From the NWS AFD 1/31/14
.HYDROLOGY...
CURRENT RIVER ICE CONDITIONS...
ALL RIVERS IN THE HSA REPORT AT LEAST SOME ICE COVER, WITH MANY COMPLETELY ICE COVERED. MANY GAGE READINGS SHOW ICE EFFECTS.
ICE JAMS...
SOLID ICE COVER IS NOT NECESSARILY AN ICE JAM. AN ICE JAM IS DEFINED AS A RESTRICTION. IF WATER IF FLOWING UNDERNEATH THE ICE, AND NOT CAUSING THE WATER TO BACK UP, THE ICE COVER IS NOT CONSIDERED A JAM.
ICE BREAK UP...
THE TWO MAIN FACTORS THAT QUICKLY CAUSE ICE TO BREAK UP ARE RUNOFF AND TEMPERATURES, WITH RUNOFF BEING A MORE SIGNIFICANT FACTOR. WHEN WATER LEVELS RISE, IT LIFTS THE ICE, FRACTURES IT, AND DISLODGES IT FROM THE RIVER BANKS. SO LET'S TAKE A LOOK AT TEMPERATURES AND RAINFALL(WHICH LEADS TO RUNOFF).
TEMPERATURES...
SATURDAY...LOWS IN THE 20S. HIGHS IN THE 40S.
SUNDAY...LOWS IN THE 30S. HIGHS IN THE 40S TO MID 50S.
MONDAY...LOWS IN THE HIGH TEENS TO AROUND 30. HIGHS IN THE UPPER 20S TO UPPER 30S.
TUESDAY...LOWS IN THE TEENS TO MID 20S. HIGHS IN THE 30S TO LOW 40S.
WEDNESDAY...LOWS IN THE MID 20S TO MID 30S. HIGHS IN THE 30S AND 40S.
RAINFALL...
THERE IS A CHANCE OF RAIN ACROSS PORTIONS OF THE HSA ON SATURDAY NIGHT AND SUNDAY, BUT THE QPF LOOKS TO BE LESS THAN A 0.10 OF AN INCH WHICH WOULD GENERATE LITTLE RUNOFF.
A HEAVIER RAINFALL IS EXPECTED SOMETIME NEXT TUESDAY OR WEDNESDAY (STARTING OFF AS SNOW AND ICE FOR THE NORTHERN HALF OF HSA). EARLY QPF VALUES LATE TUESDAY INTO WEDNESDAY ARE IN EXCESS OF 1.00 INCH WHICH WOULD CAUSE SIGNIFICANT RUNOFF.
FUTURE ICE CONDITIONS...
WHILE ICE RELEASES AND POSSIBLE JAMS ARE HARD TO PREDICT, WE FEEL WITHOUT ANY SIGNIFICANT RUNOFF THIS WEEKEND, THE WARMER DAYTIME TEMPERATURES ALONE WILL NOT BREAK UP THE ICE.
INSTEAD, WE FEEL THE ICE WILL SOFTEN AND MELT. AT THIS TIME, THERE IS MORE OF A CONCERN FOR THE MIDDLE OF NEXT WEEK AS DAYTIME HIGHS ARE FORECAST TO CLIMB ABOVE FREEZING AND A HEAVIER RAINFALL IS EXPECTED TO MOVE INTO THE AREA.
STILL, BECAUSE RIVER ICE IS UNPREDICTABLE, PLEASE CONTINUE TO MONITOR YOUR NEARBY STREAMS AND RIVERS AND NOTIFY THE APPROPRIATE PERSONNEL IF YOU SHOULD SEE ANY FLOODING AND/OR AN ICE JAM OCCURRING.
.HYDROLOGY...
CURRENT RIVER ICE CONDITIONS...
ALL RIVERS IN THE HSA REPORT AT LEAST SOME ICE COVER, WITH MANY COMPLETELY ICE COVERED. MANY GAGE READINGS SHOW ICE EFFECTS.
ICE JAMS...
SOLID ICE COVER IS NOT NECESSARILY AN ICE JAM. AN ICE JAM IS DEFINED AS A RESTRICTION. IF WATER IF FLOWING UNDERNEATH THE ICE, AND NOT CAUSING THE WATER TO BACK UP, THE ICE COVER IS NOT CONSIDERED A JAM.
ICE BREAK UP...
THE TWO MAIN FACTORS THAT QUICKLY CAUSE ICE TO BREAK UP ARE RUNOFF AND TEMPERATURES, WITH RUNOFF BEING A MORE SIGNIFICANT FACTOR. WHEN WATER LEVELS RISE, IT LIFTS THE ICE, FRACTURES IT, AND DISLODGES IT FROM THE RIVER BANKS. SO LET'S TAKE A LOOK AT TEMPERATURES AND RAINFALL(WHICH LEADS TO RUNOFF).
TEMPERATURES...
SATURDAY...LOWS IN THE 20S. HIGHS IN THE 40S.
SUNDAY...LOWS IN THE 30S. HIGHS IN THE 40S TO MID 50S.
MONDAY...LOWS IN THE HIGH TEENS TO AROUND 30. HIGHS IN THE UPPER 20S TO UPPER 30S.
TUESDAY...LOWS IN THE TEENS TO MID 20S. HIGHS IN THE 30S TO LOW 40S.
WEDNESDAY...LOWS IN THE MID 20S TO MID 30S. HIGHS IN THE 30S AND 40S.
RAINFALL...
THERE IS A CHANCE OF RAIN ACROSS PORTIONS OF THE HSA ON SATURDAY NIGHT AND SUNDAY, BUT THE QPF LOOKS TO BE LESS THAN A 0.10 OF AN INCH WHICH WOULD GENERATE LITTLE RUNOFF.
A HEAVIER RAINFALL IS EXPECTED SOMETIME NEXT TUESDAY OR WEDNESDAY (STARTING OFF AS SNOW AND ICE FOR THE NORTHERN HALF OF HSA). EARLY QPF VALUES LATE TUESDAY INTO WEDNESDAY ARE IN EXCESS OF 1.00 INCH WHICH WOULD CAUSE SIGNIFICANT RUNOFF.
FUTURE ICE CONDITIONS...
WHILE ICE RELEASES AND POSSIBLE JAMS ARE HARD TO PREDICT, WE FEEL WITHOUT ANY SIGNIFICANT RUNOFF THIS WEEKEND, THE WARMER DAYTIME TEMPERATURES ALONE WILL NOT BREAK UP THE ICE.
INSTEAD, WE FEEL THE ICE WILL SOFTEN AND MELT. AT THIS TIME, THERE IS MORE OF A CONCERN FOR THE MIDDLE OF NEXT WEEK AS DAYTIME HIGHS ARE FORECAST TO CLIMB ABOVE FREEZING AND A HEAVIER RAINFALL IS EXPECTED TO MOVE INTO THE AREA.
STILL, BECAUSE RIVER ICE IS UNPREDICTABLE, PLEASE CONTINUE TO MONITOR YOUR NEARBY STREAMS AND RIVERS AND NOTIFY THE APPROPRIATE PERSONNEL IF YOU SHOULD SEE ANY FLOODING AND/OR AN ICE JAM OCCURRING.