Iowa WX

River Flooding Continuing

iowawx — Sat, 13 Mar 2010 06:20:41 +0000

Aside from the ice jam flooding that is occurring in Fort Dodge and Mason City tonight, other rivers continue rising over their banks across the state. Numerous rivers continue under Flood Warnings, many through next week at the latest.

Here are the following rivers that are under Flood Warnings (Forecast Points)
Squaw Creek at Ames
Cedar River at Cedar Falls
Cedar River at Waterloo
Beaver Creek at New Hartford
Iowa River near Rowan
Iowa River at Marshalltown
West Fork Cedar River at Finchford
Winnebago River at Mason City
Shell Rock River at Shell Rock
Des Moines River near Eddyville
North River near Norwalk
Raccoon River at IA Hwy 28
Raccoon River at Fleur Dr (DSM)
North Raccoon River near Perry
Des Moines River near Stratford
Des Moines River at Emmetsburg
Des Moines River at Estherville
East Fork Des Moines River near Algona
Boone River near Webster City
East Fork Des Moines River at Dakota City
Beaver Creek near Grimes
Raccoon River at Van Meter
Des Moines River at Humboldt
Des Moines River at Fort Dodge
Des Moines River at SE 6th (DSM)
North Raccoon River near Jefferson
South Skunk River at US Hwy 30 (Ames)
South Skunk River at Colfax
South Skunk River near Oskaloosa
Cedar River near Conesville
Iowa River at Marengo
Cedar River at Cedar Rapids
Iowa River near Lone Tree
English River at Kalona
Iowa River at Wapello
Iowa River at Columbus Junction
Cedar River at Charles City
Mississippi River at Burlington
Mississippi River at Gladstone IL
Upper Iowa River at Dorchester
Turkey River at Elkader
Turkey River at Garber
Little Sioux River at Linn Grove
Ocheyedan River near Spencer
Des Moines River at St. Francisville MO
Wapsipinicon River at Independence
Skunk River at Augusta
Wapsipinicon River at Anamosa
Nishnabotna River near Hamburg
Little Sioux River at Spencer
Little Sioux River near Milford
Big Sioux River at Hawarden
Des Moines River at Jackson MN
Little Sioux River at Cherokee
Big Sioux River at Akron
Wapsipinicon River near De Witt

Also to show how wide ranging the flooding is, the NWS in St Louis has issued a River Flood Warning for the entire Mississippi River from Chester IL northward to Canton MO (including at St Louis)
There is also River flood warnings along the Missouri River on the other side of the state south of the Iowa Missouri Border below Hamburg.

Ice Jams Causing Flash Flooding

iowawx — Sat, 13 Mar 2010 05:56:33 +0000

BULLETIN – EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1136 PM CST FRI MAR 12 2010

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR ICE JAM FLOODING IN…
CENTRAL WEBSTER COUNTY IN CENTRAL IOWA…

* UNTIL 530 AM CST

* AT 1135 PM CST…EMERGENCY MANAGEMENT REPORTED THAT FLASH FLOODING CONTINUED ALONG THE DES MOINES RIVER ON THE NORTH EDGE OF FORT DODGE…IN THE BREEN AND RIVERDALE ADDITIONS. WATER WAS SURROUNDING OR ENTERING HOMES IN THE BREEN ADDITION. PORTIONS OF ROADS NEAR THIS AREA OF THE RIVER WERE ALSO LIKELY UNDER WATER. THE WATER CONTINUED TO RISE SLOWLY. ROADS IN THE AREA ARE BARRICADED TO ALL WITH THE EXCEPTION OF LAW ENFORCEMENT AND HOME OWNERS.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE…FORT DODGE.

THIS WARNING EXTENDS THE FLASH FLOOD WARNING ISSUED FRIDAY EVENING.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. DO NOT ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

There is also a Flash Flood Warning in Cerro Gordo County, specifically in Mason City due to an ice jam along the Winneabago River there until 4:30am.

More Rain Tonight into Saturday

iowawx — Fri, 12 Mar 2010 20:03:28 +0000

Another batch of light to at times moderate rain will move into the state from the SE late tonight. This will mainly effect the eastern counties of the state while the rest of the state may see some drizzle or nothing at all.

Amounts will be light with many locations getting a quarter inch of rain or less. Even if the light amounts of rain, flooding is still going to be a concern this weekend and into next week with many of the state’s rivers running high if not over flood stage. Numerous rivers continue under flood warnings through next week.

After the storm moves away late on Saturday, skies will remain cloudy on Sunday, but will remain dry. Highs will be in the 40s and 50s, with lows in the 30s to around 40. The upcoming week looks to have some dry periods with a slight chance of precipitation on Tuesday. Another possible chance comes again next Friday.

River Flood Warnings as of Thursday

iowawx — Thu, 11 Mar 2010 19:44:26 +0000

River flooding continues across many of the rivers and streams in the state. Here is a list (LONG!) of the rivers that are currently under or have warnings issued into the future.

Chariton River near Chariton
Thompson River at Davis City
South Fork Chariton River near Promise City
Iowa River near Rowan
Beaver Creek at New Hartford
Winneabago River at Mason City
Shell Rock River at Shell Rock
Cedar River at Cedar Falls
Cedar River at Waterloo
Cedar River at Janesville
West Fork Cedar River at Finchford
Iowa River at Marshalltown
North River near Norwalk
Des Moines River at SE 6th (DSM)
North Raccoon River near Jefferson
Des Moines River near Stratford
Raccoon River at Fleur Dr. (DSM)
East Fork Des Moines River near Algona
Middle River near Indianola
Raccoon River at Van Meter
Raccoon River at IA Hwy 28
Beaver Creek near Grimes
Boone River near Webster City
Des Moines River at Fort Dodge
North Raccoon River near Perry
Des Moines River near Eddyville
Des Moines River at Humboldt
Des Moines River at Emmetsburg
Des Moines River at Estherville
Cedar Creek near Bussey
East Fork Des Moines River at Dakota City
South Skunk River at US Hwy 30 (Ames)
South Skunk River at Colfax
South Skunk River at Oskaloosa
Squaw Creek at Ames
Nishnabotna River near Hamburg
English River at Kalona
Skunk River at Augusta
North Skunk River near Sigourney
Iowa River near Lone Tree
Cedar River at Cedar Rapids
Iowa River at Wapello
Iowa River at Marengo
Des Moines River at St. Francisville MO
Cedar River near Conesville
Wapsipinicon River at Anamosa
Iowa River at Columbus Junction
Turkey River at Elkader
Turkey River at Garber
Upper Iowa River at Dorchester
Little Sioux River near Milford
Little Sioux River at Spencer
Little Sioux River at Linn Grove
East Fork Nishnabotna River at Red Oak
Wapsipinicon River at DeWitt

A Break but for How Long

iowawx — Thu, 11 Mar 2010 17:41:53 +0000

The low pressure center at midday was located west of Des Moines near Guthrie Center. It is easily denoted with a small batch of showers around the center. The rest of the state is mainly dry except in the far western parts of the state where cold air has begun to wrap into the storm. The rain has changed over to snow especially in Nebraska where a few inches fell in Omaha last night.

Temperatures are wide ranging from the 30s in western Iowa, to near 60 in the east where sunshine has broken out. There is a slight chance of a thunderstorm in the eastern counties early this afternoon before cooler rotates in from the SW. Another batch of rain is set to move in again on Friday.

AFD from the NWS Quad Cities This AM

iowawx — Thu, 11 Mar 2010 09:35:30 +0000

Here is a portion of the Area Forecast Discussion from the NWS in the Quad Cities, including a mention of “POSSIBLE” severe weather along the Mississippi River and into Illinois. NOTE: Most of this is very techinical!

.SHORT TERM…TODAY AND TONIGHT…
RAINFALL TODAY IS NO CERTAIN AS WE HAVE THE DRY SLOT MOVING IN AROUND 12Z IN THE NORTHWEST AND CENTRAL. THEREFORE THE WEST AND SOUTH MAY BE RAIN FREE THIS MORNING AND POSSIBLY THIS AFTERNOON…RESULTING IN A DRY AND BREEZY DAY. THE NORTH AND EAST SHOULD NOT SEE THE DRY SLOT UNTIL AFTER 14Z…AND ARE GOING TO NEED CATEGORICAL OR LIKELY POPS THIS MORNING. RAINFALL AMOUNTS SHOULD BE LIGHT SINCE PCPN IS MOVING SO FAST…AND CONVECTION IS FOUND IN SMALL CELLS WHICH DO NOT COVER MUCH TERRITORY UNDER THEM. IN OTHER WORDS…ANY HEAVY RAIN WILL BE BRIEF.

MORE OF A CONCERN TODAY WILL BE FOR SHALLOW MINI SUPERCELL THUNDERSTORMS DURING PEAK HEATING. THE OCCLUDED FRONT SHOULD BE WORKING THROUGH THE CWA DURING THE 18Z TO 21Z PERIOD…AND PRIOR TO THIS…THE DRY SLOT SHOULD HAVE POTENTIAL TO BRING ENOUGH SUN TO HEAT UP TEMPS INTO THE UPPER 50S TO LOWER 60S
ALONG AND EAST OF THE MISSISSIPPI RIVER. THE SHALLOW CAPE WILL HAVE SUFFICIENT SHEAR TO PRODUCE ROTATING UPDRAFTS…AND POSSIBLE HAIL AND ISOLATED TORNADOES. COVERAGE SHOULD BE LOW…AND CHANCE POPS AT MOST SEEM WARRANTED. WILL COVER THIS THREAT IN THE HWO TODAY…BUT IT SHOULD BE NOTED THAT THIS WILL BE A BRIEF WINDOW OF LOW COVERAGE STORMS IF IT OCCURS. OTHERWISE…TEMPS SHOULD BE SIMILAR TO
YESTERDAY TODAY…WITH MILD IN THE EAST AND SEASONALLY COOL IN THE WEST.

Area Forecast Discussion from NWS Des Moines This Morning

iowawx — Thu, 11 Mar 2010 09:31:05 +0000

Here is the hydrology portion of this morning’s Area Forecast Discussion from the NWS in Des Moines

WIDESPREAD FLOOD EVENT…DRIVEN BY COMBINATION OF RAPID SNOW MELT AS WELL AS OBSERVED AND FORECAST RAINFALL…IS ALREADY UNDERWAY OR WILL START WITHIN THE NEXT FEW DAYS…IN MOST LOCATIONS. WE/RE NOT LOOKING AT ANOTHER 2008 EVENT HOWEVER. THE FLOODING IS STARTING MAINLY FROM SOUTH TO NORTH. BASINS OF MOST CONCERN ARE FIRST THE DES MOINES/RACCOON…FOLLOWED BY THE CEDAR/IOWA THEN SKUNK. MODERATE TO MAJOR FLOODING EXPECTED AT MANY LOCATIONS IN THE DES MOINES/RACCOON RIVER BASINS.

AS MANY PEOPLE HAVE NOTICED…WE ISSUED OUR RIVER FLOOD WARNINGS MUCH FARTHER IN ADVANCE OF THE FLOODING THAN IS TYPICAL. THIS WAS DUE TO OUR HIGH CONFIDENCE IN THE FLOODING TO OCCUR. /NWS POLICY FOR RIVER FLOOD WARNINGS REQUIRES AT LEAST AN 80 PERCENT CONFIDENCE LEVEL IN RIVER FLOODING TO OCCUR. OUR CONFIDENCE IN THE FLOODING TO OCCUR WAS IN EXCESS OF 90 PERCENT…AND NEAR 100 PERCENT IN MOST LOCATIONS./ SEVERAL DAYS AGO OUR RIVER MODELS WERE SHOWING
SIGNIFICANT RISES ON MANY RIVERS OWING SOLELY TO SNOW MELT. EARLY THIS WEEK OUR CONFIDENCE BECAME HIGH IN MODERATE TO HEAVY RAINFALL AS WELL…SO WE ELECTED TO GET THE WORD OUT AS EARLY AS POSSIBLE.

ICE JAMS HAVE BEEN PROBLEMATIC SINCE LAST NIGHT…FIRST STARTING ON THE LOWER RACCOON RIVER AND HAS SINCE EXPANDED TO SEVERAL CREEKS AND SMALL STREAMS MAINLY FROM US HWY 30 SOUTHWARD. AREA OF PRIMARY CONCERN NOW IS SQUAW CREEK IN THE AMES AREA. THE CITY OF AMES ADVISES THAT THEIR CREWS HAVE BEEN WORKING…WITH LIMITED SUCCESS…TO MITIGATE THE ICE JAM THERE. THEY ARE CONCERNED ABOUT FLASH FLOODING POTENTIAL TONIGHT INTO TOMORROW…THUS WE ISSUED A FLASH FLOOD WATCH FOR THAT AREA.

ICE JAM CONCERNS WILL SHIFT NORTHWARD WITH TIME…OVER THE NEXT FEW DAYS. AFTER THE AMES AREA…ANOTHER PLACE OF CONCERN WILL BE ON THE DES MOINES RIVER IN THE FORT DODGE AREA. ICE JAMS THERE HISTORICALLY HAVE BEEN PROBLEMATIC…AND TEND TO OCCUR WITHIN A FEW DAYS OF ICE JAMS OCCURRING ON THE LOWER RACCOON RIVER IN THE DES MOINES AREA.

RIVER FORECASTS DO INCLUDE FCST PRECIP THRU SATURDAY MORNING. PER METEOROLOGICAL DISCUSSION ABOVE…WE MAY SEE ADDITIONAL SEASONALLY MODERATE RAINFALL THIS WEEKEND. OUR PRESENT THINKING IS THAT THIS ADDITIONAL RAINFALL WOULD EITHER RESULT IN CRESTS BEING REACHED MORE
QUICKLY…OR THE RIVERS FALLING MORE SLOWLY ONCE THEY DO CREST. WE DO NOT EXPECT THE RAIN TO ADD SIGNIFICANTLY TO THE CRESTS LIKE WHAT HAPPENED IN 2008 IN SOME LOCATIONS. WE WILL HAVE TO CONTINUE MONITORING THIS SITUATION.

Thunderstorms Moving into EC Iowa

iowawx — Thu, 11 Mar 2010 03:47:29 +0000

…SCATTERED THUNDERSTORMS WITH HEAVY RAIN AND SMALL HAIL…

SCATTERED THUNDERSTORMS WILL MOVE NORTHWARD ACROSS THE AREA THROUGH MIDNIGHT PRODUCING BRIEF HEAVY RAIN AND GUSTY WINDS UP TO 35 MPH. THE STRONGER STORMS COULD PRODUCE HAIL UP TO THE SIZE OF A PENNY. SINCE THE GROUND IS SATURATED…ANY RAIN THAT DOES OCCUR WILL GO STRAIGHT INTO RUNOFF…WHICH MAY LEAD TO SOME FLOODING OF LOW LYING AREAS AND LOCALIZED RISES ON AREA CREEKS AND STREAMS.

Thunderstorms Moving into SE Iowa

iowawx — Thu, 11 Mar 2010 02:06:12 +0000

From the NWS in the Quad Cities

SHOWERS AND SCATTERED THUNDERSTORMS WILL LIFT NORTH OVER THE AREA THROUGH 10 PM. THE STRONGEST THUNDERSTORMS WILL PRODUCE SMALL HAIL…AND HEAVY RAIN WITH BETWEEN A THIRD AND ONE HALF INCH OF RAIN POSSIBLE IN LESS THAN AN HOUR. THIS RAIN
WILL BE FALLING ON SATURATED GROUND AND WILL LIKELY GO INTO
RUNOFF… WHICH WILL RESULT IN FLOODING OF LOW LYING AND
POORLY DRAINED AREAS… AND PONDING OF WATER ON ROADWAYS. IN
ADDITION… RISES WILL OCCUR ON AREA CREEKS AND STREAMS.

Severe Weather is not likely with these storms as they push to the north and northeast.

River Flooding Continues

iowawx — Wed, 10 Mar 2010 20:56:44 +0000

With more rain on the way and continued snowmelt across the state, rivers are continuing to rise to near and slightly over flood stage. Here are the following rivers that are currently under river flood warnings. (It is a LONG list)

Chariton River near Chariton
South Fork Chariton River near Promise City
Boone River near Webster City
North Raccoon River near Jefferson
North Raccoon River near Perry
Raccoon River at Van Meter
Raccoon River at IA Hwy 28
Raccoon River at Fleur Drive (DSM)
North River near Norwalk
Middle River near Indianola
Des Moines River at Estherville
Des Moines River at Emmetsburg
East Fork Des Moines River near Algona
Des Moines River at Humboldt
Des Moines River at Fort Dodge
Des Moines River near Stratford
Des Moines River at SE 6th (DSM)
Des Moines River near Eddyville
Des Moines River at St. Francisville MO
Beaver Creek near Grimes
Cedar Creek near Bussey
Iowa River near Rowan
Iowa River at Marshalltown
Iowa River at Marengo
Iowa River near Lone Tree
Iowa River at Columbus Junction
Iowa River at Wapello
Winneabago River at Mason City
Shell Rock River at Shell Rock
West Fork Cedar River at Finchford
Beaver Creek at New Hartford
Cedar River at Janesville
Cedar River at Cedar Falls
Cedar River at Waterloo
Cedar River near Conesville
North Skunk River near Sigourney
Squaw Creek at Ames
South Skunk River near Ames (US Hwy 30)
South Skunk River at Colfax
South Skunk River near Oskaloosa
Skunk River at Augusta
Thompson River near Davis City
West Fork Nishnabotna River at Randolph
West Fork Nishnabotna River at Hancock
East Fork Nishnabotna River at Red Oak
Nishnabotna River near Hamburg
Maquoketa River at Manchester
Maquoketa River near Maquoketa
English River near Kalona
Wapsipinicon River near Anamosa
Wapsipinicion River near DeWitt
Turkey River at Garber
Turkey River at Elkader

Most of these rivers will only experience minor flooding, but some of them will rise to moderate and major flooding. This is all dependent on the amount of rain that the basins get through Saturday when the storm finally departs the state.