March 3, 2011 Todd Shea Warning Coordination Meteorologist National Weather Service La Crosse, WI

Normal to above average threat for flooding on Wisconsin rivers / tributaries Normal to above average threat for flooding on Wisconsin rivers / tributaries Above to Much Above Risk on Mississippi River Above to Much Above Risk on Mississippi River Outline… Outline… Setting the Stage for Potential Flooding Setting the Stage for Potential Flooding 2011 Spring Flood Long Range Probabilistic Outlooks 2011 Spring Flood Long Range Probabilistic Outlooks Outlooks updated….today! Outlooks updated….today!

Past precipitation / Antecedent soil conditions Past precipitation / Antecedent soil conditions Snow pack / liquid equivalent Snow pack / liquid equivalent Frost depth Frost depth Freeze / melt cycle Freeze / melt cycle Future precipitation Future precipitation Time of melt Time of melt Ice conditions Ice conditions

Factor High Risk 2011 Past Precipitation Wet Snow Pack Deep / Wet Frost Depth Deep Melt Cycle Quick / Warm Future Precipitation Wet Time of Melt Late Ice Conditions Thick  ??? ??? ???

Sept.23, 2010 Rainfall September 2010 Precipitation

Fall 2010 Precipitation Fall 2010 Percent of Normal Precipitation

180 Day Precipitation Percent of Normal Precipitation

Most rivers above or much above normal Reservoirs and lowland areas are full. Reservoirs and lowland areas are full. River ice has efficiently formed. River ice has efficiently formed. Ice jams are possible. Ice jams are possible.

Stage on March 1 st / Spring Crest

TemperaturePrecipitation

TemperaturePrecipitation

TemperaturePrecipitation

Minor Flood

Moderate Flood

Major Flood

AHPS Webpages Soil Conditions Based on 3/3/11Soil Conditions Based on 3/3/11 Model run from 3/7/11 – 6/5/11Model run from 3/7/11 – 6/5/11 **60 year statistical analysis does not include 2009/2010 data.**60 year statistical analysis does not include 2009/2010 data.

Portage, WI Minor 95% (90%) - Minor Flood Stage Moderate 93% (72%) - Moderate Flood Stage Major 78% (50%) - Major Flood Stage **Percentages in parenthesis denote probabilistic outlooks from 2/17.

La Crosse, WI Minor >98% (>98%) - Minor Flood Stage Moderate >98% (95%) - Moderate Flood Stage Major 82% (59%) - Major Flood Stage **Percentages in parenthesis denote probabilistic outlooks from 2/17.

Outlook Locations Categorical Flood Stages (ft) Probability ofMinor Moderate Probability of Moderate Probability ofMajor Wisc. Rapids Wisconsin 12/13.5/15 9% (8%)3% (3%)-- (--) Portage Wisconsin 17/18/19 95% (90%)93% (72%)78% (50%) Berlin Fox 13/14.5/15.5 >98% (75%)83% (34%)49% (19%) Afton Rock 9/11.1/12.293% (83%)49% (39%)27% (18%) Newville Rock 10/11/11.526% (18%)1% (4%)1% (1%) **Percentages in parenthesis denote probabilistic outlooks from 2/17 Preliminary outlooks

Outlook Locations Categorical Flood Stages (ft) Probability ofMinor Moderate Probability of Moderate Probability ofMajor Black River Falls Black 47/51/55 95% (82%)80% (57%)26% (16%) La Farge Kickapoo 12/13/1463% (24%)42% (8%)8% (1%) Viola Kickapoo 14/17/20>98% (>98%)39% (13%)1% (--) Soldiers Grove Kickapoo 13/16/19>98% (86%)34% (9%)3% (1%) Steuben Kickapoo 12/13/15>98% (>98%)>98%(63%)16% (4%) **Percentages in parenthesis denote probabilistic outlooks from 2/17 Preliminary outlooks

Outlook Locations Categorical Flood Stages (ft) Probability ofMinor Moderate Probability of Moderate Probability ofMajor Red Wing Mississippi 14/15/16 >98% (>98%)>98% (95%)>98% (91%) Lake City Mississippi 16/18/20 >98% (95%)88% (80%)75% (50%) Wabasha Mississippi 12/14/16 >98% (>98%)>98% (93%)86% (73%) Winona Mississippi 13/15/18>98% (>98%)>98% (95%)88% (75%) La Crosse Mississippi 12/13/15.5>98% (>98%)>98% (95%)82% (59%) **Percentages in parenthesis denote probabilistic outlooks from 2/17 Preliminary outlooks

Outlook Locations Categorical Flood Stages (ft) Probability ofMinor Moderate Probability of Moderate Probability ofMajor Lansing Mississippi 18/19/20 88% (75%)83% (65%)78% (49%) McGregor Mississippi 16/20/23 >98% (>98%)>98% (88%)86% (67%) Guttenberg Mississippi 15/18/21 >98% (>98%)95% (83%)78% (47%) Dubuque Mississippi 17/18/21.5>98% (98%) 93% (78%) **Percentages in parenthesis denote probabilistic outlooks from 2/17 Preliminary outlooks

Outlook Locations Categorical Flood Stages (ft) Probability ofMinor Moderate Probability of Moderate Probability ofMajor Rock Springs Baraboo 18.5/21/23 >98% (83%)91% (57%)37% (21%) W. Baraboo Baraboo 9/10.5/15 50% (24%)27% (11%)4% (1%) Baraboo 16/22/23.1 >98% (83%)31% (18%)9% (8%) New Munster Fox 10/13/14>98% (96%)44% (42%)18% (18%) **Percentages in parenthesis denote probabilistic outlooks from 2/17 Preliminary outlooks

Outlook Locations Categorical Flood Stages (ft) Probability ofMinor Moderate Probability of Moderate Probability ofMajor Watertown Rock 5.5/6/6.5 60% (32%)32% (19%)23% (9%) Jefferson Rock 10/11/13 82% (60%)60% (39%)19% (11%) Ft. Atkinson Rock 6/7/8 73% (49%)45% (29%)1% (3%) Milford Crawfish 7/9/1063% (60%)26% (19%)8% (13%) **Percentages in parenthesis denote probabilistic outlooks from 2/17 Preliminary outlooks

Additional precipitation occurs prior to the melt? Additional precipitation occurs prior to the melt?

Type of Melt Type of Melt Slow (optimal)- little to no rain/snow and dryer Relative Humidity. temperatures – highs mid 30s to lower 40s, overnight lows 20’s(or colder) Rapid (increases flooding threat) Rain on snow increases melt rate and adds more water to the situation. Temperatures – Highs mid 40s and warmer, lows around 30 and warmer (Colder overnight lows slows down or shuts off the melting process) A delayed thaw increases the possibility of a faster melt and the likelihood that a rain on snow event would occur.

Location (lat and lon if available otherwise, general description, bridge, river, etc) Location (lat and lon if available otherwise, general description, bridge, river, etc) Duration if known Duration if known Is water rising behind the jam (quickly??) Is water rising behind the jam (quickly??) Is water moving around the sides of the jam? Is water moving around the sides of the jam? Is anything flooding/near to being flooded? Is anything flooding/near to being flooded? Is it a sheet of ice, lots of large ice chunks. Is it a sheet of ice, lots of large ice chunks. Is the ice moving, lifting, etc Is the ice moving, lifting, etc What infrastructure is immediately downstream? What infrastructure is immediately downstream? Estimate of the size or length of the jam. Estimate of the size or length of the jam. Ice Information to Report to the NWS

In addition to the traditional methods of NOAA Weather Radio, Internet, TV and Radio.

RSS (Really Simple Syndication) Feeds are sent for River Information including River Observations River Observations Issuance of River forecasts Issuance of River forecasts When Critical “alert” stages are exceeded or forecast When Critical “alert” stages are exceeded or forecast Main AHPS RSS feed page: Main NWS RSS feed page at:

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Minor to Moderate Flooding in some Wisconsin Rivers Minor to Moderate Flooding in some Wisconsin Rivers Moderate to Major Flooding certainly possible along Mississippi River Moderate to Major Flooding certainly possible along Mississippi River Optional Spring Flood Outlook: March 10th