Quantitative Precipitation Forecast
Issued by NWS

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000
FOUS11 KWBC 160716
QPFHSD

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
316 AM EDT WED APR 16 2014

VALID 12Z WED APR 16 2014 - 12Z SAT APR 19 2014


DAY 1 TO DAY 2...

...UPPER MISSISSIPPI VALLEY/GREAT LAKES...

HEAVY SNOW IS EXPECTED TO DEVELOP DURING THE MORNING OVER
NORTHEASTERN SOUTH DAKOTA/CENTRAL MINNESOTA ACROSS NORTHERN
WISCONSIN INTO THE WESTERN HALF OF THE UPPER PENINSULA OF
MICHIGAN. THE AREA OF HEAVY SNOW IS EXPECTED TO DEVELOP WITH A
COUPLED JET PATTERN...WITHIN THE ENTRANCE REGION OF AN AMPLIFYING
300 MB 130 KT JET OVER THE UPPER LAKES WITHIN A PRONOUNCED
CONFLUENT REGION ON WEDNESDAY...AS WELL AS THE EXIT REGION OF A 90
KT 300 MB JET AT THE BASE OF A SHORTWAVE TROUGH MOVING EASTWARD
FROM NEBRASKA BY WEDNESDAY EVENING.  THE ENSUING SNOW BAND
DEVELOPS WITHIN A STRONG FRONTOGENETIC BAROCLINIC ZONE WITH STRONG
850 MB 50 KT JET DIRECTED TOWARD THE HEAVIEST SNOW.  EVEN THOUGH
THE SHORTWAVE MOVING EASTWARD APPEARS TO DE AMPLIFY AS IT
ENCOUNTERS THE HIGHLY CONFLUENT FLOW PATTERN...AS WELL AS THE
ASSOCIATED SURFACE LOW WEAKENS AS WELL...QPF AMOUNTS AREA QUITE
HIGH RESULTING IN A HIGH PROBABILITY OF 8 TO 12 INCHES OF SNOW
ACROSS NORTHERN WISCONSIN INTO NW MICHIGAN`S UPPER PENINSULA WITH
AT LEAST A MODERATE PROBABILITY OF GREATER THAN A FOOT OF SNOW.
SOME OF THIS REGION REPORTED SUBZERO TEMPERATURES ON TUESDAY
MORNING...WITH SIMILAR TEMPERATURES SHOWING SIMILAR TEMPERATURES
BEFORE CLOUDS MOVE IN BY MORNING.  SO MUCH FOR SPRING.

IN GENERAL...THE FORECASTS FOLLOWED A COMBINATION OF THE 00Z
NAM/00Z AND 12Z ECMWF AS WELL AS THE 15Z AND 21Z SREFMEANS WITH
VERY GOOD AGREEMENT ON HIGH QPF TOTALS FROM MANY SEPARATE RUNS.
THE LOW PRESSURE SYSTEM SHOULD CONTINUE TO WEAKEN AS IT SLOWLY
CROSSES THE UPPER MIDWEST ON THURSDAY...WITH SNOWFALL CONTINUING
BUT BECOMING LIGHTER ACROSS THE UPPER MIDWEST.

...CENTRAL/SOUTHERN ROCKIES...

A SEPARATE SHORT WAVE CROSSING THE SOUTHERN ROCKIES WILL PROVIDE
THE ASCENT FOR SNOWFALL ACROSS THE CENTRAL AND SOUTHERN
ROCKIES...WITH A MODEL CONSENSUS FOR THE HEAVIEST SNOW OCCURRING
ACROSS THE EASTERN SLOPES OF THE CENTRAL AND SOUTHERN COLORADO
ROCKIES/SAN JUAN RANGES. AS COLDER AIR MOVES SOUTHWARD ALONG THE
EASTERN SLOPES LATER WEDNESDAY INTO WEDNESDAY NIGHT...A STRONG
UPSLOPE COMPONENT TO THE FLOW WILL DEVELOP WITHIN THE ENTRANCE
REGION OF THE JET OVER THE CENTRAL PLAINS. MOST OF THE HEAVIER
SNOWFALL AMOUNTS WILL BE WITHIN THE 4 TO 8 INCH RANGE WITH A
RELATIVELY LOW POTENTIAL FOR GREATER THAN 8 INCHES OF SNOW WITH A
FOOT OR MORE POSSIBLE NEAR PIKES PEAK.

THE PROBABILITY FOR SIGNIFICANT ICING IS 10 PERCENT OR LESS ON ALL
THREE DAYS.

KOCIN


$$





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