000
FXUS63 KAPX 031642
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1142 AM EST TUE MAR 3 2015

.UPDATE...
ISSUED AT 1142 AM EST TUE MAR 3 2015

NEXT CORRIDOR OF LIGHT TO MODERATE SNOWFALL (WARM ADVECTION AND
UPPER JET FORCED) NOW WORKING UP THROUGH NRN LOWER MICHIGAN INTO
EASTERN UPPER MICHIGAN. MADE SOME TWEAKS TO POPS/WEATHER TO HAVE
FLAT OUT CATEGORICAL POPS THROUGH MID AFTERNOON. THAT SAID...MID
LEVEL DRY SLOT ALREADY EVIDENT ON REGIONAL RADAR PLOT...ADVANCING
UP THROUGH SE WISCONSIN ACROSS SRN LAKE MICHIGAN. THIS WILL BRING
A SW-NE DIMINISHING TREND TO THE SNOWFALL THROUGH THE AFTERNOON
HOURS. BASED ON WHATS OCCURRED THUS FAR...AND RADAR TRENDS...SNOW
ACCUMULATION FORECASTS MAY BE JUST A LITTLE TOO HIGH (PARTICULARLY
THE SW COUNTIES)...AND MAY TRIM THOSE NUMBERS BACK JUST A BIT.

&&

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 315 AM EST TUE MAR 3 2015

SYNOPTIC PATTERN AND OBSERVATIONS:

EARLY THIS MORNING...SFC HIGH PRESSURE WAS EXITING OFF TO OUR EAST
WITH SHALLOW RIDGING IS OVERHEAD. ONE SHORTWAVE TROUGH WAS SEEN
DIGGING INTO THE DAKOTAS...WHILE A CLOSED LOW WAS NEAR SAN DIEGO. SW
FLOW STRETCHED FROM THIS CLOSED LOW INTO THE CENTRAL PLAINS AND FAR
WESTERN GREAT LAKES. EMBEDDED SHORTWAVES/VORTICITY MAXIMA WERE
BURIED WITHIN THIS MAIN CHANNEL OF UPPER LEVEL WINDS...WITH THE BEST
WAVE SEEN ENTERING WESTERN KS/NE...ASSOCIATED WITH SFC LOW PRESSURE.
A WARM FRONT EXTENDED EAST AND SE OF THIS LOW PRESSURE...INTO
MISSOURI. THIS IS ALSO WHERE THE GULF OF MEXICO TAP/BETTER LOW LEVEL
MOISTURE RESIDED...USHERED IN VIA 50-55KT LLJ. ACROSS OUR
REGION...THERE WAS AN ELEVATED WARM FRONT PUSHING UP INTO THE
WESTERN AND SOUTHERN GREAT LAKES...ON THE LEADING EDGE OF DEEP LAYER
WAA. MUCH OF THIS FORCING WAS BEING USED UP RIGHT NOW TO TRY AND
SATURATE A VERY DRY ATMOSPHERE (00Z APX SOUNDING 0.05" PWAT).
REGARDLESS...THERE WERE SOME SPOTS WHERE THE REGIONAL RADAR ECHOES
WERE REACHING GROUND...WITH LIGHT SNOW BEING REPORTED. THE BETTER
PRECIPITATION/SNOW WAS DEVELOPING ACROSS SOUTH DAKOTA WITHIN LEFT
EXIT REGION OF THE UPPER JET AND BEST DPVA...AND ALSO IN A SECONDARY
AREA OF UPPER DIVERGENCE IOWA/IL (THE LATTER ALSO BURIED MORE DEEPLY
IN THE WAA).

SKIES WERE CLEAR LAST EVENING AND TEMPERATURES...AS EXPECTED
PLUMMETED INTO THE SINGLE DIGITS BOTH ABOVE AND BELOW ZERO...BUT
THOSE READINGS WERE COMING UP WITH THE INFLUX OF DEEPER MID AND
UPPER LEVEL MOISTURE/CLOUDS.

SYNOPTIC PATTERN EVOLUTION AND ASSOCIATED WEATHER:

THE NRN STREAM WAVE WORKING INTO THE DAKOTAS WILL DIG FURTHER INTO
THE NC PLAINS AND NRN GREAT LAKES TODAY...WHILE THE BETTER
SHORTWAVE/VORTICITY MAXIMUM FROM WESTERN NE/KS LIFT UP TOWARD LAKES
SUPERIOR/MICHIGAN. THIS RESULTS IN A TIGHTENED MID AND UPPER LEVEL
FLOW...AND SUBSEQUENT UPPER JET STRENGTHENING AS IT WORKS IN OVER
LOWER MICHIGAN LATER TODAY...BEFORE ULTIMATELY LAYING OUT OVERHEAD
TONIGHT. THE SFC LOW IS EXPECTED TO LIFT THROUGH NRN LOWER MICHIGAN
BUT BECOME LOST IN THE MAIN SFC LOW CIRCULATION WHICH WILL BE IN
ONTARIO. DEEP LAYER WAA WORKS IN OVER MAINLY LOWER MICHIGAN...STILL
TRYING TO SATURATE THE ATMOSPHERE...USING UP SOME FORCING TO DO
SO...BUT WILL GET HELP FROM MORE RAPIDLY NORTHWARD ADVANCING GULF
MOISTURE. THE STRONGEST FORCING IS REALLY GOING TO WIND UP BEING
TIED TO DPVA AND UPPER DIVERGENCE WHICH JUST STRENGTHEN WITH TIME
ALONG WITH THE UPPER JET. THE LEFT EXIT REGION WORKS IN ACROSS FAR
NW LOWER AND MAINLY EASTERN UPPER. THIS IS ALSO WHERE THE COLDEST OF
AIR AND HIGHER SNOW RATIOS WILL RESIDE....WITH A WETTER SNOW
EXPECTED ACROSS THE SE CWA.

WHILE SOME LIGHT SNOW WILL BE POSSIBLE AFTER DAYBREAK WITH THE
ELEVATED WARM FRONT...THE BETTER SNOWS WILL CONTINUE TO FILL IN WITH
INCREASING FORCING AND MOISTURE THROUGH DAYBREAK IN AREAS TO OUR
WEST AND SW. THESE MORE WIDESPREAD SNOWS WILL WORK INTO THE REGION
AS THE MORNING WEARS ON...AND CONTINUE INTO THE AFTERNOON. THE BEST
TIME FOR THE HEAVIER SNOW WILL PRIMARILY AFFECT THE REGION BETWEEN
17Z AND 21Z. THE MAIN FORCING WILL DEPART DURING THE MID AND LATE
AFTERNOON...WITH THE PASSAGE OF THE SYSTEM COLD FRONT AND ARRIVAL OF
THE UPPER JET. AT THIS POINT...THE MID AND UPPER LEVEL MOISTURE WILL
STRIP OUT...AND WE WILL SEE A RELATIVELY BRIEF PERIOD OF LIGHTER
SNOWS MIXING WITH OR CHANGING OVER TO FREEZING DRIZZLE. THE FREEZING
DRIZZLE WILL MAINLY BE ALONG AND SOUTH OF A LINE FROM FRANKFORT TO
GAYLORD AND ALPENA. MOISTURE CONTINUES TO FALL OFF INTO THE NIGHT
WITH SKIES MAYBE EVEN TRYING TO CLEAR IN SPOTS. PRECIPITATION WILL
END IN ALL AREAS FOR THE MID TO LATE EVENING. NO MUCH EXCITEMENT
OVERNIGHT...COLDER AIR DOES WORK INTO THE REGION FOR LAKE
EFFECT...BUT ALL OF THIS MOISTURE WILL BE RATHER SHALLOW AT THIS
POINT...SO ANY LAKE EFFECT WILL BE VERY MINIMAL. WILL ONLY GO WITH A
SMALL CHANCE IN THE WNW/NW FLOW REGIMES.

ALL-IN-ALL...THE ONGOING ADVISORY LOOKS SOLID. CAN SEE 4-5" ACROSS
EASTERN UPPER...RANGING TO 1-3" NEARER THE SAGINAW BAY TODAY WHERE
THE TOTAL FORCING IS LESS AND SNOW RATIOS LOWER.

HIGHS TODAY WILL BE IN THE MIDDLE 20S TO LOWER 30S. LOWS TONIGHT IN
THE COLD ADVECTION BEHIND THE FRONT...WILL REACH MORE OF THE ARCTIC
TYPE...4-8F IN EASTERN UPPER...TO THE TEENS NEAR THE SAGINAW BAY.

&&

.SHORT TERM...(WEDNESDAY THROUGH THURSDAY NIGHT)
ISSUED AT 315 AM EST TUE MAR 3 2015

...MORE ARCTIC COLD FOLLOWED BY WARMING...

AN ARCTIC FRONT WILL MOVE THROUGH THE AREA EARLY WEDNESDAY RESULTING
IN ANOTHER ROUND OF VERY CHILLY TEMPERATURES. LUCKILY THE COLD AIR
WILL BE RATHER SHORT LIVED AND BE GONE BY FRIDAY AFTERNOON DUE TO A
PROGRESSIVE AND MUCH LESS AMPLIFIED FLOW (FINALLY). THERE COULD BE A
FEW SNOW SHOWERS OR FLURRIES WEDNESDAY AS ENERGY DROPS DOWN THROUGH
THE FLOW (ESPECIALLY IN THE AFTERNOON) WITH LIMITED ACTIVATION OF
THE FROZEN OVER LAKES IN NORTHWEST FLOW. UPPER LEVEL TROUGHING HOLDS
THROUGH WEDNESDAY NIGHT YIELDING LIGHT NORTH NORTHWEST FLOW LAKE
EFFECT SNOW SHOWER CHANCES. HIGH PRESSURE CENTERED OFF TO OUR SOUTH
SHOULD THEN END ANY LAKE EFFECT NONSENSE THURSDAY MORNING. A
NORTHERN STREAM TROUGH WILL BRING SMALL CHANCES FOR SNOW SHOWERS IN
ON FRIDAY AS WELL. HIGHS ONLY IN THE UPPER SINGLE DIGITS TO THE
TEENS WEDNESDAY (WITH SLOWLY FALLING TEMPERATURES THROUGH THE DAY
DUE TO STRONG COLD ADVECTION). HIGHS THURSDAY IN THE LOWER AND
MIDDLE TEENS FOLLOWED BY HIGHS IN THE MIDDLE AND UPPER 20S FRIDAY.
LOWS IN THE SINGLE DIGITS BELOW ZERO FOR THE MOST PART FOR BOTH
WEDNESDAY AND THURSDAY NIGHTS (PERHAPS EVEN A FEW NEGATIVE TEENS
BELOW WEDNESDAY NIGHT). IN ADDITION...THERE WILL LIKELY BE LOW WIND
CHILL TEMPERATURES ON THE ORDER OF 10 TO 20 BELOW DUE TO BRISK WINDS
FROM WEDNESDAY NIGHT INTO EARLY THURSDAY AND AGAIN THURSDAY NIGHT
INTO EARLY FRIDAY.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 315 AM EST TUE MAR 3 2015

...MUCH MORE TOLERABLE TEMPERATURES...

A VERY PROGRESSIVE AND LESS AMPLIFIED PATTERN ALOFT WILL LEAD TO
MILDER READINGS OVER THE WEEKEND INTO THE BEGINNING OF NEXT WEEK.
THE COMBINATION OF ALTERNATING BOUTS OF WARM ADVECTION AND SHORT
WAVE ENERGY DROPPING DOWN THROUGH THE FLOW WILL BRING CHANCES FOR
SNOW SHOWERS BUT REALLY NOT A WHOLE LOT OF PRECIPITATION IS
EXPECTED. FORECAST HIGHS WILL BE IN THE UPPER 20S TO MIDDLE 30S
THROUGH THE PERIOD. LOWS MAINLY IN THE TEENS...THOUGH SOME SPOTS MAY
DROP INTO THE SINGLE DIGITS ABOVE ZERO SATURDAY NIGHT. LOOKING
FARTHER OUT INTO THE EXTENDED...IT LOOKS WARM...LIKE 50S WARM (MAYBE
EVEN WARMER) BY THE END OF NEXT WEEK AS THE RIDGE FINALLY MIGRATES
TO THE EAST (STAY TUNED PEOPLE...HOPE IS ON THE HORIZON).

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 633 AM EST TUE MAR 3 2015

...RAPIDLY DETERIORATING CONDITIONS...

LOW PRESSURE WILL PUSH INTO THE MISSISSIPPI VALLEY THEN NRN
MICHIGAN LATE TODAY. THE ASSOCIATED COLD FRONT PASSES LATE IN THE
AFTERNOON WITH MUCH DRIER AIR STARTING TO FILTER IN OVER THE AREA.
MUCH COLDER AIR THEN POURS INTO NRN MICHIGAN THROUGH THE NIGHT.

AHEAD OF THE LOW PRESSURE...A BAND OF SNOW HAS ALREADY DEVELOPED
AND WAS MOVING NORTH TOWARD PLN/APN...AFFECTING THEM 12-14Z. SNOWS
WILL FILL IN ACROSS TVC/MBL BY MID MORNING...AND BECOME HEAVIER
BY MIDDAY AND INTO THE EARLY AFTERNOON. THIS SNOW WILL DEVELOP
ACROSS PLN/APN A BIT LATER. THE HIGHEST SNOWFALL RATES AND MAIN
ACCUMULATIONS OF SNOW WILL BE BETWEEN 16Z-21Z...WITH RATES AS
HIGH AS AN INCH PER HOUR AT TIMES...IF NOT A LITTLE HIGHER. TOTAL
SNOWFALL WILL BE 3-4". THE SNOW MAY END AS A BIT OF FREEZING
DRIZZLE FOR ALL BUT PLN. ALL PRECIPITATION WILL LIKELY COME TO AN
END LATE INTO THE AFTERNOON/EARLY EVENING. VERY LITTLE IN THE WAY
OF LAKE EFFECT IS EXPECTED OVERNIGHT...AS MOISTURE WILL BE
DIFFICULT TO COME BY. BEST SHOT AT SOME LIGHT SNOW SHOWERS WILL BE
ACROSS TVC/MBL.

WINDS WILL BE OUT OF THE S/SE AND AOB 10KTS AHEAD OF THE COLD
FRONT...FOR MOST OF THE DAY...THEN VEER MORE W/NW WITH THE PASSAGE
OF THE FRONT. GUSTS ARE ALSO POSSIBLE OVERNIGHT...INTO THE TEENS.
WHILE WINDS ARE WEAKER TODAY...WINDS WILL BE REALLY INCREASING JUST
ABOVE THE SFC...AND LLWS NEEDED TO BE INTRODUCED INTO THE FORECAST.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ008-
     015>036-041-042.

LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

UPDATE...ADAM
NEAR TERM...SMD
SHORT TERM...SULLIVAN
LONG TERM...SULLIVAN
AVIATION...SMD