ATL: INVEST 95L - Discussion

[corpusbreeze2]

There seems to be a nice low level vort in vis loop. This low seems to be moving at a good clip. Could be on the Mexican coast in less than 36 hrs. If the low could slow down some, and give the rest of the storm a chance to stack, we could have us a TS. There is no Manuel in front of this storm hindering movement or development.

[Sanibel]

It needs some time to refire.

[chaser1]

There seems to be a nice low level vort in vis loop. This low seems to be moving at a good clip. Could be on the Mexican coast in less than 36 hrs. If the low could slow down some, and give the rest of the storm a chance to stack, we could have us a TS. There is no Manuel in front of this storm hindering movement or development.

Deep bursting which should soon ensue, and likely continue into this eve's diurnal max should impact its forward motion. As the low level vort becomes once again better aligned with the mid levels, I would think its not unreasonable for 95L to possibly even temporarily stall by late morning. I'd guess it'll be tagged a depression between late tonight and early tomm. a.m.

[TropicalAnalystwx13]

95L is struggling with subsidence across the Bay of Campeche. This and the moderate shear the system is experiencing should subside by Friday which should allow for 95L to become a tropical cyclone if it already isn't by that time.

It's looking more and more likely that this stalls for a bit just off the coastline of Mexico and then it sent northeast, eventually being absorbed into the frontal boundary. Lots of rain but a system of little significance intensity-wise.

[tailgater]

Should start realy firing off soon, TD tomorrow after recon if not before. IMHO.

[Dean4Storms]

Looks like it already has a pretty good lower level circulation, just needs a good burst of convection this could take off pretty quickly.

[Frank P]

Looks like it already has a pretty good lower level circulation, just needs a good burst of convection this could take off pretty quickly.

Well it better slow down because it looks to be heading off at about 280 deg at a pretty good clip as well atm ... my unofficial opinion..

[cycloneye]

Looks like it already has a pretty good lower level circulation, just needs a good burst of convection this could take off pretty quickly.

Well it better slow down because it looks to be heading off at about 280 deg at a pretty good clip as well atm ... my unofficial opinion..

Not moving too fast. From 18z data.

305DEG SPDCUR = 9KT

[GCANE]

The upper atmospheric PV anomaly has dissipated quite a bit since this morning.

Might have something to seriously talk about around sunrise.

[Frank P]

Looks like it already has a pretty good lower level circulation, just needs a good burst of convection this could take off pretty quickly.

Well it better slow down because it looks to be heading off at about 280 deg at a pretty good clip as well atm ... my unofficial opinion..

Not moving too fast. From 18z data.

305DEG SPDCUR = 9KT

thanks, sure looks faster than that on sat loops... must be an illusion to these old eyes..

[Aric Dunn]

Convection building to the center and can be seen on radar too.
http://www.ssd.noaa.gov/PS/TROP/floater ... -long.html


http://smn.cna.gob.mx/radares/sabancuy/ ... _anima.php

[Riptide]

Looks to be a little on the sub-tropical side; or perhaps engulfed by dry air.

[TJRE]

Mid -Level Shear 1800UTC

sure wont help him improve

http://tropic.ssec.wisc.edu/
[/URL]

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RMTC - Sector 5 - Ch 3 - Water Vapor
http://rammb.cira.colostate.edu/ramsdis/online/rmtc.asp#Sector%205



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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.

[cycloneye]

From Tampa afternoon AFD:

.LONG TERM (SATURDAY THROUGH TUESDAY)...
THE LONG TERM FORECAST PERIOD BEGINS WITH AN APPROACHING FRONTAL
SYSTEM. THE FRONT IS ASSOCIATED WITH A LOW PRESSURE SYSTEM CENTERED
NORTH OF THE GREAT LAKES IN ONTARIO. MOST GUIDANCE CONTINUE IN
AGREEMENT INTO MONDAY WITH THE FRONTAL BOUNDARY WEAKENING AS IT
ENTERS FLORIDA FROM GEORGIA AND ALABAMA LATE ON SUNDAY INTO MONDAY
MORNING. EXPECT THE MOIST TROPICAL AIRMASS TO PROVIDE PLENTY OF
OPPORTUNITY FOR CONVECTION DURING THE WEEKEND...THOUGH THE SHIFT
IN WINDS FROM THE EAST TO THE SOUTH MAY CAUSE SHOWER/THUNDERSTORM
TIMING TO BEGIN EARLIER IN THE DAY AND STICK AROUND LONGER INTO
THE OVERNIGHTS THAN IT HAS BEEN IN THE EASTERLY PATTERN.

THE GFS AND ECMWF ARE BOTH TRYING TO FORM A LOW PRESSURE SYSTEM
ALONG THE FRONT IN THE GULF LATE MONDAY INTO TUESDAY. BOTH ALSO
MAINTAIN A LARGE AMOUNT OF GULF MOISTURE OVER THE SUNSHINE STATE.
EXPECTING THERE TO BE AN INCREASE IN HEAVY RAIN CHANCES TO START
THE WORK WEEK. CONFIDENCE ON THE DEVELOPMENT AND PROGRESSION OF
ANY POTENTIAL SYSTEMS IS LOW AND THIS FORECAST CHALLENGE BEARS
MONITORING OVER THE NEXT FEW DAYS TO SEE IF THE MODEL GUIDANCE
BEGINS TO BUILD A TREND.

RIP CURRENT RISK TO INCREASE LATE SATURDAY THROUGH SUNDAY AND INTO
EARLY NEXT WEEK AS INCREASING SW SEAS BREAK ALONG AREA BEACHES.

WITH THE FRONT WEAKENING BEFORE REACHING WEST CENTRAL AND SOUTHWEST
FLORIDA...FORECAST TEMPERATURES WILL BE CLOSE TO CLIMATOLOGICAL
NORMALS FOR THIS TIME OF YEAR. POPS WERE RAISED TO ACCOUNT FOR THE
MOIST TROPICAL AIRMASS...THOUGH GUIDANCE IS TRENDING HIGHER WITH
PRECIPITATION FORECASTS IN THE EXTENDED FOR NEXT WEEK. WPC CONTINUES
TO OFFER RAINFALL FORECASTS OF 3 TO 5 INCHES OVER MUCH OF THE AREA
OVER THE NEXT 7 DAYS. IF ANYTHING...THE UNCERTAINTY IN THE EXTENDED
DUE TO POTENTIAL SYSTEM DEVELOPMENT SHOULD BE A REMINDER THAT
HURRICANE SEASON IS NOT YET OVER AND THAT A SECOND PEAK IN ACTIVITY
TYPICALLY OCCURS IN OCTOBER.

[Stormcenter]

Lots of unknowns based on this discussion from the NWS out of New Orleans, LA.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
335 PM CDT WED SEP 18 2013

LONG TERM...
THE GENERAL PATTERN HAS NOT CHANGED VERY MUCH FROM THE PREVIOUS
FORECAST. WEAK UPPER LEVEL RIDGE IS CURRENTLY IN PLACE ACROSS THE
GULF COAST. ABUNDANT MOISTURE OVER THE GULF OF MEXICO IS GRADUALLY
WORKING ITS WAY INTO THE CWA. THE SOUTHERN EDGE OF THE HIGH WILL
CONTINUE TO BE FAIRLY WEAK WHICH WILL ALLOW FOR EVEN MORE MOISTURE
TO MOVE INTO THE AREA AND THUS RAIN CHANCES WILL BE COMING UP ON
THURSDAY. NOW HAVE 40 PERCENT COVERAGE FOR LOCATIONS ALONG AND SOUTH
OF A BATON ROUGE TO NEW ORLEANS LINE.

AN UPPER TROUGH IS STILL EXPECTED TO SWING ACROSS NORTHERN SECTIONS
OF THE COUNTRY AND DIG ALL THE WAY TO THE LOWER MISSISSIPPI VALLEY
BY SATURDAY. TROPICAL MOISTURE WILL GET DRAWN NORTHWARD TOWARDS THE
APPROACHING FRONTAL BOUNDARY. THIS WILL BRING PRECIP WATER VALUES UP
TO NEARLY 2.5 INCHES. MODELS CONTINUE TO SUGGEST A LARGE SWATH OF
SHOWERS AND THUNDERSTORMS WILL PASS ACROSS THE FORECAST AREA FRIDAY
AND SATURDAY. SO HAVE DECIDED TO AGGRESSIVELY INCREASE RAIN CHANCES
TO LIKELY AND DEFINITE CATEGORIES. THROUGH THE PERIOD...2 TO 3
INCHES OF RAIN WILL BE POSSIBLE WITH LOCALLY HIGHER AMOUNTS.

MODEL DISAGREEMENT CONTINUES TO EXIST ON WHEN THE BULK OF RAIN WILL
BE PUSHED OUT BY THE COLD FRONT. ECMWF SUGGESTS THAT AN UPPER LOW
WILL CLOSE OFF AT THE BASE OF THE TROUGH OVER THE GULF SOUTH WHICH
WILL CAUSE THE FRONT TO SLOW DOWN AND NOT MOVE THROUGH UNTIL LATER
ON SUNDAY. GFS ON THE OTHER HAND IS MUCH MORE PROGRESSIVE WITH THE
FRONT AND ABOUT 12 HOURS FASTER. FOR NOW HAVE KEPT LOW END RAIN
CHANCES ON SUNDAY WHICH IS MORE THAN GFS AND LESS THAN ECMWF. NOT
TO FORGET TEMPERATURES...HAVE DROPPED FORECAST HIGHS BY A A DEGREE
OR 2 ON FRIDAY AND SATURDAY. EXPECTING OVERCAST CONDITIONS AND QUITE
A BIT OF RAIN COVERAGE WHICH MEANS TEMPERATURES SHOULD NOT BE
REACHING MORE THAN MID 80S...IF THAT.

MODELS HAVE ALSO STARTING HINTING AT SOME FORM OF CYCLOGENESIS ALONG
THE FRONTAL BOUNDARY AS IT REACHES THE COAST. BOTH THE ECMWF AND GFS
LATEST RUNS INDICATE A BAROCLINIC SURFACE LOW DEVELOPING OVER THE
GULF OF MEXICO AND TRACKING NORTHEASTWARD AS THE FRONT EXISTS THE
REGION. WHILE THIS IS OCCURRING...AREA OF LOW PRESSURE THATS MOVING
ACROSS THE YUCATAN WOULD JUST SIT AND MEANDER IN THE BAY OF CAMPECHE
TO SOUTHWEST GULF THROUGH MID WEEK. STILL QUITE A BIT OF UNCERTAINTY
IF THIS SOLUTION OR SOME FROM OF IT WILL OCCUR. FOR NOW JUST
SOMETHING TO KEEP AN EYE ON AS CURRENTLY STILL CLOSE TO THE PEAK OF
HURRICANE SEASON.

[TJRE]

http://www.nhc.noaa.gov/marine/

TAFB 72 hr cast
take note of the eastward-- arrow projection



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HPC keeps it out in the Gulf thru day 7
http://www.hpc.ncep.noaa.gov/medr/nav_conus_pmsl.php?fday=4&fcolor=wbg



http://www.hpc.ncep.noaa.gov/medr/medr.shtml

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[rockyman]

The low level vorticity (over water) seems to be slowing down and "waiting" for the mid-level vorticity (over the Yucatan) to catch up. I'll be watching the NW tip of the Yucatan tonight to see if the system can stack itself.


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.

[ROCK]

the east arrow is due to the front....the HPC has it missing the front on the backside obviously as does the NO NWS....so it just hangs out in the GOM. Some models have been hinting at this as well as a low along the front. Might be watching this into next week....lol

[ozonepete]

Mid -Level Shear 1800UTC

sure wont help him improve

http://tropic.ssec.wisc.edu/
[/URL]

It's hard to see under all of those white contour lines but the mid-level shear on that chart is 5 to 10 knots (color code for mid-level shear is on the right side and is different from the color code for overall shear). That's low shear and not inhibiting for development at all.

[Hammy]

The circulation looks more organized on radar than on satellite, so is it possible that it is a bit elongated on the western side and could developed more tightly closer to the convectio?