Global model runs discussion

[T'Bonz]

I'm up in Tampa helping out the kiddo and the local met seems to believe that something wicked this way will come next week.

Lucky I'm going back down to FLL mid-week.

[Rainband]

I'm up in Tampa helping out the kiddo and the local met seems to believe that something wicked this way will come next week.

Lucky I'm going back down to FLL mid-week.

denis phillips said we have to keep an eye on it. So I am.

[WeatherEmperor]

00Z GFS now drops the Caribbean development but it does show lower pressures in the area.

It is now closer to the Euro in terms of developing a system by the Bahamas/FL Straights. A bit stronger on this run compared to 18Z and moves it NNW along the FL east coast and eventually into the SE Coast.

[WeatherEmperor]

00Z Nogaps and 00Z CMC are now the only models showing the Caribbean development. CMC hits the FL Keys as a TS/Cat1. Nogaps goes into the FL Straights. Waiting for tonight's Euro...

00Z CMC:


Uploaded with ImageShack.us

00Z Nogaps:


Uploaded with ImageShack.us

[WeatherEmperor]

00Z Euro is out. It develops a system in the Yucatan Channel and hits the Florida Big Bend area as a TD/TS. It looks like it initially comes from the NW Caribbean but does not develop until it hits the Yucatan Channel. So now the Euro, CMC and Nogaps show development coming from the NW Caribbean. Good night!!



Uploaded with ImageShack.us

[WeatherWiseGuy]

000
FXUS62 KMLB 040725
AFDMLB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
325 AM EDT TUE OCT 4 2011

.DISCUSSION...
TODAY/TONIGHT...A LITTLE STRONGER ENE FLOW IS ON TAP TODAY AS THE
LARGE CONUS SFC RIDGE FILLS IN ACROSS THE ERN CONUS BEHIND THE
DEPARTING DEEP LAYER NERN CONUS LOW. LOW LEVEL MOISTURE LOOKS TO BE
SHALLOW...RESULTING IN PARTLY TO MOSTLY SUNNY SKIES WITH MAX TEMPS
IN THE L80S COASTAL AND M80S INLAND. OVERNIGHT MINS A BIT HIGHER...
ESPECIALLY ALONG THE COAST...AS BLYR FLOW WILL BE A BIT STRONGER AS
WELL. L-M60S WELL INLAND TO U60S COASTAL VOLUSIA AND L70S ALONG THE
IMMEDIATE SPACE/TREASURE COASTS.

WED-FRI...MORE ACTIVE WEATHER PERIOD UNFOLDING ACROSS THE PENINSULA
WITH AN EXPECTED EVOLUTION TO A HIGHLY AMPLIFIED FLOW PATN ACROSS
THE CONUS AT MIDWEEK. A LARGE SFC HIGH BUILDING SWD ALONG THE ERN
SEABOARD WL ACT TO INCREASE ONSHORE WINDS WED INTO THU WITH VEERING
TENDENCY TO LL WINDS INCREASING MOISTURE ALONG WITH HIGHER RAIN
CHCS THU INTO FRI. BREEZY CONDS DURING FRI WITH DEVELOPMENT OF
STOUT ONSHORE GRADIENT ASCD WITH BUILDING HIGH CENTER NEAR THE MID
ATLC COAST AND LOWER HGHTS OVER THE CARIB BASIN. SCT MARINE SOURCE
SHOWERS SPREADING WELL INLAND THU/FRI WITH GENERALLY UNSETTLED
PATTERN DUE TO FALLING HGHTS INVOF STATE.

EXTENDED...A CONSENSUS OF GUID ACROSS THE EAST CONTINUES TO POINT
TOWARD DEVELOPMENT OF A BLOCKING PATTERN OVER THE EASTERN CONUS
INTO NEXT WEEK WITH HGHT FALLS AND THE POSSIBILITY OF SFC CYCLONE
GENESIS OCCURRING EITHER OVER THE EASTERN GULF TO NEAR THE SRN FL
PENINSULA. THIS IS A MORE WESTERN PLACEMENT TO WHAT WAS DEPICTED
ON MONDAY.

DGEX/CMC ARE MORE ROBUST ATTM WITH DEPTH OF SFC CYCLONE DEVELOPMENT S
OR JUST W OF SRN FL EARLY IN THE WEEK AND LIFTING NWD...WITH
GFS/ECMWF INDICATING WAVE/WEAKER SFC FEATURE. THERE EXISTS HIGHER
DEGREE OF CONFIDENCE ON SLOW MOVING UPR CYCLONE AND A CERTAIN
DURATION OF UNSETTLED WEATHER LOOKS LIKELY DURING THE WEEKEND INTO
EARLY NEXT WEEK WITH A MENTION OF EMBEDDED THUNDER AS WELL DURING
THE WEEKEND ASCD WITH RATHER DEEP MOISTURE AND COOLING ALOFT.

ALTHOUGH DEGREE OF SFC FEATURE EVOLUTION REMAINS UNCERTAIN HAVE
RAISED POPS DURING THE WEEKEND AND EARLY WEEK TO ACCOUNT FOR THE
LIKELIHOOD OF RAIN PRODUCING MECHANICS IN THE LOCAL AREA. MOST
NOTEWORTHY WILL BE A RATHER LONG PERIOD OF STOUT ONSHORE WINDS
WHICH WL PRODUCE SOME BEACH EROSION AND LARGE POUNDING WAVES LATE
IN THE WEEK INTO EARLY NEXT WEEK.

[floridasun78]

EXTENDED FORECAST...
THE LONG RANGE MODELS ARE STILL SHOWING THAT THE HIGH OVER THE
TENNESSEE VALLEY WILL MOVE SLOWLY EAST INTO THE MID ATLANTIC
STATES THIS WEEKEND. THE LONG RANGE MODELS ARE ALSO STILL UNCERTAIN
TO ANY DEVELOPMENT OF LOW PRESSURE IN THE REGION OF SOUTH FLORIDA
ALONG THE STATIONARY FRONT OVER THE FLORIDA KEYS. SO WILL CONTINUE
THE NORTHEAST BREEZY TO WINDY CONDITIONS OVER THE CWA THIS
WEEKEND WITH ISOLATED TO SCATTERED SHOWERS FOR MOST OF THE AREA.
THE ONLY EXCEPTION TO THIS IS THAT THE EAST COAST AND THE ATLANTIC
WATERS COULD ALSO SEE A FEW THUNDERSTORMS THIS WEEKEND...DUE TO
THE LITTLE BIT DEEPER MOISTURE IN PLACE.

AT THIS TIME...IT DOES NOT LOOK LIKE A HEAVY RAINFALL EVENT THIS
WEEKEND OVER SOUTH FLORIDA AS THE LONG RANGE MODELS DO NOT SHOW
ANY SYNOPTIC FORCING OVER THE AREA. THE STEERING FLOW WILL ALSO BE
FROM THE NORTHEAST TO EAST AROUND 20 KNOTS WHICH IN TURN WILL
CAUSE ANY SHOWERS OR THUNDERSTORMS THAT DO DEVELOP TO MOVE VERY
QUICKLY ACROSS THE AREA LIMITING THE DURATION OF RAINFALL.
THEREFORE WILL REMOVE THE HEAVY RAINFALL WORDING FROM THE EXTENDED
HWO SECTION.

miami weather office not jumping on models that show area form by south fl

[cycloneye]

This morning's discussion of potential development by Rob of Crown Weather:

The following post 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.org. For Official Information please refer to the NHC and NWS products.

Tropical Or Sub-Tropical Development A Strong Possibility Starting This Weekend Between The Florida Straits & The Western Caribbean
Rob Lightbown on October 4, 2011, 5:45 am

The global operational and ensemble model guidance continue to strongly hint at the potential for some sort of tropical or even sub-tropical development either in the western Caribbean, the eastern Gulf of Mexico or the Florida Straits & the Bahamas starting this upcoming weekend.

The latest GFS model forecasts that a storm system will form in the central and northwestern Bahamas on Sunday and Monday and forecasts this system to track north-northwestward along the east coast of Florida around the middle part of next week and eventually into South and North Carolina next Thursday or Friday.

The NOGAPS model forecasts the development of a tropical system in the southwestern Caribbean by about Saturday and forecasts this system to track right over Jamaica as a tropical storm on Sunday night or Monday morning. From there, the NOGAPS model forecasts this tropical system to eventually track into the Bahamas by next Tuesday as a tropical storm.

The Canadian model forecasts that this system will start out as a broad low pressure system just southwest of Jamaica on Friday. The Canadian model forecasts that this system will strengthen into a tropical storm along the south coast of Cuba on Saturday night and shows it tracking into the Florida Keys as a tropical storm on Sunday. The longer range Canadian model guidance forecasts that this system will track into the eastern and central Gulf of Mexico once we head into Monday, Tuesday and Wednesday of next week. The Canadian model then forecasts this tropical storm to loop around the Gulf of Mexico and pulls it through the Florida Keys for a second time next Thursday before tracking east-northeast into the northwestern Bahamas next Friday.

The European model forecasts the development of what looks like a sub-tropical storm in the Yucatan Channel on Sunday and forecasts it to track northward into the Florida Big Bend area next Tuesday with tropical storm force winds.

It should be pointed out that the upward motion values of the Madden Julian Oscillation are quite high from October 12 to October 18 and I strongly suspect that with the overall pattern of a strong high pressure system over the Mid-Atlantic and northeastern United States that we will see tropical development starting this weekend somewhere between the Bahamas and the western Caribbean.

I am going to lean a little more towards the ensemble members of the European and GFS models as they are performing pretty well with the consistency of the forecast of a tropical system developing starting this weekend. So, my thinking is that we will see development occur right along that stationary front that extends from the northwestern Bahamas west-southwest to the northwestern Caribbean and the Yucatan Peninsula. I suspect we will see an initially broad area of low pressure form in the western Caribbean on Friday and Saturday that winds up into a tropical storm in either the southeastern Gulf of Mexico or in the Florida Straits by Monday. From there, I think we will see a slow northward moving tropical storm that tracks across the eastern Gulf of Mexico just off of Florida’s west coast on Tuesday and Wednesday of next week.

It is looking likely that strong easterly winds of 25 to 45 mph and heavy rains will affect much of the Florida Peninsula and into Georgia starting on Friday and continuing right through this entire upcoming weekend and into possibly Tuesday and Wednesday of next week. Additionally the strong easterly wind fetch will cause very rough seas, riptides and coastal flooding along the entire Florida coast, both the east coast and the west coast of Florida. One analog that is being used for this potential system is the May, 2009 Gulf of Mexico storm that tracked westward across Florida from the Atlantic. This Gulf storm led to some severe weather and tornadoes across Florida and this is something that could be quite possible (severe weather with a tornado threat) across the Florida Peninsula this weekend.

So, everyone across the Florida Peninsula should be aware of the potential for several days of heavy rainfall, strong winds, coastal flooding, rip tides and severe weather with a tornado potential starting on Friday and continuing right through this upcoming Columbus Day weekend.

[ronjon]

Looks increasingly likely that a sutropical storm will develop this weekend near the FL straits/SE GOM/SE FL. ECM staying consistent with support from many ensemble members. There's going to be lots of upper energy to assist in development of low pressure. HPC's thoughts below. Perhaps someone can pull the storm track analogs that HPC is refering to below.

THE EVOLUTION OF A HYBRID/SUBTROPICAL CYCLONE NEAR FLORIDA REMAINS
SIMILAR TO WHAT WAS EXPECTED THIS TIME YESTERDAY...AS THE 12Z
GLOBAL ENSEMBLE GUIDANCE HAS KEPT GOOD DAY TO DAY CONTINUITY WITH
THE SYSTEM AND STILL SHOWS GOOD SUPPORT FOR ITS EXISTENCE. THIS
LOW IS SPAWNED BY ENERGY FROM THE WESTERLIES WHICH DROPS
SOUTH/SOUTHWEST INTO THE FLORIDA PENINSULA IN A FEW DAYS. A
MOBILE RIDGE TO ITS NORTH AND WEAKNESS TO THE CYCLONES NORTHWEST
CAUSED BY THE PLAINS TROUGH SHOULD LEAD TO A SLOW NORTHWEST
PROGRESSION OF THIS LOW WITH TIME. THE ECMWF/CANADIAN
DETERMINISTIC RUNS HAVE BECOME MORE EMPHATIC WITH ITS DEEPENING
SINCE THIS TIME YESTERDAY...LIKELY DUE TO THE TEPID SEA SURFACE
TEMPERATURES ACROSS THE FLORIDA STRAITS...BUT THEY LIE ON THE WEST
SIDE OF THE 12Z GLOBAL ENSEMBLE SPREAD. GALE-FORCE WINDS AND
ASSOCIATED HEAVY RAINFALL REMAIN IN THE CARDS ACROSS NORTHEAST
FLORIDA/GEORGIA FROM SATURDAY ONWARD. POSSIBLE OCTOBER ANALOGS TO
THIS FEATURE /WHICH SHOWED A SIMILAR PATTERN ACROSS THE WEST AND
HIGH PLAINS/ REMAIN THE OCTOBER 14 1956 QUASI-TROPICAL CYCLONE AND
THE OCTOBER 4 1974 CYCLONE /SUBTROPICAL STORM FOUR/. THE TRACK OF
THIS SYSTEM IS EXPECTED TO LIE NORTHEAST/TO THE RIGHT OF THE MAY
19-20 2009 GULF GALE WHICH CAUSED A LARGE AREA OF OVER SEVEN
INCHES OF RAIN ACROSS NORTHEAST FLORIDA. STAY TUNED.

[AJC3]

Looks increasingly likely that a sutropical storm will develop this weekend near the FL straits/SE GOM/SE FL. ECM staying consistent with support from many ensemble members. There's going to be lots of upper energy to assist in development of low pressure. HPC's thoughts below. Perhaps someone can pull the storm track analogs that HPC is refering to below.

At your service! It's REALLY easy to do. Just go the HPC reanalysis page...

http://www.hpc.ncep.noaa.gov/ncepreanal/

What I did was type in 2-3 days before (CURRENT DATE) and after (END DATE) the analog dates to see the complete evolution of the pattern. Then just press the LOOP button, and voila! You get 200MB, 500MB, 850MB and 1000 MB reanalyses!

Here are the directories for OCT 1956 and 1974

http://www.hpc.ncep.noaa.gov/ncepreanal/data/1956/10/

http://www.hpc.ncep.noaa.gov/ncepreanal/data/1974/10/

[KUEFC]

So what is the chance in % that the models have this wrong? or overhyping it so to speak?

[AJC3]

So what is the chance in % that the models have this wrong? or overhyping it so to speak?

Slim to none. Rest assured, "something" will form - even if it is a weak surface trough it will turn unsettled and very wet from late this week through this weekend, and into early next week.

[KUEFC]

Thanks

[dizzyfish]

Blast it!!! I knew something would make for icky weather this weekend. I'm having an estate sale. CRAP!

I hate to post for self serving info but here goes.

What are my chances of being able to pull off this sale on Saturday (Oct 8th) from 8am - 2pm??? A large portion of the sale has to be outside due to the size of the items. And I have advertised it all over the place too. Argh.

[AJC3]

Blast it!!! I knew something would make for icky weather this weekend. I'm having an estate sale. CRAP!

I hate to post for self serving info but here goes.

What are my chances of being able to pull off this sale on Saturday (Oct 8th) from 8am - 2pm??? A large portion of the sale has to be outside due to the size of the items. And I have advertised it all over the place too. Argh.

Your weather on the west coast isn't going to be nearly as bad as it will be on the east coast on Saturday. Since the flow is going to be offshore in your area, you won't have nearly as high coverage of showers, especially in the morning. You might be able to get 8AM to noon or a little afterwards in with no problem...by the afternoon might be another story as things heat up. Just keep an eye on the radar.

[dizzyfish]

Thank you so much for the info.

[SFLcane]

So what is the chance in % that the models have this wrong? or overhyping it so to speak?

Slim to none. Rest assured, "something" will form - even if it is a weak surface trough it will turn unsettled and very wet from late this week through this weekend, and into early next week.

AJC3 your thinking is VERY different from WFO in miami as per them there isn't going to be much to trigger heavy rainfall later this week.

[jlauderdal]

EXTENDED FORECAST...
THE LONG RANGE MODELS ARE STILL SHOWING THAT THE HIGH OVER THE
TENNESSEE VALLEY WILL MOVE SLOWLY EAST INTO THE MID ATLANTIC
STATES THIS WEEKEND. THE LONG RANGE MODELS ARE ALSO STILL UNCERTAIN
TO ANY DEVELOPMENT OF LOW PRESSURE IN THE REGION OF SOUTH FLORIDA
ALONG THE STATIONARY FRONT OVER THE FLORIDA KEYS. SO WILL CONTINUE
THE NORTHEAST BREEZY TO WINDY CONDITIONS OVER THE CWA THIS
WEEKEND WITH ISOLATED TO SCATTERED SHOWERS FOR MOST OF THE AREA.
THE ONLY EXCEPTION TO THIS IS THAT THE EAST COAST AND THE ATLANTIC
WATERS COULD ALSO SEE A FEW THUNDERSTORMS THIS WEEKEND...DUE TO
THE LITTLE BIT DEEPER MOISTURE IN PLACE.

AT THIS TIME...IT DOES NOT LOOK LIKE A HEAVY RAINFALL EVENT THIS
WEEKEND OVER SOUTH FLORIDA AS THE LONG RANGE MODELS DO NOT SHOW
ANY SYNOPTIC FORCING OVER THE AREA. THE STEERING FLOW WILL ALSO BE
FROM THE NORTHEAST TO EAST AROUND 20 KNOTS WHICH IN TURN WILL
CAUSE ANY SHOWERS OR THUNDERSTORMS THAT DO DEVELOP TO MOVE VERY
QUICKLY ACROSS THE AREA LIMITING THE DURATION OF RAINFALL.
THEREFORE WILL REMOVE THE HEAVY RAINFALL WORDING FROM THE EXTENDED
HWO SECTION.

miami weather office not jumping on models that show area form by south fl

they have been tepid about it for a day now

[AJC3]

So what is the chance in % that the models have this wrong? or overhyping it so to speak?

Slim to none. Rest assured, "something" will form - even if it is a weak surface trough it will turn unsettled and very wet from late this week through this weekend, and into early next week.

AJC3 your thinking is VERY different from WFO in miami as per them there isn't going to be much to trigger heavy rainfall later this week.

Yeah, no trigger for heavy rainfall...except for the large mid-upper level low overhead, deep moisture, strong onshore flow, and a developing surface low. If you go back a page, you'll see why I'm in pretty stark disagreement with them. Granted, my forecast area is north of theirs and the heavier rain may fall farther north across central FL. We'll see how it plays out...I've been wrong before, but this setup is similar to previous heavy rain events in the state.

Here's the HPC manual surface progs for days 3-7.



If that winds up coming remotely close to reality, there will be a lot of heavy rain over the state.

[Frank2]

The GFS shows weak low pressure off the FL and TX coast, but not much more, though as the Pro Mets said at least it'll bring some rain this way for the weekend, and that's good since we are almost at the end of the rainy season down here...

Frank