janetjanet998

latest DVN Hydro..

HYDROLOGY  
  
ISSUED AT 146 PM CDT MON SEP 3 2018  
  
SINCE 6 AM TODAY, ADDITIONAL HEAVY RAIN HAS FALLEN OVER THE  
AREAS GENERALLY NORTH OF HIGHWAY 30 IN IOWA AND ILLINOIS THIS  
MORNING. THE AFTERNOON ACTIVITY THUS FAR IS EITHER NEAR AND WEST  
OF WATERLOO, AND OVER OUR ILLINOIS COUNTIES. STORMS ARE SMALL IN  
SIZE, QUICK MOVING AROUND 30 TO 35 MPH, AND ARE PRODUCING  
TORRENTIAL RAINFALL RATES. THIS CONTINUES TO OFFER A FLASH FLOOD  
POTENTIAL.   
  
THE RAIN WHICH FELL IN NARROW SWATHS OVERNIGHT, FELL IN WIDE  
SWATHS THIS MORNING, AND NARROW AFTERNOON SWATHS IS ENOUGH TO HAVE  
MORE OR LESS INCREASED THE WIDESPREAD NATURE OF THE RIVER  
FLOODING. MINOR TO MODERATE FLOODING IS NOW EXPECTED ON MOST  
TRIBUTARIES IN IOWA AND ON THE ROCK AND PECATONICA IN ILLINOIS.   
  
ON THE LOWER STRETCHES OF THE IOWA, SKUNK, WAPSI, AND ROCK,  
SIGNIFICANT MODERATE FLOODING IS FORECAST, AND IN SOME CASES,  
LEVELS JUST UNDER MAJOR. THESE ARE IN PARTICULAR NEED OF CLOSE  
MONITORING, AS THEY COULD POSSIBLY EXCEED MAJOR IN THE WEEK AHEAD,  
MAINLY IF WE GET HEAVY RAINS JUST AHEAD OF THE CRESTS.   
  
THE MISSISSIPPI RIVER IS NOW EXPECTED TO REACH MODERATE FLOOD  
LEVELS AT NEW BOSTON, KEITHSBURG, GLADSTONE LD/18, AND BURLINGTON.  
GREGORY LANDING HAS MINOR FLOODING EXPECTED.  
  
THE FORECAST REMAINS WET FOR WELL INTO THE EXTENDED, EVEN AFTER A  
BIT OF A BREAK IN THE NEXT 24 HOURS. THUS, THERE IS WATER YET TO  
FALL THAT IS NOT ACCOUNTED FOR IN THESE FORECASTS. THEREFORE,  
CHANGE IN CREST AND TIMING ARE LIKELY IN THE WEEK AHEAD.  
  
ERVIN  

15 minutes ago, kevlon62 said:

Nothing like a backyard tor warned chase. This at 31 south of McHenry.

Sent from my SM-G935P using Tapatalk
 

you guys have had alot of rain and it looks like a mini train is moving in

concerned for the Rock River...and Des plaines and Fox rivers in Northern IL...later on

17 minutes ago, hawkeye_wx said:

I'm thinking the eye-like feature may be mostly aloft.  The rest of the core on radar just doesn't really match up with that kind of intensity, and neither does the satellite presentation.  There's also a buoy near the coast just north of the center and it still says 1014 mb.

I was tracking hurricane Humberto in 2007 minute by minute of HOU....this seems to be doing the same thing...expect this wont run into land in 8 hours...the inner core has formed before most of the middle-outer core(..expect the north east side)..lets see if it fills in

perhaps the friction affect helped that process start quickly

There is often talk of Ocean heat content ..but IMO often that's over hyped....small faster moving systems don't really care how deep the warm water is...

49 minutes ago, hawkeye_wx said:

I'm hoping Gordon's remnants can get up to Iowa.  We obviously don't need the rain, but it's a rare occurrence for this area.  They almost always veer east before reaching Iowa.

he seems to be getting his act together rather fast

not sure if a stronger system would mean a more east track?

seems to be on the east side of the thin cone now too

the mesoscale chaos throws a monkey wrench into smaller river forecast but its easier to focus on the main stems..

The Missouri river above Kansas city is already in flood(tempered by the low volume Kansas river(so far) from MCI downstream)  

also IMO the Mississippi river above STL could  have issues (tempered by rather low inflow from the MO river(so far) from STL downstream)

  
HYDROLOGY  
  
ISSUED AT 330 AM CDT MON SEP 3 2018  
  
MAINLY MINOR TO MODERATE FLOODING CONTINUES OR REMAINS FORECASTED  
OVER THE NEXT 7-10 DAYS ON MANY TRIBUTARY RIVERS, WITH MINOR   
FLOODING FORECASTED ON THE SOUTHERN MAINSTEM MISSISSIPPI. HOWEVER,  
RIVER LEVELS AND FORECASTS COULD POTENTIALLY GO HIGHER IN THE NEXT  
5-7+ DAYS AS WE ADD ADDITIONAL RAINFALL.   
  
HEAVY RAINFALL SUNDAY AFTERNOON AND NIGHT YIELDED ANOTHER ROUND OF   
1 TO 4 INCH RAIN AMOUNTS, HOWEVER THESE OCCURRED IN FAIRLY NARROW   
SWATHS LARGELY JUST CLIPPING PORTIONS OF SEVERAL TRIBUTARY RIVER  
BASINS MOST NOTABLY THE PECATONICA. HAVING LARGELY SPARED THE TRIBS  
WITH THIS ADDITIONAL RAINFALL FORECASTS ARE LARGELY UNCHANGED OR  
COMING IN A BIT LOWER, AND SEEING A FEW SITES (KALONA, SIGOURNEY  
AND DEWITT) CREST OR RECEDE WITH LOWER LEVELS AS RUNOFF ABATES.  
HOWEVER, ADDITIONAL SECONDARY RISES AT THESE SITES ARE EXPECTED   
THROUGH ROUTED FLOW AND/OR ADDITIONAL FORECASTED RAINFALL.   
  
AS FOR THE NEXT 24 HOURS WILL SEE ANOTHER ROUND OF SHOWERS AND STORMS  
TODAY. DO NOT ANTICIPATE WIDESPREAD HEAVY RAIN RATHER MORE SWATHS OR  
NARROW CORRIDORS OF 1-4 INCH RAINFALL TOTALS. THUS, A GOOD CHANCE   
THIS RAIN WON'T HAVE A LOT OF IMPACT ON RIVER LEVELS UNLESS IT OCCURS  
DIRECTLY OVER A BASIN IN WHICH CASE COULD RESULT IN ADDITIONAL AND   
RAPID RISES AND HIGHER STAGES.   
  
ENCOURAGING DRIER SIGNAL IS PRESENT FOR TONIGHT THROUGH TUESDAY NIGHT  
WITH ONLY SPOTTY PRECIPITATION, AS DRIER AIR ADVECTS IN FROM HIGH   
PRESSURE OVER THE MID ATLANTIC. THE SURFACE BOUNDARY AND MOIST   
CONVEYOR WILL REFOCUS THE MORE ORGANIZED WIDESPREAD HEAVY RAIN POTENTIAL  
TO OUR NORTH AND WEST.   
  
CONCERN BEYOND IS FOR ADDITIONAL ROUNDS OF HEAVY RAIN TAKING AIM YET  
AGAIN ON THE REGION OVER THE LATTER HALF OF THE WEEK AND THROUGH THE  
UPCOMING WEEKEND WITH BOUNDARY STALLED NEARBY AND POTENTIAL FOR TROPICAL  
REMNANTS LIFTING NORTHWARD AND INTERACTING WITH THE FRONT. SHOULD THIS  
OCCUR THEN WE COULD POTENTIALLY BE LOOKING AT AN INCREASED RISK OF   
SIGNIFICANT FLASH FLOODING AND MAJOR RIVER FLOODING. SOMETHING THAT WILL  
BE MONITORED VERY CLOSELY IN THE COMING DAYS.  

0Z Nam aggressive with the front cleaning IA by Weds evening

ESOSCALE PRECIPITATION DISCUSSION 0747...CORRECTED  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
601 PM EDT SUN SEP 02 2018  
  
CORRECTED FOR NEEDED RECREATION OF MPD GRAPHIC  
  
AREAS AFFECTED...EASTERN IA/SOUTHERN WI/NORTHERN IL  
  
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE  
  
VALID 022138Z - 030325Z  
  
SUMMARY...TRAINING AND REPEATING ROUNDS OF HEAVY RAIN WILL CAUSE A  
THREAT FOR FLASH FLOODING FROM EASTERN IA INTO SOUTHERN  
WI/NORTHERN IL THROUGH 03Z. 2-4 INCHES OF ADDITIONAL RAINFALL ARE  
POSSIBLE.  
  
DISCUSSION...LOCAL RADAR IMAGERY AT 21Z SHOWED TWO MCVS OVER IA,  
ONE ALONG THE WESTERN IA/MO BORDER AND THE OTHER ALONG THE IA/WI  
BORDER, BOTH MOVING TOWARD THE NORTHEAST. EACH MCV WAS CONNECTED  
TO CLUSTERS OF HEAVY RAINFALL WITH DUAL-POL ESTIMATED RAIN RATES  
OF 1-2 IN/HR WITHIN THE HEAVIER CORES. TRENDS OVER THE PAST HOUR  
HAVE SHOWN CONVECTION FILLING IN BETWEEN THE TWO MCVS OVER CENTRAL  
IA. THE SPC MESOANALYSIS AT 21Z DEPICTED A SIZABLE AREA OF 2000+  
J/KG MLCAPE JUST SOUTH OF THESE MCVS.  
  
WHILE RECENT RUNS OF THE HRRR HAVE STRUGGLED TO CAPTURE THE  
MAGNITUDE OF RAINFALL OCCURRING OVER IA AND WI, THE IDEA OF FUTURE  
EVOLUTION IS HINTED AT IN ITS SIMULATED REFLECTIVITY OUTPUT. BOTH  
MCVS ARE EXPECTED TO CONTINUE A TRACK OFF TOWARD THE  
EAST-NORTHEAST WHILE 25-30 KT 850 MB FLOW FROM THE SOUTHWEST  
OVERRUNS A REMNANT OUTFLOW BOUNDARY ENHANCED BY DIFFERENTIAL  
HEATING. GIVEN THE 850-300 MB MEAN WIND IS ROUGHLY 20-30 KT (A  
ROUGH PROXY FOR STORM MOTIONS), SOME TRAINING/REPEATING OF HEAVY  
RAIN CORES IE EXPECTED. IN ADDITION, DIFFLUENT FLOW ALOFT IS  
EXPECTED TO ENHANCE AS AN UPPER LEVEL JET TO THE NORTH STRENGTHENS  
THROUGH 03Z AS FORECAST BY THE RAP. FLASH FLOOD GUIDANCE IS RATHER  
LOW OVER THE REGION (1.5 TO 2.5 INCHES IN 3 HOURS) HELPING SUPPORT  
THE THREAT FOR FLASH FLOODING WITH 2-4 INCHES OF ADDITIONAL  
RAINFALL POSSIBLE THROUGH 03Z.  
  

WPC still has 5-7 inches 7 day totals over IA area...hints of SE push and pattern change days 6-7

A little out of our sub forum but same event 

MESOSCALE PRECIPITATION DISCUSSION 0746  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
501 PM EDT SUN SEP 02 2018  
  
AREAS AFFECTED...CENTRAL KS/SOUTHEAST NE/NORTHWEST MO/SOUTHERN IA  
  
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY  
  
VALID 022055Z - 030255Z  
  
SUMMARY...AN INCREASING COVERAGE OF THUNDERSTORMS IS EXPECTED  
THROUGH 00Z AND 03Z ACROSS CENTRAL KS INTO SOUTHEASTERN NE,  
SOUTHERN IA AND NORTHERN MO. 3-5 INCHES OF RAIN IS EXPECTED  
THROUGH 03Z, SOME OF WHICH WILL OVERLAP WITH RECENT HEAVY RAINFALL  
ACROSS THE REGION POSING AN INCREASED THREAT FOR FLASH FLOODING.  
  
DISCUSSION...2030Z VISIBLE SATELLITE IMAGERY AND SURFACE  
OBSERVATIONS PLACED A SURFACE TROUGH, ENHANCED BY DIFFERENTIAL  
HEATING, FROM WEST-CENTRAL KS INTO NORTHWEST MO. RADAR IMAGERY  
ALREADY SHOWED SCATTERED THUNDERSTORMS ACROSS CENTRAL KS,  
INCREASING IN COVERAGE OUT AHEAD OF A STRUNG OUT LOW-MID LEVEL  
TROUGH AXIS WITH A COUPLE OF VORTICITY CENTERS STRETCHING ACROSS  
THE CENTRAL HIGH PLAINS. THE 20Z SPC MESOANALYSIS SHOWED 1500-2500  
J/KG MLCAPE ACROSS KS INTO MO AND SOUTHERN IA WITH ERODING CIN  
CONFIRMED BY THE RECENT INCREASE IN THUNDERSTORM DEVELOPMENT  
ACROSS KS. EAST OF 100W, GPS SITES AND THE 18Z LMN SOUNDING SHOWED  
PRECIPITABLE WATER VALUES OF 1.5 TO 1.8 INCHES ACROSS KS/NE/IA/MO.  
  
INCREASED FORCING FOR ASCENT OVER THE CENTRAL PLAINS AND MIDWEST  
IS EXPECTED THROUGH 00Z AS SUBTLE EASTWARD MOVEMENT OF THE  
MID-LEVEL TROUGH AXIS OCCURS. THE RAP HAS BEEN TRENDING STRONGER  
WITH A FORECAST 70-90 KT UPPER LEVEL JET FORECAST TO LIE FROM  
NORTHWEST IA TO LAKE SUPERIOR, PLACING THE RIGHT ENTRANCE REGION  
AND ADDED UPPER LEVEL DIVERGENCE OVER CENTRAL KS/NE BETWEEN  
00-03Z. MEANWHILE, CLOSER TO THE SURFACE, 850 MB WIND SPEEDS  
SHOULD INCREASE FROM THE SOUTH INTO THE 20-30 KT RANGE ACROSS KS  
BEYOND 00Z WITH OVERRUNNING OF THE AFOREMENTIONED SURFACE TROUGH  
AND ANY NEWLY DEVELOPED CONVECTIVE OUTFLOW BOUNDARIES WITH NEARLY  
UNIDIRECTIONAL FLOW ABOVE THE LFC SUPPORTING TRAINING/REPEATING OF  
CELLS FROM SOUTHWEST TO NORTHEAST. 3-5 INCHES OF RAIN THROUGH 03Z  
IS EXPECTED IN A FEW LOCATIONS, SOME OF WHICH IS EXPECTED TO  
OVERLAP WITH RECENT HEAVY RAINFALL AND LOWERED FLASH FLOOD  
GUIDANCE, SUPPORTING FLASH FLOODING IN A FEW LOCATIONS.  
  

new DVN long term

HE LONG RANGE OFFERS LITTLE HOPE FOR MORE THAN A SHORT REPRIEVE   
FROM THIS EXCEPTIONALLY WET PATTERN. THAT DAY IS TUESDAY, WHEN THE   
UPPER HIGH IS EXPECTED TO NUDGE A BIT FARTHER WEST, HELPING PUSH THE   
FOCUS FARTHER WEST FOR ORGANIZED STORMS.   
  
BEYOND THE DETAILS THIS IS WHAT IS IMPORTANT.  
  
HEAVY RAIN WILL IMPACT THE MIDWEST EVERY 24 HOUR PERIOD THIS WEEK.  
  
THE SYNOPTIC PATTERN SUGGESTS THE SAME DIURNAL INCREASE AND DECREASE   
IN CONVECTION IN THE RING OF FIRE PATTERN WILL CONTINUE THROUGH   
THURSDAY, AS THE UPPER HIGH SHIFTS SLIGHTLY EAST ALLOWING OUR AREA   
TO ONCE AGAIN BE THE MAIN FOCUS FOR HEAVY RAINFALL. THE PWAT VALUES   
ARE NOT EXPECTED TO LOWER AND THE DURATION OF THIS AIR MASS IS QUITE   
CONCERNING. CERTAINLY WE WILL CONTINUE TO HAVE WIDESPREAD RIVER   
FLOODING.  THE MOST CONCERNING POTENTIAL I SEE IN THE EXTENDED, AS   
IT WOULD SUGGEST A FAR MORE WIDESPREAD HIGH CONFIDENCE HEAVY RAIN   
EVENT, IS THE POSSIBLE PRE RAIN EVENT THURSDAY NIGHT THROUGH SATURDAY   
NIGHT. A PRE, OR PREDECESSOR RAINFALL EVENT, IS WITH LANDFALLING   
TROPICAL FEATURES MOISTURE PLUME AS IT INTERACTS WITH THE WESTERLY   
FLOW ALOFT NORTH OF THE TROPICAL HIGH, WHICH IS MORE OR LESS THE   
CURRENT RING OF FIRE PATTERN.   
  
RAINFALL IN THE WEEK AHEAD COULD ADD UP TO OVER 5 INCHES IN MANY   
LOCATIONS NORTH OF HIGHWAY 34.  STILL, MESOCALE DETAILS WILL   
DETERMINE STORM INITIATION EACH DAY, AND THOSE LOCATIONS WILL SEE   
THE HIGHEST IMPACTS. THAT UNFORTUNATELY IS BEYOND THE ABILITY TO BE   
FORECAST BEYOND A DAY, AND WILL RESULT IN THE THREAT FOR HEAVY RAIN   
TO BE FORECAST IN A MORE WIDESPREAD AREA THAN IS WILL VERIFY UNTIL   
THURSDAY.  AFTER THURSDAY, THE PRE EVENT COULD OFFER A LESS   
CONVECTIVE, BUT MORE WIDESPREAD HEAVY RAIN EVENT.   

19 minutes ago, hawkeye_wx said:

The euro continues to be extremely bullish with the rain through the entire week.  While the GFS, and even the Canadian, have been hinting the rain may be swept away to the east and south as early as Wednesday night, the euro keeps an upper disturbance parked over NE/KS/IA, which pumps high moisture into Iowa like a conveyor.  Today's 12z run has widespread 5-12 inches of rain across the state through Saturday.

seems it also keeps a southerly flow  in the plains days 8-9 while the GFS Builds in a high...in not sure what the moisture and precip are though,..I assume it is shunted east and has to rebuild 

This also seems to plow  Florance into the east coast ...while the GFS is well east with the stronger trough east

12z ECWMF also has a shreared out version of that tropical system near STL at 192 hours..major difference between it and GFS at days 8-9 

DVN HYDROLOGY  
  
ISSUED AT 103 PM CDT SUN SEP 2 2018  
  
TORRENTIAL RAINS FELL ONCE AGAIN OVER THE AREA LAST NIGHT. THESE  
RAINS FELL ON THE UPPER REACHES OF TRIBUTARY RIVERS THAT FLOW INTO  
OUR CWA, MOST PROLIFICALLY ON THE ENGLISH, IOWA, WAPSIPINICON AND  
ROCK RIVERS. RAINFALL OF 1 TO 2 INCHES WAS COMMON, WITH SOME 3 TO  
4 INCH REPORTS IN IOWA COUNTY, AND JO DAVIESS/STEPHENSON COUNTIES.  
THESE RAINS, COMBINED WITH ONGOING HIGH WATER, AND FORECAST  
RAINFALL AHEAD ARE RESULTING IN HIGHER THAN NORMAL CONFIDENCE IN  
RIVERS REACHING FLOOD STAGE,MODERATE FLOOD STAGE AND EVEN MAJOR IN  
ONE CASE. FOR THAT REASON, WE HAVE BYPASSED USING THE WATCH WITH  
RESPECT TO A FEW POINTS THAT ARE AROUND 3 DAYS OUT FROM REACHING  
FLOOD LEVEL. THIS WET PATTERN IS HIGH ENOUGH CONFIDENCE THAT  
FORECASTS ARE MORE LIKELY TO INCREASE THAN FALL SHORT ONCE ALL THE  
WEEK'S RAINS FALL.   
  
THE ENGLISH RIVER AT KALONA GOT HIT WITH FLASH FLOODING RAINS  
AGAIN LAST NIGHT, THEREFORE, HITTING 18 FEET OF MAJOR SEEMS LIKELY  
AND WE HAVE ISSUED A WARNING REACHING MAJOR. MARENGO IS IN A  
SIMILAR POSITION ON THE IOWA RIVER, BUT IS EXPECTED TO REMAIN  
MODERATE TODAY. IN ADDITION, MODERATE FLOODING IS EXPECTED ON THE  
IOWA RIVER AT OAKVILLE AND WAPELLO. ON THE SKUNK, SIGOURNEY SHOULD  
ALSO NOW REACH MODERATE, POSSIBLY NEAR MAJOR. ONCE AGAIN, FUTURE  
RAINS MAY FORCE HIGHER LEVELS.   
  
THE WAPSI AT DEWITT 4S SAW MODERATE STAGE RISE YESTERDAY, AND IS  
FALLING, BUT ROUTED WATER WILL ONCE AGAIN CAUSE MODERATE FLOODING  
IN THE NEXT FEW DAYS.   
  
THE MISSISSIPPI IS RISING, AND WITH SO MANY TRIBS SHOOTING UP, IS  
LIKELY TO BE ADJUSTED FARTHER. FOR NOW, THE CONFIDENCE ON MINOR  
FLOOD IS HIGH ENOUGH TO ISSUE WARNINGS FOR NEW BOSTON ON  
DOWNSTREAM, EXCEPT FOR KEOKUK.  
  

Both the 12z GFS and CMC have that tropical system up this way with the GFS more east...

at least it takes the high PW moisture with it as it moves east next weekend

45 minutes ago, hawkeye_wx said:

The first two nights of storms and heavy rain have really dumped on some areas, but Cedar Rapids has been stuck in the dry hole, just downstream of the heavy storms, both nights.  I was only able to get 0.12" last night.

12z NAM and WPC discussion: well day/night 3 of the train may be missing a few box cars over IA/IL ..still heavy rains though in IA/IL/WI ..seems KS/NE get smoked ..

tomorrow looks like the train is back around you

tuesday it may shift north and west

I should note there is a tropical disturbance near LA and the NAM takes some of this moisture and seems to increase PW values even more coming up into the midwest ...but it does push the train well SE by 84 hours as high pressure builds into MN

Long term AFD from DVN mentions tropical  system

ONG TERM  
(MONDAY THROUGH NEXT SATURDAY)  
ISSUED AT 330 AM CDT SUN SEP 2 2018  
  
THE LATEST SUITE OF MEDIUM RANGE MODELS KEEP THE MID SUMMER-LIKE  
RING OF FIRE GOING FOR MUCH OF THE UPCOMING WEEK IN OR NEAR THE  
LOCAL AREA OF CONCERN. STILL SOME HOPE THAT MID LEVEL RIDGE   
RETROGRADE OR AMPLIFICATION SHUNTS THE MAIN HEAVY RAIN AXIS JUST   
TO THE WEST AND NORTH OF THE LOCAL AREA, BUT PORTIONS OF THE CWA   
WILL STILL BE SUSCEPTIBLE TO AT LEAST GETTING CLIPPED BY STORMS   
AND MORE BOUTS OF HEAVY RAIN, ESPECIALLY THE NORTHWEST AND   
NORTHERN THIRD OF THE FCST AREA THROUGH WED. THERE COULD BE ALMOST  
THE DAILY NEED FOR A FLOOD WATCH FOR PORTIONS OF THE AREA FOR   
MUCH OF THE UPCOMING WEEK. COMPOUNDED ROUNDS OF HEAVY RAIN IN OR   
NEAR THE AREA WILL IMPACT RIVER BASINS WITH ROUTED FLOW, OR   
LOCALIZED RAIN PRODUCING INCREASED RIVER FLOODING AS THE WEEK   
PROGRESSES. WILL ALSO HAVE TO WATCH FOR THE TROUBLING SIGN OF   
REMNANTS OF A TROPICAL SYSTEM GETTING DRAWN UP TOWARD THE AREA BY  
NEXT WEEKEND OR THE WEEK AFTER, WHICH COULD REALLY COMPOUND   
FLOODING PROBLEMS IN AN AREA HIT BY OCCASIONAL BOUTS AND SWATHS   
OF HEAVY RAIN FOR OVER A WEEK. THE 00Z GFS BREAKS THE FLOODING   
PATTERN BY SEPT 10TH OR 11TH WITH A BIG COOL DUMP/LONG WAVE TROF   
OUT OF CANADA.  
  

NO change to WPC precip maps maps.MOD risk for excessive rainfall today, Slight tomorrow , and then moderate again tuesday

NWS Weather Prediction Center College Park MD
439 AM EDT Sun Sep 02 2018
 
Day 1
Valid 12Z Sun Sep 02 2018 - 12Z Mon Sep 03 2018 

...MODERATE RISK OF EXCESSIVE RAINFALL OVER THE MID MS VALLEY... 

...Central Plains into the Mid MS Valley and Great Lakes...
Another active convective day from portions of the Central Plains 
into the Great Lakes. Overall a similar setup to what we have been 
seeing the past few days with the region in between the upper 
level troughing over the west and ridging over the east. The 
synoptic setup is probably not quite as good over IA/WI/IL as it 
has been...with the upper jet displaced a bit further north and 
weaker 850mb moisture transport forecast. But will continue to 
have a boundary in place, weak to moderate low level flow into the 
boundary, and another shortwave pushing northeast across the area. 
PWs will also be equal or even a bit higher compared to yesterday. 
Thus appears likely that additional convection will occur across 
IA into southern WI and northern IL this afternoon and overnight. 
Like the synoptic situation, the high res model signal is not 
quite as robust over the area today either...but still suggesting 
an additional 1-3"...and still the potential for localized 3-5" 
totals given the persistent (albeit weaker) moisture transport 
supportive of some training/backbuilding and higher PWs. Given the 
heavy antecedent rainfall over central and southern IA, this 
additional rainfall likely poses an elevated flash flood threat. 
For this reason have opted to upgrade to a Moderate Risk for much 
of southern and central IA, with additional flash flooding likely 
today. Some potential this may need to be expanded into portions 
of northern IL and southern WI as well...although at this time the 
signal for 3"+ additional amounts is lower here, and thus will 
maintain a Slight for now.

The heaviest rainfall magnitudes over the day 1 period may 
actually end up falling further south across central KS into far 
southeast NE. 850mb moisture transport is more impressive across 
this corridor...and the persistent and stationary nature of this 
moisture transport axis is very favorable for backbuilding and 
training convection. Thus would appear like a corridor of longer 
duration heavy rains is possible, with both the 0z HREF and HRRR 
indicating pockets of 5"+ totals. Current indications are that 
this activity should end up mainly south of where the heaviest 
antecedent rainfall has been. For this reason will keep the risk 
level at Slight across KS and southeast NE. But will need to 
monitor through the day...as the setup does have the potential to 
warrant an upgrade even if the rainfall falls over drier grounds. 
And if there were to be a shift north in the axis into areas that 
were recently hit hard, then additional flash flooding would 
certainly become likely and warrant an upgrade. Thus will keep an 
eye on trends and reevaluate as the day progresses. 

Round 2 starting ... WPC still has that same stripe of 5 to 7 inches over the next 7 days 

looks like they keep the tropical low over Texas  via the 6/7 day QPF 

after the previous training days.....both the 12z CMC and GFS develop a tropical system in the gulf and move it up this way...GFS further east and faster 

CMC/GEM solution seems to have the flow around it overriding a front with epic precipitation amounts

12 NAM favors N IL  back into IA with a 4-7 inch thin stripe before the train moves North and West monday as the ridge builds back a little more NW on the East Coast,,

it seems to be a hair too far north with this mornings MCS though...

it seems the OMA NE area gets overlapped with the tracks (west-east moving then south-north)  and the NAM cracks out 7-10  inches around there

Large MCS over IA into NW IL and SW WI. 3-4 inches down in areas.'...isolated 6-7 inches ......with widespread 1+ inch amounts

Waterloo IA 3.02 inches since midnight

The MCS would start to weaken here this morning and become more progressive as it moves east into CHI metro

However this will prime the ground for whatever develops this afternoon and tonight for round 2...which the exact location won't be known until later 

WPC has still has 5+ inches the next 7 days from NE into WI..with a bullseye of 7 inches over SW IA

IMO extreme rainfall amounts are possible the next week if the train tracks don't fluctuate north/south much each day

MKE update pretty much sums it up

REA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI  
646 PM CDT FRI AUG 31 2018  
   
UPDATE  
  
STILL SOME UNCERTAINTY WITH HOW THINGS WILL EVOLVE OVERNIGHT  
TONIGHT, BUT THERE IS GROWING CONSENSUS THAT THE AREA SHOULD BE  
MOSTLY DRY THROUGH MIDNIGHT. AFTER MIDNIGHT, THUNDERSTORMS WILL  
BEGIN TO BLOSSOM AS THE LOW LEVEL JET IS ABLE TO TAP INTO A SOLID  
1500-2000 J/KG OF ELEVATED CAPE. WITH SUFFICIENT BULK SHEAR, A FEW  
STRONGER STORMS WILL BE POSSIBLE. GIVEN THE ELEVATED NATURE TO THE  
THUNDERSTORMS, THE SEVERE WEATHER THREAT SHOULD BE LIMITED TO   
LARGE HAIL.  
  
OF GREATER CONCERN IS THE POTENTIAL FOR HEAVY RAIN. PWATS WILL  
INCREASE TO 2"+ OVERNIGHT, WITH SLOW STORM MOTIONS. THERE MAY ALSO  
BE SOME POTENTIAL FOR BACKBUILDING, AS CORFIDI VECTORS FALL TO  
LESS THAN 10 KNOTS BY THE PRE-DAWN HOURS. ALL OF THIS SUGGESTS  
THAT SOME LOCATIONS WILL LIKELY SEE PERIODS OF VERY HEAVY RAIN,  
BUT WITH LITTLE IN THE WAY OF SURFACE FEATURES TO ORGANIZE  
CONVECTION, IT'S TOUGH TO PINPOINT ANY SPECIFIC AREA THAT HAS THE  
HIGHEST POTENTIAL AT THIS TIME. THE FLASH FLOOD WATCH IS WELL-  
PLACED WITH THOSE AREAS THAT HAVE THE LEAST TOLERANCE FOR  
ADDITIONAL RAINFALL, AND THESE AREAS WILL CERTAINLY BE OF   
GREATEST CONCERN FOR IMPACTS SHOULD THEY SEE THE RAIN OVERNIGHT

2 hours ago, hawkeye_wx said:

I'm actually getting a bit worried about the first round.  Tonight was going to be our first big night, but the latest 3k nam and hrrr show nothing here.  They have convection blowing up over sw Iowa, which would then move east and southeast, leaving us dry.  Heck, the 3k nam also has nothing Saturday night.

well, as you know,  short range models often perform poorly in these set ups due to unpredictable meso features....for example,  there seems to be a disturbance over NE IL this evening that the models missed or were too weak with...... 1-2 inches of "bonus" rains down(could prime the ground even more if later rains also hit there) and a t-storm warning thrown it for good measure 

if a few hours the LLJ should show its hand and give clues for the overnight train location

no change really from the new WPC maps...4-5 inches from NE into WI next 7 days...

the 18z NAM products are rather concerning for eastern IA into N IL....a little south trend

models didn't handle the MO convection well today and that held up the warm front some from moving north ....

The potential exists for very heavy rain and eventually river flooding over MN, IA, WI and N IL maybe ENE into MI

The pattern seems stuck with a strong high off the East coast with tropical moisture flowing north into the midwest...

Due to recent heavy rains , soil moisture is high and some smaller rivers are in flood in WI.(Kickapoo had record flooding a few days ago)..Northern MO area has been in a drought but heavy rains this morning are weakening the "drought shield" for that area

A ring of fire type pattern is setting up..WPC 7 day rainfall amounts are 4-5 inches from eastern NE into WI(of course isolated higher amounts)

Medium range models suggest this pattern may continue for at least the next 10 days....with mesoscale outflows likely playing a role where the daily heavy rain train sets up

Of course any tropical systems moving around the ridge later on may also add to all of this too

In Summary: major daily flash flood events likely....developing into main stream river flooding events

surprise 

many mini low topped hooking SUPS

ISOLATED SEVERE THUNDERSTORMS, CAPABLE OF DAMAGING WINDS AND A FEW   TORNADOES, ARE POSSIBLE ACROSS PARTS OF ALABAMA, THE FLORIDA   PANHANDLE, AND SOUTHWEST GEORGIA INTO THIS EVENING.       ..DISCUSSION     RECENT SINGLE-RADAR AND MRMS DATA HAVE DISPLAYED AN ORGANIZATIONAL   UPTICK IN SHALLOW SUPERCELLULAR ACTIVITY ACROSS THE REGION. IN FACT,   A TORNADIC DEBRIS SIGNATURE WAS RECENTLY OBSERVED WITH A CELL OVER   CRENSHAW CO, AL, SUGGESTING SOME INCREASE IN TORNADO POTENTIAL IS   BEING REALIZED THIS AFTERNOON. KEVX DATA DISPLAY A WIND PROFILE   FAVORABLE FOR THE SUSTENANCE OF LOW-LEVEL MESOCYCLONES, AND   BOUNDARY-LAYER MOISTURE IS CERTAINLY ADEQUATE FOR TORNADOGENESIS   WITH THESE ISOLATED CELLS, AS WELL AS NEW DEVELOPMENT MOVING ONSHORE   FROM THE NORTHERN GULF. THEREFORE, A SLIGHT RISK HAS BEEN INTRODUCED   FROM SOUTHEAST ALABAMA TO SOUTHWEST GEORGIA AND THE FLORIDA   PANHANDLE.    

it may be off its peak right now  but still......

C031-081-070100-  
/O.CON.KSHV.TO.W.0044.000000T0000Z-180407T0100Z/  
DE SOTO LA-RED RIVER LA-  
754 PM CDT FRI APR 6 2018  
  
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 800 PM CDT FOR EAST  
CENTRAL DE SOTO AND CENTRAL RED RIVER PARISHES...  
          
AT 754 PM CDT, A CONFIRMED LARGE AND EXTREMELY DANGEROUS TORNADO WAS  
LOCATED OVER COUSHATTA, OR 21 MILES EAST OF MANSFIELD, MOVING EAST AT  
20 MPH.  
  
THIS IS A PARTICULARLY DANGEROUS SITUATION. TAKE COVER NOW!  
  
HAZARD...DAMAGING TORNADO.   
  
SOURCE...RADAR CONFIRMED TORNADO.