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Tropical Tropical storm Claudette

Myfrotho704_ said:
That’s a nice double barrel jet w plenty of divergence aloft on top of that TC which would ensure it keeping or gaining strength over land, this might also play into a increased tornado threat View attachment 85455View attachment 85456
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That's what I was thinking the southern half of alabama is in play, some models push to near 4000 cape and with hodos looking like a snack. Leads to trouble. The spc convective outlook for that day the writer mentions tornadoes as being favorable.
 
Zander98al said:
That's what I was thinking the southern half of alabama is in play, some models push to near 4000 cape and with hodos looking like a snack. Leads to trouble. The spc convective outlook for that day the writer mentions tornadoes as being favorable.
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Also if it continues to strengthen as a post tropical storm on land, shear and inflow would be increased more. A very complex and interesting event. Things have synced into a weird combo,
 
The key is also finding a legit low level circulation for all the models to grasp onto… we’re still seeing some wild jumps from model to model about where this storm will be in 4-5 days because they don’t really have a specific point to go off of .. that will always create some confusion .. add into it an approaching cold front and placement will be key to what happens to us downstream
 
I've had a hard time getting into the storm cause my brain won't let me see it as anything but a mid-latitude system with a strong tropical wave riding a boundary. Come on. This is just a baroclinically-enhanced wave that's captured by the upper-level low. The upper level low is just capturing this sorry-excuse for a PTC while it's in Tropical waters, and momentarily strengthens the system by transferring energy at the upper levels, and wrapping up the system along a relatively diffuse boundary with converging winds that aid cyclonic curvature with shear blasts most of the moisture off to the East with the W and SW while moistures streams in from the SE. You look at every level on the model (250-10m), and it's similar to the mechanics you see in tornado set-up. In fact, I wouldn't be surprised if there's a slight risk put out for Floribama Coastline. The PTC is only going to maintain tropical storm identity for 8-12 hours I understand naming systems that impact communities for safety, but many of the storms that receive names just look like strong mid-latitude storms that originate from the tropics, or gain momentary tropical characteristics. I need a system to maintain identity for 24 hours that's distinct from a frontal boundary.

And Sandy is usually the counter to these types of arguments, but that's a storm that had separate and distinct tropicaly identity previous to enhancement by a trough merging upper level energy into the system.
 
NickyBGuarantee said:
The key is also finding a legit low level circulation for all the models to grasp onto… we’re still seeing some wild jumps from model to model about where this storm will be in 4-5 days because they don’t really have a specific point to go off of .. that will always create some confusion .. add into it an approaching cold front and placement will be key to what happens to us downstream
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This to me is an upper level system with two frontal boundaries (dry-line and tropical warm front). The LLC will focus as it is enhanced by the Upper Level Low while it interplays with a Ridge to form a pseudo (transient) negative tilt trough. Those aformentioned boundaries will collide and create a broad area of low pressure (convergence zone) East to West from Central LA to the Panhandle of FL, and the SW part of the system will be inundated with dry air that'll focus as a mechanism when it clashes with the tropical moisture from the SE. I have to imagine the lowest pressures will be closer to the SW, but it will be along an elongating area of low pressure. The primary driver for moving the area of lowest pressures and moisture will be the 250Mb wind maps and 400-700Mb Humidity.

So it looks like the are of convergence moves from Central and Eastern LA through AL and GA towards Western SC and NC. By day 4 and 5, it's heading of NC and VA and off the Delmarva and Jersey Coast. The focus for rain will be to the N, E and SE of this area of elongated low pressure, which is basically where the Tropical and Dry fronts are clashing.
 
AND THE 4AM
Capture.JPG
Capture.JPG
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
352 AM EDT Fri Jun 18 2021

Day 2
Valid 12Z Sat Jun 19 2021 - 12Z Sun Jun 20 2021

...THERE IS A MODERATE RISK FOR EXCESSIVE RAINFALL OVER THE
CENTRAL GULF COAST AND A MARGINAL RISK FOR EASTERN PORTIONS OF THE
OHIO VALLEY...

...Ohio, West Virginia and Pennsylvania...

Convection is expected to continue for this area. With the day 1
QPF over this region, FFG is expected to lower creating more
concerns for flooding potential. Latest QPF for this period shows
an additional 1 to 2 inches of precipitation falling on already
saturated grounds. The Marginal Risk area was left in play and
adjusted a bit to account for latest QPF guidance.

...Louisiana to Georgia...

Potential Tropical Cyclone 3 continues to trek across the SE CONUS
bringing heavy precipitation. Models have continued the easterly
trend in the track which has led to some adjustments to the
already in place Moderate Risk, Slight Risk, and Marginal Risk
areas to a more easterly tilt. Latest WPC QPF has 3 to 5 inches of
additional precipitation for portions of eastern MS, central AL,
up into GA. A few Hi-Res models show signals of 6 to 8 inches for
these areas, but with a bit more spread among the models,
confidence on these heavier signals remains on the lower end.

Chiari
 
Im going to go out on a huuuuuuge limb here and say alabama is going to see the continuing of it's spring tornado outbreaks and we're going to get a bunch of spinny boys from this spinny water boy. modernweenie
 
Zander98al said:
Im going to go out on a huuuuuuge limb here and say alabama is going to see the continuing of it's spring tornado outbreaks and we're going to get a bunch of spinny boys from this spinny water boy. modernweenie
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You can include Georgia in that as as well.....

The primary impact for north and central GA continues to be
periods of heavy rainfall as Gulf moisture surges across the area
Saturday night into Sunday. Please refer to the Hydrology section
below for details on the total rainfall forecast and impacts with
this system. Additionally, will have to monitor for a tornado
threat as the system passes through, primarily east of the low
where low-level shear will be maximized and co-located with at
least some amount of instability. The current wind forecast calls
for breezy conditions on Sunday, especially across portions of
central GA, with winds up to around 20 mph at times. This is below
Wind Advisory criteria, but will need to monitor the wind
forecast going forward.
 
Checking the 3km nam this morning there may be a substantial tornado risk along the coast and 100 so miles inland. STP is maxed out over portions of inland coast in alabama and Florida. Very tricky scenario.
 
Looks like the focal point for the stronger storms is along the warm front as it moves north. The experiential nado forecast may be picking up on things
 
Zander98al said:
Looks like the focal point for the stronger storms is along the warm front as it moves north. The experiential nado forecast may be picking up on things
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probably going to have some embedded sups in this band coming out of the gulf then a few random ones in bands east of it
3k refl.png
 
JHS said:
This will be staying south of most of NC and upstate SC. The 0z GFS also says no to most of us from the cold front on Tuesday too. The Euro is still slowly trending south with this system too.
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Amazing how the those National Hurricane Center aren't buying the southern track at all and that we will see excessive rainfall. Stop going off one or 2 model runs and actually look at the whole picture here.
 
Nws mobile on inland tornadoes. Guess I'll have my eyes on radar down south this evening as some of the first convective bands rotate through. Saturday may have the best overlap in parameters they sayScreenshot_20210618-080126-169.png
 
SD said:
Really pulling for the Euro here. Most other models stink for rain
View attachment 85466
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I mentioned this yesterday and I’ll say it again. Gulf tropical systems once inland always have a shield of heavy rain to the north and northwest of the center. Even with the more southern track like the EURO, which the NHC doesn’t seem to buying into right now, there should be significant rainfall even where this output shows it being mainly dry. The moist S to SE flow ahead of the center on this track would create a perfect upslope for north GA, SC upstate, and at least the southern half of the NC mountains and foothills. I don’t remember which storm last year coming out of the Gulf it was, but I remember how models were keeping those areas very dry 48-72 hours out only to see those spots end up with the heaviest rain even though the track pretty stayed on point.
 
iGRXY said:
Amazing how the those National Hurricane Center aren't buying the southern track at all and that we will see excessive rainfall. Stop going off one or 2 model runs and actually look at the whole picture here.
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Yeah I wouldn’t be looking at 1 model here there’s clear guidance pointing towards the system as a whole traveling through the Carolinas and at least creating a widespread showers and thunderstorms type of day around here … might not be as much rain as they are getting further south west but it won’t be nothing
 
NickyBGuarantee said:
Yeah I wouldn’t be looking at 1 model here there’s clear guidance pointing towards the system as a whole traveling through the Carolinas and at least creating a widespread showers and thunderstorms type of day around here … might not be as much rain as they are getting further south west but it won’t be nothing
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These things always over perform on the north and northwest sides. They much more spacious usually as well. I think widespread 2-5" is likely across most of the carolinas.
 
Wild Weather Monger said:
There's an obvious separate low-level low still way down at 21N and 95W. I wonder if it tries to develop as the main low moves steadily away?
www.tropicaltidbits.com

Satellite Loop for Gulf of Mexico | Tropical Tidbits

Gulf of Mexico Satellite Loop
www.tropicaltidbits.com www.tropicaltidbits.com
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If you go back and look at some old model runs I think that is what most of the slower left models keyed on. I found this old euro run where it has 2 closed sfc lows in an overall larger gyre.
ecmwf_z500_mslp_us_7 (1).png

Once that deep persistent convection got going north of the Yucatan though it basically took over
 
Forecast cape from 3km 12 nam has around 3000 joules in this area. Again I think there's a substantial risk for spin up torndoes maybe a stronger one. Helicity swaths match up with spc convective marginal risk area for our area.Screenshot_20210618-105949-375.pngstp.us_se.pngScreenshot_20210618-105841-341.png
 
SD said:
If you go back and look at some old model runs I think that is what most of the slower left models keyed on. I found this old euro run where it has 2 closed sfc lows in an overall larger gyre.
View attachment 85483

Once that deep persistent convection got going north of the Yucatan though it basically took over
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Sure enough. Good catch!
 
FLASH FLOOD WATCH IN EFFECT FROM SATURDAY AFTERNOON THROUGH
SUNDAY EVENING...

THE NATIONAL WEATHER SERVICE IN PEACHTREE CITY HAS ISSUED A

* FLASH FLOOD WATCH FOR PORTIONS OF CENTRAL GEORGIA, NORTH CENTRAL
GEORGIA, NORTHWEST GEORGIA AND WEST CENTRAL GEORGIA, INCLUDING THE
FOLLOWING AREAS, IN CENTRAL GEORGIA, BIBB, BUTTS, CRAWFORD,
JASPER, JONES, MONROE AND PEACH. IN NORTH CENTRAL GEORGIA,
CLAYTON, COBB, DEKALB, DOUGLAS, FAYETTE, GWINNETT, HENRY, NEWTON,
NORTH FULTON, ROCKDALE, SOUTH FULTON AND WALTON. IN NORTHWEST
GEORGIA, CARROLL, HARALSON, PAULDING AND POLK. IN WEST CENTRAL
GEORGIA, CHATTAHOOCHEE, COWETA, HARRIS, HEARD, LAMAR, MACON,
MARION, MERIWETHER, MUSCOGEE, PIKE, SCHLEY, SPALDING, STEWART,
TALBOT, TAYLOR, TROUP, UPSON AND WEBSTER.

* FROM SATURDAY AFTERNOON THROUGH SUNDAY EVENING.

* A TROPICAL LOW PRESSURE SYSTEM WILL BRING HEAVY RAINFALL TO
PORTIONS OF GEORGIA SATURDAY AND SUNDAY. RAINFALL TOTALS OF 3 TO 5
INCHES ARE EXPECTED OVER THE WATCH AREA, WITH HIGHER AMOUNTS TO 6
INCHES POSSIBLE OVER PORTIONS OF WESTERN GEORGIA. QUICKLY
ACCUMULATING RAINFALL WILL EASILY ALLOW FOR EFFICIENT RUNOFF AND
INCREASE FLASH FLOODING POTENTIAL.

* CREEKS AND STREAMS MAY RISE OUT OF THEIR BANKS AND INUNDATE
FIELDS, ROADS, BUSINESSES AND OTHER PROPERTY. STREET FLOODING
COULD ALSO LEAD TO ROAD CLOSURES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.
 
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SD said:
Really pulling for the Euro here. Most other models stink for rain
View attachment 85466
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I believe on Tropical Tidbits, that yellow is like 8-10" or something like that. Pivotal here has it around 4". Meh

Interesting how it just seems to stop, though.
 
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