INVEST 90L: Gulf of Mexico : Gone from NRL

[skysummit]

06z GFS @ 30 Hours

[skysummit]

06z GFS @ 42 Hours...looks like it's falling apart under unfavorable upper conditions.

[skysummit]

06z GFS @ 54 Hours
200mb Plots...30 - 40kt southwesterly shear.

[skysummit]

06z GFS @ 66 Hours...near southwest Louisiana, but dissipated under high shear.

[vaffie]

Interesting Houston discussion. Apparently the front might not make it into SE Texas now. This will most assuredly affect the path of 90L--possibly sending it further south with a building ridge. It's sort of a tossup--it might now sort of stall in the western Gulf a little or even head southwestward--like the latest Canadian model is showing. We'll just have to wait and see.

THAT BEING THE CASE...A WARM AND DRY PERIOD WILL OCCUR THROUGH
THURSDAY. THE MODELS THEN MOVE A SURFACE LOW TOWARD THE TX OR LA
COASTS...ALTHOUGH IT REMAINS TO BE SEEN WHETHER IT WILL BE
SUBTROPICAL OR SUBTROPICAL. ONE MODEL EVEN WEAKENS THE LOW OVER
THE GULF. FOR NOW DECIDED TO PUNT AND GO WITH A WAIT AND SEE
FORECAST BY NOT PUTTING THE LOW IN THE FORECAST GRID FIELD. IN
THE POP AND WEATHER FIELD WENT WITH THE INTERSITE CONSENSUS AND
BROUGHT RAIN CHANCES IN BEGINNING FRIDAY. OVER THE WEEKEND THE
UNCERTAINTY RISES MORE SO BUT FELT CONFIDENT ENOUGH TO LOWER THE
RAIN CHANCES EARLY NEXT WEEK BEGINNING ON SUNDAY. THE ADVERTIZED
COLD FRONT NOW LOOKS TO STAY NORTH OF THE AREA AS BOTH THE GFS AND
ECMWF BUILD A MID LEVEL RIDGE OVERHEAD. THE ENSEMBLE GFS HAS A
WIDE RANGE OF TEMPERATURE VALUES INDICATING SOME MEMBERS ARE GOING
WITH THE FRONTAL PASSAGE AND OTHERS ARE STAYING NORTH. DECIDED TO
SWITCH COURSE ON SUNDAY AND KEEP THE FRONT TO THE NORTH WITH THE
FEELING THAT ANOTHER SURFACE LOW MAY MOVE ACROSS THE GULF.
HOWEVER...DID LOWER THE TEMPERATURES A FEW DEGREES MONDAY MORE
TOWARD THE LATEST ENSEMBLE MEAN MOS GUIDANCE. AM LOOKING FORWARD
TO A BIT MORE RUN TO RUN CONSISTENCY IN THE COMPUTER MODELS
(HOWEVER...IT IS THAT TIME OF YEAR AGAIN).

[wxman57]

Lowest pressure is now near Key West, moving into the eastern Gulf (1006mb). Pressures east of the Bahamas are around 1013-1015mb in those squalls. GFS still looks pretty good, taking a weak low inland into Louisiana Thursday (just 60 hours from now). That's not a lot of time. Winds north of the weak low are dropping this morning as cold air advection decreased. Still, air with dew points in the low 60s or upper 50s is flowing out into the NE Gulf into the low. Chances of this low becoming tropical are about zero. Could it be an STD? That depends on what the NHC criteria are. I haven't seen any consistency in what they designate a TD, so who knows what qualifies for an STD? It's a low with 25 kt winds now, but most of those winds are from cold air advecting into the Gulf. Same thing we get quite often in the Gulf when upper lows interact with frontal boundaries. More extratropical than subtropical. I'm fairly convinced this will amount to not much more than it is now as it moves ashore Thursday night. Not much of a concern to anyone.

[cycloneye]

[cycloneye]

8:05 AM TWD:

THE GULF OF MEXICO AND THE ATLANTIC OCEAN WEST OF 65W...
A DEEP LAYER TROUGH RUNS FROM THE WESTERN ATLANTIC OCEAN THROUGH
32N70W TO THE SOUTHEASTERN GEORGIA COAST THE FLORIDA GULF COAST
NEAR 29N83W TO A CYCLONIC CIRCULATION CENTER ON WATER VAPOR
IMAGERY NEAR 24N85W JUST NORTH OF THE WESTERN TIP OF CUBA...
TO THE SOUTHEASTERN YUCATAN PENINSULA TO SOUTH CENTRAL
GUATEMALA. MIDDLE TO UPPER LEVEL DRY AIR/SUBSIDENCE HAS BEEN
PUSHED INTO THE AREA UNDER NORTHERLY WIND FLOW ON THE WESTERN
SIDE OF THE 24N85W CYCLONIC CENTER. ISOLATED RAINSHOWERS
CONTINUE IN THE SOUTHEASTERN GULF WATERS AND THE STRAITS OF
FLORIDA...IN THE BAHAMAS...AND EVEN ALONG THE EAST COAST OF
FLORIDA AND COASTAL WATERS NORTH OF 28N. STRONG SHOWERS AND
THUNDERSTORMS IN CELLS FROM 22N TO 27N BETWEEN 67W AND 73W...
AND FROM 28N TO 30N BETWEEN 75W AND 80W. EXPECT NORTHEASTERLY
WINDS 20 TO 25 KT TODAY AND TONIGHT EAST OF 90W AND SEAS FROM
6 TO 10 FT. A STATIONARY FRONT PASSES THROUGH 32N70W TO 30N75W
TO 27N80W TO A 1006 MB LOW PRESSURE CENTER NEAR 25N80W. A SURFACE
TROUGH CONTINUES FROM THE LOW CENTER TO CUBA JUST WEST OF 80W
AND TO THE HONDURAS COASTAL WATERS NEAR 86W. IT IS POSSIBLE
THAT THE 1006 MB LOW CENTER MAY DEVELOP INTO A TROPICAL CYCLONE
AFTER 48 HOURS.

http://www.storm2k.org/wx/modules.php?n ... ge&pid=109

[Blown Away]

Is any of the convection in the E Bahamas related to the Karen remanents?

[Extremeweatherguy]

wxman57...why are you trusting the GFS speed so much? Remember how good it did (or didn't do) with what became Lorenzo? If the GFS had been right, then it should have come into the TX/LA border within a day or two and never had a chance to form into a hurricane in the BOC. However, we all know what actually happened with that. Now back in the current situation..why would the GFS speed this time be trusted more than some of the slower globals? Is there anything keeping this system from moving a little slower in the GOM and not speeding into SW LA in 60 hours?

[wxman57]

wxman57...why are you trusting the GFS speed so much? Remember how good it did (or didn't do) with what became Lorenzo? If the GFS had been right, then it should have come into the TX/LA border within a day or two and never had a chance to form into a hurricane in the BOC. However, we all know what actually happened with that. Now back in the current situation..why would the GFS speed this time be trusted more than some of the slower globals? Is there anything keeping this system from moving a little slower in the GOM and not speeding into SW LA in 60 hours?

GFS was pretty good with TD 10, and it's been very good with this system so far. It's already in the SE Gulf, moving more quickly than TD 10 ever did. With an almost identical setup to TD 10, I would expect similar results with this low. The only models disagreeing are the ECMWF and NOGAPS, the two models that had TD 10 wrong.

[mvtrucking]

Is any of the convection in the E Bahamas related to the Karen remanents?

I'll second that question?

[caneman]

This location from the NHC 8:00 TWDwouldn't place it in the Gulf.

TO A 1006 MB LOW PRESSURE CENTER NEAR 25N80W

[O Town]

I am a bit confused, with this graphic


And then these statements:
TO A 1006 MB LOW PRESSURE CENTER NEAR 25N80W
IT IS POSSIBLE THAT THE 1006 MB LOW CENTER MAY DEVELOP INTO A TROPICAL CYCLONE
AFTER 48 HOURS.

2 different areas. It looks like alot of convection associated with that ULL, its possible that it could be working down to the surface?

[JonathanBelles]

Overcast
76*F
Rh:91 % (earth science building-8:30a)
Wind : ne 10-15 mph (estimated)
Barometer: 29.87" (earth science building-8:30a)

Taken from SPC-Gibbs Campus

[Stormcenter]

Very very interesting.

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

[Stratosphere747]

The TWD is not a "in this moment" disco, and lags behind what is going on currently.

I don't see two areas and agree that whatever low that is out there seems to be pushing from the straits into the GOM. Should know soon enough if recon isn't called off.

[Ed Mahmoud]

This doesn't impress me, but, I guess for a future thread, is that 0Z GFS now showing something similar to Canadian for Florida next weekend.


And no, Texas will be fine. Another week into Autumn, the odds of the Florida Fury making it acros the Gulf will be nil.


If 12Z runs (besides CMC) show Florida weekend action, I may just start a new thread.

Anyway, South Florida radars are fritzy, as usual. Tampa long range may show something with a spin down around the Tortugas, but without bothering to find the sine of the radar angle, no, wait, I know adjacent, I don't know opposite, the tangent of the radar angle, that rotation may not come close to the surface.

[KatDaddy]

Decent winds.....36G45mph

Conditions at 42003 as of
(7:49 am CDT)
Wind Direction (WDIR): NE ( 40 deg true )
Wind Speed (WSPD): 31.1 kts
Wind Gust (GST): 38.9 kts

[rockyman]

What impresses me most with this system (as opposed to the last one), is the amount of heavy convection that has formed on the WEST side of the system. Could this convection/moisture "shield" the developing surface low near the Keys from the dry air over the Gulf?

BTW, I'm saying surface low near the keys based on this map (click on NWS fronts):
http://www.ssd.noaa.gov/goes/east/gmex/loop-vis.html

Also, of note, the above map now shows that the 1006 low has moved further west and has broken off from the front