SHOULD MOVE TOWARDS EASTERN LAKE SUPERIOR TODAY BASED ON PRESSURE
FALLS AT 09Z. STRONG WARM ADVECTION AHEAD OF THE SYSTEM IS
PRODUCING A LARGE AREA OF SHOWERS AND THUNDERSTORMS WHICH WILL
MOVE ACROSS THE AREA TODAY. THE STEADY SHOWERS SHOULD BE OVER
AROUND MIDDAY BUT THERE IS ENOUGH INSTABILITY FOR SCATTERED
SURFACE BASED SHOWERS OR THUNDERSTORMS THROUGH LATE AFTERNOON.
DRIER AIR WILL ARRIVE TONIGHT AS THE SYSTEM DEPARTS BUT ANY
CLEARING WILL BE BRIEF. AN UPPER SYSTEM MOVING ACROSS THE CENTRAL
PLAINS AND AN ASSOCIATED INVERTED TROUGH WILL BRING INCREASING
CLOUDS LATE TONIGHT AND RAIN THURSDAY. THE SYSTEM IS A BIT FLATTER
THAN EARLIER MODEL RUNS SO THE BETTER RAINS WILL LIKELY BE
FURTHER SOUTH. CLOUDS AND RAIN SHOULD HOLD TEMPERATURES DOWN IN
THE 40S IN MOST PLACES THURSDAY.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY.
TWO SYSTEMS WILL AFFECT THE AREA DURING THE PERIOD. THE FIRST
SYSTEM WILL MOVE ACROSS THE WESTERN GREAT LAKES REGION THURSDAY
NIGHT INTO FRIDAY WITH SECOND WEAKER SYSTEM MOVING ACROSS THE
AREA ON SUNDAY.
MANY ISSUES TO DEAL WITH ON THE FIRST SYSTEM. THE MODELS HAVE
VARYING MODEL SOLUTIONS WITH RESPECT TO PRECIPITATION TOTALS FOR
THE 6 HOURLY PERIODS...ESPECIALLY LATE THURSDAY NIGHT AND FRIDAY.
MAIN PROBLEM WITH THE MODELS IS HOW THE HANDLE THE 500MB WAVE
AND HOW IT WILL AFFECT SPEED OF SYSTEM AND HOW MUCH SYSTEM
WILL DEEPEN. THE GFS IS QUICKER IN MOVING THE SYSTEM OUT WHILE THE
ECMWF IS ONE OF THE SLOWER SOLUTIONS WITH RAIN LINGERING INTO
FRIDAY MORNING/EARLY AFTERNOON. DAY SHIFT TRENDED TOWARD SLOWER
SOLUTION AND WILL FOLLOW FOR NOW. DID NOT WANT TO BUMP THE EAST
INTO THE LIKELY CATEGORY SINCE WRF/GFS WERE MOVING THE SYSTEM OUT
FAIRLY QUICKLY LATE THURSDAY NIGHT AND FRIDAY MORNING. GFS WOULD
BE MAINLY DRY WHILE THE WRF WOULD SUGGEST SCATTERED PRECIPITATION.
THE UKMET/ECMWF WERE WETTER SOLUTIONS WITH HEAVIER BAND OF
PRECIPITATION FURTHER NORTH AND WEST. THINK THE WRF/GFS MAY BE A
TAD TOO QUICK IN PULLING OUT THE HEAVIER PRECIPITATION...BUT ALSO
THINK UKMET/ECMWF ARE OVER DONE ON THE QPF FIELDS AND WHERE AXIS
OF HEAVIER PRECIPITATION WILL SET UP.
FOR NOW...THINK HEAVIEST PRECIPITATION SHOULD FALL ACROSS
WAUTOMA TO GREEN BAY AND THE FOX CITIES TO THE LAKESHORE REGION
WITH LIGHTER AMOUNTS TO THE NORTHWEST. CURRENT THOUGHTS ARE THAT
ANY ACCUMULATING SNOW NORTH AND WEST OF GREEN BAY AND THE FOX
CITIES SHOULD BE MINOR. IF THE HEAVIER QPF BAND DOES SHIFT A
LITTLE FURTHER NORTH AND A LITTLE COLDER AIR WORKS INTO THE NORTH
CENTRAL AND NORTHEAST WISCONSIN...THERE COULD BE A BAND OF
SEVERAL INCHES OF SNOW FROM NEAR WAUSAU TO ANTIGO TO MARINETTE.
THIS ASSUMES EVERYTHING WORKS OUT, HPC DID DEPICT A SMALL CHANCE
OF 4 INCHES OF SNOW ON THE DAY 2 SNOW OUTLOOK JUST NORTH AND WEST
OF GREEN BAY. DUE TO THE LOWER ELEVATION AND THERMAL PROFILES
ISSUES... DO NOT THINK GREEN BAY WOULD SEE MUCH IN SNOW UNLESS
STORM TRACK SHIFTS A LITTLE FURTHER SOUTH AND MORE COLD AIR
FILTERS INTO THE REGION.
AN UPPER LEVEL DISTURBANCE WILL SWING ACROSS THE REGION ON
SUNDAY...BRINGING A CHANCE OF SHOWERS TO THE REGION. FOR NOW...
I HAVE LEFT SUNDAY NIGHT DRY BUT LATER SHIFTS MAY NEED TO ADD
PRECIPITATION FOR THIS PERIOD.
ANOTHER SYSTEM WILL AFFECT THE AREA JUST BEYOND THE FORECAST
PERIOD. DO HAVE SILENT 20 POPS ON TUESDAY TO ACCOUNT FOR THE
FEATURE. TEMPERATURES SHOULD BE SLIGHTLY BELOW NORMAL ON FRIDAY
INTO THE WEEKEND...THEN TEMPERATURES SHOULD BE AT OR SLIGHTLY
ABOVE NORMAL FOR THE REMAINDER OF THE PERIOD.
&&
.AVIATION...TAFS ARE SOMEWHAT TRICKY THIS AFTERNOON. AN UPPER LEVEL SHORT
WAVE WAS MOVING OUT OF THE AREA TO THE NORTHEAST AT 17Z. A SURFACE
LOW WAS OVER EXTREME WESTERN UPPER MICHIGAN WITH A WARM FRONT THAT
EXTENDED SOUTHEAST...A COLD FRONT THAT EXTENDED TO THE SOUTHWEST
AND A SECOND COLD FRONT NORTHWEST OF THE FIRST. THE MAIN AREA OF
SHOWERS WAS MOVING OUT OF THE STATE...BUT THERE WAS A DEVELOPING
LINE OF CONVECTION FROM LANGLADE COUNTY SOUTHWEST TO WOOD COUNTY
AT 1730Z. MESOANALYSIS INDICATED VERY STEEP SURFACE TO 1.5 KM LAPSE
RATES IN WESTERN WISCONSIN...SOUTHEAST MINNESOTA AND NORTHERN
IOWA...SO MORE CONVECTION WOULD NOT BE SURPRISING BUT CHANCES FOR
ANYTHING AT ONE OF THE TAFS SITES IS NOT HIGH ENOUGH TO INCLUDE IN
THE TAFS.
ASIDE FROM PRECIPITATION CHANCES...CIGS RANGED FROM VFR IN THE
EAST AND SOUTH TO ISOLATED IFR IN NORTH CENTRAL WISCONSIN.
CONFIDENCE IN CLOUD FORECAST IS NOT VERY HIGH TODAY. MODELS AND
THE PREVIOUS FORECAST HAD CONDITIONS IMPROVING TO VFR OR NO CIG
THIS EVENING BUT THERE SEEM TO BE PLENTY OF LOWER CLOUDS...MVFR
CIGS...MOVING TOWARD THE AREA EARLY THIS AFTERNOON. WENT A LITTLE
MORE PESSIMISTIC WITH CIGS...BUT NOT A LOT. WINDS ARE ALSO A
CONCERN WITH SOUTH WINDS SHIFTING TO SOUTHWEST AND THEN WEST TODAY
BEFORE BECOMING NORTHWEST OVERNIGHT. 12Z MPX SOUNDING HAD
UNIDIRECTIONAL FLOW FROM SURFACE TO 1000FT AGL WHERE SPEEDS WERE
AROUND 35 KNOTS...SO AS WINDS SHIFT TO WEST AND LOW LEVEL LAPSE
RATES INCREASE EXPECT HIGHER GUSTS.
MG
&&
.MARINE...LOW PRES IS CST TO MOVE INTO NR SECTIONS OF THE GREAT
LKS AND BRING GUSTY SOUTHERLY WINDS TO THE AREA TODAY. A CDFNT WILL
SWEEP TOWARD LK MI LATE WED AFTERNOON AND BRING A WIND SHIFT TO
THE WEST WED EVENING...AND TO THE NORTH WED NIGHT. WINDS ARE
EXPECTED TO GRADUALLY SUBSIDE TONGT.
&&
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