GOM: INVEST 90L

[gatorcane]

wow a TWO, nice its not even hurricane season yet. I say move the Atlantic season to May 15th along with the EPAC as it seems to be a recurring thing now...

[Ivanhater]

Once again the 18z Nam develops the low in the Gulf in just 12 hours

[Derek Ortt]

keep in mind we went 26 years between May storms before 2007

a better case can be made, however, to extend the season to December 31

[Ivanhater]

Double lows by 30 hours

[cpdaman]

not sure what to make of this low.........considering it has a less than 30% chance of becoming a tropical storm in two days.....(as of now) but also wanted to let people know there is a Low pressure in the gulf now around 25/85 on this loop

http://www.ssd.noaa.gov/goes/east/gmex/loop-vis.html

i mention it here just because it seems nobody really knows which low may become the "dominant" one and i imagine everyone will be on this thread.......since the non-tropical low may not get named a invest....(unless it's determined to be sub-tropical later)

[gatorcane]

18Z NAM develops two lows one near the FL Keys and another just offshore the SE coast of Southern FL -- if that verifies, I can only imagine the rain event that is about ready to unfold.

Also, Radar from NWS shows extremely heavy rain moving into Central Palm Beach County...perhaps spreading to the Western suburbs of metro Palm Beach, Broward, and Miami-Dade in a few hours.

[MiamiensisWx]

The following post is NOT an official prognosis.

A complex forecast is evolving today. Currently, a stationary front extends roughly from Melbourne, Florida (MLB), to Sarasota County. The upper level trough is slowly "cutting off" from the departing longwave over the eastern United States. The greatest vorticity advection associated with the base of the trough is occurring off the Big Bend of Florida (south of Apalachicola); therefore, as of 19Z, the best 500-850 mb vorticity is situated over the eastern and southern Bahamas. However, the greatest negative height deviations (per SPC mesoanalysis) are occurring immediately west of the Sarasota-Tampa area. Furthermore, the 12Z GFS suggested that the greatest 500 mb vorticity would have been located east of the Bahamas at this time. However, the preceding data indicate that the greatest vorticity is occurring farther west. As the upper low deepens and retrogrades over the next 24 hours, the low/mid level vorticity will shift closer to Florida. In fact, recent CIMSS data suggest the trend is starting to occur. Additionally, the 12Z GFS projected a slightly greater negative tilt with the departing upper level system over the Northeast; in reality, the current data indicates a more positive tilt. This information indicates that the trough is departing more rapidly, and the mid level ridge will be stronger in the wake of the trough. Overall, it supports the supposition that the upper low will "cut off" farther south/west in the eastern Gulf of Mexico, and it will retrograde more substantially. This evolution is supported by the ECMWF and NAM. Since the surface low will develop more slowly over the Bahamas than the GFS's original projections, it is probable that the main low will consolidate closer to the ECMWF solution; thus, my original support for the GFS solution, in light of the lower baroclinicity east of central FL, appears to be incorrect. A track over southernmost FL (immediately south of a Fort Lauderdale-Bonita Springs line) appears to be more reasonable. I think that the track may be slightly farther north than the ECMWF (and significantly farther north than the NAM), but it will be significantly farther south than the GFS. I also agree with the assessments that suggest greater organization will not commence until tomorrow; the surface pressure center will not become more co-located with the mid/upper level features prior to 24-36 hours. It appears that the primary surface low wiill develop over extreme southern FL and enter the Gulf of Mrxico.

Based on the possible track and synoptic/thermodynamic set-up, a substantial and prolonged period of significant precipitation will affect central/southern Florida. Since baroclinicity will be less prevalent, the stage is set for deep, widespread penetration of tropical moisture across southern FL. Based on the projected position of the upper low, stationary front, and weak surface low, the greatest convergence will likely affect the southeastern mainland of Florida. This trend would be beneficial, since it would also enable extensive precipitation across the Lake Okeechobee region. The exact precipitation totals will be influenced by the position of the mid/upper level features and the surface low. Since I suspect that the surface low will be slightly north of the ECMWF, the best lift and convergence may be focused slightly farther north over SE FL and the interior. However, the entire region will receive extensive precipitation.

As an aside, the environment over southern Florida will be conducive for isolated tornadoes. Note that local directional shear, 0-1 km storm relative helicity (SRH), and boundary layer convergence will be maximized within an environment of increasing mid level divergence. Lifting will be substantial along/south of the stationary front. As the cutoff low develops, mid level wind vectors will increase over the southern FL peninsula. Favorable intrusions of mid level dryness in association with the upper low will also be present. Convective outflow boundaries will also facilitate the threat for short lived, isolated tornadoes. These factors will intersect a warm, moist, and conditionally unstable region.

Edit: The new 18Z NAM has shifted closer to the ECMWF; thus, it is much more reasonable (and closer to my suggested track).

[cycloneye]

West Winds in Cayman islands

Circulation going to the surface?

Code: Select all

 
Latest 4 PM (20) May 18 86 (30) 73 (23) 29.83 (1010) W 8 
 3 PM (19) May 18 86 (30) 73 (23) 29.83 (1010) WNW 7 showers in the vicinity


http://weather.noaa.gov/weather/current/MWCR.html

[x-y-no]

Bring the rain, please!

This weekend's showers were nice, but we could really use a good soaking.

[Ivanhater]

Gulf low takes over

[Rainband]

http://www.ssd.noaa.gov/goes/east/watl/loop-rb.html Look at the animation and highlight fronts, the only low is in the GOM 1010mb????

[Ivanhater]

Looks like what is now 90L, according to most models now, washes out as the Gulf low takes over...

[AdamFirst]

Good slow soaking rain here in Saint Lucie County. That seems to be what to expect over the next few days.

Western Palm Beach and Broward Counties, along with Lake O, are getting hammered by heavy slow moving downpours. Giving the everglades a big gulp and douses the wildfires.

[MiamiensisWx]

There appears to be a broad, ill defined low level surface circulation near 22.5 N 76.5 W:

http://www.ssd.noaa.gov/goes/flt/t1/flash-vis.html

Note that this location is supported by low level vorticity data, and it is considerably farther west than the GFS's projected location for the primary surface low. Based on the pattern, it supports the ECMWF and NAM.

[Aric Dunn]

speaking of rain....

check out the doppler estimates so far in the last 15 hours or ..

the arrow pointing at 8 inches of rain in north central florida with a wide area receiving 6 inches .. thats alot of rain and here im on the edge of that with about 4 inches here in daytona and the streams are already topped off.
anymore rain and things are going to get a little tricky.. problem is there is no end insight .. still raining pretty hard here and with the forecast calling for a lot more rain we may see some significant flooding...also although we have been in a drought fay filled out water table so it will not take much to cause some serious flooding again ..

[Rainband]

There appears to be a broad, ill defined low level surface circulation near 22.5 N 76.5 W:

http://www.ssd.noaa.gov/goes/flt/t1/flash-vis.html

look in the GOM that's the area to watch

[srainhoutx]

Again Key West offers a good disco concerning 90L...snipet...

IT APPEARS THAT SOME FORM OF LOW PRESSURE AREA WILL DEVELOP VERY NEAR
THE KEYS TONIGHT AND TUESDAY BENEATH A LARGE AND DEEP COLD-CORE
CYCLONIC GYRE THAT WILL BE EVOLVING OVER THE EASTERN GULF BASIN. IT
IS LIKELY THAT EPISODES OF STRONGER ASCENT AND DESTABILIZATION
COMBINED WITH SWIRLING DEEP MOISTURE PLUMES WILL INITIATE PLENTY OF
CLOUD COVER AND SHOWERS. LIMITING FACTORS FOR RAIN INCLUDE A LACK OF
LOW-LEVEL FORCING AND SWIRLING DEEP DRY PLUMES. WE WILL KEEP HIGHEST
RAIN CHANCES TONIGHT AND TUESDAY...WITH GRADUALLY DIMINISHING RAIN
CHANCES THEREAFTER IN ASSOCIATION WITH THE CYCLONIC GYRE/SURFACE LOW
GRADUALLY PULLING AWAY TO THE NORTHWEST. A SOUTHERLY WIND FLOW REGIME
WILL DEVELOP AROUND MID WEEK AND THEN LIKELY PERSIST THROUGH THE
UPCOMING HOLIDAY WEEKEND. HOWEVER...DRIER LOW/MID-LEVEL AIR AND A
LACK OF FORCING FOR ASCENT SHOULD LIMIT RAIN CHANCES TO SLIGHT
CHANCE.
http://www.srh.noaa.gov/productview.php ... KEY&max=51

[ronjon]

Low pressure recently developed near 25.3N-84.5W (1010 mb) - just SE of the cutoff ULL - I'm going to focus on this one as both the 18Z NAM and ECM develop a vertically stacked low (at 850 and 500 mb) in the SE GOM.

http://www.ssd.noaa.gov/goes/east/gmex/loop-vis.html

[Evil Jeremy]

As long as this brings rain to South Florida, thats all I care about at the moment with this. I doubt this will form, and if it does, it shouldn't become anything other than a moderate tropical storm.

[Rainband]

Low pressure recently developed near 25.3N-84.5W (1010 mb) - just SE of the cutoff ULL - I'm going to focus on this one as both the 18Z NAM and ECM develop a vertically stacked low (at 850 and 500 mb) in the SE GOM.

http://www.ssd.noaa.gov/goes/east/gmex/loop-vis.html

I agree I posted that above. I knew there was something brewing down there, I have been in pain all day