Jump to content
  • Member Statistics

    17,502
    Total Members
    7,904
    Most Online
    Weathernoob335
    Newest Member
    Weathernoob335
    Joined

Late April-Early May Heavy Rain/Severe Possibilities


Recommended Posts

  • Replies 210
  • Created
  • Last Reply
3 minutes ago, jojo762 said:

Supercell west of Shawneetown, IL could be one to watch...

Speak of the devil

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Paducah KY
808 PM CDT FRI APR 28 2017

The National Weather Service in Paducah has issued a

* Tornado Warning for...
  South central White County in southeastern Illinois...
  Central Gallatin County in southern Illinois...
  Southern Posey County in southwestern Indiana...
  West central Henderson County in northwestern Kentucky...
  North central Union County in northwestern Kentucky...

* Until 845 PM CDT
    
* At 808 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Ridgway, or near Shawneetown, moving northeast at
  60 mph.

  HAZARD...Tornado and golf ball size hail. 

  SOURCE...Radar indicated rotation. 

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely. 

* Locations impacted include...
  Mount Vernon, Shawneetown, Uniontown, Ridgway and Junction. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 3768 8825 3780 8831 3800 8785 3784 8774
TIME...MOT...LOC 0108Z 240DEG 53KT 3777 8823 

TORNADO...RADAR INDICATED
HAIL...1.75IN

Link to comment
Share on other sites

Ohio Valley through all night with have widespread thunderstorms. Significant Tornado risk will be highest near the Ohio River it looks like it, maybe extending further east through the night. The clouds are on rocket mode where i am at.

Link to comment
Share on other sites

14 minutes ago, Indystorm said:

Yes, that sw IN storm approaching Mt. Vernon and EVV is just to the sw of the greatest helicity, often the site of strong tornadoes.   With a LLJ kicking in and a WF boundary this could get serious.

VWP at KLVX is very impressive depicting a large sickle shaped hodograph with nearly 500 m2/s2 0-1KM SRH.

Link to comment
Share on other sites

00Z NAM no longer has the extreme rainfall since it moves the train around rather then in a continuous location.  The result is a wider area of heavy but not extreme rainfall amounts

 

the 1st part of the train is over central IL the second near the quad cities....of course the 2nd part could be held up by outflows and actually be SE too....time to nowcast

Link to comment
Share on other sites

well people that live along the IL river downstream to Peoria are in a panic because of the record to near record flood forecast..i have family members that get isolated/surrounded at 27.5 feet at PIA...one has a business trip later next week and doesn't know if he should cancel because of this

Silly  for the NWS to do that at this point( I HOPE I JUST DIN'T JINX IT AND WE HAVE A 1000 YEAR FLOOD NOW) before any rain has fallen in the basin and based 100% of future model projections ....already this morning heavy rains are stalled way downstate because storms are holding off the progress north of the front north(as what happens most of the time)

Even the NWS discussion out of LOT says the heaviest Rains may stay south so its perplexing why the LOT/ILX forecast went so bullish

 

If widespread 5-8 amounts don't fall between PIA and the SW burbs of Chicago, then no record flooding

besides it takes 4-6 days for the river to reach Crest around here after the rain stops so it's not like its flashy flooding

 

The best bet would have to taken a middle or a "3/4"  approach yesterday/now then make adjustments as needed

 

 

 

 

 

Link to comment
Share on other sites

1 hour ago, janetjanet998 said:

well people that live along the IL river downstream to Peoria are in a panic because of the record to near record flood forecast..i have family members that get isolated/surrounded at 27.5 feet at PIA...one has a business trip later next week and doesn't know if he should cancel because of this

Silly  for the NWS to do that at this point( I HOPE I JUST DIN'T JINX IT AND WE HAVE A 1000 YEAR FLOOD NOW) before any rain has fallen in the basin and based 100% of future model projections ....already this morning heavy rains are stalled way downstate because storms are holding off the progress north of the front north(as what happens most of the time)

Even the NWS discussion out of LOT says the heaviest Rains may stay south so its perplexing why the LOT/ILX forecast went so bullish

 

If widespread 5-8 amounts don't fall between PIA and the SW burbs of Chicago, then no record flooding

besides it takes 4-6 days for the river to reach Crest around here after the rain stops so it's not like its flashy flooding

 

The best bet would have to taken a middle or a "3/4"  approach yesterday/now then make adjustments as needed

 

 

 

 

 

Definitely a bit strange to go all in with the mediocre performance of the models thus far. 

 

Slightly OT; but the last time I saw some crazy flooding in Peoria, I was in college living on the hilltop. Entire riverfront was flooded, with a series of scaffolding constructed so that we could get to the now closed "old Chicago". Lots of damage.

Link to comment
Share on other sites

Well, I picked up 1 1/3 " here just ne of Indpls with a conveyor belt of rain from here sw to OK still to come.  Much heavier near the Ohio River as has been mentioned.  We have a 998 mb low just off the TX Big Bend that refuses so far to budge.  But models show it is supposed to get moving by Sunday.  71 for a high here today and forecast high of 82 Sunday.  Only 57 now.  Had a friend on the west side of Indpls whose home was struck by lightning last night and fried the television and landline phone but luckily no fire.  13,000 without power down around the Columbus IN area.   Hard to believe that warm front will eventually surge north as forecast.  As I look at the current  9:30 am CDT St.Louis and Springfield MO radars it seems the next heavy batch of rain is moving more north and west than last night. So it may move up the Illinois River Valley.  Something to watch regarding those flood predictions for PIA area if it keeps moving northward today and tonight.

Link to comment
Share on other sites

1 hour ago, janetjanet998 said:

12Z NAM still  hits Quincy to Peoria to Chicago hard with rain 5+ inches 

but seems a bit to far NW with the precip over IL at this time

12z GFS more SE with the 5 inch axis and is probably correct...missing the IL river basin above PIA

 

14z HRRR looks to be in bewteen

Link to comment
Share on other sites

..HIGH RISK AND TREMENDOUS RAIN/FLOOD EVENT EXPECTED FROM EASTERN  
OKLAHOMA INTO THE WESTERN OH VALLEY...  
  
EARLY 12Z MODEL GUIDANCE PICK UP ON WHAT APPEARS A SLIGHT  
REALIGNMENT AND NORTHWESTWARD SHIFT TO THE RISK AREAS IN  
ACCORDANCE WITH THE MAIN SYNOPTIC BOUNDARY DRAPED AND  
STRENGTHENING FROM OKLAHOMA NORTHEASTWARD. OTHERWISE, THE FORECAST  
APPEARS ON TRACK WITH A PREFERENCE TOWARD THE OVERNIGHT HI-RES  
NSSL WRF AND HI-RES ARW RUNS FOR TRACKING RAIN RATES AND TIMING,  
WHICH ARE DISPLACED QUITE A BIT SOUTH OF THE 12Z NAM. THE REST OF  
THE OVERNIGHT DISCUSSION IS APPENDED BELOW.   
  
PREVIOUS:  
  
ALL THE INGREDIENTS ARE MAXIMIZED. A 3.5 STANDARD DEVIATION UPPER  
LOW WITHIN A STRONGLY BUCKLING LARGE SCALE FLOW PATTERN / COUPLED  
JET STRUCTURE...HEADING INTO A LENGTHY STALLED FRONTAL ZONE WITH  
MOISTURE AND INSTABILITY CHARACTERISTIC OF MID SPRING. FLOW OFF  
THE GULF...ORIGINATING IN THE CARIBBEAN...IS UNUSUALLY  
STRONG...SQUEEZED BY A 1032 MB HIGH OVER THE WESTERN ATLANTIC. THE  
ENSEMBLE SITUATION AWARENESS INFORMATION BASED ON THE NAEFS HAS AN  
AWFUL LOT OF 99TH PERCENTILE AND MAX VALUES FOR INTEGRATED VAPOR  
TRANSPORT WITHIN THE CONVEYOR BELT FROM EAST TEXAS UP THROUGH  
EASTERN OK / WESTERN AR AND INTO MISSOURI. AMPLIFICATION OF THE  
LARGE SCALE SYNOPTIC SYSTEM WILL ALSO RETARD EASTWARD  
PROGRESSION...RESULTING IN VERY INTENSE AND PERSISTENT RAINFALL  
THIS AFTERNOON AND EVENING...WHICH WE SUSPECT WILL BE CENTERED  
AROUND NORTHWEST ARKANSAS BASED ON OBSERVATIONAL AND MODEL TRENDS.  
THE LOCATION OF THE HEAVIEST RAIN VARIES BETWEEN MODELS...BUT  
WITHIN THE WARM CONVEYOR BELT THEY ALL...GLOBAL AND HI-RES MODELS  
ALIKE...HAVE A SIGNAL FOR WIDESPREAD 5-PLUS INCH RAINS WITH  
EMBEDDED 7 TO 10 INCH AMOUNTS. A FURTHER CONCERN IS THE BREADTH OF  
THE 5-PLUS INCH RAINFALL...WHICH MAY AFFECT PARTS OF THREE  
STATES...COVERING A LOT OF TERRITORY...RESULTING IN A LARGE VOLUME  
OF WATER INTO CERTAIN WATERSHEDS.  
  
AS PRECIPITABLE WATER INCREASES TO NEAR 1.75 INCHES...AND 2.5  
STANDARD DEVIATIONS ABOVE AVERAGE FOR LATE APRIL...EXPECT HOURLY  
RAIN RATES TO PUSH ABOVE 3 INCHES GIVEN THE HIGH LIKELIHOOD OF  
TRAINING. THE EVENT IS EXPECTED TO PEAK THIS AFTERNOON AND EVENING  
AS THE LARGE SCALE SYSTEM REACHES MATURITY AND FLOW BECOMES VERY  
MERIDIONAL DURING PEAK HEATING / PEAK INSTABILITY. THE HEAVIEST  
RAIN IS FORECAST IN AREAS THAT ARE NOT ONLY PRONE TO FLASH  
FLOODING DUE TO TERRAIN...BUT ARE ALSO WET FROM ANTECEDENT HEAVY  
RAIN EARLIER IN THE WEEK AND RAIN ALREADY OCCURRING EARLY SATURDAY  
MORNING. THUS...LIFE-THREATENING CONDITIONS MAY BECOME COMMON  
LATER TODAY AND TONIGHT WITHIN THE HIGH RISK AREA.  
  
MODERATE RISK EXTENDS A LITTLE DEEPER INTO EASTERN AND SOUTHERN  
OKLAHOMA...AND UP ACROSS SAINT LOUIS TO ILLINOIS...WHERE EXTREME  
RAIN TOTALS ARE LESS LIKELY...BUT AVERAGE RAINFALL OF AT LEAST 2  
TO 5 INCHES IS FORECAST...INCLUDING VERY HEAVY SHORT TERM RATES.  
THE GROUND IN SOME OF THESE AREAS ARE ALSO WET FROM PRIOR RAINFALL.  
   

Link to comment
Share on other sites

1 hour ago, janetjanet998 said:

12Z NAM still  hits Quincy to Peoria to Chicago hard with rain 5+ inches 

but seems a bit to far NW with the precip over IL at this time

I'd probably lean more on the CAMs/short range runs at this point, but will need a healthy amount of nowcasting.

Example...HRRR has this through 8z tomorrow, which puts the better rains south of the NAM

hrrr_apcpn_ncus_18.thumb.png.adcd6e6323be68c03204530849e93510.png

Link to comment
Share on other sites

Wanted to offer comment on the very high river forecasts that went out. This is not meant to throw the North Central River Forecast Center under the bus. However, all forecasts for this area are issued by NCRFC in collaboration with NCRFC. They decided to go with 72 hour qpf for this event to catch the storm total but the qpf used in their forecast hydrographs yesterday was extremely high. They went with that bullish forecast and we didn't have too much advanced notice of it, but what we did do is go with flood watches instead of warnings because the forecasts are entirely qpf driven. In hindsight, we could have done a better job of working with NCRFC to play things more conservatively to start out and then adjust upward as trends became more clear. For example, perhaps we could've requested to just use 48 hour qpf, or to adjust the qpf for the models down 25% or thereabouts. Given the potential impacts of the stages being forecast, I definitely understand the angst and criticism, especially if it doesn't work out due to convection south robbing the moisture transport.

Sent from my SM-G935V using Tapatalk

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...