC 36.2N 20.8E 992 mb 30 m/s 40 m/s
48 29 SEP 1800 UTC 37.1N 23.2E 996 mb 25 m/s 30 m/s
60 30 SEP 0600 UTC 37.5N 25.2E 997 mb 25 m/s 30 m/s
72 30 SEP 1800 UTC 38.0N 26.0E 999 mb 25 m/s 30 m/s
Valid: Thu 27 Sep 2018 21:00 to Fri 28 Sep 2018 09:00 UTC
Issued: Thu 27 Sep 2018 20:35
Forecaster: ESTOFEX
This is the first of a series of Mesoscale Discussions issued for a cyclone that is primarily driven by convection. They will be issued twice daily before 9, and 21 UTC until the cyclone dissipates or becomes extratropical. This Mesocale Discussion is not an official product and does not substitute any warnings from National Meteorological Services. We welcome any feedback at inflow@estofex.org.
System: 2018M02
At 27 SEP 18 UTC the centre was located near 32.8N and 18.7E
Estimated minimum pressure: 1004 mb.
Maximum sustained winds: 20 m/s (40 kt, 70 km/h).
Maximum gusts: 25 m/s (50 kt, 90 km/h).
ANALYSIS
A closed low-level circulation has formed near 32.8N and 18.7E, as predicted by most of the global model guidance. The system bears subtropical characteristics as the low-level circulation is exposed and convection is occurring in a band NW and one located 5-8 degrees east of the low-level centre. Furthermore, strong baroclinity is present associated with a southwesterly mid-/upper-level jet to the SW of the centre. The minimum pressure is estimated from a combination of the higher resolution models and the Hebert-Poteat method yielding an ST number between 2.5 and 3.0. The maximum winds occur in the northern hemicircle and are estimated to be near 20 m/s (40 kts) gusting to 25 m/s (50 kts).
FORECAST
Models predict a north-northwestward motion during the first 12 hours and later slow the cyclone down over the Central Ionean sea. After 24 hours an eastward motion should commence that bring it near the Peloponnese Saturday evening. Model consensus slows down the cyclone a bit as it moves over or just south of Peloponnese, producing very heavy rainfall there. After 48 hours, ECMWF accelerates the cyclone ENEwards towards Turkey, whereas ICON and GFS predict slower motion. The track forecast is a consensus of these models.
The intensity of the cyclone is modelled quite differently by various models during previous days. UKMO deepends the cyclone to below 985 before landfall in the Peloponnese while ECMWF, ARPEGE and ICON are less intense. GFS forecasts reintensification after 48 hours over the Aegean, and other models keep the intensity steady, except for ECWMF that weakens it as it accelerates it east-northeastward. The ultimate intensity after 48 hours will depend strongly on the amount of interaction with the mountains of the Peloponnese. The intensity forecast is a blend of the models.
Impacts from strong storm force winds are expected when the cyclone makes landfall on the Peloponnese. Rainfall, however is the biggest threat. Amounts of 200-300 mm can be expected on Saturday and Sunday across the Peloponnese, 125-250 mm over Attica, Eastern Central Greece and the Cyclades, and 50-125 mm over southern Crete. Given that enhanced low-level shear, a few tornadoes may occur over the Greek mainland and the Cyclades on Saturday and Sunday. After Sunday, hazards related to the storm, especially extreme precipitation, could affect western Turkey.
Forecast:
FH DATE & TIME LOCATION PRESS WIND GUSTS
00 27 SEP 1800 UTC 33.0N 18.7E 1003 mb 20 m/s 25 m/s
12 28 SEP 0600 UTC 34.8N 18.2E 996 mb 25 m/s 30 m/s
24 28 SEP 1800 UTC 35.3N 18.5E 994 mb 25 m/s 30 m/s
36 29 SEP 0600 UTC 36.2N 20.8E 992 mb 30 m/s 40 m/s
48 29 SEP 1800 UTC 37.1N 23.2E 996 mb 25 m/s 30 m/s
60 30 SEP 0600 UTC 37.5N 25.2E 997 mb 25 m/s 30 m/s
72 30 SEP 1800 UTC 38.0N 26.0E 999 mb 25 m/s 30 m/s
Source: http://www.estofex.org/
2 likes
Who is online
Users browsing this forum: No registered users and 24 guests