ATL: OLGA - Post-Tropical - Discussion

[GCANE]

04A KYARR 191025 1200 16.3N 71.9E IO 55 987
17L INVEST 191025 1200 24.7N 94.8W ATL 30 1006
22W BUALOI 191025 1200 35.3N 149.8E WPAC 55 983
98L INVEST 191025 1200 36.0N 33.0W ATL 30 1009
98W INVEST 191025 0600 10.0N 138.3E WPAC 15 1010

[GCANE]

PTC17L on Levi's site

https://www.tropicaltidbits.com/sat/sat ... product=ir

[GCANE]

Two feeder bands

[Aric Dunn]

im amazed... lol

[GCANE]

There is actually quite a bit of humid air advecting into this across the front.
It appears the newly developing western feeder band is a product of that.
That, and given there is no UL Vort to interfere with LL Vort, some surprises maybe in store.

[SoupBone]

The system that is moving through the Midwest and East is a positively tilted one that doesn't have a lot of push like the one that was associated with Nestor. This front will not make it through the eastern half of the GOM and the Florida peninsula so it will not clear out those areas of heat and humidity. In fact, it will act to draw more moisture and rain into the southeast as the low heads NNE. No strong cold front for the foreseeable future.

Yeah, the cold front's section north of 97L over the upper TX coast is already slowing down.

I hit 49 degrees this morning in North Houston.

[Aric Dunn]

Likely a TS at this point..

[GCANE]

Mesoscale Discussion 2115
NWS Storm Prediction Center Norman OK
0853 AM CDT Fri Oct 25 2019

Areas affected...southeast Louisiana...southeast
Mississippi...southwest Alabama and the far western Florida
Panhandle

Concerning...Severe potential...Watch possible

Valid 251353Z - 251600Z

Probability of Watch Issuance...60 percent

SUMMARY...The threat for isolated tornadoes is expected to increase
along the central Gulf Coastal area through the morning and continue
into the afternoon. Trends are being monitored for a possible
tornado watch.

DISCUSSION...As of mid morning a warm front extends along the
central Gulf Coast then southwestward into southeast Louisiana and
is expected to move slowly northward through the morning. As a
result, a very moist warms sector with low 70s F dewpoints will
advect inland resulting in modest instability (1000-1500 J/kg
MLCAPE). Meanwhile, discrete storms including a few supercells, are
developing along convergence bands over the Gulf that extend
northward, intersecting the warm front along the central Gulf coast.
A mid-level shortwave trough preceding the primary upper trough will
advance northeast through the north central Gulf region today. A
35-40 kt low-level jet will persist downstream from this feature,
maintaining favorable 0-1 km hodographs for low-level mesocyclones
and a few tornadoes, especially as storms interact with the warm
front. Short-term tendency might be for storms to weaken as they
move onshore, confining the tornado threat to near the coast.
However, trend should be for storms to survive farther inland as the
warm front moves north through mid day.

..Dial/Grams.. 10/25/2019

...Please see http://www.spc.noaa.gov for graphic product...

[Steve]

The system that is moving through the Midwest and East is a positively tilted one that doesn't have a lot of push like the one that was associated with Nestor. This front will not make it through the eastern half of the GOM and the Florida peninsula so it will not clear out those areas of heat and humidity. In fact, it will act to draw more moisture and rain into the southeast as the low heads NNE. No strong cold front for the foreseeable future.

Yeah, the cold front's section north of 97L over the upper TX coast is already slowing down.

I hit 49 degrees this morning in North Houston.

Brrrr.

[wxman57]

Obs offshore do. Not indicate a low separate from the front. Supergeostrophic winds are often found behind these early-season fronts. Winds offshore will be twice that observed onshore. 50-60 it winds are common in the cold air flowing over very warm water. Happens every fall. This west Gulf low is no different.

[GCANE]

Its the battle of the LL Vorts.
Round 1.
Looks like 17L is winning.
Let the CCW rotation dance begin.

[Frank P]

Per NHC TD 17 has formed in the GOM... update coming...who knew?

[Aric Dunn]

It has been separate from the trough from the beginning and still is. Fully tropical warm core ..at least for the next 12.. maybe 24 hours.

[northjaxpro]

I think we may possibly get a TS out of this before the frontal merger after all.

[Frank P]

I think this might be a record for being the latest storm to be named this late in the season in the western GOM... IF...

[Hurricanehink]

I think this might be a record for being the latest storm to be named this late in the season in the western GOM... IF...

Inga in 1961 formed at 94.7° W in early November.

[HurricaneEnzo]

I think we'll be adding 2 more named systems to the season total before the day is over. Both TD17 and 98L are looking nameable at this point. If they are going to name systems like Colin and Nestor this should be a shoo-in if they can find tropical storm force winds somewhere.

[mpic]

I have never like winter but also never been so glad to see a cold front. Imelda was enough.

[Hypercane_Kyle]

...TROPICAL DEPRESSION FORMS IN THE WESTERN GULF OF MEXICO... ...EXPECTED TO BECOME A GALE-FORCE POST-TROPICAL LOW TONIGHT...
10:00 AM CDT Fri Oct 25
Location: 25.6°N 94.4°W
Moving: N at 16 mph
Min pressure: 1006 mb
Max sustained: 35 mph

It's like Nestor... but even weaker and more pathetic.

[tropicwatch]

Looking forward to see what HH finds.