000
FXUS63 KAPX 112313
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
713 PM EDT TUE MAR 11 2014

.SYNOPSIS...
ISSUED AT 429 PM EDT TUE MAR 11 2014

TEMPERATURES WILL TURN WELL BELOW AVERAGE FOR WEDNESDAY AND
THURSDAY. A STRONG STORM SYSTEM WILL PASS TO THE SOUTH OF NORTHERN
MICHIGAN WEDNESDAY...KEEPING THE AREA MAINLY DRY. THE NEXT CLIPPER
SYSTEM WILL BRING WARMER TEMPERATURES TO THE AREA FOR FRIDAY...ALONG
WITH THE NEXT CHANCE OF PRECIPITATION. COOLER WEATHER IS EXPECTED
ONCE AGAIN FOR THIS WEEKEND.

&&

.UPDATE...
ISSUED AT 713 PM EDT TUE MAR 11 2014

CLOUDY SKIES...MAINLY MID/HIGH CLOUDS...CONTINUE TO HANG OVER OUR
ENTIRE CWA THIS EVENING ALONG THE NRN PERIPHERY OF THE MOISTURE
SHIELD ASSOCIATED WITH DEVELOPING LOW PRESSURE OVER THE MID
MISSISSIPPI VALLEY. STILL APPEARS ALL PRECIP ASSOCIATED WITH THIS
SYSTEM WILL STAY SOUTH OF OUR CWA...WITH ONLY PERSIST MID/HIGH
CLOUDS HOLDING OVER THE REGION THRU THE NIGHT. NO ADJUSTMENTS
NEEDED TO GOING FORECAST. DO EXPECT FAIRLY RAPID CAA THRU THE
NIGHT AS THERMAL GRADIENT OVERHEAD TIGHTENS BETWEEN COLD CANADIAN
HIGH PRESSURE TO THE NORTH AND DEEPENING LOW PRESSURE TRACKING
THRU THE OHIO VALLEY.

&&

.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 429 PM EDT TUE MAR 11 2014

SURE HOPE YOU HAD A CHANCE TO ENJOY THE WARMTH OF THE LAST FEW
DAYS...CAUSE THINGS ARE GOING TO CHANGE IN A BIG HURRY STARTING
TONIGHT. FEATURES DRIVING THIS UNFORTUNATE CHANGE OF EVENTS ALREADY
ON THE TABLE...WITH DIGGING NORTHERN STREAM ENERGY DIVING SOUTHEAST
ACROSS THE PRAIRIE LANDS OF CANADA...ALL THE WHILE STRONG SHORTWAVE
ROTATES OUT OF THE WYOMING AND COLORADO. THESE TWO SYSTEMS
WILL HELP DRIVE THE DEVELOPMENT OF SIGNIFICANT OHIO VALLEY LOW
PRESSURE LATER TONIGHT. COMBINATION OF THIS SYSTEM AND HIGH PRESSURE
BUILDING SOUTH OUT OF CANADA WILL INDUCE SIGNIFICANT NORTH FLOW CAA
OVERNIGHT. FORECAST CHALLENGES CENTER ON THIS DOWNWARD TEMPERATURE
SPIRAL AND SOME LIGHT SNOW POTENTIAL.

INITIAL FGEN DRIVING BAND OF LIGHT SNOW/RAIN LOOKS TO LARGELY SLIDE
OFF TO OUR SOUTH THIS EVENING...WITH DEEP LAYER LOW LEVEL DRY WEDGE
LIKELY KEEPING ANY ELEVATED PRECIP FROM REACHING THE SURFACE OVER
OUR CWA. ATTENTION LATER TONIGHT TURNS TO STRONG DEFORMATION/FGEN
DYNAMICS IN RESPONSE TO DEEPENING OHIO VALLEY SYSTEM. CORE OF THESE
DYNAMICS NO DOUBT MISSES US TO OUR SOUTH...AND WITH LOW/MID LEVEL
DRY WEDGE FAILING TO COMPLETELY ERODE...SIMPLY DO NOT SEE GOOD SNOWS
REACHING THIS FAR NORTH. WILL MAINTAIN SOME LOW END POPS DOWN NEAR
SAGINAW BAY LATER TONIGHT TO ACCOUNT FOR ANY MINOR NORTHWARD TREND.
SLUG OF LOW LEVEL MOISTURE OFF TO OUR NORTHEAST LOOKS TO GET
CAPTURED IN DEVELOPING NORTH/NORTHEAST FLOW AROUND THIS LOW...AND
COMBINED WITH SOME OPEN POCKETS OF WATER ON LAKE HURON...SHOULD BE
ENOUGH TO KICK OFF SCATTERED/NUMEROUS FLURRIES OVER THE CENTRAL AND
NORTHEAST PORTIONS OF NORTHERN LOWER MICHIGAN TONIGHT. NO BIG DEAL
FOR SURE. NOW...THOSE TEMPERATURES ARE A WHOLE OTHER STORY. WHILE
DELAYED...STRONG CAA WILL NOT BE DENIED...DRIVEN SOUTH BY
TIGHTENING OVERHEAD PRESSURE GRADIENT. INCREASINGLY GUSTY NORTH
WINDS TONIGHT WILL REALLY SET THE TEMPERATURE PLUNGE IN
MOTION...WITH LOWS BY SUNRISE WEDNESDAY RANGING FROM THE SINGLE
DIGITS EASTERN UPPER...TO RIGHT AROUND 20 FAR SOUTHEAST. THIS WILL
SET THE STAGE FOR JUST DOWNRIGHT COLD MID MARCH CONDITIONS
WEDNESDAY. SEE LONG TERM DISCUSSION BELOW FOR MORE ON THAT BIT OF
EXCELLENT NEWS (ALONG WITH A BUNCH OF OTHER GOOD STUFF).

.LONG TERM...(WEDNESDAY THROUGH TUESDAY)
ISSUED AT 429 PM EDT TUE MAR 11 2014

...UP AND DOWN TEMPERATURES INTO THE WEEKEND...

HIGH IMPACT WEATHER POTENTIAL: BITTER COLD THURSDAY MORNING.

PATTERN SYNOPSIS/FORECAST: BROAD LONG WAVE TROUGH DOMINATES MUCH OF
THE WESTERN HEMISPHERE...PART OF A FOUR WAVE HEMISPHERIC PATTERN
THAT CONTAINS THREE SMALLER WAVELENGTH LONG WAVE TROUGHS OVER THE
EASTERN HEMISPHERE.  PHASING SHORT WAVE TROUGHS OVER THE CENTRAL
CONUS OVER THE COMING DAYS WILL AMPLIFY THE PATTERN OVER THE GREAT
LAKES AND ALLOW ANOTHER INTRUSION OF COLD AIR INTO NORTHERN MICHIGAN
THROUGH MIDWEEK.  ADDITIONAL SHORT WAVE ENERGY COMING IN FROM THE
PACIFIC BASIN WILL HELP REINFORCE THIS TROUGHING HEADING INTO THE
WEEKEND...SO A PERIOD OF ROLLER COASTER TEMPERATURES IN THE OFFING
THROUGH THE REMAINDER OF THE WEEK.

UPPER LEVEL FLOW PRETTY MUCH SPLIT INTO THREE BRANCHES...WITH A
SHORT WAVE TROUGH OVER THE WESTERN GULF IN THE SOUTHERNMOST
BRANCH...A SECOND WAVE MOVING OUT OF THE GREAT BASIN AND INTO THE
CENTRAL ROCKIES...AND IN THE NORTHERNMOST BRANCH A LARGER
WAVELENGTH TROUGH DIGGING ACROSS CENTRAL CANADA. SURFACE ANALYSIS
SHOWS A COLD FRONT ASSOCIATED WITH THE CANADIAN UPPER WAVE JUST
PUSHING INTO LAKE SUPERIOR WITH TEMPERATURES IN THE SINGLE DIGITS
AND TEENS BEHIND IT. 995MB SURFACE LOW OVER CENTRAL KANSAS WITH AN
EASTWARD EXTENDING STATIONARY FRONT INTO THE OHIO VALLEY...
PRECIPITATION TRYING TO BREAK OUT NORTH OF THIS BOUNDARY OVER THE
NORTHERN PLAINS/UPPER MIDWEST BUT LOW LEVEL MOIST INFLOW IS
LACKING INITIALLY.

KANSAS SURFACE LOW WILL TRACK TOWARD THE OHIO RIVER TONIGHT AS
NORTHERN AND MIDDLE BRANCH SHORT WAVE TROUGHS COME INTO PHASE ON
WEDNESDAY.  THIS WILL RAMP UP THE SURFACE SYSTEM AND BRING A
SIGNIFICANT WINTER STORM TO POINTS SOUTH AND EAST OF NORTHERN
MICHIGAN.  BUT THIS SYSTEM WILL HELP PULL COLDER AIR INTO MICHIGAN
FOR WEDNESDAY...WITH SURFACE RIDGE AXIS BUILDING INTO THE UPPER
GREAT LAKES THURSDAY FOLLOWED BY WARM ADVECTION AHEAD OF AN ALBERTA
CLIPPER THAT MAKES ITS WAY INTO THE REGION FRIDAY.

PRIMARY FORECAST CONCERNS (NEAR TERM): NORTHERN EXTENT OF PRECIPITATION
SHIELD ASSOCIATED WITH DEVELOPING WINTER STORM WEDNESDAY MORNING...
THURSDAY MORNING COLD...AND IMPACTS OF DEVELOPING WARM ADVECTION
PATTERN THURSDAY NIGHT.

NEAR TERM (WEDNESDAY/THURSDAY)...CURRENT EXPECTATION IS THAT NORTHERN
FRINGES OF SYNOPTIC SNOW SHIELD WILL CLIP FAR SOUTHEAST PORTIONS
OF THE FORECAST AREA WEDNESDAY MORNING...POSSIBLY SOME FLURRIES
COMING IN OFF LAKE HURON AND INTO NORTHEAST LOWER THROUGH THE DAY
(AND POSSIBLY INTO THE EVENING HOURS). DRIER AIR WILL BE ADVECTING
IN FROM THE NORTH DURING THE DAY...AND OUTSIDE OF LAKE CLOUDS/
FLURRIES EXPECTING SOME SUNSHINE ACROSS EASTERN UPPER/NORTHWEST
LOWER. NORTH WINDS WILL BE GUSTY WEDNESDAY AFTERNOON WITH COLD
ADVECTION ENHANCING MIXING...WITH GUSTS 20 TO 30 MPH EXPECTED.
STEADY OR SLOWLY FALLING TEMPERATURES EXPECTED DURING THE DAY WITH
THE WINDS PUSHING WIND CHILLS BELOW ZERO. CLEARING TREND INTO
WEDNESDAY NIGHT WITH LOW LEVEL RIDGING/ ANTICYCLONIC FLOW...AND
WITH WINDS DECOUPLING AFTER MIDNIGHT EXPECTED TO ALLOW
TEMPERATURES TO DROP WELL BELOW ZERO BY THURSDAY MORNING.

AS THE SURFACE RIDGE SLIDES EAST THURSDAY LOW/MID LEVEL WARM
ADVECTION WILL DEVELOP ACROSS MICHIGAN/WISCONSIN.  SHOULD BE A
MAINLY QUIET DAY WITH INCREASING MID/HIGH CLOUDS ADVANCING INTO THE
FORECAST AREA AS THE DAY WEARS ON.  NOT CERTAIN ABOUT INTRODUCING
PRECIPITATION CHANCES DURING THE DAYLIGHT HOURS...WILL HOLD OFF
UNTIL THURSDAY NIGHT AS CLIPPER DROPS IN FROM THE NORTHWEST WITH
SOME UNCERTAINTY IN EXACT TRACK OF THIS SYSTEM.  WILL CARRY CHANCE
POPS FOR SNOW ACROSS EASTERN UPPER/FAR NORTHERN LOWER.  GFS TRYING
TO IMPLY SOME LOW CLOUD/FREEZING DRIZZLE POTENTIAL THURSDAY NIGHT
BUT NOT INTERESTED IN JUMPING ON THIS IDEA YET (TENDENCY FOR THIS
IDEA TO BE OVERDONE...BETTER TO WATCH TRENDS IN LATER RUNS).

MEDIUM RANGE (FRIDAY/SATURDAY/SUNDAY)...CLIPPER SLIDES BY ON FRIDAY
ACROSS UPPER MICHIGAN/LAKE SUPERIOR...WHICH BRINGS A REINFORCING
PUSH OF COLDER AIR FOR THE WEEKEND.  COLD HIGH PRESSURE BUILDS IN
FOR SUNDAY.

SPECIFICS: CONTINUED CHANCES FOR SNOW NORTH ON FRIDAY WITH PASSING
CLIPPER...THEN MAINLY DRY FOR THE WEEKEND THOUGH WILL NEED TO EVALUATE
AND LAKE SNOW POTENTIAL VERSUS GREAT LAKES ICE COVER. COLD OVERNIGHT
LOW TEMPERATURES EXPECTED BOTH SUNDAY AND MONDAY MORNINGS.

OUTLOOK (MONDAY/TUESDAY)...COLD START MONDAY...UNCERTAINTY REGARDING
EVOLUTION OF SURFACE HIGHS AND RE-DEVELOPMENT OF WARM ADVECTION AND
RESULTANT PRECIP CHANCES EARLY NEXT WEEK.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 713 PM EDT TUE MAR 11 2014

VFR CONDITIONS WILL PERSIST ACROSS ALL NRN LWR MICHIGAN TAF SITES
THRU 00Z THURSDAY. ALL PRECIP AND SUB-VFR CONDITIONS WILL REMAIN
SOUTH OF OUR AREA...WITH THE EXCEPTION OF A FEW FLURRIES POSSIBLE
AROUND APN LATE TONIGHT AND WEDNESDAY. NORTH WINDS AT 10 TO 15 KTS
TONIGHT WILL STRENGTHEN ON WEDNESDAY...WITH GUSTS TO 30 KTS
EXPECTED.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.

&&

$$

UPDATE...MR
SYNOPSIS...NS
SHORT TERM...MSB
LONG TERM...JPB
AVIATION...MR