Cristobal Remnants June 9-10

[Hoosier]

Tropical Storm Cristobal Tropical Cyclone Update
NWS National Hurricane Center Miami FL AL032020
510 PM CDT Sun Jun 07 2020

...CENTER OF CRISTOBAL MAKES LANDFALL IN SOUTHEAST LOUISIANA...

Satellite, radar, and surface data indicate that the center of 
Tropical Storm Cristobal made landfall at 500 PM CDT (2200 UTC) 
along the coast of southeast Louisiana between the mouth of the 
Mississippi River and Grand Isle. Maximum sustained winds were 
estimated near 50 mph (85 km/h) with a minimum central pressure of 
992 mb (29.29 inches). 

[A-L-E-K]

Gonna be sick when the gulf is a few hundred miles north and we do this on the reg

[purduewx80]

51 minutes ago, HillsdaleMIWeather said:

3K NAM is also much less linear, looks like a broken line of supercells

At the end of its range, but the RPM is highly cellular 18-21Z in IL/IN:

[A-L-E-K]

Yes

[purduewx80]

There is probably another severe weather threat later Tuesday evening into Wed ahead of the neg til upper trough. There looks to be a boundary left behind by Cristobal that forms a triple point near St Louis thru much of IL/IN/MI into the OH Valley Wed PM - watch that for possible spinups too. Lapse rates steepen and the wide open Gulf will have left mid-70s dews in the wake of Cristobal, so instability will actually build overnight. 

[luckyweather]

Gonna be sick when the gulf is a few hundred miles north and we do this on the reg

OT and you probably already know this but it was almost here already, southern IL/Memphis/the MO bootheel on down, everything there south is sedimentary deposition as the MS/delta just keeps building south. Highly visible on sat/terrain/Topo imagery.

[madwx]

hi res models are on the east end of guidance and if they are correct we are going to get poured on

[Hoosier]

Anyone know the water temp of the Mississippi River in the IA/IL area?  Looks like Cristobal could ride close to it for a while.   

[luckyweather]

Anyone know the water temp of the Mississippi River in the IA/IL area?  Looks like Cristobal could ride close to it for a while.   

https://rivergages.mvr.usace.army.mil/WaterControl/stationinfo2.cfm?sid=DLDI4&fid=DLDI4&dt=S

78 degrees at dbq which seems way high, but Bellevue IA is 77, so I guess it’s right.

https://rivergages.mvr.usace.army.mil/WaterControl/stationinfo2.cfm?sid=BLVI4&fid=BLVI4&dt=S

[purduewx80]

 

[snowlover2]

End of the 0z HRRRv4 shows numerous cells in east IN and a line forming in east MO.

[Hoosier]

It is a little weird seeing a forecast sounding like this around here.  Temp in the low 90s with mixing up to around 775-750 mb on SE/SSE flow.  If you just showed me the sounding I'd be wondering what the hell kind of setup this is lol 

[snowlover2]

Slight risk up for IL/IN on new day 2.

Quote

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1254 AM CDT MON JUN 08 2020  
 
VALID 091200Z - 101200Z  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF  
ILLINOIS...INDIANA...AND WESTERN KENTUCKY...AND FROM SOUTHEAST  
NEBRASKA INTO NORTHEAST KANSAS...  
   
..SUMMARY  
 
SCATTERED STRONG TO SEVERE STORMS ARE EXPECTED TUESDAY OVER PARTS OF  
THE MISSOURI, MID MISSISSPPI AND OHIO VALLEYS DURING THE DAY AND  
EVENING, WITH A FEW TORNADOES POSSIBLE IN ADDITION TO LOCALIZED WIND  
DAMAGE. HAIL IS POSSIBLE AS WELL OVER PARTS OF NEBRASKA AND KANSAS,  
WITH ISOLATED STRONG STORMS INTO SOUTHERN AND EASTERN TEXAS  
OVERNIGHT.  
   
..SYNOPSIS  
 
THE REMNANTS OF CRISTOBAL, SURFACE AND ALOFT, WILL CONTINUE  
NORTH/NORTHEAST ACROSS MO AND IL DURING THE DAY, ENHANCING LIFT AND  
SHEAR PROFILES, AND BRINGING SUBSTANTIAL LOW-LEVEL MOISTURE NORTH.  
MEANWHILE, A POTENT SHORTWAVE TROUGH WILL BE OVER THE CENTRAL PLAINS  
BY 00Z, AND WILL CONTINUE EAST TOWARD THE MS VALLEY WITH RAPID  
HEIGHT FALLS.  
 
AT THE SURFACE, THE LOW ASSOCIATED WITH CRISTOBAL WILL MOVE FROM MO  
INTO EASTERN IA THROUGH 00Z, WITH A WARM FRONT ROUGHLY FROM LOWER MI  
INTO SOUTHERN WI. WINDS ALOFT WILL RAPIDLY VEER OVER THE MS VALLEY  
WITH THE PASSAGE OF THE FIRST WAVE, THEN BACK AGAIN AFTER 00Z AS THE  
MAIN TROUGH APPROACHES.  
 
VARIOUS MODEL SOLUTIONS EXIST REGARDING THE BEST AREA OF STORM  
POTENTIAL AND DESTABILIZATION. HOWEVER, THE GENERAL IDEA IS FOR A  
FEW SUPERCELLS DURING THE DAY WITH TORNADO THREAT FROM THE MID MS  
INTO THE LOWER OH VALLEY AREAS, WITH A DAYTIME THREAT ACROSS NE AND  
KS NEAR THE UPPER TROUGH.  
   
..IL...IN...WESTERN KY...PARTS OF ADJACENT STATES  
 
STORM POTENTIAL IS EXPECTED TO SHIFT FROM NORTHERN MS AND TN INTO  
KY, IL AND IN THROUGHOUT THE DAY, WITH A MOIST ENVIRONMENT AND  
LOW-LEVEL SHEAR SUPPORTING ROTATION. MODELS SUGGEST THE BEST SRH  
(OVER 300 M2/S2) WILL BE OVER WESTERN KY, EASTERN IL, AND MUCH OF IN  
BY LATE AFTERNOON, AND WILL CONTINUE NORTH INTO LOWER MI AFTER 00Z  
WHERE INSTABILITY WILL BE LESS. AMPLE MOISTURE WILL SUPPORT STORMS  
SCATTERED OVER THE ENTIRE AREA, BEGINNING IN THE MORNING OVER  
NORTHERN MS AND WESTERN TN, THEN RAPIDLY SHIFTING NORTH.  
 
OVERNIGHT, A VERY MOIST AIR MASS WILL REMAIN, AND MAY SUPPORT  
ADDITIONAL STRONG TO SEVERE STORMS AS THE COLD FRONT ARRIVES INTO  
WEDNESDAY MORNING.  
   
 

 

[Hoosier]

Pressure has only risen by 2 mb since landfall about 8 hours ago.  May see it come up another mb or two but that should be about it before it deepens.

[purduewx80]

1 hour ago, Hoosier said:

It is a little weird seeing a forecast sounding like this around here.  Temp in the low 90s with mixing up to around 775-750 mb on SE/SSE flow.  If you just showed me the sounding I'd be wondering what the hell kind of setup this is lol 

Agreed! Those 0-3 km lapse rates of 8.5C/km should enable some of the initial showers to produce strong wind gusts. 

[purduewx80]

There's still quite a bit of difference in the 00Z guidance in how this evolves on Tuesday, both intensity- and forward motion-wise. Wind fields are still much stronger on the ECMWF/UKMET than other guidance, owing to a deeper low. The reality will probably end up some blend of current model progs. 

Based on everything I've seen so far, I think the tornado probabilities valid ~18Z Tuesday - 12Z Wednesday are something like below. The 10% area is where you have the best combo of instability and helicity (a 700 mb west-southwesterly wind max comes in atop a southerly 850 LLJ and SSE'rly 925 LLJ). Some guidance does suggest higher probs into northern IL but there will probably be some sort of shadow near Lake Michigan due to ageostrophic E to SE'rly sfc winds. 

 

[A-L-E-K]

most of the high-res guidance has a nice convective look over the area tomorrow afternoon, should be a fun day of wx

[A-L-E-K]

[purduewx80]

LOT/Ratzer has a nice, in-depth discussion of model preferences and what could change/differ given the continued spread:

Quote

National Weather Service Chicago/Romeoville, IL
608 AM CDT Mon Jun 8 2020

.SHORT TERM...
235 AM CDT

Today through Wednesday night...

Warm dry weather starts off the week today, before attention
quickly shifts to the remnants of tropical storm Cristobal Tuesday
into Tuesday evening and the potential for high winds, locally
heavy showers, and even a few tornadoes.

In the near term, upper level Rex blocking is in place today,
with the upper level ridge north of tropical storm Cristobal
centered over IN and IL. Subsidence and resulting warming beneath
the 5880- 5900 meter upper ridge will make for dry and warmer
weather across the forecast area. Progged H8 temps of +20C to
+22C, and H9 temps near +25C should support afternoon highs in the
lower 90`s, except along and near the IL lake shore where
southeast surface winds will limit readings to the upper 70s.
Sunshine will be plentiful, though patchy high clouds will begin
to increase from the south later this afternoon as the northern
periphery of Cristobal`s cirrus canopy edges north into the
region. Dry and mild conditions continue tonight, with patchy high
clouds and modest southeast winds.

Guidance remains in reasonably good agreement with the track of
Cristobal during the day Tuesday, taking it from central Missouri
to near Dubuque Iowa by evening, and then quickly north of the
forecast area later Tuesday night. The 00Z GFS however is faster
with the strong short wave which emerges from the south-central
Plains later in the day however, with the GFS becoming
increasingly more of an outlier during the period, and thus not
utilized for this period of the forecast. The official NHC track
is slightly east of the non-GFS model consensus, with the center
tracking across northwest IL while transitioning to a post-
tropical depression. The strong Plains short wave is then progged
to lift northeast into northern Missouri by Wednesday morning,
becoming negatively-tilted and moving across the forecast area
during the day Wednesday. 00Z runs of the ECMWF/CMC are reasonably
similar with the track/intensity of this vigorous short wave and
are favored, while the 00Z NAM becomes a deeper and slower
outlier. Overall, the slower evolution of the short wave from
model runs 24 hours ago results in less interaction/deepening of
the surface low associated with Cristobal`s remnants north of the
forecast area by Wednesday, with a weaker low induced by the wave
across Wisconsin. The wave then exits the region to the northeast
Wednesday night.

The greatest sensible weather impacts are expected to be focused
during the Tuesday afternoon and evening periods, with the passage
of Cristobal`s remnants. These include high winds, heavy tropical
rain showers, and the potential for brief tornadoes. With respect
to the rain, a plume of deep tropical moisture with precipitable
water values of 2.25-2.50", or nearly 250% of normal, is progged
to spread into the forecast area Tuesday afternoon and early
evening. With deep warm cloud depths supporting
collision/coalescence and very efficient rainfall rates, showers
should be capable of producing brief torrential rains. Guidance
continues to favor areas along and west of the low track for the
most persistent precipitation and heaviest QPF amounts, with WPC`s
QPF ranging from roughly 0.50 to an inch across our eastern cwa,
to 1.25-2.25" for portions of north central IL west of the Chicago
area. Flood potential will likely be higher west of the cwa,
though high rainfall rates in torrential showers will have the
potential to produce localized flooding across the cwa. WPC does
have our western cwa included in their slight risk for exceeding
flash guidance. Rainfall should lighten up/taper off late Tuesday
evening, as Cristobal`s remnants and deeper tropical moisture
plume lift north/northeast of the forecast area.

Wind wise, there appears to be two periods of enhanced winds with
Cristobal`s remnants Tuesday afternoon and evening, then again
with the strong negative-tilt short wave Wednesday afternoon and
evening. Forecast soundings depict a deep layer of SSE 40-50+ kt
winds above about 1000` agl Tuesday afternoon/evening. It`s hard
to gauge how much of this will mix down in a prevailing manner,
though certainly any convective showers and thunderstorms will
have the potential to produce fairly strong and potentially
damaging gusts. Some potential for better mixing exists Tuesday
afternoon over the eastern cwa where slightly warmer temps are
likely, which may aid in translating stronger gusts to the
surface. It will be interesting to monitor surface winds south of
our region this afternoon for trends which may apply here
tomorrow. Certainly the potential for winds meeting wind headline
criteria exists, though confidence is somewhat low at this time.
In addition the the threat of damaging wind gusts however, is the
potential for brief tornadoes to develop Tuesday afternoon and
early evening as well. Forecast SRH in the 0-1 km layer increases
into the 300-400 m2/s2 with speed/directional shear, within a very
moist low level environment. SPC has placed the entire LOT cwa in
their day 2 risk for this wind and tornado potential, with areas
southeast of I-55/I-80 in east central IL and northwest IN in a
slight (5%) risk where somewhat better low level instability is
expected. It`s entirely possible the slight risk could be expanded
farther north with later updates.

The second period of high wind potential, Wednesday afternoon and
early evening, is in association with strong pressure rises and
deeper mixing in low level cold advection behind the strong short
wave and deepening surface low lifting away from the area. This
period could also approach wind advisory criteria with westerly
winds gusting 40-45 mph. Winds would then slowly diminish
Wednesday night as the system pulls away to the northeast.

Ratzer

IND and ILX also discuss possible risk upgrades in subsequent SPC outlooks. I agree.

[Chicago Storm]

The bullish Euro has backed off on the winds, and is falling more in line with the rest of the pack.


Looking more likely we end up with a usual 40-55mph wind event, locally higher.

There does appear to be some tor threat, but greatest will be much further S and SE.


.

[luckyweather]

The bullish Euro has backed off on the winds, and is falling more in line with the rest of the pack.


Looking more likely we end up with a usual 40-55mph wind event, locally higher.

There does appear to be some tor threat, but greatest will be much further S and SE.


.

Probably not taking into account the likely strengthening to a category 5 monster as a consequence of its dwell time over the hot Mississippi River waters.

[cyclone77]

Looks like Hawkeye won't be mentioning lack of heavy rain anymore for awhile.  Looks like that area will be ground zero for 3-5" of rain.  

Looks like 1/2-1" or so here, as we'll be very close to the track.  Maybe some 30-40mph gust potential.  Normally pretty much would be a non-event, but the tropical aspect of it is pretty sweet.

[janetjanet998]

12Z NAM and clones have another small area of interest over NE IL WEDS afternoon

this is missing on GFS

[Hoosier]

18 minutes ago, janetjanet998 said:

12Z NAM and clones have another small area of interest over NE IL WEDS afternoon

this is missing on GFS

NAM has had shaky handling of this setup imo (not that the GFS has been stellar).  Besides what you mentioned, it looks like a weak outlier with the remnants of Cristobal.

[sbnwx85]

If nothing else 90 degrees, humid and windy will make it feel like I’m in Key West for a day. 

[CheeselandSkies]

2 hours ago, Chicago Storm said:

The bullish Euro has backed off on the winds, and is falling more in line with the rest of the pack.


Looking more likely we end up with a usual 40-55mph wind event, locally higher.

There does appear to be some tor threat, but greatest will be much further S and SE.


.

Naturally.

What has happened to "King" Euro? Time was, if it was the one showing an impact event you sat up and took notice. And if the GFS was popping PDS TOR soundings everywhere you said  "Meh, I'll wait and see what the Euro says."

[wisconsinwx]

4 minutes ago, CheeselandSkies said:

Naturally.

What has happened to "King" Euro? Time was, if it was the one showing an impact event you sat up and took notice. And if the GFS was popping PDS TOR soundings everywhere you said  "Meh, I'll wait and see what the Euro says."

Even when it was King it was normally for winter events, I don't think it's ever been stellar for summer (and particularly concerning convection).

[Hoosier]

Tomorrow night is a pretty classic way on how to not have a quick nocturnal temp drop.  After most of the precip goes by, could see temps rise again as conditions remain decently mixed.  Would not be surprised if temps hang in the upper 70s to around 80 here for a good chunk of the overnight.

[hawkeye_wx]

1 hour ago, cyclone77 said:

Looks like Hawkeye won't be mentioning lack of heavy rain anymore for awhile.  Looks like that area will be ground zero for 3-5" of rain.  

Looks like 1/2-1" or so here, as we'll be very close to the track.  Maybe some 30-40mph gust potential.  Normally pretty much would be a non-event, but the tropical aspect of it is pretty sweet.

Models are all over the place with rain totals.  The UK and Euro are still bullish for me, but the rest are shifting to central Iowa, with only 0.50-1.50" here.

[Hoosier]

2 minutes ago, hawkeye_wx said:

Models are all over the place with rain totals.  The UK and Euro are still bullish for me, but the rest are shifting to central Iowa, with only 0.50-1.50" here.

I'd probably lean heavier across the board. Even with the relatively quick system speed the rain is very efficient given how tropical the air mass is.