cieldumort
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Pre-Season Invest 94L
It is perhaps noteworthy that we are not yet even in June and are now following the fifth Invest of the year, and third just this month.
A persistent trough of low pressure in the northwestern Caribbean has been bubbling up some convection for the past few days and is now being tracked as Invest 94L. 94L really seems to consist of two or three weak lower level circulations (noted by the red "X"s I have placed on the image above) associated with a broad, elongated trough in the region.
Upper level winds are currently less than favorable for any significant development, but may become less unfavorable over the next few days.
Whether or not 94L ever develops into a tropical cyclone, this feature is currently forecast to fester, and only slowly make its way across Cuba, and possibly ultimately across south Florida, as well. In any event, 94L is in a region of steering currents that will likely continue to toss several days of showers and storms to its northeast, whatever may come, and it appears that more of these rains have the potential to become frequent, and heavy.
Given that 94L is land-locked with forecast steering currents that only slowly move it along, it is one to watch, primarily because of its potential for producing excessive rainfalls and resultant flooding.
Extreme south Florida is already under a Flood Watch for the rains which have occurred so far. The total at Miami International Airport was already 9.7" as of 10:00PM on the 22cd.
4:30AM EDT Edit: Added 0645 UTC IR Image
As can be seen in the image above, almost all of the deep convection associated with the surface trough is displaced well to its east tonight.
Added: Invest 94L upgraded to Subtropical Storm Beryl on 05/25/2012 at 11:00PM EDT
Added: Subtropical Storm Upgraded to Tropical Storm Beryl on 05/27/2012 at 2:00PM EDT
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danielw
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I've been watching 94L for a few hours now. It really has no discernible features other than 2 or 3 areas of heavy thunderstorms.
One of the reporting stations, MUCL, on the southern Coast of Cuba reported near tropical storm force winds for about 3 hours earlier this evening. (See below)
The pressures are generally above 1009mb and most of the other reporting stations in the NW Caribbean have winds under 20 mph.
MUCL 230705Z AUTO 11017KT 25/23 Q1009
MUCL 230605Z AUTO 11023KT 25/23 Q1010
MUCL 230505Z AUTO 11023KT 25/23 Q1010
MUCL 230405Z AUTO 11026KT 25/23 Q1009
MUCL 230305Z AUTO 12028KT 25/23 Q1010
MUCL 230205Z AUTO 11030KT 25/23 Q1009
MUCL 230105Z AUTO 12025G37KT 25/22 Q1009
MUCL 230005Z AUTO 12025KT 25/22 Q1009
A few of the models suggest the system will slowly move across the Florida Straits and the Bahamas through Friday. Reach a point just offshore of the Jacksonville/ Savannah area and then retrograde back to the west for the weekend.
The model runs that I have looked at keep the system below Tropical Storm strength. Other than the possibility of more rain along the Florida Peninsula it appears that 94L will be a rainmaker for the Memorial Day Weekend.
Drive Safe.
**Note: The HWRF now takes the system to North Carolina. Possibly as a weak Tropical Storm, based on wind speeds. The system then bounces back and forth along the N.C. and S.C. beaches.
http://moe.met.fsu.edu/tcgengifs/
http://www.tropicalatlantic.com/models/d...;latestinvest=1
Edited by danielw (Wed May 23 2012 04:25 AM)
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cieldumort
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Looking at the HWRF, it already appears too eager to grow 94L, which is really still not all that much more than a surface trough with some eddies along it. If the HWRF had its way, we would already be seeing a coalescing about a closed low of some significance, which just is not happening. Shear is still high, and with lots of dry air pushing through the GOM, this is giving 94L a double dose of challenges in the near term.
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cieldumort
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The low level center of 94L is crossing right over extreme south Florida as this entry (May 24, 2012 - 1PM EDT).
The structure of 94L has been gradually improving since last night, and it is now fair to say that a primary center has taken shape, currently in the approximate location of 25.5N 81W, heading north-northeast.
With the center passing to the west of Station MLRF1 in Molasses Reef, FL (location 25.012 N 80.376 W), 94L produced a peak 10-minute average wind speed of about 27 knots (31 MPH), with a peak gust of about 31 knots (36 MPH), at an elevation of 47 feet (only about 17 feet above the standard for measuring surface winds).
MLRF1
NHC has just increased 94L's odds of becoming an officiated subtropical or tropical cyclone to 40% within the next 48 hours, and this could be conservative.
Due to shear, convection remains displaced to the east of the center, with the most vigorous convection presently occurring in its northeastern quadrant.
Invest 94L at 1702 UTC
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cieldumort
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Invest 94L has been organizing briskly over the past couple of hours, and it is becoming increasingly likely that may be inclined to pull the trigger for a Tropical Storm Beryl sooner, rather than later.
As of 2:45PM EDT, 94L is now producing sustained winds of tropical storm force at the surface within its approximate center. Pressures continue falling, and data so far suggest that the minimum pressure inside 94L may already be down to around 1003mb.
Member ftlaudbob brought to my attention that winds where he is are now max sustained at around 25MPH, gusting over 50, and that the local Miami forecast office has issued a High Wind Warning for coastal Miami-Dade and Broward counties, effective until 6PM this evening.
Verifying this report and warning, within just the past few hours Station VAKF1 - 8723214 at Virginia Key, FL, measuring from an elevation of only 10 meters above site level, has been blasted by sustained tropical storm force winds, with gusts over 55MPH.
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MichaelA
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Looking at the latest RGB Sat loop, it appears that the LLC has dissipated. If the shear relaxes as forecast there could be reformation of a low level circulation.
-------------------- Michael
PWS
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Ed Dunham
Former Meteorologist & CFHC Forum Moderator (Ed Passed Away on May 14, 2017)
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Its still there, but quite weak - around 25.4N 80.0W - its been drifting to the east for about the last 4 hours. The southwesterly shear did shove a lot of the convection to the northeast of the center. 's 40% was actually based on weakening tonight and then redeveloping on Friday - just have to see if it gets motivated by the Gulf Stream. Lots of dry air in the Gulf but it could get slowly modified. The southwesterly upper shear is expected to weaken by Saturday - just not sure yet if there will be enough left of 94L to regenerate by then.
ED
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ftlaudbob
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now gives 94L a 60% chance of becoming a cyclone within 48 hours.We could have our 2nd named storm before the season has even started.
--------------------
Survived: 10 hurricanes in Rhode Island,Florida and the Yucatan of Mexico .
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danielw
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These reports are from earlier today in the Miami NWS Forecast area. I suspect some of the wind speeds are due to the pressure gradient.
1254 PM NON-TSTM WND GST 4 SE DOWNTOWN MIAMI 25.73N 80.16W
05/24/2012 M58.00 MPH AMZ630 FL MESONET
PEAK WIND GUST OF 50 KT...58 MPH...AT VIRGINIA KEY NOS
SITE. SUSTAINED WIND 39 KT AT 1254 PM EDT WITH SUSTAINED
WINDS OF 34 KT OR GREATER OBSERVED FROM 1254 PM TO 118 PM
EDT.
1255 PM NON-TSTM WND GST N KEY BISCAYNE 25.69N 80.16W
05/24/2012 M62.00 MPH MIAMI-DADE FL MESONET
PEAK GUST OF 54 KT...62 MPH...AT WX FLOW SITE ON KEY
BISCAYNE. SUSTAINED WIND 33 KT...38 MPH.
1255 PM NON-TSTM WND GST NORTH MIAMI 25.89N 80.18W
05/24/2012 M46.00 MPH MIAMI-DADE FL MESONET
PEAK WIND GUST OF 40 KT...46 MPH...AT WEATHER FLOW SITE
XNMI IN NORTH MIAMI.
0100 PM NON-TSTM WND GST 4 ESE CORAL GABLES 25.71N 80.21W
05/24/2012 M50.00 MPH AMZ630 FL MESONET
PEAK WIND GUST OF 43 KT...50 MPH...AT WEATHER FLOW SITE
DINNER KEY LIGHT ON BISCAYNE BAY. SUSTAINED WIND OF 34
KT...39 MPH AT THIS TIME.
0100 PM NON-TSTM WND GST 3 SW KEY BISCAYNE 25.66N 80.19W
05/24/2012 M58.00 MPH AMZ630 FL MESONET
PEAK WIND GUST OF 50 KT...58 MPH...AT WX FLOW SITE
BISCAYNE BAY LIGHT 20. SUSTAINED WINDS OF 34 KT...39
MPH...OR GREATER FROM 1235 PM EDT TO 130 PM EDT.
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papaswamp
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Latest:
SPECIAL TROPICAL WEATHER OUTLOOK
NWS National Hurricane Center MIAMI FL
255 PM EDT FRI MAY 25 2012
FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...
1. A BROAD AREA OF LOW PRESSURE...CENTERED ABOUT 275 MILES SOUTHEAST OF
THE COAST OF THE CAROLINAS...IS PRODUCING WINDS TO GALE FORCE
MAINLY TO THE NORTHEAST AND SOUTHEAST OF THE CENTER. THE LOW HAS
BECOME A LITTLE BETTER DEFINED THIS AFTERNOON...ALTHOUGH THE
ASSOCIATED SHOWER AND THUNDERSTORM ACTIVITY REMAINS POORLY
ORGANIZED DUE TO STRONG UPPER-LEVEL WINDS. ENVIRONMENTAL
CONDITIONS ARE EXPECTED TO BECOME MORE CONDUCIVE FOR DEVELOPMENT ON
SATURDAY OR SUNDAY...AND THIS SYSTEM HAS A HIGH CHANCE...80
PERCENT...OF BECOMING A TROPICAL OR SUBTROPICAL CYCLONE DURING THE
NEXT 48 HOURS. LITTLE MOTION IS EXPECTED TODAY...BUT A
WEST-SOUTHWESTWARD OR SOUTHWESTWARD MOTION SHOULD BEGIN TOMORROW
AND CONTINUE THROUGH SUNDAY. COASTAL INTERESTS FROM THE CAROLINAS
SOUTHWARD THROUGH NORTHEASTERN FLORIDA SHOULD MONITOR THE PROGRESS
OF THIS SYSTEM OVER THE MEMORIAL DAY WEEKEND. IN ADDITION...LOCALLY
HEAVY RAINFALL...FLOODING...AND GUSTY WINDS WILL CONTINUE TODAY
OVER PORTIONS OF CENTRAL CUBA AND THE BAHAMAS. ANOTHER SPECIAL
TROPICAL WEATHER OUTLOOK WILL BE ISSUED TOMORROW...OR EARLIER IF
NECESSARY. FOR ADDITIONAL INFORMATION ON THIS SYSTEM...PLEASE SEE
HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...AND
PRODUCTS FROM YOUR LOCAL WEATHER OFFICE.
ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
$$
FORECASTER FRANKLIN
NNNN
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cieldumort
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Beryl is likely to be named by Saturday morning. As can be made out in the deep penetrating microwave image above, 94L has acquired sufficient framework of a tropical cyclone, and now with deep convection starting to wrap around from top downward, it is almost certainly just a matter of time, and most likely just a little time, before advisories are initiated on (initially marginally) tropical storm Beryl - possibly listed as a sub-tropical storm to start, however.
Advisories will probably begin with Beryl at a minimum of 40 knots, by Saturday morning.
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danielw
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NHC Advisory is to be issued shortly. I'm not sure if they will go with TS Beryl or STS Beryl.
Waiting for the Advisory
Note that the latest advisories are always available as drop-down items on the Main Page.
Edited by Ed Dunham (Sat May 26 2012 12:27 AM)
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CoconutCandy
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Sub-Tropical Storm Beryl appears to be assuming more tropical-like characteristics today.
As compared to yesterday, STS Beryl is looking much more "tropical like", with deep convection now initiating very near the low level center of circulation, as shown on both animated satellite loops and, more recently, on Long Range Doppler Radar from Newport / Morehead, North Carolina.
This is in contrast with yesterday's visible satellite signature, which portrayed a comma shaped band of convection well displaced from the center of the storm, a classic characteristic feature of SUB - tropical systems.
Passive Microwave Imagery from polar orbiting satellites also reveals a much more "storm like" presentation, with the deepest convective activity appearing in more 'traditional' concentric rings about the storm's center.
...
Edited by CoconutCandy (Sat May 26 2012 01:33 PM)
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Fairhopian
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Given Beryl's more tropical characteristics, the low-level COC is a little easier to detect, and for the past hour or two, the visible satellite seems to suggest Beryl's movement is more SSW than SW, or maybe the COC has shifted south of the forecast track. If more convection continues to closely wrap, that should either solidify or dispel the apparent COC position being more south at present.
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MichaelA
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It seems they are expecting Beryl will acquire full tropical status sometime tomorrow, if not later this evening. Convection is trying to wrap around the surface center this afternoon. If it can overcome all that dry air, we'll have a fully tropical system.
Whatever else happens this season, 2012 will already be in the record books with two named storms forming before the official start of the season.
-------------------- Michael
PWS
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GlenJohnson
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Strikes me as odd we've had two storms forming,but forming off the coast of North Florida even before the start of the Hurricane season. A bit of foreboding there. Time to fill up the lakes?
Edited by GlenJohnson (Sat May 26 2012 09:06 PM)
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k___g
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It does appear that Beryl is becoming better organized but should not be a major concern. Any rain we can get from her will be wonderful.
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Ed Dunham
Former Meteorologist & CFHC Forum Moderator (Ed Passed Away on May 14, 2017)
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Subtropical Storm Beryl located near 30.7N 77.4W at 27/04Z continuing to move toward the southwest however motion likely to become more west southwesterly in a few hours as blocking high pressure to the north begins to slide eastward and weaken. Sporadic convection continues to fire closer to the center as slow transition to a tropical system occurs overnight into Sunday afternoon.
Beryl has displayed hints of that slow transition throughout Saturday afternoon and evening. Cloud pattern transitions within and near the center of low pressure suggest subtle changes in the upper environment over Beryl. As Beryl crosses the Gulf Stream on Sunday a boost in convection near the center seems likely, however, with cooler shelf water at the coast, intensity will probably not change much since the period of time that the cyclone will have in a fully tropical state will be quite limited before landfall occurs late Sunday evening.
Earlier Saturday afternoon/evening the weak subsidence zone on the west side of the cyclone displayed a greater component of southwesterly motion with little movement toward the west. Although minor, this southwesterly surge could put the eventual landfall location a little further south toward the St. Augustine area. Beryl is expected to weaken at landfall as it spends a day inland - just how far inland will depend on how quickly the high to the north weakens and shifts eastward. A trough approaching from the central U.S. should move Beryl back into the Atlantic and off to the northeast away from land.
Sustained tropical storm force winds are likely to be confined to a relatively small area near the center - probably within 60 miles. Rip currents are already a serious problem with this system and this hazard will continue into early next week along the coast from central Florida to the Carolinas.
From : "THE TROPICAL STORM WATCH FOR THE SOUTH CAROLINA COAST NORTH OF
EDISTO BEACH HAS BEEN DISCONTINUED."
ED
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